Pad conditioning restores degraded pad surfaces after wafer polishing in chemical mechanical planarization (CMP) using diamond-embedded conditioner discs. However, conditioning also causes pad cutting, thickness reduction, and profile deformation. While previous studies mainly focused on reducing pad cut rate (PCR) and improving profile uniformity, the fundamental cutting mechanism between conditioner cutting edges and the pad remains unclear. This study investigates the cutting mechanism using CVD conditioner discs with different cutting edge densities under varying conditioning loads to control contact area and load distribution. PCR and pad profile analyses revealed that cutting behavior is primarily governed by the load applied to individual cutting edges. Higher localized loads increased the contribution of cutting to overall material removal. In the pad edge region, where the conditioner partially overhangs the pad, altered contact geometry caused a transition in cutting mode. In this region, the number of active cutting edges had a greater influence than the load per edge. These findings clarify the cutting interactions between CVD conditioner edges and pad surfaces during conditioning and provide a physical foundation for optimizing conditioning parameters to improve pad management in CMP processes.
Chemical Mechanical Polishing (CMP) is a crucial process in advanced semiconductor manufacturing, essential for achieving global planarization of the wafer surface, which directly impacts device performance and yield. Uniform material removal across the wafer is vital; however, non-uniformity frequently occurs, even with nominally uniform applied pressure. A prevalent issue is the edge effect, where the removal rate at the wafer edge significantly differs from that at the center, resulting in reduced uniformity and compromised device reliability. To tackle this challenge, this study explores the effectiveness of a multi-zone pressure-controlled carrier in enhancing polishing uniformity. Conventional single-zone carriers can only influence a narrow region of approximately 5–7 mm at the wafer edge, leading to limited improvements in nonuniformity of about 3%. In contrast, the multi-zone carrier allows for precise pressure control over a broader range, extending from 3 mm to 20 mm from the wafer edge. Experimental results show that this approach reduces non-uniformity to below 3% while effectively addressing edge removal deficiencies. These findings underscore the significant potential of multi-zone carriers to improve CMP process precision. Consequently, the proposed method is anticipated to enhance both productivity and quality in semiconductor fabrication.
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