AN IMPROVED HYDRODYNAMIC TRANSPORT MODEL FOR SILICON

For the first time, a closed set of hydrodynamic equations for silicon device analysis is obtained with the aid of self-consistent Monte Carlo device simulation data. This set of macroscopic equations is derived without invoking any phenomenological relations such as the Fourier law for heat flow and the Wiedemann-Franz law for thermal conductivity. We have developed this model by taking the first four moments of the Boltzmann transport equation (BTE). This model takes into account the difference between the moments of the collision terms of the BTE both for bulk and inhomogeneous systems. We have also identified the cause of the spurious velocity overshoot sometimes predicted by other models. By introducing different levels of approximation, this system of hydrodynamic equations can be reduced to the conventional hydrodynamic or energy transport equations. This improved model appears to be more accurate than any existing computation for modeling silicon devices.