A study of theoretical depth resolution of GaAs/AlAs reference material with low energy inert-gas ions by Monte Carlo simulation

摘要

A Monte Carlo (MC) simulation program written in C++ has been newly developed to describe the dynamic processes of depth profiling with low energy ions. This MC simulation was applied to the depth profiling of GaAs/AlAs reference material for Ne+, Ar+, and Xe+ ions to elucidate the depth resolution attained by surface analytical techniques. The result clearly predicts that there is a considerable difference between the depth resolutions estimated from the leading and trailing edges of Ne+ and Xe+ ions, whereas the difference is quite small for Ar+ ions. Systematic investigation of the dependence of theoretical depth resolution on primary ion energy has revealed that the preferential sputtering primarily caused by the difference in energy transfer to target atoms through elastic collisions between incident ions and target atoms results in the difference between the leading and trailing edges. The inclusion of other factors, e.g. preferential sputtering effect caused by the metallization of Al atoms on the topmost surface, etc. for further improvement of the MC simulation modeling before accommodating quantitative arguments on the depth resolution is strongly recommended. Copyright (C) 2006 John Wiley & Sons, Ltd.