Reversible off-state breakdown walkout in passivated AlGaAs/InGaAs PHEMTs

The reversible breakdown walkout in the Si₃N₄ passivated AlGaAs/InGaAs pseudomorphic high-electron mobility transistors (PHEMTs) has been observed and investigated. Due to the double passivation processes, the fabricated PHEMTs demonstrated the reversible off-state breakdown walkout without changing device dc and RF performance significantly. This reversible breakdown behavior was induced by on-state stress. By repeating off-state and on-state stress, the breakdown voltages (V_Bs) eventually reached "stable region" or "reverse region" depending on the final stress process. A 2 V difference was observed between these two regions of breakdown.