Patent ID: 9519213
Filing Date: 2016-12-13
CPC Classification: G03F

Claim Text:
1. A process for forming a negative pattern, comprising the steps of coating a resist composition comprising (A) a polymer having an acid labile group, adapted to change its polarity under the action of acid, (B) a photoacid generator, and (C) an organic solvent onto a substrate, baking the coating to form a resist film, exposing the resist film to high-energy radiation to define exposed and unexposed regions, baking, and developing the resist film in a developer selected from the group consisting of ketones and esters to selectively dissolve the unexposed region of resist film, said photoacid generator (B) having the general formula (1): wherein R 1 is a straight, branched or cyclic, monovalent hydrocarbon group of 1 to 50 carbon atoms which may contain a heteroatom, R 2 , R 3 and R 4 are each independently a substituted or unsubstituted, straight or branched C 1 -C 10 alkyl, alkenyl or oxoalkyl group or a substituted or unsubstituted C 6 -C 18 aryl, aralkyl or aryloxoalkyl group, or at least two of R 2 , R 3 and R 4 may bond together to form a ring with the sulfur atom, and said polymer (A) comprises recurring units having the general formula (2): wherein R 5 is hydrogen or methyl, R 6 is a straight, branched or cyclic, divalent aliphatic hydrocarbon group of 2 to 16 carbon atoms which may contain an ether or ester bond, R 7 is tert-pentyl or neopentyl, m is 0 or 1, and n is 1 or 2.