Effect of Atomic Hydrogen on Molecular-Beam Epitaxy of MnAs/GaAs Heterostructures

Abstract

Abstract-MnAs epilayers were grown on GaAs (001) substrates by molecular-beam epitaxy with the supply of atomic hydrogen (He). X-ray diffraction and reflection high-energy electron diffraction characterizations revealed that the growth directions were along the (1100] direction for the epilayer grown with He, and along both the (1100] and (1101] directions for the epilayers grown with/without hydrogen molecules (Bz). Atomic force microscope observations showed that the faceted mounds elongated along the GaAs [110] direction were only observed for the epilayer grown with He, although large three-dimentional islands were observed on the elongations along the GaAs [110] direction for the epilayers grown with/without the supply of Bz. The results indicate that the irradiation of He enhances the growth of MnAs epilayers along the single direction and improves the surface smoothness.