Benefits of POU Blending on CMP Slurry Pot Life

摘要

One of the main advantages of point-of-use (POU) blending is that it eliminates slurry pot life issues and improves process repeatability by ensuring that the slurry is the same 'age' wafer after wafer. This also reduces consumption of unstable components often utilized in tungsten CMP processes (i.e. H_2O_2) and hence overall tool CoO, because spiking of these chemicals in the sub-fab daytank is no longer required. This paper summarizes preliminary results of a joint study between EKC Technology and BOC Edwards to explore the effects of POU blending on slurry pot life and removal rates in tungsten CMP applications. The BOC Edwards PrIME~(TM) (Precision Integrated Mix Engine) POU slurry blender demonstrates clear advantages over traditional daytank mixing. This POU mixer has shown the ability to reproduce slurry blends to achieve repeatable tungsten removal rates over extended periods of time.