Preferential sputtering

Abstract

An overview of recent studies on preferential sputtering is presented. Particular attention is given to a historical survey of preferential sputtering studies, particularly on Cu−Ni and Au−Cu alloys, which have the longest history of investigation, as the most typical model-case where radiation induced surface segregation (RIS), atomic mixing in collision cascade, and radiation enhanced diffusion (RED) take place. Special experimental arrangements developed for those investigations have often shed light on new aspects of preferential sputtering. Computer simulation mainly based on the Monte Carlo approach has now succeeded in describing the preferential sputtering processes in nonmentals with considerable success, whilst the simulation can be extended to alloys only for the limited cases where experimental data and/or precise knowledge on RIS are available. As an experimental approach, it is emphasized that a surface analytical technique (AES, XPS, etc.) combined with ISS has become the most powerful tool to provide an intimate insight into preferential sputtering. For this purpose a simple but useful experimental arrangement, which enables ISS-AES sequential measurement with a commercial Auger microprobe to be performed, is proposed with a practical application to the preferential sputtering study of Au−Cu alloys.