Semiconductor device and method for manufacturing the same

Abstract

In a semiconductor device that includes a barrier film, an electrode pad on the barrier film, and a solder ball in the electrode pad, the electrode pad is prevented from exfoliating from the barrier film by a side wall film separating the solder ball from a boundary between the barrier film and the electrode pad.

What is claimed:  
     
         1 . A method of manufacturing a semiconductor device comprising the step of: 
 forming a solder ball in contact with an electrode pad resting on a barrier film by limiting the solder ball to a region apart from an edge boundary of the electrode pad and the barrier film.    
     
     
         2 . A method of manufacturing a semiconductor device comprising the steps of: 
 forming an insulating layer on a wiring layer;    forming an opening in said insulating layer, said opening exposing an upper surface of said wiring layer;    forming a first conductive film on an inner surface of said opening and on said insulating layer;    forming a second conductive film on said first conductive film;    patterning said first and second conductive films to form a barrier film on said wiring layer and an electrode pad on said barrier film;    forming a side wall film covering a boundary between said barrier film and said electrode pad on patterned edges of said barrier film and said electrode pad, and;    forming a solder ball on said electrode pad.    
     
     
         3 . The method as claimed in  claim 2 , wherein said side wall film is made by forming a side wall material film on an upper surface and a side surface of said electrode pad and a side surface of said barrier film, and etching back said side wall material film.  
     
     
         4 . The method as claimed in  claim 2 , wherein said side wall film is made by forming a TiW film on said electrode pad, patterning said TiW film, forming a polyimide film on said TiW film, and patterning said polyimde film and said TiW to form an opening which exposes a part of an upper surface of said electrode pad.  
     
     
         5 . The method as claimed in  claim 4 , wherein said solder ball is formed on said exposed part of said electrode pad.  
     
     
         6 . The method as claimed in  claim 2 , wherein said solder ball is good in wettability with said electrode pad and is poor in wettability with said barrier film and said side wall film.  
     
     
         7 . The method as claimed in  claim 2 , wherein said side wall film comprises the same material as said barrier film.  
     
     
         8 . The method as claimed in  claim 7 , wherein said material is TiW.  
     
     
         9 . The method as claimed in  claim 2 , wherein said solder ball comprises Sn, said electrode pad comprises Cu, and said barrier film comprises Ti.  
     
     
         10 . The method as claimed in  claim 2 , wherein said side wall film comprises a TiW film and a polyimide film.  
     
     
         11 . The method as claimed in  claim 2 , wherein said insulating layer comprises a SiO2 film, a SiON film and a polyimide film.  
     
     
         12 . The method as claimed in  claim 2 , wherein said side wall film is made by forming a first layer on said second conductive film, patterning said first layer before said patterning said first and second conductive films, forming a second layer on said first layer after said patterning said first and second conductive films, and patterning said second and first layer to form an opening which exposes a part of said electrode pad.  
     
     
         13 . A method of manufacturing a semiconductor device comprising: 
 forming a barrier film, which has an upper surface and a peripheral edge defining an outer shape of said barrier film;    forming an electrode pad on said upper surface of said barrier film, said electrode having an upper surface and a peripheral edge defining an outer shape of said electrode pad, said upper surface of said electrode pad having a center portion and a peripheral portion surrounding said center portion;    forming a first side wall film on said peripheral portion of said upper surface of said electrode pad;    forming a second side wall film along said peripheral edges of said barrier film and electrode pad, said second side wall film extending over said first side wall film, said first side wall film enhancing an adhesion between said second side wall film and said peripheral portion of said upper surface of said electrode pad; and    forming a solder ball on said center portion of said upper surface of said electrode pad, said solder ball being separated from said peripheral edges of said barrier film and said electrode pad by said side wall.    
     
     
         14 . The method as claimed in  claim 13 , further comprising: 
 forming a wiring layer;    forming an insulating layer on said wiring layer;    selectively forming an opening in said insulating layer to expose a part of said wiring layer;    wherein said barrier film is in contact with said part of said wiring layer and extends over said insulating layer.    
     
     
         15 . The method as claimed in  claim 13 , wherein said first side wall film comprises the same material as said barrier film.  
     
     
         16 . The method as claimed in  claim 15 , wherein said material is TiW.  
     
     
         17 . The method as claimed in  claim 13 , wherein said first side wall film comprises a TiW film and said second side wall film comprises a polyimide film.  
     
     
         18 . The method as claimed in  claim 13 , wherein said solder ball comprises Sn, said electrode pad comprises Cu, and said barrier film comprises Ti.