The characteristics of silicon etching using radio-frequency (rf) substrate biased ultrahigh-frequency (UHF) plasma determined by using a Cl2 etchant were investigated. The silicon etching rate and the etching profile were improved by decreasing the substrate bias frequency to less than 600 kHz. It is suggested that a large number of negative chlorine ions is generated in the high-density, low-pressure UHF plasma because of the extremely low electron temperature. The low-frequency substrate bias accelerates the negative and positive ions alternately to the substrate surface. As a result, the low-frequency biased UHF plasma can be used to achieve high-rate, highly anisotropic, and microloading-free silicon etching with a 600 kHz rf substrate bias.
|Number of pages||6|
|Journal||Journal of Vacuum Science and Technology A: Vacuum, Surfaces and Films|
|Publication status||Published - 1996 Jan 1|
ASJC Scopus subject areas
- Condensed Matter Physics
- Surfaces and Interfaces
- Surfaces, Coatings and Films