Unveiling the Magic of H2S on the CVD-AI2O3 Coating

Takatoshi Oshika, Akio Njshiyama, Yoshifumi Ito, Kouichi Nakaso, Manabu Shimada

Research output: Contribution to journalArticlepeer-review


Achieving a uniform film thickness profile over a substrate has been difficult in CVD-AI2O3 coating processes. Although this problem can be solved by H2S-doping to the source gas mixture, AICI3/CO2/H2, the role of H2S in the mechanisms of the CVD coating have not been clarified. In this study, the effects of H2S-doping on the improvement of the uniformity of a coated layer is studied, focusing on the particles generated in the gas phase. It is found in the measurement of gasborne particles that the number concentration of particles larger than 200 nm in diameter is reduced dramatically by the H2S-doping. The concentration is over 108 particles/m3 when no H2S is doped, while it is less than 106 particles/m3 at 0.20% doping. The improvement of the coating by H2S-doping is concluded to be caused by a size reduction of particulate matters of the A12O3 precursors that leads to an increase of the diffusivity.

Original languageEnglish
Pages (from-to)749-753
Number of pages5
JournalKagaku Kogaku Ronbunshu
Issue number6
Publication statusPublished - 2000
Externally publishedYes


  • aluminum oxide
  • chemical vapor deposition
  • measurement of particles generated in gas phase
  • particle diffusivity
  • surface coating

ASJC Scopus subject areas

  • Chemistry(all)
  • Chemical Engineering(all)


Dive into the research topics of 'Unveiling the Magic of H2S on the CVD-AI2O3 Coating'. Together they form a unique fingerprint.

Cite this