Ken-ichi Itoh, Shinya Ohmachi, Hideo Aida, and Osamu Matsumoto*

Department of Chemistry, Aoyama Gakuin University
Chitosedai, Setagaya-ku, Tokyo 157-8572, Japan
matumoto@candy.chem.aoyama.ac.jp

In the diamond deposition, the adsorption of activated species prepared in the plasma on the surface of the substrate placed in the reactor and the desorption of certain species from the surface contribute the promotion of the reaction. We have investigated the diamond deposition using several plasma generation methods and carbon sources and have verified the reaction scheme, especially a role of adsorbed species on the deposit, in the diamond deposition with chlorinated benzene [1, 2] in the plasma jet and with the mixture of carbon dioxide and methane [3] in the microwave discharge as carbon source.

In the present paper brominated benzenes, C6H5Br and C6H4Br2, were selected as carbon sources for the deposition and were added into the Ar-H2 plasma jet. The role of the adsorbed species on the deposit on the substrate placed in the plasma jet on the diamond deposition was investigated with the characterization of the deposits and identification of the species in the plasma and adsorbed on the surface of the deposit. As the comparison of the results obtained with the results in the diamond deposition using benzene as carbon source, the interaction of species in the plasma jet with the adsorbed bromine on the surface of the deposit would promote the diamond deposition reaction like the diamond deposition with chlorinated benzene as carbon source [2].

References

[1] T. Kotaki, N. Horii, H. Isono, and O. Matsumoto, J. Electrochem. Soc., 143 (1996) 2003.
[2] N. Horii, N. Suzuki, K. Itoh, T. Kotaki, and O. Matsumoto, Diamond Relat. Mater., 6 (1997) 1874.
[3] K. Itoh and O. Matsumoto, Thin Solid Films, accepted for publication (1998).