Sputtering targets and method for the preparation thereof

Abstract

A process for the preparation of a sputtering target which comprises sub-stoichiometric titanium dioxide, TiO x , where x is below 2, having an electrical resistivity of less than 0.5 ohm.cm, optionally together with niobium oxide, which process comprises plasma spraying titanium dioxide, TiO 2 , optionally together with niobium oxide, onto a target base in an atmosphere which is oxygen deficient and which does not contain oxygen-containing compounds, the target base being coated with TiO x , which is solidified by cooling under conditions which prevent the sub-stoichiometric titanium dioxide from combining with oxygen.

Claims:  
     
         1 . A process for the preparation of a sputtering target which comprises sub-stoichiometric titanium dioxide, TiO x , where x is below 2 having an electrical resistivity of less than 0.5 ohm.cm, optionally together with iiiobium oxide, which process comprises plasma spraying titanium dioxide, TiO 2 , optionally together with niobium oxide, onto a target base in an atmosphere which is oxygen deficient and which does not contain oxygen-containing compounds, the target base being coated with TiO x  which is solidified by cooling under conditions which prevent the sub-stoichiometric titanium dioxide from combining with oxygen.  
     
     
         2 . A process as claimed in  claim 1  wherein the target base is water cooled during the plasma spraying.  
     
     
         3 . A process as claimed in  claim 1  or  claim 2  wherein the plasma spraying is carried out using argon as the plasma gas and hydrogen as the secondary plasma gas.  
     
     
         4 . A process as claimed in any one of the preceding claims wherein the target base is titanium, stainless steel, aluminium or copper.  
     
     
         5 . A process as claimed in  claim 4  wherein the target base is a rotatable target or a flat magnetron target.  
     
     
         6 . A process as claimed in any one of the preceding claims wherein the titanium dioxide which is plasma sprayed has particle size in the range of from 1 to 60 micrometres.  
     
     
         7 . A process as claimed in any one of the preceding claims wherein the titanium dioxide is plasma sprayed together with Nb 2 O 3 .  
     
     
         8 . A process as claimed in any one of the preceding claims wherein the sub-stoichiometric titanium dioxide, TiO x , has a value of x in the range of from 1.55 to 1.95.  
     
     
         9 . A process as claimed in any one of the preceding claims wherein the sputtering target has an electrical resistivity of about 0.02 ohm.cm.  
     
     
         10 . A sputtering target comprising substoichiometric titanium dioxide whenever prepared by a process as claimed in any one of the preceding claims.  
     
     
         11 . A sputtering target as claimed in  claim 10  which has an electrical resistivity of about 0.02 ohm.cm.  
     
     
         12 . A process for the preparation of substoichiometric titanium dioxide, TiO X  where x is below 2 having an electrical resistivity of less than 0.1 ohm.cm which process comprises subjecting titanium dioxide to a plasma treatment in an atmosphere which is oxygen deficient and which does not contain any oxygen-containing compounds.  
     
     
         13 . A process as claimed in  claim 12  wherein the titanium dioxide is sprayed through a plasma flame having a temperature of above 2000° C.  
     
     
         14 . A process as claimed in  claim 13  wherein the plasma flame uses a mixture of hydrogen and argon as the plasma gas.