Simultaneous Measurement of Cross-Plane Thermal Conductivity and Interfacial Thermal Conductance of Nano-Metal Films on a Low Thermal Diffusivity Substrate Using TDTR

The thermal transport properties are very significant for the performance, reliability, and service life of nano-electronic devices. However, effectively measuring the thermal transport properties of nano-metal films is a challenge job, especially for the interfacial thermal conductance between nano-metal films and substrate with low thermal diffusivity. In this study, we improve the traditional time-domain thermoreflectance (TDTR) technique to simultaneously measure cross-plane thermal conductivity and interface thermal conductance of film/substrate assembly with an improved measurement sensitivity. By capturing the reflected beams from the film side and substrate side, and fitting the captured signals with thermal transport models, we simultaneously measure the cross-plane thermal conductivity of Al film, Cr film and SiO2 substrate, as well as the interfacial thermal conductance of Al/Cr and Cr/SiO2 interfaces. The experimental results show that the interfacial thermal conductance of Al/Cr interface is much larger than that of Cr/SiO2 interface, and the cross-plane thermal conductivity of Al film and Cr film is much smaller than their corresponding bulk value. Furthermore, we use the Monte Carlo method to analyze the uncertainty of measured parameters and obtain the corresponding error range.