Determination of the effective critical breakdown field for Si, wide, and extreme bandgap semiconductor superjunction devices

Abstract

Designing high voltage superjunction (SJ) power devices with wide bandgap and extreme bandgap semiconductors, when compared to silicon, can enhance the trade-off between RON,sp and BV significantly, due to their >10× higher avalanche breakdown electric field. Nevertheless, because of the difference in the breakdown field profile and ionization path length, the effective breakdown field for these semiconductor SJ devices has not been determined theoretically. Consequently, we estimate and compare the effective critical breakdown electric field for SJ device structures in Si, 4H-SiC, 2H-GaN, β-Ga2O3, diamond, and AlN using Technology Computer Aided Design TCAD simulation. We also establish its dependence on the SJ devices’ structural parameters, such as the pillar thickness. Furthermore, we also quantitatively compare the on-state performance of these SJ devices, including their thermal capabilities, using a paramount figure-of-merit to underscore the potential improvement possible.