Chapter IV - Epitaxial structures

Abstract

This chapter reviews possible effects of crystallographic texture, grain morphology, and grain size modes of growth on the structure of epilayers. The production of pseudomorphic epilayers and useful device structures is facilitated by the absence of mobile dislocations in the epilayer substrate system..Heteroepitaxy is also found to occur when the misfit between unit cells of epilayer and substrate, having the same symmetry, is large or when these unit cells have different symmetry. The crystallographic relations between film and substrate in these studies are independent of any bonding that exists across the film–substrate interface, but are entirely dependent on features, such as cleavage steps, that exist on the surface of the substrate. It is believed that there is a critical temperature above which epitaxial deposition occurs via the migration of terrace steps without the nucleation of adatom clusters on the terraces.