Particle problem resolved

Brian Joseph Greene bgreene at stanford.edu
Thu Apr 19 11:36:55 PDT 2001


Folks,
  Len took the lampoly apart and performed a wet clean of both loadlock
chambers and the etch chamber.  (Thanks Len!)
 Last night, I ran the post-wet clean procedure and inspected several
wafers for particles.  At the end of the procedure, I ran 15 bare silicon
wafers through Etch #1 (ME=60s OE=60s) to season the chamber.  Close
observation of the last few wafers revealed no particles with the un-aided
eye, and less than 8 particles per wafer were visible by eye under the UV
lamp.  There were no particles visible under the microscope with 5x dark
field setup.
  When I ran 15 silicon wafers through the system this morning, I found
the number of particles had doubled.  I would recommend that users inspect
their seasoning wafers carefully.  All of my seasoning wafers looked good
to the unaided eye, but the particles were very apparent when the wafers
were placed under the UV lamp.  The lamp is now located behind the
Gryphon.  Please use it to inspect your wafers, and record unusual
particle counts in the log book.

-Brian
  
_____________________________________________________________
  Brian J. Greene                 Office: CIS-X 128X         
  Applied Physics Dept, MC 4090   Phone: (650) 723-4194 ext 5 
  Stanford University             Pager: (650) 354-9687       
  Stanford, CA  94305-4090        Fax: (650) 723-4659 







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