Bipolar Degradation monitoring of 4H-SiC MOSFET Power Devices by Electroluminescence Measurements

Expansion and contraction of Shockley type stacking faults (SF) due to the glide of basal plane dislocations are reported for the first time in a commercial 4H-SiC MOSFET bare die rated at 100A/1.2kV. Electroluminescence of the laboratory fabricated power MOSFET body diode is measured to detect the bipolar degradation which provides firm evidence of the presence of a 3C- like regions affected by SF. Accelerated bipolar degradation tests were performed on the device and it was found that the on-resistance which is a key indicator of the degradation level, increased by 15.6 % during the first stress while it decreased by 6.9 % in the second stress. Other related SiC material defects were as well detected. The electroluminescence spectra is an excellent tool for monitoring SiC power devices deterioration related to material defects without performing destructive tests such as SEM.