Effect of Stress Voltage and Temperature on the Reliability of AlGaN/GaN HEMTs for RF and Microwave Application

The mean‐time‐to‐failure (MTTF) of AlGaN/GaN high electron mobility transistor is demonstrated by considering both voltage and temperature dependent electrical degradation in on‐wafer devices. The characteristics of threshold voltage shift (ΔV_T) and gate leakage current (I_{g_leak}) after off‐state step andV_DS = 0 step stress test are reported. The devices under test are being DC stressed (high operation life‐time test) in semi‐on‐state conditions at constant power dissipation of 2 W mm⁻¹for more or less than 200 h until the maximum drain current (I_dmax) drops by 15%. Under low stress voltage (10 V), we find activation energies (E_a) and voltage acceleration factor (γ) to be 0.32 eV and 0.09 V⁻¹, respectively, while increasing stress voltage up to 20 V results in increased activation energies of 0.68 and 0.16 eV. The MTTF is estimated to be 1.16 × 10⁴ h atV_DS = 20 V, while stressing at low bias gives a high MTTF of 2.20 × 10⁴ h atV_DS = 10 V.