Patterning process and resist composition

摘要

A negative pattern is formed by coating a resist composition comprising a polymer comprising recurring units having a tertiary ester type acid labile group having a plurality of methyl or ethyl groups on alicycle and an acid generator onto a substrate, prebaking, exposing to high-energy radiation, baking, and developing in an organic solvent developer so that the unexposed region of resist film is dissolved away and the exposed region of resist film is not dissolved. The resist composition exhibits a high dissolution contrast during organic solvent development and forms a fine hole or trench pattern of dimensional uniformity.

主权项

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 comprising recurring units (a1) having the general formula (1):wherein R1 is hydrogen or methyl, R2 is a straight, branched or cyclic C1-C10 alkyl group, R3 is methyl or ethyl, X1 is a C1-C10 alkylene group which may have an ether radical, ester radical, lactone ring or hydroxyl radical, or C6-C10 arylene group, X2 is methylene or ethylene, k1 is 0 or 1, k2 is an integer of 2 to 6, and 0