Semiconductor device and manufacturing method thereof

Abstract

An adhesion layer for causing a plug for electrically connecting a lower wiring and an upper wiring opposite to each other with an interlayer insulating film interposed therebetween to adhere to the interlayer insulating film is formed within a through hole for forming the plug, based on a predetermined aspect ratio represented by a ratio of a depth dimension of the through hole to a diameter dimension of the through hole.

What is claimed is:  
     
         1 . A semiconductor device comprising: 
 a lower wiring and an upper wiring opposite to each other via a through hole defined in an interlayer insulating film;    a plug for electrically connecting the lower wiring and the upper wiring to each other within the through hole; and    an adhesion layer for causing the plug to adhere to the interlayer insulating film within the through hole,    wherein the adhesion layer is formed by sputtering based on a predetermined aspect ratio indicated by a ratio of a depth dimension of the through hole to a diameter dimension thereof.    
     
     
         2 . The semiconductor device according to  claim 1 , wherein the adhesion layer lying within the through hole is formed only on a sidewall of the through hole.  
     
     
         3 . The semiconductor device according to  claim 1 , wherein a thickness dimension of the adhesion layer on the lower wiring is formed to a thickness dimension which causes gas having corrosion behavior to be penetrable.  
     
     
         4 . The semiconductor device according to  claim 1 , wherein each of the lower wiring and the upper wiring is a laminated structure wherein a cap metal layer is provided on an aluminum alloy layer.  
     
     
         5 . The semiconductor device according to  claim 4 , wherein each of the lower wiring and the upper wiring has a high melting-point metal layer provided below the aluminum alloy layer.  
     
     
         6 . The semiconductor device according to  claim 4 , wherein the aluminum alloy layer is an alloy made of aluminum and copper.  
     
     
         7 . The semiconductor device according to  claim 4 , wherein the cap metal layer is formed of a laminated layer of titanium nitride and titanium, or a layer made of titanium nitride alone.  
     
     
         8 . The semiconductor device according to  claim 5 , wherein the high melting-point metal layer is formed of a laminated layer of titanium nitride and titanium, or a layer made of titanium nitride alone.  
     
     
         9 . The semiconductor device according to  claim 1 , wherein a linear dimension of the lower wiring is formed long.  
     
     
         10 . The semiconductor device according to  claim 1 , wherein the lower wiring is a first wiring on a semiconductor substrate having a semiconductor element.  
     
     
         11 . The semiconductor device according to  claim 1 , wherein the lower wiring is a wiring held in a floating state of being not directly connected to the semiconductor substrate having the semiconductor element.  
     
     
         12 . The semiconductor device according to  claim 1 , wherein the plug is a tungsten plug.  
     
     
         13 . The semiconductor device according to  claim 1 , wherein the adhesion layer is formed using titanium nitride.  
     
     
         14 . The semiconductor device according to  claim 1 , wherein the adhesion layer is formed such that the relationship between a thickness dimension of a material deposited on the interlayer insulating film by said sputtering and the aspect ratio results in the fact that when the aspect ratio is over 2.5 and less than 3, the thickness dimension of the deposited material ranges from over 7.5 nm to under 10 nm, when the aspect ratio is over 3 and less than 3.5, the thickness dimension of the deposited material ranges from over 7.5 nm to under 20 nm, and when the aspect ratio is over 3.5 and less than 4, the thickness dimension of the deposited material ranges from over 7.5 nm to under 30 nm.  
     
     
         15 . The semiconductor device according to  claim 1 , wherein the adhesion layer is formed by sputtering having directivity, and sputtering is effected on an object to be sputtered from every direction at an incident angle of 5° or more.  
     
     
         16 . The semiconductor device according to  claim 15 , wherein the adhesion layer is formed such that the relationship between the aspect ratio and the incident angle results in the fact that the incident angle at the time that the aspect ratio is over 1 and less than 1.5, is 45° or more, the incident angle at the time that the aspect ratio is over 1.5 and less than 2, is 26° or more, and the incident angle at the time that the aspect ratio is over 2.5 and less than 3, is 18° or more.