The As pressure dependence of Ga adatom surface diffusion during molecular beam epitaxy onto non-planar substrates was investigated. By using in situ scanning microprobe reflection high-energy electron diffraction techniques, the distribution of the growth rate of GaAs on the (001) surface near to the edge of the (111)A or (111)B sidewall was measured under various As pressures. It was found that the surface diffusion length of Ga adatom incorporation on the (001) surface, as deduced from the growth rate distribution, was of the order of  and exhibited a marked dependence upon the As pressure. A simple model which was based upon 1-dimensional surface diffusion was used to estimate the lifetime for Ga adatom incorporation on other surfaces.

X.Q.Shen, D.Kishimoto, T.Nishinaga: Japanese Journal of Applied Physics 1, 1994, 33[1A], 11-7