AVS 51st International Symposium
    Materials Solutions for Cooling Technology Topical Conference Monday Sessions
       Session CT+TF-MoM

Paper CT+TF-MoM1
Impact of Electron-Phonon Coupling on Thermal Boundary Resistance by Molecular-Dynamics Simulation

Monday, November 15, 2004, 8:20 am, Room 303B

Session: Thermal Transport in Thin Films and Nanostructured Materials
Presenter: R.J. Stevens, University of Virginia
Authors: R.J. Stevens, University of Virginia
P.M. Norris, University of Virginia
Correspondent: Click to Email
With the growing interest in ULSI circuits and superlattices, an increasing need to understand thermal transport mechanisms across interfaces has become necessary. As the density of interfaces rapidly increases, device level thermal management is no longer dominated by the thermal properties of the individual layers but rather the thermal boundary resistances (TBR). Unfortunately, our current understanding of room temperature TBR is not adequate for proper thermal design of interface dense devices. Most TBR theoretical work has been an extension of the acoustic mismatch theories and has been limited to phonon elastic scattering processes for perfect interfaces. Other transport mechanisms have been considered such as electron-phonon (e-p) scattering and inelastic phonon scattering. There has been very little effort to systematically measure room temperature TBR and verify the proposed theories. Unfortunately, measuring TBR is quite difficult, although there has been some success using ultrafast spectroscopy techniques. Alas, it is problematical to systematically fabricate and fully characterize a series of interfaces and validate the proposed models. Molecular-dynamics simulations (MDS) can enhance existing experimental work by allowing analysis of controlled and well-defined interfaces. MDS enable the ability to alter material properties and atomic-level structure of the interface, so the mechanisms of TBR can better be understood. In this work, we perform MDS of the energy transport through an interface of a Si â?" metal system described by semi-empirical potentials (Stillinger-Weber and Embedded Atom Method). The electronic heat conduction in the metal film and e-p coupling are included by using a recently developed model that combines MD with a continuum description of the evolution of the electron temperature. The electron scattering contribution to TBR is determined by altering the e-p coupling strength in the bulk and at the interface.