Positive-working photoresist composition comprising a novolac resin made in butyrolactone as a solvent

摘要

Proposed is an improved positive-working photoresist composition for use in the photolithographic patterning works for the manufacture of semiconductor devices, which is capable of giving a patterned resist layer on a substrate surface having excellent resolution and heat resistance without formation of scum in the development treatment. The photoresist composition comprises: (a) an alkali-soluble novolac resin as a film-forming ingredient and (b) a naphthoquinone diazide group-containing compound as a photosensitizing ingredient, of which the novolac resin is a condensation product of a phenolic compound and an aldehyde compound, the condensation reaction being undertaken in a solvent system containing, in addition to water, gamma -butyrolactone or a combination of gamma -butyrolactone and a propyleneglycol monoalkyl ether in a limited proportion.