A New Degradation Mechanism in High-Voltage SiC Power MOSFETs

Body diode reliability investigation of SiC power MOSFETs

“…An increasing Vf is attributed in some literatures to the basal plane dislocations (BPDs) in the epitaxial layer, which results in formation of stacking faults (SF) upon forward biasing of SiC PiN diode [4,5]. Positive change in Vf is undesirable as it can adversely affect the inverter's performance and efficiency.…”

“…The SFs which are caused as a result of forward biasing of the body diode act as recombination centers. These recombination centers introduce electronic states in the middle of the bandgap, which, in turn, behave as generation centers when the body diode is reverse biased, causing a higher leakage current [4]. In [6], another possible mechanism is discussed for MOSFETs with thin gate oxide layer: is gate-induced ILEAK due to band-to-band tunneling taking place within the depletion region in the gate/drain overlap region when the MOSFET is in the blocking state.…”

Some Critical Materials and Processing Issues in SiC Power Devices

“…8. 2 The on resistance is the slope of the I-V curve near the origin at V GS = 15 V. The degradation in the on resistance of the MOSFET, which is completely dominated by the majority carrier conduction in the drift region, was observed. The tests were repeated on multiple devices, all of which showed similar results.…”

3C-6H transformation in heated cubic silicon carbide 3C-SiC

“…The generation of stacking faults defects in the device active region causes degradation of SiC devices during long-time operation or during heating of the substrate or devices [6][7][8][9][10][11][12][13]. Therefore, power device degradation takes place due to phase transformations in SiC devices.…”