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Author(s):
T. Kenmotsu, T. Kawamura, T. Ono and Y. Yamamura
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Title:
Dynamical Simulation for Sputtering of B_4 C
Date of publication:
Mar. l998
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Key words:
Sputtering, Ion lrradiation, Surface Effects, Metals, Alloys and Compounds, Diffusion
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Abstract:
Using ACAT-DIFFUSE code, we have simulated the fluence dependence of B_4 C sputtering and the associated surface composition change under D^+ ion bombardment. The ACAT-DIFFUSE is a simulation code, which is based on a Monte Carlo method with a binary collision approximation and solves diffusion equations. In the case of near-threshold sputtering, the preferential sputtering of B atoms is enhanced by the threshold effect. As a result, the total sputtering yield at the steady-state is reduced by about 20% compared with low-fluence sputtering. The surface concentration at steady-state is determined by the competitive processes between diffusion and surface-atom removal due to sputtering. At normal incidence the interstitial diffusion contributes appreciably to the steady-state surface concentration, but at grazing incidence this effect is small. Therefore, the steady-state surface concentration ratio at grazing incidence is less than that of normal incidence.
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