J. Phys. IV France 09 (1999) Pr8-877-Pr8-883
Unveiling the magic of H2S on the CVD-Al2O3 coatingT. Oshika1, A. Nishiyama1, K. Nakaso2, M. Shimada2 and K. Okuyama2
1 Mitsubishi Materials Corporation, Central Research Institute, 1-297 Kitabukuro-cho, Omiya, Saitama 330-8508, Japan
2 Department of Chemical Engineering, Faculty of Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8527, Japan
The role of H2S in the mechanism of CVD-Al2O3 coating was investigated by measuring particles suspended in the gas phase with an optical particle counter. H2S doping of the CVD-Al2O3 process improves the homogeneity of thickness and growth rate of the Al2O3 layer. The number of particles produced in the reactor whose size was larger than 200 nm was dramatically reduced by H2S doping. The effect of H2S doping appears to be a reduction of the size of Al2O3 particles present in the reactor. These smaller particles have a greater mobility, which will allow them to arrive at the surface, regardless of the shape or arrangement of the substrate inside the reactor.
© EDP Sciences 1999