Microwave Nanosecond Pulse Burnout Properties of GaAs MESFET´s

Microwave nanosecond pulse burnout data have been measured at 9.3 GHz for three commercially available 1-mu m gate MESFET´s. Values for the incident pulse power required to cause burnout are concentrated in the ranges 4-10 W for 10-ns pulses, 12-25 W for 3-ns pulses, and 15-30 W for 1.5-ns pulses. The corresponding values for the absorbed microwave pulse energy required to cause burnout are concentrated in the ranges 0.3 to 0.6 ergs for 10-ns pulses, 0.2-0.4 ergs for 3-ns pulses, and 0.2-0.35 ergs for 1.5-ns pulses. Two dominant failure modes in overstresed MESFET´s have been observed. One is a gate-to-source low-resistance path (5-25 Omega) which frequently is correlated with metal migration (mainly gold) from the source metallization to the gate metallization. This failure mode was dominant when MESFET´s failed at lower power Ievels as at 10 ns. The other dominant failure mode is a reduction in I_DSS or a drain-to-source short which is correlated with massive damage in the channel region between the source and gate metallizations. This failure mode was dominant when MESFET´s failed at high power levels as at 1.5 ns.