Polarization Engineered Enhancement Mode High Breakdown Voltage GaN CAVET

In this work we propose and simulate a polarization engineered enhancement mode current aperture vertical electron transistor (P-CAVET). The novelty of the proposed structure lies in using polarization engineering to achieve enhancement mode operation. The current blocking layer (CBL) of proposed P-CAVET is hybrid in nature and consist of an oxide part and AIN part. Aluminum Nitride (AIN) portion of CBL is used to lift the triangular well existing at AIGaN/GaN interface above the Fermi level, thus achieving the enhancement mode operation. The CBL provides better suppression of vertical leakage which improves the breakdown voltage. The proposed structure does not need any p-type doping either for achieving enhancement mode operation or for forming current blocking layer. A 2-D calibrated simulation study has revealed that the proposed device exhibits a threshold voltage of 3.1V and breakdown voltage improvement of 100% over the conventional device CAVET.