Very High Output Power GaAs-Based HBTs with a Heterogeneously Integrated AlGaN Ultra-Wide Bandgap Collector

We propose to improve power density by integrating wide and ultra-wide bandgap collector regions with AlGaAs/GaAs HBTs. AlGaAs/GaAs HBTs are well-known to demonstrate high-gain performance in mm-wave frequencies, due to the high quality of their emitter-base junction and low base resistance. Our goal is to increase the output power by replacing the traditional (Al)GaAs collector with an ultra-wide bandgap Al(Ga)N collector. To achieve this, we plan to use direct wafer bonding to create our heterostructures, which will then be characterized to assess their power handling capability. Our proposal could lead to the development of future high-power, high-frequency devices at NC State.

Sponsor

Principle Investigators

Spyridon Pavlidis
Frederick Anthony Kish
Zlatko Sitar

More Details

By integrating wide and ultra-wide bandgap collector regions with AlGaAs/GaAs HBTs, we intend to provide a 10x improvement in power density over current state-of-the-art power HBTs. AlGaAs/GaAs HBTs are well-established with proven high-gain performance throughout the mm-wave regime. This is in large part due to the high quality of the AlGaAs/GaAs emitter-base junction and well-controlled p-type doping in the GaAs base, which yield large emitter injection efficiency and low base resistance, respectively. The breakdown voltage, which determines the output power, is limited by the collector region’s critical electric field. We propose to replace the traditional (Al)GaAs collector with an ultra-wide bandgap Al(Ga)N collector in order to significantly boost the power handling of these devices. The proposed heterostructures will be realized via state-of-the-art direct wafer bonding, and will be thoroughly characterized to establish their promise for future high-power, high-frequency devices.