Synthesis and lithographic characterization of a novel organosilicon novolac resin.

A novel terpolymer of o-cresol, p-trimethylsilylmethyl phenol and formaldehyde was synthesized. With a 9.7wt% Si content, the polymer displayed an RIE resistance 10 times greater than hard-baked HPR 204. The organosilicon novolac was employed as a base resin component of bilevel resist systems for both photo and electron-beam lithography. The low molecular weight polymer behaves as a positive resist when mixed with a dissolution inhibitor. In photo-lithography, the dissolution inhibitor was a diazoquinone based chemical which was converted to an acidic species during irradiation. In electron-beam lithography, poly(2-methyl-1 pentene sulfone) (PMPS), which depolymerizes upon electron-irradiation, functioned as the dissolution inhibitor. When the silylated novolac was used as a photoresist, coded 0.9microns line/space patterns were obtained with a sensitivity of ~120 mj/cm(2). When employed as an electron-beam resist coded 0.75microns line/space patterns were resolved with a dose of 8muC/cm(2).