Removal of metal oxidation

Abstract

A method of preparing an oxidized metal surface is disclosed. The oxidized metal is placed in a controlled environment and carbon monoxide is allowed to flow over the oxidized metal while the controlled environment is maintained at temperature level where the metal oxide becomes less stable than carbon dioxide so that the carbon monoxide reacts with the metal oxide to form carbon dioxide, which is removed from the controlled environment.

1 . A method of preparing an oxidized nickel surface for a semiconductor assembly during a semiconductor fabrication process comprising: 
 exposing the semiconductor assembly having an oxidized nickel portion, to carbon monoxide while in a controlled environment and at a temperature that causes the reaction: NiO(s)+CO(g) Ni(s)+CO 2 (g).    
   
   
       2 . The method of  claim 2 , wherein the temperature is a temperature at which carbon dioxide is more stable than carbon monoxide.  
   
   
       3 . The method of  claim 1 , wherein the temperature is in a temperature range of greater than 475° C. and less than 720° C.  
   
   
       4 . A method of preparing an oxidized nickel surface for a semiconductor assembly during a semiconductor fabrication process comprising: 
 placing a semiconductor wafer, having a nickel portion, into a processing chamber; and    flowing carbon monoxide over the semiconductor wafer while maintaining the processing chamber at temperature ranging between where the carbon monoxide is a more stable compound than a nickel oxide (NiO) compound and less than 720° C., such that the carbon monoxide reacts with the nickel oxide present to form carbon dioxide and to create a nickel surface substantially free of oxide.    
   
   
       5 . The method of  claim 4 , wherein the temperature where the carbon monoxide is a more stable compound than the nickel oxide (NiO) compound is approximately greater than 475° C.  
   
   
       6 . A method for preparing an oxidized nickel surface comprising: 
 placing an oxidized nickel in a controlled environment; and    flowing carbon monoxide over the oxidized nickel while maintaining the controlled environment at a temperature level where nickel oxide becomes less stable than carbon dioxide so that the presence of the carbon monoxide reacts with the nickel oxide to form carbon dioxide that is removed from the controlled environment.    
   
   
       7 . A semiconductor fabrication process for preparing an oxidized nickel surface comprising: 
 placing an oxidized nickel in a controlled environment; and    flowing carbon monoxide over the oxidized nickel while maintaining the controlled environment at a temperature level where nickel oxide becomes less stable than carbon dioxide so that the presence of the carbon monoxide reacts with the nickel oxide to form carbon dioxide that is removed from the controlled environment.    
   
   
       8 . A method of preparing an oxidized nickel surface for a semiconductor assembly during a semiconductor fabrication process comprising: 
 placing a semiconductor mounting member having a nickel portion, into a processing chamber; and    flowing carbon monoxide over the semiconductor mounting member while maintaining the processing chamber at temperature range of greater than 475° C. and less than 720° C., such that the carbon monoxide reacts with any nickel oxide present to form carbon dioxide and to create a nickel surface substantially free of oxide.    
   
   
       9 . The method of  claim 8 , wherein said semiconductor mounting member comprises a printed circuit board.  
   
   
       10 . A method of preparing an oxidized cobalt surface for a semiconductor assembly during a semiconductor fabrication process comprising the step of: 
 exposing the semiconductor assembly having an oxidized cobalt portion, to carbon monoxide while in a controlled environment and at a temperature that causes the reaction: CoO(s)+CO(g) Co(s)+CO 2 (g).    
   
   
       11 . The method of  claim 10 , wherein the temperature is a temperature at which carbon dioxide is more stable than carbon monoxide.  
   
   
       12 . The method of  claim 11 , wherein the temperature is in a temperature range of greater than 500° C. and less than 720° C.  
   
   
       13 . A method of preparing an oxidized cobalt surface for a semiconductor assembly during a semiconductor fabrication process comprising: 
 placing a semiconductor wafer, having a cobalt portion, into a processing chamber; and    flowing carbon monoxide over the semiconductor wafer while maintaining the processing chamber at temperature ranging between where the carbon monoxide is a more stable compound than a cobalt oxide (CoO) compound forming the oxidized cobalt surface and less than 720° C., such that the carbon monoxide reacts with the cobalt oxide present to form carbon dioxide and to create a cobalt surface substantially free of oxide.    
   
   
       14 . The method of  claim 13 , the temperature where the carbon monoxide is a more stable compound than the cobalt oxide (CoO) compound is approximately greater than 475° C.  
   
   
       15 . A method for preparing an oxidized cobalt surface comprising: 
 placing an oxidized cobalt in a controlled environment; and    flowing carbon monoxide over the oxidized cobalt while maintaining the controlled environment at a temperature level where cobalt oxide becomes less stable than carbon dioxide so that the presence of the carbon monoxide reacts with the cobalt oxide to form carbon dioxide that is removed from the controlled environment.    
   
   
       16 . A semiconductor fabrication process for preparing an oxidized cobalt surface comprising: 
 placing an oxidized cobalt in a controlled environment; and    flowing carbon monoxide over the oxidized cobalt while maintaining the controlled environment at a temperature level where cobalt oxide becomes less stable than carbon dioxide so that the presence of the carbon monoxide reacts with the cobalt oxide to form carbon dioxide that is removed from the controlled environment.    
   
   
       17 . A method for preparing an oxidized cobalt surface comprising: 
 placing an oxidized cobalt material in a controlled environment; and    flowing carbon monoxide over the oxidized nickel material while maintaining the controlled environment at a temperature level where cobalt oxide becomes less stable than carbon dioxide so that the presence of the carbon monoxide reacts with any cobalt oxide to form carbon dioxide that is removed from the controlled environment.    
   
   
       18 . A method of preparing an oxidized cobalt surface for a semiconductor assembly during a semiconductor fabrication process comprising: 
 placing a semiconductor mounting member having a cobalt portion, into a processing chamber; and    flowing carbon monoxide over the semiconductor mounting member while maintaining the processing chamber at temperature range of greater than 500° C. and less than 720° C., such that the carbon monoxide reacts with any cobalt oxide present to form carbon dioxide and to create a cobalt surface substantially free of oxide.    
   
   
       19 . The method of  claim 18 , wherein said semiconductor mounting member comprises a printed circuit board.  
   
   
       20 . A method of preparing an oxidized metal surface for a printed circuit board comprising: 
 exposing the printed circuit board having an oxidized metal portion, to carbon monoxide while in a controlled environment and at a temperature that causes the reaction: [M]O(s)+CO(g) [M](s)+CO 2 (g), where [M] is a metal.    
   
   
       21 . The method of  claim 20 , wherein the reaction [M]O(s)+CO(g) [M](s)+CO 2 (g) is a reaction selected from the group consisting essentially of CoO(s)+CO(g) Co(s)+CO 2 (g), NiO(s)+CO(g) Ni(s)+CO 2 (g) and CoO(s)+CO(g) Co(s)+CO 2 (g).  
   
   
       22 . The method of  claim 20 , wherein the temperature is a temperature at which carbon dioxide is more stable than carbon monoxide.  
   
   
       23 . The method of  claim 21 , wherein the temperature is in a temperature range of greater than 65° C. and less than 720° C. for the reaction CuO(s)+CO(g) Cu(s)+CO 2 (g).  
   
   
       24 . The method of  claim 21 , wherein the temperature is in a temperature range of greater than 475° C. and less than 720° C. for the reaction NiO(s)+CO(g) Ni(s)+CO 2 (g).  
   
   
       25 . The method of  claim 21 , wherein the temperature is in a temperature range of greater than 500° C. and less than 720° C. for the reaction CoO(s)+CO(g) Co(s)+CO 2 (g).