Abstract
A high-precision RT-CVD epitaxial growth technique has been successfully developed for fabricating ultra-low-power SiGe HBTs. Extremely high-concentration doping with abrupt profiles in the Si/SiGe layers was achieved without high-temperature activation annealing. Furthermore, good crystallinity of the grown layer was also achieved, which results in low resistivity. A major advantage of the technique is that SiGe HBTs fabricated using it have high cutoff frequencies at low current density (50 GHz at JC = 0.2 mA/μm2), which makes them highly suitable devices for use in future low-power high-speed communication systems.