Quantum Analytical Modeling of Inversion Charge and Threshold Voltage in Modified Bi-Level FinFET (BL-FinFET)

Abstract

A modified Bi-level FinFET is proposed and its salient features over conventional-FinFET (C-FinFET) are presented. For ultra-thin structure, its working principle incorporating quantum effect was modeled by solving 3D Poisson's and 2D Schrödinger's equation self consistently. 3D Poisson's equation was solved to find the potential distribution in the channel region. Equations for wave function and energy quantization were developed by solving Schrödinger's equation. Using quantized energy level, the expression for the inversion charge in subthreshold region was also developed. Finally, the threshold voltage (V T ) was modeled by equating modeled inversion charge with the threshold charge obtained from TCAD simulator. The effects of device dimensions on threshold voltage were thoroughly studied at various drain bias values. The developed model was validated for Si, Ge, and GaAs channels. Model results verified against ATLAS SILVACO simulator showed very good agreement.