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(12) United States Patent (10) Patent No.: US 8,343,365 B2 Yoshibayashi (45) Date of Patent: Jan

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(12) United States Patent (10) Patent No.: US 8,343,365 B2 Yoshibayashi (45) Date of Patent: Jan USOO83.43365B2 (12) United States Patent (10) Patent No.: US 8,343,365 B2 Yoshibayashi (45) Date of Patent: Jan. 1, 2013 (54) METHOD FOR PRODUCING COLOR FILTER 5,140,396 A 8, 1992 Needham et al. 5,510,215 A * 4/1996 Prince et al. ...................... 430.7 5,677,202 A * 10/1997 Hawkins et al. ................ 438/70 (75) Inventor: Mitsuji Yoshibayashi, Shizuoka-ken 5,689,318 A * 11/1997 Matsuyama et al. .......... 349/106 (JP) 6,720,119 B2 * 4/2004 Ohtsu et al. ............ 430.7 6,866,972 B2 * 3/2005 Ishino ............................... 430.7 (73) Assignee: FUJIFILM Corporation, Tokyo (JP) (Continued) (*) Notice: Subject to any disclaimer, the term of this FOREIGN PATENT DOCUMENTS patent is extended or adjusted under 35 JP 55-146406 A 11, 1980 U.S.C. 154(b) by 858 days. JP 61-041102 A 2, 1986 JP 5-323113 A 12/1993 (21) Appl. No.: 11/779,212 (Continued) (22) Filed: Jul. 17, 2007 OTHER PUBLICATIONS Prior Publication Data Communication, dated Sep. 24, 2012, issued in corresponding EP (65) Application No. 07014051.2, 5 pages. US 2008/OO176O7 A1 Jan. 24, 2008 Primary Examiner —Nadine Norton (30) Foreign Application Priority Data Assistant Examiner — Christopher Remavege (74) Attorney, Agent, or Firm — Sughrue Mion, PLLC Jul. 19, 2006 (JP) ................................. 2006-196622 Dec. 22, 2006 (JP) ................................. 2006-346108 (57) ABSTRACT (51) Int. C. The invention provides a color filter producing method that is B29D II/00 (2006.01) based on dry etching and makes it possible to produce a color HOIL 2L/00 (2006.01) filter which has fine and rectangular pixels and is excellent in (52) U.S. Cl. .................. 216/24; 216/2: 216/23: 216/37; flatness, and color filters produced by the method. The method is a color filter producing method of forming a first 216/38: 216/41; 216/58; 216/83: 438/65; colorant-containing layer on a Support, removing the first 438/66; 438/70 colorant-containing layer corresponding to a region where a (58) Field of Classification Search .................... 216/23, second colorant-containing layer is to be formed by dry etch 216/38, 50, 2, 24, 37, 41, 58,83; 438/65, ing, forming the second colorant-containing layer so as to be 438/66, 70 embedded into the layer-removed region, removing the first See application file for complete search history. and second colorant-containing layers corresponding to a References Cited region where a third colorant-containing layer is to be formed (56) by dry etching, forming the third colorant-containing layer so U.S. PATENT DOCUMENTS as to be embedded into the layer-removed region, and remov 4,182,647 A * 1/1980 Yoshihara et al. ............ 430,314 ing the colorant-containing layers laminated on other colo 4,534,620 A * 8/1985 Gale et al. ..................... 359,582 rant-containing layers. 4,777, 117 A 10, 1988 Murata et al. 5,059,500 A * 10, 1991 Needham et al. ................. 430,7 4 Claims, 6 Drawing Sheets 1O 13 NY US 8,343,365 B2 Page 2 U.S. PATENT DOCUMENTS FOREIGN PATENT DOCUMENTS 2003/0215574 A1* 11/2003 Ishino ........................ 427,385.5 JP 10-209410 A 8, 1998 2004/0197681 A1* 10/2004 Yaung ............................... 430,7 JP 2001-249218 A 9, 2001 2004/0246351 A1* 12, 2004 Hiatt et al. ... 348,272 2009/0104545 A1 4/2009 Chen et al. ........................ 430,7 * cited by examiner U.S. Patent Jan. 1, 2013 Sheet 2 of 6 US 8,343,365 B2 FIG 4 FIG 5 FIG. 6 U.S. Patent Jan. 1, 2013 Sheet 3 of 6 % Z23.2%2 / 2 2 . 2N2N2 U.S. Patent Jan. 1, 2013 Sheet 4 of 6 US 8,343,365 B2 FIG 10 7N FIG 11 SN %% FIG. 12 10 13 13 U.S. Patent Jan. 1, 2013 Sheet 5 of 6 US 8,343,365 B2 FIG 3 FIG. 14 13 S%SZS %3% SZSZS %.3% N2N2N FIG 15 14 eNe eNe e U.S. Patent Jan. 1, 2013 Sheet 6 of 6 US 8,343,365 B2 FIG 16 15 16 2 FIG 17 ZLZ52' US 8,343,365 B2 1. 2 METHOD FOR PRODUCING COLOR FILTER pickup elements has been particularly remarkable, and thus, it has been necessary to use a technique providing a high reso CROSS-REFERENCE TO RELATED lution below 2.0 um. Thus, in conventional photolithographic APPLICATION methods, the resolution thereofhas been approaching a limit. Apart from the above-mentioned color filter producing This application claims priority under 35 USC 119 from method using photolithography, a dry etching process has Japanese Patent Applications No. 2006-196622 and No. been hitherto known as a process effective for forming a 2006-346108, the disclosures of which are incorporated by thinner and finer pattern. The dry etching process has been reference herein. hitherto adopted as a process for forming a pattern with 10 respect to a thin film made of an evaporated colorant (see, for BACKGROUND OF THE INVENTION example, JP-A No. 55-146406). This process makes it pos 1. Field of the Invention sible to form a thin film which can have a thickness as small The present invention relates to a method for producing a as /2 or less of the thickness obtained by photolithography color filter, using a dry etching process. 15 and have spectral characteristics as good as those obtained by 2. Description of the Related Art photolithography. Furthermore, a pattern forming process As methods for manufacturing a color filter for use with a wherein photolithography is combined with a dry etching liquid crystal display device or a solid image pickup element, process has also been proposed (see, for example, JP-A No. dyeing methods, printing methods, electrodeposition meth 2001-249218). ods, and pigment dispersion methods are known. However, in the formation of a thin film by evaporation In the pigment dispersion method, the color filter is pro (vapor deposition), an evaporating device is unavoidably pol duced by a photolithographic method using a colorant-con luted. Thus, a large burden is imposed on the production of taining radiation-sensitive composition prepared by dispers color filters. Moreover, their pixels are made only of a pig ing a pigment in any one of various types of photosensitive ment or dye. For this reason, the adhesion of the pixels to an compositions. The color filter produced by this method is 25 underlying flattening layer oran upper layer is bad, and this is stable with respect to light, heat and the like since the pigment one of the reasons that the yield does not rise. is used. A high positional accuracy can be obtained in this Moreover, the color filter producing method based on dry method since patterning is performed by the photolitho etching has a problem in that when a second colorant-con graphic method, and accordingly, this method has widely taining layer is formed and etched, it is difficult to simulta been used as a method suitable for producing a color filter for 30 neously remove the coloring material of the second layer a color display with a large screen and high fineness. applied on the first layer and the coloring material of the In a case in which the color filter is produced by the pig second layer coated in a region where the first layer has been ment dispersion method, the radiation-sensitive composition removed. In the case of separately removing the coloring is first coated onto a glass Substrate by using, for example, a material of the second layer applied on the first layer and the spin coater or a roll coater and then dried, to thereby form a 35 coloring material of the second layer coated in the region coating film. Then, colored pixels are obtained by pattern where the first layer has been removed, there arise problems exposing and developing the thus-formed coating film. The in that the number of steps increases and costs increase. color filter can be obtained by repeating Such an operation as described above for each of the different colors. SUMMARY OF THE INVENTION As for the pigment dispersion method, a method which 40 uses a negative photosensitive composition comprising an The present invention has been made in view of the above alkali-soluble resin together with a photopolymerizable circumstances and provides a method for producing a color monomer and a photopolymerization initiator is proposed in filter. A first aspect of the present invention provides a method each of for example, Japanese Patent Application Laid-Open for producing a color filter, comprising: (JP-A) Nos. 2-181704, 2-199403, 5-273411 and 7-140654. 45 a first colorant-containing layer forming step (a) of form In recent years, it has been desired that color filters for solid ing a first colorant-containing layer over a Support; image pickup elements be made minuter and finer, and tech a photoresist layer forming step (b) of forming a photore niques using a dye have been suggested (see, for example, sist layer on the first colorant-containing layer, JP-A No. 6-75375). However, curable compositions which an image forming step (c) of removing the photoresist layer contain a dye have a problem in that various performances 50 in a region where a second colorant-containing layer different Such as light resistance, heat resistance, Solubility, and uni from the first colorant-containing layer is to be formed over form coating property are in general poorer than in composi the Support, thereby forming an image on the first colorant tions which contain a pigment. Moreover, when such a cur containing layer, able composition is used, in particular, for the production of a an etching step (d) of etching the first colorant-containing color filter for a solid image pickup element, the curable 55 layer in the region into the form of the image formed in the composition is required to provide a film thickness of 1.5um image forming step by dry etching; or less; therefore, it is necessary to add a large amount of a a photoresist layer removing step (e) of removing the pho colorant into the curable composition.
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