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 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. (© 2023 Wiley‐VCH GmbH)