ATOMIC HYDROGEN-ASSISTED GAAS MOLECULAR-BEAM EPITAXY

A continual irradiation of atomic H during the growth of GaAs in molecular beam epitaxy (MBE) has been shown to be a viable method to obtain sharp heterointerfaces and high-quality epitaxial layers. We provide some fundamentally important observations related to atomic scale mechanisms and interactions, and the growth models for atomic H-assisted homoepitaxial GaAs MBE are proposed. Atomic H has been shown to be an efficient surfactant reducing the surface and total energy of GaAs(100) that acts to promote layer-by-layer and step-how growth mode. However, the actual growth kinetics is different depending on the growth temperature, which affects the energetic stability of atomic H adsorption on GaAs(100). Furthermore, the continual removal of surface contaminants and also the excess arsenic during the growth are thought to be another important attribute played by atomic H.