Recent problems and a way around them.

Nancy Latta latta at snf.stanford.edu
Fri Jul 20 11:05:21 PDT 2001


Folks,

First, do not attempt to take the machine out of a locked-up condition
unless you are a specially trained advanced user.  There are only two of
them; Beth Pruitt and Aaron Partridge.  Any attempts by untrained users
may result in very serious damage to the etcher, including the
possiblity of ruining the $30K turbo pump.

As many of you know, we have been experienceing some very frustrating
problems with the etcher.  The major error message that we have seen is
along the lines of 'clamp time exceeded'.  Once this error is achieved
the machine is fully locked up and will need an advanced user to re-boot
it.

What follows is a method by which we may keep the machine operational. 
It requires careful observation on your part as you use the system.  If
you feel you cannot keep a close watch on your run, please cancel your
reservation.

The problem seems to be that the slit valve between the laocdlock and
chamber will not close after a wafer is loaded into the chamber.  When
loading, watch the graphic representation on the PC screen.  After the
wafer is placed on the chuck in the chamber the transfer arm withdraws. 
Once it has cleared the slit valve there is about a 4-5 second pause
before the valve closes.  It makes a 'cheeesck' sound.

If that sound does not occur follow this procedure.  You have about 10
secs to start before the error message shows and you'll need an advanced
user to make the machine right again.

1.  Abort the tranfer by clicking on abort in the tranfer window on the
PC screen.  This should close the slit valve.

2.  Unload your wafer.

3.  Load your wafer again.  This time the valve should close and life
will be good again.

Again, if you feel this procedure is too much to follow, or if you think
that you will not be able to pay close attention to your work, please
cancel your reservation and wait until we get this sorted out.

				Nancy



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