The incorporation diffusion length of surface-migrating adatoms on molecular beam epitaxial material was studied theoretically and experimentally. By using microprobe reflection high-energy electron diffraction and scanning electron microscopic techniques, it was demonstrated that the incorporation diffusion length depended strongly upon the As partial pressure, and was of the order of 1. This behavior was explained by assuming that the Ga flux which entered the step exceeded the As flux. When the Ga flux which entered the step was lower than that of As, the incorporation diffusion length decreased to that of the step separation; and was then typically of the order of tens of nm. It was concluded that the balance of Ga and As fluxes which entered the step edge determined the incorporation diffusion length of Ga.

T.Nishinaga, X.Q.Shen: Applied Surface Science, 1994, 82-83, 141-8