Ultra-thin Dielectric Film Of Thermal Diffusivity Test

With the decrease of the thin film抯 thickness, its thermal properties will be different from its volumetric materials and exhibit microscale properties. The paper, based on the experiments, uses AC calorimetric method to make research on thin film抯 thermal diffusivity of Si07 Si3N4 and poly- Si. The paper introduces briefly the concept of the heat transfer, microscale criterion and the challenge of the microscale to the macroscale theories; and includes microscale models, such as two- step model, phonon radiative transfer model, phonon-scattering model, thermal wave model; and then gives the measuring methods of the diffusivity of thin films, which includes the principle of AC calorimetric method, the design of the samples, the experimental setup, and the working principle; at last, it ends with the disposal of experimental data and the analysis of experimental results. The thermal diffusivity of the microscale thin films is smaller than their corresponding volumetric materials, and with the decrease of the thickness of thin films, they become smaller. This is proved in the paper and gets qualitative explanation.