FULL NONLINEAR CLOSURE FOR A HYDRODYNAMIC MODEL OF TRANSPORT IN SILICON

We derive, using the entropy maximum principle, an expression for the distribution function of carriers as a function of a set of macroscopi c quantities (density, velocity, energy, deviatoric stress, heat flux) . Given the distribution function, we can obtain a hydrodynamic model in which all the constitutive functions (fluxes and collisional produc tions) are explicitly computed starting from their kinetic expressions . We have applied our model to the simulation of the thermodynamic pro perties of bulk silicon and of some n(+)nn(+) submicrometer Si devices (with several doping profiles and applied biases), obtaining results comparable with Monte Carlo simulations. Computation times are of orde r of few seconds for a picosecond of simulation. [S0163-1829(98)01607- 5].