Three-terminal off-state breakdown in AlGaAs/GaAs power HFETs: a temperature-dependent analysis of the gate reverse current

The physical phenomena underlying the drain-gate breakdown of heterostructure FETs for microwave power applications are still not completely understood. On the other hand, power FETs with large drain-gate breakdown voltage are pivotal components for the booming market of wireless and personal communications, since they are required in handset and portable units as well as in base station amplifier circuits. A detailed study of their breakdown behavior is thus extremely urgent and important for the industrial development and exploitation of these devices. In this framework, we give in this abstract an analysis of the gate reverse current under off-state breakdown conditions, which are likely the most critical for the reliability of GaAs-based FETs operated in class AB or B for high-efficiency power amplification. A study of the temperature dependence of the gate reverse current allows us to identify the physical phenomena taking place in the drain-gate region at different values of the reverse bias and to pinpoint the mechanism giving rise to off-state breakdown.