Etch area update, 4/27
mtang at stanford.edu
Fri Apr 27 22:26:47 PDT 2012
Hi all --
I've been told that people want more detail about the status of certain
etch tools. So, I'll try to expand on the daily postings (which can be
found at http://toolstatus.blogspot.com/ and is linked from the SNF home
STSetch2: This is the item of greatest need and concern. As you may
know, the system suffered a massive vacuum chamber leak which took
several weeks to fix. But then, the RF generator which has been
replaced just before shutdown, was found to be out of calibration.
Actually, the generator was good, but we suspect the DeviceNet
communications interface board which was moved from the original to the
replacement generator might also have stored calibrations. So, this
generator was sent out for recalibration. Both this and the original
generator are due back next week, the first one on Monday at 4:30 pm,
the second a few days later. The first, unfortunately, had been delayed
a week, in large part because of recent changes in Procurement
requirements from suppliers. (Ironically, Elmer had made the repair
service feel so bad for our situation, they discounted the price as a
courtesy -- which then required Procurement to authorize the change -
MORE delay!!) Plan A is to install the repaired generator Tuesday and
requalify. If Plan A doesn't work, then Plan B is to try the second
generator, which should have arrived. And yes, a Plan C is in the works.
Lampoly: This generator is also out for repair. It was due back today,
but is delayed into next week because of changes in Procurement procedures.
Amtetcher: The long pumpdowns are due to the hexode not cooling down.
The hexode heats to 30 C when the chamber is open and cools down 23 C
for the etch. The hexode is slightly heated to reduce water adsorption
during the 10 minutes of so of loading wafers when the chamber is
open. To control temperature, the hexode has a valve which controls
the flow of a hot circulating water loop (30 C) and a cold loop (20C).
This valve appears to be leaky or not sealing. Unfortunately, it is an
obsolete part, so some research into possible replacements needs to be
done. In the meantime, because it is a lot more important to keep the
hexode at temperature for etching than it is to heat during loading, the
heating has been disabled for now -- so the hexode will remain at 23 C
whether the chamber is open or closed. We believe this should not
affect most, if any processes, significantly. A quick requalification
was performed to verify etch rates were good.
If you have specific needs or concerns, please contact a staff member --
we can provide more information, and possibly offer suggestions on
backups either at SNF or elsewhere.
Thanks for your attention --
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