Microwave power InP/InGaAs/InP double-heterojunction bipolar transistors

The authors report the first demonstration of microwave power performance of an InP-based double-heterojunction bipolar transistor (DHBTs). The DHBT was grown in a low-pressure organometallic chemical vapor deposition (OMCVD) reactor. The growth was carried out at a relatively high temperature of 650 C. The base dopant was Zn. The location of p-n junction near the heterointerface is critical for determining device performance. As a result special attention was paid to the diffusion of the Zn from the base into the adjacent regions. The high growth temperature significantly helped in minimizing the Zn diffusion. A self-aligned process was employed to fabricate small emitter devices. The DHBT exhibited characteristics that satisfy all requirements for microwave power performance including high speed, high breakdown voltage, high current density, and low collector-emitter off-set voltage