Degradation and Mechanism of D-Mode AlGaN/GaN MIS-HEMTs Under the Combination Action of Hydrogen and HTGB Stress

In this article, the effects of hydrogen treatment (HT) and high-temperature gate bias (HTGB) stress on the degradation of AlGaN/GaN metal-insulator- semiconductor (MIS) high electron mobility transistors (HEMTs) were investigated. The dc characteristics show that the device after HT exhibits a negative drift of thresh-old voltage (Vth), an ON-resistance (RON) decrease, a sub-threshold swing (SS) decrease, and a significant increase of drain-source current (Ids) with respect to the fresh one, while the drain-source resistance and gate leakage current hardly change; the C-V curve slightly negative drifted and the saturation capacitance significantly reduced. Further-more, for both the fresh and HT devices, negative shifts of the transfer curves and increases of Ids are observed under a gate bias stress of -10 V, while a gate bias stress of +10 V results in an opposite phenomenon. Similarly, neither drain-source resistance nor gate leakage current exhibits a pronounced change. After HTGB stress, the saturation capacitance of the HT devices increased significantly. The degradation behavior and mechanism of GaN MIS-HEMTs under HT and HTGB stress are analyzed, respectively. The experimental results can provide a useful reference for the design and space application of AlGaN/GaN MIS-HEMTs.