Study on the copper-chemical mechanical polishing method using water-soluble fullerenol slurry -investigation of polishing performance

Chemical mechanical polishing (CMP) is a key process used for the multilayer copper interconnects. In recent years, the most common problem encountered in this regard is the inability of conventional abrasive grains to adapt to the next-generation semiconductors owing to their large particle sizes. Hence, this study proposes a water-soluble fullerenol (C_6o(OH) ₃₆) as a novel abrasive grain for Cu-CMP because of its advantageous features such as high water solubility and uniformity of particle size (1 nm); further, there is no risk of contamination of the metal when using C _6o(OH)₃₆). In this paper, the excellent grain abrasive properties of C_6o(OH)₃₆) and its chemical affinity for copper are reported. It is experimentally confirmed that owing to its high chemical reactivity, a slurry containing C_6o(OH)₃₆) can be used to improve the rms surface roughness from 20 to 0.5 nm.