LAUSR

In this paper, we proposed a novel junction-less Ga2O3 Metal-Insulator-Semiconductor Field Effect Transistor (MISFET) with p-GaN gate, named p-GaN Ga2O3-MISFET. A heavily doped thin layer p-GaN is set in the trench gate region to deeply deplete the n-Ga2O3 channel region owning to the high work function of the p-GaN. Thus, high threshold voltage (VTH) and breakdown voltage (BV) can be obtained even with wide-fin design and low interface charge density (nint), which ensures easy fabrication and stable VTH. Analytical model and experimentally calibrated TCAD simulation confirm that with the increase of fin width (WFin), from 0.1 um to 0.5 um, VTH of p-GaN Ga2O3-MISFET varies from 3.2 V to 2.4 V with nint = -1×1011 cm-2, which is always about 2.2 V higher than those of the conventional junction-less Ga2O3 MISFET (CJL-MISFET). Besides, BV of the CJL-MISFET decreases from ~3400 V to ~45 V with the increase of WFin due to soft breakdown, while BV of the p-GaN MISFET only decreases to 2800 V caused by enhanced electric field at the corner of the trench gate. Moreover, the activation energy and doping concentration (when larger than 3×1019 cm-3) of p-GaN barely affect the VTH. Besides, high VTH is still remained in a common range of interface charge (from 1×1013 cm-2 to 2×1013 cm-2) at the p-GaN/Al2O3 interface.