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

We report the performance of an AlInAs/GaInAs/InP DHBT with a new collector design. The base-collector junction was formed with an all arsenide chirped superlattice with linear variation in the average composition. A doping dipole was inserted at the ends of the superlattice to cancel the quasielectric field. 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.