Statis: RAITH did not pass qualification. System remains in Yellow until fault is determined...

James Conway jwc at snf.stanford.edu
Mon Jan 10 12:01:09 PST 2005


Greetings:

My Raith ebeam qualification run did not pass performance criteria and 
we are not returning the system to users access today.  I will leave the 
system in yellow light mode but may upgrade to red light shutdown status 
if my run this afternoon continues to show the poor EBL results.

The delivered area dose seems to be much higher than we specified.  All 
single shot dots and single pixel lines (SPL's) were written were much 
larger i.e., wider than ever acquired in the past.   Features are too 
large and gross to evaluate stitching.

The PCM qualification run is a series of patterns:

    * 10 X 10 X 1000 um array of origin_targets which contain both
      single shot dots and various raith circles from 25, 50, and 100 nm
      widths overlaid over a normal XY target.  Result: All the ring are
      enormous on the order of 1 - 5 um in width.
    * Several demo.csf patterns which give us much information on area,
      line, and dot doses, high resolution SPL's, deflection test, and
      write field to write field stitching and proximity.  Results:  All
      features written much larger than specified.  Doses appear really
      large by a factor of two!
    * Stitching SOS.csf: stitching pattern gives us write field to write
      field stitching patterns that we can measure automatically.  
      Results:  Features too large to evaluate stitching with.
    * SPL10X10.csf pattern is our new main Process Control Monitoring
      pattern.  This  pattern gives  us a  minimum  SPL  we can
      resolved  and dot shot diameters placed across 2X2 100 um
      stitching fields.  Results:  The dose factor one lines were nearly
      5 um wide.  all dot shot areas fully developed out.  higher dosed
      single pixel lines fully developed out.
    * Line and Space pattern blocks.  This pattern renders minimum
      features we can resolve as area line patterns with increasing
      pitch. No line features were resolved and all pattern blocks fully
      cleared and developed out.
    * Flower pattern:  Deflection and single pixel line test.  Results: 
      Only the lowest dose single pixel lines at dose factor 0.5
      resolved and were microns in size.

Conclusions:
During this qualification run the exposure doses delivered were twice to 
three times that measured on the picoammeter during the set up for this 
run.  The large micron scale features seen during contamination dot shot 
attempts during Fridays session may have been due to either a problem 
with the E/O card or with the spot functions as if we lost focus during 
the shot delivery event.  More test will conducted this afternoon and 
tomorrow afternoon to troubleshoot the cause of this problem.  We are 
currently down on the system in yellow light mode until further notice.

Thank you,

James Conway
01102005: 1200 noon



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