Patent ID: 7575853

Claim:
A thin film pattern forming method comprising: a step of forming a first thin film on a substrate; a step of forming a resist pattern, the resist pattern having a two-layer structure including a first resist layer and a second resist layer which are composed of respectively different insulating materials, a step of forming an undercut in the resist pattern; a step of forming a covering layer that covers the first thin film and the resist pattern including surfaces of the undercut of the resist pattern so as to form a coated resist pattern, the covering layer being a soluble layer; and a step of forming the first thin film pattern by selectively removing the first thin film by dry etching using the resist pattern as a mask, wherein the formation of the undercut forms a vertical shape of the resist pattern in which a lower part of the resist pattern is narrower than an upper part of the resist pattern, and the covering layer is provided on the whole surface of the resist pattern and is formed so as to generally have the shape of the undercut in that a lower part of the coated resist pattern corresponding to the lower part of the resist pattern is narrower than an upper part of the coated resist pattern corresponding to the upper part of the resist pattern.