Hello,

  I have just inherited a Cobilt mask aligner (rebuilt and renamed by
Quintel Corp). Its a simple manual load machine for 4 " wafers. I
understand from a number of process people I have toured thru our
facility that this machine is a bit of a classic (ie everybody had one
at one time and lots of product was pushed thru these tools). I also
understand that alot of people modified the basic design to improve its
performance.

  What I am looking for is some of this knowledge (lore). The machine
will be in a university lab, so thru put is not an issue, but I need
good resolution (1 um or better) and good overlay. I understand the
machine presently has good resolution, but overlay is a problem (the
chuck shifts when the wafer is put into contact with the mask. So, if
anyone has any comments on maintaining this machine, how to improve the
machine, or any other comments, would you please e-mail me. Any stories
or hints would be greatly appreciated.


   Thank you

     Ken Westra
     westra@amc.ab.ca
     (403) 492 5570 ext 234
     fax: (403) 492 1643