Multiscale thermal transport.

Graham, Samuel, Jr. ; Wong, C. C. ; Piekos, Edward Stanley

Sandia National Laboratories

关键词: Transport Microelectromechanical Systems.;    Thermal Conductivity;    Phonons;    Materials-Thermal Properties.;    Acoustics;   

DOI  :  10.2172/889417
RP-ID  :  SAND2004-0531
RP-ID  :  AC04-94AL85000
RP-ID  :  889417

美国|英语

来源: UNT Digital Library

【 摘 要 】

A concurrent computational and experimental investigation of thermal transport is performed with the goal of improving understanding of, and predictive capability for, thermal transport in microdevices. The computational component involves Monte Carlo simulation of phonon transport. In these simulations, all acoustic modes are included and their properties are drawn from a realistic dispersion relation. Phonon-phonon and phonon-boundary scattering events are treated independently. A new set of phonon-phonon scattering coefficients are proposed that reflect the elimination of assumptions present in earlier analytical work from the simulation. The experimental component involves steady-state measurement of thermal conductivity on silicon films as thin as 340nm at a range of temperatures. Agreement between the experiment and simulation on single-crystal silicon thin films is excellent, Agreement for polycrystalline films is promising, but significant work remains to be done before predictions can be made confidently. Knowledge gained from these efforts was used to construct improved semiclassical models with the goal of representing microscale effects in existing macroscale codes in a computationally efficient manner.