Method to use a laser to perform the edge clean operation on a semiconductor wafer

Abstract

A method for performing the edge clean operation on a semiconductor wafer. A laser beam is used to accurately clean the edge of the wafer. The wafer is clamped concentrically to a chuck and rotated at a selectable speed, preferably in the range of 10 rpm to 1,000 rpm. A laser beam of variable power is directed onto toward the edge of the wafer at an oblique angle through a nozzle through which an inert purge gas is simultaneously passed. The laser beam removes unwanted deposits at the edge of the wafer and the gas is used to blow away the residue and prevent slag buildup on other parts of the wafer. The process is preferably carried out in an exhausted chamber.

1 . A system used for performing an edge clean operation on a wafer, the system comprising: 
 a rotatable chuck which is configured to clamp the wafer thereon; and    a laser capable of emitting both a laser beam and a gas therefrom for cleaning an edge of the wafer.    
     
     
         2 . A system as defined in  claim 1 , further comprising a rotatable chuck which is configured to concentrically clamp the wafer thereon.  
     
     
         3 . A system as defined in  claim 1 , further comprising a video monitoring system which monitors the edge of the wafer and a point of contact of the laser beam.  
     
     
         4 . A system as defined in  claim 1 , further comprising an exhausted chamber, said chuck and said wafer being positioned within said exhausted chamber.