Impact of Proton Energy on Displacement Damage and Total Ionizing Dose in SiC Vertical Power MOSFETs

The impact of proton energy on total ionizing dose (TID) and displacement damage (DD) effects has been investigated in commercial 4H-SiC vertical power MOSFETs at ultra-high doses. Devices were irradiated with 1 and 3 MeV protons, which resulted in different penetration ranges of the primary particles. The corresponding peak in non-ionizing energy loss (NIEL) is located in the epitaxial region for 1-MeV protons and in the substrate of the device for 3-MeV protons. In parallel, deep-level transient spectroscopy (DLTS) was performed on irradiated 4H-SiC wafers to analyze the formation of electrically active defects produced by protons of the same energies. A correlation between electron trap concentration and effective doping reduction was observed, confirming the role of these defects in carrier compensation and their direct impact on the electrical degradation observed in the commercial SiC power MOSFETs.