The Growth and Application of Metastable Germanium Silicon Alloys by Molecular Beam Epitaxy

This paper will review our current understanding of Ge sub x Si sub 1-x strained layer growth and the application of such films to heterojunction devices. Particular attention will be paid to the issues of film and defect nucleation, the origin and kinetics of strain relieving defects, the utility of superlattices in defect confinement and the effect of deliberate atomic monolayer ordering. Defect kinetics will be illustrated using films of real time, in-situ TEM annealing experiments. These films reveal strong variations in defect interaction and morphology as a function of Ge fraction. Device applications will be discussed in the context of their dependence upon the alteration in bandstructure induced by lattice mismatched crystal growth.