Characterization of SiGe/Si heterostructures formed by Ge+ and C+ implantation

Abstract
Formation of SiGe/Si heterostructures by germanium ion implantation was investigated. A germanium‐implanted layer was grown epitaxially in the solid phase by thermal annealing. Two kinds of crystalline defects were observed. One is a misfit dislocation, and the other is a residual dislocation caused by ion bombardment. The pn junction formed in the SiGe layer has a leakage current three orders of magnitude larger than that of a pure Si pn junction fabricated with an identical process except for the Ge+ implantation. Carbon doping in the SiGe layer improves its crystalline quality and the junction characteristics.