Novel ceria/graphene oxide composite abrasives for chemical mechanical polishing

Abstract

The structure and particle distribution of the abrasive used in chemical mechanical polishing (CMP) directly affect the performance of polishing and quality of the resulting surface. The ceria (CeO2) nanomaterial has been extensively employed in polishing abrasives. Increasing the Ce3+ content is known to improve removal efficiency and enable optimal surface quality. In this study, we increased the Ce3+ content on the CeO2 surface by growing CeO2 nanoparticles in situ on graphene oxide (GO; CeO2@GO) to develop novel composite abrasives for the high-performance CMP of silicon wafers. The designed composite abrasive fully utilized the special structure of GO and the effect on the charge-transfer between CeO2 and GO, which increase the Ce3+ content and number of chemical reaction sites available during the polishing process. This accelerates the generation rate of the oxide layer on the surface of the silicon wafer and increases the removal rate while improving surface quality. The removal rate of the composite abrasives reached 190.58 ± 13 nm/min, which is 50% higher than that of pure CeO2 abrasives. Moreover, the average surface roughness (Ra) of 0.278 ± 0.07 nm within the confines of a 5.0 × 5.0 μm2 region was achieved using the novel composite abrasives. This study offers a straightforward method to enhance the content of Ce3+ in materials and provides a novel route for obtaining efficient composite abrasives.