Degradation Mechanisms of 1200 V 4H-SiC Planar Power MOSFET under Negative HTGB Stress
Journal
Key Engineering Materials
Journal Volume
1054
Start Page
91
End Page
97
ISSN
10139826
Date Issued
2026
Author(s)
Abstract
This study investigates the degradation behavior of 1200 V 4H-SiC planar MOSFETs under negative high-temperature gate bias (HTGB) stress. The devices were stressed at −20 V and 150 °C for 1008 hours. Key electrical parameters, including threshold voltage (Vth) and reverse transfer capacitance (Crss), were monitored to evaluate time-dependent changes. The results reveal a clear two-phase degradation behavior characterized by a transition between electron-dominated and hole-dominated charge injection mechanisms. In the early stage, electron injection via Fowler– Nordheim (FN) tunneling causes a positive shift in Vth and a reduction in Crss. With prolonged stress, partial charge compensation leads to a reversal of the electrical trends. These results demonstrate a time-dependent transition between electron injection and hole injection mechanisms. The findings provide insight into the long-term reliability of planar SiC MOSFETs under negative HTGB stress.
Subjects
Fowler–Nordheim tunneling
high-temperature gate bias (HTGB)
hole injection
reliability
reverse transfer capacitance (Crss)
SiC MOSFET
threshold voltage (Vth)
Publisher
Trans Tech Publications Ltd
Type
journal article