Weekend Update!!!

John Shott shott at stanford.edu
Fri Jun 12 17:34:02 PDT 2009

Pquest Community:

I believe that we have good news to report:  as of 5:20 pm Friday 
evening, the pquest is under vacuum and we believe that we have 
addressed 3 significant issues:

1. We have replaced the ferrofluidic feedthrough that Jim Kruger 
reported to be leaking earlier this week.  Fortunately, we had one of 
the spare, chemical-resistant ones on hand.

2. Elmer and Jim Haydon determined that the old belt driven assembly 
that drives the wafer clamp up and down was likely placing lateral 
torque on the ferrofluidic feedthrough .... resulting in shorter than 
expected life.  They have done a nice (and quick) job of converting it 
to an on-axis direct drive system.  Note: for those of you used to the 
sound of the "whine" as the clamp mechanism drives up and down, be 
forewarned: it's pretty silent now so you won't get the same audible cues.

3. In the process of addressing these issues during final testing, we 
experienced problems with the drive mechanism that moves the wafer arm 
to/from the load lock onto the chuck.  We have disassembled and repaired 
the drive mechanism.   Note: for those of you used to the sound of the 
"click, click, click" as the wafer arm pulls out of the etch chamber, it 
is now also pretty silent.  No more audible cues there either.

Cesar is monitoring the vacuum system now and will make a final check of 
wafer load/unload and wafer clamp operations and will also likely run an 
oxygen plasma as well.

Barring any surprises, I fully expect that Cesar will release the tool 
for use by about 7 p.m. this evening.

We are hopeful that this will allow some of you to get some useful 
etching done over the weekend.  At this point, I believe that the only 
thing yet to be resolved is the delivery and installation of the chuck 
heaters .... so we do not yet have the electrically heated chuck.  Other 
than that, however, I believe that the system to be fully functional.

Good luck and happy processing,


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