PHOTORESIST PATTERN TRIMMING COMPOSITIONS AND METHODS OF TRIMMING PHOTORESIST PATTERNS
Photoresist pattern trimming compositions comprise: a polymer comprising as polymerized units a monomer comprising an acid-decomposable group, the decomposition of which group forms a carboxylic acid group on the polymer; a non-polymeric acid or a non-polymeric thermal acid generator; and an organic-based solvent system comprising one or more organic solvents. Methods of trimming photoresist patterns involve applying such pattern trimming compositions to a photoresist pattern that is formed from a photoresist composition comprising a photoacid generator and a polymer comprising acid-decomposable groups. The photoresist pattern trimming compositions and pattern formation methods find particular use in the formation of fine lithographic patterns in the semiconductor manufacturing industry.
1 . A photoresist pattern trimming composition, comprising:
a polymer comprising as polymerized units a monomer comprising an acid-decomposable group, the decomposition of which group forms a carboxylic acid group on the polymer;
a non-polymeric acid or a non-polymeric thermal acid generator; and
an organic-based solvent system comprising one or more organic solvents.
2 . The photoresist pattern trimming composition of claim 1 , wherein the acid-decomposable group is a tertiary alkyl ester.
3 . The photoresist pattern trimming composition of claim 1 , wherein the acid-decomposable group is an acetal group.
4 . The photoresist pattern trimming composition of claim 1 , wherein the polymer further comprises as polymerized units a monomer comprising (i) a fluoroalcohol group, or (ii) an acid-decomposable group, the decomposition of which group forms a fluoroalcohol group on the polymer.
5 . The photoresist pattern trimming composition of any of claim 1 , wherein the polymer further comprises as polymerized units a monomer which is an unsubstituted C1-C10 alkyl (meth)acrylate monomer.
6 . The photoresist pattern trimming composition of any of claim 1 , wherein the combined content of all polymerized units of monomers comprising an acid-decomposable group, the decomposition of which group forms a carboxylic acid group on the polymer, is from 30 to 100 mole % based on total polymerized units of the polymer.
7 . The photoresist pattern trimming composition of any of claim 1 , wherein the polymer is free of acid groups.
8 . The photoresist pattern trimming composition of any of claim 1 , wherein the organic-based solvent system comprises a monoether.
9 . The photoresist pattern trimming composition of claim 8 , wherein the organic-based solvent system further comprises an alcohol and/or an ester.
10 . A method of trimming a photoresist pattern, comprising:
(a) providing a semiconductor substrate;
(b) forming a photoresist pattern over the semiconductor substrate, wherein the photoresist pattern is formed from a photoresist composition comprising a photoacid generator and a polymer comprising acid-decomposable groups;
(c) coating a pattern trimming composition of any claim 1 over the photoresist pattern;
(d) heating the coated photoresist pattern; and
(e) rinsing the coated and heated photoresist pattern with a rinsing agent to remove a surface region of the photoresist pattern.
11 . The method of claim 10 , wherein the rinsing agent is an aqueous tetramethylammonium hydroxide solution.
12 . The method of claim 10 , wherein the photoresist pattern is formed by KrF or EUV lithography.
13 . The method of claim 10 , wherein the acid-decomposable group is a tertiary alkyl ester.
14 . The method of claim 10 , wherein the acid-decomposable group is an acetal group.
15 . The method of claim 10 , wherein the polymer further comprises as polymerized units a monomer comprising (i) a fluoroalcohol group, or (ii) an acid-decomposable group, the decomposition of which group forms a fluoroalcohol group on the polymer.
16 . The method of claim 10 , wherein the polymer further comprises as polymerized units a monomer which is an unsubstituted C1-C10 alkyl (meth)acrylate monomer.
17 . The method of claim 10 , wherein the combined content of all polymerized units of monomers comprising an acid-decomposable group, the decomposition of which group forms a carboxylic acid group on the polymer, is from 30 to 100 mole % based on total polymerized units of the polymer.
18 . The method of claim 10 , wherein the polymer is free of acid groups.
19 . The method of claim 10 , wherein the organic-based solvent system comprises a monoether.
20 . The method of claim 10 , wherein the organic-based solvent system further comprises an alcohol and/or an ester.