Method for determining the lubrication mechanism of post-ILD CMP brush scrubbing

摘要

A method using spectral analysis of friction data is established to determine the tribological mechanism of post-interlevel dielectric (post-ILD) chemical mechanical planarization (CMP) brush scrubbing as a function of solution pH, pressure, and tool kinematics. Spectral analysis based on real-time raw friction data is used to quantify the total amount of mechanical interaction in the brush-fluid-wafer interface in terms of stick-slip phenomena. Friction force variance (sigma(2)) criterion is established to determine the tribological mechanism during scrubbing, and compared to the classical method by constructing and interpreting Stribeck curves.