Simulation and experiment research on high electron mobility transistor microwave damage

The damage process and mechanism of the typical AlGaAs/InGaAs structure high electron mobility transistor by injection of 1 GHz microwave signals from the gate were studied with TCAD based on the distribution of the space charge density, electric field, current density and temperature. The results showed that the gate current rapidly increased because of avalanche breakdown which was 4 orders higher than the gate leakage current under small signals and the gate finger was extremely easy to burn and melt by such high current in the positive semi-cycle of microwave signals; the internal peak temperature of the device appeared between the InGaAs channel and gate near the source below the gate; when the amplitude of the microwave signals was high enough, during the fall time of the positive semi-cycle, the second breakdown occurred below the central gate inclining to the drain which caused double-peak phenomenon of the gate current, and the internal peak temperature of the device shifted to the above position and surpassed the GaAs melting point. Failure analysis of high electron mobility transistor devices damaged by microwaves was carried out with scanning electron microscope and the simulation results were well consistent with the experiment results.