Vacuum-Ultraviolet Light Sources and Their Applications for Processings. Thin Film Preparation Using Vacuum Ultraviolet Rare Gas Excimer Lamps.

Abstract

Rare gas excimer lamps using dielectric-barrier discharge are a new type of compact and high-efficient light source for vacuum ultraviolet wavelength region. Since the lamps produce incoherent and quasi-continuous radiation, uniform processing over large sample areas is expected to be possible without thermal effects and speckling or interference fringes. The purpose of this paper is to exploit a new technique of material processing by use of the newly developed incoherent rare gas excimer lamps. We will describe some findings obtained by applying the excimer lamps to preparation of silica thin films. A photochemical vapor deposition using a Xe2 excimer lamp has made it possible to prepare silica films by means of a single precursor process from tetraethoxyorthosilicate (TEOS) at room temperature. Transparent SiO2 thin films were obtained with a deposition rate of 0.9nm/min. The refractive index was 1.476 at 632.8nm and the surface roughness reached 0.2nm-rms. These findings indicate that the VUV excimer lamp CVD is a promising method for preparing smooth and fine thickness-controllable films of SiO2 at room temperature. We confirmed that, this technique provides a very promising photo-quantum process for the fabrication of semiconductors and opt-electronic devices, and others.