VAPOR-PHASE EPITAXY OF CDTE ON SAPPHIRE AND GAAS

CdTe films were deposited on three kinds of sapphire substrate and two kinds of GaAs substrate by open tube vapor transport. X-ray Laue diffraction study showed that CdTe(111) film grew on every kind of sapphire substrate used, i.e. on the (0001) basal plane, the (1120BAR)A plane and the (1102BAR)R plane, and that there exist a few degrees of tilt angle between CdTe(111) and the lattice plane of each substrate. The process of making the tilt angle may be explained by the atomistic mismatch model of the Cd and Al arrangement which is projected on the film-substrate interface. On GaAs(100), either CdTe(111) or CdTe(100) was obtained, whereas only a twin crystalline film was obtained on GaAs(111). These results are also consistent with the mismatch model of Cd and Ga atoms.