cancelled 9-2 tonight

Lindsay Moore lsmoore at stanford.edu
Wed Feb 11 13:34:57 PST 2004


also, whatever list raith-pcs at snf.stanford.edu is, it does not send email 
to the whole raith list.



  here is the info from charis:
1) Beam current low and fluctuating *a lot*. Last user (John Paul) records 
30pm at 30 micron aperture (compared to 140 usuall). I got 63 +/- 5. At 120 
micron aperture,current was 1.252nA and decreased by 0.01 nA over a five 
minute period. I noticed from the logbook that the current has been 
steadily decreasing over the past 2 days. 2) Column not moving. After 
write, joystick did not move column. Nor did software. I managed to 'fix' 
this by turning off and and on the laser stage control. I suspect that the 
column may not have moved at all during the write, i.e. only one writefield 
was written over and over again.
John Paul, have you developed your write? Did it look like (2) hapened for 
you also? Charis.


and james:
Greetings:
The beam current values (BEAM I) have been falling consistently as the 10 
and 30 um apertures are becoming blocked with hydrocarbons during the 
writes. This is normal and is to be expected especially considering the 
usage we have on the system.
Currently the beam current for the 10 um aperture is 50% of when the 
aperture disk was new.
Currently the beam current for the 30 um aperture is 60 % of when the 
aperture disk was new.
50 % of new maximum is the breakpoint to trigger the PM request. As planned 
and previously announced, we will be doing a column clean with aperture 
replacement PM including a NEW FE-gun tip replacement this next weekend. We 
will be down Friday 10 AM through late Tuesday afternoon. No access no use 
during this period. 40 hour bake out has been requested and will be done 
concurrent with the Monday Holiday.
The system will be requalified for performance and imaging resolution 
before releasing it back to users. Please schedule your work accordingly.
The report of the stage freeze is the first reported in some time... we 
will monitor the situation. If you observe this give time for all macro and 
other operations to be completed then attempt to move the stage a mm or 
more using the Stage control. If this still does work press the STOP SIGN 
in the Stage control window and it will stop all pending operations and 
release the XYZ axis's.
Back to green light mode... writes performed last night by dwshin came ot 
very nice.
Thank you,
JWC

and hatice:
For 30 micron aperture from 11:00 am to 12:30, current changed from from 
56pA to 63, 68, 113, 128, 110. It does not stabilize, it inreases and 
decreases randomly.




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