Acceptorlike behavior of defects in SiGe alloys grown by molecular beam epitaxy

The Ge composition dependence of the densities and energy levels of the acceptorlike defect states that are generated during the solid-source molecular beam epitaxy (SSMBE) of SiGe films was investigated. Hall measurements in a wide temperature range were carried out, and a previously unreported very shallow acceptorlike state was found. We provide evidence that the observed acceptorlike states are relevant to intrinsic point defects.