Sputtering targets and method for the preparation thereof

Abstract

Sputtering targets comprising sub-stoichiometric titanium dioxide, TiO x , where x is below 2, are provided. The targets are preferably formed by plasma spraying so as to have an electrical resistivity of less than 0.5 ohm.cm.

1 . A sputtering target which comprises sub-stoichiometric titanium dioxide, TiO x , where x is below 2.  
     
     
         2 . A sputtering target as claimed in  claim 1  wherein the TiO x  is coated onto an electrically conductive base.  
     
     
         3 . A process for the preparation of a sputtering target as claimed in  claim 1  or  claim 2 , which process comprises plasma spraying titanium dioxide, TiO 2 , onto a target base.  
     
     
         4 . A process as claimed in  claim 3  wherein the target base is cooled during the plasma spraying.  
     
     
         5 . A process as claimed in  claim 3  or  claim 4  wherein the plasma spraying is carried out using argon as the plasma gas and hydrogen as the secondary plasma gas.  
     
     
         6 . A process as claimed in any one of  claims 3  to  5  wherein the target bas e is titanium.  
     
     
         7 . A process as claimed in any one of  claims 3  to  6  wherein the titanium dioxide which is plasma sprayed has particle size in the range of from 1 to 60 micrometers.  
     
     
         8 . A process for coating a substrate surface with titanium dioxide, which process comprises the use as a sputtering target of a target as claimed in  claim 1  or  claim 2 .  
     
     
         9 . A process as claimed in  claim 8  wherein the sputtering from the target is carried out using as the plasma gas argon, a mixture of argon and oxygen, a mixture or argon and nitrogen, or a mixture of nitrogen and oxygen.  
     
     
         10 . A process as claimed in  claim 9  wherein the plasma gas comprises 70 to 90% by volume argon and 30 to 10% by volume oxygen.  
     
     
         11 . A process as claimed in any one of  claims 8  to  10  wherein the substrate which is coated is optical glass, the screen of a cathode ray tube, a flexible film or an oxygen barrier film.  
     
     
         12 . A substrate which has been coated by a process as claimed in any one of  claims 8  to  11 .  
     
     
         13 . A process for the preparation of sub-stoichiometric titanium dioxide, TiO x , where x is below 2 which process comprises subjecting titanium dioxide to a plasma flame.  
     
     
         14 . A process as claimed in  claim 13  wherein titanium dioxide is sprayed through a plasma flame.  
     
     
         15 . A process as claimed in  claim 13  wherein the titanium dioxide is sprayed using a combustion flame.