Comparison of Different Approaches used for Estimation of Electrostatics in UTB devices

Abstract

With the scaling of SOI channel and oxide thicknesses in Ultra-thin Body (UTB) devices, Quantum Confinement Effects (QCEs) becomes significant and need to be considered for accurate estimation of electrostatics parameters such as electron density inside the channel. In this work, we propose to use a <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$sp^{3}d^{5}s^{\ast}$</tex> Tight-Binding (TB) scheme by suitably selecting the significant k-points around the band minima, which makes this approach computationally efficient while being accurate to account for Quantum Confinement Effects. Thus through comparison of electrostatics obtained from other approaches, such as Effective Mass Approximation (EMA) used by SCHRED and Density Gradient Approach (DGM) used in TCAD, we show the importance of using the TB based approach as it is shown to be far more accurate in considering Quantum confinement effects compared to other existing approaches.