Authors: H. Lou
Affilation: peking university, China
Pages: 667 - 670
Keywords: NEGF, ultra-thin body (UTB), double-gate (DG), nonparabolicity effects (NPE), effective mass approximation (EMA), parabolic quantum-confined masses (PQM)
In this paper, the band-structure of ultra-thin body (UTB) double-gate (DG) MOSFETs is calculated by empirical tight-binding model, and the the nonparabolicity effects are included in the model by the modified Schrödinger equation with the fitting parameters which are extracted from the band-structure by expanding the dispersion relationship in a power series up to the third order. The characteristics of UTB-DG MOSFET current are simulated and the results are compared by the non-equilibrium Green’s function (NEGF) transport theory based on effective mass approximation (EMA), parabolic quantum-confined masses (PQM) and nonparabolicity effect model (NPE). It is shown that the saturation current is overestimated in the models based on EMA and PQM compared with the model including NPE, and the value rises to 4% when Tsi equals to 3nm. The difference between NPE model and PQM model increases with increment of Vg, but less sensitive to Vds.