The wafer level impact of different IC1000 pad imperfections were screened and evaluated. The defect classifications were based on visual inspection and segregation of pads used during a 3 month period under a high-volume manufacturing environment. The screening tests revealed that the defects must be embedded into or onto the pad to cause a negative impact on wafer-level defects. Among these defects, the most abundant mode, namely, the voids, was characterized in further detail for wafer-level impact. It was shown that voids as small as 0.5 mm diam (which pass the current manufacturer specifications) show statistically significant increase in wafer level defects. A mechanism was proposed for the defect formation due to these voids acting as slurry agglomeration centers. (c) 2006 The Electrochemical Society.