Properties of high-performance phototransistor photodetector (PTPD) in standard SiGe BiCMOS technology

A high-performance phototransistor photodetector (PTPD) in commercial 0.35 mum SiGe BiCMOS technology has been realized and demonstrated. Responsivities of 9.5 A/W for 670 nm light and of 5.2 A/W for 850 nm light were achieved. Without altering any process step, it is easy to integrate the PTPD with other on-chip circuits to form a high-performance OEIC for fiber-channel (850 nm light) or imaging (visible light) applications. The PTPD is composed of a shallow surface photodetector (SPD) and an integrated SiGe heterojunction bipolar transistor (HBT).