Department of Mechanical Engineering
Kenneth E. Goodson
Marconnet, A.M., Asheghi, M., and Goodson, K.E., 2013, "From the Casimir Limit to Phononic Crystals: Twenty Years of Phonon Transport Studies using Silicon-on-Insulator Technology," Journal of Heat Transfer, Vol. 135, 061601 (Heat Transfer Divison Anniversary Issue).
Silicon-on-insulator (SOI) technology has sparked advances in semiconductor and
MEMs manufacturing and revolutionized our ability to study phonon transport phenomena
by providing single-crystal silicon layers with thickness down to a few tens of nanometers.
These nearly perfect crystalline silicon layers are an ideal platform for studying
ballistic phonon transport and the coupling of boundary scattering with other mechanisms,
including impurities and periodic pores. Early studies showed clear evidence of
the size effect on thermal conduction due to phonon boundary scattering in films down to
20 nm thick and provided the first compelling evidence for the Casimir limit at room temperature. More recent studies on ultrathin films and periodically porous
thin films are exploring the possibility of phonon dispersion modifications in confined
geometries and porous films.