Waste stream monitoring in real time can not only provide improved waste management, allowing pretreatment and better disposal options, but also provide a greater insight into the CMP process and provide new knobs to use to optimize the basic process. It offers the potential to put more science into a process dominated by art. End point detection can be real time, not every revolution of the platen. Pad windows, an additional source of wafer non-uniformities, could be eliminated. Tool parameter changes could be triggered off of waste stream analysis instead of time, eliminating blind polishing and improving film thickness control wafer to wafer. Concentrating the solid wastes at the tool could yield savings in water usage, since the reclaimed water could be recycled for less stringent rinsing operations on the same tool. Having a more concentrated solids waste stream can also make slurry recycling more feasible. It is not economically feasible to recycle slurry when it is diluted 100-1000:1 with water.
We're now (January 20th, 2010) past the
official ending (the 18th) of this virtual roundtable discussion, after 4695 views of 129 replies to 18 questions. I'll
edit together Interesting discussions from most of the topics into a
summary document that will be posted to the Planarization Lounge.
We'll leave the topic posting open in case there are additional comments...but they would not be included in the summary.
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