Patent ID: 6916543

Claim:
A copolymer comprising: at least one Structure (I) first repeating unit comprising one or more repeating units selected from the group consisting of units represented by Structure (IA), Structure (IB) and Structure (1C) wherein each R 1 is independently a selected from the group consisting of hydrogen atom or a methyl group; R 3 is selected from the group consisting of a linear, branched and cyclic alkyl or alicyclic group having 1 to 20 carbon atoms; m is an integer from about 2 to about 10; each R 4 is independently be selected from the group consisting of H and Structure (II), wherein R 5 , R 6 and R 7 are each independently selected from the group consisting of a linear, branched or cyclic alkyl, alicyclic and fluoroalkyl group having 1 to 20 carbon atoms; and each R 2 is independently selected from the group consisting of (a) a linear, branched or cyclic alkyl unsubstituted or substituted alicyclic group, having 1 to 20 carbon atoms; (b) A linear, branched or cyclic fluoroalkyl or fluorine substituted alicyclic group having 1 to 20 carbon atoms; and (c) a polar group selected from the group consisting of (1) (CH 2 ) n —OR 8 , where n is an integer from about 2 to about10 and R 8 is selected from the group consisting of H, R 3 group and α-alkoxy alkyl group; R 3 is a linear, branched or cyclic alkyl or alicyclic group having 1 to 20 carbon atoms; (2) (CH 2 ) n —(C═O)—OR 9 , where n is an integer from about 2 to about 10 and R 9 is selected from the group consisting of H, R 3 group and an acid sensitive protecting group; R 3 is a linear, branched or cyclic alkyl or alicyclic group having 1 to 20 carbon atoms; (3) (CH 2 ) n —C(CF 3 )R 10 —OR 11 , where n is an integer from about 2 to about 10 and R 10 is selected from the group consisting of H, fluoromethyl, difluoromethyl, and trifluoromethyl and R 11 is selected from the group consisting of H and an R 3 alkyl group; and (4) (CH 2 ) n —O—(C═O)R 3 , where n is an integer from about 2 to about 10; and R 3 is a linear, branched or cyclic alkyl or alicyclic group having 1 to 20 carbon atoms; and a second repeating unit represented by Structure (III) wherein R 1 has the same meaning as defined above and R 12 is an acid labile group, with the proviso that when Structure (IA) is present in the copolymer and R 12 is t-Bu, an additional repeating unit having Structure (IV), or Structure (VI), or a repeating unit derived from an ethylenically unsaturated, polymerizable silicon compound different from Structures (IA), (IB), and (IC), as defined hereinafter, must be present, and where Structure (IV) is as follows: wherein R 1 has the same meaning as defined above and R 13 is selected from the group consisting of the following structures (Va-Vg) and Structure (VI) is where R 1 has the meaning as defined above.