Reclaiming virgin test wafers

Abstract

A method and system for reclaiming virgin test wafers by polishing a very thin layer from the wafer surface, applying a low down force between the wafer and the pad, with a dilute, low basic slurry. By polishing only a few hundred Angstroms of silicon from the wafer surface, a virgin test wafer may be repeatedly reclaimed and reused for periodic defect monitoring.

1 - 10 . (canceled).  
     
     
         11 . A system comprising: 
 a polishing platen having a polishing pad mounted thereon, the polishing platen rotatable at between about 10 revolutions per minute and about 100 revolutions per minute; and    a polishing head to hold a semiconductor wafer and urge the wafer against the polishing pad at a down force pressure of between about 0.05 pounds per square inch and about 4.5 pounds per square inch.    
     
     
         12 . The system of  claim 11  further comprising a dispenser to hold an abrasive slurry and dispense the slurry onto the polishing pad.  
     
     
         13 . The system of  claim 11  further comprising a rotatable pad conditioner having a plurality of soft bristles mounted on pellets.  
     
     
         14 . The system of  claim 11  wherein the polishing head is rotatable.  
     
     
         15 . The system of  claim 11  wherein the total material removed is less than about 500 Angstroms.