Process for making dense mixed metal Si3N4 targets

Abstract

A composition and method for fabricating high-density Ta-Al-O, Ta-Si-N, and W-Si-N sputtering targets, having particular usefulness for the sputtering of heater layers for ink jet printers. Compositions in accordance with the invention comprise a metal component, Si 3 N 4 , and a sintering aid so that the targets will successfully sputter without cracking, etc. The components are combined in powder form and pressure consolidated under heated conditions for a time sufficient to form a consolidated blend having an actual density of greater than about 95% of the theoretical density. The consolidated blend may then be machined so as to provide the final desired target.

1 . Composition comprising Me, Si 3 N 4 , and a sintering aid wherein Me is a member selected from the group consisting of Groups IVB, VB, VIB and VIII of the periodic table, said Me being present in an amount of between about 40-80 atomic percent, said Si 3 N 4  being present in an amount of between about 60 and 20 atomic percent, with the combined atomic percent of said Me and Si 3 N 4  being 100 atomic percent; said sintering aid being chosen from the group of MgO and SiO and being present in an amount of between about 0.05-30 weight percent based on the weight of said Si 3 N 4 . 
   
   
       2 . Composition as recited in  claim 1  wherein Me is selected from W, Ta, Nb, Zr, Hf, Pt, Ir, Mo and Ru. 
   
   
       3 . Composition as recited in  claim 2  wherein said sintering aid is MgO and Me is W. 
   
   
       4 . Sputter target comprising Me, Si 3 N 4  and a sintering aid wherein Me is a member selected from the group consisting of groups IVB, VB, VIB and VIII of the periodic table, said Me being present in an amount of between about 40-80 atomic percent, said Si 3 N 4  being present in an amount of between about 60 and 20 atomic percent, with the combined atomic percent of said Me and Si 3 N 4  being 100 atomic percent; said sintering aid being chosen from the group of MgO and SiO and being present in an amount of between about 0.05-30 weight percent based on the weight of said Si 3 N 4 . 
   
   
       5 . Sputter target as recited in  claim 4  wherein Me is selected from W, Ta, Nb, Zr, Hf, Pt, Ir, Mo and Ru. 
   
   
       6 . Sputter target as recited in  claim 5  wherein said sintering aid is MgO and Me is W. 
   
   
       7 . Sputter target comprising W, Si 3 N 4  and MgO present as a sintering aid, said W being present in an amount of between about 40-80 atomic percent, said Si 3 N 4  being present in an amount of between about 60 and 20 atomic percent, with the combined atomic percent of said W and Si 3 N 4  being 100 atomic percent; said MgO being present in an amount of between 0.05-30 weight percent based on the weight of said Si 3 N 4 . 
   
   
       8 . Sputter target as recited in  claim 7  having a density of at least 95% of theoretical density. 
   
   
       9 . Sputter target as recited in  claim 8  wherein W is present in an atomic amount of about 60 percent, said Si 3 N 4  is present in an amount of about 40 atomic percent and said MgO is present in an amount of about 0.05-6 weight percent based on the weight of said Si 3 N 4 . 
   
   
       10 . Sputter target as recited in  claim 9  having a bulk density of between about 6.9 and 7.3 g/cc. 
   
   
       11 . Sputter target as recited in  claim 9  having a purity greater than 99.9%. 
   
   
       12 . Sputter target as recited in  claim 9  having a purity greater than 99.99%. 
   
   
       13 . Sputter target as recited in  claim 9  having a Nitrogen content of between about 12.3-13.3 weight percent and a Silicon content of between about 19 and 21 weight percent silicon.