| A new semiconductor device simulator based on the Lei-Ting hydrodynamic balance equations is presented here. Unlike other hydrodynamic equation based approaches to device modeling, where the various relaxation rates are imported from Monte Carlo calculations or simply assumed to be constant, our approach includes scattering in the form of frictional force functions due to electron-impurity and electron-phonon interaction and an energy loss function due to electron-phonon interaction. These quantities are calculated within the simulation process itself, as functions of the electron drift velocity, electron temperature, as well as the electron density, without an outside, separate Monte Carlo procedure. Thus, besides the usual advantages of traditional hydrodynamic simulation approaches, the present method enjoys the added convenience of self-contained treatment of scattering.; This thesis reports on a systematic implementation of the Lei-Ting hydrodynamic balance equations as a sophisticated, versatile device simulation package, capable of 1D, 2D device modeling tasks encountered by device designers today. In addition to steady-state modeling, transient device simulations based on the new hydrodynamic model are also described. Without any complicated mathematics, a new decoupled method with a relatively large time step has been applied to the transient simulation. The time discretization algorithm for our transient simulator is based on the Crank-Nicolson method for time discretization, and for the algorithm of the time step selection we used the local error to determine the size of each time step.; We have applied our hydrodynamic balance model to {dollar}rm nsp{lcub}+{rcub}{dollar}-n-n{dollar}sp{lcub}+{rcub}{dollar} ballistic diode, MESFET and MOSFET. The results are in general accord with other methods, such as classical hydrodynamic models and Monte Carlo models. Moreover, the savings of the computational time are expected. |
