High-quality n-Si/i-p + -i SiGe/n-Si structure grown by ultra high vacuum chemical molecular epitaxy

The n-Si/i-p + -i SiGe/n-Si structure was grown by ultra high vacuum chemical molecular epitaxy, and analysed by high resolution X-ray diffraction, cross-sectional transmission electron microscopy, and secondary ion mass spectroscopy. A high-quality SiGe base layer with an abrupt interface to the Si was obtained. No defects were observed in the n-Si/i-p + -i SiGe/n-Si structure. Both the Ge and boron atoms are uniformly distributed in the p + -SiGe layer, and the changes of profile of both boron and Ge atoms are abrupt from the n-Si to the SiGe layer. A high-performance microwave power SiGe heterojunction bipolar transistor (HBT) was made from the n-Si/i-p + -i SiGe/n-Si structure. Therefore, device-quality n-Si/i-p + -i SiGe/n-Si structures can be grown by ultra high vacuum chemical molecular epitaxy.