Forming method of silicide film

Abstract

A manufacturing method of a semiconductor device of the present invention is characterized in that a first step of forming a cobalt film 201 on a silicon substrate on which a diffusion layer 200 is formed, a second step for forming a titanium nitride film 202 containing titanium on the cobalt film by a reactive sputtering process using a nitrogen gas and a titanium target from which the nitride film on its surface has been previously removed, and a third step of performing an annealing to react the cobalt film with the silicon substrate, thereby accomplishing silicification.

What is claimed is:  
     
         1 . A forming method of a silicide film comprising the steps of: 
 forming a cobalt film on a silicon substrate on which a diffusion layer is formed,    forming a titanium nitride film containing titanium on said cobalt film, and    performing a heat treatment to react said cobalt film with said silicon substrate, thereby forming a cobalt silicide film.    
     
     
         2 . The forming method of the silicide film according to  claim 1 , wherein said titanium nitride is formed by a reactive sputtering process.  
     
     
         3 . A forming method of a silicide film comprising: 
 a first step of forming a cobalt film on a silicon substrate on which a diffusion layer is formed,    a second step of forming a titanium nitride film containing titanium on said cobalt film in accordance with a reactive sputtering process by the use of a gas containing a nitrogen atom in its composition and a titanium target from which a nitride film on its surface has been previously removed, and    performing a heat treatment to react said cobalt film with said silicon substrate, thereby accomplishing silicification.    
     
     
         4 . The forming method of the silicide film according to  claim 3 , wherein the nitride film on the surface of said titanium target is removed by sputtering said titanium target.  
     
     
         5 . The forming method of the silicide film according to  claim 4 , wherein the nitride film on the surface of said titanium target is removed after said second step.  
     
     
         6 . The forming method of the silicide film according to  claim 3 , wherein said gas containing the nitrogen atom in the composition is a nitrogen gas.  
     
     
         7 . The forming method of the silicide film according to  claim 3 , wherein said second step is performed in a low temperature atmosphere such that a titanium nitride film contains titanium.  
     
     
         8 . The forming method of the silicide film according to  claim 3 , wherein said second step is performed under temperature conditions that a temperature of said silicon substrate is within a range of 50° C. to 100° C.  
     
     
         9 . The forming method of the silicide film according to  claim 3 , wherein said third step comprises: 
 a first annealing step of changing said cobalt film on said diffusion layer to a cobalt monosilicide film, and    a second annealing step of removing said titanium nitride film containing titanium and said unreacted cobalt film, and then changing said cobalt monosilicide film to a cobalt disilicide film under higher temperature conditions than that of said first annealing step.    
     
     
         10 . The forming method of the silicide film according to  claim 9 , wherein the steps of from said first step to said first annealing step in the third step are continuously performed in the same equipment.  
     
     
         11 . A forming method of a titanium nitride film having a reduction function of a natural oxide film comprising: 
 removing impurities on the surface of a titanium target, and    forming the titanium nitride film by a reactive sputtering process using a gas containing a nitrogen atom in its composition.    
     
     
         12 . The forming method of the titanium nitride film according to  claim 11 , wherein said titanium nitride film is a mixed film containing an unreacted titanium.