Patent ID: 8808966

Claim:
A positive resist composition comprising as a base resin a polymer having carboxyl groups whose hydrogen is substituted by an acid labile group having the general formula (1): wherein A is —(CR 2 2 ) m —, B is —(CR 5 2 ) n —, R 2 and R 5 are each independently hydrogen or a straight, branched or cyclic C 1 -C 6 alkyl group, or R 2 groups or R 5 groups may bond together to form a C 3 -C 9 ring with the carbon atom to which they are attached, m and n each are 1 or 2, R 3 is a straight, branched or cyclic C 1 -C 12 alkyl, C 2 -C 12 alkenyl, C 2 -C 12 alkynyl or C 6 -C 10 aryl group which may have an oxygen or sulfur atom, R 6 is selected from the class consisting of C 1 -C 4 alkyl, alkoxy, alkanoyl, alkoxycarbonyl, hydroxyl, nitro, C 6 -C 10 aryl, halogen, and cyano, and p is an integer of 0 to 4.