Nanoindentation based method to determine the thermal expansion coefficients of low-k dielectrics

Abstract

This paper demonstrates the use of nanoindentation at elevated temperatures to measure the coefficient of thermal expansion (CTE) of low-k dielectric films. This methodology was calibrated using curvature measurements to elucidate the impact of tip geometry and elastic modulus on the theoretical model to calculate the CTE. Further validation was achieved by applying this methodology on a variety of low-k dielectric films with different elastic modulus, but similar matrix density. The advantage of this methodology over other techniques is the capability to simultaneously measure the elastic modulus, the easy sample preparation, short measurement time and easy analysis.