Comparative analysis of gate-dielectric effects on the analog and linearity performance of MoS2-, MoSe2-, and WS2-based FETs

This work investigates the influence of gate dielectric engineering on the analog, RF, and linearity performance of transition metal dichalcogenide field-effect transistors (TMD-FETs). A self-consistent non-equilibrium Green’s function (NEGF)-based simulation framework is employed to analyze MoS 2 -, MoSe 2 -, and WS₂-based FETs integrated with different high-k gate dielectrics. The impact of dielectric materials on electrostatic integrity, carrier transport, transistor efficiency ( g m / I D ), quality factor (Q-factor), and RF linearity metrics is systematically examined. Key device parameters including ON current ( I ON ), OFF current ( I OFF ), current ON/OFF ratio ( I ON / I OFF ), subthreshold swing (SS), transconductance ( g m ), second-order transconductance ( g m2 ), and third-order transconductance ( g m3 ) are evaluated. The results demonstrate that high-k dielectrics significantly enhance gate electrostatic control, resulting in improved ON-state current, reduced SS, enhanced g m / I D efficiency, and superior Q-factor characteristics. Furthermore, the use of high-k dielectrics shifts the peaks of g m2 and g m3 toward lower gate voltages, indicating improved low-voltage RF linearity behavior. Among the investigated materials, WS₂-based FETs exhibit superior transconductance and RF performance characteristics, while MoS 2 -based devices provide an excellent trade-off between power efficiency, nonlinear distortion behavior, and analog/RF characteristics. The findings offer essential insights for optimizing dielectric–channel combinations in next-generation low-power, high-linearity, and RF-oriented nanoelectronic devices.