A Subthreshold Swing Model for Thin-Film Fully Depleted SOI Four-Gate Transistors

A mathematical model is developed to determine the subthreshold swing of thin-film fully depleted silicon-on-insulator four-gate transistors (G
⁴
-FETs). The model is developed using a 2-D model of potential distribution that was derived from 2-D Poisson's equation. Study reveals that the subthreshold swing is a strong function of back-surface charge condition and depends on structural parameters of the device. Excellent agreement with 3-D device simulations is observed.