ABSTRACT
The development of spontaneous stationary equilibrium patterns on metallic or semi-conductor solid surfaces during ion-sputtered erosion at normal incidence is investigated by means of both hexagonal and rhombic planform nonlinear stability analyses applied to the appropriate governing equation for this phenomenon. In particular, that process can be represented by a damped Kuramoto-Sivashinsky nonlinear partial differential spatial-temporal evolution equation for the interfacial deviation from a planar surface, which includes a deterministic ion-bombardment arrival term and is defined on an unbounded two-dimensional domain in space. The etching of coherent ripples, rhombic arrays of rectangular mounds or pits, and hexagonal lattices of nanoscale quantum dots or holes during this erosion process is based upon the interplay between roughening caused by ion sputtering and smoothing due to surface diffusion. Then, the theoretical predictions from these analyses are compared with both relevant experimental evidence and numerical simulations from some ion-sputtering erosion studies.
