Measurement of thermal conductivity of silicon dioxide thin films using a 3ω method

The thermal conductivity of SiO2 thin films prepared using various procedures has been studied using a 3ω method. The thermal conductivity of SiO2 thin films of above approximately 500 nm thickness decreases as the porosity of the specimen, which is determined by infrared absorption spectroscopy, increases. Below approximately 250 nm thickness, the observed thermal conductivity of the SiO2 thin films systematically decreases as a function of film thickness. The data have been analyzed based on a SiO2-thickness-independent thermal conductivity and interfacial resistance. The total estimated interfacial resistance between the metal strip and the film, and between the film and the substrate is about 2×10−8 m2 KW−1.