Effects of suspending abrasives on the lubrication properties of slurry in chemical mechanical polishing of silicon wafer

The lubrication properties of the slurry between the silicon wafer and the pad in chemical mechanical polishing (CMP) are critical to the planarity of the silicon wafer. Moreover, the suspending abrasives, which are contained in the slurry, have an extremely important influence on the lubrication properties of the slurry. In the CMP process of the large-sized silicon wafers, the influence of suspending abrasives on the slurry becomes more prominent. In order to explore the effects of suspending abrasives on the lubrication properties of the slurry under the light load conditions, a three-dimensional lubrication model based on the micro-polar fluid theory is developed. The effects of suspending abrasives on the fluid pressure acting on the wafer and the distribution of the slurry film between the silicon wafer and the pad are discussed.