AlInAs/GaInAs/InP double heterojunction bipolar transistor with a novel base-collector design for power applications

We report the performance of an InP-based DHBT with a new collector design. The base-collector junction was formed with an all arsenide chirped superlattice. The elimination of the potential barrier at the base-collector junction has been achieved by properly combining the electrostatic potential arising from the ionized dopants in the space charge region and the energy band profile of the CSL. The conduction band offset between AlInAs and InP enabled hot electrons to be launched into the InP collector. The new design resulted in an excellent combination of speed and breakdown voltage with superior microwave power performance at X-band. Output power of 2 W (5.6 W/mm) with 70% power-added-efficiency at 9 GHz was achieved.