Vincenza Di Stefano

Heat generation and transport in nanoscale semiconductor devices via Monte Carlo and hydrodynamic simulations

Purpose – The purpose of this paper is to set up a consistent off‐equilibrium thermodynamic theory to deal with the self‐heating of electronic nano‐devices.Design/methodology/approach – From the Bloch‐Boltzmann‐Peierls kinetic equations for the coupled system formed by electrons and phonons, an extended hydrodynamic model (HM) has been obtained on the basis of the maximum entropy principle. An electrothermal Monte Carlo (ETMC) simulator has been developed to check the above thermodynamic model.Findings – A 1D n+−n−n+ silicon diode has been simulated by using the extended HM and the ETMC simulator, confirming the general behaviour.Research limitations/implications – The papers analysis is limited to the 1D case. Future researches will also consider 2D realistic devices.Originality/value – The non‐equilibrium character of electrons and phonons has been taken into account. In previous works, this methodology was used only for equilibrium phonons.

Modeling heat generation in a submicrometric n+−n−n+ silicon diode

In this paper a hydrodynamic model for electron and phonon transport in silicon semiconductors has been formulated on the basis of the maximum entropy principle to describe off-equilibrium phenomena in submicron devices. One dimensional steady-state simulations of a n+−n−n+ silicon diode have been carried out.

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.

ELECTROTHERMAL TRANSPORT IN SILICON CARBIDE SEMICONDUCTORS VIA A HYDRODYNAMIC MODEL

A hydrodynamic model describing the electron transport in silicon carbide semiconductors, coupled with the heating of the crystal lattice, is presented. It has been obtained by taking the moments of the coupled Boltzmann equations for the electrons and phonons, and by using the maximum entropy principle. The main advantage of this model is that the transport coefficients are explicitly determined. The model makes use of analytic conduction bands, and the main scattering mechanisms in such semiconductor are taken into account. Simulation results in the bulk case are shown.

Modeling thermal effects in submicron semiconductor devices

In this paper an Extended Hydrodynamic Model for the coupled system formed by electrons and phonons has been formulated, in which the problem of the closure for the high-order moments is solved by means of the Maximum Entropy Principle of extended thermodynamics. Simulation results for a 1D n+ - n - n+ silicon diode are presented.

Heat generation in silicon nanometric semiconductor devices

Purpose – The purpose of this paper is to deal with the self-heating of semiconductor nano-devices. Design/methodology/approach – Transport in silicon semiconductor devices can be described using the Drift-Diffusion model, and Direct Simulation Monte Carlo (MC) of the Boltzmann Transport Equation. Findings – A new estimator of the heat generation rate to be used in MC simulations has been found. Originality/value – The new estimator for the heat generation rate has better approximation properties due to reduced statistical fluctuations.

Analysis of Self-Heating Effects in Sub-Micron Silicon Devices with Electrothermal Monte Carlo Simulations

In order to investigate the role of self-heating effects on the electrical characteristics of sub-micron devices, we have implemented a Monte Carlo device simulator that includes the self-consistent solution of the heat transport equation, obtained in the framework of Extended Irreversible Thermodynamics. The lattice temperature is fed back into the electron transport solver through temperature-dependent scattering tables. Simulation results for a n + − n − n + diode are shown.

A hierarchy of hydrodynamic models for silicon carbide semiconductors

Abstract The electro-thermal transport in silicon carbide semiconductors can be described by an extended hydrodynamic model, obtained by taking moments from kinetic equations, and using the Maximum Entropy Principle. By performing appropriate scaling, one can obtain reduced transport models such as the Energy transport and the drift-diffusion ones, where the transport coefficients are explicitly determined.

An extended hydrodynamic model for silicon nano wires

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 equations on the basis of the maximum entropy principle of Extended Thermodynamics, coupled to the Effective Mass and Poisson equations. 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. By using this model, thermoelectric effects have been investigated.

An efficient heat generation rate evaluation with electrothermal Monte Carlo simulations

In this paper we present an improved version of the Electrothermal Monte Carlo method. This modification has better approximation properties due to reduced statistical fluctuations. Simulation results in 2D structures are presented.