System coming back up online for RAITH Champions over the weekend. READ ME ALL!

James Conway jwc at snf.stanford.edu
Fri Jan 7 17:16:45 PST 2005


Greetings:

I was able to restore normal FE-Gun operations after the EHT trip we had 
early this morning.  The Gun continues to run in and it will be expected 
that the emission will slowly increase towards a target of 119 uA over 
the weekend. Currently EHT I is 60.4 uA.  Vacuum has returned to 
7.0E-010 mbar levels which is optimal.

This evening I am running the qualification run at 10 kV, 30 um apt., 5 
mm working distance.  I have saved suitable settings for the Gun/Apt 
alignment and the writefield alignment values to the default mic.ini 
file so all users can accept these values as they come on the system if 
they desire to when prompted.

I have several more issues to resolve on the system related to beam 
blanking leakage concerns and shot dots appearing out of the reduced 
rastering areas.  Note: I was unable to obtain contamination dots as 
would be normal on the system.  However examining the scan raster 
artifacts I do see the minute dot normal artifacts. QED: We do have a 
minute beam but for reasons unknown when we go into spot mode using the 
software something strange may be occurring with the placement or dwell 
time of the dot shots.  What I am observing with longer dwell time shots 
are features several microns in diameter and very diffuse -- as if the 
system loses focus during the shot operation.  Very strange but true.

So after many hours attempting to get through this challenge; I have 
decided to proceed with an extended write of a number of patterns and we 
will examine the EBL results on this chip on Monday.  I am also 
conducting a blanker leakage test to evaluate the beam blankers that 
dwell on a site for various increasing dwell times then moves to a new 
spot and repeats. Thanks go out to Bernd Stegemann at RAITH GmbH whom 
provided this test as a macro for me to run on the system.

Please allow this write to complete in its entirety -- I expect it to 
finish between 6 and 8 PM this evening but it may take longer.  DO NOT 
ABORT THIS WRITE.

I am placing the system on CORAL into 'yellow light mode' and RAITH 
Champions may access the system for their use this weekend but with the 
caveat that I expect these users to promptly report their results and 
provide data and images to me of their EBL results.  This will assist me 
in establishing new baselines for performance for the system.  Many eyes 
are better than one. All other users whom wish to access the system if 
it is not in use by raith champions are requested to call me on my cell 
phone for permission to utilize the system.

Limitations of Use:
NO OPERATIONS ON THE SYSTEM TO EXCEED 15 kV ACCELERATION VOLTAGE.
All materials going into the system shall be baked for 90 sec. on the 90 
degree hot plate in the Ebeam lab, or oven baked at any temperature 
greater than 90 degrees for 30 minutes. This is to ensure we maintain a 
clean system as we condition the system and run in the FE-Gun. 
Please contact me if you have any concerns.

Thank you for your support!

James Conway
cell 415-412-4825


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