Formation of Fine Pattern by Reaction Development Patterning Using Photo-Base Generator and Acidic Developers

Abstract

Reaction development patterning (RDP) applicable to polyacetals was investigated by using inverse acid-base condition, namely, photo-base generator and acidic developers. Polyacetal films composed of polyacetals, O-phenylacetyl 2-acetonaphthone oxime as a photo-base generator and benzophenone as a photosensitizer gave positive-tone patterns after irradiation with an ultrahigh-pressure mercury lamp and successive dipping in developer containing carboxylic acid, methanesulfonic acid or sulfuric acid. Reduction in thickness at the unexposed area was inhibited by incorporation of trifluoromethyl groups to polyacetals.