Continuous Casting of Copper to Form Sputter Targets

Abstract

Continuous casting of copper to produce sputter targets ( 20 ). The resulting targets comprise a relatively low amount of inclusions therein and will result in reduced particulate sputtering leading to a more uniform coating that is sputtered onto the desired substrate.

1 . A method of making a sputter target comprising continuously casting molten copper into a solidified mass, forming a target blank from said solidified mass, and shaping said blank into the required shape for a sputter target.  
   
   
       2 . Method as recited in  claim 1  wherein said sputter target has less than about 2,000 inclusions therein of 0.4 microns and greater as measured over an area of 2890679.7 um 2 .  
   
   
       3 . Method as recited in  claim 2  wherein substantially all of said inclusions have a maximum particle size of about 10 microns.  
   
   
       4 . Method as recited in  claim 1  wherein said continuous casting comprises chilling said molten copper in a graphite or copper mold.  
   
   
       5 . Method as recited in  claim 4  wherein said continuous casting includes water and/or air spray chilling copper exiting from said mold.  
   
   
       6 . Method as recited in  claim 5  wherein, prior to said chilling in a graphite or copper mold, said molten copper is passed through a ceramic or graphite nozzle.  
   
   
       7 . Method as recited in  claim 3  wherein said step of shaping comprises hydroforming said blank into a substantially cup shaped target.