Effects of Ring Design on CMP Process Stability and Slurry Usage

Slurry Reduced with Optimized <strong>Ring</strong>Standard Slot <strong>Design</strong>Alternate Slot <strong>Design</strong>Slurry Film Thickness ( m)Slurry Film Thickness ( m)12.010.08.06.04.02.00.012.010.08.06.04.02.080 RPM 1.8 PSI220 cc/min80 RPM 1.8 PSI150 cc/min80 RPM 3.6 PSI220 cc/minRegion ARegion B80 RPM 3.6 PSI150 cc/minRegion ARegion BSlurry Film Thickness ( m)Slurry Film Thickness ( m)12.010.08.06.04.02.00.012.010.08.06.04.02.0120 RPM 1.8 PSI220 cc/min120 RPM 1.8 PSI150 cc/min120 RPM 3.6 PSI220 cc/minRegion ARegion B120 RPM 3.6 PSI150 cc/minRegion ARegion BSlurry FilmThickness VaryingProcess Parameters0.080 RPM 1.8 PSI220 cc/min80 RPM 1.8 PSI150 cc/min80 RPM 3.6 PSI220 cc/min80 RPM 3.6 PSI150 cc/min0.0120 RPM 1.8 PSI220 cc/min120 RPM 1.8 PSI150 cc/min120 RPM 3.6 PSI220 cc/min120 RPM 3.6 PSI150 cc/min Alternate ring design achieved 39% greater slurry film thicknesscompared to an industry standard design ring Normalizing on slurry film thickness for both ring designs, slurryusage would be reduced 28% with an optimized ring slot design. Slurry film thickness in the pad/wafer interface region is greater asone moves away from the inner edge (Region A) <strong>of</strong> the ringPage 7ENTEGRIS PROPRIETARY AND CONFIDENTIAL, Published only with Permission