1. Layer-by-layer etching of Cl-adsorbed silicon surfaces by low energy Ar+ ion irradiation
- Author
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Kim, Bum-Jun, Chung, Saehoon, and Cho, Sung M.
- Subjects
- *
SEMICONDUCTOR etching , *SILICON , *SURFACE chemistry - Abstract
Layer-by-layer etching of Si(1 0 0) has been investigated by alternating chlorine adsorption and Ar+ ion irradiation. As the Ar+ ion source, a helicon plasma has been used to invoke the surface reaction of Si with the adsorbed chlorine. At a chlorine partial pressure of 10 mPa, the Si surface was found to be fully saturated with adsorbed chlorine in 20 s. In order to achieve the layer-by-layer etching of Si, the Ar+ ion acceleration energy should be above 20 eV at the time of chlorine adsorption. At energies above 40 eV, however, sputtering of Si was found to occur. The self-limited etch rate was measured to be half monolayer per cycle, which was 0.68 A˚ per cycle. The roughness of Si surface was found to increase during the etching by about 22% after 900 cycles. [Copyright &y& Elsevier]
- Published
- 2002
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