A methodology to delimit the on-state safe operating area of GaAs MESFET for non linear applications

We have described and applied a methodology to delimit the on-state safe operating area of MESFETs driven under non linear operating conditions. This methodology consists in applying accelerated DC step stress in regions which can be reached by the Vds and Vgs sweeps in overdrive conditions. This safe operating area defined from accelerated DC stresses, is more severe than the one defined from accelerated RF stresses. The safe operating area defined in this work corresponds to an on-state operation of the transistor. But, in overdrive conditions, the sweeps of Vgs can reach high negative values. Hence, by applying DC stresses with off-state bias conditions that is with high gate-drain voltage, we define a safe operating area for the whole non linear load line of the transistor. This work, deals with a GaAs MESFET technology, but the method can be extended to other technologies like GaAs PHEMT or GaAs DCFET.