Identifying a Double-Energy-Level Trap Center in a GaN HEMT by Performing Three-Stage Pulse Measurements

The results of measurements performed on a GaN high electron-mobility transistor (HEMT) by two different pulse-measurement techniques are presented. By performing two-stage pulse measurements, two distinct current-injection mechanisms responsible for triggering the trapping process are identified. By performing three-stage pulse measurements, the trap center at which the trapping process occurs is identified to be a double-energy-level trap center, which is a trap center with two distinct energy levels between which there is an interaction. This result has a significant impact on the design of more accurate large signal models for GaN HEMTs.