Self-aligned selective-epitaxial-growth Si/sub 1-x-y/Ge/sub x/C/sub y/ HBT technology featuring 170-GHz f/sub max/

Si/sub 1-x-y/Ge/sub x/C/sub y/ selective epitaxial growth (SEG) was performed by cold-wall ultra-high-vacuum chemical vapor deposition (UHV/CVD), and a Si/sub 1-x-y/Ge/sub x/C/sub y/ layer with good crystallinity was produced by optimizing the growth conditions. As a result of applying Si/sub 1-x-y/Ge/sub x/C/sub y/ SEG to form the base of a self-aligned heterojunction bipolar transistor (HBT), device performance was significantly improved by suppression of B outdiffusion; namely, a maximum oscillation frequency of 174 GHz was obtained.