From mtang at snf.stanford.edu  Wed Sep 15 07:37:05 2004
From: mtang at snf.stanford.edu (Mary Tang)
Date: Wed, 15 Sep 2004 07:37:05 -0700
Subject: Reset
Message-ID: <41485391.3B8841B8@snf.stanford.edu>

Hi --

I neglected to write this up yesterday...  and apologize, since it
should really have been put in red, even if for a short time.  The user
yesterday afternoon reported an overload error on the spindle.  When I
got there, the machine was simply locked up.  The user said it looked
like it started cutting in the middle of the wafer when the error
occured.  He was using 150 mm for the wafer diameter (his substrate was
100 mm, ordinary Si).  But he did align to the flat, which is suspected
to be a problem as described in the wafersaw at snf discussions.  Anyway,
the wafer was undamaged, but we unloaded and I reset the machine.

I also reset the machine this morning.  This morning's user said that
the wafer slid off the chuck during the cut so she hit stop/emergency
stop.  The machine was locked up, so I reset it.  The user said she
wasn't sure if the backside of the wafer was really clean, and this may
have affected vacuum quality (though it must have been good enough to
actuate the vacuum switch...)  Will keep an eye on this.

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