Positive-working photoresist composition

Abstract

Disclosed is a novel positive-working chemical-amplification photoresist composition used in the photolithographic patterning works in the manufacture of semiconductor devices capable of giving an excellently patterned resist layer with remarkably small film thickness reduction by the development treatment with an aqueous alkaline developer solution in the areas unexposed to patternwise exposure to light. Characteristically, the resinous ingredient in the composition, which is formulated in combination with a radiation-sensitive acid-generating agent and imparted with an increase in the solubility in an alkaline developer solution, is a ternary copolymeric resin consisting of the monomeric units of (a) hydroxystyrene units, (b) styrene units and (c) 1-alkylcyclohexyl (meth)acrylate units each in a specified molar fraction.

Dependencies are inferred from the claim text.