Patterning process and resist composition

摘要

A negative pattern is formed by coating a resist composition onto a substrate, the resist composition comprising a polymer comprising recurring units having an acid labile group-substituted hydroxyl group, an acid generator, an onium salt of perfluoroalkyl ether carboxylic acid, and an organic solvent, prebaking, exposing, baking, and developing in an organic solvent such that the unexposed region of film is dissolved away and the exposed region of film is not dissolved. In image formation via positive/negative reversal by organic solvent development, the resist film is characterized by a high dissolution contrast between the unexposed and exposed regions.

主权项

1. A pattern forming process comprising the steps of:
applying a resist composition onto a substrate, the resist composition comprising a polymer comprising recurring units having a hydroxyl group substituted with an acid labile group and an acid generator, or a polymer comprising recurring units having a hydroxyl group substituted with an acid labile group and recurring units capable of generating an acid upon exposure, a sulfonium or iodonium salt of perfluoroalkyl ether carboxylic acid, and an organic solvent, prebaking the composition to form a resist film, exposing 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 film is dissolved away and the exposed region of film is not dissolved, wherein said sulfonium or iodonium salt of perfluoroalkyl ether carboxylic acid is a salt (Q1) or Q2) having the general formula (2):wherein R101a, R101b and R101c are each independently a straight, branched or cyclic C1-C12 alkyl, alkenyl, oxoalkyl or oxoalkenyl group, C6-C20 aryl group, or C7-C12 aralkyl or aryloxoalkyl group, in which some or all hydrogen atoms may be substituted by ether, ester, carbonyl, carbonate, hydroxyl, carboxyl, halogen, cyano, amino, amide, nitro, sultone, sulfonic acid ester, sulfone groups, or substituent groups having sulfonium salt, or R101b and R101c may bond together to form a ring with the sulfur atom to which they are attached, R101b and R101c each are a C1-C6 alkylene group when they form a ring,
R101d and R101e each are a C6-C20 aryl group which may contain a straight, branched or cyclic C1-C6 alkyl or alkoxy radical, or R101d and R101e may bond together to form a ring with the iodine atom to which they are attached, and R14—COO− is selected from the group consisting of the following formulae: