Atom diffusion during MBE growth on patterned substrate

Abstract

MBE growth on patterned substrate has been studied by means of transmission electron microscopy (TEM). The surface morphology development during the initial stage of epitaxial growth and the lateral epilayer thickness variation have been studied on a nanometer scale. A diffusion model has been proposed to explain the observed phenomena. Based on this diffusion model, it is proved that the diffusion length of adatoms on (100) plane can be measured from the cross-sectional shadow image as well as the cross-sectional TEM images of the grown layers. Again, from the diffusion model, it is found that Ga adatoms diffusion length ratio on (115A) over that on (100) can be measured from the GaAs layer thickness variation on (100) and at the intersection between (100) and (115A). The ratio of Ga adatoms diffusion length on (115A) over that on (100) is reported for the first time. © 1998 Elsevier Science B.V. All rights reserved.