The evolution of pyramidal structures on surfaces bombarded at oblique angles

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.