Improved power performance of InGaP-GaAs HBT with composite collector

InGaP/GaAs double heterojunction bipolar transistors (DHBTs) with composite collector has been proposed and fabricated to obtain the suitable heterojunction bipolar transistor (HBT) for power amplifiers in wireless communication. The composite collector combines both wide-bandgap (InGaP) and narrow-bandgap (GaAs) materials. In the composite collector, InGaP material provides high breakdown field and thus is able to be employed to reduce thickness of collector while keeping the same breakdown voltage. GaAs materials provides higher electron mobility and thus is used to reduce on-resistance and transit time. In this work, a DHBT with composite collector (DHBT/spl I.bar/C) is presented to demonstrate its improved power performance.