In situ oxidation processes for In III-V compound semiconductors studied by high-resolution electron microscopy

Abstract

Oxidation of the amorphous and crystalline material at, and near, the surfaces of InP, InAs and InSb crystals takes place in situ during observation with a 400 kV atomic-resolution electron microscope. The phases present in the surface layers can be identified by comparison of lattice spacings with those of the bulk material, using the optical Mractogram technique. In general, the most prevalent material formed is found to be In₂O₃ and, for InAs, there is often an epitaxial relationship between the oxide and the substrate. However, in some regions of the original amorphous layer, small crystah (< 50 Å) of the corresponding In compound semiconductors are recrystallized, and small amounts of metallic As are observed for Ids, and metailic In for InP. It is concluded that electron-beam-stimulated desorption of the anion species takes place, followed by oxidation of the residual In metal.