Measurements of diffusion coefficient of CF radical in DC pulsed CF{sub 4} discharge plasma
- Kanagawa Institute of Technology, Atsugi (Japan); and others
Low-pressure CF{sub 4} discharge plasmas are used extensively for dry etching of semiconductor devices. Mixing CF{sub 4} with O{sub 2} or H{sub 2} provides etching selectivity between Si and SiO{sub 2}. Laser induced fluorescence (LIF) has been used as a diagnostic technique in such plasmas, due to the high sensitivity and selectivity of its measurement. This LIF technique has been applied to obtain the information on the buildup and decay of CF{sub 2} and CF densities in pulsed CF{sub 4} discharges. The diffusion coefficient of the radical is one of the important parameters needed to clarify the etching mechanism in CF{sub 4} plasma. Measurements of the diffusion coefficient have been made for CF{sub 2} radical in CF{sub 4} and O{sub 2}. In this study, we have used LIF to probe the decay of transient CF radical density in pulsed CF{sub 4} plasma and have determined the diffusion coefficient of the CF radical in CF{sub 4}.
- OSTI ID:
- 212794
- Report Number(s):
- CONF-950749--
- Country of Publication:
- United States
- Language:
- English
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