A Rapid Method to Measure Thermal Conductivity of Dielectric Thin Films: Thermal Resistance Method

A new and relatively simple method, described for thermal conductivity measurement of dielectric thin films, is presented in this paper. This new technique, the thermal resistance method, can be applied to determine cross-plane thermal conductivity of thin film by electrical heating and sensing techniques without traditional free standing structure design. A slender metal line, deposited on top of dielectric film, is used to measure and extract thermal resistance (R_c) of composite structure, including substrate and dielectric film. A 2-D analytical solution is derived to get thermal resistance (R_s) of substrate. Therefore, the thermal resistance of thin film (R_f) is calculated by subtracting R_s form R_c and thermal conductivity of thin film can also be extracted from thermal resistance. The measurement data of silicon dioxide with difference thickness are verified by using previous scientific literatures. In addition, the measuring results also show good agreement with those measured by 3 omega method. According to advantages of rather rapid and accuracy, this new technique has potential to develop to be an in-line test key for MEMS and IC relative industries.