Point Defects in Relaxed Si1-xGex Alloy Layers

Abstract

AbstractThe use of compositionally graded buffer layers in the growth of fully relaxed epitaxial Si1−xGex alloy layers has led to a major improvement in crystalline quality. A considerable reduction in the density of the threading dislocations has become possible, facilitating point defect studies in these materials. The issues addressed in this review are inherent to the coupling between band gap engineering and defect-related levels. Among them, the pinning behaviour, charge state effects and their consequence upon the thermal stability of point defects are discussed together with the impact of the fluctuation in Ge distribution