ELECTRONIC EFFECTS OF SURFACE IN ATOMS AT CLEAN AND HYDROGENATED INP(100)4X2 SURFACES

The InP(100) surfaces being cleaned by ion bombardment and annealing (IBA) are known to be In-rich. Exposure to atomic hydrogen gives rise to an even higher In surface content. The nature of these In atoms at the clean and the hydrogenated surface was characterized by the techniques of ultraviolet and X-ray photoelectron spectroscopy (UPS, XPS) as well as low-energy electron diffraction (LEED), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDX). The heavily hydrogenated surface is dominated by metallic droplets of In- Line shape analysis can separate the contributions from these droplets and the non-metallic area in between, giving new insight in band bending at this surface. The clean surface also exhibits features which might point to a metallic character of the In surface atoms, but it is argued that these features have their origin in In atoms bound in dimers at the surface.