(12) United States Patent (10) Patent No.: US 8,900,802 B2 Allen Et Al

USOO890O802B2

(12) United States Patent (10) Patent No.: US 8,900,802 B2 Allen et al. (45) Date of Patent: Dec. 2, 2014

(54) POSITIVE TONE ORGANIC SOLVENT (56) References Cited DEVELOPED CHEMICALLY AMPLIFIED RESIST U.S. PATENT DOCUMENTS 3,586,504 A 6, 1971 Coates et al. (71) Applicants: International Business Machines 4,833,067 A 5/1989 Tanaka et al. Corporation, Armonk, NY (US); JSR 5,126.230 A 6/1992 Lazarus et al. Corporation, Tokyo (JP) 5,185,235 A 2f1993 Sato et al. 5,266.424 A 1 1/1993 Fujino et al. 5,554.312 A 9, 1996 Ward (72) Inventors: Robert D. Allen, San Jose, CA (US); 5,846,695 A 12/1998 Iwata et al. Ramakrishnan Ayothi, San Jose, CA 6,599,683 B1 7/2003 Torek et al. (US); Luisa D. Bozano, Los Gatos, CA 7,585,609 B2 9, 2009 Larson et al. (US); William D. Hinsberg, Fremont, (Continued) CA (US); Linda K. Sundberg, Los Gatos, CA (US); Sally A. Swanson, San FOREIGN PATENT DOCUMENTS Jose, CA (US); Hoa D. Truong, San Jose, CA (US); Gregory M. Wallraff, JP 54143232 8, 1979 JP 58219549 12/1983 San Jose, CA (US) JP 6325.9560 10, 1988 (73) Assignees: International Business Machines OTHER PUBLICATIONS Corporation, Armonk, NY (US); JSR Corporation, Tokyo (JP) Ito et al., Positive/negative mid UV resists with high thermal stability, SPIE 0771:24-31 (1987). (*) Notice: Subject to any disclaimer, the term of this (Continued) patent is extended or adjusted under 35 U.S.C. 154(b) by 99 days. Primary Examiner — Brittany Raymond (74) Attorney, Agent, or Firm — Karen Canaan; CanaanLaw, (21) Appl. No.: 13/775,122 P.C. (22) Filed: Feb. 23, 2013 (57) ABSTRACT Prior Publication Data Provided is a method for developing positive-tone chemically (65) amplified resists with an organic developer solvent having at US 2014/0242526A1 Aug. 28, 2014 least one polyhydric alcohol. Such as ethylene glycol and/or glycerol, alone or in combination with an additional organic (51) Int. C. Solvent, such as isopropyl alcohol, and/or water. The organic GO3F 7/26 (2006.01) solvent developed positive tone resists described herein are GO3F 7/32 (2006.01) useful for lithography pattern forming processes; for produc (52) U.S. C. ing semiconductor devices, such as integrated circuits (IC); CPC ...... G03F 7/325 (2013.01) and for applications where basic solvents are not suitable, USPC ...... 430/326 such as the fabrication of chips patterned with arrays of bio (58) Field of Classification Search molecules or deprotection applications that do not require the CPC ...... GO3F 7/0392: G03F 7/20: G03F 7/325 presence of acid moieties.

USPC ...... ------430/322, 326 See application file for complete search history. 36 Claims, 14 Drawing Sheets

630 Siggs -ie- EG (100) p: 3-, -- 2G/PA 70/30) s -A- EGEPA 50/50) -v- EGAAater (90:0 480 - k -Q-TRAH (0.28 N) - 3. : 300- 18 v i A \ ?f: A \ & l, \, W. 18- \, - & - 8.33333333333333339 -g-s-s-s-s-s-s-s-s-s-s-s-s------8 O 2 A. 8 20 22 24 28 28 30 32 EDse (milcm) US 8,900,802 B2 Page 2

(56) References Cited 2007,0269749 A1 11/2007 Schenker

U.S. PATENT DOCUMENTS OTHER PUBLICATIONS

RE42,1287,851,140 B2E 12/20102/2011 TsubakiEgbe Maltabes et al., lx Deep UV Lithography With Chemical Amplifica 2002/0106589 A1 8/2002 Rodney et al. tion for 1-Microti DRAM Production, SPIE 1262:3-7 (1990). U.S. Patent US 8,900,802 B2

f U.S. Patent Dec. 2, 2014 Sheet 2 of 14 US 8,900,802 B2

Kr imaging Results for NORA-MAdMA Resists

PA Developer (100); CD - 200 nm S F.G. 2A

KrF imaging Results for NORA-MAdMA Resists

EG (100) Developer, CD - 200 nm LS F.G. 2B U.S. Patent Dec. 2, 2014 Sheet 3 of 14 US 8,900,802 B2

Krf imaging Results for NORA-MAdMA Resists

EGIPA Developer (70/30); CD - 200 nm S FG. 2C Krf imaging Results for NORA-MAdMA Resists &

EGIWater Developer (90/10); CD - 200 nm S FG. 2D U.S. Patent Dec. 2, 2014 Sheet 4 of 14 US 8,900,802 B2

60 -- EG (00) -o- EGARA (70:30) 50 -A - EG-IRA 50/50) -v- EGANater (90i40) 40 - ----<-- TMAH (0.26 N} ts 300 d

O y \ O - 33-3-3-3-3-3-3-3-3-s-s-s-s 4 6 8 to 12 14 16 18 20 22 24 26 28 30 32 Dose (m.J.lcm)

FG. 3 U.S. Patent Dec. 2, 2014 Sheet 5 of 14 US 8,900,802 B2

TMA Developer (0.26N), CD is 60 nm LS FG. 4A

E-Beam imaging Results for NORA-MAdMA Resists

MA Developer (0.28N), CD is 40 nm S FG. 4B U.S. Patent Dec. 2, 2014 Sheet 6 of 14 US 8,900,802 B2

E-Bear inaging Resuits for NORA-WAdvA Resists

EG Developer (100); CD is 60 frn LS F.G. 4C

E-Beam imaging Results for NORA-MAdMA Resists

EG Developer (100); CD as 40 nm S F.G. D. U.S. Patent Dec. 2, 2014 Sheet 7 of 14 US 8,900,802 B2

: s

s. n .

S U.S. Patent Dec. 2, 2014 Sheet 8 of 14 US 8,900,802 B2

70)

-- EG (90) 8) -o- EG/Water (90/10)* &- EG|Water (85.15) 50 -v- EG|Water (75.25) -e- (TMAH) (0.26 N) 400 -

20)

OO ... XXX & X

{ -8-8-8-8-8-8 4 6 & 10 12 4 6 18 20 22 24 26 28 30 32 Dose indicin) F.G. 6 U.S. Patent Dec. 2, 2014 Sheet 9 of 14 US 8,900,802 B2

Etv imaging Resuits for PS-AAAA Resists Resis fo: S-AdA Resists

EG leveloper 100); C is 32 nm S EG Reveloper (GO), CE - 36 am S FG. A FG. 78 U.S. Patent Dec. 2, 2014 Sheet 10 of 14 US 8,900,802 B2

9 O ------f------r------frn -----r ------f -8- NBHFA. AAAMAResist (EMA; 26 N) -O- NEHFA-RAAdMA Resis: (Eg: 103} t ~&^ NBHFA. AAdiA Resist (ESAPA is 70:30) ...K. NEHFA. AchAA Resis: EGFIFA : 50:50 r KX -(- NBHA - EcoMA Resist (EGPA - 70:30) - 8s - R.A. --> -- hid-MCpl.A Resist (EGl; A = 70:33} 23 KX \\ N -- He-MCpi/A Resist (EGl:PA = 70:30) - , ( V. 3 8-os res f -o- d -c.c. *- C - C - C - C - C - C - ---.E is \W. i A - : - . &e $3. &gs:som - & \e s *:::crease - &x- skissez-85-stressras, & 3 & sers: 2 - -

8 2 4 6 8 20 22 24 28 28 3 U.S. Patent Dec. 2, 2014 Sheet 11 of 14 US 8,900,802 B2

FO)

600-siss -- NBHFA - MAdMA Resist (EGEPA : 70:30) - as A-AA A ~0- N8HFA. AAiMA f\8HFA-8:Cpi/A A& iResist (EGPA : 70:30) SO) -A- N84FA - EcEcMA Resist (EGPA is 70:30) - A -v- He-MCpMA Resist (EGAPA - 70:30) 400 - y -K- He-MCpl.A Resist (EGPA is 50:50) | \ sa 300 1 \ - : o v. -d

AéréY ré-a-3-3-&-8-é-a -g-g-ga-gi-a-g-g-e------2 4 6 8 2 4 6 8 20 22 24, 26 Dose (m3/cm’) FG. 9 U.S. Patent Dec. 2, 2014 Sheet 12 of 14 US 8,900,802 B2

ST;

U.S. Patent Dec. 2, 2014 Sheet 14 of 14 US 8,900,802 B2

Kf CQiast Clive Data for NORA - A.A Resists f -R- Glycerol (400) 600 Q -O-Glycerol Water 80/20) -A'r Glycero, PA 70/30) SO - v \\y/ -v- Glycero, PA 50/50) S 400 - Soros,'a-o-o-o-o-o-o-o-o-o Y "- sis - a -a -a- fs 3.

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8 8 2 4 6 S 2 22 24 28 28 S. 32

FG. 2 US 8,900,802 B2 1. 2 POSITIVE TONE ORGANIC SOLVENT water or another organic solvent. In one embodiment, the DEVELOPED CHEMICALLY AMPLIFED developer comprises a mixture of ethylene glycol and isopro RESIST pyl alcohol. In another embodiment, the developer comprises a mixture of ethylene glycol and water. In a further embodi JOINT RESEARCH AGREEMENT ment, the developer comprises a mixture of glycerol and isopropyl alcohol. The invention described herein is subject to a joint research In another embodiment, the chemically amplified resist agreement between International Business Machines Corpo comprises a composition selected from the group consisting ration and JSR Corporation. 10 of molecular glasses, polyhydroxystyrenes, styrenes having one or more pendant hexafluoroalcohol groups, acrylates, TECHNICAL FIELD methacrylates, and methacrylate fluoroalcohols. The present invention relates generally to photoresists. In one embodiment, the chemically amplified resist com More specifically, the present invention relates to positive prises styrenic NORIA molecular glass protected with a tone resists that are capable of being developed with polyhy 15 2-methyl-2-adamantyl group (NORIA-MAdMA). dric alcohol-based solvents for high resolution imaging. In another embodiment, the chemically amplified resist comprises the polyhydroxystyrene polymer, poly(4-hy BACKGROUND OF THE INVENTION droxystyrene-co-2-methyl-2-adamanty1 methacrylate) As semiconductor device features continue to shrink in (PHS-MAdMA). size, the task of meeting photoresist performance require In a further embodiment, the chemically amplified resist ments for high resolution, low line edge roughness (LER) and comprises a methacrylate-fluoroalcohol polymer selected high photo speed grows increasingly difficult. The challenges from the group consisting of poly(5-acryloyloxy-2,6-norbor in simultaneously meeting the requirements for resolution, nanecarbolactone-co-2-methyl-2-adamantyl methacrylate LER, and sensitivity are known in the art as the “RLS 25 co-2-1,1,1-trifluoro-2'-(trifluoromethyl)-2'-hydroxy)pro Tradeoff.” Current generation chemically amplified photore pyl-3-norbornyl methacrylate) (NBHFA-MAdMA); poly(5- sists, designed to be developed in alkaline base, are capable of acryloyloxy-2,6-norbornanecarbolactone-co-2-methyl-2- high photo speeds, but exhibit unsatisfactory resolution and cyclopentay1 methacrylate-co-2-1,1,1-trifluoro-2'- LER as feature sizes approach 20 nm. In comparison, high (trifluoromethyl)-2'-hydroxy)propyl-3-norbornyl performance solvent-developed non-chemically amplified 30 methacrylate) (NBHFA-McPMA); and poly(5-acryloyloxy resists, such as PMMA (poly methyl methacrylate) resists, 2,6-norbornanecarbolactone-co-2-ethyl-2-cyclopentayl have excellent resolution and LER, but have unacceptably poor photoSpeed in optical imaging. methacrylate-co-2-ethyl-2-adamantyl methacrylate-co-2-1'. The use of solvent development in lithography is not a new 1,1-trifluoro-2'-(trifluoromethyl)-2'-hydroxy)propyl-3-nor idea. In the 1950s, the earliest photoresist systems used 35 bornyl methacrylate) (NBHFA-EcEdMA). organic solvents for developing resist films. See, e.g., William In another embodiment, the chemically amplified resist S. DeForest, Photoresist: Materials and Processes, McGraw comprises the methacrylate polymer, poly((1-methylcyclo Hill, New York, 1975. The first generation 248 nm chemically pentyl methacrylate)-co-(2-methyltricyclo[3.3.1.13.7 de amplified resist, the TBOC (t-butyloxycarbonyloxy) styrene can-2-yl methacrylate)-co-(3-(2-hydroxyethoxy)tricyclo resist, was described 25 years ago for development in an 40 3.3.1.13.7 decan-1-yl methacrylate)-co-(4-Oxa-5- organic solvent. See, e.g., Ito et al., SPIE 0771, 24 (1987); and oxotricyclo[4.2.1.03.7nonan-2-yl methacrylate)) (Hd Maltabes et al., SPIE 1262, 2 (1990). Since the development MCpMA). of the TBOC resist, virtually all chemically amplified resists In a further embodiment, there is provided a method com have been designed to be developed in aqueous base solu prising the steps of: (a) dissolving, in a casting solvent, a tions; consequently, development of solvent-based resists has 45 composition comprising a resist polymer; (b) coating a Sub been largely ignored as an option for modern high resolution strate with the dissolved composition of step (a) to produce a chemically amplified resists. Today, there is an on-going resist film; (c) optionally baking the resist film of step (b); (d) interest in organic developers for negative tone chemically exposing the resist film to radiation; (e) optionally baking the amplified resists (see, e.g., U.S. Pat. No. 7,851,140 B2 to resist film of step (d): (f) developing the resist film with the Tsubaki); however, there are few examples of organic devel 50 organic developer solvent described herein to dissolve opers for positive tone chemically amplified resists. The exposed regions of the film and produce a positive-tone image present invention addresses this need in the art. on the Substrate; and (g) optionally rinsing the film with water after development. SUMMARY OF THE INVENTION 55 In one embodiment, the resist polymer composition of step The present invention provides a method comprising (a) further includes a photoacid generator (PAG). In a pre developing a positive tone image in a chemically amplified ferred embodiment, the PAG is triphenylsulfonium perfluoro resist with an organic developer Solvent comprising a poly 1-butanesulfonate (TPS-N). hydric alcohol, wherein the organic developer solvent has no In another embodiment, the resist polymer composition of more than 2.6x10" M hydroxide ions. In one embodiment, 60 step (a) further includes a quencher, which may be selected the organic developer solvent has no more than 1.0x10 M from the group consisting of base quenchers and radiation hydroxide ions and in another embodiment, the organic sensitive quenchers. In a preferred embodiment, the radiation developer solvent is free of hydroxide ions. sensitive quencher is the photodecomposable base (PDB), In further embodiments of the invention, the polyhydric triphenylsulfonium heptafluorobutyrate (TPS-HFB). In alcohol is selected from the group consisting of ethylene 65 another embodiment, the radiation sensitive quencher is a glycol and glycerol. The developer may comprise the poly PDB selected from the group consisting of Structures (1)- hydric alcohol solvent alone (neat) or in combination with (10): US 8,900,802 B2 4 -continued (6) (1) O

N1to NoH

10 O3 (7)

wherein n is 1, 2, or 3 and m is 1, 2, or 3

(2) (8)

30 wherein n is 1, 2, or 3 (9)

(3) 35

40 (10) O O'S(CH wherein n is 1, 3, or 4 HO (C6H5)3 45 H (4) O H H HO O'S(CH(C6H5)3 O'S(C6H5)3. 50 O HO HO In another embodiment, the casting solvent of step (a) is HO O'S(C6H5)3 selected from the group consisting of propylene glycol 55 methyl ether acetate (PGMEA), propylene glycol monometh O ylether (PGME), and a combination of PGMEA and PGME. In a further embodiment, the radiation of step (d) is (5) selected from the group consisting of deep ultraviolet (DUV) F F. F. F radiation, extreme ultraviolet (EUV) radiation, electronbeam 60 (e-beam) radiation, and ion-beam radiation. F F y K Additional aspects and embodiments of the invention will F be provided, without limitation, in the detailed description of O N & the invention that is set forth below. BRIEF DESCRIPTION OF THE DRAWINGS F XF F7. O'S(C6H5)3 F F 65 FIG. 1 shows structures for the photoresist compositions developed according to the methods of the present invention US 8,900,802 B2 5 6 with the following solvents: ethylene glycol (EG), EG/iso The terms “positive tone resist” refers to a photoresist that propyl alcohol (IPA), and EG/water, and glycerol/IPA. produces a positive tone image upon development, i.e., FIGS. 2A-2D show KrE imagining results for molecular exposed regions are removed during the development pro glass NORIA-MAdMA resists developed with IPA (100); EG CCSS, (100), EG/IPA (70/30); and EG/water (90/10). The term “polyhydric alcohol is used in its traditional FIG. 3 shows KrF contrast curve data for molecular glass sense to refer to an alcohol molecule that has more than one NORIA-MAdMA resists developed with EG (100); EG/IPA hydroxyl group. (70/30 and 50/50); EG/water (90/10); and tetramethylammo The term “DUV or “deep ultraviolet” refers to radiation at nium hydroxide (TMAH 0.26N). wavelengths of 300 nm or shorter, with typical DUV exposure 10 wavelengths for lithography techniques being 248 nm (5 eV) FIGS. 4A-4D show e-beam imaging results for molecular with krypton fluoride (KrE) excimer lasers and 193 nm (6.4 glass NORIA-MAdMA resists developed with TMAH eV) with argon fluoride (ArF) excimer lasers. (0.26N) and EG (100). The term “EUV or “extreme ultraviolet refers to radia FIGS. 5A-5C show EUV imaging results for molecular tion at wavelengths of 50 nm or shorter. Typical EUV expo glass NORIA-MAdMA resists developed with EG (100). 15 sure currently occurs at 10 to 13 nm with 13.5 nm being the FIG. 6 shows KrF contrast curve data for polyhydroxysty most commonly used EUV wavelength. rene PHS-MAdMA resists developed with EG (100); EG/wa The term “chemically amplified resist’ is used in its tradi ter (90/10, 85/15, and 75.25); and TMAH (0.26N). tional sense to refer to a photoresist that is based on acid FIGS. 7A and 7B show EUV imaging results for polyhy catalyzed deprotection and is comprised of a polymer, cata droxystyrene PHS-MAdMA resists developed with EG lyst, additive, and casting solvent. Chemically amplified (100). resists are designed for DUV and shorter wavelengths and FIG. 8 shows KrF contrast curve data for methacrylate have increased sensitivity to exposure energy as a conse fluoroalcohol NBHFA-MAdMA and NBHFA-EcEdMA quence of the chemical amplification. resists developed with TMAH (0.26N), EG (100), and The present invention is directed to the use of an organic EG/IPA (70/30 and 50/50). FIG. 8 also shows methacrylate 25 developer solvent comprising a polyhydric alcohol to develop Hd-MCpMA resists developed with EG/IPA (70/30 and high resolution positive tone images in chemically amplified 50/50). resists. The polyhydric alcohol based developer solvent will FIG. 9 shows ArF contrast curve data for methacrylate necessarily have hydroxide ions in the range of Zero to 2.6x fluoroalcohol NBHFA-MAdMA, NBHFA-MAdMA/NB 10 M. In one embodiment, the solvent has no more than HFA-MCpMA (10/90), and NBHFA-EcEdMA resists devel 30 10x10" M hydroxide ions and in another embodiment, the oped with EG/IPA (70/30). FIG.9 also shows methacrylate solvent is free of hydroxide ions. Hd-MCpMA resists developed with EG/IPA (70/30 and Examples of polyhydric alcohols that may be used to pre 50/50). pare the developer solvent of the present invention include, FIGS. 10A-10C show EUV imaging results for methacry without limitation, ethylene glycol, glycerol, erythritol, threi late-fluoroalcohol NBHFA-MAdMA/NBHFA-MCpMA (10/ 35 tol, arabitol, Xylitol, ribitol, mannitol, Sorbitol, galactitol, 90) resists developed with EG/IPA (70/30). fucitol, iditol, inositol, Volemitol, isomalt, maltitol, lactitol, FIG. 11 shows ArF contrast curve data for methacrylate maltotriitol, maltotetraitol, polyglycidol. The polyhydric fluoroalcohol NFHFA-MAdMA and NBHFA-MAdMA/NB alcohol may be used alone (i.e., neat) to develop the positive HFA-MCpMA (10/90) resists developed with glycerol/IPA tone resist or it be used in combination with water or with (50/50). FIG. 11 also shows the methacrylate HaMCpMA 40 other solvents, such as for example, aliphatic alcohols, diols, resist developed with glycerol/IPA (50/50). and/or triols. A preferred organic solvent for use with the FIG. 12 shows KrE contrast curve data for NORIA organic polyhydric alcohol solvent of the present invention is MAdMA resists developed with glycerol (100), glycerol/ isopropyl alcohol. Examples of other organic solvents that water (80/20), glycerol/IPA (70/30), and glycerol/IPA (50/ may be used in combination with the organic polyhydric 50). 45 alcohol solvent of the present invention include, without limi tation, propanediols, propanetriols, butanediols, butanetriols, DETAILED DESCRIPTION OF THE INVENTION pentanediols, pentanetriols, hexanediols, hexanetriols, octanediols, octanetriols, cyclopropanol, cyclobutanol, Set forth below is a description of what are currently cyclopentanol, phenylmethanol, and phenylethanol. One of believed to be preferred embodiments of the claimed inven 50 skill in the art will appreciate that the formulation of the tion. Any alternates or modifications in function, purpose, or organic solvent developer of the present invention will be set structure are intended to be covered by the claims of this in Such a way as to optimize the RLS response of the resist. application. As used in this specification and the appended The RLS response may be optimized by comparing the LER claims, the singular forms “a,” “an,” and “the include plural of the resist, at a given resolution and imaging dose, after referents unless the context clearly dictates otherwise. The 55 development with an aqueous base and with the organic terms “comprises and/or “comprising, as used in this speci developer solvent of the present invention. fication and the appended claims, specify the presence of The positive tone chemically amplified resists described stated features, integers, steps, operations, elements, and/or herein may be prepared from resist polymers selected from components, but do not preclude the presence or addition of the group consisting of molecular glasses, polyhydroxysty one or more other features, integers, steps, operations, ele 60 renes, styrenes having one or more pendant hexafluoroalco ments, components, and/or groups thereof. hol groups, acrylates, methacrylates, and methacrylate fluo As used herein, the terms “resist’ and “photoresist are roalcohols. An example of a molecular glass resist polymer meant to refer to the same composition and thus, the terms are that may be used to prepare a positive tone molecular glass used interchangeably herein. resist is NORIA molecular glass protected with 2-methyl-2- The term “negative tone resist” refers to a photoresist that 65 adamantyl methacrylate (NORIA-MAdMA). An example of produces a negative tone image upon development, i.e., unex a polyhydroxystyrene (PHS) resist polymer that may be used posed regions are removed during the development process. to prepare a positive tone PHS resist is poly(4-hydroxysty US 8,900,802 B2 7 8 rene-co-2-methyl-2-adamanty1 methacrylate) (PHS invention. Examples 2, 4, 5, 7, and 10 describe the experi MAdMA). An example of a methacrylate resist polymer that mental procedures associated with the generation of the SEM may be used to prepare a methacrylate resist is poly((1-me images. thylcyclopentyl methacrylate)-co-(2-methyltricyclo FIGS. 2A-2D show SEM line/space (LS) patterns at 200 3.3.1.13.7 decan-2-yl methacrylate)-co-(3-(2-hydroxy nm critical dimension (CD) for high performance positive ethoxy)tricyclo[3.3.1.13.7 decan-1-yl methacrylate)-co-(4- tone NORIA-MAdMA molecular glass resists imaged with a oxa-5-oxotricyclo[4.2.1.03.7nonan-2-yl methacrylate)) KrF excimer laser and developed with the following solvents: (Hd-MCpMA). Examples of methacrylate-fluoroalcohol IPA (100), EG (100), EG/IPA (70/30), and EG/water (90/10). resist polymers that may be used to prepare methacrylate FIGS. 2A-2D clearly show that the NORIA-MAdMA resists fluoroalcohol resists include poly(5-acryloyloxy-2,6-norbor 10 developed with the solvents containing EG show far greater nanecarbolactone-co-2-methyl-2-adamantyl methacrylate contrast images than the resist developed with IPA alone. co-2-1,1,1-trifluoro-2'-(trifluoromethyl)-2'-hydroxy) FIGS. 4A-4D show SEML/S patterns at 40 nm and 60 nm propyl-3-norbornyl methacrylate) (NBHFA-MAdMA); poly CD for NORIA MAdMA positive tone resists imaged with (5-acryloyloxy-2,6-norbornanecarbolactone-co-2-methyl-2- e-beam radiation and developed with either 0.26 NTMAH 15 standard base (FIGS. 4A and 4B) or 100% EG (FIGS. 4C and cyclopentayl methacrylate-co-2-1,1,1-trifluoro-2'- 4D). FIGS. 4A-4D show that the EG solvent of the present (trifluoromethyl)-2'-hydroxy)propyl-3-norbornyl invention is equally as effective at developing positive tone methacrylate) (NBHFA-MCpMA); and poly(5-acryloyloxy resists as the standard TMAH solvent. 2,6-norbornanecarbolactone-co-2-ethyl-2-cyclopentay1 FIGS.5A-5C show SEML/S patterns at 28 nm, 30 nm, and methacrylate-co-2-ethyl-2-adamantyl methacrylate-co-2-1'. 32 nm CD for NORIA-MAdMA positive tone resists imaged 1,1-trifluoro-2'-(trifluoromethyl)-2'-hydroxy)propyl-3-nor with EUV radiation and developed with EG (100). bornyl methacrylate) (NBHFA-EcEdMA). FIGS. 7A and 7B show SEML/S patterns at 32 nm and 36 Preparation of the positive tone organic solvent developed nm CD for PHS-MAdMA polyhydroxystyrene positive tone chemically amplified resists described herein involves the resists imaged with EUV radiation and developed with EG. generation of acidic Substituent groups, such as carboxylic 25 FIGS. 10A-10C show SEM L/S patterns at 30 nm, 32 nm, acids or phenols, which render the exposed areas of the resist and 36 mm CD for NBHFA-MAdMA/NBHFA-MCpMA (10/ soluble in polar organic Solvents while the unexposed film 90) methacrylate-fluoroalcohol positive tone resists imaged remains insoluble. The polarity differences between the with EUV radiation and developed with an EG/IPA (70/30). exposed and unexposed regions of the film cause the disso FIGS. 3, 6, 8, 9, 11, and 12 show contrast curve data for lution contrast of the organic solvent developed positive tone 30 styrenic molecular glass (FIGS. 3 and 12), polyhydroxysty photoresists of the present invention. This type of polarity rene (FIG. 6), and methacrylate and methacrylate-fluoroal based dissolution differs from the ionization-dissolution that cohol (FIGS. 8,9, and 11) based positive tone resists, which occurs in aqueous base developed resists, a process that is were developed using the organic Solvent method of the more akin to chemical etching than the polymer solubiliza present invention. Examples 3, 6, 8 and 9 describe the experi tion that occurs with solvent development. As the presence of 35 mental procedures associated with the generation of the con hydroxide ions in the developer solvent risks the introduction trast curve data. of ionization/dissolution processes, rather than the polarity FIG. 3 shows KrF contrast curve data for positive tone based dissolution described herein, it is preferred that the NORIA-MAdMA molecular glass resists developed with EG developer solvent of the present invention has a concentration (100), EG/IPA (70/30), EG/IPA (50/50), EG/water (90/10), of hydroxide ions that is as low as possible. 40 and 0.26 N TMAH for comparative purposes. As shown The polarity based dissolution describes herein also differs therein, the NORIA-MAdMA resists were developed into from the dissolution process that occurs in non-chemically very high contrast resists Suitable for high performance imag amplified resists, such as PMMA resists, where the dissolu ing with all solvents. The EG neat and EG/IPA (both 70/30 tion contrast derives from changes in molecular weight and is and 50/50) developers produced resists with contrast data typically very poor due to the chemical similarity of the 45 comparable to that of the TMAH developed resists. The exposed and unexposed regions of the resist film. EG/water (90/10) developer produced resists with lightly less As a result of the improved polarity-based dissolution pro contrast than EG/IPA and TMAH developed resists. cess described herein, the positive tone organic solvent devel FIG. 12 shows Krf contrast curve data for positive tone oped chemically amplified resists of the present invention NORIA-MAdMA molecular glass resists developed with have the potential to address RLS challenges in a way that 50 glycerol (100), glycerol/water (80/20); glycerol/IPA (70/30): other resist development systems cannot. For example, the and glycerol/IPA (50/50). As shown therein, the neat glycerol resists and methods of the present invention overcome prob and glycerol/water Solvents did not produce high contrast lems that are caused when alkaline developers are used for resists whereas the glycerol/IPA solvents produced very high non-semiconductor lithographic processes, such as the fabri contrast positive tone molecular glass resists. cation of chips patterned with arrays of biomolecules (e.g., 55 FIG. 6 shows KrF contrast curve data for positive tone proteins and oligonucleotides). PHS-MAdMA polyhydroxystyrene positive tone resists FIGS. 2-12 show imaging results and contrast curve data developed with EG, EG/water (90/10), EG/water (85/15), for positive tone resists developed with ethylene glycol (EG) EG/water (75/25), and TMAH for comparative purposes. The alone, isopropyl alcohol (IPA) alone, EG in combination with EG neat developer produced the highest contrast PHS resist IPA, glycerol in combination with IPA, and EG in combina 60 from among the tested developers. tion with water. Positive tone resists developed with TMAH FIG. 8 shows KrE contrast curve data for NBHFA are included for comparative purposes. MAdMA and NBHFA-EcEdMA methacrylate-fluoroalcohol FIGS. 2, 4, 5, 7, and 10 show scanning electron micrograph positive tone resists developed with 0.26 NTMAH (for com (SEM) imaging results for styrenic molecular glass (FIGS. 2. parative purposes), EG (100), and EG/IPA (70/30 and 50/50). 4, 5), polyhydroxystyrene (FIG. 7), and methacrylate-fluoro 65 Optimization of the EG neat developer to incorporate IPA alcohol (FIG. 10) based positive tone resists, which were increased the contrast for the NBHFA-MAdMA resist to developed with the organic solvent method of the present where it was comparable or better than that seen with TMAH. US 8,900,802 B2 10 FIG. 8 also shows KrF contrast curve data for the HaMCpMA It is to be understood by those of skill in the art that the PAB methacrylate positive tone resist; this resist showed compa and PEB temperatures involved with the processing of the rable contrast at both EG/IPA (70/30) and EG/IPA 50/50). positive tone resists will vary with the materials and radiation FIG. 9 shows ArE contrast curve data for NBHFA that are used to carry out the method. For EUV exposure, MAdMA, NBHFA-MAdMA/NBHFA-MCpMA (10/90), 5 typical PAB and PEB temperatures and bake times range and NBHFA-EcEdMA methacrylate-fluoroalcohol positive from 50° C. to 150° C. for 30 to 200 seconds, with preferred tone resists developed with EG/IPA (70/30) as well as ArF temperatures and bake times ranging from 100 to 130°C. for contrast curve data for Ha-MCpMA methacrylate positive 60 to 120 seconds. PAB temperatures will sometimes, but not tone resists developed with EG/IPA (70/30) and EG/IPA (50/ necessarily, be higher than PEB temperatures and PEB bake 50). FIG. 9 illustrates that developer optimization may differ 10 times will sometimes, but not necessarily, belonger than PAB slightly for different resist polymers. As shown therein, the bake times. EG/IPA (70/30) developer produced methacrylate-fluoroal In one embodiment, a suitable PAG may be used in the cohol resists with excellent contrast while the EG/IPA (50/50) processing of the organic solvent developed positive tone developer produced methacrylate resists with improved con resists of the present invention. The PAG present in the com trast over those produced with the EG/IPA (70/30) developer. 15 position is typically in the range of about 1-15 mol% and may FIG. 11 shows ArE contrast curve data for NBHFA or may not be bound to the polymer. Those of skill in the art MAdMA and NBHFA-MAdMA/NBHFA-MCpMA (10/90) will appreciate that any PAG incorporated into the resists methacrylate-fluoroalcohol positive tone resists developed described herein should have high thermal stability, i.e., be with glycerol/IPA (50/50) as well as ArF contrast curve data stable to at least 140° C., so they are not degraded during for Ha-MCpMA methacrylate positive tone resists developed pre-exposure processing. with glycerol/IPA (50/50). While the glycerol/IPA developer Examples of PAGs that may be used with the positive-tone produced high contrast methacrylate-fluoroalcohol resists, resists of the present invention include, without limitation, the glycerol/IPA developer failed to produce a suitable meth Sulfonates, onium salts, aromatic diazonium salts, Sulfonium acrylate resist. The data from FIG. 11 indicates that optimi salts, diaryliodonium salts and Sulfonic acid esters of N-hy zation of the solvent with a different polyhydric alcohol, 25 droxyamides or N-hydroxyimides. Specific examples oftypi organic solvent, and/or water concentration may be necessary cal PAGs may be selected from the following list of PAGs: to improve the contrast of the resulting methacrylate resist (1) Sulfonium salts, such as triphenylsulfonium perfluoro (similar to that seen in FIG. 12). 1-butanesulfonate (TPS-N), triphenylsulfonium perfluo The organic solvent developed positive tone resists of the romethanesulfonate (triphenylsulfonium triflate), triphenyl present invention are prepared as follows: (a) the positive tone 30 Sulfonium perfluoropentanesulfonate, triphenylsulfonium resist polymer (see e.g., Table 1) is dissolved in a casting hexafluoroantimonate, triphenylsulfonium hexafluoroarsen solvent; (b) the dissolved composition is coated on a substrate ate, triphenylsulfonium hexafluorophosphate, triphenylsul to produce a resist film; (c) optionally, the resist film is baked fonium bromide, triphenylsulfonium chloride, triphenylsul to drive off the casting solvent (the post-application bake or fonium iodide, 2,4,6-trimethylphenyldiphenylsulfonium PAB); (d) the film is exposed to radiation; (e) optionally, the 35 perfluorobutanesulfonate, 2,4,6-trimethylphenyldiphenyl film is baked (post-exposure bake or PEB); (f) the film is sulfonium benzenesulfonate, diphenylethylsulfonium chlo developed with the organic developer solvent described ride, and phenacyldimethylsulfonium chloride; herein; and (g) optionally, after development, the film is (2) halonium salts, particularly iodonium salts, including rinsed with water. diphenyliodonium perfluoromethanesulfonate (diphenyli Examples of casting solvents that may be used to dissolve 40 odonium triflate), diphenyliodonium perfluorobutane the positive tone resist polymers include, without limitation, Sulfonate, diphenyliodonium perfluoropentanesulfonate, propylene glycol methyl ether acetate (PGMEA), propylene diphenyliodonium hexafluoroantimonate, diphenyliodonium glycol monoethyl ether (PGME), or a combination of hexafluoroarsenate, bis-(t-butylphenyl)iodonium triflate, and PGMEA and PGME. One of skill in the art will appreciate bis-(t-butylphenyl)-iodonium camphanylsulfonate; that any other casting solvents used in the semiconductor arts 45 (3) C.C.'-bis-Sulfonyl-diazomethanes such as bis(p-tolu may be substituted for any of the foregoing. enesulfonyl)diazomethane, methylsulfonyl p-toluenesulfo Examples of substrates that may be used to prepare the nyldiazomethane, 1-cyclohexylsulfonyl-1-(1,1-dimethyleth resist films include, without limitation, silicon (Si), gallium ylsulfonyl)diazomethane, and bis(cyclohexylsulfonyl) arsenide (GaAs), indium phosphide (InP), glass, and metals, diazomethane; Such as gold (Au), copper (Cu), and aluminum (Al). One of 50 (4) trifluoromethanesulfonate esters of imides and skill in the art will appreciate that any other substrates used in hydroxyimides, e.g., C.-(trifluoromethylsulfonyloxy)-bicyclo the semiconductor arts may be substituted for any of the 2.2.1]hept-5-ene-2,3-dicarboximide (MDT); foregoing. (5) nitrobenzyl sulfonate esters such as 2-nitrobenzyl Exposure of the organic solvent developed positive tone p-toluenesulfonate, 2,6-dinitrobenzyl p-toluenesulfonate, photoresist of the present invention may occur by any Suitable 55 and 2,4-dinitrobenzyl p-trifluoromethylbenzene sulfonate; method including without limitation, DUV radiation, EUV (6) sulfonyloxynaphthalimides such as N-camphorsulfo radiation, ion-beam projection, X-ray radiation, e-beam radia nyloxynaphthalimide and N-pentafluorophenylsulfonylox tion, and focused beam radiation. ynaphthalimide; After exposure, the positive tone photoresist is developed (7) pyrogallol derivatives (e.g., trimesylate of pyrogallol); by contacting the photoresist layer with the organic polyhy 60 (8) naphthoduinone-4-diazides; dric alcohol-based solvent disclosed herein to selectively dis (9) alkyl disulfones: solve the areas of the photoresist that were exposed to radia (10) s-triazine derivatives, as described in U.S. Pat. No. tion. The unexposed areas of the photoresist remain intact to 4,189,323; and produce the positive tone image. The resulting lithographic (11) miscellaneous Sulfonic acid generators including t-bu structure on the substrate is then typically dried to remove any 65 tylphenyl-O-(p-toluenesulfonyloxy)-acetate, t-butyl-O-(p- remaining developer. If a top coat has been used, it can be toluenesulfonyloxy)acetate, and N-hydroxy-naphthalimide dissolved by the developer in this step. dodecane sulfonate (DDSN), and benzoin tosylate. US 8,900,802 B2 11 12 Other suitable photoacid generators are disclosed in Reich -continued manis et al., Chemistry of Materials 3:395 (1991). (5) In another embodiment, a quencher may be used in the F F. F. F processing of the organic solvent developed positive tone F F y K F F resists of the present invention. The quencher may be a base quencher or a radiation sensitive quencher, Such as a photo O N N O decomposable base (PDB). F 12F F F F F O'S(CH(C6H5)3. Examples of base quenchers that may be used with the O'S(C6H5)3 present invention include, without limitation, aliphatic 10 amines, aromatic amines, and combinations thereof. Specific examples of base quenchers include, without limitation, Examples of asymmetrical PDBs that may be used with the 2-phenylbenzimidazole; tert-butyl 2-phenyl-1,3-benzodiaz present invention include Structures 7-10: ole-1-carboxylate; dimethylamino pyridine: 7-diethylamino (7) 4-methyl coumarin (Coumarin 1); tertiary amines; sterically 15 hindered diamine and guanidine bases, such as 1.8-bis(dim ethylamino)naphthalene (e.g., PROTON SPONGED); ber berine; and polymeric amines (such as in the PLURONIC(R) HC or TETRONICR) series commercially available from BASF). Tetra alkyl ammonium hydroxides or cetyltrimethyl ammo nium hydroxide may be used as a base quencher when the PAG is an onium salt. (8) Examples of PDBs that may be used with the present O invention include, without limitation, arylsulfonium or iodo 25 nium salts of carboxylates, hydroxides, and Sulfamates. An example of a monofunctional PDB that can be used with the present invention is triphenylsulfonium heptafluorobutyrate H (TPS-HFB). Additional PDBs that may be used with the present invention are described in commonly owned patent 30 application Ser. No. 13/219,599 to Ayothi et al and include fluorinated bifunctional PDBs, asymmetrical PDBs, and dicarboxylate anion PDBs. Examples of fluorinated bifunctional PDBs that may be (9) used with the present invention include Structures 1, 2, and 5: 35

(1) O O'S(C6H5)3 40 pi F (10) F 45 O

iii. H F

F 50 O'S(C6H5)3 O wherein n is 1, 2, or 3 and Examples of dicarboxylate anion PDBs that may be used m is 1, 2, or 3 55 with the present invention include Structures 3, 4, and 6: (2) O (3) O'S(C6H5)3 O pi F 60 F O'S(C6H5)3 O 65 wherein n is 1, 2, or 3 wherein n is 1, 3, or 4 US 8,900,802 B2 13 14 -continued Poly(5-acryloyloxy-2,6-norbornanecarbolactone-co-2-ee (4) thyl-2-cyclopentayl methacrylate-co-2-ethyl-2-adamanty1 O methacrylate-co-2-1'1'.1'-trifluoro-2'-(trifluoromethyl)- HO O'S(CH(C6H5)3 2'-hydroxy)propyl-3-norbornyl methacrylate) NBHFA 5 EcEdMA (resist polymer); and HO Poly((1-methylcyclopentyl methacrylate)-co-(2-methyltri HO cyclo[3.3.1.13.7 decan-2-yl methacrylate)-co-(3-(2-hy HO droxyethoxy)tricyclo[3.3.1.13.7 decan-1-yl methacry O'S(C6H5)3 late)-co-(4-Oxa-5-oxotricyclo[4.2.1.03.7 nonan-2-yl O 10 methacrylate)) Ha-MCpMA (resist polymer). (6) Triphenylsulfonium perfluoro-1-butanesulfonate (TPS-N) O (photoacid generator; PAG); Triphenylsulfonium heptafluorobutyrate (TPS-HFB) (base quencher) was synthesized from triphenylsulfonium bro 15 mide and silver heptafluorobutyrate by anion exchange N1 No reaction. H DUV42P or ARC29A bottom anti-reflective coating H (BARC) coated silicon wafers (substrate), obtained from Brewer Science, Inc. Rolla, Mo., USA; Propylene glycol monomethylether acetate (PGMEA) O (casting solvent), obtained from Sigma-Aldrich Corp., St. The organic solvent developed positive tone chemically Louis, Mo., USA; amplified resists described herein have utility in a number of Propylene glycol monomethylether (PGME) (casting sol applications. For example, they may be used to manufacture vent) Aldrich; Ethylene Glycol (EG) (developer solvent), Semiconductor devices, such as integrated circuits. As noted 25 obtained from Sigma-Aldrich Corp., St. Louis, Mo., USA: above, they may also be useful for applications where basic Glycerol (developer solvent), obtained from Sigma-Ald solvents are not suitable, such as the fabrication of chips rich Corp., St. Louis, Mo., USA: patterned with arrays of biomolecules or deprotection appli Isopropyl Alcohol (IPA) (developer solvent), obtained cations that do not require the presence of acid moieties. from Sigma-Aldrich Corp., St. Louis, Mo., USA: It is to be understood that while the invention has been 30 0.26 N Tetramethyl ammonium hydroxide (TMAH) (de described in conjunction with the embodiments set forth veloper), obtained from Fuji Film, Cypress, Calif., USA. above, the foregoing description as well as the examples that KrF excimer laser exposures (248 nm) were performed in follow are intended to illustrate and not limit the scope of the an ASML 550/300D stepper (Annular, NA=0.61: o 0.60; invention. Further, it is to be understood that the embodiments O=0.35). and examples set forth herein are not exhaustive and that 35 EUV exposures were performed with the Lawrence Ber modifications and variations of the invention will be apparent keley National Laboratory SEMATECH.R. (Sematech Inc., to those of ordinary skill in the art without departing from the Austin,Tex., USA) Micro-Exposure Tool (LBNL-MET) (Ro scope and spirit of the invention. tated Dipole; NA=0.3). All patents and publications mentioned herein are incor E-beam exposures were performed with a Leica VB6 porated by reference in their entireties. 40 lithography tool at 100 keV. The following additional definitions are used in the EXPERIMENTAL Examples: FT-film thickness; The following examples are set forth to provide those of Dev-development; ordinary skill in the art with a complete disclosure of how to 45 PAB post-application bake; and make and use embodiments of the invention as set forth PEB-post-exposure bake. herein. While efforts have been made to ensure accuracy with respect to variables, such as amounts, temperature, etc., EXAMPLE 1. experimental error and deviations should be taken into account. Unless indicated otherwise, parts are parts by 50 Processing of Organic Solvent Developed Positive weight, temperature is degrees centigrade, and pressure is at Tone Photoresists or near atmospheric. All polymers used in the examples were synthesized in the Resist formulations were prepared by mixing the polymer laboratory using commercially available chemicals. The fol or molecular glass (3 to 5 wt %) with the PAGTPS-N and the lowing materials were used in the examples: quencher TPS-HFB in PGMEA or a PGMEA/PGEME mix NORIA molecular glass protected with 2-methyl-2-adaman 55 ture. The PAG and the quencher concentration was 0.25 and tyl methacrylate NORIA-MAdMA, (50/50) (resist poly 0.1 mmole per gram of polymer, respectively. The resist for mer); mulations were filtered through a 0.2 Lum Teflon filter, spin Poly(4-hydroxystyrene-co-2-methyl-2-adamantyl methacry coated onto a BARC coated substrate, and post-apply baked late) (PHS-MAdMA (60/40) (resist polymer); (PAB) at 110° C. for 60 seconds. After exposure, the wafer Poly(5-acryloyloxy-2,6-norbornanecarbolactone-co-2-me 60 was put through PEB at 110° C. for 60 seconds, and devel thyl-2-adamantyl methacrylate-co-2-1", 1", 1'-trifluoro-2'- oped in either aqueous base, TMAH (0.26 N), EG (100), (trifluoromethyl)-2'-hydroxy)propyl-3-norbornyl meth EG/IPA (70/30 or 50/50), EG/Water (90/10), glycerol (100), acrylate) NBHFA-MAdMA (40/15/45) (resist polymer): or glycerol/IPA (70/30 or 50/50) for 30 to 120 seconds. Each Poly(5-acryloyloxy-2,6-norbornanecarbolactone-co-2-me wafer developed with TMAH or organic solvent was rinsed thyl-2-cyclopentayl methacrylate-co-2-1", 1", 1'-trifluoro 65 with water before drying. 2'-(trifluoromethyl)-2'-hydroxy)propyl-3-norbornyl meth Table 1 summarizes resist compositions that were prepared acrylate)NBHFA-MCpMA, (40/15/45) (resist polymer): and evaluated using the foregoing procedure. US 8,900,802 B2 15 16 TABLE 1.

RESIST FORMULATIONS

RESIST TYPE RESIST POLYMER PAG QUENCHER SOLVENT Molecular NORIA- NORIA-MACMA TPS-N TPS-HFB PGMEA Glass MAdMA (100) (0.25M) (0.1M) Polyhydroxy- PHS- PHS-MAdMA (100) TPS-N TPS-HFB PGMEA styrene (PHS) MAdMA (0.25M) (0.1M) Methacrylate- NBHFA- NBHFA-MAdMA TPS-N TPS-HFB PGMEA Fluoroalcohol MAdMA (100) (0.25M) (0.1M) NBHFA- NBHFA- TPS-N TPS-HFB PGMEA MAdMA/NBHFA- MAdMA/NBHFA- (0.25M) (0.1M) MCpMA MCpMA (10/90) NBHFA- NBHFA-EcECMA TPS-N TPS-HFB PGMEAPGME EcEdMA (100) (0.25M) (0.1M) (20/80) Methacrylate Hol-MCpMA Hd-MCpMA (100) TPS-N TPS-HFB PGMEA (0.25M) (0.1M)

Structures for the polymers and molecular glass composi- 2O cessing conditions: Resist composition=NORIA-MAdMA/ tions from Table 1 are shown in FIG.1. Also shown in FIG. 1 TPS-N/TPS-HFB; Substrate=DUV42P; FT=60 nm: are the structures for the TPS-N PAG and the TPS-HFB base PAB=110° C./60s; Exposure—e-beam; PEB=110° C./60s: quencher. The polymer percentages indicated in Table 1 apply Dev=30s with TMAH (100) and EG (100). to the polymers used in the following examples. In the fol FIGS. 4A-4D show SEM L/S patterns at the following lowing examples, the term “methacrylate-type' is used to 25 e-beam doses and critical dimensions: Es=155 uC/cm and refer to both methacrylate-fluoroalcohol and methacrylate CD=60 nm (FIG. 4A); Es=160 uC/cm and CD-40 nm (FIG. resists. 4B); Es=170 uC/cm and CD=60 nm (FIG. 4C); and Es=155 uC/cm and CD-40 nm (FIG. 4D). EXAMPLE 2 30 EXAMPLE 5 KrF Imaging of NORIA-MAdMA Resists EUV Imaging of NORIA-MAdMA Resists Top-down SEM images for the KrE exposed NORIA MAdMA resist of Table 1 are shown in FIGS 2A-2D. The Top-down SEM images for the EUV exposed NORIA resists were prepared with the following materials and pro 35 MAdMA resist of Table 1 are shown in FIGS. 5A-5C. The cessing conditions: Resist composition=NORIA-MAdMA/ resists were prepared with the following materials and pro TPS-N/TPS-HFB; Substrate=DUV42P; FT=80 nm: cessing conditions: Resist composition=NORIA-MAdMA/ PAB=110° C./60 s: Exposure-KrF; PEB=110° C./60 s: TPS-N/TPS-HFB; Substrate=DUV42P; FT=60 nm: Dev=30s with IPA (100), EG (100), EG/IPA (70/30), and PAB=110° C./60 s: Exposure-EUV; PEB=110° C./60 s: EG/water (90/10). 40 Dev=30s with EG (100). FIGS. 2A-2D show SEM line/space (LS) patterns at 200 FIGS.5A-5C show SEM L/S patterns at the EUV dose of nm critical dimension (CD) at the following Krf laser doses: 21 m.J/cm and the following critical dimensions: CD=28 nm. 25 mJ/cm (FIG. 2A); 27 mJ/cm (FIGS. 2B and 2C); and 29 (FIG.5A); CD=30 nm (FIG.5B); and CD=32 nm (FIG.5C). mJ/cm (FIG. 2D). 45 EXAMPLE 6 EXAMPLE 3 KrF Exposure of PHS-MAdMA Resists KrF Exposure of NORIA-MAdMA Resists KrF contrast curve data for the PHS-MAdMA resist of KrF contrast curve data for the NORIA-MAdMA resist of 50 Table 1 is shown in FIG. 6. The resists were prepared with the Table 1 is shown in FIGS. 3 and 12. The resists were prepared following materials and processing conditions: Resist with the following materials and processing conditions: composition=PHS-MAdMA/TPS-N/TPS-HFB; Resist composition=NORIA-MAdMA/TPS-N/TPS-HFB; Substrate=DUV42P; FT=60 nmi; PAB=110° C./60 s: Substrate=DUV42P; FT=60 nmi; PAB=110° C./60 s: Exposure-Krf; PEB=110° C./60s: Dev=30s with EG (100), Exposure-Krf; PEB=110° C./60s: Dev=30s with EG (100), 55 EG/water (90/10), (85/15), and (75/25), and TMAH (100). EG/IPA (70/30) and (50/50), EG/water (90/10), and TMAH (100) (FIG. 3); and Dev=60s with glycerol (100), glycerol/ EXAMPLE 7 water (80/20), and glycerol/IPA (70/30) and (50/50) (FIG. 12). EUV Imaging of PHS-MAdMA Resists 60 EXAMPLE 4 Top-down SEM images for the EUV exposed PHS MAdMA resist of Table 1 is shown in FIGS. 7A and 7B. The E-Beam Imaging of NORIA-MAdMA Resists resists were prepared with the following materials and pro cessing conditions: Resist composition=PHS-MAdMA/ Top-down SEM images for the e-beam exposed NORIA 65 TPS-N/TPS-HFB; Substrate=DUV42P; FT=60 nm: MAdMA resist of Table 1 are shown in FIGS 4A-4D. The PAB=110° C./60 s: Exposure-EUV; PEB=110° C./60 s: resists were prepared with the following materials and pro Dev=30s with EG (100). FIGS. 7A and 7B show SEM L/S US 8,900,802 B2 17 18 patterns at the EUV dose of 22 m/cm and the following 7. The method of claim 1, wherein the organic developer critical dimensions: CD=32 nm (FIG. 7A) and CD-36 nm Solvent includes an additional organic solvent. (FIG. 7B). 8. The method of claim 7, wherein the polyhydric alcohol is ethylene glycol and the organic developer Solvent com EXAMPLE 8 prises a mixture of ethylene glycol and isopropyl alcohol. 9. The method of claim 7, wherein the polyhydric alcohol KrF Exposure of Methacrylate-Type Resists is glycerol and the organic developer solvent comprises a mixture of glycerol and isopropyl alcohol. KrF contrast curve data for the methacrylate-fluoroalcohol 10. The method of claim 1, wherein the chemically ampli and methacrylate resists of Table 1 are shown in FIG.8. The 10 resists were prepared with the following materials and pro fied resist comprises a composition selected from the group cessing conditions: Resist compositions=NBHFA-MAdMA/ consisting of molecular glasses, polyhydroxystyrenes, sty TPS-N/TPS-HFB, NBHFA-EcEdMA/TPS-N/TPS HFB, and renes having one or more pendant hexafluoroalcohol groups, Hd-MCpMA/TPS-N/TPS-HFB; Substrate=DUV42P: acrylates, methacrylates, and methacrylate fluoroalcohols. FT=60 nm: PAB=110° C./60s: Exposure=KrF; PEB=110° 15 11. The method of claim 1, wherein the chemically ampli C/60s: Dev=30 or 60s with EG (100), EG/IPA (70/30) and fied resist comprises a styrenic molecular glass. (50/50). 12. The method of claim 11, wherein the styrenic molecu lar glass is NORIA molecular glass protected with a 2-me EXAMPLE 9 thyl-2-adamantyl group (NORIA-MAdMA). 13. The method of claim 1, wherein the chemically ampli ArF Exposure of Methacrylate-Type Resists fied resist comprises a polyhydroxystyrene polymer. 14. The method of claim 13, wherein the polyhydroxysty ArF contrast curve data for the methacrylate-fluoroalcohol rene polymer is poly(4-hydroxystyrene-co-2-methyl-2-ada and methacrylate resists of Table 1 are shown in FIGS. 9 and mantyl methacrylate) (PHS-MAdMA). 11. The resists were prepared with the following materials 25 15. The method of claim 1, wherein the chemically ampli and processing conditions: Resist compositions=NBHFA fied resist comprises a methacrylate-fluoroalcohol polymer. MAdMA/TPS-N/TPS-HFB, NBHFA-MAdMA/NBHFA 16. The method of claim 15, wherein the methacrylate MCpMA (10/90)/TPS-N/TPS HFB, NBHFA-EcEdMA/ fluoroalcohol polymer is selected from the group consisting TPS-N/TPS HFB and Ha-MCpMA/TPS-N/TPS-HFB; of poly(5-acryloyloxy-2,6-norbornanecarbolactone-co-2- Substrate=ARC29A; FT=60 nmi; PAB=110° C./60 s: 30 methyl-2-adamantyl methacrylate-co-2-1", 1", 1'-trifluoro-2'- Exposure=ArF; PEB=110° C./60s: Dev=60s with EG/IPA (trifluoromethyl)-2'-hydroxy)propyl-3-norbornyl methacry (70/30) and (50/50) and glycerol/IPA (50/50). late) (NBHFA-MAdMA): poly(5-acryloyloxy-2,6- norbornanecarbolactone-co-2-methyl-2-cyclopentay1 EXAMPLE 10 methacrylate-co-2-1,1,1-trifluoro-2'-(trifluoromethyl)-2'- 35 hydroxy)propyl-3-norbornyl methacrylate) (NBHFA EUV Imaging of NBHFA-MAdMA Resists McPMA); and poly(5-acryloyloxy-2,6-norbornanecarbolac tone-co-2-ethyl-2-cyclopentayl methacrylate-co-2-ethyl-2- Top-down SEM images for the EUV exposed NBHFA adamantyl methacrylate-co-2-1,1,1-trifluoro-2'- MAdMA/NBHFA/MCpMA (10/90) resist of Table 1 are (trifluoromethyl)-2'-hydroxy)propyl-3-norbornyl shown in FIGS. 10A-10C. The EUV imaging was carried out 40 methacrylate) (NBHFA-EcEdMA). with the following materials and processing conditions: 17. The method of claim 1, wherein the chemically ampli Resist composition=NBHFA-MAdMA/NBHFA-MCpMA fied resist comprises a methacrylate polymer. (10/90)/TPS-N/TPS-HFB); Substrate=DUV 2P; FT=60 nm: 18. The method of claim 17, wherein the methacrylate PAB=110° C./60 s: Imaging EUV LBNL-MET (Rotated polymer is poly((1-methylcyclopentyl methacrylate)-co-(2- Dipole); PEB=110° C./60s: Dev=30s with EG/IPA (70/30). 45 methyltricyclo[3.3.1.13.7 decan-2-yl methacrylate)-co-(3- FIGS. 10A-10C show SEM L/S patterns at the EUV dose (2-hydroxyethoxy)tricyclo[3.3.1.13.7 decan-1-yl methacry of 21 m.J/cm (FIGS. 10A and 10B) and 20 m.J/cm (FIG. late)-co-(4-oxa-5-oxotricyclo[4.2.1.03.7nonan-2-yl 10C) and the following critical dimensions: CD=30 nm (FIG. methacrylate)) (Hd-MCpMA). 10A); CD=32 nm (FIG. 10B); and CD=36 nm (FIG. 10C). 19. A method comprising the steps of: 50 (a) dissolving, in a casting solvent, a composition compris We claim: ing a resist polymer; 1. A method comprising: (b) coating a Substrate with the dissolved composition of developing a positive tone image in a chemically amplified step (a) to produce a resist film; resist with an organic developer solvent, wherein the (c) optionally baking the resist film of step (b): organic developer solvent comprises a polyhydric alco 55 (d) exposing the resist film to radiation; hol and further wherein the organic developer solvent (e) optionally baking the resist film of step (d); has no more than 2.6x10M hydroxide ions. (f) developing the resist film with an organic developer 2. The method of claim 1, wherein the organic developer Solvent to dissolve exposed regions of the film and pro solvent has no more than 1.0x10" M hydroxide ions. duce a positive-tone image on the Substrate, wherein the 3. The method of claim 1, wherein the organic developer 60 organic developer solvent comprises a polyhydric alco solvent is free of hydroxide ions. hol and further wherein the organic developer solvent 4. The method of claim 1, wherein the polyhydric alcohol has no more than 2.6x10M hydroxide ions; and is ethylene glycol. (g) optionally rinsing the film with water after develop 5. The method of claim 1, wherein the organic developer ment. Solvent comprises a mixture of ethylene glycol and water. 65 20. The method of claim 19, wherein the organic developer 6. The method of claim 1, wherein the polyhydric alcohol solvent of step (f) has no more than 10x10 M hydroxide is glycerol. 1O.S. US 8,900,802 B2 19 20 21. The method of claim 19, wherein the organic developer -continued solvent of step (f) is free of hydroxide ions. (3) 22. The method of claim 19, wherein the polyhydric alco- O hol of step (f) is ethylene glycol. O'S(C6H5)3 23. The method of claim 22, wherein the organic developer 5 pi Solvent of step (f) comprises a mixture of ethylene glycol and H Water. 24. The method of claim 19, wherein the polyhydric alco hol of step (f) is glycerol. 10 O'S(C6H5)3 25. The method of claim 19, wherein the organic developer Solvent of step (f) includes an additional organic solvent. O 26. The method of claim 25, wherein the polyhydric alco- wherein n is 1, 3, or 4 hol of step (f) is ethylene glycol and the organic developer (4) solvent comprises a mixture of ethylene glycol and isopropyl is O alcohol. O'S(C6H5)3 27. The method of claim 25, wherein the polyhydric alco- HO hol of step (f) is glycerol and the organic developer Solvent HO comprises a mixture of glycerol and isopropyl alcohol. HO 28. The method of claim 19, wherein the resist polymer 20 composition of step (a) further includes a photoacid generator HO O'S(C6H5)3 (PAG). 29. The method of claim 28, wherein the PAG is triphenyl- O sulfonium perfluoro-1-butanesulfonate (TPS-N). (5) 30. The method of claim 19, wherein the resist polymer 25 composition of step (a) further includes a quencher. F F 31. The method of claim 30, wherein the quencher is O N N selected from the group consisting of base quenchers and SS O radiation sensitive quenchers. F 32. The method of claim 31, wherein the radiation sensitive 30 --- F 'F F. F F F F is (C6H5) quencher is a photodecomposable base (PDB). O'S(CH5)3 6Lls 3 33. The method of claim32, wherein the PBD is triphenyl sulfonium heptafluorobutyrate (TPS-HFB). (6) 34. The method of claim 32, wherein the PDB is selected O from the group consisting of Structures (1)-(10): 35 H O+S(C6H5)3

(1) H Y1\o O H O'S(C6H5)3 40 H pi O+S(C6H5)3 F O F 45 7 O O (7)

F iii. HO O'S(CH(C6H5)3

F 50 H3C O'S(C6H5)3 H H O O'S(C6H5)3 wherein n is 1, 2, or 3 and O m is 1, 2, or 3 55 (2) O (8)

wherein n is 1, 2, or 3 US 8,900,802 B2 21 22 -continued (9) O HN O'S(C6H5)3 5

H H

H O'S(C6H5)3 10 O (10) O HO O'S (C6H5)3 15 H

H H O'S(C6H5)3. 2O O

35. The method of claim 19, wherein the casting solvent of step (a) is selected from the group consisting of propylene glycol methyl ether acetate (PGMEA), propylene glycol 25 monomethylether (PGME), and a combination of PGMEA and PGME. 36. The method of claim 19, wherein the radiation of step (d) is selected from the group consisting of deep ultraviolet (DUV) radiation, extreme ultraviolet (EUV) radiation, elec tron beam (e-beam) radiation, and ion-beam radiation. k k k k k