Design optimization and analysis of InGaAs-based junctionless Fin type Field-Effect Transistors (FinFETs) with L_G = 10 nm

In this work, we simulated an InGaAs-based junctionless (JL) FinFET by using 3D TCAD simulations for device optimization related to the ITRS. We also investigated the DC and RF characteristics of the FinFET. High-frequency and DC characteristics such as on-state drain current (I_on), off-state drain current (I_off), I_on/I_off rate, subthreshold swing (S), transconductance (g_m), cut-off frequency (f_T), and maximum oscillation frequency (f_max) were considered to optimize the JL FinFET. Through a TCAD simulation to determine the best InGaAs-based JL FinFETs, the following are optimized as suitable parameters: channel length (L_g) of 10 nm, dielectric thickness (t_ox) of 1 nm, channel doping concentration (D_ch) of 9 × 10¹⁸ cm^-3, fin width (W_fin) of 10 nm and fin height (H_fin) of 20 nm. The optimized InGaAs-based JL FinFET demonstrates I_on of 1.57 mA/μm, I_off of 1.5 × 10^-10 A/μm, I_on/I_off rate of 10⁷, and S of 69 mV/dec. When the structure of the InGaAs-based JL FinFET is optimized for DC characteristics, remarkable frequency properties are obtained, such as an f_T of 7 THz and f_max of 13 THz.