Examination of Temperature Effects on Gate-to-Drain Avalanche Breakdown in GaAs MESFETs (Metal-Semiconductor Field Effect Transistors) by Measuring Light Emission under RF Drive

摘要

This investigation examines temperature effects on avalanche breakdown in GaAs MESFETs to determine if this failure mechanism is accelerated by high temperature life tests. The specific objective is to assess whether the accelerated life test evaluations performed on a GaAs MESFET planned for use in future Defense Satellite Communications System (DSCS) spacecraft have adequately addressed the reliability issues concerning the gate-to-drain avalanche breakdown failure mechanism. This objective was accomplished by adapting an existing analytical model for temperature effects, and using it to predict the variation in avalanche multiplication activity with temperature. To verify this model, it was used to calculate the associated changes in light emissions over temperature which were experimentally validated on one device of the type planned for use by the DSCS program. Once validated, these models were used to evaluate the adequacy of the accelerated temperature life tests. The results of this evaluation indicate that the the avalanche breakdown failure mechanism is decelerated with temperature, and therefore, the effects of avalanche breakdown on the reliability of GaAs MESFETs cannot be determined by accelerated temperature life testing.