Peculiarities and mechanism of the cone growth under ion bombardment

Cones were grown on a copper surface under simultaneous irradiation by both Ar+ ion and seed tungsten atom flows. The cones were photographed in the SEM after certain irradiation dose at different stages of their life cycle. The cones originate as protuberances growing normally to the surface. They are believed to grow due to ion induced surface stresses on the places where concentration of the implanted seed atoms exceeded the solution limit and destroyed the crystal structure. During certain period of irradiation the growing cones had stable shape and constant growth rate - ''stable shape stage (SSS)''. The conditions for the existence of SSS are presented. The main causes of the cone growth during SSS are considered to be sputtering and diffusion to the cone top stimulated by ion induced stresses on the cone slopes. Using the suggested approach, specific peculiarities of cone formation are discussed.