The molecular-beam epitaxial growth of Si on Ga-activated (111) Si surfaces was studied by using microprobe high-energy electron diffraction methods. The substrate temperature-dependence of the denuded zone-width of 2-dimensional nuclei was measured for various growth rates, and this yielded the activation energy for surface diffusion. The latter energy was estimated to be equal to about 0.5eV for a Ga-adsorbed surface, and equal to about 2eV for a clean surface.

H.Nakahara, M.Ichikawa: Applied Physics Letters, 1992, 61[13], 1531-3