A highly etch resistant, negative resist for deep-UV and electron beam lithography

Highly sensitive resists have been developed from a combination of silsesquioxanes, acid photogenerators, and phenolic resins. The resist forms negative images and is developable with aqueous base. Both electron beam and deep-uv optical sensitivity was observed. The films displayed exceptionally high oxygen reactive ion etch resistance. Bilayer systems were developed with this resist as the imaging layer with either polyimide or hard baked novolac as the planarizing layer. Improved optical resists for single layer application have been obtained by using poly(4-hydroxystyrene) derivatives as the matrix resin.