Patent ID: 7537880

Claim:
A polymer comprising recurring units having the general formulae (1a), (1b), and (1c): wherein R 1a , R 1b and R 1c are each independently hydrogen, fluorine or a straight or branched C 1 -C 4 alkyl or fluoroalkyl group, R 2a is hydrogen, —R 3 —CO 2 R 7 , or —R 3 —OR 7 , R 2c is a straight, branched or cyclic C 2 -C 20 fluoroalkyl group, R 3 is a divalent organic group which may contain fluorine, R 4 is a methylene group or oxygen atom, R 5 is hydrogen, methyl or trifluoromethyl, R 6 is a straight, branched or cyclic C 2 -C 20 fluoroalkyl group, R 7 is hydrogen, a straight, branched or cyclic C 1 -C 20 alkyl or fluoroalkyl group, acid labile group or adhesive group, the subscripts “a,” “b” and “c” are numbers satisfying 0≦a<1, 0<b<1, 0≦c<1, and 0<a+b+c≦1, said polymer having a weight average molecular weight of 1,000 to 500,000.