Tantalum sputtering target and method of manufacture

Abstract

Described is a method for producing high purity tantalum, the high purity tantalum so produced and sputtering targets of high purity tantalum. The method involves purifying starting materials followed by subsequent refining into high purity tantalum.

1 - 30 . (canceled)  
   
   
       31 . A high purity tantalum powder comprising greater than or equal to 99.95 weight percent (wt %) tantalum on a total metals basis, less than 500 parts per million by weight (ppmw) total metallic impurities, less than 50 ppmw tungsten or molybdenum, and less than 10 ppmw niobium.  
   
   
       32 . The powder of  claim 31  comprising less than 20 ppmw tungsten or molybdenum.  
   
   
       33 . The powder of  claim 31  comprising less than 5 ppmw each of tungsten and molybdenum.  
   
   
       34 . The powder of  claim 31  comprising less than 5 ppmw total of tungsten and molybdenum.  
   
   
       35 . The powder of  claim 31  comprising less than 20 ppmw total of tungsten, molybdenum, and niobium.  
   
   
       36 . The powder of  claim 31  comprising less than 5 ppmw total of tungsten, molybdenum, and niobium.  
   
   
       37 . The powder of  claim 31  comprising less than 3 ppmw niobium.  
   
   
       38 . The powder of  claim 31  comprising less than 100 ppmw oxygen.  
   
   
       39 . The powder of  claim 31  comprising less than 25 ppmw oxygen.  
   
   
       40 . The powder of  claim 31  comprising less than 10 parts per billion by weight (ppbw) uranium and thorium.  
   
   
       41 . An ingot formed from the powder of  claim 31 .  
   
   
       42 . A sputtering target blank formed from the powder of  claim 31 .  
   
   
       43 . A sputtering target blank comprising greater than or equal to 99.95 weight percent (wt %) tantalum on a total metals basis, less than 500 parts per million by weight (ppmw) total metallic impurities, and less than 5 ppmw total of tungsten, molybdenum, and niobium.  
   
   
       44 . The blank of  claim 43  comprising less than 25 ppmw oxygen.  
   
   
       45 . The blank of  claim 43  comprising less than 10 parts per billion by weight (ppbw) uranium and thorium.