A Technique for Deducing In-Plane Modulus and Coefficient of Thermal Expansion of a Supported Thin Film

Abstract

A technique for determining the in-plane modulus and the coefficient of thermal expansion (CTE) of supported thin films has been developed. The modulus and CTE are calculated by solving two coupled equations that relate the curvature of film samples deposited on two different substrates to the thermal and mechanical properties of the constituents. In contrast with the conventional method used to calculate modulus and CTE, which involves differentiation of the thermal stress in the film, this new technique does not require the differentiation of the thermal stress, and can also provide the temperature-dependence of the in-plane CTE and elastic modulus of supported thin films. The data reduction scheme used for deducing CTE and elastic modulus is direct and reliable.