Enhanced drain current density in AlGaN/GaN CAVET through multi-channel composite isolation layers

Abstract In this paper, we propose a high-current-density AlGaN/GaN current aperture vertical electron transistor (CAVET) that utilizes multi-channel composite isolation layers. This innovative structure ingeniously incorporates an isolation layer within the current blocking layer, thereby effectively mitigating the depletion effect of P + GaN on the channel. Furthermore, a multi-channel design featuring a SiO 2 channel isolation layer is employed. This design addresses the issue of mutual depletion of electron gas between multiple channels in vertical structures, thereby significantly enhancing the device’s output capability. The results demonstrate that the proposed structure has a threshold voltage ( V th ) of 2.81 V and a drain saturation output current ( I sat.D ) of 3683 mA mm −1 , representing an 188.6% increase over the basic single-channel trench CAVET. Moreover, the breakdown voltage (BV) of the designed device is 2426 V, with a specific on-resistance ( R on,sp ) of 2.90 mΩ·cm 2 . Compared to the basic single-channel trench CAVET, the figure of merit is improved by 63.7%.