Total-ionizing dose irradiation induced degradation behavior and mechanism of the Cascode GaN HEMTs

Abstract

In this article, the effects of total ionizing dose (TID) irradiation and the annealing treatment on the degradation of the commercial Cascode GaN high-electron-mobility transistors (HEMTs) were investigated, and low frequency noise method (LFN) was carried out to analyze the defects. The DC characteristics show that the device after TID irradiation with different doses exhibits a negative drift of threshold voltage (V th) and a remarkable increase of drain-source current (I ds) with respect to the fresh one. Meanwhile, with increasing doses of the TID irradiation, the off-state drain leakage current increases, while the drain-source resistance decreases. The gate-lag characteristic gets better for the Cascode GaN HEMTs after TID irradiation. The transfer characteristics, output characteristics, blocking characteristics and capacitance characteristics of the devices can partly be restored by annealing treatment, but there is no pronounced influence on the gate-lag characteristics and drain-source resistance. The trap density extracted by the LFN method decreases in the Cascode GaN HEMTs after TID irradiation. The degradation behavior and mechanism of the Cascode GaN HEMTs under TID irradiation are analyzed. The experimental results may provide a useful reference for the design and space application of the Cascode GaN HEMTs.