| Issue |
J. Phys. IV France
Volume 12, Number 4, June 2002
|
|
|---|---|---|
| Page(s) | 113 - 120 | |
| DOI | https://doi.org/10.1051/jp4:20020085 | |
J. Phys. IV France 12 (2002) Pr4-113
DOI: 10.1051/jp4:20020085
Unveiling the magic of H 2S on the CVD-Al 2O 3 coating. Effect of H 2S on the water gas concentration
T. Oshika, M. Sato and A. NishiyamaMitsubishi Materials Corporation, Central Research Institute, Naka Research Center, 1002-14 Mukohyama, Naka-machi, Naka-gun, lbaraki-ken 311-0102, Japan
Abstract
The aim of this work is to investigate the role of H
2S-doping in the CVD-Al
2O
3 coating process. It is well known that H
2S-doping into the CVD-Al
2O
3 coating process improves thickness uniformity around the substrate, and enhances the deposition rate of an Al
20
3 layer. The source gas mixture of general CVD-Al
2O
3 Coating comprises AICl
3, C0
2 and H
2, wherein Al
20
3 is produced by the hydrisis reaction of AlCl
3 and H
2O that is produced through the "water gas shift reaction,
H2 + C02 -+ H2O + CO". The concentration of CO in the CVD reactor was investigated using gas tester for the gas mixture of H
2 and C0
2 that produces CO along with the same amount of water. It was suggested that H
2S-doping enhanced the formation of H
2O only when surrounding surface was comprised from CVD-coated Al
20
3, meanwhile H
2O formation was significantly restrained by that doping when surrounding surface was other materials such as SiO
2, stainless steel and sintered Al
20
3.
© EDP Sciences 2002