Patent ID: 7083893

Claim:
A photoresist polymer consisting of a repeating unit represented by Formula 1: wherein X 1 and X 2 individually are selected from the group consisting of CH 2 , CH 2 CH 2 , O and S; R 1 is selected from the group consisting of acid labile protecting group, C 1 –C 20 alkyl and C 1 –C 20 cycloalkyl; R 2 is H, C 1 –C 20 alkyl, C 5 –C 10 cycloalkyl, or C 5 –C 10 cycloalkyl including an ether group, and C 5 –C 10 cycloalkyl including an ester group; m is an integer ranging from 0 to 2, n is an integer of 0 or 1; and the relative ratio of a:b:c is in the range of 50 mol %:20˜50 mol %:0˜30 mol %.