Switching of GaN CAVET with Quasi-Monolithic Integrated HEMT Gate Driver

In this letter, a vertical GaN power transistor driven by lateral devices fabricated in the same technology is demonstrated. The technology combines a co-integrated large area current aperture vertical electron transistor (CAVET) with high electron mobility transistors (HEMTs) for the realization of the driver on a GaN substrate. The quasi-monolithic integrated driver stage consists of two HEMT devices in a push-pull configuration. The CAVET and HEMTs are characterized, separated, packaged, and measured in a double pulse test setup with inductive load. The voltage signals of the HEMT driver with CAVET are shown in continuous operation up to 5 MHz and extreme duty-cycles. In pulsed operation, switching characteristics and waveforms under load up to 120 V and 4.1 A are shown with turn-on/-off switching times of 17.3/2.8 ns. Finally, this work demonstrates a GaN technology that combines the functional integration of a driver stage with a vertical power transistor and thus opens the pathway to continue lateral GaN power integration in vertical device concepts.