Effects of electron temperature in high-density Cl{sub 2} plasma for precise etching processes
- Microelectronics Research Laboratories, NEC Corporation, 34 Miyukigaoka Tsukuba, Ibaraki 305 (Japan)
- ANELVA Corporation, 5-8-1 Yotsuya Fuchu, Tokyo 183 (Japan)
Silicon etching characteristics are investigated by using radio-frequency (rf) biased ultrahigh frequency (UHF) and other conventional plasmas (electron cycotron resonance plasma, inductive coupled plasma, surface wave plasma) determined by using a Cl{sub 2} etchant. The silicon etching rate and its pattern dependence are significantly improved by decreasing the electron temperature when supplying a 600-kHz rf bias. In particular, use of the UHF plasma allows high-rate and microloading-free silicon trench etching. It is suggested that a larger number of negative ions are generated in the UHF plasma because of the extremely low electron temperature. The low-frequency bias accelerates the negative and positive ions alternately to the substrate surface. As a result, the low-frequency biased UHF plasma reduces the charge accumulation on the substrate. {copyright} {ital 1996 American Institute of Physics.}
- OSTI ID:
- 286525
- Journal Information:
- Applied Physics Letters, Vol. 69, Issue 8; Other Information: PBD: Aug 1996
- Country of Publication:
- United States
- Language:
- English
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