Wet Bench Upgrades
mtang at stanford.edu
Tue May 30 13:04:39 PDT 2006
As you may be aware, SNF is in the process of upgrading the key the wet
benches. We thought we’d take a moment to tell you more about these
The driving force is to upgrade the dump rinsers. As many labmembers
have previously noted (ie., patiently complained), the dump rinsers are
of various vintages and rinse to varying degrees of effectiveness over
varying lengths of time… But as you might suspect, wafer rinsing
technology has advanced significantly in last 25 years. The new dump
rinsers are gentle spray/overflow, which has been shown to result in
fewer particles (because there’s less static generated) and minimize
damage, especially to MEMS devices. In addition, these are also more
water-efficient – largely because they are smaller as they are designed
to hold one 6” cassette instead of two (don’t worry, extra replacement
dump rinsers are being installed in high-use stations to handle peak
demand.) And they have a built-in feature which allows monitoring of
Because the new dump rinsers have a smaller footprint, new layout and
decking is required. So, we have also taken this opportunity to lower
the decking by at least 1 ½” this is to increase headspace to make it
easier to handle cassettes (especially 6”) and pour chemicals. Many
other changes (consistency in layout between benches, improved access
for maintenance, etc.) are also being incorporated as well.
Funding for this upgrade has been provided by a rebate/grant from the
Stanford Facilities & Operations group, as it is anticipated that the
savings in DI water should pay for this upgrade within two years. The
grant, however, stipulates that all upgrade work should be complete by
the end of June in order to qualify, so that puts us on a time schedule.
So far, wbmetal, wbnonmetal, and wbsilicide are now complete (if you
haven’t done so already, check them out – they are beautiful!) Granted,
things haven’t gone quite as smoothly as we’d like and there are a few
issues that still need to be addressed – but we’d like to ask everyone
to realize the complexity of this upgrade and the timeline under which
it needs to be accomplished.
Two more things. first, a word about logistics… “wbdiff” is slated to be
upgraded this week. “wbsilicide” will serve as the backup until wbdiff
is functional again. wbsilicide will be decontaminated this afternoon
and will be unavailable for use as a semiclean station or for
decontamination until wbdiff is back to general use. In coming weeks,
wbnitride (which because of the nitride pot will not have a lowered
deck) and wbmiscres/headway2 (which will have a stainless deck installed
for cleanliness/contamination) will be upgraded -- Check the email
archives/Coral for updates and other specific info. When you use these
upgraded stations, please do take good care of them (clean up after
yourself, rinse away any chemical drops, etc.) and do note any problems
that you encounter.
Second, Jim Haydon deserves ALL the credit for making this happen. While
assembling wbgeneral2, he realized that the new dump rinsers could
benefit the rest of the lab. He then consulted with process staff, did
the research, and came up with the grant proposal to Facilities &
Operations. He has also worked with lab- and staff- members to come up
with improvements that could be incorporated with the basic upgrade.
Thus, Jim’s project will not only have the environmental impact of
saving water, but improve the safety and ergonomics for users and
improve our ability to keep these stations clean and functional.
Again, we ask you for your forebearance and thank you for your patience
while these upgrades are being done.
Your SNF Staff
Mary X. Tang, Ph.D.
Stanford Nanofabrication Facility
CIS Room 136, Mail Code 4070
Stanford, CA 94305
mtang at stanford.edu
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