Method of making sputtering target and target produced

Abstract

Method of making a sputtering target includes the steps of melting a metallic target material, controlling the temperature of the melted target material in a manner that the melted target material has almost no superheat, introducing the melted target material into a mold having interior walls forming a mold cavity in the shape of the desired target, and solidifying the melted target material in the mold by extracting heat therefrom at a rate to solidify it to form a sputtering target having a cellular nondendritic microstructure uniformly throughout the target. A sputtering target is provided comprising a metallic target material having a substantially equiaxed, cellular nondendritic microstructure uniformly throughout the target.

1 . Method of making a sputtering target, including the steps of melting a metallic target material, controlling the temperature of the melted target material in a manner that the melted target material has almost no superheat, introducing the melted target material into a mold having interior walls forming a mold cavity in the shape of the desired target, and solidifying the melted target material in the mold by extracting heat therefrom at a rate to solidify it to form a sputtering target having a cellular nondendritic microstructure uniformly throughout the target.  
   
   
       2 . The method of  claim 1  including heating the mold before introducing the melted target material to a high enough elevated mold temperature to prevent substantial columnar grain formation directly adjacent interior walls of the mold  
   
   
       3 . The method of  claim 1  wherein the temperature of the melted target material is controlled within 0 to 20 degrees F. of the melting point of the target material.  
   
   
       4 . The method of claim further including hot isostatic pressing the solidified sputtering target.  
   
   
       5 . The method of  claim 1  wherein heat is extracted at a rate to produce an ASTM grain size of 3 or less in the as-cast sputtering target.  
   
   
       6 . The method of  claim 1  wherein the mold comprises a ceramic, graphite, or metallic mold.  
   
   
       7 . The method of  claim 1  wherein the temperature of the melted target material is controlled by reducing power supplied to an induction coil.  
   
   
       8 . The method of  claim 1  including solidifying the target material to a target shape that requires minimal machining.  
   
   
       9 . The method of  claim 1  wherein the target material comprises a cobalt based alloy including an alloying element selected from the group consisting of boron, chromium, platinum, tantalum, ruthenium, niobium, copper, vanadium, silicon, silver, gold, iron, aluminum, zirconium, and nickel.  
   
   
       10 . A sputtering target, comprising a metallic target material having a substantially equiaxed, cellular nondendritic microstructure uniformly throughout the target.  
   
   
       11 . The target of  claim 8  having a grain size of ASTM 3 or less.  
   
   
       12 . The target of  claim 8  which is densified by hot isostactic pressing.  
   
   
       13 . The target of  claim 10  which comprises a cobalt based alloy including an alloying element selected from the group consisting of boron, chromium, platinum, tantalum, ruthenium, niobium, copper, vanadium, silicon, silver, gold, iron, aluminum, zirconium, and nickel.