Description:
<jats:p> This work demonstrates the performance of a microreplicated pad used in a W buff polish process. 3M™ Trizact™ microreplicated pads consist of matrix designed asperitity and pore structures that can be tuned independently, into a wide variety of complex 3D structures. More uniform pad asperity diameter and height control allows for better wafer-pad contact interacions. Consequently, microreplicated pads have significantly higher contact area with the wafer surface compared to industry standard hard and soft pads. The unique heringbone groove design allows for efficient slurry transportation and uniform slurry flow distribution – enabling the potential for slurry saving and cost of ownership reduction. </jats:p>
<jats:p>The CMP wafer polish results show stable oxide RR (se Figure 1) and consistent W:Ox film selectivity over 3000 wafers. Wafer removal rate recovey was repeatablly fast following periods of wet idle. Stable uniformity/edge profile control were also achieved. Total defect counts were controlled and consistent throughout the duration of the 3000 wafer marathon run. Upon completion of the marathon run, the loss in pad asperity height loss was less than 3 microns (14 %) compared to initial asperity height illustrating the potential to extend the pad life significantly beyond 3000 wafers (see Figure 2). The results illustrate the benefit of micro-replicated asperities in CMP pads, These results are important because of the potential to improve pad performance and reduce the cost of CMP.</jats:p>
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<jats:p>Figure 1</jats:p>
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