Effect of spray nozzle position on pad temperature distribution and wafer non-uniformity

During chemical mechanical planarization (CMP), the pad surface temperature generally increases due to the friction between the wafer and the pad. A pad with a large sliding distance generates more heat compared to pad with small sliding distance. A nonuniform temperature distribution on the pad causes its mechanical properties to become uneven, which are affected by within-wafer non-uniformity (WIWNU). This study aims to improve the polishing uniformity by controlling the temperature profile of the pad surface for each spray nozzle position. When the slurry was sprayed on an area for which a large slide distance was measured, a uniform temperature distribution and improved WIWNU were obtained.