Method of making sputtering target

Abstract

A method of making a large Mo billet or bar for a sputtering target wherein two or more bodies comprising Mo are placed adjacent one another (e.g. stacked one on the other) with Mo powder metal present at gaps or joints between the adjacent bodies. The adjacent bodies are hot isostatically pressed to form a diffusion bond at each of the metal-to-Mo powder layer-to-metal joint between adjacent bodies to form a billet or bar that can be machined or otherwise formed to provide a large sputtering target. The number and dimensions of the Mo bodies placed adjacent one another are selected to yield a desired large size the billet or bar suitable for the sputtering target. The billet or bar for the sputtering target exhibits a microstructure comprising equiaxed grains of less than 30 microns grain size and exhibits a low oxygen content of less than about 100 ppm by weight.

1 .- 7 . (canceled) 
     
     
         8 . A billet or bar for a sputtering target and having a first powder preform comprising molybdenum and a second powder preform comprising molybdenum bonded together at a diffusion bond that corresponds to a location where a powder layer comprising molybdenum formerly resided between the first and second preforms. 
     
     
         9 . A sputtering target comprising a first powder preform comprising molybdenum and a second powder preform comprising molybdenum bonded together at a diffusion bond that corresponds to a location where a powder layer comprising molybdenum formerly resided. 
     
     
         10 . A billet or bar for a sputtering target having a HIP'ed microstructure comprising equiaxed grains of grain size of about 30 microns or less and an oxygen content of less than 100 ppm by weight including at a diffusion bond where a powder layer comprising molybdenum formerly resided. 
     
     
         11 . The billet or bar of  claim 10  having the diffusion bond joint where commercially available Mo powder metal having an oxygen content higher than 100 ppm by weight formerly resided. 
     
     
         12 . The target of  claim 9  wherein the diffusion bond corresponds to a location where a layer of commercially available molybdenum powder formerly resided but having a lower oxygen content than commercially available molybdenum powder. 
     
     
         13 . The target of  claim 9  having a HIP'ed microstructure comprising equiaxed grains of grain size of about 30 microns or less. 
     
     
         14 . The billet or bar of  claim 8  wherein the first powder preform and the second powder preform comprise sintered powder bodies comprising Mo. 
     
     
         15 . The target of  claim 9  wherein the first powder preform and the second powder preform comprise sintered powder bodies comprising Mo.