Etch area update, 4/27

Matthias Baenninger mbaennin at
Fri Apr 27 23:51:57 PDT 2012

Dear lab members,

For some of you the Intlvac Ion Beam Mill Etcher at the Stanford Nanocenter (across the road from SNF) might be an alternative. It is a very versatile tool accessible to academic and industrial users. Ion beam processing is a controllable thin film etching technique with independent control of ion energy, ion current density, and incidence angle.
More details can be found at

Please contact me at mbaennin at if you are interested in using the ion mill or have any questions.


Matthias Baenninger, PhD
Goldhaber-Gordon Group
Stanford University
McCullough Bldg., Room 224
476 Lomita Mall
CA 94305-4008

----- Original Message -----
From: "Mary Tang" <mtang at>
To: labmembers at
Sent: Friday, 27 April, 2012 10:26:47 PM
Subject: Etch area update, 4/27

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 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 --

Team Etch

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