| Popis: |
A two-dimensional general hydrodynamic equation (HDE) solver has been developed. The solver is capable of solving equations from most of the existing hydrodynamic (HD) models. The code is written so that it does not depend on a specific form of the model/parameters which is only introduced at the final stage. Consequently, merits of the different HD models can be studied on the same platform. A new discretization scheme based on optimum artificial diffusivity (OAD) is developed to resolve the numerical instability often existing in the nonlinear, coupled HDE's. The OAD scheme also has an advantage of one formula applies to all. The robustness of this discretization scheme and numerical solution methods is demonstrated by some numerical examples. A practical device simulator must provide not only more accurate physical models but also shorter turn-around. Parallelization is the best strategy to reduce the total elapsed time without sacrificing physical accuracy. Two parallelization approaches, one based on different bias points and the other based on domain-decomposition, are implemented on a network of workstations. Finally, the general HDE solver has been applied to solve several submicrometer SOI-MOSFET's and SiGe HBT's. The predicted device characteristics is highly dependent on the competing effects between the thermal back diffusion and the non-local phenomena related to the energy relaxation. Our numerical results indicate that some kind of experimental verification for the proper choice of HD model is urgently needed. |
