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Article
Publication date: 1 June 2003

Angelo Marcello Anile, Salvatore Spinella and Salvatore Rinaudo

Tolerance analysis is a very important tool for chip design in the microelectronics industry. The usual method for tolerance analysis is Monte Carlo simulation, which, however, is…

Abstract

Tolerance analysis is a very important tool for chip design in the microelectronics industry. The usual method for tolerance analysis is Monte Carlo simulation, which, however, is extremely CPU intensive, because in order to yield statistically significant results, it needs to generate a large sample of function values. Here we report on another method, recently introduced in several fields, called stochastic response surface method, which might be a viable alternative to Monte Carlo simulation for some classes of problems. The application considered here is on the tolerance analysis of the current of a submicrometer n+nn+ diode as a function of the channel length and the channel doping. The numerical simulator for calculating the current is based on the energy transport hydrodynamical model introduced by Stratton, which is one of the most widely used in this field.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 22 no. 2
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 2 March 2012

Giovanni Mascali and Vittorio Romano

This paper intends to present a hydrodynamical model which describes the hole motion in silicon and couples holes and electrons.

Abstract

Purpose

This paper intends to present a hydrodynamical model which describes the hole motion in silicon and couples holes and electrons.

Design/methodology/approach

The model is based on the moment method and the closure of the system of moment equations is obtained by using the maximum entropy principle (hereafter MEP). The heavy, light and split‐off valence bands are considered. The first two are described by taking into account their warped shape, while for the split‐off band a parabolic approximation is used.

Findings

The model for holes is coupled with an analogous one for electrons, so obtaining a complete description of charge transport in silicon. Numerical simulations are performed both for bulk silicon and a p‐n junction.

Research limitations/implications

The model uses a linear approximation of the maximum entropy distribution in order to close the system of moment equations. Furthermore, the non‐parabolicity of the heavy and light bands is neglected. This implies an approximation on the high field results. This issue is under current investigation.

Practical implications

The paper improves the previous hydrodynamical models on holes and furnishes a complete model which couples electrons and holes. It can be useful in simulations of bipolar devices.

Originality/value

The results of the paper are new since a better approximation of the band structure is used and a description of both electron and hole behavior is present, therefore the results are of a certain relevance for the theory of charge transport in semiconductors.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 31 no. 2
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 1 March 2005

Giovanni Mascali and Vittorio Romano

On the basis of the maximum entropy principle, seeks to formulate a hydrodynamical model for electron transport in GaAs semiconductors, which is free of any fitting parameter.

Abstract

Purpose

On the basis of the maximum entropy principle, seeks to formulate a hydrodynamical model for electron transport in GaAs semiconductors, which is free of any fitting parameter.

Design/methodology/approach

The model considers the conduction band to be described by the Kane dispersion relation and includes both Γ and L valleys. Takes into account electron‐non‐polar optical phonon, electron‐polar optical phonon and electro‐acoustic phonon scattering.

Findings

The set of balance equation of the model forms a quasilinear hyperbolic system and for its numerical integration a recent high‐order shock‐capturing central differencing scheme has been employed.

Originality/value

Presents the results of simulations of n+ ‐nn+ GaAs diode and Gunn oscillator.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 24 no. 1
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 6 March 2009

A.M. Blokhin and R.S. Bushmanov

The purpose of this paper is to reply to the following question: do there exist piecewise smooth solutions to the 2D MEP hydrodynamical model of charge transport in semiconductors…

Abstract

Purpose

The purpose of this paper is to reply to the following question: do there exist piecewise smooth solutions to the 2D MEP hydrodynamical model of charge transport in semiconductors with smooth parts separated by a surface of strong discontinuity?

Design/methodology/approach

A standard approach is used to obtain jump conditions for the balance equations under consideration.

Findings

For the balance equations of charge transport in semiconductors based on the maximum entropy principle Rankine‐Hugoniot jump conditions were derived and studied. Considering the important case of planar discontinuity, the authors discuss the legitimacy of the introduction of surface charge and surface current in the Rankine‐Hugoniot jump conditions.

Research limitations/implications

The jump conditions are derived for the balance equations written for the case of the parabolic approximation of energy bands. However, it is possible also to perform the analysis of corresponding jump conditions for the case of Kane dispersion relation approximation.

Originality/value

The paper presents derivation and study of Rankine‐Hugoniot jump conditions for the 2D MEP hydrodynamical model of charge transport in semiconductors.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 28 no. 2
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 1 December 2001

Salvatore Fabio Liotta

In this paper an asymptotic solution of the spherical harmonics equations describing the charge transport in semiconductors is found. This solution is compared with a numerical…

Abstract

In this paper an asymptotic solution of the spherical harmonics equations describing the charge transport in semiconductors is found. This solution is compared with a numerical solution for bulk silicon device. We also indicate application of this solution to the construction of high field hydrodynamical models.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 20 no. 4
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 1 April 1992

G.V. Gadiyak, J.L. Korobitsina and V.I. Kranarenko

Computer code complex for the thermal oxidation of silicon is presented. There are one‐dimensional model and two‐ dimensional models:the model of viscoelastic oxide and the…

Abstract

Computer code complex for the thermal oxidation of silicon is presented. There are one‐dimensional model and two‐ dimensional models:the model of viscoelastic oxide and the hydrodynamical models — an ideal fluid and a viscous fluid models. If nitride mask is absent, a one‐dimensional model is used.The influence of an induced stress on the diffusion and reaction is taken into account.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 11 no. 4
Type: Research Article
ISSN: 0332-1649

Article
Publication date: 1 March 1999

A.M. Blokhin and A.A. Iohrdanidy

A mathematical gas dynamic model for semiconductor devices is numerically analysed. The well‐known ballistic diode problem is taken as an example.

Abstract

A mathematical gas dynamic model for semiconductor devices is numerically analysed. The well‐known ballistic diode problem is taken as an example.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 18 no. 1
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 1 April 1993

A.D. Sadovnikov and D.J. Roulston

With decreasing vertical dimensions of the bipolar transistor (BJT), non‐local effects of nonuniform electron temperature should have a significant effect on the BJT…

Abstract

With decreasing vertical dimensions of the bipolar transistor (BJT), non‐local effects of nonuniform electron temperature should have a significant effect on the BJT characteristics. These effects can be simulated using a hydrodynamic (HD) model of the BJT, in which the equation of energy balance is added to the set of Poisson's and continuity equations.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 12 no. 4
Type: Research Article
ISSN: 0332-1649

Article
Publication date: 27 June 2008

Dang Huu Chung and Dieter P. Eppel

The aim is to investigate in detail the sensitivity of sediment transport and bed morphology with respect to some parameters including bed slope, non‐hydrostatic pressure term…

Abstract

Purpose

The aim is to investigate in detail the sensitivity of sediment transport and bed morphology with respect to some parameters including bed slope, non‐hydrostatic pressure term, sand grain size, temperature, salinity and lower boundary conditions for suspended sand concentration on a regional scale through numerical simulations based on a mathematical model.

Design/methodology/approach

The numerical model consists of a 3D hydrodynamic code amended by a sediment transport module. At the same time, the influence of wave action has been taken into account. The model is applied to the Sylt‐Romo tidal bay covering approximately 20 × 30 km2 spanned by about 2.7 × 106 active grid points with the constant wind and wave fields.

Findings

The computed results of seven different cases over 150 h show that the effect of bed slope correction is very strong, especially in case of largely changeable bathymetry and depends on the horizontal grid resolution. Sand grain size strongly influences the vertical distribution of suspended sediment and then sedimentation. The impact of sea water temperature is relatively clear despite being less powerful than two former parameters. Non‐hydrostatic pressure perturbations of the flow field and the kind of the lower boundary condition as well as salinity are negligible allowing for considerable savings of CPU time when the numerical simulation is carried out for a large area and for a very long‐time period.

Originality/value

The results of the study demonstrate that the geometrical factor of coastal bed and the range of sand particle size on the bottom contribute to the tendency of bed evolution in some measure. Additionally, the increase of temperature of sea water due to global warming may also make a considerable change to the mechanism of sediment transport and sedimentation in future. Therefore, the human intervention in the process of natural evolution is possible through the behaviour to the nature. At the same time, this is also interesting and useful information and it can consolidate the idea for coastal engineering projects.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 18 no. 5
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 1 January 1993

A. MAJORANA and G. RUSSO

Two hydrodynamic models of a semiconductor device are considered. The first takes into account thermal and collisional effects, while neglecting viscous terms, which are included…

Abstract

Two hydrodynamic models of a semiconductor device are considered. The first takes into account thermal and collisional effects, while neglecting viscous terms, which are included in the second. A qualitative analysis of stationary one‐dimensional solutions is performed and a numerical comparison is presented.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 12 no. 1
Type: Research Article
ISSN: 0332-1649

1 – 10 of 109