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 (Δ V T ) and gate leakage current ( I g_leak ) after off‐state step and V 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 −1 for 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 × 10 4 h at V DS = 20 V, while stressing at low bias gives a high MTTF of 2.20 × 10 4 h at V DS = 10 V.