1.48-kV enhancement-mode AlGaN/GaN high-electron-mobility transistors fabricated on 6-in. silicon by fluoride-based plasma treatment

Abstract

Enhancement-mode AlGaN/GaN high-electron-mobility transistors (HEMTs) were fabricated on a Si substrate by fluorine plasma treatment without pre-etching. The threshold voltage shifted from −8 to 2.3 V, effectively converting the depletion-mode HEMT to the enhancement-mode HEMT. The leakage current was reduced by two orders of magnitude by CF4 plasma treatment. The device exhibited a superior performance with a maximum drain saturation current of 210 mA/mm at VGS = 10 V and a peak gain of 44.1 mS/mm. A low off-state gate leakage current of 10−6 mA/mm, ION/IOFF ratio of approximately 108, and high breakdown voltage of 1480 V were obtained.