An X-ray diffraction study of oxide removal from InSb(001) substrates

A study of the removal of the native oxide from InSb(001) substrates using X-ray diffraction and Auger electron spectroscopy is reported. Several methods have been investigated to produce atomically flat, oxide free, surfaces. These include thermal annealing, argon ion bombardment at both room temperature and elevated temperature, and irradiation of the surface with atomic hydrogen. The quality of the resulting c(8 × 2) surface gave a good indication of the relative success of each technique. The reflected X-ray intensity was measured as a function of perpendicular momentum transfer l along the specular (00l) rod and gives a clear indication of the roughness of each surface. The lateral order was determined from the width of the in-plane fractional order reflections. The results show a marked improvement in surface order when using hydrogen irradiation/annealing as opposed to thermal annealing alone. A more significant improvement in surface quality, however, was noted when sputtering at elevated temperature.