Sputter targets and methods of manufacturing same to reduce particulate emission during sputtering

Abstract

Methods for reducing inclusion content of sputter targets and targets so produced are disclosed. Inclusions may be reduced by adding a small amount of Si to the molten Al or molten Al alloy followed by filtering of the molten metals through a filter medium. Targets having substantially no inclusions therein of greater than about 400 μm are especially useful in the sputtering of large flat panel displays and result, upon sputtering, in a reduction in the amount of macroparticles sputtered onto the substrate.

1 . A method of making an aluminum or aluminum alloy sputter target adapted for sputtering of a flat panel display comprising providing molten Al or Al alloy, adding to said molten Al or Al alloy an amount of between about 0.01-2.00 wt % Si to form a molten alloy mixture, forwarding said molten alloy mixture through a filter element to remove inclusions therefrom, and allowing said filtered alloy mixture to solidify.  
     
     
         2 . Method as recited in  claim 1  wherein said filter element is a sintered ceramic filter.  
     
     
         3 . Method as recited in  claim 2  wherein said filter element is a sintered alumina having a grit size of about 2 to about 14.  
     
     
         4 . Method as recited in  claim 3  wherein said filter element has a grit size of about 8.  
     
     
         5 . Method as recited in  claim 1  wherein said Cu is present in said molten alloy in an amount of about 0.01 to 3.00%.  
     
     
         6 . Method as recited in  claim 1  wherein said molten alloy mixture is Al 0.5 Cu 0.5 Si.  
     
     
         7 . Method as recited in  claim 6  wherein after said forwarding of said molten alloy mixture through said filter element said mixture is substantially free of inclusions of the size of about 400 μm or greater therein.