(Meth)acrylate derivative, polymer and photoresist composition having lactone structure, and method for forming pattern by using it

Abstract

There are here disclosed a photoresist material for lithography using a light of 220 nm or less which comprises at least a polymer represented by the following formula (2) and a photo-acid generator for generating an acid by exposure: wherein R1, R2, R3 and R5 are each a hydrogen atom or a methyl group; R4 is an acid-labile group, an alicyclic hydrocarbon group having 7 to 13 carbon atoms, which has an acid labile group, an alicyclic hydrocarbon group having 7 to 13 carbon atoms, which has a carboxyl group, or a hydrocarbon group having 3 to 13 carbon atoms, which has an epoxy group; R6 is a hydrogen atom, a hydrocarbon group having 1 to 12 carbon atoms, or an alicyclic hydrocarbon group having 7 to 13 carbon atoms, which has a carboxyl group; x, y and z are optional values which meet x+y+z=1, 0<x≦1, 0≦y<1 and 0≦z<1; and a weight-average molecular weight of the polymer is in the range of 2000 to 200000, and a resin having a (meth)acrylate unit of an alicyclic lactone structure represented by the formula (3): wherein R8 is a hydrogen atom or a methyl group, and R9 is a hydrocarbon group of 7 to 16 carbon atoms having an alicyclic lactone structure.

Dependencies are inferred from the claim text.