Early resistance change and stress/electromigrationmodeling in aluminium interconnects

A complete description for early resistance change and two dimensional simulation of mechanical stress evolution in confined Al interconnects, related to the electromigration, is given in this paper. The model, combines the stress/ vacancy concentration evolution with the early resistance change of the Al line, that could be [1] a fast technique for prediction of the MTF of a line compared to the conventional (accelerated) tests

A new tightly-coupled transient electro-thermal simulation method for power electronics

Paper no. 224This paper presents a new transient electro-thermal (ET) simulation method for fast 3D chip-level analysis of power electronics with field solver accuracy. The metallization stacks are meshed and solved with 3D field solver using nonlinear temperature-dependent parameters, and the active devices are modeled with nonlinear tabular compact models to avoid time-consuming TCAD simulation. The main contributions include: 1) A tightly-coupled formulation that solves the electrical and thermal responses simultaneously for better convergence property; 2) Explicit account of capacitive effects, including interconnect parasitic capacitance and gate capacitance of power devices, to improve modeling accuracy in highfrequency applications; 3) A specialized transient solver based on the matrix exponential method (MEXP) to address the multi-scale problem caused by the considerably different time scales in electrical and thermal dynamics. Numerical experiments have demonstrated the advantages of the proposed co-simulation framework.postprin

Computation of Self-Induced Magnetic Field Effects Including the Lorentz Force for Fast-Transient Phenomena in Integrated-Circuit Devices

We present a full physical simulation picture of the electromagnetic phenomena combining electromagnetic (EM) fields and carrier transport in semiconductor devices (TCAD) in the transient regime. The simulation tool computes the EM fields in a self-consistent way and the resulting magnetic fields are incorporated in the computation of the current sources that get modified by the Lorentz force (LF).published_or_final_versio

Simulation of large interconnect structures using ILU-type preconditioner

For a fast simulation of interconnect structures we consider preconditioned iterative solution methods for large complex valued linear systems. In many applications the discretized equations result in ill-conditioned matrices, and efficient preconditioners are indispensable to solve the linear systems accurately. We apply the dual threshold incomplete LU (ILUT) factorization as preconditioners for the BICGSTAB iterative solver. On complicated problems with a different range of frequencies we show that the BICGSTAB method with the ILUT preconditioner provides a very accurate solution of the linear systems

An effective formulation of coupled electromagnetic-TCAD simulation for extremely high frequency onward

This paper presents an effective formulation tailored for electromagnetic-technology computer-aided design coupled simulations for extremely-high-frequency ranges and beyond (> 50 GHz). A transformation of variables is exploited from the starting A-V formulation to the E-V formulation, combined with adopting the gauge condition as the equation for scalar potential. The transformation significantly reduces the cross-coupling between electric and magnetic systems at high frequencies, providing therefore much better convergence for iterative solution. The validation of such transformations is ensured through a careful analysis of redundancy in the coupled system and material properties. Employment of the advanced matrix permutation technique further alleviates the extra computational cost introduced by the variable transformation. Numerical experiments confirm the accuracy and efficiency of the proposed E-V formulation. © 2011 IEEE.published_or_final_versio

A fast time-domain EM-TCAD coupled simulation framework via matrix exponential

We present a fast time-domain multiphysics simulation framework that combines full-wave electromagnetism (EM) and carrier transport in semiconductor devices (TCAD). The proposed framework features a division of linear and nonlinear components in the EM-TCAD coupled system. The former is extracted and handled independently with high efficiency by a matrix exponential approach assisted with Krylov subspace method. The latter is treated by ordinary Newton's method yet with a much sparser Jacobian matrix that leads to substantial speedup in solving the linear system of equations. More convenient error management and adaptive control are also available through the linear and nonlinear decoupling. © 2012 ACM.published_or_final_versio

Quantum Transport in a Nanosize Silicon-on-Insulator Metal-Oxide-Semiconductor

An approach is developed for the determination of the current flowing through a nanosize silicon-on-insulator (SOI) metal-oxide-semiconductor field-effect transistors (MOSFET). The quantum mechanical features of the electron transport are extracted from the numerical solution of the quantum Liouville equation in the Wigner function representation. Accounting for electron scattering due to ionized impurities, acoustic phonons and surface roughness at the Si/SiO2 interface, device characteristics are obtained as a function of a channel length. From the Wigner function distributions, the coexistence of the diffusive and the ballistic transport naturally emerges. It is shown that the scattering mechanisms tend to reduce the ballistic component of the transport. The ballistic component increases with decreasing the channel length.Comment: 21 pages, 8 figures, E-mail addresses: [email protected]

O parlamento no ecrã: debate e conversação na televisão contemporânea

A televisão contemporânea caracteriza-se pelo grandíssimo destaque concedido às interacções discursivas. Com efeito, a saliência dos talk-shows e a programas de comentário, bem como rubricas de eminente partilha de opiniões em programas de outros géneros televisivos, confirmam esta incidência conversacional da televisão. Analisando o modo como uma discussão pública da experiência social ocorre, este artigo investiga o parlamento televisivo, isto é, essa tendência generalizada de discursivização ao mesmo tempo que sublinha as mutações positivas que ela impôs às audiências televisivas. Deste modo, e contrariamente à perspectiva convencional disfórica (audiências tendencialmente passivas, desinteressadas e apáticas), esboçar-se-á uma compreensão renovada das audiências televisivas que as coloca como participantes activas deste parlamento no ecrã. Com este objectivo, far-se-á uma breve caracterização do parlamento televisivo, descrever-se-á os seus fundamentos, e distinguir-se-ão os seus modos performativos.Parley on Screen – debate and conversation in contemporary television The contemporary television is characterized by the prominence accorded to discussion. Indeed, talk-shows and chatting programs successes, confirm this prevalence of a conversational dimension on television. Analyzing the way public discussion of social experience happens, this paper investigates the televised parley, i.e. this stress in conversation and dialogue, and, at the same time, underscores the positive change that it has imposed on television audiences. Thus, contrary to the conventional dysphoric perspective (audiences seen as passive, disinterested and apathetic), the paper sketches a renewed understanding of the television audience that put them as active participants on the parley television. With this objective, a brief characterization of the televised parley, its principles and performance modes, will be made.info:eu-repo/semantics/publishedVersio

Nonperturbative confinement in quantum chromodynamics:III. Improved gluon propagator

An ansatz is introduced for the three‐gluon vertex that is consistent with the Slavnov–Taylor identity in Landau gauge. It is shown that the gluon has a confining infrared singularity; but there is also a tachyon, indicating an insufficiency either of quarkless QCD or at least of our approximation to it