Polymer suitable for photoresist compositions

A cyano containing copolymer comprising at least one ethylenic unit of structure 1 containing at least one cyano functionality, and at least one cyclic unit of structure 2, where structure 1 is

• where, R1-R4 are independently hydrogen, alkyl, O-alkyl, alkyl ester, perfluoroalkyl ester, carboxylic acid, alkylcarbonyl, carboxylate, cyano(CN), fluoroalkyl, acid or base labile group, alkylsulfonyl, sulfonate, sulfonamide, alkylsulfonamide, providing that at least one of R1-R4 is cyano, and where structure 2 is
• where R5-R14 are independently hydrogen, (C1-C6)alkyl, halogen, carboxylic acid, (C1-C10)alkylOCOalkyl, cyano(CN), (C1-C10) secondary or tertiary carboxylate, substituted pinacol, R7 and R8 may be linked to form a cyclic non-aromatic structure, fluoroalkyl, W(CF3)2OH, where W is (C1-C6)alkyl or (C1-C6)alkyl ether, or an acid or base labile group,
• R15 and R16 are hydrogen or (C1-C4)alkyl,
• and m is 0-3.
• and further providing that the copolymer contains an acid or base labile group connected directly to the polymer or through a connecting group which is removed in the presence of an acid or base to give a polymer that is alkali soluble.