From mtang at snf.stanford.edu  Wed Feb 18 16:40:53 2004
From: mtang at snf.stanford.edu (Mary Tang)
Date: Wed, 18 Feb 2004 16:40:53 -0800
Subject: [Fwd: Re: Comment wafersaw 2004-02-18 15:19:05: Failed to perform Y-off 
 alignment]
Message-ID: <40340615.30F2DCF0@snf.stanford.edu>



-------- Original Message --------
Subject: Re: Comment wafersaw 2004-02-18 15:19:05: Failed to perform
Y-off alignment
Date: Wed, 18 Feb 2004 15:47:33 -0800
From: Mary Tang <mtang at snf.stanford.edu>
Organization: Stanford University
To: chungchu at snf.stanford.edu
CC: wafersaw-pcs at snf.stanford.edu, maurice <maurice at snf.stanford.edu>

Hi all --

There have been more recent complaints about the Y-offset alignment on
the wafersaw or that the saw is not cutting at the location expected
(basically, a Y-offset calibration problem).  It seems to me that there
really isn't a problem...  A couple of wafersaw users are now using
different blades, which have slightly different thickness of blade hub
than the blades we normally stock.  This means that the Y-offset may be
off more than usual (maybe a millimeter), instead of just being off by a
few microns as we are normally used to seeing.  This means that you HAVE
to check the Y-offset alignment before you start dicing your device
structures -- which you should be doing anyway, if you are following the
procedures posed (I know, some of us have gotten lazy because it's not
often far off).  And, when you are doing the Y-offset calibration, you
might find that the actual cut is off the video screen (I may be wrong,
but have seen several times that it is further "up", i.e., in the
positive Y-direction, when using the standard aluminum-hub blades from
the Stockroom.)

Hope this helps -- if not, let me know.  And if anyone would like a
refresher on Y-offset, let me know --

Thanks for your attention --

Mary


--
Mary X. Tang, Ph.D.
Stanford Nanofabrication Facility
CIS Room 136, Mail Code 4070
Stanford, CA  94305
(650)723-9980
mtang at stanford.edu
http://snf.stanford.edu