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A gate-drain overlapped FinFET, which provides low leakage current (I OFF ) , high I ON current, and high I ON / I OFF ratio with low subthreshold swing ( SS ), is proposed. To have better physical inside of the proposed structure, a 3-D analytical model of surface potential is derived by solving Poisson's equation in the channel and overlap regions using superposition principle. Using the surface potential, a closed form expression for the threshold voltage is also derived. Both the surface potential and threshold voltage models show good agreement with TCAD simulation data for different values of channel lengths, fin heights, fin widths, gate work functions, and channel concentrations. Furthermore, the performance of the device is evaluated in digital circuit applications and interestingly, no overshoot and undershoot are observed in the transient characteristics in case of a low power inverter. Investigation shows that the gate-drain overlap region influences the device characteristics significantly. [ABSTRACT FROM AUTHOR]

This paper presents an analytical model of threshold voltage (Vth) and subthreshold swing (S) for a tri-gate (TG) heterojunction n-FinFET. The heterojunction is formed between the silicon source and germanium channel. The electrical parameters are analyzed by solving three-dimensional (3-D) Poisson's equation with the aid of superposition principle. Based on the 3-D potential function and the minimum potential position in the channel, Vth and S are modeled. The model is validated against TCAD simulations. The modeled Vth and S are verified for variation of channel length (Lf), workfunction, oxide thickness (tox), drain-to-source voltage (VDS), gate-to-source voltage (VGS), channel concentration and fin width (Tfin). The models developed for Vth and S in the TG heterojunction FinFET are evaluated for its homojunction equivalent silicon structure, and found to exhibit excellent agreement with TCAD results. [ABSTRACT FROM AUTHOR]