Monte Carlo and hydrodynamic simulation of a one dimensional n+ – n – n+ silicon diode

An improved closure relation - based on the entropy principle - is implemented in a Hydrodynamic model for electron transport. Steady-state electron transport in the "benchmark" n+ - n - n+ submicron silicon diode is simulated and the quality of the model is assessed by comparison with Monte Carlo results

Coupled quantum-classical transport in silicon nanowires

We present an extended hydrodynamic model describing the transport of electrons in the axial direction of a silicon nanowire. This model has been formulated by closing the moment system derived from the Boltzmann equation on the basis of the maximum entropy principle of Extended Thermodynamics, coupled to the Schr¨odinger-Poisson system. Explicit closure relations for the high-order fluxes and the production terms are obtained without any fitting procedure, including scattering of electrons with acoustic and non polar optical phonons. We derive, using this model, the electron mobility

Ballistic charge transport in a triple-gate silicon nanowire transistor

In this paper we investigate the electrostatics and charge transport in a triplegate Silicon Nanowire transistor. The quantum confinement in the transversal dimension of the wire have been tackled using the Schr¨odinger equation in the Effective Mass Approximation coupled to the Poisson equation. This system have been solved efficiently using a Variational Method. The charge transport along the longitudinal dimension of the wire has been considered using the semiclassical approximation, in the ballistic regime

Time-domain simulation of the full hydrodynamic model

A simple upwind discretization of the highly coupled non-linear differential equations which define the hydrodynamic model for semiconductors is given in full detail. The hydrodynamic model is able to describe inertia effects which play an increasing role in different fields of opto- and microelectronics. A silicon $n^+ - n - n^+$ - structure is simulated, using the energy-balance model and the full hydrodynamic model. Results for stationary cases are then compared, and it is pointed out where the energy-balance model, which is implemented in most of today's commercial semiconductor device simulators, fails to describe accurately the electron dynamics. Additionally, a GaAs $n^+ - n - n^+$-structure is simulated in time-domain in order to illustrate the importance of inertia effects at high frequencies in modern submicron devices.Comment: 15 pages, 8 figures, prepared using jnmauth.cl

Evaluating the Impedance Field through several transport models: a comparison

J. APPL. PHYS

A variance-reduced electrothermal Monte Carlo method for semiconductor device simulation

This paper is concerned with electron transport and heat generation in semiconductor devices. An improved version of the electrothermal Monte Carlo method is presented. This modification has better approximation properties due to reduced statistical fluctuations. The corresponding transport equations are provided and results of numerical experiments are presented

Full Hydrodynamic Simulation of GaAs MESFETs

A finite difference upwind discretization scheme in two dimensions is presented in detail for the transient simulation of the highly coupled non-linear partial differential equations of the full hydrodynamic model, providing thereby a practical engineering tool for improved charge carrier transport simulations at high electric fields and frequencies. The discretization scheme preserves the conservation and transportive properties of the equations. The hydrodynamic model is able to describe inertia effects which play an increasing role in different fields of micro- and optoelectronics, where simplified charge transport models like the drift-diffusion model and the energy balance model are no longer applicable. Results of extensive numerical simulations are shown for a two-dimensional MESFET device. A comparison of the hydrodynamic model to the commonly used energy balance model is given and the accuracy of the results is discussed.Comment: 18 pages, LATE

A Hydrodynamic Model for Silicon Nanowires Based on the Maximum Entropy Principle

Silicon nanowires (SiNW) are quasi-one-dimensional structures in which the electrons are spatially confined in two directions, and they are free to move along the axis of the wire. The spatial confinement is governed by the Schrodinger–Poisson system, which must be coupled to the transport in the free motion direction. For devices with the characteristic length of a few tens of nanometers, the transport of the electrons along the axis of the wire can be considered semiclassical, and it can be dealt with by the multi-sub-band Boltzmann transport equations (MBTE). By taking the moments of the MBTE, a hydrodynamic model has been formulated, where explicit closure relations for the fluxes and production terms (i.e., the moments on the collisional operator) are obtained by means of the maximum entropy principle of extended thermodynamics, including the scattering of electrons with phonons, impurities and surface roughness scattering. Numerical results are shown for a SiNW transistor