Study of the topography of silicon surface evolution under irradiation by a gallium ion beam

Abstract

The silicon surface was irradiated with 30 keV gallium ion beam at incidence angles from 0 to 50° and fluences from 6·1016 to 5·1018 cm−2. Surface topography was investigated by scanning electron microscopy. It was found that one of four types of a relief can be formed on the silicon surface depending on the ion beam incidence angle and these fluences. Pattern formation starts with fluences of ∼2·1017 cm−2. The peculiarities of a relief evolution can be explained by the angular dependences of silicon sputtering with gallium ion beam and the possible existence of implanted gallium in the near-surface layer in the form of precipitates.