Design approach for lateral optimization of GaN CAVETs: A static characteristics study

This paper demonstrates a fabless design approach for the lateral optimization of a GaN current aperture vertical electron transistor (CAVET). To this end, the length of the current blocking layer (CBL) has been scaled to exhibit the influence of current aperture length on the static characteristics of GaN CAVET e.g. threshold voltage (V_th), on-state resistance (R_ON), and breakdown voltage (V_BR) and C-V characteristics. Results conclude that the on-state resistance decreases with an increase in aperture length for a given length of the device. Devices with large aperture lengths are additionally susceptible to breakdown at low voltages. This observation illustrates a critical trade-off between the on-state resistance and breakdown voltage for different aperture lengths. Considering this trade-off, optimizing aperture length maximizes Baliga's Figure of Merit (BFOM) for power application.