First-principles calculations of thermal transport at metal/silicon interfaces: Evidence of interfacial electron-phonon coupling

Thermal transport at metal/semiconductor interfaces is important for management of microelectronic devices. At these interfaces, heat transfer is generally described in terms of phonon transmission and a coupling between metal's electrons and phonons in the semiconductor is believed to have a negligible impact. Here, the authors show that the interface electron-phonon coupling may amount to one third of the total thermal boundary conductance. First-principle calculations reveal that the controlling parameter is the metal's Debye frequency, and high Debye frequency favors electron-phonon coupling at the interface.