TCAD Simulation of Breakdown-Enhanced AlGaN-/GaN-Based MISFET With Electrode-Connected p-i-n Diode in Buffer Layer

This paper presents an optimized normally off GaN-based metal-insulator-semiconductor field-effect transistor (MISFET) with an electrode-connected p-i-n diode inserted in the buffer layer, i.e., EC-PIN MISFET, and in which the substrate is removed for the suppression of the vertical leakage current. We provide the simulation results of the proposed MISFET. The EC-PIN MISFET with L
_gd
= 6 μm presents an excellent breakdown voltage of 1400 V, which attributes to the improvement of electric field distribution in the gate-drain region and the suppression of leakage current by EC-PIN. In addition, the specific on resistance of 0.64 mQ · cm
²
and Baliga's figure of merit of 3.08 GW · cm
^-2
are achieved in the optimized EC-PIN MISFET, indicating a good tradeoff between the specific on resistance and breakdown voltage.