Semiconductor integrated circuit device and process for manufacturing the same

Abstract

A semiconductor integrated circuit device comprises a plurality of holes in an interlayer insulating film beneath a bonding pad wherein a plug is buried in the respective holes and is made of the same conductive film (W/TiN/Ti) as a plug in a through-hole. Any wire as a second layer is not formed in a lower region of the bonding pad. The plug buried in the holes is connected only to the upper boding pad and is not connected to a lower wire.

What is claimed is:  
     
         1 . A semiconductor integrated circuit device of the type which comprises a plurality of wiring layers formed on a semiconductor substrate through an interlayer insulating film, and a bonding pad formed at an upper wiring layer, further comprising a first interlayer insulating film provided beneath said bonding pad formed, and a first plug formed in said first interlayer insulating film in such a way that a first conductive film is buried in a hole formed in said first interlayer insulating film wherein any wire connected to said first plug is not formed in a wiring layer beneath said first plug.  
     
     
         2 . A semiconductor integrated circuit device according to    claim 1   , wherein a wire is formed in a wiring layer lower than the wiring layer beneath said first plug.  
     
     
         3 . A semiconductor integrated circuit device according to    claim 1   , wherein any wire is not formed in either of the wiring layers in a lower region of said bonding pad.  
     
     
         4 . A semiconductor integrated circuit device according to    claim 1   , wherein said first interlayer insulating film of an element-forming region has a first through-hole, in which a second plug is buried for electric connection between a wire formed in the upper wiring layer and a wire formed in a lower wiring layer, and said first through-hole has a diameter substantially equal to that of said hole.  
     
     
         5 . A semiconductor integrated circuit device according to    claim 1   , wherein said first interlayer insulating film of an element-forming region has a first through-hole, in which a second plug is buried for electric connection between a wire formed in the upper wiring layer and a wire formed in a lower wiring layer, and said hole has a depth greater than said first through-hole.  
     
     
         6 . A semiconductor integrated circuit device according to    claim 1   , wherein said first conductive film buried in said hole contains a refractory metal film as its main component, and a barrier metal film is formed at the interface between said refractory metal film and the inner walls of said hole.  
     
     
         7 . A semiconductor integrated circuit device according to    claim 1   , wherein said bonding pad and said first plug are integrally formed.  
     
     
         8 . A semiconductor integrated circuit device according to    claim 1   , wherein said bonding pad has a length of 80 μm or below at one side thereof.  
     
     
         9 . A semiconductor integrated circuit device of the type which comprises a plurality of wiring layers formed on a semiconductor substrate through an interlayer insulating film, a bonding pad formed at an upper wiring layer and connected to a wire, further comprising a first interlayer insulating film provided at a lower region of the wire, and a first plug formed in said first interlayer insulating film in such a way that a first conductive film is buried in a hole formed in said first interlayer insulating film wherein any wire is not formed in a wiring layer below the first plug.  
     
     
         10 . A semiconductor integrated circuit device of the type which comprises a plurality of wiring layers formed on a semiconductor substrate through an interlayer insulating film, and a bonding pad formed at an uppermost wiring layer, further comprising a first interlayer insulating film provided beneath the bonding pad, a first plug formed in said first interlayer insulating film in such a way that a first conductive film is buried in a hole formed in said first interlayer insulating film, and a wire formed in a wiring layer beneath said first plug and made of a third conductive film whose hardness is higher than that of a second conductive film constituting an uppermost wire.  
     
     
         11 . A semiconductor integrated circuit device according to    claim 10   , wherein said third conductive film contains copper as its main component.  
     
     
         12 . A semiconductor integrated circuit device according to    claim 1   , wherein a wire of the wiring layer beneath said first plug is formed as not to be connected to said first plug in the lower region of said bonding pad.  
     
     
         13 . A method for manufacturing a semiconductor integrated circuit device comprising the steps of: 
 (a) forming a wire in an element-forming region on a semiconductor substrate and further forming an interlayer insulating film over said wire;    (b) etching the first interlayer insulating film in the element-forming region to forma first through-hole reaching said wire, and etching the first interlayer insulating film in a bonding pad-forming region to form a hole;    (c) forming a barrier metal film on the first interlayer insulating film including the inner surfaces of said hole and the inner surfaces of said first through-hole and forming a first conductive film containing as its main component a refractory metal film on the upper portion of the barrier metal film so that said first conductive film is buried in the hole and the first through-hole;    (d) removing said first conductive film from the upper portion of the first interlayer insulating film by etching to form a first plug constituted of said barrier metal film and said first conductive film in the hole and also a second plug constituted of said barrier metal film and said first conductive film in said first through-hole; and    (e) etching a second conductive film formed on the upper portion of said first interlayer insulating film so that an uppermost wire is formed on said first interlayer insulating film in the element-forming region and forming a bonding pad on said first interlayer insulating film in the bonding pad-forming region.    
     
     
         14 . A method for manufacturing a semiconductor integrated circuit device according to    claim 13   , further comprising, after the step (e), the steps of bonding a first wire on said bonding pad and bonding a second wire on said first wire.  
     
     
         15 . A method for manufacturing a semiconductor integrated circuit device according to    claim 13   , wherein said barrier metal film is made of a multi-layered film of a TiN film formed on a Ti film, said first conductive film includes a W film, and the etching of said first conductive film is carried out in an atmosphere of a gas containing fluorine.