Numerical analysis on the performance enhancement in AlGaN/GaN vertical CAVET with InGaN/AlN/InGaN hybrid current blocking layer

Abstract In this paper, we propose an enhanced superjunction AlGaN/GaN vertical current aperture vertical electron transistor (CAVET) that integrates a novel hybrid InGaN/AlN/InGaN current blocking layer (CBL) situated above the P-column, directly beneath the channel. The incorporation of InGaN substantially elevates the device’s saturation output current by introducing a subchannel beneath the AlGaN/GaN heterojunction conducting channel. Nonetheless, the introduction of AlN engenders a two-dimensional hole gas of opposite polarization direction via the GaN/AlN heterojunction, which aids in depleting the two-dimensional electron gas within the channel, thereby mitigating the issue of negative threshold voltage (V _th) bias occasioned by the subchannel introduced by InGaN. The outcomes demonstrate that the maximum saturation output current (I _d) for the proposed architecture is 361.5 mA mm⁻¹, with a V _th of 1.63 V, marking increases of 98.6% and 0.08% over the traditional superjunction CAVET, respectively. Simultaneously, the breakdown voltage (V _br) of the designed device is recorded at 12 064 V, and the specific on-resistance (R _on,sp) is 6.45 Ω·mm, showcasing a enhancement figure of merit of 32.9% in comparison to the traditional superjunction CAVET.