GAAS HETEROEPITAXIAL GROWTH ON VICINAL SI(110) SUBSTRATES BY MOLECULAR-BEAM EPITAXY

We report the growth mechanism of GaAs on vicinal Si(110) substrates b y molecular beam epitaxy, and investigate the effects of off-angle and -direction on the crystalline quality of grown films. The quality was improved with the increase of the off-angle and strongly influenced b y the off-direction. Off-direction toward the [001] was better than th at toward the [110] for obtaining high-quality films. The cause is rel ated to the structure and density of the steps. We infer from reflecti on high-energy electron diffraction results that GaAs films on vicinal Si(110) with off-angles above 2 degrees toward the [001] direction gr ew up to a thickness of 3 Mn in step-flow-like mode. The spotty reflec tion high-energy electron diffraction patterns characteristic of three -dimensional growth in GaAs/Si(100) were not observed at a thickness a bove 3 nm. (C) 1994 American Institute of Physics.