[TuP3C] Power Devices

2:00 PM - 4:00 PM JST(5:00 AM - 7:00 AM UTC)

[TuP3C-17 LN] Bidirectional V_TH Shift in p-GaN HEMTs under Off-state AC-BTI at Cryogenic Temperature

〇Chuan Song¹, Wen Yang¹, Huaxing Jiang¹, Bin Li¹ (1. South China Univ. of Tech. (China))

This study investigates the reliability of p-GaN HEMTs under off-state AC-BTI stress at 10 K. Compared to DC-BTI, a reduced bidirectional threshold voltage (V_TH) shift is observed under AC stress, suggesting prior DC-based evaluations may underestimate cryogenic operational reliability. We demonstrate that increasing the stress frequency suppresses the late-stage negative V_TH shift by restricting the field-assisted de-trapping window for frozen traps. Furthermore, complete post-stress V_TH recovery indicates the degradation is dominated by reversible charge trapping and de-trapping. Energy band analysis reveals these competing mechanisms stem from the dynamic alternation of asymmetric hole and electron trapping/de-trapping during AC operation.