Abstract
Chemical Mechanical Polishing (CMP) is essential for the manufacturing of recent high-performance electronic device. However, for the CMP process, huge amount of slurry is used, which is to be disposed after being used only once. From the viewpoint of reduction of environmental burdens, this study was made for exploring the possibility of recycling of slurry by focusing on the slurry used for Tungsten CMP. For that purpose, we collected the slurry used for polishing and then tried to reuse it for polishing again. As a method for evaluation, we made comparisons of removal rates between new slurry and recovered slurry. The results shows that when collecting the slurry during CMP, it contained the water remained on the surface of the polishing pad after conditioning, by which slurry was diluted and caused the reduction of removal rate of Tungsten film. However, it was found that when making polishing of Tungsten film using the slurry recovered without being diluted with water, the same level of removal rate as new slurry is obtained.
