GaAs, GaP, and GaAsxP1−x Epitaxial Films Grown by Molecular Beam Deposition

Abstract

Epitaxial films of GaAs, GaP, and GaAsxP1−x were grown on GaAs and GaP in ultrahigh vacuum from molecular beams of Ga, As2, and P2. Reflection electron diffraction patterns indicated the films were epitaxial on GaAs as low as 700 K and on GaP at 870–900 K. At lower temperatures, twinning became excessive. In films of GaAsxP1−x, the ratio As/P was four times the ratio of As2flux/P2 flux incident on the substrate. If the rate-controlling step were solely the reaction of adsorbed Ga with the impinging As2 or P2, the ratios should have been equal; the discrepancy apparently was due to rapid desorption of P from the surface.