Tunneling Current Variations in Small-Sized Devices Based on a Compact Threshold Voltage Model

Abstract

Accurate modeling of threshold voltage is necessary in the integrated circuit design of strained silicon devices. Thoroughly researching the factors that affect threshold voltage and establishing a more precise threshold voltage model, can provide essential theoretical support for integrated circuit design. By solving a Poisson equation, in this paper, we demonstrate a comprehensive physical model for the threshold voltage of strained Si NMOSFETs using the gradual channel approximation theory and a quasi-two-dimensional analysis. The model investigates the physical effects such as short-channel, narrow-channel, non-uniform doping, and drain-induced barrier lowering effects on the threshold voltage. After substituting the extracted parameters into the model, a comparison was made with experimental results to validate the accuracy and correctness of the established model. Additionally, variations in the tunneling current of small-sized devices were studied. The two models provide essential references for the analysis and design of strained Si large-scale integrated circuits.

Keywords

• strained Si NMOSFET
• threshold voltage
• physical compact modeling
• tunneling current