4H-SiC has been an excellent material for power switching devices because of its wide bandgap and high breakdown field. SiC power MOSFETs below 10 kV have been successfully developed and fabricated in the past decade. However, MOSFETs blocking above 10 kV face the problem of high on-state resistance. This problem cannot be solved within MOSFET itself.

P-channel IGBTs, a new type of SiC power transistors that provide a solution for 20 kV applications, are studied in this research. Extensive numerical simulation is carried out to demonstrate the device performance and to optimize the device design. The first high performance 20 kV P-IGBT is successfully fabricated. These P-IGBTs exhibit significant conductivity modulation in the drift layer, which greatly reduces the on-state voltage drop. Assuming a 300 Watt per square centimeter power package limit, the maximum currents of the experimental P-IGBTs are 1.24x and 2x higher than the theoretical maximum current of a 20 kV MOSFET at room temperature and 177°C, respectively.