Low frequency noise - based monitoring of the effects of RF and DC stress on AlGaN/GaN MODFETs

The impact of RF and DC stress on AlGaN/GaN MODFETs is investigated by means of DC and low frequency noise measurements. The devices present significant changes in the drain noise current level after DC and RF stress and manifest trends that are almost independent of type of stress. RF and DC stress are found to be differentiable only through the positive shift in the pinch-off voltage, which takes place only after RF stress. Although the findings of this study support those of previously reported investigations in terms of considering the drain access region responsible for current degradation, they demonstrate that RF stress not only causes degradation of drain current but also of other device characteristics.