Patent ID: 9551932
Date: 2017-01-24
CPC Classifications: G03F

Claim:
1. A pattern forming process comprising the steps of: applying a resist composition comprising a polymer and an optional acid generator onto a substrate, prebaking the composition to form a resist film, exposing a selected region of the resist film to high-energy radiation, baking, and developing the exposed film in an organic solvent-based developer to form a negative pattern wherein the unexposed region of resist film is dissolved away and the exposed region of resist film is not dissolved, said polymer consisting of: recurring units (a1) having an acid labile group of formula (1a), represented by the general formula (1): wherein R 1 is methyl, and the broken line designates a valence bond, recurring units (a2) represented by the general formula (2) and recurring units of at least one type selected from recurring units (b1) to (b4) represented by the general formula (3): wherein R 10 is hydrogen or methyl, R 11 is an acid labile group other than formula (1a), and X 1 is a single bond, phenylene, naphthylene, or —C(═O)—O—R 12 — wherein R 12 is a straight, branched or cyclic C 1 -C 10 alkylene group which may contain an ether radical, ester radical, lactone ring or hydroxyl radical, or a phenylene or naphthylene group, wherein R 13 and R 16 each are hydrogen or methyl; R 14 is a di- to pentavalent, straight, branched or cyclic C 1 -C 16 aliphatic hydrocarbon group which may contain an ether or ester radical; R 15 and R 17 each are an acid labile group; R 18 to R 21 and R 22 to R 25 are each independently hydrogen, cyano, a straight, branched or cyclic C 1 -C 6 alkyl group, alkoxycarbonyl, or a group having an ether radical or lactone ring, at least one of R 18 to R 21 and R 22 to R 25 has a hydroxyl group substituted with an acid labile group; m is an integer of 1 to 4, n is 0 or 1; recurring units (c) derived from a monomer having an adhesive group, but not an acid labile group, the adhesive group being selected from the group consisting of a hydroxyl, cyano, carbonyl, ester, ether, lactone ring, carboxyl, carboxylic anhydride, sulfonic acid ester, disulfone and carbonate group; recurring units of at least one type selected from recurring units (d1), (d2) and (d3) represented by the general formula: wherein R 020 , R 024 and R 028 each are hydrogen or methyl, R 021 is a single bond, phenylene, —O—R 033 —, or —C(═O)—Y—R 033 —, Y is oxygen or NH, R 033 is a straight, branched or cyclic C 1 -C 6 alkylene group, alkenylene group or phenylene group, which may contain a carbonyl (—CO—), ester (—COO—), ether (—O—) or hydroxyl radical, R 022 , R 023 , R 025 , R 026 , R 027 , R 029 , R 030 , and R 031 are each independently a straight, branched or cyclic C 1 -C 12 alkyl group which may contain a carbonyl, ester or ether radical, or a C 6 -C 12 aryl, C 7 -C 20 aralkyl, or thiophenyl group, Z 1 is a single bond, methylene, ethylene, phenylene, fluorophenylene, —O—R 032 —, or —C(═O)—Z 2 —R 032 —, Z 2 is oxygen or NH, R 032 is a straight, branched or cyclic C 1 -C 6 alkylene group, alkenylene group or phenylene group, which may contain a carbonyl, ester, ether or hydroxyl radical, M − is a non-nucleophilic counter ion; recurring units (e) having a non-leaving hydrocarbon group; and recurring units (f) having an oxirane or oxetane ring, wherein 0<a1<1.0, 0≦a2<1.0, 0≦b1<1.0, 0≦b2<1.0, 0≦b3<1.0, 0≦b4<1.0, 0≦a2+b1+b2+b3+b4<1.0, 0<c<1.0, 0≦d1≦0.3, 0≦d2≦0.3, 0≦d3≦0.3, 0≦d1+d2+d3≦0.3, 0≦e≦0.4, and 0≦f≦0.6.