Reflection high-energy electron diffraction study of (111) and (001) CdTe grown on (001) GaAs by pulsed laser evaporation and epitaxy

Abstract

Reflection high-energy electron diffraction investigations of CdTe films grown on (001) GaAs have been carried out. The films were deposited with a pulsed laser evaporation and epitaxy system which was specially developed in order to grow thin films of AII–BVI compounds. Preparation of (001) GaAs substrates included degreasing in standard solvents, etching in a solution of H2S04–H2O2–H2O, vacuum bakeout, and ion etching. The ion etching was found to be relatively effective in obtaining a partially reconstructed surface of GaAs. The growth of (111) CdTe with [Formula: see text] GaAs took place on such a surface. Deposition on ion cleaned (001) GaAs substrates which did not show surface reconstruction resulted in the growth of (001) CdTe with [Formula: see text] GaAs. For samples thicker than ~1 μm, a (001) CdTe-(2 × 1) structure was observed.