The temperature and pressure dependences of GaAs and AlAs growth rates and migration lengths across a SiO2 mask during metal-organic chemical vapor deposition were investigated. The GaAs growth rate across a SiO2 patterned area was markedly affected by the surface migration of growth species, whereas that of AlAs was not. It was found that the migration length of GaAs species was reduced to 20% of these values when grown at a pressure of 100kPa. The AlAs migration length was 2 orders of magnitude shorter than that of GaAs, and did not depend upon the growth pressure. The large difference in the surface migration behaviors of GaAs and AlAs was explained in terms of the free energy changes that occurred during the chemical reaction between growth species and the SiO2 mask.

K.Hiruma, T.Haga, M.Miyazaki: Journal of Crystal Growth, 1990, 102[4], 717-24