We investigate the effect of Negative-Bias-Temperature-Instability on 4H-Silicon Carbide MOSFETs at room and cryogenic temperature and found a large negative threshold voltage shift at T < 250 K. For T < 140 K, both capture and emission follow an almost ideal exponential transient. Cryogenic temperatures reveal fast interface traps, otherwise difficult to probe at relatively high temperatures; we attribute the threshold voltage shift to a high density of hole traps located: 1) close to the SiC valence band and able to emit within the measurement time window; 2) above the SiC valence band, responsible of the slow transient at low temperature. Finally, the extraction of the emission time constant via Capture Emission Time map analysis allowed to extract the activation energy of mechanism 2 (82 meV).

我们研究了在室温和低温下负偏置温度不稳定性对 4H-碳化硅 MOSFET 的影响，并发现在T  < 250 K 时有很大的负阈值电压偏移。对于T < 140 K，捕获和发射都遵循几乎理想的指数瞬态。低温揭示了快速的界面陷阱，否则在相对较高的温度下难以探测；我们将阈值电压偏移归因于位于以下位置的高密度空穴陷阱：1）靠近 SiC 价带并能够在测量时间窗口内发射；2）在SiC价带之上，负责低温下的缓慢瞬态。最后，通过捕获发射时间图分析提取发射时间常数可以提取机制 2 (82 meV) 的活化能。