Patent ID: 8703384

Claim:
A positive resist composition comprising (A) a polymer comprising recurring units of a structure adapted to generate an acid in response to high-energy radiation selected from UV, deep UV, electron beam, x-ray, excimer laser, γ-ray and synchrotron radiation, having the general formula (1-1) or (1-2) and acid labile units, the polymer having an alkali solubility that increases under the action of an acid, and (B) a sulfonium salt having the general formula (2-1) or (2-2), wherein R 1 is hydrogen or methyl, R 2 is hydrogen or trifluoromethyl, R 3 , R 4 , and R 5 are each independently a substituted or unsubstituted, straight, branched or cyclic C 1 -C 10 alkyl, alkenyl or oxoalkyl group, or substituted or unsubstituted C 6 -C 18 aryl, aralkyl or aryloxoalkyl group, any two of R 3 , R 4 , and R 5 may bond together to form a ring with the sulfur atom, R 6 and R 7 are each independently a substituted or unsubstituted C 6 -C 18 aryl group, wherein R 8 is hydrogen or trifluoromethyl, R 9 is a straight, branched or cyclic, monovalent hydrocarbon group of 4 to 30 carbon atoms which may contain a heteroatom, and n is an integer of 1 to 4.