Arsenic pressure dependence of incorporation diffusion length on (0 0 1) and (1 1 0) surfaces and inter-surface diffusion in MBE of GaAs

Abstract

The arsenic pressure dependence of the inter-surface diffusion on the GaAs(0 0 1) and (1 1 0) surfaces was studied by using microprobe-RHEED/SEM MBE. Firstly, the arsenic pressure dependence of the incorporation diffusion length was studied on the (0 0 1) and the (1 1 0) surfaces. The incorporation diffusion length on both (0 0 1) and (1 1 0) was found inversely proportional to the square root of the arsenic pressure at low arsenic pressure, while it becomes proportional to inverse of the arsenic pressure at high arsenic pressure. From these results, it was deduced that the growth reaction with As 4 is of the first order at low arsenic pressure, while it becomes of the second order at high arsenic pressure. Next, the arsenic pressure dependence of the Ga lateral flux between (0 0 1) and (1 1 0) was studied. It was shown that the direction of the inter-surface diffusion is reversed with changing the arsenic pressure. At low arsenic pressure, the Ga inter-surface diffusion occurs from the (1 1 0) side surface to the (0 0 1) top surface, while it occurs in the opposite direction at high arsenic pressure.