Two-dimensional nuclei of GaAs which were grown on a singular (001) surface by metal-organic chemical vapor deposition were observed by means of high-vacuum scanning tunnelling microscopy. The nuclei extended in the [110] direction, which was opposite to that of molecular beam epitaxial growth. The nucleus number density was obtained from scanning tunnelling microscopic images, and the relationship between the density and the surface diffusion coefficient of Ga species was estimated by simulating growth at the surface. The surface diffusion coefficient was estimated to be equal to about 10-7cm2/s at 530C.

M.Kasu, N.Kobayashi: Journal of Crystal Growth, 1994, 145[1-4], 120-5