Molecular Structure of Plasma-polymerized Methyl Methacrylate and Evaluation as a Resist

Abstract

Plasma polymerization of methyl methacrylate was performed in a down stream of carrier gas glow discharge. The effects of carrier gases on growth rate and etching rate of the film were studied. IR, ESCA and NMR measurements were carried out for the film and the molecular structure and reaction mechanism were discussed. The films were also delineated by the electron beam and X-ray and served for a plasma etching. Their qualities as a resist were evaluated.
In the case of inert carrier gases, radical reactions were expected to be a predominant mechanism and the molecular structures resembled a conventional polymer. For the carrier of reactive gases like oxygen, ionic reactions were observed and the molecular structures did not resemble the conventional one. In the case of dry etching development, the film as a resist showed higher sensitivity than that of conventional polymer. However, the sensitivity was still low for the practical use.