セラミックスのフォトエッチングのための環化ポリブタジエンレジスト膜の形成条件

Abstract

This paper describes the effects of conditions, such as prebaking length, exposure energy, and postbaking temperature, on polybutadiene resist film formation, when obtaining high chemical resistance to hot phosphoric acid etchant. After alumina ceramic was etched at temperatures from 260°C to 320°C, we measured the change in resist thickness, resist film breakdown ratio, and etch factors. Polybutadiene molecules are cross-linked both photolytically and pyrolytically, so postbaking critically affects the enhancing of the resist's thermal and chemical stability. Prebaking at 80°C for 30min, exposure at 7-9mJ/cm2, and postbaking at 300°C for 30min yielded a highly chemically resistant, strongly adhesive, optimal resist film. The etch factor increased with increasing etching temperature, probably due to decreased acid viscosity, becoming about 2 at an etching temperature of 300°C. At higher etching temperatures, however, the etch factor decreased and the resist breakdown ratio increased, indicating that the applicable maximum etching temperature was 300°C for the polybutadiene resist.