HIGH-GAIN SI-GE HETEROJUNCTION BIPOLAR-TRANSISTORS GROWN BY RAPID THERMAL CHEMICAL VAPOR-DEPOSITION

Rapid thermal chemical vapor deposition (RTCVD) is a processing technique that results from the combination of radiant heating lamps and a CVD chamber. It is the ultimate cold-wall CVD reactor and allows one to clean wafers in situ and immediately thereafter to deposit epitaxial layers. Very thin layers (less than 100 Å) can be deposited by either gas or lamp power switching. We report here the growth of high-quality silicon layers, both intrinsic and in situ doped, and devices that were processed from multilayer structures. Heterojunction bipolar transistors (HJBTs) containing 30% Ge in the base layer have been grown, and current gains as high as 300 have been observed. These HJBTs show great promise as microwave transistors. RTCVD processing is a production-worthy technology that will play an important role in the manufacture of future heterostructural devices. © 1990.