A study on the thermal conductivity measurements of Cu thin films utilizing temperature distribution

Thin film type materials are widely used in high-tech industries including electronics, photonics and even machine tools. Often, knowledge of the thermal properties of thin films is needed to assess reliability through thermal stress analysis when the thin film type materials are applied to functional electronic parts. Only a few methods have been developed for thermal conductivity measurement of a thin film on a substrate. In this study Cu thin films were processed on the borosilicate glass substrate of prismatic bar shape using sputtering. Two Cu coated surfaces of specimens were brought into contact to maintain the insulated boundary conditions. The temperature distributions were measured from the back surface of the substrate using radiation thermometry. The thermal conductivities of the Cu thin films were measured and found to be much lower than those of bulk materials. The measured thermal conductivities were found to be closely related to the microstructures of the Cu thin films.