Growth of CdTe films on sapphire by molecular beam epitaxy

Results of initial attempts to grow cubic-phase CdTe films on sapphire by molecular beam epitaxy are reported. Depositions have been completed on (11̄02) R-plane, (12̄10) A-plane, and (0001) basal plane substrates. Substrate temperatures in the range 260–350 °C were employed along with deposition rates of 1.5–7.5 Å/s. Depositions on (11̄02) sapphire generally produced films containing some elements of the hexagonal phase, as disclosed by x-ray diffraction and UV reflectance measurements. Sharp cubic-phase epitaxy was obtained for thick (∼5 μm) CdTe films grown on (12̄10) and (0001) sapphire substrates. The epitaxial films are smooth and mirrorlike in appearance. Nomarski micrographs show a featureless CdTe surface.