Surface Morphology Evolution of GaAs by Low Energy Ion Sputtering

Abstract

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 Kuramoto-Sivashinsky 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.

Nanorippling of ion irradiated GaAs (001) surface near the sputter‐threshold energy

“…Under these conditions, the GaAs surface is amorphized and smoothing by mass redistribution dominates . This is also supported by the experimental results of Wang et al , who observed no pattern formation on Ar + bombarded GaAs surface at room temperature below the energy of 600 eV. When the temperature of the substrate is raised above the recrystallization temperature of GaAs, e.g., at 450 °C, the ripple pattern is found to develop on the surface.…”

Role of surface composition in morphological evolution of GaAs nano-dots with low-energy ion irradiation

“…There are a lot of discrepancies between theories and experiments about the parameters that control the size as well as the density of dots. Wang et al [ 23 ] observed the formation of nano-dots with an average diameter of 22 nm on GaAs surface by Ar + ion sputtering at about 1.2 keV at normal incidence. Datta et al [ 24 ] reported that the average size of nano-dots is of the order of 200 nm on GaAs (100) by 60-keV Ar + ion irradiation at 60° of ion incidence with respect to surface normal.…”

Temperature and excitation density dependent photoluminescence of sputtering-induced GaAs/AlGaAs quantum dots

“…The sputtering chamber pressure is maintained below 4 × 10 −4 Torr by a turbo pump. The sample is sputtered, based on optimization of the previously reported experiments [14], for 300 s with 1000 eV ion energy and 9 mA beam current, which is equivalent to 7.9 × 10 15 cm −2 s −1 beam flux.…”