High-performance microwave AlGaAs-InGaAs Pnp HBT with high-DC current gain

摘要

An Pnp heterojunction bipolar transistor (HBT) which had among the highest reported values of f/sub T/( approximately 23 GHz) and f/sub max/( approximately 40 GHz) employed a heavily doped InGaAs pseudomorphic base. However, this HBT had very low values of DC current gain (>or=4). Pnp microwave HBTs with a modified base design are reported. These HBTs not only achieve similar high-frequency performance, but also attain dramatically higher current gain values approximately 90.