Investigation of eccentric PVA brush behaviors in post-Cu CMP cleaning

Behavior of an eccentric PVA brush is investigated during post-Cu chemical mechanical planarization (CMP) brush cleaning. It is observed that the measured contact pressure and contact area of the eccentric brush vary significantly under different brush orientations. Moreover, the eccentric brush behaves differently from the good (i.e. concentric) brush in both the variance of shear force as well as the force spectra during cleaning. This study provides a rapid detection method to screen out eccentric brushes before they are used in semiconductor manufacturing, thereby potentially reducing wafer defects as well as chemical, water, and energy consumption associated with using eccentric PVA brushes.