The evolution of pyramidal structures on surfaces bombarded at oblique angles

Abstract

Results are presented relating to the formation of pyramids on obliquely bombarded surfaces. The object was to establish to what extent the underlying laws were similar to those governing surfaces bombarded at normal incidence, i.e. the so-called first-order erosion laws. It was concluded that first-order theory was only in part adequate to explain what was observed, as there was tentative evidence for a role involving redeposition and rather strong evidence for important contributions from net growth, asymmetrical flux enhancement, beam divergence, and latent planes.

Cone formation on Ag surface bombarded by Ar at oblique incidence

“…The underlying mechanism for oblique cone or pyramid formation is found to be similar to that responsible for the formation of normal cones or pyramids. However, Auciello and Kelly (1982) identified five sources of perturbation to the first-order erosion theory to account for the evolution of oblique cones. These are the growth of topography relative to the instantaneous surface, asymmetrical flux enhancement originating from the high-angle surface, redeposition of sputtered material, effects due to beam divergence, and the role of latent planes.…”