SINGLE-WAFER EPITAXY OF SI AND SIGE USING UHV-CVD

In this paper we describe Si and SiGe alloy growth on a Si substrate u sing a UHV-CVD reactor and compare our studies to equivalent systems w orking at low pressure (10(-4) torr range). The UHV-CVD results are th en compared to those obtained RTCVD systems operating in the torr rang e: the same physical phenomena such as the adsorption mechanism is val id for Si epitaxy and the same behaviour in selective epitaxy and high p-type doping levels is obtained. For low temperature growth, an adva ntage of UHV is demonstrated by the low gas flow which allows low grow th rates. Finally, we present a new 200 mm wafer compatible UHV-RTCVD reactor. This single wafer reactor integrates the most important advan tage of RTCVD, the external lamp heating system, and a new optimized g as injector while maintaining ultravacuum conditions during processing .