Oxide formation on the CdTe(111) A (1 X 1) surface

A CdTe(111)A (1 X 1) surface, prepared in situ by argon ion bombardment and annealing (at 250 degrees C), was oxidized at the pressure of 1 x 10(-5)-5 X 10(-5) Torr of molecular oxygen excited by the hot filament of the ion gauge. The surface atomic structure was studied by low-energy electron diffraction (LEED). The surface chemical composition and the oxidation process were monitored by recording the energy position and shape of Te 3d, Cd 3d, O Is and C 1s core level peaks by X-ray photoemission spectroscopy. The excess of Te on the clean CdTe(111)A (1 x 1) surface was detected. Then, the increase of oxygen bound on the surface was observed as a function of the gas exposure. Symptoms of selective oxidation of Te atoms on the surface and in subsurface region were revealed. (C) 2000 Elsevier Science B.V. All rights reserved.