US 2002O197559A1 (19) United States (12) Patent Application Publication (10) Pub. No.: US 2002/0197559 A1 Nishi et al. (43) Pub. Date: Dec. 26, 2002

(54) POLYMERS, RESIST COMPOSITIONS AND (57) ABSTRACT PATTERNING PROCESS, NOVEL TETRAHYDROFURAN COMPOUNDS AND THER PREPARATION A polymer comprising recurring units of formula (1-1) or (1-2) wherein R', R, R and Rare H or alkyl, or R and R, (75) Inventors: Tsunehiro Nishi, Nakakubiki-gun (JP); and RandR' taken together may form a ring with each pair Takeshi Kinsho, Nakakubiki-gun (JP); being alkylene, and k is 0 or 1 and having a MW of Seiichiro Tachibana, Nakakubiki-gun 1,000-500,000 is novel. A resist composition comprising the (JP); Takeru Watanabe, polymer as a base resin is Sensitive to high-energy radiation, Nakakubiki-gun (JP); Koji Hasegawa, has excellent Sensitivity, resolution, etching resistance, and Nakakubiki-gun (JP); Tomohiro minimized Swell and lends itself to micropatterning with Kobayashi, Nakakubiki-gun (JP) electron beams or deep-UV. Correspondence Address: MILLEN, WHITE, ZELANO & BRANIGAN, (1-1) P.C. 2200 CLARENDON BILVD. SUTE 1400 (...) ARLINGTON, VA 22201 (US) (73) Assignee: Shin-Etsu Chemical Co., Ltd., Tokyo (c), (JP) R R3 (21) Appl. No.: 10/126,877 R2 O R4 (22) Filed: Apr. 22, 2002 (30) Foreign Application Priority Data ( ) (1-2) O Apr. 23, 2001 (JP)...... 2001-1241.26 Apr. 23, 2001 (JP)...... 2001-1241.37 Publication Classification k (51) Int. Cl." ...... G03F 7/038; CO8G 65/34; R R3 GO3F 7/38; G03F 7/40 (52) U.S. Cl...... 430/270.1; 528/425; 528/271; R2 O R4 525/88; 525/165; 430/296; 430/330; 430/311 US 2002/0197559 A1 Dec. 26, 2002

POLYMERS, RESIST COMPOSITIONS AND account of Swelling are rejected. While a finer pattern rule is PATTERNING PROCESS, NOVEL being demanded, there is a need to have a resist material TETRAHYDROFURAN COMPOUNDS AND THEIR which is not only Satisfactory in Sensitivity, resolution, and PREPARATION etching resistance, but fully restrained from Swelling. 0001) This invention relates to (i) a polymer comprising Specific recurring units, (ii) a resist composition comprising SUMMARY OF THE INVENTION the polymer as a base resin, (iii) a patterning process using the resist composition, (iv) a novel tetrahydrofuran com 0006 Therefore, an object of the present invention is to pound useful as a monomer to form the polymer, and (v) a provide (i) a polymer having improved reactivity, robustness method for preparing the tetrahydrofuran compound. and Substrate adhesion as well as minimized Swell during development, (ii) a resist composition comprising the poly BACKGROUND OF THE INVENTION mer as a base resin, which has a higher resolution and etching resistance than conventional resist compositions, 0002 While a number of recent efforts are being made to (iii) a patterning process using the resist composition, (iv) a achieve a finer pattern rule in the drive for higher integration novel tetrahydrofuran compound useful as a monomer to and operating Speeds in LSI devices, deep-ultraViolet lithog form the polymer, and (v) a method for preparing the raphy is thought to hold particular promise as the next tetrahydrofuran compound. generation in microfabrication technology. In particular, photolithography using a Krf or Arf excimer laser as the 0007. It has been found that novel polymers comprising light Source is Strongly desired to reach the practical level as recurring units of the following general formula (1-1) or the micropatterning technique capable of achieving a feature (1-2) and having a weight average molecular weight of size of 0.3 um or less. 1,000 to 500,000, which are produced by the method to be 0.003 For resist materials for use with a Krf excimer described later, have improved reactivity, robustneSS or lasers, polyhydroxystyrene having a practical level of trans rigidity and Substrate adhesion as well as an appropriately mittance and etching resistance is, in fact, a Standard base high Solubility and minimized Swell in a developer, that a resin. For resist materials for use with Arf excimer lasers, resist composition comprising the polymer as the base resin polyacrylic or polymethacrylic acid derivatives and poly has a high resolution and etching resistance, and that this mers containing aliphatic cyclic compounds in the backbone resist composition lends itself to precise micropatterning. are under investigation. All these polymers have advantages 0008. In a first aspect, the invention provides a polymer and disadvantages, and none of them have been established comprising recurring units of the following general formula as the Standard base resin. (1-1) or (1-2) and having a weight average molecular weight 0004 More particularly, resist compositions using of 1,000 to 500,000. derivatives of polyacrylic or polymethacrylic acid have the advantages of high reactivity of acid-decomposable groups and good Substrate adhesion and give relatively Satisfactory ( ) (1-1) results with respect to Sensitivity and resolution, but have extremely low etching resistance and are impractical because the resin backbone is weak. On the other hand, resist compositions using polymers containing alicyclic com pounds in their backbone have a practically acceptable level of etching resistance because the resin backbone is robust, (C) k but are very low in Sensitivity and resolution because the R R3 reactivity of acid-decomposable protective groups is extremely low as compared with those on the (meth)acrylic R2 O R4 polymers. Since the backbone of the resin is too robust, Substrate adhesion is poor. These compositions are thus impractical as well. ( ) (1-2) O 0005 Both the (meth)acrylic and alicyclic backbone sys tems commonly have the problem of pattern disruption due to Swelling of resist film. Resist compositions based on these Systems have been designed So as to improve their resolution performance by increasing the difference in dissolution rate k before and after exposure, and as a consequence, they R R3 eventually become highly hydrophobic. Highly hydrophobic resist compositions, when applied as a film and processed R2 O R4 with a developer, can maintain the film tenaciously in unexposed regions and allow the film to be instantaneously dissolved in over-exposed regions, while relatively-broad 0009 Herein each of R', R, R and R' is hydrogen or a exposed regions therebetween allow penetration of the Straight, branched or cyclic alkyl group of 1 to 15 carbon developer, but are kept undissolved, that is, Swollen. At the atoms, or a pair of R' and R and a pair of R and R' taken very Small pattern size for which an Arf excimer laser is together may form a ring wherein each said pair is a Straight, actually used, those resist compositions which allow adja branched or cyclic alkylene group of 2 to 15 carbon atoms cent pattern Strips to be joined together and disrupted on and k is equal to 0 or 1. US 2002/0197559 A1 Dec. 26, 2002

0010. In one preferred embodiment, the polymer in combination with recurring units of the following general includes, in addition to the recurring units of formula (1-1), formula (2-1), and recurring units of the following general recurring units of the following general formula (2-1). formula (3).

(2-1) (2-1)

(3) 0011) Herein R is hydrogen, methyl or CHCOR"; R is hydrogen, methyl or COR"; R' which may be identical or O- Y A O different in R and R is a straight, branched or cyclic alkyl (4) group of 1 to carbon atoms; R is an acid labile group; R is R6 R5 Selected from the class consisting of a halogen atom, a hydroxyl group, a Straight, branched or cyclic alkoxy, acy ( ) loxy or alkylsulfonyloxy group of 1 to 15 carbon atoms, and H O a Straight, branched or cyclic alkoxycarbonyloxy or alkoxy alkoxy group of 2 to 15 carbon atoms, in which Some or all of the hydrogen atoms on constituent carbon atoms may be Substituted with halogen atoms, Z is a single bond or a 0.015. Herein k", p, R to R and Y are as defined above, Straight, branched or cyclic (p+2)-valent hydrocarbon group R is hydrogen, methyl or CH-Co.R, R is hydrogen, of 1 to 5 carbon atoms, in which at least one methylene may methyl or COR", R' which may be identical or different in be Substituted with oxygen to form a chain-like or cyclic R and R is a straight, branched or cyclic alkyl group of 1 ether or two hydrogen atoms on a common carbon may be to 15 carbon atoms, and R is an acid labile group. Substituted with oxygen to form a ketone, k" is 0 or 1; and p is 0, 1 or 2. 0016. In a still further preferred embodiment, the poly 0012. In another preferred embodiment, the polymer mer includes, in addition to the recurring units of formula includes, in addition to the recurring units of formula (1-1), (1-2), recurring units of the following general formula (2-2). recurring units of the following general formulae (2-1) and (2-2) (2-1)

(3) 0.017. Herein k", p and R to R are as defined above. 0018. In a second aspect, the invention provides a resist composition comprising the polymer defined above. 0019. In a third aspect, the invention provides a process 0013 Hereink', p and R to Rare as defined above, Y is for forming a resist pattern comprising the Steps of applying -O- or -(NR') , and R' is hydrogen or a straight, the resist composition onto a Substrate to form a coating, branched or cyclic alkyl group of 1 to 15 carbon atoms. heat treating the coating and then exposing it to high-energy 0.014. In a further preferred embodiment, the polymer radiation or electron beams through a photo mask, and includes, in addition to the recurring units of formula (1-1), optionally heat treating the exposed coating and developing recurring units of the following general formula (4) alone or it with a developer. US 2002/0197559 A1 Dec. 26, 2002

0020. In a fourth aspect, the invention provides a tetrahy by converting a diol compound of the following general drofuran compound of the following general formula (5). formula (7) to a compound having an eliminatable group X of the following general formula (8-1) and/or (8–2), and treating the compound with a base for cyclization. (5) (c), R1 (),k e. R1 O R2 R2 OHHO 0021 Herein R, R and k are as defined above. (7) 0022. The tetrahydrofuran compound is preferably of the following general formula (6).

(6)

0023. Herein R and R are as defined above. 0024. In a fifth aspect, the invention provides a method for preparing a tetrahydrofuran compound of the following general formula (5), comprising the step (a) of Subjecting a diol compound of the following general formula (7) to intramolecular dehydration. (C), R1 (),s k e. R1 O R2 R2 (5) OHHO (7) 0027) Herein R, R and k are as defined above, X is halogen, alkylsulfonyloxy or arylsulfonyloxy, Step (a) rep resents halogen-Substitution reaction, alkylsulfonylation reaction or arylsulfonylation reaction on hydroxyl, and Step (b) represents HX-eliminating reaction. (c), 0028. The polymer comprising recurring units of formula R1 (1-1) or (1-2) has high robustness due to the inclusion of a O R2 bridged aliphatic ring in the backbone. AS opposed to a polar group introduced at a Site Spaced apart from the backbone, (5) a highly polar ether site positioned within the backbone allows for rapid transition from the penetration of a devel 0025 Herein R, R and k are as defined above, and step oper to the dissolution of the resin, during which period little (a) represents dehydration reaction. Swelling occurs. In addition, Since Small amounts of the recurring units of formula (1-1) or (1-2) introduced are 0026. In an alternative embodiment, a tetrahydrofuran Sufficient to fully exert the Swell Suppressing effect and the compound of the following general formula (5) is prepared substrate bonding effect, the units for establishing differen US 2002/0197559 A1 Dec. 26, 2002

tial dissolution rate Such as blocked carboxylic acid units 0033 Subgenus (I) include polymers comprising, in addi can be introduced in relatively large amounts, eventually tion to the recurring units of formula (1-1), recurring units enhancing Sensitivity and resolution. Therefore, a resist of the following general formula (2-1). composition using the inventive polymer as a base resin Satisfies all the performance factors of Sensitivity, resolution and etching resistance, is fully restrained from Swelling (2-1) upon development, and is thus very useful in forming micropatterns.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 0029 Polymer 0030 Polymers or high molecular weight compounds comprising recurring units of the following general formula (1-1) or (1-2) according to the invention are novel. The polymers have a weight average molecular weight of 1,000 0034) Herein R is hydrogen, methyl or CHCOR"; R is to 500,000. hydrogen, methyl or COR"; R' which may be identical or different in R and R is a straight, branched or cyclic alkyl group of 1 to 15 carbon atoms; R is an acid labile group; R' (1-1) is Selected from among a halogen atom, a hydroxyl group, a Straight, branched or cyclic alkoxy, acyloxy or alkylsul (). fonyloxy group of 1 to 15 carbon atoms, and a Straight, V. A branched or cyclic alkoxycarbonyloxy or alkoxyalkoxy group of 2 to 15 carbon atoms, in which Some or all of the hydrogen atoms on constituent carbon atoms may be Sub Auk Stituted with halogen atoms; Z is a single bond or a Straight, R R3 branched or cyclic (p+2)-valent hydrocarbon group of 1 to R2 O R4 5 carbon atoms, in which at least one methylene may be Substituted with oxygen to form a chain-like or cyclic ether or two hydrogen atoms on a common carbon may be Substituted with Oxygen to form a ketone, k is O or 1; and ( ) (1-2) p is 0, 1 or 2. O 0035) Subgenus (II) include polymers comprising, in addition to the recurring units of formula (1-1), recurring units of the following general formulae (2-1) and (3).

k R R3 (2-1) R2 O R4

0031 Herein each of R', R, R and R' is hydrogen or a Straight, branched or cyclic alkyl group of 1 to 15 carbon atoms. Suitable alkyl groups include methyl, ethyl, propyl, isopropyl, n-butyl, Sec-butyl, tert-butyl, tert-amyl, n-pentyl, n-hexyl, cyclopentyl, cyclohexyl, ethylcyclopentyl, butylcy clopentyl, ethylcyclohexyl, butylcyclohexyl, adamantyl, ethyladamantyl, and butyladamantyl. A pair of RandR and (3) a pair of R and R' taken together may form a ring. In that event, the combination of R' with R and the combination of R with R" each are a straight, branched or cyclic alkylene group of 2 to 15 carbon atoms, Such as ethylene, trimeth ylene, tetramethylene and pentamethylene as well as other 0036) Hereink', p and R to Rare as defined above, Y is alkylene groups obtained by eliminating one hydrogen atom -O- or -(NR') , and R' is hydrogen or a straight, from the above-exemplified alkyl groups. The Subscript k is branched or cyclic alkyl group of 1 to 15 carbon atoms. equal to 0 or 1. 0037 Subgenus (III) include polymers comprising, in 0.032 More specifically, the polymers of the invention are addition to the recurring units of formula (1-1), recurring divided into the following four Subgenuses of polymers. units of the following general formula (4) alone or in US 2002/0197559 A1 Dec. 26, 2002 combination with recurring units of the following general 0042 R is selected from among a halogen atom, a formula (2-1), and recurring units of the following general hydroxyl group, a Straight, branched or cyclic alkoxy, acy formula (3). loxy or alkylsulfonyloxy group of 1 to 15 carbon atoms, and a Straight, branched or cyclic alkoxycarbonyloxy or alkoxy (2-1) alkoxy group of 2 to 15 carbon atoms, in which Some or Iall ( ) of the hydrogen atoms on constituent carbon atoms may be substituted with halogen atoms. Exemplary of Rare fluoro, chloro, bromo, hydroxyl, methoxy, ethoxy, propoxy, isopro poxy, n-butoxy, Sec-butoxy, tert-butoxy, tert-amyloxy, n-pentoxy, n-hexyloxy, cyclopentyloxy, cyclohexyloxy, eth R6 is ylcyclopentyloxy, butylcyclopentyloxy, ethylcyclohexy loxy, butylcyclohexyloxy, adamantyloxy, ethyladamanty H Z-(R') loxy, butyladamantyloxy, formyloxy, acetoxy, ethylcarbonyloxy, pivaloyloxy, methaneSulfonyloxy, o—( 8 OR ethaneSulfonyloxy, n-butaneSulfonyloxy, trifluoroacetoxy, (3) trichloroacetoxy, 2,2,2-trifluoroethylcarbonyloxy, meth oxymethoxy, 1-ethoxyethoxy, 1-ethoxypropoxy, 1-tert-bu toxyethoxy, 1-cyclohexyloxyethoxy, 2-tetrahydrofurany O - Y A O (4) loxy, 2-tetrahydropyranyloxy, methoxycarbonyloxy, R6 R5 ethoxycarbonyloxy, and tert-butoxycarbonyloxy. ( ) 0.043 Y is -O- or -(NR')— wherein R' is hydro H O gen or a Straight, branched or cyclic alkyl group of 1 to 15 R8C5 carbon atoms, examples of which are as exemplified for R' and R7. 0038 Herein k", p, R to R and Y are as defined above, 0044 Z is a single bond or a straight, branched or cyclic R is hydrogen, methyl or CHCOR7, R is hydrogen, (p+2)-valent hydrocarbon group of 1 to 5 carbon atoms, in methyl or Co.R", R7 which may be identical or different in which at least one methylene may be substituted with R and R is a straight, branched or cyclic alkyl group of 1 oxygen to form a chain-like or cyclic ether or two hydrogen to 15 carbon atoms, and R is an acid labile group. atoms on a common carbon may be Substituted with oxygen 0039 Subgenus (IV) include polymers comprising, in to form a ketone. In case of p=0, for example, exemplary Z addition o the recurring units of formula (1-2), recurring groups are methylene, ethylene, trimethylene, tetramethyl units of he following general formula (2-2). ene, pentamethylene, hexamethylene, 1,2-propanediyl, 1,3- butanediyl, 1-oxo-2-oxapropane-1,3-diyl, and 3-methyl-1- OXO-2-oxabutane-1,4-diyl. In case of pz0, exemplary Z (2-2) groups are (p+2)-valent groups obtained by eliminating one or two hydrogen atoms from the above-exemplified groups. 0.045. The acid labile groups represented by R and R' may be Selected from a variety of Such groups. Examples of the acid labile group are groups of the following general formulae (L1) to (L4), tertiary alkyl groups of 4 to 20 carbon atoms, preferably 4 to 15 carbon atoms, trialkylsilyl groups in which each alkyl moiety has 1 to 6 carbon atoms, and OXoalkyl groups of 4 to 20 carbon atoms.

(L1) 0040 Herein k", p and R to R are as defined above. RLO1 0041) More particularly, R is hydrogen, methyl or CH,Co.R', and R is hydrogen, methyl or CHCO.R. R. – ORL03 is hydrogen, methyl or COR', and R is hydrogen, methyl lo or COR7. R7 and R7 which may be identical or different (L.2) between R and R and between R and R', respectively, Stand for Straight, branched or cyclic alkyl groups of 1 to 15 (CH3)-6-ORL04 carbon atoms, Such as, for example, methyl, ethyl, propyl, (L3) isopropyl, n-butyl, Sec-butyl, tert-butyl, tert-amyl, n-pentyl, RL05 n-hexyl, cyclopentyl, cyclohexyl, ethylcyclopentyl, butylcy clopentyl, ethylcyclohexyl, butylcyclohexyl, adamantyl, (CH2) ethyladamanty1 and butyladamantyl. R and R stand for X)(CHFCH) acid labile groups to be described later. US 2002/0197559 A1 Dec. 26, 2002

Examples of the monovalent hydrocarbon group which may -continued contain a hetero atom include Straight, branched or cyclic (L4)

alkyl groupS. Such as methyl, ethyl, propyl, isopropyl, n-bu tyl, Sec-butyl, tert-butyl, tert-amyl, n-pentyl, n-hexyl, cyclo pentyl, and cyclohexyl, and Substituted groups in which Some hydrogen atoms on the foregoing groups are Substi tuted with hydroxyl, alkoxy, carboxy, alkoxycarbonyl, OXo, RL12 RL10 RL16 amino, alkylamino, cyano, mercapto, alkylthio, Sulfo or RL06 RL08 other groups. Exemplary aryl groups are phenyl, methylphe nyl, naphthyl, anthryl, phenanthryl, and pyrenyl. Letter m is 0046. In these formulae and throughout the specification, equal to 0 or 1, n is equal to 0, 1, 2 or 3, and 2 m+n is equal the broken line denotes a free valence bond. R'' and R' to 2 or 3. are hydrogen or Straight, branched or cyclic alkyl groups of 1 to 18 carbon atoms, preferably 1 to 10 carbon atoms. 0050 R'' is a monovalent hydrocarbon group of 1 to 8 Exemplary alkyl groups include methyl, ethyl, propyl, iso carbon atoms which may contain a hetero atom or a Substi propyl, n-butyl, Sec-butyl, tert-butyl, cyclopentyl, cyclo tuted or unsubstituted aryl group of 6 to 20 carbon atoms. hexyl, 2-ethylhexyl, and n-octyl. R'' is a monovalent Examples of these groups are the same as exemplified for hydrocarbon group of 1 to 18 carbon atoms, preferably 1 to RLO5. 10 carbon atoms, which may contain a hetero atom Such as oxygen, examples of which include unsubstituted Straight, 0051) R''' to R' independently represent hydrogen or branched or cyclic alkyl groups and Straight, branched or monovalent hydrocarbon groups of 1 to 15 carbon atoms cyclic alkyl groups in which Some hydrogen atoms are which may contain a hetero atom. Exemplary hydrocarbon replaced by hydroxyl, alkoxy, OXO, amino, alkylamino or the groups are Straight, branched or cyclic alkyl groupS Such as like. Illustrative examples are the Substituted alkyl groups methyl, ethyl, propyl, isopropyl, n-butyl, Sec-butyl, tert shown below. butyl, tert-amyl, n-pentyl, n-hexyl, n-octyl, n-nonyl, n-decyl, cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentyl ethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl n-1-N-O -nu-'nu-1N1 and cyclohexylbutyl, and Substituted ones of these groups in Y * O which Some hydrogen atoms are replaced by hydroxyl, -N1'N-1\,. alkoxy, carboxy, alkoxycarbonyl, OXO, amino, alkylamino, OH cyano, mercapto, alkylthio, Sulfo or other groups. Alterna tively, R'7 to R', taken together, form a ring (for -n-1\-1-N-O example, a pair of R7 and R', R7 and R', R'' and R09, Ros and RL10, R-11 and R-12, RL13 and RL14, or a similar pair form a ring). Each of R'7 to R' represents a s y divalent C-C hydrocarbon group which may contain a r O hetero atom, when they form a ring, examples of which are the ones exemplified above for the monovalent hydrocarbon 0047. A pair of Rol and R0, Ro and Ros, or Ro? groups, with one hydrogen atom being eliminated. Two of and R' may form a ring. Each of R', R'' and R'' is R" to R' which are attached to adjoining carbon atoms a Straight or branched alkylene group of 1 to 18 carbon (for example, a pair of R'' and R', R'' and RL15, RL13 atoms, preferably 1 to 10 carbon atoms when they form a and R'', or a similar pair) may bond together directly to ring. form a double bond. 0048) R' is a tertiary alkyl group of 4 to 20 carbon 0052) Of the acid labile groups of formula (L1), the atoms, preferably 4 to 15 carbon atoms, a trialkylsilyl group Straight and branched ones are exemplified by the following in which each alkyl moiety has 1 to 6 carbon atoms, an groupS. OXoalkyl group of 4 to 20 carbon atoms, or a group of formula (L1). Exemplary tertiary alkyl groups are tert-butyl, tert-amyl, 1,1-diethylpropyl, 2-cyclopentylpropan-2-yl, 2-cyclohexylpropan-2-yl, 2-(bicyclo2.2.1]heptan-2-yl)pro -n1 -n1n -n1n-1 pan-2-yl, 2-(adamantan-1-yl)propan-2-yl, 1-ethylcyclopen tyl, 1-butylcyclopentyl, 1-ethylcyclohexyl, 1-butylcyclo hexyl, 1-ethyl-2-cyclopentenyl, 1-ethyl-2-cyclohexenyl, -n1n-1\ --> 2-methyl-2-adamantyl, and 2-ethyl-2-adamantyl. Exem plary trialkylsilyl groups are trimethylsilyl, triethylsilyl, and dimethyl-tert-butylsilyl. Exemplary oxoalkyl groups are 3-oxocyclohexyl, 4-methyl-2-OXooxan-4-yl, and 5-methyl -k- C 2-OXOOXolan-5-yl. Letter y is an integer of 0 to 6. 0049) R' is a monovalent hydrocarbon group of 1 to 8 carbon atoms which may contain a hetero atom or a Substi 1S tuted or unsubstituted aryl group of 6 to 20 carbon atoms. US 2002/0197559 A1 Dec. 26, 2002

-continued -continued

0057 Examples of the tertiary alkyl groups of 4 to 20 0053) Of the acid labile groups of formula (L1), the cyclic carbon atoms, trialkylsilyl groups in which each alkyl moi ones are, for example, tetrahydrofuran-2-yl, 2-methyltet ety has 1 to 6 carbon atoms, and OXO alkyl groups of 4 to 20 rahydrofuran-2-yl, tetrahydropyran-2-yl, and 2-methyltet carbon atoms are as exemplified for R''. rahydropyran-2-yl. 0058 Illustrative, non-limiting, examples of the recurring units of formula (1-1) are given below. 0054 Examples of the acid labile groups of formula (L2) include tert-butoxycarbonyl, tert-butoxycarbonylmethyl, tert-amyloxycarbonyl, tert-amyloxycarbonylmethyl, 1,1-di ethylpropyloxycarbonyl, 1,1-diethylpropyloxycarbonyl-me thyl, 1-ethylcyclopentyloxycarbonyl, 1-ethylcyclopentyl oxycarbonylmethyl, 1-ethyl-2-cyclopentenyloxycarbonyl, 1-ethyl-2-cyclopentenyloxycarbonylmethyl, 1-ethoxy ethoxy-carbonylmethyl, 2-tetrahydropyranyloxycarbonyl O O O methyl, and 2-tetrahydrofuranyloxycarbonylmethyl groups. ( ) ( ) 0055 Examples of the acid labile groups of formula (L3) include 1-methylcyclopentyl, 1-ethylcyclopentyl, 1-n-pro pylcyclopentyl, 1-isopropylcyclopentyl, 1-n-butyl-cyclo pentyl, 1-Sec-butylcyclopentyl, 1-methylcyclohexyl, 1-eth ylcyclohexyl, 3-methyl-1-cyclopenten-3-yl, 3-ethyl-1- cyclopenten-3-yl, 3-methyl-1-cyclohexen-3-yl, and 3-ethyl ( ) ( ) 1-cyclohexen-3-yl groups. 0056 The acid labile groups of formula (L4) are exem plified by the following groups.

) ( )

US 2002/0197559 A1 Dec. 26, 2002

-continued -continued ( (...) ) ( O ) ( O )

-X) O O ( ) ( ) O O

( ) 0059 Illustrative, non limiting, examples of the recurring O units of formula (1-2) are given below

( ) ( )

0060 Illustrative, non-limiting, examples of the recurring units of formula (2-1) are given below.

O O

US 2002/0197559 A1 Dec. 26, 2002

-continued -continued )

O O

O O 0061 Illustrative, non-limiting, examples of the recurring ?yO OlyO units of formula (2-2) are given below.

O O)- O) Y r) co - t * US 2002/0197559 A1 Dec. 26, 2002 10

-continued -continued ( ) ( ) - - O O

( ) ( ) - - O O Oly 0063. If desired, the polymers of the invention may further contain recurring units of one or more types Selected from units of the following general formulae (M1) to (M8-2). 0.062 Illustrative, non-limiting, examples of the recurring units of formula (4) are given below. (M1) R02 R001

H COR004 (M2) ()R02 ( R001) H cOR009 (M3) R02 R001

H COR014 (M4) 002) {R001 H COR015 (M5-1)

R005 k R008 R0063. R007 US 2002/0197559 A1 Dec. 26, 2002 11

-continued -continued (M6-1) (M8-2) ( ) ( )

R010 *R013 R002 R001 R011 R012

(M7-1) ( ) 0064. Herein, R' is hydrogen, methyl or CHCOR'. R’ is hydrogen, methyl or COR. R' is a straight, branched or cyclic alkyl group of 1 to 15 carbon atoms. R' is hydrogen or a monovalent hydrocarbon group of 1 to 15 carbon atoms having a carboxyl or hydroxyl group. At least R002 *R001 one of R' to R' represents a monovalent hydrocarbon H COR014 group of 1 to 15 carbon atoms having a carboxyl or hydroxyl group while the remaining R's independently represent hydrogen or a Straight, branched or cyclic alkyl group of 1 (M8-1) ( ) to 15 carbon atoms. Alternatively, R to R', taken together, may form a ring, and in that event, at least one of R' to R' is a divalent hydrocarbon group of 1 to 15 carbon atoms having a carboxyl or hydroxyl group, while the remaining R's are independently single bonds or R002 R001 Straight, branched or cyclic alkylene groups of 1 to 15 carbon atoms. R' is a monovalent hydrocarbon group of 2 H COR015 to 15 carbon atoms containing at least one partial Structure Selected from among ether, aldehyde, ketone, ester, carbon (M5-2) ate, acid anhydride, amide and imide. At least one of R' to ( X ) R' is a monovalent hydrocarbon group of 2 to 15 carbon atoms containing at least one partial Structure Selected from among ether, aldehyde, ketone, ester, carbonate, acid anhy dride, amide and imide, while the remaining R's are inde pendently hydrogen or Straight, branched or cyclic alkyl R005 *R008 groups of 1 to 15 carbon atoms. R' to R', taken together, may form a ring, and in that event, at least one of R' to R006 R007 R is a divalent hydrocarbon group of 1 to 15 carbon atoms containing at least one partial Structure Selected from among ether, aldehyde, ketone, ester, carbonate, acid anhydride, (M6-2) amide and imide, while the remaining R's are independently ( X ) Single bonds or Straight, branched or cyclic alkylene groups of 1 to 15 carbon atoms. R'' is a polycyclic hydrocarbon group having 7 to 15 carbon atoms or an alkyl group containing a polycyclic hydrocarbon group. R' is an acid R010 *R013 labile group. X is CH or an oxygen atom. Letter k is equal to 0 or 1. R011 R012

(M7-2) 0065) More illustratively, R' is a straight, branched or cyclic alkyl group of 1 to 15 carbon atoms, for example, methyl, ethyl, propyl, isopropyl, n-butyl, Sec-butyl, tert butyl, tert-amyl, n-pentyl, n-hexyl, cyclopentyl, cyclohexyl, ethylcyclopentyl, butylcyclopentyl, ethylcyclohexyl, butyl cyclohexyl, adamantyl, ethyladamantyl, and butyladaman tyl. 0066) R' is hydrogen or a monovalent hydrocarbon group of 1 to 15 carbon atoms having a carboxyl or hydroxyl US 2002/0197559 A1 Dec. 26, 2002 group, for example, hydrogen, carboxyethyl, carboxybutyl, 3-yloxycarbonyl, 4-methyl-2-OXOOXan-4-yloxycarbonyl, carboxycyclopentyl, carboxycyclohexyl, carboxynorbornyl, 2-oxo-1,3-dioxolan-4-ylmethyloxycarbonyl, and 5-methyl carboxyadamantyl, hydroxyethyl, hydroxybutyl, hydroxy 2-OXOOXolan-5-yloxycarbonyl. Examples of the Straight, cyclopentyl, hydroxycyclohexyl, hydroxynorbornyl, and branched or cyclic alkyl groups of 1 to 15 carbon atoms are hydroxyadamantyl. the same as exemplified for R'. 0067. At least one of R to R' represents a monova 0.071) R' to R', taken together, may form a ring, and lent hydrocarbon group of 1 to 15 carbon atoms having a in that event, at least one of R' to R' is a divalent carboxyl or hydroxyl group while the remaining R's inde hydrocarbon group of 1 to 15 carbon atoms containing at pendently represent hydrogen or a Straight, branched or least one partial Structure Selected from among ether, alde cyclic alkyl group of 1 to 15 carbon atoms. Examples of the hyde, ketone, ester, carbonate, acid anhydride, amide and carboxyl or hydroxyl-bearing monovalent hydrocarbon imide, while the remaining R's are independently Single group of 1 to 15 carbon atoms include carboxy, carboxym bonds or Straight, branched or cyclic alkylene groups of 1 to ethyl, carboxyethyl, carboxybutyl, hydroxymethyl, 15 carbon atoms. Examples of the divalent hydrocarbon hydroxyethyl, hydroxybutyl, 2-carboxyethoxycarbonyl, group of 1 to 15 carbon atoms containing at least one partial 4-carboxybutoxycarbonyl, 2-hydroxyethoxycarbonyl, 4-hy Structure Selected from among ether, aldehyde, ketone, ester, carbonate, acid anhydride, amide and imide include 2-OX droxybutoxycarbonyl, carboxycyclopentyloxycarbonyl, car apropane-1,3-diyl, 1,1-dimethyl-2-oxapropane-1,3-diyl, boxycyclohexyloxycarbonyl, carboxynorbornyl-oxycarbo 1-OXO-2-oxapropane-1,3-diyl, 1,3-dioxo-2-oxapropane-1,3- nyl, carboxyadamantyloxycarbonyl, hydroxycyclo diyl, 1-oxo-2-oxabutane-1,4-diyl, and 1,3-dioxo-2-oxabu pentyloxycarbonyl, hydroxycyclohexyloxycarbonyl, tane-1,4-diyl, as well as the groups exemplified as the hydroxy-norbornyloxycarbonyl, and hydroxyadamanty monovalent hydrocarbon group of 1 to 15 carbon atoms loxycarbonyl. Examples of the Straight, branched or cyclic containing at least one partial Structure Selected from among alkyl group of 1 to 15 carbon atoms are the same as ether, aldehyde, ketone, ester, carbonate, acid anhydride, exemplified for R. amide and imide, with one hydrogen atom eliminated there 0068 Alternatively, R' to R', taken together, may from. Examples of the Straight, branched or cyclic alkylene form a ring, and in that event, at least one of R' to R' is groups of 1 to 15 carbon atoms include the groups exem a divalent hydrocarbon group of 1 to 15 carbon atoms having plified for R', with one hydrogen atom eliminated there a carboxyl or hydroxyl group, while the remaining R's are from. independently single bonds or Straight, branched or cyclic 0072) R' is a polycyclic hydrocarbon group having 7 to alkylene groups of 1 to 15 carbon atoms. Examples of the 15 carbon atoms or an alkyl group containing a polycyclic carboxyl or hydroxyl-bearing divalent hydrocarbon group of hydrocarbon group, for example, norbornyl, bicyclo3.3.1- 1 to 15 carbon atoms include the groups exemplified as the nonyl, tricyclo[5.2.1. 0° decyl, adamantyl, ethyladaman carboxyl or hydroxyl-bearing monovalent hydrocarbon tyl, butyladamantyl, norbornylmethyl, and adamantylm group, with one hydrogen atom eliminated therefrom. ethyl. Examples of the Straight, branched or cyclic alkylene groups of 1 to 15 carbon atoms include the groups exemplified for 0073) R' is an acid labile group, examples of which are R", with one hydrogen atom eliminated therefrom. the same as described above. X is CH or an oxygen atom. Letter k is equal to 0 or 1. 0069) R' is a monovalent hydrocarbon group of 2 to 15 carbon atoms containing at least one partial Structure 0.074 The recurring units of formulae (M1) to (M8-2) are Selected from among ether, aldehyde, ketone, ester, carbon effective for imparting Such desired properties as developer ate, acid anhydride, amide and imide, for example, meth affinity, Substrate adhesion and etching resistance to a resist oxymethyl, methoxyethoxymethyl, 2-OXOOXolan-3-yl, composition based on a polymer comprising these recurring 2-OXOOXolan-4-yl, 4,4-dimethyl-2-oxooxolan-3-yl, 4-me units. By adjusting the content of these recurring units, the thyl-2-oxooxan-4-yl, 2-oxo-1,3-dioxolan-4-ylmethyl, and performance of the resist composition can be finely adjusted. 5-methyl-2-oxooxolan-5-yl. 0075. The polymers of the invention have a weight 0070. At least one of R' to R' is a monovalent average molecular weight of about 1,000 to 500,000, pref hydrocarbon group of 2 to 15 carbon atoms containing at erably about 3,000 to 100,000, as measured by gel perme least one partial Structure Selected from among ether, alde ation chromatography (GPC) using a polystyrene Standard. hyde, ketone, ester, carbonate, acid anhydride, amide and Outside the range, the etching resistance may become imide, while the remaining R's are independently hydrogen extremely low and the resolution may become low because or Straight, branched or cyclic alkyl groups of 1 to 15 carbon a Substantial difference in rate of dissolution before and after atoms. Examples of the monovalent hydrocarbon group of 2 exposure is lost. to 15 carbon atoms containing at least one partial Structure Selected from among ether, aldehyde, ketone, ester, carbon 0076. The polymer of the invention can be prepared ate, acid anhydride, amide and imide include methoxym through copolymerization reaction using a compound of the ethyl, methoxymethoxymethyl, formyl, methylcarbonyl, following general formula (1a) as a first monomer, one, two formyloxy, acetoxy, pivaloyloxy, formyloxymethyl, or three members Selected from compounds of the following acetoxy-methyl, pivaloyloxymethyl, methoxycarbonyl, general formulae (2a) to (4a) as Second to fourth monomers, 2-OXOOXolan-3-yloxycarbonyl, 4,4-dimethyl-2-oxooxolan and optionally, one or more members Selected from com US 2002/0197559 A1 Dec. 26, 2002 13 pounds of the following general formulae (M1a) to (M8a) as Subsequent monomers. -continued (M5a)

(1a)

W A R006 .R007 (...) k R1 R3 (M6a) R2 O R4 (2a)

R011 .R012 H .Z-(R') (M7a)

o—(OR8 (3a)

O Y O H .COR014 (4a) (M8a) R6 R5

2.R8C O H .COR015 0077. Herein, k, k", p, R to R, R to R and Y are as defined above. 0078 Herein, k, R' to R', and Xare as defined above. 0079. By properly adjusting the proportion of the respec M1a tive monomers used in the copolymerization reaction, the RQ02 R001 ( ) polymer can be tailored So that it may exert the preferred performance when blended in resist compositions. H COR004 0080. In addition to (i) the monomer of formula (1a), (ii) M2a the monomer or monomers of formulas (2a) to (4a), and (iii) R02 R001 ( ) the monomer or monomers of formulae (M1a) to (M8a), the polymer of the invention may have copolymerized there with (iv) another monomer having a carbon-to-carbon double H COR009 bond other than (i) to (iii). Examples of the additional monomer (iv) include Substituted acrylic acid esterS Such as M3a R02 R001 ( ) methyl methacrylate, methyl crotonate, dimethyl maleate, and dimethyl itaconate, unsaturated carboxylic acids Such as maleic acid, fumaric acid and itaconic acid, Substituted or unsubstituted norbornenes Such as norbornene and methyl H COR014 norbornene-5-carboxylate, and unsaturated acid anhydrides M4a R02 R001 ( ) Such as itaconic anhydride. 0081. In the polymers of the invention, the preferred proportion of recurring units based on the respective mono H COR015 mers is in the following range (in mol%), though not limited thereto. US 2002/0197559 A1 Dec. 26, 2002

0082 (I) When the polymer is comprised of recurring 0099 (vi) 0 to 25%, preferablyp y 0 to 20%, and more units of formula (1-1) and recurring units of formula (2-1), preferably 0 to 15% of recurring units based on another it contains OOC. 0.083 (i) 1 to 90%, preferably 5 to 80%, and more 0100 (IV) When the polymer is comprised of recurring preferably 10 to 70% of recurring units of formula (1-1) units of formula (1-2) and recurring units of formula (2-2), based on the monomer of formula (1a), it contains 0084) (ii) 1 to 90%, preferably 5 to 80%, and more preferably 10 to 70% of recurring units of formula (2-1) 0101 (i) 1 to 90%, preferably 5 to 80%, and more based on the monomer of formula (2a), preferably 10 to 70% of recurring units of formula (1-2) based on the monomer of formula (1a), 0085 (iii) 0 to 50%, preferably 0 to 40%, and more preferably 0 to 30% of recurring units of formula 0102) (ii) 1 to 90t, preferably 5 to 80%, and more (M5-1) to (M8-1) based on the monomers of formula preferably 10 to 70% of recurring units of formula (2-2) (M5a) to (M8a), and based on the monomer of formula (2a), O086 iv) 0 to 50%, preferablyp y 0 to 40%, and more 0103 (iii) 0 to 50%, preferably 0 to 40%, and more preferably 0 to 30% of recurring units based on another preferably 0 to 30% of recurring units of formula OOC. (M5-2) to (M8-2) based on the monomers of formula 0087 (II) When the polymer is comprised of recurring (M5a) to (M8a), and units of formula (1-1), recurring units of formula (2-1) and recurring units of formula (3), it contains 0104 (iv) 0 to 50%, preferablyp y 0 to 40%, and more preferably 0 to 30% of recurring units based on another 0088 (i) 1 to 49%, preferably 3 to 45t, and more OOC. preferably 5 to 40% of recurring units of formula (1-1) based on the monomer of formula (1a), 0105. A variety of copolymerization reaction methods may be used for the preparation of the polymer according to 0089 (ii) 1 to 49%, preferably 3 to 45%, and more the invention. The preferred polymerization reaction is radi preferably 5 to 40% of recurring units of formula (2-1) cal polymerization, anionic polymerization or coordination based on the monomer of formula (2a), polymerization. 0090 (iii) 50 mol % of recurring units of formula (3) 0106 For radical polymerization, preferred reaction con based on the monomer of formula (3a), ditions include (a) a Solvent Selected from among hydrocar 0.091 (iv) 0 to 25%, preferably 0 to 20%, and more bons Such as benzene, etherS Such as tetrahydrofuran, alco preferably 0 to 15% of recurring units of formula hols Such as ethanol, and ketones Such as methyl isobutyl (M5-1) to (M8-1) based on the monomers of formula ketone, (b) a polymerization initiator Selected from azo (M5a) to (M8a), and compounds Such as 2,2'-aZobisisobutyronitrile and perOX ides Such as benzoyl peroxide and lauroyl peroxide, (c) a 0092 (v) 0 to 25%, preferably 0 to 20t, and more temperature of about 0° C. to about 100° C., and (d) a time preferably 0 to 15% of recurring units based on another of about 72 hour to about 48 hours. Reaction conditions OOC. outside the described range may be employed if desired. 0093 (III) When the polymer is comprised of recurring units of formula (1-1), recurring units of formula (4) alone 0107 For anionic polymerization, preferred reaction con or in combination with recurring units of formula (2-1), and ditions include (a) a Solvent Selected from among hydrocar recurring units of formula (3), it contains bons Such as benzene, etherS Such as tetrahydrofuran, and liquid ammonia, (b) a polymerization initiator Selected from 0094) (i) 1 to 49%, preferably 3 to 45%, and more metals. Such as Sodium and potassium, alkyl metals Such as preferably 5 to 40% of recurring units of formula (1-1) n-butyllithium and Sec-butyllithium, ketyl, and Grignard based on the monomer of formula (1a), reagents, (c) a temperature of about -78° C. to about 0°C., 0.095 (ii) 0 to 40%, preferably 0 to 35%, and more (d) a time of about 73 hour to about 48 hours, and (e) a preferably 0 to 30% of recurring units of formula (2-1) Stopper Selected from among proton-donative compounds based on the monomer of formula (2a), Such as methanol, halides Such as methyl iodide, and elec trophilic compounds. Reaction conditions outside the 0.096 (iii) 1 to 80%, preferably 1 to 70%, and more described range may be employed if desired. preferably 1 to 50% of recurring units of formula (4) based on the monomer of formula (4a), 0.108 For coordination polymerization, preferred reac tion conditions include (a) a Solvent Selected from among 0097 (iv) 1 to 49%, preferably 5 to 45%, and more hydrocarbons Such as n-heptane and toluene, (b) a catalyst preferably 10 to 40t of recurring units of formula (3) Selected from Ziegler-Natta catalysts comprising a transition based on the monomer of formula (3a), metal (e.g., titanium) and alkylaluminum, Phillips catalysts 0.098 (v) 0 to 25%, preferably 0 to 20%, and more of metal oxides having chromium or nickel compounds preferably 0 to 15% of recurring units of formula (M1) carried thereon, and olefin-metathesis mixed catalysts as to (M8-1) based on the monomers of formula (M1a) to typified by tungsten and rhenium mixed catalysts, (c) a (M8a), and temperature of about 0° C. to about 100° C., and (d) a time US 2002/0197559 A1 Dec. 26, 2002

of about 72 hour to about 48 hours. Reaction conditions a tetrahydrofuran compound of the following general for outside the described range may be employed if desired. mula (6). Accordingly, the present invention provides novel 0109 The monomer from which the units of formulae tetrahydrofuran compounds and a method for preparing the (1-1) and (1-2) characteristic of the inventive polymers are SC. derived He can be synthesized by first effecting Diels-Alder reaction of maleic anhydride with a furan to form 4,10 dioxatricyclo5.2.1. dec-8-ene-3,5-dione or 6.14,15-tri (5) oxapentacyclo9.2.1.1.0°-'0' pentadec-12-ene-5,7-di one, then effecting nucleophilic addition reaction to carbonyl group Such as Grignard reaction or reduction of the V A acid anhydride moiety with a hydride reducing agent or the like and Subsequent cyclization reaction, or combination (...),W . thereof. R1 O R2 W \ (6)

A . yi . ). {.. . O R2 0113) Herein R, R and k are as defined above. Illustra tive examples of these groups are the Same as exemplified above. (...) (...) 0114 Preferably the preparation of the tetrahydrofuran compound according to the invention starts with a diol (...) (c) (...) compound of the following general formula (7), which in C. k k turn, is readily obtained by reduction of a corresponding R1. R3 R R3 lactone (9) or acid anhydride (10). R2 R4 R2 4 OHHO O R (1a) ) NQ 91 V A V and/or

k k w (...)V (),w co R1 (2. O O R2 O O O R R3 (9) (10) R2 R4 X HO

0110 Herein, k and R' to R' are as defined above, and X is a halogen atom, alkylsulfonyloxy group or arylsulfony loxy group. Step (a) represents Diels-Alder reaction; Step (b) represents reduction with hydride reducing agents or the like, nucleophilic addition reaction Such as Grignard reac tion or a combination thereof, step (c) represents intramo lecular dehydrating cyclization reaction with acids, Salts or phosphorus compounds; step (d) represents halogenation or Sulfonylation reaction; and step (e) represents dehydrohalo genation or desulfonation reaction. 0115. Herein R, R and k are as defined above. Step (a) 0111 Tetrahydrofuran Compound represents reducing reaction. 0112 The starting monomer from which the inventive 0116. A first method of preparing the tetrahydrofuran polymer is produced is preferably a tetrahydrofuran com compound (5) from the diol compound (7) is by intramo pound of the following general formula (5), more preferably lecular dehydration of the diol compound (7). US 2002/0197559 A1 Dec. 26, 2002 16

the step (b) of treating the compound (8-1) and/or (8–2) with a base for cyclization into a tetrahydrofuran compound (...)

Her k (...) (...) (...)7 k o- (--) R 1. (a) 1. (...) (...) and/o k C k R2 2 OH HO O R R1 R1

(7) (5) OHHO HO (7) (8-1) 0117) Herein R, R and k are as defined above, and step (a) represents dehydration reaction. (...) (...) 0118 Better results are obtained from intramolecular dehydration reaction when an acid or a Salt thereof, or a phosphorus reagent is used. k C k R1 R1 0119) Examples of the acid used herein include inorganic acids Such as hydrochloric acid, hydrobromic acid, Sulfuric O R2 acid, nitric acid, perchloric acid, and phosphoric acid and OH X organic acids Such as formic acid, acetic acid, oxalic acid, (8-2) (5) Adbenzoic acid, p-toluenesulfonic acid, and benzene Sulfonic acid, and Salts thereof as well as cation-exchange resins. The amount of acid used is a catalytic amount, 0124. Herein, R', R and k are as defined above, and X is preferably 0.01 to 10 mol, especially 0.01 to 0.5 mol per mol a halogen atom, alkylsulfonyloxy group or arylsulfonyloxy of the diol compound (7). To remove the water formed upon group. Step (a) represents halogen-Substitution reaction, tetrahydrofuran cyclization, it is recommended that the alkylsulfonylation reaction or arylsulfonylation reaction on water be positively removed from the System by azeotropic hydroxyl, and step (b) represents HX-eliminating reaction. distillation using a hydrocarbon Such as n-hexane, n-hep tane, benzene, toluene, Xylene or cumene, for thereby accel 0125 The first step is to synthesize the compound (8-1) erating the reaction. Also, the reaction may be carried out in and/or (8–2) having an eliminatable group. The compound WCUU. (7) has within the molecule two hydroxyl groups, only one of which is converted to an eliminatable group X. When R' 0120 Examples of the phosphorus reagent include hex or R is not hydrogen, that is, when either one or both of R' amethylphosphoric triamide (HMPA), dialkyl azodicar and R are straight, branched or cyclic C-1s alkyl groups or boxylate-triphenylphosphine, triethylphosphine, and potas Rand R together are a straight, branched or cyclic Cls sium carbonate-triphenylphosphine. The amount of alkylene group, one of the two hydroxyl groups is a primary phosphorus reagent used is preferably 0.9 to 10 mol, espe hydroxyl group and the other is a Secondary or tertiary cially 1.0 to 1.2 mol per mol of the diol compound (7). hydroxyl group. It is then relatively easy to convert only one 0121 The reaction temperature and time vary with other hydroxyl group to an eliminatable group X by utilizing a conditions. In one example using triphenylsphosphine and difference in reactivity between the two. In contrast, when carbon tetrachloride, the reaction temperature is room tem both R" and R are hydrogen, the two hydroxyl groups are perature to the reflux temperature, desirably 50° C. to the both primary. Then the amounts of reagents and reaction reflux temperature for rapidly driving the reaction to conditions must be carefully determined in order to convert completion. The reaction time is desirably determined by only one hydroxyl group to an eliminatable group X. monitoring the reaction until the completion by gas chro 0126 In the case of the compound (8-1) or (8–2) having matography (GC) or Silica gel thin-layer chromatography an eliminatable group X which is a halogen atom, X is (TLC) because higher yields are expectable. The reaction preferably chlorine or bromine. In this case, various well time is usually about 1 to about 30 hours. known methods are applicable to the Synthesis of haloalco 0122). From the reaction mixture, the end tetrahydrofuran hol compound (8-1) or (8-2) from diol compound (7). Some compound (5) is obtained by a conventional aqueous work exemplary methods use hydrohalogenic acids Such as hydro up step. If necessary, the end compound (5) is purified by chloric acid and hydrobromic acid, Sulfur reagents Such as any conventional technique Such as distillation, chromatog thionyl chloride and thionyl bromide, and phosphorus raphy or recrystallization. reagents Such as phosphorus trichloride, phosphorus pen tachloride, phosphorus tribromide or triphenylphosphine 0123. A second method of preparing the tetrahydrofuran compound (5) from the diol compound (7) involves the step combined with various halogen Sources. (a) of converting the diol compound (7) to a compound (8-1) 0127. The reaction temperature and time largely vary and/or (8–2) having an eliminatable group Such as a halogen with reagents and conditions. In one example wherein a atom, alkylsulfonyloxy group or arylsulfonyloxy group, and Vilsmeier reagent is prepared using phosphorus pentachlo US 2002/0197559 A1 Dec. 26, 2002 ride in dimethylformamide (DMF) and reacted in situ to mono-p-toluene Sulfonate is Synthesized using p-toluene chlorinate one primary hydroxyl group, a temperature in the Sulfonyl chloride and pyridine as the base and Solvent, a range of -20° C. to room temperature, desirably 0° C. to temperature in the range of -20° C. to room temperature, room temperature is preferred for highselectivity of reaction. desirably 0° C. to room temperature is preferred for the The reaction time is desirably determined by monitoring the completion of reaction and the high purity of the reaction reaction until the completion by gas chromatography (GC) product. The reaction time is desirably determined by moni or Silica gel thin-layer chromatography (TLC) because toring the reaction until the completion by gas chromatog higher yields are expectable. The reaction time is usually raphy (GC) or Silica gel thin-layer chromatography (TLC) about 1 to about 50 hours. because higher yields are expectable. The reaction time is 0128. From the reaction mixture, the end haloalcohol usually about 1 to about 60 hours. compound (8-1) and/or (8–2) is obtained by a conventional 0134) From the reaction mixture, the end sulfonyloxy aqueous work-up step. If necessary, the compound (8-1) compound (8-1) and/or (8–2) is obtained by a conventional and/or (8–2) is purified by any conventional technique Such aqueous work-up step. If necessary, the compound (8-1) as distillation, chromatography or recrystallization. In most and/or (8–2) is purified by any conventional technique Such cases, the crude product has Such a purity that it may be used as distillation, chromatography or recrystallization. In most in the Subsequent Step without purification. cases, the crude product has Such a purity that it may be used 0129. In the case of the compound (8-1) or (8–2) having in the Subsequent Step without purification. an eliminatable group X which is an alkylsulfonyloxy or 0135) In a further embodiment, the compound (8-1) and/ arylsulfonyloxy group, X is preferably a methaneSulfony or (8-2) in which X is an alkylsulfonyloxy or arylsulfony loxy, trifluoromethaneSulfonyloxy, benzeneSulfonyloxy or loxy group can be converted to the haloalcohol compound p-tolueneSulfonyloxy group for availability of their starting (8-1) and/or (8–2) in which X is halogen. materials. In this case, the Sulfonyloxy compound (8-1) or 0.136. In this embodiment, reaction may be performed in (8-2) is conventionally Synthesized by reacting a corre a polar solvent such as dimethylformamide (DMF), dim sponding Sulfonyl halide with the diol compound (7) in a ethylsulfoxide (DMSO) or ethanol at an elevated tempera Solvent in the presence of a base. ture in the range of room temperature to the reflux tempera 0130. The Sulfonyl halide is exemplified by methane ture of the Solvent, using a halide Salt Such as lithium sulfonyl chloride, trifluoromethanesulfonyl chloride, benze chloride, lithium bromide, Sodium bromide or calcium bro neSulfonyl chloride and p-toluenesulfonyl chloride. An mide in more than Stoichiometric amounts. appropriate amount of the Sulfonyl halide used is 0.9 to 10 mol, especially 1.0 to 1.2 mol per mol of the diol compound 0.137 In the second step, a base acts on the compound (7) in order to convert only one of the hydroxyl groups on (8-1) and/or (8–2) having an eliminatable group in a Solvent the diol compound (7) to X. to produce the end tetrahydrofuran compound. Examples of the base used herein include alkoxides Such as Sodium 0131 Examples of the base used herein include organic methoxide, Sodium ethoxide, lithium methoxide, lithium amines Such as pyridine, triethylamine, N,N-dimethylaniline ethoxide, lithium tert-butoxide and potassium tert-butoxide; and 4-dimethylaminopyridine, alkoxides Such as Sodium organic amines Such as pyridine, triethylamine, N,N-dim methoxide, Sodium ethoxide, lithium methoxide, lithium ethylaniline and 4-dimethylaminopyridine, inorganic ethoxide, lithium tert-butoxide and potassium tert-butoxide; hydroxides Such as Sodium hydroxide, lithium hydroxide, inorganic hydroxides Such as Sodium hydroxide, lithium potassium hydroxide, barium hydroxide and tetra-n-buty hydroxide, potassium hydroxide, barium hydroxide and lammonium hydroxide; inorganic carbonates Such as tetra-n-butylammonium hydroxide, inorganic carbonates Sodium carbonate, Sodium hydrogen carbonate, lithium car Such as Sodium carbonate, Sodium hydrogen carbonate, bonate and potassium carbonate, alkyl metal compounds lithium carbonate and potassium carbonate, and metal Such as trityllithium, tritylsodium, tritylpotassium, methyl amides Such as Sodium amide, potassium amide, lithium lithium, phenyllithium, sec-butyllithium, tert-butyllithium diisopropylamide, potassium diisopropylamide, lithium and ethyl magnesium bromide; and metal amides Such as dicyclohexylamide, potassium dicyclohexylamide, lithium Sodium amide, potassium amide, lithium diisopropylamide, 2.2,6,6-tetramethyl-piperidine, lithium bistrimethylsilyla potassium diisopropylamide, lithium dicyclohexylamide, mide, Sodium bistrimethylsilylamide, potassium bistrimeth potassium dicyclohexylamide, lithium 2,2,6,6-tetrameth ylsilylamide, lithium isopropylcyclohexylamide and bromo ylpiperidine, lithium bistrimethyl-silylamide, sodium bistri magnesium diisopropylamide. An appropriate amount of the methylsilylamide, potassium bistrimethylsilylamide, lithium base used is 0.9 to 100 mol, especially 1.0 to 100 mol per isopropylcyclohexylamide and bromomagnesium diisopro mol of the diol compound (7). The base itself may also be pylamide. In the event where compound (8-1) and/or (8-2) used as a Solvent. is Synthesized in the first Step using a base, it can be further 0132 Suitable solvents include ethers such as tetrahy converted to compound (5) without any additional measure. drofuran, diethyl ether and di-n-butyl ether; chlorinated An appropriate amount of the base used is 0.9 to 100 mol, organic Solvents Such as methylene chloride and chloroform; especially 1.0 to 100 mol per mol of the compound (8-1) hydrocarbons Such as n-hexane, n-heptane, benzene, tolu and/or (8–2) having an eliminatable group. ene, Xylene and cumene; and aprotic polar Solvents Such as 0.138 Suitable solvents include water, ethers such as dimethyl sulfoxide and N,N-dimethylforamide. Depending tetrahydrofuran, diethyl ether, di-n-butyl ether and 1,4- on reaction conditions, a choice may be made among these dioxane, hydrocarbons Such as n-hexane, n-heptane, ben Solvents and mixtures thereof. Zene, toluene, Xylene and cumene, alcohols Such as metha 0133. The reaction temperature and time largely vary nol, ethanol, isopropyl alcohol and tert-butyl alcohol; and with reagents and conditions. In one example wherein aprotic polar solvents such as dimethyl sulfoxide and N,N- US 2002/0197559 A1 Dec. 26, 2002 dimethylforamide. Depending on reaction conditions, a O155 Herein, R', R', and R' independently rep choice may be made among these Solvents and mixtures resent Straight, branched or cyclic alkyl, alkenyl, oxoalkyl or thereof. The base itself may be used as the solvent. OXoalkenyl groups of 1 to 12 carbon atoms, aryl groups of 0.139. The reaction temperature and time largely vary 6 to 20 carbon atoms, or aralkyl or aryloxoalkyl groups of with reagents and conditions. In one example wherein 7 to 12 carbon atoms, wherein Some or all of the hydrogen cyclization reaction is performed under two-layer conditions atoms may be replaced by alkoxy or other groups. Also, using an aqueous Sodium hydroxide Solution and toluene, a and R', taken together, may form a ring. R'' and temperature in the range of room temperature to 100 C., each are alkylene groups of 1 to 6 carbon atoms when desirably 50 to 100° C. is preferred for the quick completion they form a ring. K is a non-nucleophilic counter ion. of reaction. The reaction time is desirably determined by 0156 R', R', and R' may be the same or differ monitoring the reaction until the completion by gas chro ent and are illustrated below. Exemplary alkyl groups matography (GC) or Silica gel thin-layer chromatography include methyl, ethyl, propyl, isopropyl, n-butyl, Sec-butyl, (TLC) because higher yields are expectable. The reaction tert-butyl, pentyl, hexyl, heptyl, octyl, cyclopentyl, cyclo time is usually about 1 to about 60 hours. hexyl, cycloheptyl, cyclopropylmethyl, 4-methylcyclo hexyl, cyclohexylmethyl, norbornyl, and adamantyl. Exem 0140 From the reaction mixture, the end tetrahydrofuran plary alkenyl groups include Vinyl, allyl, propenyl, butenyl, compound (5) is obtained by a conventional aqueous work hexenyl, and cyclohexenyl. Exemplary oxoalkyl groups up step. If necessary, the compound (5) is purified by any include 2-oxocyclopentyl and 2-oxocyclohexyl as well as conventional technique Such as distillation, chromatography 2-oxopropyl, 2-cyclopentyl-2-oxoethyl, 2-cyclohexyl-2- or recrystallization. oxoethyl, and 2-(4-methylcyclohexyl)-2-oxoethyl. Exem 0141 Resist Composition plary aryl groups include phenyl and naphthyl, alkoxyphe nyl groupS Such as p-methoxyphenyl, m-methoxyphenyl, 0142. Since the polymer of the invention is useful as the O-methoxyphenyl, ethoxyphenyl, p-tert-butoxyphenyl, and base resin of a resist composition, the other aspect of the m-tert-butoxyphenyl; alkylphenyl groupS. Such as 2-meth invention provides a resist composition, especially a chemi ylphenyl, 3-methylphenyl, 4-methylphenyl, ethylphenyl, cally amplified positive resist composition, comprising the 4-tert-butylphenyl, 4-butylphenyl, and dimethylphenyl; polymer. Typically, the resist composition contains the poly alkylnaphthyl groups Such as methylnaphthyl and ethyl mer, a photoacid generator, and an organic Solvent, and other naphthyl; alkoxynaphthyl groups Such as methoxynaphthyl optional components. and ethoxynaphthyl, dialkylnaphthyl groupS. Such as dim 0143 Photoacid Generator ethylnaphthyl and diethylnaphthyl; and dialkoxynaphthyl groupS Such as dimethoxynaphthyl and diethoxynaphthyl. 0144. The photoacid generator is a compound capable of Exemplary aralkyl groups include benzyl, phenylethyl, and generating an acid upon exposure to high energy radiation or phenethyl. Exemplary aryloxoalkyl groups are 2-aryl-2- electron beams and includes the following: oxoethyl groups Such as 2-phenyl-2-oxoethyl, 2-(1-naph 0145 (i) onium salts of the formula (P1a-1), (P1a-2) or thyl)-2-oxoethyl, and 2-(2-naphthyl)-2-oxoethyl. Examples (P1b), of the non-nucleophilic counter ion represented by K include halide ions Such as chloride and bromide ions, 0146 (ii) diazomethane derivatives of the formula fluoroalkylsulfonate ions Such as triflate, 1,1,1-trifluoroet (P2), haneSulfonate, and nonafluorobutane-Sulfonate, arylsul fonate ions Such as tosylate, benzeneSulfonate, 4-fluoroben 0147 (iii) glyoxime derivatives of the formula (P3), ZeneSulfonate, and 1,2,3,4,5-pentafluorobenzeneSulfonate, 0148 (iv) bisSulfone derivatives of the formula (P4), and alkylsulfonate ions Such as meSylate and butane Sulfonate. 0149 (v) sulfonic acid esters of N-hydroxyimide com pounds of the formula (P5), P1b. 0150 (vi) B-ketosulfonic acid derivatives, R102a R102b 0151 (vii) disulfone derivatives, R10a-St-R103 St-R104b K K 0152 (viii) nitrobenzylsulfonate derivatives, and 0153 (ix) sulfonate derivatives. O157 Herein, R'' and R' independently represent Straight, branched or cyclic alkyl groups of 1 to 8 carbon 0154) These photoacid generators are described in detail. atoms. R' represents a straight, branched or cyclic alky (i) Onium salts of formula (P1a-1), (Pla-2) or (P1b): lene groups of 1 to 10 carbon atoms. R'' and R' independently represent 2-oxoalkyl groups of 3 to 7 carbon atoms. K is a non-nucleophilic counter ion. 0158 Illustrative of the groups represented by R'' and are methyl, ethyl, propyl, isopropyl, n-butyl, Sec butyl, tert-butyl, pentyl, hexyl, heptyl, octyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, and cyclohexylmethyl. Illustrative of the groups represented by R" are methylene, ethylene, propylene, butylene, penty lene, hexylene, heptylene, octylene, nonylene, 1,4-cyclo US 2002/0197559 A1 Dec. 26, 2002 heXylene, 1,2-cyclohexylene, 1,3-cyclopentylene, 1,4-cy 0166 (iv) Bissulfone Derivatives of Formula (P4) clooctylene, and 1,4-cyclohexanedimethylene. Illustrative of the groups represented by R 104a and R'' are 2-oxopro P4 pyl, 2-oxocyclopentyl, 2-oxocyclohexyl, and 2-oxocyclo O O heptyl. Illustrative examples of the counter ion represented | by K are the same as exemplified for formulae (P1a-1) and R101a-S-CH-S-R101b (P1a-2). O O 0159 (ii) Diazomethane Derivatives of Formula (P2) 0167 Herein, R'' and R'' are as defined above. P2 N 0168 (v) Sulfonic Acid Esters of N-hydroxyimide | Compounds of Formula (P5) R105-SO-Ö-SO-R106

P5 0160 Herein, R'' and R' independently represent O C Straight, branched or cyclic alkyl or halogenated alkyl / N groups of 1 to 12 carbon atoms, aryl or halogenated aryl R N-o-so-R" groups of 6 to 20 carbon atoms, or aralkyl groups of 7 to 12 C carbon atoms. O 0161) Of the groups represented by R'' and R', exem plary alkyl groups include methyl, ethyl, propyl, isopropyl, 0169. Herein, R' is an arylene group of 6 to 10 carbon n-butyl, Sec-butyl, tert-butyl, pentyl, hexyl, heptyl, octyl, atoms, alkylene group of 1 to 6 carbon atoms, or alkenylene amyl, cyclopentyl, cyclohexyl, cycloheptyl, norbornyl, and group of 2 to 6 carbon atoms wherein Some or all of the adamantyl. Exemplary halogenated alkyl groups include hydrogen atoms may be replaced by Straight or branched trifluoromethyl, 1,1,1-trifluoroethyl, 1,1,1-trichloroethyl, alkyl or alkoxy groups of 1 to 4 carbon atoms, nitro, acetyl, and nonafluorobutyl. Exemplary aryl groups include phenyl; or phenyl groups. R' is a straight, branched or cyclic alkyl alkoxyphenyl groups Such as p-methoxyphenyl, m-methoX group of 1 to 8 carbon atoms, alkenyl, alkoxyalkyl, phenyl yphenyl, O-methoxyphenyl, ethoxyphenyl, p-tert-butox or naphthyl group wherein Some or all of the hydrogen yphenyl, and m-tert-butoxyphenyl; and alkylphenyl groups atoms may be replaced by alkyl or alkoxy groups of 1 to 4 Such as 2-methylphenyl, 3-methylphenyl, 4-methylphenyl, carbon atoms, phenyl groups (which may have Substituted ethylphenyl, 4-tert-butylphenyl, 4-butylphenyl, and dimeth thereon an alkyl or alkoxy of 1 to 4 carbon atoms, nitro, or ylphenyl. acetyl group), hetero-aromatic groups of 3 to 5 carbon atoms, or chlorine or fluorine atoms. 0162 Exemplary halogenated aryl groups include fluo 0170 Of the groups represented by R', exemplary rophenyl, chlorophenyl, and 1,2,3,4,5-pentafluorophenyl. arylene groups include 1,2-phenylene and 1,8-naphthylene; Exemplary aralkyl groups include benzyl and phenethyl. exemplary alkylene groups include methylene, ethylene, trimethylene, tetramethylene, phenylethylene, and norbor 0163 (iii) Glyoxime Derivatives of Formula (P3) nane-2,3-diyl; and exemplary alkenylene groups include 1,2-Vinylene, 1-phenyl-1,2-vinylene, and 5-norbornene-2,3- diyl. Of the groups represented by R', exemplary alkyl P3 groups are as exemplified for R' to R', exemplary R 108 R109 alkenyl groups include Vinyl, 1-propenyl, allyl, 1-butenyl, R107-SO-O-N=C-C=N-O-SO-R107 3-butenyl, isoprenyl, 1-pentenyl, 3-pentenyl, 4-pentenyl, dimethylallyl, 1-hexenyl, 3-hexenyl, 5-hexenyl, 1-heptenyl, 3-heptenyl, 6-heptenyl, and 7-octenyl; and exemplary 0164. Herein, R', R', and R' independently repre alkoxyalkyl groups include methoxymethyl, ethoxymethyl, Sent Straight, branched or cyclic alkyl or halogenated alkyl propoxymethyl, butoxymethyl, pentyloxymethyl, hexy groups of 1 to 12 carbon atoms, aryl or halogenated aryl loxymethyl, heptyloxymethyl, methoxyethyl, ethoxyethyl, propoxyethyl, butoxyethyl, pentyloxyethyl, hexyloxyethyl, groups of 6 to 20 carbon atoms, or aralkyl groups of 7 to 12 methoxypropyl, ethoxypropyl, propoxypropyl, butoxypro carbon atoms. Also, R'' and R', taken together, may form pyl, methoxybutyl, ethoxybutyl, propoxybutyl, methoxy a ring. R'' and R' each are straight or branched alkylene pentyl, ethoxypentyl, methoxyhexyl, and methoxyheptyl. groups of 1 to 6 carbon atoms when they form a ring. 0171 Of the substituents on these groups, the alkyl 0.165 Illustrative examples of the alkyl, halogenated groups of 1 to 4 carbon atoms include methyl, ethyl, propyl, alkyl, aryl, halogenated aryl, and aralkyl groups represented isopropyl, n-butyl, isobutyl and tert-butyl, the alkoxy groups by R97, R', and R'' are the same as exemplified for R' of 1 to 4 carbon atoms include methoxy, ethoxy, propoxy, and R". Examples of the alkylene groups represented by isopropoxy, n-butoxy, isobutoxy, and tert-butoxy; the phenyl R and R' include methylene, ethylene, propylene, buty groups which may have Substituted thereon an alkyl or lene, and hexylene. alkoxy of 1 to 4 carbon atoms, nitro, or acetyl group include US 2002/0197559 A1 Dec. 26, 2002 20 phenyl, tolyl, p-tert-butoxyphenyl, p-acetylphenyl and p-ni lyoxime, bis-O-(n-butanesulfonyl)-2,3-pentane trophenyl; the hetero-aromatic groups of 3 to 5 carbon atoms dioneglyoxime, bis-O-(n-butanesulfonyl)-2-methyl include pyridyl and furyl. 3,4-pentanedioneglyoxime, bis-O-(methaneSulfo 0172 Illustrative examples of the photoacid generator nyl)-O-dimethylglyoxime, bis-O-(trifluoromethane include: Sulfonyl)-O-dimethylglyoxime, bis-O-(1,1,1- trifluoroethaneSulfonyl)-O-dimethylglyoxime, bis 0173 onium salts such as diphenyliodonium trifluo O-(tert-butanesulfonyl)-O-dimethylglyoxime, bis-O- romethaneSulfonate, (p-tert-butoxyphenyl)phenyli (perfluorooctanesulfonyl)-O-dimethylglyoxime, bis odonium trifluoromethaneSulfonate, diphenyliodo O-(cyclohexanesulfonyl)-O-dimethylglyoxime, bis nium p-tolueneSulfonate, (p-tert O-(benzenesulfonyl)-O-dimethylglyoxime, bis-O- butoxyphenyl)phenyliodonium p-toluenesulfonate, (p-fluorobenzenesulfonyl)-O-dimethylglyoxime, triphenylsulfonium trifluoromethaneSulfonate, bis-O-(p-tert-butylbenzenesulfonyl)-O-dimethylgly (p-tert-butoxyphenyl)diphenylsulfonium trifluo Oxime, bis-O-(Xylenesulfonyl)-O-dimethylglyoxime, romethaneSulfonate, bis(p-tert-butoxyphenyl)phe nylsulfonium trifluoromethaneSulfonate, tris(p-tert and Ibis-O-(camphorSulfonyl)-O-dimethylglyoxime; butoxyphenyl)sulfonium trifluoromethaneSulfonate, 0176 bisSulfone derivatives such as bisnaphthylsul triphenylsulfonium p-toluenesulfonate, (p-tert-bu fonylmethane, bistrifluoromethylsulfonylmethane, toxyphenyl)diphenylsulfonium p-toluenesulfonate, bismethylsulfonylmethane, bisethylsulfonyl bis(p-tert-butoxyphenyl)phenylsulfonium p-toluene methane, bispropylsulfonylmethane, bisisopropyl Sulfonate, tris(p-tert-butoxyphenyl)sulfonium Sulfonylmethane, bis-p-toluenesulfonylmethane, and p-toluenesulfonate, triphenylsulfonium nonafluo bisbenzeneSulfonylmethane; robutaneSulfonate, triphenylsulfonium butane sulfonate, trimethylsulfonium trifluoromethane 0177 C-ketosulfone derivatives such as 2-cyclohexyl Sulfonate, trimethylsulfonium p-toluenesulfonate, carbonyl -2-(p-toluenesulfonyl)propane and 2-isopropyl cyclohexylmethyl(2-oxocyclohexyl)sulfonium trif carbonyl-2-(p-toluenesulfonyl)propane; luoromethaneSulfonate, cyclohexylmethyl(2-oxocy clohexyl)sulfonium p-toluenesulfonate, dimeth 0.178 disulfone derivatives such as diphenyl disul ylphenylsulfonium trifluoromethaneSulfonate, fone and dicyclohexyl disulfone, dimethylphenylsulfonium p-toluenesulfonate, dicy clohexylphenylsulfonium trifluoromethaneSulfonate, 0179 nitrobenzylsulfonate derivatives such as 2,6- dicyclohexylphenylsulfonium p-toluenesulfonate, dinitrobenzyl p-toluenesulfonate and 2,4-dinitroben trinaphthyl-Sulfonium trifluoromethaneSulfonate, Zyl p-toluenesulfonate; cyclohexylmethyl(2-oxocyclohexyl)sulfonium trif luoromethaneSulfonate, (2-norbornyl)methyl(2-oxo 0180 sulfonic acid ester derivatives such as 1,2,3- cyclohexyl)sulfonium trifluoromethaneSulfonate, tris-(methaneSulfonyloxy)benzene, 1,2,3-tris(trifluo ethylenebismethyl(2-oxocyclopentyl)-Sulfonium romethaneSulfonyloxy)benzene, and 1,2,3-tris(p- trifluoromethaneSulfonate, and 1,2'-naphthylcarbo toluenesulfonyloxy)benzene, and nylmethyltetrahydrothiophenium triflate; 0181 Sulfonic acid esters of N-hydroxyimides such 0174 diazomethane derivatives such as bis(benze as N-hydroxysuccinimide methanesulfonate, N-hy neSulfonyl)diazomethane, bis(p-toluenesulfonyl)dia droxySuccinimide trifluoromethaneSulfonate, N-hy Zomethane, bis(Xylenesulfonyl)diazomethane, bis droxySuccinimide ethaneSulfonate, N-hydroxySuc (cyclohexylsulfonyl)diazomethane, cinimide 1-propanesulfonate, N-hydroxy bis(cyclopentylsulfonyl)diazomethane, bis(n-butyl Succinimide 2-propanesulfonate, N-hydroxySuccin sulfonyl)diazomethane, bis(isobutylsulfonyl)diaz imide 1-pentaneSulfonate, N-hydroxySuccinimide omethane, bis(Sec-butylsulfonyl)diazomethane, 1-octaneSulfonate, N-hydroxySuccinimide p-tolu bis(n-propylsulfonyl)diazomethane, bis(isopropyl eneSulfonate, N-hydroxySuccinimide p-methoxy sulfonyl)diazomethane, bis(tert-butylsulfonyl)diaz benzeneSulfonate, N-hydroxySuccinimide 2-chloro omethane, bis(n-amylsulfonyl)diazomethane, bis(i- ethaneSulfonate, N-hydroxysuccinimide Soamylsulfonyl)diazomethane, bis(Sec benzeneSulfonate, N-hydroxySuccinimide 2,4,6-tri amylsulfonyl)diazomethane, bis(tert-amylsulfonyl) methylbenzeneSulfonate, N-hydroxysuccinimide diazomethane, 1-cyclohexylsulfonyl-1-(tert-butyl 1-naphthaleneSulfonate, N-hydroxysuccinimide Sulfonyl)diazomethane, 1-cyclohexylsulfonyl-1- 2-naphthaleneSulfonate, N-hydroxy-2-phenylsuccin (tert-amylsulfonyl)diazomethane, and 1-tert-amyl imide methanesulfonate, N-hydroxymaleimide sulfonyl-1-(tert-butylsulfonyl)diazomethane; methaneSulfonate, N-hydroxymaleimide ethane-Sul fonate, N-hydroxy-2-phenylmaleimide methane 0175 glyoxime derivatives such as bis-O-(p-tolu Sulfonate, N-hydroxyglutarimide methaneSulfonate, ene-Sulfonyl)-O-dimethylglyoxime, bis-O-(p-tolu N-hydroxyglutarimide benzenesulfonate, N-hydrox enesulfonyl)-O-diphenylglyoxime, bis-O-(p-tolu yphthalimide methanesulfonate, N-hydroxyphthal enesulfonyl)-O-dicyclohexylglyoxime, bis-O-(p- imide benzenesulfonate, N-hydroxyphthalimide tri toluenesulfonyl)-2,3-pentanedioneglyoxime, bis-O- fluoromethaneSulfonate, N-hydroxyphthalimide (p-toluenesulfonyl)-2-methyl-3,4-pentanedione p-toluenesulfonate, N-hydroxynaphthalimide meth glyoxime, bis-O-(n-butanesulfonyl)-O-dimethylgly aneSulfonate, N-hydroxynaphthalimide benzene Oxime, bis-O-(n-butanesulfonyl)-O-diphenylgly sulfonate, N-hydroxy-5-norbornene-2,3-dicarboxy Oxime, bis-O-(n-butanesulfonyl)-O-dicyclohexylg imide methanesulfonate, N-hydroxy-5-norbornene US 2002/0197559 A1 Dec. 26, 2002

2,3-dicarboxyimide trifluoromethaneSulfonate, and ypropionate, tert-butyl acetate, tert-butyl propionate, and N-hydroxy-5-norbornene-2,3-dicarboxyimide propylene glycol mono-tert-butyl ether acetate; and lactones p-toluenesulfonate. Such as Y-butyrolactone. These Solvents may be used alone 0182 Preferred among these photoacid generators are or in combinations of two or more thereof. Of the above onium Salts. Such as triphenylsulfonium trifluoromethane organic Solvents, it is recommended to use diethylene glycol Sulfonate, (p-tert-butoxyphenyl)diphenylsulfonium trifluo dimethyl ether and 1-ethoxy-2-propanol because the photo romethaneSulfonate, tris(p-tert-butoxyphenyl)sulfonium tri acid generator is most Soluble therein, propylene glycol fluoromethaneSulfonate, triphenylsulfonium monomethyl ether acetate because it is a safe Solvent, or a p-tolueneSulfonate, (p-tert-butoxyphenyl)diphenylsulfo mixture thereof. nium p-toluenesulfonate, tris(p-tert-butoxyphenyl)sulfo nium p-toluenesulfonate, trinaphthylsulfonium trifluo 0187. An appropriate amount of the organic solvent used romethaneSulfonate, cyclohexylmethyl(2-oxocyclohexyl) is about 200 to 1,000 parts, especially about 400 to 800 parts sulfonium trifluoromethanesulfonate, (2-norbornyl)m- by weight per 100 parts by weight of the base resin. ethyl(2-oxocylohexyl)sulfonium trifluoromethanesulfonate, and 1,2'-naphthylcarbonylmethyltetrahydrothiophenium tri 0188 Other Polymer flate; diazomethane derivatives Such as bis(benzenesulfo nyl)diazomethane, bis(p-toluenesulfonyl)diazomethane, bis 0189 To the resist composition of the invention, another (cyclohexylsulfonyl)diazomethane, bis(n-butylsulfonyl) polymer other than the inventive polymer comprising recur diazomethane, bis(isobutylsulfonyl)diazomethane, bis(Sec ring units of formula (1-1) or (1-2) may also be added. The butylsulfonyl)diazomethane bis(n-propylsulfonyl)diaz other polymers that can be added to the resist composition omethane, bis(isopropylsulfonyl)diazomethane, and bis are, for example, those polymers comprising units of the (tert-butylsulfonyl)diazomethane; glyoxime derivatives Such as bis-O-(p-toluenesulfonyl)-O-dimethylglyoxime and following formula (R1) and/or (R2) and having a weight bis-O-(n-butanesulfonyl)-O-dimethylglyoxime; bisSulfone average molecular weight of about 1,000 to about 500,000, derivatives Such as bisnaphthylsulfonylmethane; and Sul especially about 5,000 to about 100,000 although the other fonic acid esters of N-hydroxyimide compounds Such as polymers are not limited thereto. N-hydroxysuccinimide methanesulfonate, N-hydroxysuc cinimide trifluoromethaneSulfonate, N-hydroxySuccinimide 1-propanesulfonate, N-hydroxySuccinimide 2-propane (R1) Sulfonate, N-hydroxySuccinimide 1-pentaneSulfonate, N-hy R002 R001 R002 R001 R002 R001 droxySuccinimide p-toluenesulfonate, N-hydroxynaphthal imide methaneSulfonate, and N-hydroxynaphthalimide (-)-(–) (-)-(–) (-)-(–) benzeneSulfonate. H COR004 H COR009 H. COR014 0183 These photoacid generators may be used singly or in combinations of two or more thereof. Onium salts are effective for improving rectangularity, while diazomethane ( )a2 ( )b2. derivatives and glyoxime derivatives are effective for reduc ing Standing waves. The combination of an onium Salt with R002 R001 a diazomethane or a glyoxime derivative allows for fine (-)-(–) adjustment of the profile. H 0184 The photoacid generator is added in an amount of 2 * R008 R010 K-RO13 0.1 to 15 parts, and especially 0.5 to 8 parts by weight, per R007 R011 R012 100 parts by weight of the base resin (all parts are by weight, ( )d2 hereinafter). Less than 0.1 part of the photoacid generator would provide a poor Sensitivity whereas more than 15 parts of the photoacid generator would adversely affect transpar ency and resolution. 0185 Organic Solvent R002 S-R001 0186 The organic solvent used herein may be any H COR015 organic ; Solvent in which the base resin, photoacid generator, and other components are Soluble. Illustrative, non-limiting, examples of the organic Solvent include ketones Such as cyclohexanone and methyl-2-n-amylketone; (R2) alcohols such as 3-methoxybutanol, 3-methyl-3-methoxybu ( )b3' tanol, 1-methoxy-2-propanol, and 1-ethoxy-2-propanol; X etherS Such as propylene glycol monomethyl ether, ethylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monoethyl ether, propylene glycol dimethyl ether, and diethylene glycol dimethyl ether; esterS Such as propylene glycol monomethyl ether acetate, propylene gly R010 R013 col monoethyl ether acetate, ethyl lactate, ethyl pyruvate, R011 R012 butyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoX US 2002/0197559 A1 Dec. 26, 2002 22

containing a polycyclic hydrocarbon group. R' is an acid

-continued labile group. R' is hydrogen or methyl. R'7 is a straight, branched or cyclic alkyl group of 1 to 8 carbon atoms. X is CH2 or an oxygen atom. Letter k" is equal to 0 or 1; a1, a2, a3', b1", b2, b3', c1", c2", c3', d1,d2, d3', and e' are numbers from 0 to less than 1, satisfying a 1'--a2+a3'+b1"+b2+b3'+ c1"+c2"+c3'+d1'--d2+d3+e'=1; f,g,h', i', and j' are numbers from 0 to less than 1, Satisfying fg'+h1+i'+'=1; x, y and Zeach are an integer of 0 to 3, Satisfying 1sX'+y'+Z2S5 and 1sy'+z's3. 0191 Exemplary groups of these R's are as exemplified above. 0192 The inventive polymer (comprising recurring units of formula (1-1) or (1-2)) and the other polymer are pref erably blended in a weight ratio from 100:0 to 10:90, more preferably from 100:0 to 20:80. If the blend ratio of the inventive polymer is below this range, the resist composition would become poor in Some of the desired properties. The properties of the resist composition can be adjusted by properly changing the blend ratio of the inventive polymer. 0193 The other polymer is not limited to one type and a mixture of two or more other polymers may be added. The use of plural polymerS allows for easy adjustment of resist properties. 0194 Dissolution Regulator 0.195 To the resist composition, a dissolution regulator 0190. Herein, R' is hydrogen, methyl or CHCo-R' may be added. The dissolution regulator is a compound R' is hydrogen, methyl or COR. R' is a straight, having on the molecule at least two phenolic hydroxyl branched or cyclic alkyl group of 1 to 15 carbon atoms. R' groups, in which an average of from 0 to 100 molt of all the is hydrogen or a monovalent hydrocarbon group of 1 to 15 hydrogen atoms on the phenolic hydroxyl groups are carbon atoms having a carboxyl or hydroxyl group. At least replaced with acid labile groups or a compound having on one of R' to R' represents a monovalent hydrocarbon the molecule at least one carboxyl group, in which an group of 1 to 15 carbon atoms having a carboxyl or hydroxyl average of 50 to 100 mol% of all the hydrogen atoms on the group while the remaining R's independently represent carboxyl groups are replaced with acid labile groups, both hydrogen or a Straight, branched or cyclic alkyl group of 1 the compounds having an average molecular weight within to 15 carbon atoms. Alternatively, R' to R', taken a range of 100 to 1,000, and preferably 150 to 800. together, may form a ring, and in that event, at least one of R' to R' is a divalent hydrocarbon group of 1 to 15 0196. The degree of Substitution of the hydrogen atoms carbon atoms having a carboxyl or hydroxyl group, while on the phenolic hydroxyl groups with acid labile groupS is the remaining R's are independently Single bonds or on average at least Omol %, and preferably at least 30 molt, Straight, branched or cyclic alkylene groups of 1 to 15 of all the phenolic hydroxyl groups. The upper limit is 100 carbon atoms. R' is a monovalent hydrocarbon group of 2 molt, and preferably 80 mol%. The degree of substitution of to 15 carbon atoms containing at least one partial Structure the hydrogen atoms on the carboxyl groups with acid labile Selected from among ether, aldehyde, ketone, ester, carbon groups is on average at least 50 mol %, and preferably at ate, acid anhydride, amide and imide. At least one of R' to least 70 mol %, of all the carboxyl groups, with the upper R" is a monovalent hydrocarbon group of 2 to 15 carbon limit being 100 mol%. atoms containing at least one partial Structure Selected from among ether, aldehyde, ketone, ester, carbonate, acid anhy 0197) Preferable examples of such compounds having dride, amide and imide, while the remaining R's are inde two or more phenolic hydroxyl groups or compounds having pendently hydrogen or Straight, branched or cyclic alkyl at least one carboxyl group include those of formulas (D1) groups of 1 to 15 carbon atoms. R' to R', taken together, to (D14) below. may form a ring, and in that event, at least one of R010 to R is a divalent hydrocarbon group of 1 to 15 carbon atoms containing at least one partial Structure Selected from among ether, aldehyde, ketone, ester, carbonate, acid anhydride, amide and imide, while the remaining R's are independently Single bonds or Straight, branched or cyclic alkylene groups of 1 to 15 carbon atoms. R'' is a polycyclic hydrocarbon group having 7 to 15 carbon atoms or an alkyl group US 2002/0197559 A1 Dec. 26, 2002 23

-continued -continued W (OH)OH) D10 / X SC (OH), = R201 N A4Y-X R201 R201 D11 V- (OH) / SCS. D3 (OH), rip= R201 R2014 44 R201 D12 S4COOH (OH)4 R202 oy-(OH). M M 2 Ravi,201 1& / R203 \ 5S,201Rav D13 (CH2)COOH (OH)4 R202 oy-(OH). R2011KM / \ ŽSR201A. 21 D14 COOH s S ) R201 (OH)

(OH) NC (R204) y- (OH) R2011KV / \ A.C R201 (OH) SC / S (OH) R208 R208 M R2011S / S R201 0198 In these formulas, R'' and R' are each hydrogen (R205) or a straight or branched alkyl or alkenyl of 1 to 8 carbon atoms; R' is hydrogen, a straight or branched alkyl or R206 / o alkenyl of 1 to 8 carbon atoms, or -(R'7)-COOH; R' is-(CH) - (where i=2 to 10), an arylene of 6 to 10 carbon = 7 R. atoms, carbonyl, Sulfonyl, an oxygen atom, or a Sulfur atom; R’ is an alkylene of 1 to 10 carbon atoms, an arylene of 6 to 10 carbon atoms, carbonyl, Sulfonyl, an oxygen atom, or a sulfur atom; R is hydrogen, a straight or branched alkyl or alkenyl of 1 to 8 carbon atoms, or a hydroxyl-substituted phenyl or naphthyl; R' is a straight or branched alkylene r of 1 to 10 carbon atoms; R is hydrogen or hydroxyl; the letter j is an integer from 0 to 5; u and h are each 0 or 1; S, 7s), t, S', t', S', and t" are each numbers which Satisfy S+t=8, s'+t'=5, and S"+t"=4, and are Such that each phenyl skeleton has at least one hydroxyl group; and C. is a number Such that 21 C the compounds of formula (D8) or (D9) have a molecular weight of from 100 to 1,000. Šy. 0199. In the above formulas, suitable examples of R' and R' include hydrogen, methyl, ethyl, butyl, propyl, US 2002/0197559 A1 Dec. 26, 2002 24 ethynyl, and cyclohexyl; suitable examples of R' include to 0, 1, 2 or 3, and 2m+n is equal to 2 or 3. Illustrative the same groups as for R'' and R', as well as -COOH examples of these groups are as previously exemplified. and -CHCOOH; suitable examples of R' include eth 0202) The dissolution regulator may be formulated in an ylene, phenylene, carbonyl, Sulfonyl, oxygen, and Sulfur, amount of 0 to 50 parts, preferably 0 to 40 parts, and more suitable examples of R' include methylene as well as the preferably 0 to 30 parts, per 100 parts of the base resin, and same groups as for R'; and suitable examples of R' may be used singly or as a mixture of two or more thereof. include hydrogen, methyl, ethyl, butyl, propyl, ethynyl, The use of more than 50 parts would lead to slimming of the cyclohexyl, and hydroxyl-Substituted phenyl or naphthyl. patterned film, and thus a decline in resolution. 0200 Exemplary acid labile groups on the dissolution regulator include groups of the following general formulae 0203 The dissolution regulator can be synthesized by (L1) to (L4), tertiary alkyl groups of 4 to 20 carbon atoms, introducing acid labile groups into a compound having trialkylsilyl groups in which each of the alkyls has 1 to 6 phenolic hydroxyl or carboxyl groups in accordance with an carbon atoms, and OXO alkyl groups of 4 to 20 carbon atoms. organic chemical formulation. 0204 Basic Compound

L1 0205. In the resist composition of the invention, a basic RLO1 ( ) compound may be blended. A Suitable basic compound used herein is a compound capable of Suppressing the rate of – ORL03 diffusion when the acid generated by the photoacid genera lo tor diffuses within the resist film. The inclusion of this type (L.2) of basic compound holds down the rate of acid diffusion O within the resist film, resulting in better resolution. In addition, it Suppresses changes in Sensitivity following (CH3)-6-ORL04 exposure, thus reducing Substrate and environment depen (L3) dence, as well as improving the exposure latitude and the RL05 pattern profile. (CH2) 0206 Examples of basic compounds include primary, X)(CHFCH) Secondary, and tertiary aliphatic amines, mixed amines, (L4) aromatic amines, heterocyclic amines, carboxyl group-bear RL13 RL14 ing nitrogenous compounds, Sulfonyl group-bearing nitrog enous compounds, hydroxyl group-bearing nitrogenous compounds, hydroxyphenyl group-bearing nitrogenous compounds, alcoholic nitrogenous compounds, amide derivatives, and imide derivatives. 0207 Examples of suitable primary aliphatic amines include ammonia, methylamine, ethylamine, n-propy lamine, isopropylamine, n-butylamine, iso-butylamine, Sec butylamine, tert-butylamine, pentylamine, tert-amylamine, 0201) In these formulas, and are each hydrogen cyclopentylamine, hexylamine, cyclohexylamine, hepty or a straight, branched or cyclic alkyl having 1 to 18 carbon lamine, octylamine, nonylamine, decylamine, dodecy atoms; and R' is a monovalent hydrocarbon group of 1 to lamine, cetylamine, methylene-diamine, ethylenediamine, 18 carbon atoms which may contain a heteroatom (e.g., and tetraethylenepentamine. Examples of Suitable Secondary oxygen). A pair of R'' and R', a pair of R'' and R', aliphatic amines include dimethylamine, diethylamine, di-n- or a pair of R'' and R' may together form a ring, with the propylamine, di-iso-propylamine, di-n-butylamine, di-iso proviso that , and are each a Straight or butylamine, di-Sec-butylamine, dipentylamine, dicyclopen branched alkylene of 1 to 18 carbon atoms when they form tylamine, dihexylamine, dicyclohexylamine, diheptylamine, a ring. R'' is a tertiary alkyl group of 4 to 20 carbon atoms, dioctylamine, dinonylamine, didecylamine, didodecy a trialkysilyl group in which each of the alkyls has 1 to 6 lamine, dicetylamine, N,N-dimethyl-methylenediamine, carbon atoms, an oxoalkyl group of 4 to 20 carbon atoms, or N,N-dimethylethylenediamine, and N,N-dimethyltetraethyl a group of the formula (L1). R' is a monovalent hydro enepentamine. Examples of Suitable tertiary aliphatic carbon group of 1 to 8 carbon atoms which may contain a amines include trimethylamine, triethylamine, tri-n-propy hetero atom or a Substituted or unsubstituted aryl group of 6 lamine, tri-iso-propylamine, tri-n-butylamine, tri-iso-buty to 20 carbon atoms. R' is a monovalent hydrocarbon lamine, tri-Sec-butylamine, tripentylamine, tricyclopenty group of 1 to 8 carbon atoms which may contain a hetero lamine, trihexylamine, tricyclohexylamine, triheptylamine, atom or a substituted or unsubstituted aryl group of 6 to 20 carbon atoms. R'7 to R' independently represent hydro trioctylamine, trinonylamine, tridecylamine, tridodecy gen or monovalent hydrocarbon groups of 1 to 15 carbon lamine, tricetylamine, N,N,N',N'-tetramethylmethylenedi atoms which may contain a hetero atom. Alternatively, R' amine, N.N,N',N'-tetramethylethylenediamine, and N,N,N', to R', taken together, may form a ring. Each of R" to N'-tetramethyltetraethylenepentamine. represents a divalent C-C hydrocarbon group which 0208 Examples of suitable mixed amines include dim may contain a hetero atom, when they form a ring. Two of ethylethylamine, methylethylpropylamine, benzylamine, R' to R' which are attached to adjoining carbon atoms phenethylamine, and benzyldimethylamine. Examples of may bond together directly to form a double bond. Letter y Suitable aromatic and heterocyclic amines include aniline is an integer of 0 to 6. Letter m is equal to 0 or 1, n is equal derivatives (e.g., aniline, N-methylaniline, N-ethylaniline, US 2002/0197559 A1 Dec. 26, 2002

N-propylaniline, N,N-dimethylaniline, 2-methylaniline, Examples of Suitable amide derivatives include formamide, 3-methylaniline, 4-methylaniline, ethylaniline, propyla N-methylformamide, N,N-dimethylformamide, acetamide, niline, trimethylaniline, 2-nitroaniline, 3-nitroaniline, 4-ni N-methylacetamide, N,N-dimethylacetamide, propiona troaniline, 2,4-dinitroaniline, 2,6-dinitroaniline, 3,5-dini mide, and benzamide. Suitable imide derivatives include troaniline, and N,N-dimethylltoluidine), diphenyl(p- phthalimide, Succinimide, and maleimide. tolyl)amine, methyldiphenylamine, triphenylamine, phenylenediamine, naphthylamine, diaminonaphthalene, 0210. In addition, basic compounds of the following pyrrole derivatives (e.g., pyrrole, 2H-pyrrole, 1-methylpyr general formula (B1) may also be included alone or in role, 2,4-dimethylpyrrole, 2,5-dimethylpyrrole, and N-me admixture. thylpyrrole), oxazole derivatives (e.g., oxazole and isoox azole), thiazole derivatives (e.g., thiazole and isothiazole), imidazole derivatives (e.g., imidazole, 4-methylimidazole, 0211. In the formula, n is equal to 1, 2 or 3; Y is and 4-methyl-2-phenylimidazole), pyrazole derivatives, independently hydrogen or a Straight, branched or cyclic furazan derivatives, pyrroline derivatives (e.g., pyrroline and 2-methyl-1-pyrroline), pyrrolidine derivatives (e.g., pyr alkyl group of 1 to 20 carbon atoms which may contain a rolidine, N-methylpyrrolidine, pyrrolidinone, and N-meth hydroxyl group or ether; and X is independently Selected ylpyrrolidone), imidazoline derivatives, imidazolidine from groups of the following general formulas (X1) to (X3), derivatives, pyridine derivatives (e.g., pyridine, methylpy and two or three X's may bond together to form a ring. ridine, ethylpyridine, propylpyridine, butylpyridine, 4-(1- butylpentyl)pyridine, dimethylpyridine, trimethylpyridine, X1 triethylpyridine, phenylpyridine, 3-methyl-2-phenylpyri -R300-O-R301 (X1) dine, 4-tert-butylpyridine, diphenylpyridine, benzylpyri O (X2) dine, methoxypyridine, butoxypyridine, dimethoxypyridine, 1-methyl-2-pyridone, 4-pyrrolidinopyridine, 1-methyl-4- -R302-O-R303- J-Ro, phenylpyridine, 2-(1-ethylpropyl)pyridine, aminopyridine, (X3) and dimethylaminopyridine), pyridazine derivatives, pyri O midine derivatives, pyrazine derivatives, pyrazoline deriva tives, pyrazolidine derivatives, piperidine derivatives, pip erazine derivatives, morpholine derivatives, indole derivatives, isolindole derivatives, 1H-indazole derivatives, indoline derivatives, quinoline derivatives (e.g., quinoline 0212. In the formulas, R', R'' and R'' are indepen and 3-quinolinecarbonitrile), isoquinoline derivatives, cin dently Straight or branched alkylene groups of 1 to 4 carbon noline derivatives, quinazoline derivatives, quinoxaline atoms; R', R'' and R are independently hydrogen, derivatives, phthalazine derivatives, purine derivatives, pte Straight, branched or cyclic alkyl groups of 1 to 20 carbon ridine derivatives, carbazole derivatives, phenanthridine atoms, which may contain at least one hydroxyl group, ether, derivatives, acridine derivatives, phenazine derivatives, ester or lactone ring; and R' is a single bond or a straight 1,10-phenanthroline derivatives, adenine derivatives, or branched alkylene group of 1 to 4 carbon atoms. adenosine derivatives, guanine derivatives, guanosine 0213 Illustrative examples of the compounds of formula derivatives, uracil derivatives, and uridine derivatives. (B1) include tris(2-methoxymethoxyethyl)amine, tris(2-(2- 0209 Examples of suitable carboxyl group-bearing methoxyethoxy)ethylamine, tris(2-(2-methoxyethoxy nitrogenous compounds include aminobenzoic acid, indole methoxy)ethylamine, tris(2-(1-methoxyethoxy) carboxylic acid, and amino acid derivatives (e.g. nicotinic ethylamine, tris(2-(1-ethoxyethoxy)ethylamine, tris(2- acid, alanine, alginine, aspartic acid, glutamic acid, glycine, (1-ethoxypropoxy)ethyl-amine, tris(2-2-(2-hydroxy histidine, isoleucine, glycylleucine, leucine, methionine, ethoxy) ethoxyethylamine, 4,7,13,16.21,24-hexaoxa-1, phenylalanine, threonine, lysine, 3-aminopyrazine-2-car 10-diazabicyclo8.8.8) hexacosane, 4,7,13,18-tetraoxa-1,10 boxylic acid, and methoxyalanine). Examples of Suitable diazabicyclo8.5.5eicosane, 14,10,13-tetraoxa-7,16 Sulfonyl group-bearing nitrogenous compounds include 3-pyridineSulfonic acid and pyridinium p-toluenesulfonate. diazabicyclooctadecane, 1-aza-12-crown-4,1-aza-15 Examples of Suitable hydroxyl group-bearing nitrogenous crown-5,1-aza-18-crown-6, tris(2-formyloxyethyl)amine, compounds, hydroxyphenyl group-bearing nitrogenous tris(2-acetoxyethyl)amine, tris(2-propionyloxyethyl)amine, compounds, and alcoholic nitrogenous compounds include tris(2-butyryloxyethyl)amine, tris(2-isobutyryloxyethy 2-hydroxypyridine, aminocreSol, 2,4-quinolinediol, 3-in l)amine, tris(2-Valeryloxyethyl)amine, tris(2-pivaloyloxy dolemethanol hydrate, monoethanolamine, diethanolamine, ethyl)amine, N,N-bis(2-acetoxy-ethyl)-2-(acetoxyacetoxy) triethanolamine, N-ethyldiethanolamine, N,N-diethyletha ethylamine, tris(2-methoxycarbonyl-oxyethyl)amine, tris(2- nolamine, truisopropanolamine, 2,2'-iminodiethanol, 2-ami tert-butoxycarbonyloxyethyl)amine, tris(2-(2-oxopropoxy) noethanol, 3-amino-1-propanol, 4-amino-1-butanol, 4-(2- ethylamine, tris(2-(methoxycarbonyl-methyl)oxyethyl hydroxyethyl)morpholine, 2-(2-hydroxyethyl)pyridine, amine, tris(2-(tert-butoxycarbonylmethyloxy)ethylamine, 1-(2-hydroxyethyl)piperazine, 1-2-(2-hydroxyethoxy) tris(2-(cyclohexyloxycarbonylmethyloxy)ethylamine, ethyl-piperazine, piperidine ethanol, 1-(2-hydroxyeth tris(2-methoxycarbonylethyl)amine, tris(2-ethoxycarbonyl yl)pyrrolidine, 1-(2-hydroxyethyl)-2-pyrrolidinone, 3-pip ethyl)amine, N,N-bis(2-hydroxyethyl)-2-(methoxycarbon eridino-1,2-propanediol, 3-pyrrolidino-1,2-propanediol, yl)ethylamine, N,N-bis(2-acetoxyethyl)-2-(methoxycarbon 8-hydroxylulolidine, 3-quinuclidinol, 3-tropanol, 1-methyl yl)ethylamine, N,N-bis(2-hydroxyethyl)-2- 2-pyrrolidine ethanol, 1-aziridine ethanol, N-(2-hydroxyeth (ethoxycarbonyl)ethylamine, N,N-bis(2-acetoxyethyl)-2- yl)phthalimide, and N-(2-hydroxyethyl)isonicotinamide. (ethoxycarbonyl)ethylamine, N,N-bis(2-hydroxyethyl)-2-

US 2002/0197559 A1 Dec. 26, 2002 27 cyanoethyl)-3-aminopropiononitrile, diethylamino acetonitrile, N,N-bis(2-hydroxyethyl)aminoacetonitrile, N,N-bis(2-acetoxyethyl)aminoacetonitrile, N,N-bis(2- A1 formyloxyethyl)aminoacetonitrile, N,N-bis(2-methoxyethy l)aminoacetonitrile, N,N-bis(2-(methoxymethoxy)ethyl aminoacetonitrile, methyl N-cyanomethyl-N-(2- methoxyethyl)-3-aminopropionate, methyl N-cyanomethyl N-(2-hydroxyethyl)-3-aminopropionate, methyl N-(2- R102. acetoxyethyl)-N-cyanomethyl-3-aminopropionate, N-cyanomethyl-N-(2-hydroxyethyl)aminoacetonitrile, N-(2-acetoxyethyl)-N-(cyanomethyl)aminoacetonitrile, A2 N-cyanomethyl-N-(2-formyloxyethyl)aminoacetonitrile, R403 N-cyanomethyl-N-(2-methoxyethyl)aminoacetonitrile, (OH)6 N-cyanomethyl-N-2-(methoxymethoxy)ethyl)aminoac M etonitrile, N-cyanomethyl-N-(3-hydroxy-1-propyl)aminoac R*-g402 1& R404 etonitrile, N-(3-acetoxy-1-propyl)-N-(cyanomethyl)ami noacetonitrile, N-cyanomethyl-N-(3-formyloxy-1- propyl)aminoacetonitrile, N,N- A3 bis(cyanomethyl)aminoacetonitrile, R403 1-pyrrolidinepropiononitrile, 1-piperidinepropiononitrile, (OH)6 4-morpholinepropiononitrile, 1-pyrrolidineacetonitrile, M 1-piperidineacetonitrile, 4-morpholineacetonitrile, cyanom R102 K ethyl 3-diethylaminopropionate, cyanomethyl N,N-bis(2- 21 hydroxyethyl)-3-aminopropionate, cyanomethyl N,N-bis(2- Sa acetoxyethyl)-3-aminopropionate, cyanomethyl N,N-bis(2- Sa formyloxyethyl)-3-aminopropionate, cyanomethyl N,N- R402 S-X bis(2-methoxyethyl)-3-aminopropionate, cyanomethyl N,N- A4 bis(2-(methoxymethoxy) ethyl-3-aminopropionate, (OH)6 2-cyanoethyl 3-diethylaminopropionate, 2-cyanoethyl N,N- M ( bis(2-hydroxyethyl)-3-aminopropionate, 2-cyanoethyl N,N- R402 1& / bis(2-acetoxyethyl)-3-aminopropionate, 2-cyanoethyl N,N- bis (2-formyloxyethyl)-3-aminopropionate, 2-cyanoethyl A5 N,N-bis(2-methoxyethyl)-3-aminopropionate, 2-cyanoethyl N,N-bis(2-(methoxymethoxy)ethyl-3-aminopropionate, cyanomethyl 1-pyrrolidinepropionate, cyanomethyl 1-pip eridinepropionate, cyanomethyl 4-morpholinepropionate, 2-cyanoethylN 1-pyrrolidinepropionate, 2-cyanoethyl 1-pi peridinepropionate, and 2-cyanoethyl 4-morpholinepropi Onate. 0220. The basic compound is preferably formulated in an amount of 0.001 to 10 parts, and especially 0.01 to 1 part, per part of the photoacid generator. Less than 0.001 part of the basic compound may fail to achieve the desired effects thereof, while the use of more than 10 parts would result in too low a Sensitivity and resolution. 0221) Other Components 0222. In the resist composition, a compound bearing a =C-COOH group in a molecule may be blended. Exem plary, non-limiting compounds bearing a =C-COOH group include one or more compounds Selected from Groups I and II below. Including this compound improves the PED sta bility of the resist and ameliorates edge roughness on nitride film Substrates. 0223 Group I: 0224 Compounds in which some or all of the hydrogen atoms on the phenolic hydroxyl groups of the compounds of general formulas (A1) to (A10) below have been replaced with-R'-COOH (wherein R' is a straight or branched alkylene of 1 to 10 carbon atoms), and in which the molar ratio C/(C+D) of phenolic hydroxyl groups (C) to =C-COOH groups (D) in the molecule is from 0.1 to 1.0. US 2002/0197559 A1 Dec. 26, 2002 28

-continued -continued A9 A13 / V-(OH)12S. SACOOH (OH)3 O S R402 2 A14 7 21 rl, (CH2)COOH A10 (OH)4

A15

O 2. COOH

0225. In these formulas, R' is hydrogen or methyl; R' and R' are each hydrogen or a straight or branched alkyl or alkenyl of 1 to 8 carbon atoms; R" is hydrogen, a Straight or branched alkyl or alkenyl of 1 to 8 carbon atoms, or a -(R')-COOR group (R' being hydrogen or -R'-COOH); R' is -(CH-)- (whereini is 2 to 10), R412 R412 an arylene of 6 to 10 carbon atoms, carbonyl, Sulfonyl, an oxygen atom, or a sulfur atom; R" is an alkylene of 1 to 10 carbon atoms, an arylene of 6 to 10 carbon atoms, carbonyl, 0228. In these formulas, R', R', and R'' are as Sulfonyl, an oxygen atom, or a Sulfur atom; R" is hydro defined above; R' is hydrogen or hydroxyl; s5 and t5 are gen, a Straight or branched alkyl or alkenyl of 1 to 8 carbon numbers which satisfy S520, t5e0, and S5+t3=5; and h' is atoms, or a hydroxyl-substituted phenyl or naphthyl; R' is equal to 0 or 1. a straight or branched alkylene of 1 to 10 carbon atoms; R' 0229. Illustrative, non-limiting examples of the com is hydrogen, a Straight or branched alkyl or alkenyl of 1 to pound bearing a =C-COOH group include compounds of 8 carbon atoms, or a -R'-COOH group; R'' is a the general formulas AI-1 to AI-14 and AII-1 to AII-10 straight or branched alkylene of 1 to 10 carbon atoms; the below. letter is an integer from 0 to 5; u and h are each 0 or 1, S1, t1, S2, t2, S3, t3, S4, and ta- are each numbers which Satisfy S1+t1=8, S2+t2=5, s3+t3=4, and S4+t4=6, and are Such that AI-1 each phenyl skeleton has at least one hydroxyl group; K is a OR" number such that the compound of formula (A6) may have a weight average molecular weight of 1,000 to 5,000; and 2. is a number Such that the compound of formula (A7) may have a weight average molecular weight of 1,000 to 10,000. AI-2 0226 Group II: CH 0227 Compounds of general formulas (A11) to (A15) ro-K)- OR" below. CH AI-3

A11 th OR" R403 (OH), 3)M { x1M (OH)s fl. R102-8 / R411 \ MSS R40s COOR" AI-4 COOH A12 th fl. CH-COOR" US 2002/0197559 A1 Dec. 26, 2002 29

-continued -continued AI-5 AI-13 OR"

OR" t CH R"O O -() ()- OR"

AI-6 R"O CH CH

AI-14

AI-7 R"O CHCOOR"

AI-8 0230) In the above formulas, R" is hydrogen or a Rose - / OR CHCOOH group such that the CHCOOH group accounts for 10 to 100 mol % of R" in each compound, C. and K are \ / o as defined above. CH2 HC 3 / \ AII-1 =7 OR th to-()--()—onCOOH AII-2 HC ( ) CH to-()--()—onth CH2 fl. CH-COOH HC A-3 ( ) CH t

HC OR" COOH AI-10 AII-4

C th fl. CH-COOH AII-5 OR" AI-11 ()-cisco AII-6

lorsOR" AI-12 to-()-cisco OR" A-7 COOH

OR" C US 2002/0197559 A1 Dec. 26, 2002 30

Surfynol 104E, Surfynol 104H, Surfynol 104A, Surfynol -continued TG, Surfynol PC, Surfynol 440, Surfynol 465, and Surfynol A-8 COOH 485 from Air Products and Chemicals Inc., and Surfynol E1004 from Nisshin Chemical Industry K.K. 0236. The acetylene alcohol derivative is preferably added in an amount of 0.01 to 2% by weight, and more preferably 0.02 to 1% by weight, per 100% by weight of the resist composition. Less than 0.01% by weight would be AII-9 ineffective for improving coating characteristics and shelf CHCOOH stability, whereas more than 2% by weight would result in a resist having a low resolution. 0237) The resist composition of the invention may include optional ingredients, for example, a Surfactant which is commonly used for improving the coating characteristics. AII-10 Optional ingredients may be added in conventional amounts COOH So long as this does not compromise the objects of the CH invention. 0238) Nonionic surfactants are preferred, examples of CH which include perfluoroalkylpolyoxyethylene ethanols, flu orinated alkyl esters, perfluoroalkylamine oxides, perfluo roalkyl EO-addition products, and fluorinated organosilox HO ane compounds. Useful Surfactants are commercially available under the trade names Florade FC-430 and FC-431 from Sumitomo 3M, Ltd., Surflon S-141 and S-145, KH-10, 0231. The compound bearing a =C-COOH group KH-20, KH-30 and KH-40 from Asahi Glass Co., Ltd., within the molecule may be used singly or as combinations Unidyne DS-401, DS-403 and DS-451 from Daikin Industry of two or more thereof. Co., Ltd., Megaface F-8151 from Dai-Nippon Ink & Chemi 0232 The compound bearing a =C-COOH group cals, Inc., and X-70-092 and X-70-093 from Shin-Etsu within the molecule is added in an amount ranging from 0 Chemical Co., Ltd. Preferred Surfactants are Florade FC-430 to 5 parts, preferably 0.1 to 5 parts, more preferably 0.1 to from Sumitomo 3M, Ltd., KH-20 and KH-30 from Asahi 3 parts, further preferably 0.1 to 2 parts, per 100 parts of the Glass Co., Ltd., and X-70-093 from Shin-Etsu Chemical base resin. More than 5 parts of the compound can reduce Co., Ltd. the resolution of the resist composition. 0233. The resist composition of the invention may addi 0239) Pattern formation using the resist composition of tionally include an acetylene alcohol derivative for the the invention may be carried out by a known lithographic purpose of enhancing the shelf Stability. Preferred acetylene technique. For example, the resist composition is applied alcohol derivatives are those having the general formula onto a Substrate Such as a Silicon wafer by Spin coating or the (S1) or (S2) below. like to form a resist film having a thickness of 0.2 to 2.0 nm, which is then pre-baked on a hot plate at 60 to 150° C. for 1 to 10 minutes, and preferably at 80 to 130° C. for 1 to 5 R502 S1 minutes. A patterning mask having the desired pattern is then placed over the resist film, and the film exposed through the Re-c=c--e. mask to an electron beam or to high-energy radiation Such as deep-UW rays, an excimer laser, or X-rays in a dose of – (CH2CH2O),H about 1 to 200 m.J/cm’, and preferably about 5 to 100 R504 R502 S2 mJ/cm, then post-exposure baked (PEB) on a hot plate at 60 to 150° C. for 1 to 5 minutes, and preferably at 80 to 130° R--c=c-l-e C. for 1 to 3 minutes. Finally, development is carried out using as the developer an aqueous alkali Solution, Such as a 0.1 to 5% (preferably 2 to 3%) aqueous solution of tetram ethylammonium hydroxide (TMAH), this being done by a conventional method Such as dipping, puddling, or spraying 0234) In the formulas, R0, RORO-RO and R0 are for a period of 0.1 to 3 minutes, and preferably 0.5 to 2 each hydrogen or a Straight, branched, or cyclic alkyl of 1 to minutes. These steps result in the formation of the desired 8 carbon atoms, and X and Y are each 0 or a positive number, pattern on the Substrate. Of the various types of high-energy satisfying 0sXs 30,0s Ys30, and 0sX+Ys40. radiation that may be used, the resist composition of the 0235 Preferable examples of the acetylene alcohol invention is best Suited to fine pattern formation with, in derivative include Surfynol 61, Surfynol 82, Surfynol 104, particular, deep-UV rays having a wavelength of 248 to 193 US 2002/0197559 A1 Dec. 26, 2002

nm, an excimer laser, X-rays, or an electron beam. The Synthesis Example I-1 desired pattern may not be obtainable outside the upper and lower limits of the above range. 0243 Synthesis of Polymer 1 0244. A mixture of 16.6 g of 3,6-epoxy-2,2-dimethyl-2, 0240 The resist composition comprising the inventive 2a,3,6,6a,7-hexahydrobenzocfuran (Synthesized by mono polymer as a base resin lends itself to micropatterning with tosylating 3,6-epoxy-4-hydroxymethyl-5-(1-hydroxy-1-me Be electron beams or deep-UV rays since it is sensitive to thylethyl)-1-cyclohexane, with simultaneous cyclization), high-energy radiation and has excellent Sensitivity, resolu 104.0 g of 2-ethyl-2-norbornyl 5-norbornene-2-carboxylate, tion, and etching resistance. Especially because of the mini 49.0 g of maleic anhydride, and 18.8 g of 1,4-dioxane was mized absorption at the exposure wavelength of an Arf or heated at 60° C. To the solution was added 7.4 g of KrF excimer laser, a finely defined pattern having Sidewalls 2,2'-azobis(2,4-dimethylvaleronitrile). The solution was perpendicular to the Substrate can easily be formed. stirred for 15 hours while keeping at 60° C. The reaction Solution was cooled to room temperature and dissolved in 500 ml of acetone, which with vigorous stirring, was added EXAMPLE dropwise to 10 liters of isopropyl alcohol. The resulting 0241 Synthesis Examples and Examples are given below solids were collected by filtration and dried in vacuum at 40 by way of illustration and not by way of limitation. The C. for 15 hours, obtaining a polymer, designated Polymer 1, abbreviation MW is a weight average molecular weight as in white powder solid form. The amount was 79.8 g with a measured by GPC using a polystyrene standard, and SEM is yield of 47.1%. Scanning electron microScope. Synthesis Examples I-2 to I-8 Synthesis Example I 0245 Synthesis of Polymers 2-8 0242 Polymers within the scope of the invention were 0246 Polymers 2 to 8 were synthesized by the same Synthesized by the following procedure. procedure as above or a well-known procedure.

(Polymer 1) )d (x = 0.10, d = 0.40, e = 0.50, Mw = 7,700) O O O

O O O

(Polymer 2) )d (x = 0.10, d = 0.40, e = 0.50, Mw = 8,100)

O O eO

(Polymer 3) (x = 0.10, d = 0.40, e = 0.50, Mw = 8,500) )x ( )d - A O O O

O O O Yer

US 2002/0197559 A1 Dec. 26, 2002

Synthesis Example II Synthesis Example II-3 0247 Tetrahydrofuran compounds within the scope of 0254) Synthesis (2) of Monomer 2 the invention were Synthesized by the following procedure. 0255. In 1000 ml of carbon tetrachloride were dissolved 160 g of 3,6-epoxy-4-hydroxymethyl-5-(1-hydroxy-1-meth Synthesis Example II-1 ylethyl)-1-cyclohexene and 230 g of triphenylphosphine. 0248 Synthesis of Monomer 1 With stirring, the mixture was heated to reflux for 28 hours. After cooling, 1000 ml of n-hexane was added to the 0249. In 200 ml of pyridine was dissolved 46.7 g of reaction Solution whereupon the triphenylphosphine oxide 3,6-epoxy-4-cyclohexene-1,2-dimethanol. In a nitrogen formed was filtered off. The filtrate was concentrated in stream, the solution was cooled at 5 C., and 60.0 g of vacuum and distilled in vacuum, obtaining 108 g (yield p-toluenesulfonyl chloride was added thereto. The solution 75%) of the end compound. The physical properties and was stirred at the temperature for one hour and then at room Spectra of this compound matched with those of Synthesis temperature for 8 hours. The reaction mixture was poured Example II-2. into dilute hydrochloric acid, followed by extraction with ethyl acetate. The ethyl acetate Solution was washed with a Synthesis Example II-4 Saturated Sodium chloride Solution, dried over magnesium 0256 Synthesis of Monomer 3 Sulfate, and concentrated in vacuum, yielding crude 3,6- epoxy-2-(p-toluenesulfonyloxymethyl)-4-cyclohexene-1- 0257 Reaction was carried out as in Synthesis Example methanol. The crude product was dissolved in 500 ml of II-2 except that 3,6-epoxy-4-hydroxymethyl-5-(1-hydroxy tetrahydrofuran, which was added dropwise to a mixture of 1-cyclopentyl)-1-cyclohexene was used instead of the 3,6- an aqueous 26%. Sodium hydroxide Solution and 1 g of epoxy-4-hydroxymethyl-5-(1-hydroxy-1-methylethyl)-1- tetra-n-butylammonium chloride. The resulting mixture was cyclohexene in Synthesis Example II-2. The end compound, agitated at room temperature for 12 hours. Thereafter, the 3,6-epoxy-2,2-tetramethylene-2.2a,3,6,6a,7-hexahy tetrahydrofuran layer was separated, washed with water and drobenzo-clfuran was obtained in a yield of 92%. Saturated Sodium chloride Solution, dried over magnesium 0258 Boiling point: 97-100° C./44 Pa Sulfate, concentrated in vacuum, and purified by Silica gel column chromatography, obtaining 31 g (yield 75%) of the 0259) IR (potassium bromide disk): V-2958, 2870, 1340, end compound, 3,6-epoxy-2,2a,3,6,6a,7-hexahydrobenzoc 1325, 1214, 1176, 1032 cm furan. EI-mass spectrum (70 eV): (M/Z)"=39, 51, 68, 77 0260 H-NMR (300 MHz in CDC1): 8=1.30-1.95 (8H, CI-mass spectrum (isobutane): (M/Z)"=109, 121, 139 (M+ m), 2.13 (1H, d, J=7.2 Hz), 2.42(1H, dt, J=3.0, 7.4 Hz), 3.71 H)" (1H, dd, J=3.3, 9.6 Hz), 3.83 (1H, dd, J=7.4, 9.6 Hz), 4.77 (1H, s), 4.89 (1H, s), 6.33-6.39 (2H, m) Synthesis Example II-2

0250) Synthesis (1) of Monomer 2 Monomer 1 0251. In 2000 ml of pyridine was dissolved 360 g of 3,6-epoxy-4-hydroxymethyl-5-(1-hydroxy-1-methylethyl)- 1-cyclohexene. In a nitrogen Stream, the Solution was cooled at 5 C., and 400 g of p-toluenesulfonyl chloride was added thereto. The Solution was stirred at the temperature for one hour and then at room temperature for 18 hours (at this stage, O a corresponding monotosylate, i.e., 3,6-epoxy-4-(1-hy Monomer 2 droxy-1-methylethyl)-5-(p-toluenesulfonyloxymethyl)-1- cyclohexene formed in the reaction System). The reaction mixture was then heated at 60° C., and stirred at the temperature for 4 hours (at this stage, pyridine served as the base to induce cyclization So that the end compound O formed). After cooling, the reaction mixture was poured into Monomer 3 a Saturated Sodium chloride Solution, followed by extraction with ethyl acetate. The ethyl acetate Solution was washed with dilute hydrochloric acid, water and an aqueous Satu rated potassium carbonate Solution, dried over magnesium Sulfate, and concentrated in vacuum. Vacuum distillation of the concentrate gave 308 g (yield 95%) of the end com pound, 3,6-epoxy-2,2-dimethyl-2,2a,3,6,6a,7-hexahy -X) drobenzocfuran. 0252) Boiling point: 65° C/34 Pa Example I 0261 Resist compositions were formulated using the 0253) IR (thin film): v-2856, 1379, 1363, 1209, 1132, inventive polymers as a base resin and examined for Swell 1036 cm 'H-NMR (300 MHz in CDC1): 8=1.18 (3H, s), Suppressing effect. 1.35 (3H, s), 2.01 (1H, d, J=7.2 Hz), 2.47 (1H, dt, J=3.3, 7.4 Hz), 3.73 (1H, dd, J=3.0, 9.4 Hz), 3.92 (1H, dd, J=7.4, 9.4 Examples I-1 to I-4 & Comparative Examples 1, 2 Hz), 4.75 (1H, d, J=0.8 Hz), 4.92 (1H, d, J=1.4 Hz), 6.34 0262 Resist compositions were prepared by blending the (1H, dd, J=1.7, 5.8 Hz), 6.37 (1H, dd, J=1.4, 5.8 Hz) inventive polymers (Polymers 1 to 4) and comparative US 2002/0197559 A1 Dec. 26, 2002 34 polymers (Polymers 9 and 10 shown below) as a base resin, regarded as having been Swollen, with the maximum of a photoacid generator (PAG1), a basic compound and a thickness increase being reported as a Swell (A). Solvent in accordance with the formulation shown in Table 1. They were passed through a Teflon filter having a pore 0264. The formulation and test results of the resist com diameter of 0.2 tim, obtaining resist Solutions. positions are shown in Table 1. Note that the basic com

(Polymer 9) (d = 0.50, e = 0.50, Mw = 7,700) O O O

O Yer (Polymer 10) )a (a = 0.10, d = 0.40, e = 0.50, Mw = 7,900) O O O

O O O

()- SCFSO

(PAG 1)

0263. Each resist solution was spin coated on a silicon pound and solvent used are tributylamine (TBA) and pro wafer having hexamethyldisilazane sprayed thereon at 90 pylene glycol methyl ether acetate (PGMEA), respectively. C. for 90 seconds and heat treated at 110° C. for 90 seconds, The solvent contained 0.01% by weight of surfactant KH-20 forming a resist film of 0.5 um thick. Using a KrF excimer (Asahi Glass Co., Ltd.). laser stepper (Nikon Corp., NA=0.5), the resist film was exposed to light in total eleven Spots at different exposures TABLE 1. including five points Spaced apart from a previously mea Photoacid Basic sured sensitivity (Eth, m/CM) at a pitch of 5% in each of Resin generator compound Solvent Swell descending and ascending directions. Thereafter, the resist (pbw) (pbw) (pbw) (pbw) (A) film was heat treated at 110° C. for 90 seconds, at which point of time the thickness of the film at different exposure Example spots was measured. It is a film thickness (A) before development. The coated Silicon wafer was immersed in a I-1 Polymer 1 PAG 1 TBA PGMEA -33 (80) (1) (0.078) (480) 2.38% tetramethylammonium hydroxide aqueous solution I-2 Polymer 2 PAG 1 TBA PGMEA -52 for 200 seconds for development, at which point of time the (80) (1) (0.078) (480) thickness of the film at different exposure spots was mea I-3 Polymer 3 PAG 1 TBA PGMEA -20 Sured. It is a film thickness (A) after development. For each (80) (1) (0.078) (480) of the different exposure spots, the film thicknesses before I-4 Polymer 4 PAG 1 TBA PGMEA -61 and after development were compared. The Spot where a (80) (1) (0.078) (480) film thickness increase after development was observed was US 2002/0197559 A1 Dec. 26, 2002 35

TABLE 1-continued -continued (DRR2) Photoacid Basic Resin generator compound Solvent Swell (pbw) (pbw) (pbw) (pbw) (A) Comparative Example 1. Polymer 9 PAG 1 TBA PGMEA 181 (DRR3)

(80) (1) (0.078) (480) 2 Polymer 10 PAG 1 TBA PGMEA 89 (80) (1) (0.078) (480)

0265. It is evident from Table 1 that the inventive poly mers are highly effective for Suppressing Swell. Example II 0266 Resist compositions were formulated using inven tive polymers and examined for resolution upon Krf exci mer laser exposure. Examples II-1 to II-17 0267 Evaluation of Resist Resolution 0268 Resist compositions were prepared by using Poly merS 1 to 8 as the base resin, and dissolving the polymer, a photoacid generator (designated as PAG1 and 2), a dissolu tion regulator (designated as DRR1 to 4), a basic compound, and a compound having a =C-COOH group in the mol ecule (ACC1 and 2) in a solvent in accordance with the formulation shown in Table 2. These compositions were each filtered through a Teflon filter (pore diameter 0.2 um), (ACC1) thereby giving resist Solutions. (PAG 1)

(ACC2) ()--soO COH (PAG 2)

0269. These resist solutions were spin coated onto silicon waferS having hexamethyldisilaZane Spray coated thereon at 90° C. for 90 seconds, then heat treated at 110° C. for 90 Seconds to give resist films having a thickness of 0.5 lim. The resist films were exposed using an Krf excimer laser stepper (Nikon Corporation; NA 0.5), then heat treated at (DRR1) 110° C. for 90 seconds, and puddle developed with a solution of 2.38% tetramethylammonium hydroxide in water for 60 Seconds, thereby giving 1:1 line-and-space patterns. 0270. The wafers as developed were sectioned and observed under sectional SEM. The optimal exposure (Eop, mJ/cm) was defined as the exposure which provided a 1:1 resolution at the top and bottom of a 0.30 um line-and-space US 2002/0197559 A1 Dec. 26, 2002 36 pattern. The resolution of the resist under evaluation was Examples III-1 to III-2 defined as the minimum line width (um) of the lines and Spaces that Separated at the optimal exposure. The shape of 0278 Evaluation of Resist Resolution the resolved resist pattern was examined under a SEM and classified into rectangular, rounded head, T-top, forward 0279 Resist compositions were similarly prepared in taper or reverse taper. accordance with the formulation shown in Table 3. 0271 The composition and test results of the resist mate 0280 These resist solutions were spin coated onto silicon rials are shown in Table 2. The solvent and basic compounds waferS having hexamethyldisilaZane Spray coated thereon at used are as follows. It is noted that the Solvent contained 90° C. for 90 seconds, then heat treated at 110° C. for 90 0.01% by weight of surfactant KH-20 (Asahi Glass Co., Seconds to give resist films having a thickness of 0.5 lim. Ltd.). The resist films were exposed using an Arf excimer laser stepper (Nikon Corporation; NA 0.55), then heat treated at 0272 PGMEA: propylene glycol methyl ether acetate 110° C. for 90 seconds, and puddle developed with a 0273 TEA: triethanolamine solution of 2.38% tetramethylammonium hydroxide in water 0274 TMMEA: trismethoxymethoxyethylamine for 60 Seconds, thereby giving 1:1 line-and-space patterns. 0275 TMEMEA: trismethoxyethoxymethoxyethy 0281. The wafers as developed were sectioned and lamine observed under sectional SEM. The optimal exposure (Eop,

TABLE 2

Photoacid Dissolution Basic Resin generator regulator compound Solvent Eop, Resolution, Example (pbw) (pbw) (pbw) (pbw) (pbw) mJ/cm film Shape I-1 Polymer 1 PAG 1 TEA PGMEA 24.0 O.2O rectangular (80) (1) (0.063) (480) I-2 Polymer 2 PAG 1 TEA PGMEA 23.O O.2O rectangular (80) (1) (0.063) (480) I-3 Polymer 3 PAG 1 TEA PGMEA 22.0 O.22 rectangular (80) (1) (0.063) (480) II-4 Polymer 4 PAG 1 TEA PGMEA 25.0 O.22 rectangular (80) (1) (0.063) (480) I-5 Polymer 5 PAG 1 TEA PGMEA 28.0 O.2O rectangular (80) (1) (0.063) (480) I-6 Polymer 6 PAG 1 TEA PGMEA 2O.O O.2O rectangular (80) (1) (0.063) (480) I-7 Polymer 7 PAG 1 TEA PGMEA 29.0 O.2O rectangular (80) (1) (0.063) (480) I-8 Polymer 8 PAG 1 TEA PGMEA 21.0 O.22 rectangular (80) (1) (0.063) (480) II-9 Polymer 5 PAG 2 TEA PGMEA 29.0 O.2O rectangular (80) (1) (0.063) (480) I-10 Polymer 5 PAG 2 TMMEA PGMEA 28.0 O.2O rectangular (80) (1) (0.118) (480) I-11 Polymer 5 PAG 2 TMEMEA PGMEA 29.0 O.22 rectangular (80) (1) (0.173) (480) I-12 Polymer 5 PAG 2 DRR 1 TEA PGMEA 24.0 O.22 somewhat (70) (1) (10) (0.063) (480) rounded head I-13 Polymer 5 PAG 2 DRR 2 TEA PGMEA 25.0 O.2O rectangular (70) (1) (10) (0.063) (480) I-14 Polymer 5 PAG 2 DRR 3 TEA PGMEA 29.0 O.22 rectangular (70) (1) (10) (0.063) (480) I-15 Polymer 5 PAG 2 DRR 4 TEA PGMEA 26.0 O.2O rectangular (70) (1) (10) (0.063) (480) I-16 Polymer 5 PAG 2 ACC 1 TEA PGMEA 26.0 O.22 somewhat (80) (1) (4) (0.063) (480) rounded head I-17 Polymer 5 PAG 2 ACC 2. TEA PGMEA 29.0 O.22 rectangular (80) (1) (4) (0.063) (480)

0276. It is seen from Table 2 that the resist compositions mJ/cm) was defined as the exposure which provided a 1:1 within the Scope of the invention have a high Sensitivity and resolution at the top and bottom of a 0.25 um line-and-space resolution upon Krf excimer laser exposure. pattern. The resolution of the resist under evaluation was defined as the minimum line width (um) of the lines and Example III Spaces that separated at the optimal exposure. The shape of 0277 Resist compositions were formulated using inven the resolved resist pattern was examined under a SEM and tive polymers and examined for resolution upon Arf exci classified into rectangular, rounded head, T-top, forward mer laser exposure. taper or reverse taper. All the patterns were rectangular. US 2002/0197559 A1 Dec. 26, 2002 37

0282. The composition and test results of the resist mate wherein each of R', R R and R" is hydrogen or a straight, rials are shown in Table 3. The solvent and basic compounds branched or cyclic alkyl group of 1 to 15 carbon atoms, or used are as follows. It is noted that the Solvent contained a pair of R and R and a pair of R and R' taken together 0.01% by weight of surfactant KH-20 (Asahi Glass Co., may form a ring wherein each said pair is a Straight, Ltd.). branched or cyclic alkylene group of 2 to 15 carbon atoms 0283 PGMEA: propylene glycol methyl ether acetate and k is equal to 0 or 1. 2. The polymer of claim 1 comprising, in addition to the 0284. TEA: triethanolamine recurring units of formula (1-1), recurring units of the 0285) TMMEA: trismethoxymethoxyethylamine following general formula (2-1):

TABLE 3

Photoacid Dissolution Basic Resin generator regulator compound Solvent Eop, Resolution, Example (pbw) (pbw) (pbw) (pbw) (pbw) mJ/cm film Shape I-1 Polymer 5 PAG 1 TEA PGMEA 18.0 O.15 rectangular (80) (1) (0.063) (480) III-2 Polymer 5 PAG 2 TMMEA PGMEA 19.O O.15 rectangular (80) (1) (0.118) (480)

0286. It is seen from Table 3 that the resist compositions within the Scope of the invention have a high Sensitivity and resolution upon Arf excimer laser exposure. (2-1) ( ) 0287 Japanese Patent Application Nos. 2001-124126 and 2001-124137 are incorporated herein by reference. 0288 Although some preferred embodiments have been described, many modifications and variations may be made thereto in light of the above teachings. It is therefore to be R6 R5 understood that the invention may be practiced otherwise than as Specifically described without departing from the H Z-(R') Scope of the appended claims. o={OR8

1. A polymer comprising recurring units of the following wherein R is hydrogen, methyl or CHCOR", general formula (1-1) or (1-2) and having a weight average R is hydrogen, methyl or COR", molecular weight of 1,000 to 500,000, R7 which may be identical or different in R and R is a Straight, branched or cyclic alkyl group of 1 to 15 ( ) (1-1) carbon atoms, R is an acid labile group, R’ is selected from the class consisting of a halogen atom, (...) a hydroxyl group, a Straight, branched or cyclic alkoxy, acyloxy or alkylsulfonyloxy group of 1 to 15 carbon (...), atoms, and a Straight, branched or cyclic alkoxycarbo R R3 nyloxy or alkoxyalkoxy group of 2 to 15 carbon atoms, in which Some or all of the hydrogen atoms on con R2 O R4 Stituent carbon atoms may be Substituted with halogen atOmS,

(1-2) Z is a single bond or a Straight, branched or cyclic (p+2)-valent hydrocarbon group of 1 to 5 carbon atoms, in which at least one methylene may be substituted with Oxygen to form a chain-like or cyclic ether or two hydrogen atoms on a common carbon may be Substi tuted with oxygen to form a ketone, k' is 0 or 1, and p is 0, 1 or 2. 3. The polymer of claim 1 comprising, in addition to the recurring units of formula (1-1), recurring units of the following general formulae (2-1) and (3): US 2002/0197559 A1 Dec. 26, 2002 38

5. The polymer of claim 1 comprising, in addition to the recurring units of formula (1-2), recurring units of the (2-1) following general formula (2-2):

(2-2)

(3) wherein k", p and R to R are as defined above. 6. A resist composition comprising the polymer of claim 1. 7. A process for forming a resist pattern comprising the whereink', p and R to Rare as defined above, Yis-O- Steps of or -(NR') , and R' is hydrogen or a straight, branched applying the resist composition of claim 6 onto a Substrate or cyclic alkyl group of 1 to 15 carbon atoms. to form a coating, 4. The polymer of claim 1 comprising, in addition to the heat treating the coating and then exposing it to high recurring units of formula (1-1), recurring units of the energy radiation or electron beams through a photo following general formula (4) alone or in combination with mask, and recurring units of the following general formula (2-1), and recurring units of the following general formula (3): optionally heat treating the exposed coating and devel oping it with a developer. 8. A tetrahydrofuran compound of the following general (2-1) formula (5): ( ) (5)

V 7 R6 R5 (...),w H Z-(R') R1 o—(OR8 O R2 wherein each of R and R is hydrogen or a straight, (3) branched or cyclic alkyl group of 1 to 15 carbon atoms, or R" and R taken together may form a ring wherein the combination of R' with R is a straight, branched or cyclic O - Y A O alkylene group of 2 to 15 carbon atoms, and k is equal to 0 or 1. 9. A tetrahydrofuran compound of the following general (4) R6 R5 formula (6): ( ) (6) H O R8C5 wherein k", p, R to R' and Y are as defined above, R is hydrogen, methyl or CH-CoR, R is hydrogen, methyl or COR7, R7 which may be identical or different in RandR wherein each of R and R is hydrogen or a straight, is a Straight, branched or cyclic alkyl group of 1 to 15 carbon branched or cyclic alkyl group of 1 to 15 carbon atoms, or atoms, and R is an acid labile group. R" and R taken together may form a ring wherein the US 2002/0197559 A1 Dec. 26, 2002 39 combination of R' with R is a straight, branched or cyclic alkylene group of 2 to 15 carbon atoms. 10. A method for preparing a tetrahydrofuran compound of the following general formula (5), comprising the Step (a) of Subjecting a diol compound of the following general formula (7) to intramolecular dehydration:

(7) (5) wherein R, R and k are as defined above, and step (a) represents dehydration reaction. wherein R, R and k are as defined above, X is halogen, 11. A method for preparing a tetrahydrofuran compound alkylsulfonyloxy or arylsulfonyloxy, Step (a) represents of the following general formula (5), comprising the Step (a) halogen-Substitution reaction, alkylsulfonylation reaction or of converting a diol compound of the following general arylsulfonylation reaction on hydroxyl, and step (b) repre formula (7) to a compound having an eliminatable group X Sents HX-eliminating reaction. of the following general formula (8-1) and/or (8–2), and the step (b) of treating the compound with a base for cyclization: k . . . .