CMP TRIBOLOGICAL STUDY OF CARRIER RING PLASTIC MATERIALS

摘要

Understanding the tribological properties of the plastic material used in the retaining or carrier ring is important because the plastic is also polished along with the wafer film in contact mode configurations. The tribological plastic properties are related directly to the carrier ring lifetime as well as influencing certain types of defects. In this study, several types of plastic materials were polished in different chemical mechanical polishing (CMP) environments. Different types of plastic discs of 1″ diameter were polished on a bench top CMP polisher. Silica based oxide and tungsten slurries as well as alumina based copper slurry were used as the basis for simulating different CMP process environments. Relative plastic wear rates, coefficients of friction and acoustic emission signals were measured and analyzed for each CMP process environment studied. Surface studies of the plastic disks were performed through the use of optical microscopy and atomic force microscopy (AFM). Results of this study indicate that the tribological characteristics of a particular plastic are dependent upon the CMP process environment.