Patent ID: 7208260

Claim:
A photoresist copolymer derived from a mixture of monomers comprising: (a) two or more alicyclic olefin derivatives, each having the formula: wherein k and n is independently 1 or 2; p is an integer from 0 to 5; R 5 and R 6 are independently hydrogen or methyl; and R 1 , R 2 , R 3 , and R 4 individually represent hydrogen, straight or branched C 1-10 alkyl, straight or branched C 1-10 ester, straight or branched C 1-10 ketone, straight or branched C 1-10 carboxylic acid, straight or branched C 1-10 acetal, straight or branched C 1-10 alkyl including at least one hydroxyl group, straight or branched C 1-10 ester including at least one hydroxyl group, straight or branched C 1-10 ketone including at least one hydroxyl group, straight or branched C 1-10 carboxylic acid including at least one hydroxyl group, and straight or branched C 1-10 acetal including at least one hydroxyl group, and (b) a cross-linking monomer of the formula: wherein each of R′ and R″ is independently hydrogen or methyl; m is an integer from 1 to 10; and R is straight or branched C 1-10 alkyl, optionally comprising an ester, a ketone, a carboxylic acid, an acetal, a hydroxyl group or a combination thereof.