Effect of fluorinated graphene insulator on AlGaN/GaN MIS-HEMTs as gate dielectric

摘要

We investigate the performance of AlGaN/GaN metal-insulator-semiconductor high electron mobility transistors (MIS-HEMTs) by inserting a fluorinated graphene insulator. It is found that the interface-state density of the sample with fluorinated graphene (5.8 x 10(13)-8.7 x 10(11) eV(-1)-cm(-2)) was lower than that without fluorinated graphene (1.1 x 10(14)-8.1 x 10(12) eV(-1)-cm(-2)) and exhibits better properties, including higher saturation drain current (I-sat), lower on-resistance (R-on), smaller hysteresis of threshold voltage (Delta V-th), and better current collapse suppression. Furthermore, the inserted fluorinated graphene could increase the activation energy of surface leakage current, which is verified by the analysis of leakage current. Our results suggest that the fluorinated graphene insulator can lessen interface-state density at the shallow energy levels by the interface-state density decrement and the activation energy increment.