Semiconductor device and fabricating method thereof

Abstract

First, a lower layer wiring is formed on a semiconductor substrate. Then, an interlayer insulating film is formed on the lower layer wiring. Next, a first Ti film is formed on the interlayer insulating film. Thereafter, a TiN film is formed on the first Ti film. Then, a via hole is formed in the TiN film, the first Ti film and the interlayer insulating film such as to reach the lower layer wiring. Then, a second Ti film and an Al or Al alloy film are sequentially formed in the via hole and on the TiN film. Next, a thermal treatment is carried out, thereby allowing Ti in the second Ti film and Al in the Al or Al alloy film to react with each other in a bottom of the via hole.

What is claimed is:  
     
         1 . A semiconductor device comprising: 
 a semiconductor substrate;    a lower layer wiring formed on said semiconductor substrate;    an interlayer insulating film formed on said lower layer wiring;    a via hole formed in said interlayer insulating film and reaching said lower layer wiring;    a barrier metal film embedded in a bottom of said via hole and made of refractory metal;    a conductive film formed on said barrier metal film; and    an upper layer wiring and having a first Ti film, a TiN layer, a second Ti film and an Al or Al alloy film which are sequentially laminated on said interlayer insulating film, said upper layer wiring being connected to said conductive film.    
     
     
         2 . The semiconductor device according to  claim 1 , wherein said barrier metal film comprises a third Ti film having a thickness of equal to or less than 300 Å.  
     
     
         3 . The semiconductor device according to  claim 1 , wherein said lower layer wiring contains Al.  
     
     
         4 . The semiconductor device according to  claim 2 , wherein said lower layer wiring contains Al.  
     
     
         5 . A fabricating method of a semiconductor device comprising the steps of: 
 forming a lower layer wiring on a semiconductor substrate;    forming an interlayer insulating film on said lower layer wiring;    forming a first Ti film on said interlayer insulating film;    forming a TiN film on said first Ti film;    forming a via hole in said TiN film, said first Ti film and said interlayer insulating film so as to reach said lower layer wiring;    sequentially forming a second Ti film and an Al or Al alloy film in said via hole and on said TiN film; and    carrying out a thermal treatment, thereby allowing Ti in said second Ti film and Al in said Al or Al alloy film to react with each other in a bottom of said via hole.    
     
     
         6 . The fabricating method of a semiconductor device according to  claim 5 , wherein a temperature of said thermal treatment in said step for allowing said Ti and said Al to react with each other is equal to or higher than 300° C.  
     
     
         7 . The fabricating method of a semiconductor device according to  claim 5 , wherein a thickness of said second Ti film in said bottom of said via hole is equal to or less than 300 Å.  
     
     
         8 . The fabricating method of a semiconductor device according to  claim 6 , wherein a thickness of said second Ti film in said bottom of said via hole is equal to or less than 300 Å.  
     
     
         9 . The fabricating method of a semiconductor device according to  claim 5 , wherein said lower layer wiring contains Al.