DC and Microwave Characteristics of L-g 20 nm T-Gate Enhancement Mode Al0.5Ga0.5N/AlN/GaN/Al0.08Ga0.92N High Electron Mobility Transistor for Next Generation High Power Millimeter Wave Applications

摘要

In this article, DC and microwave characteristics of a novel 20 nm E-mode Al0.5Ga0.5N/AlN/GaN with Al0.08Ga0.92N back-barrier has been studied by using Synopsys TCAD tool. The device structure is simulated by using Drift-Diffusion transport model at room temperature. The device features are heavily doped (n++ GaN) source/drain regions with Al2O3 passivated device surface and T-gate. L-g of 20 nm HEMT recorded a f(t)/f(max) of 325/553 GHz. The peak drain current density of 3 A/mm is achieved by offering effective conduction band offset by using AlN barrier material associated with back-barrier by enhancing the sheet charge carrier density in 2DEG region (1.1x10(13) cm(-2)) with higher carrier mobility of 1250 (cm(2)/V-s). The T-gate structure with 2 nm thin AlN barrier material reduced the short channel effects (SS = 100 mV/dec and SS = 63 mV/V) by maintaining good aspect ratio (L-g/d = 4.44). The essential key parameter for high power microwave transistor JFoM of 8.775 THz.V is obtained by improving the breakdown voltage (V-BR = 27 V) and f(t) simultaneously. This excellent DC and microwave behaviour of proposed HEMT device is the most suitable candidate for next generation monolithic microwave integrated circuits for high power millimeter wave RF applications.