ION INDUCED CHARGE COLLECTION IN GAAS-MESFETS AND ITS EFFECT ON SEU VULNERABILITY

An ion induced charge collection study, using an array of GaAs enhancement-mode MESFET geometries has identified two primary excess charge collection effects, a fringe field effect and a gated channel effect. The introduction of a buried p-layer was found to suppress the fringe field effect, which resulted in a reduction in the maximum excess charge collected. The LET threshold for SEU was similar for both processes. For the devices used in this study, the results suggest that the gated channel effect is primarily responsible for the low SEU LET threshold.