Normally Off AlGaN/GaN MIS-High Electron Mobility Transistors Fabricated by Using Low Pressure Chemical Vapor Deposition Si3N4 Gate Dielectric and Standard Ion Implantation

This paper presents a fabrication technology of enhancement-mode (E-mode) AlGaN/GaN metal insulator semiconductor high electron-mobility transistors (MIS-HEMTs) using 10 keV fluorine ion implantation. An 8 nm low pressure chemical vapor deposition (LPCVD) silicon nitride layer was deposited on the AlGaN as gate dielectric and energy-absorbing layer that slows down the high energy (10 keV) fluorine ions to reduce the implantation damage. The E-mode MIS-HEMTs exhibit a threshold voltage as high as 3.3 V with a maximum drain current over 200 mA/mm (250 mA/mm for depletion-mode (D-mode) MIS-HEMTs) and a high on/off current ratio of 109. Meanwhile, the E-mode MIS-HEMTs dynamic RON is only 1.53 times than the static RON after off-state VDS stress of 500 V.