Silvaco-based electrothermal simulation of 10 kV 4H-SiC PI-N diode under pulsed condition

The application of silicon carbide technology in p-i-n diode has facilitated the development of p-i-n rectifiers up to several kV blocking voltage with a much thinner drift region thickness as compared to its silicon counterpart. This research focuses on the 2D electrothermal simulation of a 10 kV 4H-SiC p-i-n diode model developed using Silvaco ATLAS software. The p-i-n diode structure was designed for 100 A/cm² forward current density with a cell pitch of 16 μm and an active area of 10 μm² Physics-based models were included to account for low-field mobility, carrier-carrier scattering, carrier generation-recombination, avalanche breakdown, and lattice heating. The device model was simulated under steady state and transient conditions. Pulsed simulation of the p-i-n diode was carried out using an RLC ring down circuit to generate a 5 μs wide pulse with peak current densities up to 5000 A/cm². The reverse recovery characteristics of the diode was analyzed for a forward current density of 100 A/cm² and varying turn-OFF dJ/dt to assess the limitation on usable switching frequency. Lattice temperature profile of the p-i-n diode was generated by including heat generation models during transient simulation to identify thermal hot spot formation and areas of possible failure during pulsed operation.