Subject: Problem raith SNF 2008-04-23 19:15:49: calibration are required to piezo post and mech. adjustments to all sample holders need to be completed
From: jwc@snf.stanford.edu
Date: Wed, 23 Apr 2008 19:15:49 -0700

Greetings:
Thanks to an incredible effort and response by RAITH Field service leader Bernd Steggemann,
whom by chance was traveling through SFO this morning we have effected repairs and replacement
to the ceramic ball mounted on Piezo post three of the XY Laser stage.  The electrical
connection to the Faraday Cup on stage also resolved itself with this repair.
I have tested the Load Lock and Robot arm and exchange position settings for sample
holder transfer.
Just brought the FE-GUN back up and it will take about six hours for emission to stabilize
and possibly a day or more to return to previous emission levels.  vacuum levels are
elevated but safe to resume operations this evening.
I loaded the Universal Sample holder and attempted to level using the Piezo controls,
but was unable to successfully level to any less than a total delta WD of 0.194 mm across
a 96 mm axis across a 100 mm wafer. Note Piezo three is the fixed reference post height
that the others are adjusted to mechanically.
I desire to repeat this measurement again before attempting to perform mechanical adjustments
to both the Universal and Electrostatic chuck sample holders.  Note the Std. sample
holder cannot be adjusted as they are pressed in, its detents are worn, and likely should
soon be replaced or simply discarded.  I will confirm with RAITH USA Inc. if I need
to recalibrate the piezo controls before performing mechanical adjustments.
With some reservations I am releasing the system to experienced users only.  Users should
carefully check their focus and perform a write field alignment within ~ 5 mm of where
they intend to write their patterns.  BE SURE TO center all piezos as you come ontO
the system.
Thank you for your support!
James Conway