High Quality Content by WIKIPEDIA articles! SiGe, or silicon-germanium, is a general term for the alloy Si1-xGex which consists of any molar ratio of silicon and germanium. It is commonly used as a semiconductor material in integrated circuits (ICs) for heterojunction bipolar transistors or as a strain-inducing layer for CMOS transistors. This relatively new technology offers opportunities in mixed-signal circuit and analog circuit IC design and manufacture.