The Effect of the Gate-Connected Field Plate on Single-Event Transients in AlGaN/GaN Schottky-Gate HEMTs

A focused pulsed X-ray beam is used to determine how the redistribution of the electric field by the gate-connected field plate affects single-event transient (SET) susceptibility of an AlGaN/GaN Schottky-gate HEMT on SiC. SETs generated by scanning the X-ray beam across the HEMT depend strongly on the presence of the field plate, radiation strike location, bias conditions, and X-ray photon energy. For the particular HEMT we tested, the gate-connected field plate reduces the electric-field strength near the edge of the gate by a factor of approximately 2, which results in faster decaying transients and less collected charge.