Understanding of crystal growth mechanisms through experimental studies of semiconductor epitaxy

Vapor growth mechanism is discussed next taking molecular beam epitaxy of III-V compound as a model system. Here, the mechanism of inter-surface diffusion is investigated. The surface diffusion of group-III elements between facets was studied by changing group-V pressure. It was found that the direction of the inter-surface diffusion is reversed twice as the group-V pressure is increased. This has been attributed to the different group-V pressure dependence of group-III ad-atom lifetime on different facet. It was concluded that in MBE the growth on the facet is conducted by birth and spread of two-dimensional nuclei and by mass transports from next facet and from effusion cell.