PHOTOSENSITIVE POLYMER HAVING CYCLIC BACKBONE AND PHOTORESIST COMPOSITION CONTAINING THE SAME

摘要

PROBLEM TO BE SOLVED: To obtain a photosensitive polymer comprising a specific tetrapolymer and having a cyclic backbone so that the resistance to dry etching can sufficiently be ensured used for a chemical amplification type resist. SOLUTION: This photosensitive polymer is used for a chemical amplification type photoresist and is represented by the formula [R1 is a 7-20C alicyclic hydrocarbon; R2 and R4 are each a 1-7C aliphatic hydrocarbon; R3 and R5 are each H or methyl; R6 is H or 2-hydroxyethyl; p/(p+q+r+s)=0.1-0.5; q/(p+q+r+ s)=0.1-0.5; r/(p+q+r+s)=0.0-0.5; s/(p+q+r+s)=0.01-0.5; (p+q+r+s)=1.0]. The polymer preferably has 5,000-100,000 weight-average molecular weight. A resist composition is preferably composed of the polymer (A), (B) a photoacid generator (PAG) (e.g. a triarylphosphonium salt) and further (C) an organic base. The amounts of the contained components based on the weight of the component A are preferably 1-15 wt.% of the component B and 0.01-2.0 wt.% of the component C.