The influence of collision cascade density on GaN surface topography and surface shift under atomic and molecular ion bombardment

Effect of collision cascade density on GaN surface properties under molecular and atomic ion bombardment have been studied. At low level of cascade density swelling prevails sputtering. In the case of molecular ion irradiation, when cascade is high, sputtering is more effective than swelling. Threshold behavior of these phenomena is established and corresponding values are found. Physical reasons are suggested.