A novel insight of pBTI degradation in GaN-on-Si E-mode MOSc-HEMT

For the first time, ultrafast AC pBTI measurements are applied to GaN on Si E-mode MOSc-HEMT and compared to DC pBTI. Full recess Al
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/GaN MOS gate is submitted to AC signals with various frequencies, duty factors and stress times. The degradation and relaxation characteristics are then modeled through a RC model combined to a CET map and fitted to experimental data. This map reveals the presence of two trap populations, also observed through ΔVth degradation kinetics. Acceleration factors (gate voltage and temperature) are estimated as well as TTF (Time to Failure) under AC conditions and show an extended lifetime compared to DC stress conditions. Finally dynamic variability is studied and indicates that our devices are ruled by normal distributions.