Design optimization of ultra-wide-bandgap vertical power diodes with self-heating

Abstract

Abstract: In order to determine how material characteristics percolate up to system-level improvements in power dissipation for different wide-bandgap (WBG) and ultra-wide-bandgap (UWBG) material systems and device types, we have developed an optimization tool for power diodes. This tool minimizes power dissipation for a given operational regime for a variety of device types and materials including self-heating due to thermal transport. The tool has been modified to include the UWBG-specific effects of incomplete ionization and space charge limited conduction (SCLC). We have carried out optimizations for a wide range of system operating points to determine the regimes for which certain power diode materials/devices are favored. We present results comparing SiC merged PIN Schottky (MPS) diodes to PIN and Schottky barrier diodes (SBDs) made from diamond, β-Ga2O3, GaN, AlN, and Al0.85Ga0.15N. The results of this work show that AlN and diamond are preferred for high voltages and frequencies under most operating conditions.