ABSTRACT
The in situ and ex situ oxidation of ZnTe and CdTe surface has been studied by high-resolution electron microscopy. The in situ oxidation occurred as a result of electron irradiation within the electron microscope and was found to involve an initial amorphization of the surface of the bulk crystal, followed by the formation of small crystallites of the cation oxide. It appeared that the anion species were being desorbed from the surface by a non-thermal electron-stimulated process. The ex situ oxidation simply involved annealing in air, with subsequent observations by electron microscopy. Differences between the materials were seen in the ex situ studies. In the case of ZnTe, a layered sequence of ZnTe/Te/ZnO was observed, with the large Te crystals(up to 1000Å across) invariably in an epitaxial relationship with the bulk material, and the smaller ZnO crystal(~50Å) at the surface in random orientations. The formation of an epitaxial TeO2 layer immediately adjacent to the bulk CdTe crystal was, however, observed in the ex situ CdTe oxidation studies.
