6.5 V High Threshold Voltage AlGaN/GaN Power Metal-Insulator-Semiconductor High Electron Mobility Transistor Using Multilayer Fluorinated Gate Stack

In this letter, the approach of partial AlGaN recess and multiple layers of fluorinated Al2O3gate dielectric is utilized to achieve highest reported positive gate threshold voltage (V_TH) without severe reduction on 2-D electron gas carrier mobility in AlGaN/GaN HEMTs. Guided by the design and verification through analytical model, proper fluorine ions incorporation is made through fabrication. The approach resulted in a highV_THof +6.5 V and competitive drain saturation current (I_DMAX) of 340 mA/mm. Furthermore, low gate leakage current and high breakdown voltage of 1140 V were also demonstrated.