| abstract |
A positive resist composition comprises (A) a resin component which becomes soluble in an alkaline developer under the action of an acid and (B) an acid generator. Resin component (A) is a polymer comprising recurring units of formula (1) wherein R 1 is H, CH 2 or CF 3 , R 2 is an acid labile group, R 3 is H or CO 2 CH 3 , X is O, S, CH 2 or CH 2 CH 2 , 0.01≦a<1 and 0.01≦b<1. When processed by ArF lithography, the composition forms a pattern with a satisfactory mask fidelity and a minimal LWR. |