Surface Morphology Evolution of GaAs by Low Energy Ion Sputtering

Low energy Ar ion sputtering, typically below 1,200 eV, of GaAs at normal beam incident angle is investigated. Surface morphology development with respect to varying energy is analyzed and discussed. Dot-like patterns in the nanometer scale are obtained above 600 eV. As the energy approaches upper eV range regular dots have evolved. The energy dependent dot evolution is evaluated based on solutions of the isotropic KuramotoSivashinsky equation. The results are in agreement with the theoretical model which describes a power law dependency of the characteristic wavelength on ion energy in the ion-induced diffusion regime.