Subject: Please carefully check your exposure results and report back to this list. RAITH exposures and/or ZEP-520A exposures?!!!
From: "James W. Conway" <jwc@snf.stanford.edu>
Date: Tue, 15 Dec 2009 17:38:40 -0800

Greetings RAITH Community:

Please take a careful look at your exposure results since last Thursday evening on the RAITH system.
I had one poor possibly out of focus result on an exposure performed yesterday and one second hand report of problems on an exposure last evening.

While this is unlikely -- it may be that we are a at the end of stable emission of the FE-Gun and the Beam Current is changing during the exposure.
Or more likely someone adjusted focus before or while the system was exposing our job.

What we observed was doses delivered were much lower than expected dose to clear our patterns using 250 nm ZEP-520 A.
This is also a brand new freshly opened bottle of ZEP-520A but from a batch near its expiration date.   A new bottle is on order.


FYI:  9:30 to 10 AM tomorrow Wednesday we will be taking the system off line to all Users for our Holiday Shutdown and we will also be performing a full column preventative maintenance procedure as planned.

Thank you for your support!

James Conway