Design and investigation of frequency capability of 15kV 4H-SiC IGBT

15 kV 4H-SiC n-channel asymmetric and symmetric IGBTs were designed to minimize the on state and switching power loss. A current enhancement layer was adopted to reduce the forward voltage drop for each IGBTs. For the asymmetric IGBT, it was found that the frequency capability of the device was affected most by adjusting the buffer region parameters such as doping concentration, thickness, and lifetime. For the symmetric IGBT, the p+ substrate doping concentration and drift region lifetime were investigated to obtain maximum switching frequency capability. A comparison of frequency capabilities between power MOSFETs, asymmetric, and symmetric IGBTs has been made. IGBTs provide lower power loss than power MOSFETs up to approximately 7 kHz.