Modeling and performance evaluation of wide bandgap semiconductors devices for high power applications

Modeling of the drift region properties of 4H-Silicon Carbide (4H-SiC) and Gallium Nitride (GaN) based Schottky rectifiers and power Metal Oxide Semiconductor Field Effect Transistor (MOSFET) to achieve breakdown voltages ranging from 200 to 5000 V is presented. Schottky rectifiers rated at 1000 V and 3000 V are simulated and the characteristics of the 4H-SiC and GaN devices are compared with those of Si devices. The specific on-resistance Ron,sp of 4H-SiC and GaN MOSFET is at least two and three orders of magnitude smaller than the corresponding on-resistance for a Si device, respectively. 4H-SiC and GaN Schottky rectifiers rated for 5000V can deliver on-state current density of 100 A/cm2 at room temperature with a forward drop of 1.72V and 1.29V, respectively because of very low drift region resistance. A thermal analysis, based on a junction temperature limit, as determined by packaging considerations, showed that 5000V GaN MOSFET and Schottky rectifier dies would be approximately 17 and 85 times smaller than corresponding Si devices. 4H-SiC MOSFET and Schottky rectifier rated for 5000V dies would be approximately 12 and 83 times smaller than the corresponding Si devices. This thermal analysis indicates that 4H-SiC and GaN devices would show correct operation at higher temperatures and higher breakdown voltages than the conventional Si devices.