Synthesis of copolymers containing 3-hydroxycyclohexyl methacrylate and their application as ArF excimer laser resists

Abstract

Copolymers containing 3-hydroxycyclohexyl methacrylate (HCMA) were synthesized as a base polymer for ArF excimer laser lithography. The dry-etching rates of these polymers for CF4:CHF3 mixed gas were 1.1-1.2 times that of a novolac-based resist. The adhesion properties of the polymers were also studied by estimating the work of adhesion. When the content of the HCMA unit in the polymer exceeds 60 mol%, the work of adhesion of the resist is similar to those of polyvinylphenol (PVP)-based photoresists. A 0.19 mu m pattern profile was obtained using a resist based on the terpolymer containing HCMA and the conventional developer, 2.38 wt% tetramethylammonium hydroxide (TMAH) aqueous solution. (C) 1998 Elsevier Science Ltd. All rights reserved.