Patent ID: 6849375

Claim:
A photoresist polymer comprising a repeating unit selected from the group consisting of Formula 2 and Formula 3; wherein R 1 is selected from the group consisting of H, halogen, (C 1 -C 20 ) alkyl, (C 1 -C 20 ) alkyl with at least one halogen substituent, (C 1 -C 20 ) alkyl containing at least one of an ether group (—O—) and an ester group, (C 1 -C 20 ) alkyl with at least one halogen substituent and containing at least one of an ether group and an ester group, and —COOR′; R 2 , R 3 , R 5 and R 6 are individually selected from the group consisting of H, halogen, (C 1 -C 20 ) alkyl, (C 1 -C 20 ) alkyl with at least one halogen substituent, (C 1 -C 20 ) alkyl containing at least one of an ether group and an ester group and (C 1 -C 20 ) alkyl with at least one halogen substituent and containing at least of one of an ether group and an ester group; R′, R 4 and R 7 are individually acid labile protecting groups, wherein R 4 is not t-butyl; X 1 and X 2 are individually selected from the group consisting of (C 1 -C 10 ) alkylene, O and S; Y 1 , Y 2 , Y 3 , Y 4 , Y 5 , Y 6 , Z 1 and Z 2 are individually selected from the group consisting of halogen, an alkyl partially substituted with halogen, and an alkyl wholly substituted with halogen; m and n are individually integers ranging from 0 to 2; the ratio a:b:c of Formula 2 falls within the range 1-50 mol %:present and in an amount up to and including 90 mol %: 0-9° mol %; and the ratio a:b:c of Formula 3 falls within the range 1-50 mol %=0-90 mol %:0-90 mol %, wherein at least one of b and c must be present.