Thermal insulating layer on a conducting substrate. Analysis of thermoreflectance experiments
Résumé
Thermoreflectance experiments are sensitive to the thermal properties of thin layers deposited on substrates (conductivity and diffusivity). However, retrieving these properties from experimental data remains a difficult issue. The case of a conducting layer deposited on an insulating substrate was studied previously. We present here a mathematical and experimental analysis of the thermoreflectance response in the opposite case: an insulating layer on a conducting substrate. We show theoretically that conductivity and diffusivity can be determined independently thanks to a comparison with the substrate. The method is applied to experiments performed on a silicon substrate covered with a thin layer deposited by sputtering a titanium target. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.3702823]