Published online by Cambridge University Press: 31 January 2011
Material removal during CMP occurs by the activation of slurry particles at contact points between pad summits and the wafer. When slurry is present and the wafer is sliding, contacts become lubricated. We present an analysis valid over the full range from static contact to hydroplaning that indicates that CMP usually operates in boundary or mixed lubrication mode at contacts and that the lubrication layer is nanometers thick. The results suggest that the sliding solid contact area is mainly responsible for the friction coefficient while both the solid contact and lubricated areas control the removal rate.