A measurement method of thermal conductivities of Cu thin films was devised from the temperature distributions of substrate surfaces. The substrate was prepared to have a prismatic bar shape, and was deposited with Cu thin films using sputtering. Two metal coated surfaces of specimens were brought into contact to maintain the insulated boundary condition. Specimens were heated with constant temperature at both ends. The temperature distributions were measured from the back surface of substrate using a radiation thermometry.
The thermal conductivities of Cu thin films were found to be much lower than those of bulk materials. Wiedemann-Franz law could be applied to thin films produced in this study. Thermal conductivity was also estimated from the resistivity of thin film and Lorenz number of bulk material.