From shott at stanford.edu  Sat Feb  7 08:34:45 2009
From: shott at stanford.edu (John Shott)
Date: Sat, 07 Feb 2009 08:34:45 -0800
Subject: Rebuilt diffusion pump ....
Message-ID: <498DB825.8090606@stanford.edu>

MRC Community:

I'm pleased to report that the MRC diffusion pump has been completely 
cleaned and reassembled with a fresh charge of Santovac diffusion pump 
oil.  Thus far vacuum looks good and shows a pressure of 1.2 mTorr with 
20 sccm of oxygen flowing.  It has also been run with 20 minutes of 
argon plasma and no problems were encountered.

While we believe that the system has been fully restored, however, I 
recommend using caution ... and carefully etched and examined test 
wafers .... before committing important wafers to this tool.

During the coming week, I hope to get inputs from Jim McVittie, Elmer, 
Cesar, and others as to what we can to do provide somewhat better 
valving and interlocking on this tool to prevent the type of errors that 
crack and carmelize the pump oil.  In the meantime, please pay special 
attention to the thermocouple gauges and the timing and order in which 
you open/close the roughing, foreline, and gate valves.  This fully 
manual pumping system has no margin for error.

I'd like to personally thank a number of folks for their efforts and 
diligence in removing, cleaning, rebuilding, and replacing this pump in 
a timely fashion: Mike, Elmer, Jim McVittie, Cesar, and Eric all pitched 
in to help expedite this repair.  To get an idea of the challenge they 
faced, I would say that it is equivalent to pouring maple syrup in your 
oven and then baking it at 450 degrees F for several hours .... so extra 
thanks are due to all that helped in this rebuilding effort.

Happy processing,

John