scholarly journals Heat Transport Driven by the Coupling of Polaritons and Phonons in a Polar Nanowire

Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 5110
Author(s):  
Yangyu Guo ◽  
Masahiro Nomura ◽  
Sebastian Volz ◽  
Jose Ordonez-Miranda
Keyword(s):  
Heat Transport ◽  
State Of The Art ◽  
Boltzmann Transport Equation ◽  
Thermal Conductance ◽  
Heat Diffusion ◽  
Heat Sources ◽  
Boltzmann Transport ◽  
Heat Diffusion Equation ◽  
Current State ◽  
Linear Behavior

Heat transport guided by the combined dynamics of surface phonon-polaritons (SPhPs) and phonons propagating in a polar nanowire is theoretically modeled and analyzed. This is achieved by solving numerically and analytically the Boltzmann transport equation for SPhPs and the Fourier’s heat diffusion equation for phonons. An explicit expression for the SPhP thermal conductance is derived and its predictions are found to be in excellent agreement with its numerical counterparts obtained for a SiN nanowire at different lengths and temperatures. It is shown that the SPhP heat transport is characterized by two fingerprints: (i) The characteristic quantum of SPhP thermal conductance independent of the material properties. This quantization appears in SiN nanowires shorter than 1 μm supporting the ballistic propagation of SPhPs. (ii) The deviation of the temperature profile from its typical linear behavior predicted by the Fourier’s law in absence of heat sources. For a 150 μm-long SiN nanowire maintaining a quasi-ballistic SPhP propagation, this deviation can be as large as 1 K, which is measurable by the current state-of-the-art infrared thermometers.

Modeling of Localized Heating Effect in Sub-Micron Silicon Transistors

2003 ◽  
Author(s):  
Keivan Etessam-Yazdani ◽  
Sadegh M. Sadeghipour ◽  
Mehdi Asheghi
Keyword(s):  
Transport Equation ◽  
Hot Spot ◽  
Boltzmann Transport Equation ◽  
Phonon Transport ◽  
Heat Diffusion ◽  
Normal Operation ◽  
Heating Effect ◽  
Boltzmann Transport ◽  
Heat Diffusion Equation ◽  
Localized Heating

The performance and reliability of sub-micron semiconductor transistors demands accurate modeling of electron and phonon transport at nanoscales. The continued downscaling of the critical dimensions, introduces hotspots, inside transistors, with dimensions much smaller than phonon mean free path. This phenomenon, known as localized heating effect, results in a relatively high temperature at the hotspot that cannot be predicted using heat diffusion equation. While the contribution of the localized heating effect to the total device thermal resistance is significant during the normal operation of transistors, it has even greater implications for the thermoelectrical behavior of the device during an electrostatic discharge (ESD) event. The Boltzmann transport equation (BTE) can be used to capture the ballistic phonon transport in the vicinity of a hot spot but many of the existing solutions are limited to the one-dimensional and simple geometry configurations. We report our initial progress in solving the two dimensional Boltzmann transport equation for a hot spot in an infinite media (silicon) with constant temperature boundary condition and uniform heat generation configuration.

Study of an Iterative Solution for Boltzmann Transport Equation and Calculation of Thermal Conductivity

2018 ◽  
Vol 777 ◽  
pp. 421-425 ◽  
Author(s):  
Chhengrot Sion ◽  
Chung Hao Hsu
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Numerical Calculation ◽  
Iterative Method ◽  
Transport Equation ◽  
Linear Systems ◽  
Heat Transport ◽  
Boltzmann Transport Equation ◽  
Iterative Solution ◽  
Boltzmann Transport

Many methods have been developed to predict the thermal conductivity of the material. Heat transport is complex and it contains many unknown variables, which makes the thermal conductivity hard to define. The iterative solution of Boltzmann transport equation (BTE) can make the numerical calculation and the nanoscale study of heat transfer possible. Here, we review how to apply the iterative method to solve BTE and many linear systems. This method can compute a sequence of progressively accurate iteration to approximate the solution of BTE.

Sub-Continuum Simulations of Heat Conduction in Silicon-on-Insulator Transistors

1999 ◽  
Author(s):  
Per G. Sverdrup ◽  
Y. Sungtaek Ju ◽  
Kenneth E. Goodson
Keyword(s):  
Diffusion Equation ◽  
Free Path ◽  
Temperature Rise ◽  
Mean Free Path ◽  
Channel Length ◽  
Silicon On Insulator ◽  
Heat Diffusion ◽  
Boltzmann Transport ◽  
Heat Diffusion Equation ◽  
Silicon Devices

Abstract The temperature rise in compact silicon devices is predicted at present by solving the heat diffusion equation based on Fourier’s law. The validity of this approach needs to be carefully examined for semiconductor devices in which the region of strongest electronphonon coupling is narrower than the phonon mean free path, Λ, and for devices in which Λ is comparable to or exceeds the dimensions of the device. Previous research estimated the effective phonon mean free path in silicon near room temperature to be near 300 nm, which is already comparable with the minimum feature size of current generation transistors. This work numerically integrates the phonon Boltzmann transport equation (BTE) within a two-dimensional Silicon-on-Insulator (SOI) transistor. The BTE is coupled with the classical heat diffusion equation, which is solved in the silicon dioxide layer beneath a transistor with a channel length of 400 nm. The sub-continuum simulations yield a peak temperature rise that is 159 percent larger than predictions using only the classical heat diffusion equation. This work will facilitate the development of simpler calculation strategies, which are appropriate for commercial device simulators.

Dissipative Behaviour of Metallic Materials in Low Stress Cyclic Loading

2006 ◽  
Vol 3-4 ◽  
pp. 253-258
Author(s):  
Francois Maquin ◽  
Fabrice Pierron
Keyword(s):  
High Cycle Fatigue ◽  
Temporal Integration ◽  
Heat Diffusion ◽  
Temperature Fields ◽  
Heat Sources ◽  
Metallic Materials ◽  
Heat Diffusion Equation ◽  
Spatio Temporal ◽  
Metallic Specimen ◽  
Thermal Sources

In order to fully understand the thermomechanical phenomena involved in high-cycle fatigue, a method for determining the dissipative thermal sources in a loaded metallic specimen from the spatio-temporal integration of the heat diffusion equation is proposed. Temperature fields obtained through a focal array infra-red camera are processed with this technique. After a refined analysis of the sensitivity of the method, preliminary tests have shown that it is possible to detect a burst of heat sources within the first couple of cycles for the specimen tested above a certain level of tensile stress. This behaviour is thought to be related to the microplasticity level.

Simulations of Heat Transport During Transient Electrostatic Discharge Events in a Sub-Micron Transistor

Volume 4 ◽  
2004 ◽  
Author(s):  
Sreekant V. J. Narumanchi ◽  
Jayathi Y. Murthy ◽  
Cristina H. Amon
Keyword(s):  
Transport Equation ◽  
Heat Transport ◽  
Electrostatic Discharge ◽  
Boltzmann Transport Equation ◽  
The Other ◽  
Comprehensive Model ◽  
Boltzmann Transport ◽  
Thermal Problem ◽  
Model Based ◽  
Silicon Transistors

The thermal problem associated with the transient electrostatic discharge phenomena in sub-micron silicon transistors is fast becoming a major reliability concern in IC packages. Currently, Fourier diffusion and some simple models based on the solution to the phonon Boltzmann transport equation (BTE) are used to predict failure (melting of silicon) in these transistors. In this study, a more comprehensive model, based on the phonon BTE and incorporating considerable details of phonon physics, is proposed and used to study the ESD problem. Transient results from the model reveal very significant discrepancies when compared to results from the other models in the literature.

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