Silicon-containing novolak resin and resist material and pattern forming method using same

摘要

Disclosed is a novel novolak resin comprising structural units having a trimethylsilyl group. A resist material highly resistive to dry etching is obtained by adding a photosensitive diazo compound to this novolak resin. The resist material is useful in various lithography methods to form a positive resist pattern. This resist material is used in a pattern forming method of a two-layer type, in which a fine pattern is formed in a thin film of the resist material by lithography and then transferred into an underlying thick organic polymer layer by dry etching of the underlying layer with the resist pattern as mask. Curing of the resist pattern by irradiation with deep UV rays is effective for further improvement in the precision of the transferred pattern.