Novel In-Situ AlN/p-GaN Gate HEMTs With Threshold Voltage of 3.9 V and Maximum Applicable Gate Voltage of 12.1 V

In this article, we demonstrate a novel E-mode HEMT featuring in situ AlN dielectric layer on p-GaN cap layer. Compared with conventional p-GaN gate HEMT, the threshold voltage of in situ AlN/p-GaN gate HEMT shifts from 1.8 to 3.9 V, and the forward gate breakdown voltage is increased from 10.0 to 17.6 V. By considering 10 years’ lifetime at 63% failure level, the maximum applicable gate voltage for AlN/p-GaN gate HEMT reaches a remarkable high value of 12.1 V (E-model), which is much higher than that of 6.1 V for conventional HEMT. In addition, the novel E-mode HEMT exhibits a high ON/OFF ratio of10^9. Experiments demonstrate that E-mode in situ AlN/p-GaN gate HEMT has great potential in power electronics applications.