Profiling of electron accumulation layers in the near-surface region of InAs (110)

Abstract

High-resolution electron energy-loss spectroscopy (HREELS) has been used to study the surface-plasmon excitations in degenerate n-type InAs (110) surfaces prepared by atomic hydrogen cleaning (AHC), and a range of different argon-ion bombardment and annealing (IBA) procedures. Using semiclassical dielectric theory simulations of the HREEL spectra, and modified Thomas-Fermi approximation charge profile calculations, the dependence of the bulk carrier concentration, accumulation layer profile, plasmon lifetime, carrier mobility, and spatial dispersion on the IBA conditions, was determined. The results from the IBA surfaces were compared with those from damage-free surfaces prepared by AHC. The density of created defects increased both as a function of the bombardment angle when varied from grazing to normal incidence for 500 eV IBA, and when the bombardment energy was increased from 500 to 1500 eV. The band bending and the potential-well widths used to simulate these data, were found to be dependent upon the bombardment energy. However, these parameters changed proportionally, resulting in the surface-state density remaining independent of the surface preparation method.