Computational macroscopic approximations to the one-dimensional relaxation-time kinetic system for semiconductors

We study comparisons of deterministic computational methods for one-dimensi onal relaxation charged transport in submicron channel devices. Our analysi s focuses on the appropriate macroscopic approximations under regimes assoc iated to different devices with similar geometries. We show, when taking st andard parameters corresponding to Si devices, that the kinetic one-dimensi onal relaxation model can be approximated by a multi-fluid domain decomposi tion technique that incorporates classical drift-diffusion equations with c orrections in the current. In addition, when considering physical dimension s corresponding to GaAs devices, the technique requires new hydrodynamics t hat we propose and compute. Our comparison involves detailed computations o f local distribution function solution of the kinetic equation, its first t hree moments compared with the computed fluid variables, and the presentati on of all corresponding current-voltage characteristic curves. (C) 2000 Els evier Science B.V. All rights reserved.