The As-pressure dependence of the incorporation diffusion length was studied on the (001) and (110) surfaces. The incorporation diffusion length on both surfaces was found to be inversely proportional to the square root of the As pressure at low As pressures, but became proportional to the reciprocal of the pressure at high As pressures. It was deduced that the growth reaction with As4 was first-order at low As pressures, but was second-order at high As pressures. The As-pressure dependence of the Ga lateral flux between (001) and (110) was also studied. It was shown that the direction of intersurface diffusion reversed with changes As pressure. At low As pressures, Ga intersurface diffusion occurred from the (110) side-surface to the (001) top-surface, whereas it occurred in the opposite direction at high As pressures.
Arsenic pressure dependence of incorporation diffusion length on (001) and (110) surfaces and inter-surface diffusion in molecular beam epitaxy of GaAs A.Yamashiki, T.Nishinaga: Journal of Crystal Growth, 1999, 198-199[1-4], 1125-9