edmyers at stanford.edu
Tue Jun 21 16:22:20 PDT 2011
Over the years I would get occasional reports of polishing rate
asperities. This may happen more than I'm aware, since often times
problems or concerns go unreported. During these isolated
excursions, I was never able to find any correlate to these problems.
Recently I have changed out a number of our membranes within a sort
time period. This has resulted in many more reports of polishing
problems. I feel pretty confident there is a correlation to our
membrane assemblies and our polishing rate excursions. I am working
with the US parts supplier and GnP to understand why we are so
sensitive to the changing of the membranes. We are trying to
determine if we received incorrect assemblies, if there is a way to
condition the assemblies or if we need to modernize our wafer heads.
I will keep you appraised to any findings or developments as they become clear.
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