Determination of thermal parameters of thin film materials by thermoreflectance profile analysis and multiparameter 3D model fitting

In this work, we propose a 3D model which allows us to determine the thermal parameters (thermal diffusivity and thermal conductivity) of a thin layer deposited on a substrate, from the analysis of the amplitude and the phase of the photothermal signal. In addition, the validity of our model is confirmed by comparing it to a procedure, well described in the literature [9] and based on the asymptotic behavior of the heat diffusion, that extract separately the thermal diffusivity and conductivity of the thin conductive layer deposited on an insulator, where the thickness of the thin layer and the thermal properties of the substrate are known. We also present different simulations that illustrate the use of this technique for the thermal characterization of thin films and the application of our developed model in order to fit the data and obtain the required thermal properties.In this work, we propose a 3D model which allows us to determine the thermal parameters (thermal diffusivity and thermal conductivity) of a thin layer deposited on a substrate, from the analysis of the amplitude and the phase of the photothermal signal. In addition, the validity of our model is confirmed by comparing it to a procedure, well described in the literature [9] and based on the asymptotic behavior of the heat diffusion, that extract separately the thermal diffusivity and conductivity of the thin conductive layer deposited on an insulator, where the thickness of the thin layer and the thermal properties of the substrate are known. We also present different simulations that illustrate the use of this technique for the thermal characterization of thin films and the application of our developed model in order to fit the data and obtain the required thermal properties.