Vertical GaN Transistor with Quasi-Monolithically Integrated HEMT Gate Driver and Sense-CAVET for Current Monitoring

This work shows the co-integration of the lateral GaN technology with a vertical power device, the current aperture vertical electron transistor (CAVET). The experimental proof-of-concept of a large-area CAVET power device controlled by a lateral HEMT push-pull driver stage with current sensing using a sense-CAVET is demonstrated in a double-pulse measurement setup at 40 V, up to 2.4 A, and 500 kHz. The current is mirrored via a sense-CAVET with a small gate width and converted with a transimpedance amplifier. The response time of the current measurement is approx. 60 ns. In addition to the switching waveforms, static measurements of the vertical and lateral devices and switching waveforms are shown. Thus, this GaN CAVET technology demonstrates the possibility of monolithic lateral device integration compared to other vertical device approaches and may enable future vertical GaN power ICs.