AVS 46th International Symposium
    Thin Films Division Monday Sessions
       Session TF-MoP

Paper TF-MoP12
Effect of C@sub 2@ Radicals on Diamond Growth Using Low-Pressure, Radio Frequency, CH@sub 3@OH/H@sub 2@/H@sub 2@O Inductively Coupled Plasma

Monday, October 25, 1999, 5:30 pm, Room 4C

Session: Poster Session
Presenter: T. Shiomi, Meijo University, Japan
Authors: T. Shiomi, Meijo University, Japan
H. Nagai, Meijo University, Japan
M. Hiramatsu, Meijo University, Japan
M. Nawata, Meijo University, Japan
Correspondent: Click to Email
Previously we demonstrated the successful formation of diamond crystals using a low-pressure, radio frequency (rf, 13.56 MHz), inductively coupled plasma (ICP) in the total pressure range of 9.3-18.6 Pa.@footnote 1@ In contrast with conventional methods of diamond chemical vapor deposition (CVD) employing high-pressure plasma (@>=@100 Pa), in the case of low-pressure, high-density, and highly dissociated plasmas, carbon dimer (C@sub 2@) radicals or carbon atoms instead of methyl radicals might be major species for film formation. C@sub 2@ radical is considered to be one of important radicals for the nanocrystalline diamond deposition using plasma-enhanced CVD.@footnote 2@ In this work, C@sub 2@ radical density in a low-pressure (@<=@13 Pa), rf-ICP employing CH@sub 3@OH/H@sub 2@/H@sub 2@O source for diamond CVD was measured using absorption spectroscopy with Xe lamp emitting a continuous spectrum as a light source. The correlation between the absolute C@sub 2@ radical density and the quality of diamond films was investigated. In the Raman spectra of diamond formed using a low-pressure rf-ICP, a broad peak around 1140 cm@super -1@ arising from nanocrystalline diamond was observed together with the strong 1332 cm@super -1@ diamond Raman peak. C@sub 2@ radical density increased almost linearly with increasing rf input power or CH@sub 3@OH partial pressure. On the other hand, C@sub 2@ radical density decreased with increasing H@sub 2@O partial pressure, while the intensity of 1332 cm@super -1@ diamond Raman peak increased with increase of the H@sub 2@O partial pressure up to 5.3 Pa. @FootnoteText@@footnote 1@H. Noda, H. Nagai, M. Shimakura, M. Hiramatsu, and M. Nawata, J. Vac. Sci. Technol. A 16, 3170 (1998). @footnote 2@D. M. Gruen, S. Liu, A. K. Krauss, and X. Oan, J. Appl. Phys. 75, 1758 (1994).