APCVD-grown self-aligned SiGe-base HBTs

SiGe-base bipolar technology has emerged during the past few years and is now proceeding to qualify for advanced development and manufacturing. The authors review important aspects of device design, SiGe epitaxy, and transistor integration. A novel high-performance SiGe-base technology is presented as one way to address the upcoming challenges. The characteristic technology features ar the SiGe-base grown by atmospheric-pressure chemical vapor deposition (APCVD), the device doping profile with high base doping and low-doped emitter, and the self-aligned low-parasitic device structure which requires only a very low process thermal budget. The characteristics and performance of the experimental devices are discussed, and discussions are extended to manufacturability aspects of heterojunction bipolar transistors (HBTs) based on SiGe APCVD.