Patent ID: 7175960

Claim:
A positive resist composition comprising as a base resin a mixture of 100 parts by weight of an alkali-soluble novolak resin comprising recurring units of the structural formula (1) and 1 to 20 parts by weight of a phenolic compound of the structural formula (2), wherein a mixture of the alkali-soluble novolak resin and the phenolic compound is subjected to esterification with a 1,2-naphthoquinonediazidosulfonic acid compound whereby the hydrogen atoms of all hydroxyl groups are substituted in a proportion of 0.03 to 0.05 mol per hydrogen atom with 1,2-naphthoquinonediazidosulfonyl ester groups, wherein m is an integer of 0 to 3, wherein R 1 to R 8 are each independently hydrogen, a straight, branched or cyclic alkyl group having 1 to 6 carbon atoms, or a straight, branched or cyclic alkoxyl group having 1 to 6 carbon atoms, R 9 to R 11 are each independently hydrogen or a straight, branched or cyclic alkyl group having 1 to 6 carbon atoms, R 10 and R 11 , taken together, may form a ring with the carbon atom to which they are bonded, R 2 is hydrogen, a straight alkyl group having 1 to 6 carbon atoms, or a group of the formula (3): wherein R 13 and R 14 are each independently hydrogen, a straight, branched or cyclic alkyl group having 1 to 6 carbon atoms, or a straight, branched or cyclic alkoxyl group having 1 to 6 carbon atoms, d is an integer of 1 to 3, R 12 and R 9 , taken together, may form a ring of 3 to 6 carbon atoms with the carbon atom to which they are bonded, a and b each are an integer of 1 to 3, c is an integer of 0 to 3, and n is an integer of 0 to 3.