Thermal Conductivity and Thermal Interface Resistance Measurements of Thin Films using 3ω Method

摘要

A large number of experimental and theoretical studies investigating thermal conductivity of both bulk and thin films exist in the literature. For measurement of thermal conductivity of bulk films we have methods like Guarded Hot Plate method, Flash method and for thin films we have methods like Thermo reflectance and Photo acoustic methods. What makes 3ω method different from other methods is that it can be used over a wide range of film thicknesses ranging from nano scale to milli meters. The purpose of the present study is to validate the method and measure thermal conductivity and thermal interface resistance of thin films of varying thickness. In the present study, we have measured thermal conductivity of thin films of SiO_2 of varying thickness deposited on Si substrate and thermal interface resistance of their interfaces. Initially all the required thin films of different thickness were fabricated using different techniques. Firstly, experiments were conducted on a bulk borofloat glass to validate the method, followed by the measurements for thin films. The results are in close accordance with the previous research. The thermal conductivity of borofloat glass was measured to be 1.16 W/mK with a 5.2% deviation from the actual value. In the last section possible sources of error in the final measurements are discussed.