Design and Analysis of P-GaN/N-Ga2O3 Based Junction Barrier Schottky Diodes

This article proposes a new junction barrier Schottky diode (JBSD) design based on P-GaN/N-Ga2O3 heterojunction with faster switching characteristics and higher breakdown ability than the traditional two-terminal power switches. Calibrated models have been used for technology computer-aided design (TCAD) simulations of the proposed JBSD after a comprehensive review of various physical models and model parameters in the present literature. Analysis in terms of static and transient behavior for a varying proportion of PN area to the Schottky contact area (PN:SBD ratio) was looked upon for the JBSD. With the increase of PN:SBD ratio, the reverse voltage handling capability increased as expected, but the reverse recovery time and maximum reverse recovery current decreased. This might be counterintuitive initially, as with an increase in PN:SBD ratio, the PN behavior would dominate over SBD, and slower transient behavior is expected. However, due to redistribution of electric field and the reduction in depletion capacitance across the JBSD with increase in PN:SBD ratio, JBSD with PN:SBD ratio of 8 gives us a breakdown at 1890 V and a switching time of 9.72 ns. Furthermore, a comparison of the transient response with state-of-the-art SiC Schottky diode reveals the efficiency of the proposed structure in terms of reverse recovery parameters to be significantly better, translating to 7.4 times lower power losses at higher frequencies. Overall, the design and analysis presented here suggest the promising potential of P-GaN/N-Ga2O3 vertical devices for high-voltage and fast switching applications.