Thickness dependency and interfacial structure effects on thermal properties of AlN thin films were systematically investigated by characterizing cross-plane and in-plane thermal conductivities, crystal structures, chemical compositions, surface morphologies and interfacial structures using an extended differential 3ω method, X-ray diffraction (XRD) analysis, X-ray photoelectron spectroscopy, atomic force microscopy (AFM) and transmission electron microscopy. AlN thin films with various thicknesses from 100 to 1000 nm were deposited on p-type doped silicon substrates using a radio frequency reactive magnetron sputtering process. Results revealed that both the cross- and in-plane thermal conductivities of the AlN thin films were significantly smaller than those of the AlN in a bulk form. The thermal conductivities of the AlN thin films were strongly dependent on the film thickness, in both the cross- and in-plane directions. Both the XRD and AFM results indicated that the grain size significantly affected the thermal conductivity of the films due to the scattering effects from the grain boundary.
Bogner, M., Benstetter, G., & Fu, Y. Q. (2017, June 25). Cross- and in-plane thermal conductivity of AlN thin films measured using differential 3-omega method. Surface and Coatings Technology. Elsevier B.V. https://doi.org/10.1016/j.surfcoat.2017.01.100