A numerically efficient method for the hydrodynamic density-gradient model

We propose a quantum transport model that is a hydrodynamic extension of the density-gradient model. The governing equations are derived from the moments of the Wigner distribution function and their forms are suitable for the conventional device simulation program. The model is discretized by the control volume method with nonlinear discretizations for the electron and energy flux equations. We also developed a boundary condition for the Si/SiO/sub 2/ interface that includes the electron wavefunction penetration into the oxide to obtain more accurate C-V characteristics. As an application, we studied a 25 nm NMOSFET device. Compared with the semiclassical models, the new model predicts reduced gate capacitance about 20% and increased subthreshold slope and DIBL about 16% and 46% respectively. Compared with the density-gradient model, the on-current is increased up to 26% due to the nonlocal transport effect.