Patent ID: 7169531

Claim:
A polymer comprising repeating units of the following general formula: wherein: each ofR1–R5, independently of each other, is H, F or a fluorine-substituted alkyl group having preferably 1–6 carbon atoms; R6 is an acid-labile group, including tert-alkyl ester, tert-butoxycarbonyloxy, tert-butoxycarbonylmethyl, tetrahydrofuranyl, tetrahydropyranyl, tert-butyl ether, lactone or acetal groups, and at least one of the hydrogen atoms contained in the acid-labile groups is substituted with fluorine atoms; Y is a straight-chain or branched alkyl group including 1 to 6 carbon atoms, the straight-chain or branched alkyl group being at least partially fluorinated and including functional groups having acetal, ketal, carboxyl groups, ether groups, a hetero atom and/or a carbonyl group; m is 0 or 1; k is 0 or an integer from 1 to 3; and at least two of R1–R3 include at least one of a fluorine atom and a fluoroalkyl group.