The migration of an As adatom on a Ga-terminated (001) surface was investigated by performing first-principles calculations using density functional theory and a slab model for the surface. The resultant values for the barrier energy were compared with those for hopping in the kinetic Monte Carlo simulation. An anisotropic migration of the As adatom was deduced which agreed with the results of kinetic Monte Carlo simulations as well as with scanning tunnelling microscopic observations. It was shown that an As adatom was more mobile than a Ga adatom, and that the kinetics of both As and Ga atoms on the growing surface were important during molecular beam epitaxial growth.

First-Principles Calculation of Migration Processes of As during Growth on GaAs(001). K.Sekine, N.Ishii, T.Kawamura: Japanese Journal of Applied Physics - 1, 2000, 39[7B], 4285-8