Epitaxial growth of stoichiometric (100) GaAs at 75 °C

Stoichiometric single crystal GaAs is grown at 75 °C by a migration-enhanced-epitaxy (MEE) technique. The stoichiometry of the GaAs films can be controlled by adjusting the arsenic monolayer deposition time. For Ga-rich compositions, epitaxy breaks down and polycrystalline GaAs results. For stoichiometric GaAs, and As-rich compositions, epitaxy proceeds and specular stoichiometric films can be grown to significant thicknesses. Reflection high-energy electron diffraction patterns indicated some surface roughness that increased for compositions closer to those which were Ga rich. This work suggests that low-temperature growth by MEE results in limited-thickness-epitaxy (LTE) behavior for GaAs that is very different from low-temperature growth by conventional molecular beam epitaxy. The results of this work indicate the importance of stoichiometry, surface roughening, and surface diffusion phenomena in determining regimes where epitaxy occurs at low temperature. A maximum LTE epitaxial thickness of 300 nm wa...