Semiconductor device and method for fabricating the same

Abstract

The semiconductor device comprises a semiconductor substrate 10 , a conducting film 20 formed on the semiconductor substrate 10 and including two conductor patterns adjacent to each other; an etching stopper film covering the upper surface of the conducting film 20 ; an insulation film 28 which includes a contact hole which reaches the semiconductor substrate 10 between the two conductor patterns and the an end of which is positioned on the etching stopper film 22 on the two conductor patterns; and a sidewall insulation film 32 formed on the side walls of the conducting film 20 and of the etching stopper film 22 in the contact hole. The fluctuation of a contact hole size due to disalignment of the lithography can be restrained, and in the lithography step of opening the contact hole, the photoresist can have a large openings size, which facilitate the lithography step.

1 : A method for fabricating a semiconductor device comprising: 
 a first conducting film forming step of forming on a base substrate a first conducting film including a plurality of conductor patterns adjacent to each other, and having a upper surface thereof covered with an etching stopper film;    a first insulation film forming step of forming a first insulation film buried between said a plurality of conductor patterns;    a contact hole forming steps of etching the first insulation film with the etching stopper film as a mask to form a contact hole which reaches the base substrate between the conductor patterns and an end of which is defined by the conductor patterns; and    a sidewall insulation film forming steps of forming a sidewall insulation film on side walls of the first conducting film and the etching stopper film in the contact hole.    
     
     
         2 : A method for fabricating a semiconductor device according to  claim 1 , wherein 
 in the contact hole forming step the first insulation film is etched with a photoresist having an opening extended over said a plurality of conductor patterns and the etching stopper film as a mask to form a plurality of the contact holes in the opening.    
     
     
         3 : A method for fabricating a semiconductor device according to  claim 1 , further comprising before the first conducting film forming step, 
 a device isolation film forming step of forming a device isolation film buried in the base substrate.    
     
     
         4 : A method for fabricating a semiconductor device according to  claim 2 , further comprising before the first conducting film form step, 
 a device isolation film forming step of forming a device isolation film buried in the base substrate.    
     
     
         5 : A method for fabricating a semiconductor device comprising: 
 a word line forming step of forming on a semiconductor substrate a plurality of word lines extended in a first direction of having upper surfaces thereof covered with an etching stopper film;    a first insulation film forming step of forming a first insulation film on the etching stopper film and the semiconductor substrate;    a contact hold forming step of forming in the first insulation film a contact hole which reaches the semiconductor substrate between the word lines, and an end of which is positioned on the etching stopper film on the word lines;    a sidewall insulation film forming step of forming a sidewall insulation film on side walls of the word lines and of the etching stopper film in the contact hole; and    a bit line forming step of forming on the first insulation film a plurality of bit lines extended in a second direction which intersects the first direction and connected to the semiconductor substrate through the contact hole.    
     
     
         6 : A method for fabricating a semiconductor device comprising: 
 a word line forming step of forming on a semiconductor substrate a plurality of word lines extended in a first direction of having upper surfaces thereof covered with an etching stopper film;    a first insulation film forming step of forming a first insulation film buried between the word lines;    a contact hole forming step of etching the first insulation film with the etching stopper film as a mask to form a contact hole which reaches the semiconductor substrate between the word lines and an end of which is defined by the word lines;    a sidewall insulation film forming step of forming a sidewall insulation film on side walls of the word lines and the etching stopper film in the contact hole; and    a bit line forming step of forming on the first insulation film a plurality of bit lines extended in a second direction which intersects the first direction and connected to the semiconductor substrate through the contact hole.    
     
     
         7 : A method for fabricating a semiconductor device comprising: 
 a word line forming step of forming on a semiconductor substrate a plurality of word lines extended in a first direction and having upper surfaces thereof covered with an etching stopper film;    a sidewall insulation film forming step of forming sidewall insulation film having etching characteristics substantially equal to those of the etching stopper film on side walls of the word lines and of the etching stopper film;    a first insulation film forming step of forming a first insulation film buried between the word lines with the sidewall insulation film formed on;    a contact hole forming step of etching the first insulation film with the etching stopper film and the sidewall insulation film as a mask to form a contact hole which reaches the semiconductor substrate between the word lines and an end of which is defined by the sidewall insulation film; and    a bit line forming step of forming on the first insulation film a plurality of bit lines extended in a second direction which intersects the first direction and connected to the semiconductor substrate through the contact hole.    
     
     
         8 : A method for fabricating the semiconductor device according to  claim 6 , wherein 
 in the contact hole forming step, the first insulation film is etched with a photoresist including an opening extended over the word lines, and the etching stopper film as a mask to form a plurality of the contact holes in the opening.    
     
     
         9 : A method for fabricating the semiconductor device according to  claim 7 , wherein 
 in the contact hole forming step, the first insulation film is etched with a photoresist including an opening extended over the word lines, and the etching stopper film as a mask to form a plurality of the contact holes in the opening.    
     
     
         10 : A method for fabricating the semiconductor device according to  claim 5 , further comprising before the bit line forming step, 
 a plug forming step of forming a plug buried in the contact hole.    
     
     
         11 : A method for fabricating the semiconductor device according to  claim 6 , further comprising before the bit line forming step, 
 a plug forming step of forming a plug buried in the contact hole.    
     
     
         12 : A method for fabricating the semiconductor device according to  claim 7 , further comprising before the bit line forming step, 
 a plug forming step of forming a plug buried in the contact hole.    
     
     
         13 : A method for fabricating a semiconductor device comprising: 
 a word line forming step of forming on a semiconductor substrate a plurality of word lines extended in a first direction;    a first insulation film forming step of forming a first insulation film on the semiconductor substrate with the work lines formed on;    a bit line forming step of forming on the first insulation film a plurality of bit lines extended in a second direction which intersects the first direction and having upper surfaces thereof covered with an etching stopper film;    a second insulation film forming step of forming a second insulation film on the etching stopper film and the first insulation film;    a contact hole forming step forming in the second insulation film a contact hole which is formed between the bit lines and an end of which is positioned on the etching stopper film on the bit lines;    a sidewall insulation film forming step of forming a sidewall insulation film on side walls of the bit lines and of the etching stopper film in the contact hole; and    a capacitor forming step of forming on the second insulation film a capacitor having one electrode connected to the semiconductor substrate through the contact hole.    
     
     
         14 : A method for fabricating a semiconductor device comprising: 
 a word line forming step of forming on a semiconductor substrate a plurality of word lines extended in a first direction;    a first insulation film forming step of forming a first insulation film on the semiconductor substrate with the word lines formed on;    a bit line forming step of forming on the first insulation film a plurality of bit lines extended in a second direction which intersects the first direction and having upper surface thereof covered with an etching stopper film;    a second insulation film forming step of forming a second insulation film buried between the bit lines;    a contact hole forming step of etching the second insulation film with the etching stopper film as a mask to form a contact hole which is formed on between the bit lines and an end of which is defined by the bit lines;    a sidewall insulation film forming step of forming a sidewall insulation film on side walls of the bit lines and of the etching stopper film in the contact hole; and    a capacitor forming step of forming on the second insulation film a capacitor having one electrode connected to the semiconductor substrate through the contact hole.    
     
     
         15 : A method for fabricating a semiconductor device according to  claim 13 , wherein 
 in contact hole forming step, the second insulation film is etched with a photoresist having a pattern which alternately covers a region between the word lines, and the etching stopper film as a mask to form a plurality of the contact holes.    
     
     
         16 : A method for fabricating a semiconductor device according to  claim 14 , wherein 
 in contact hole forming step, the second insulation film is etched with a photoresist having a pattern which alternately covers a region between the word lines, and the etching stopper film as a mask to form a plurality of the contact holes.    
     
     
         17 : A method for fabricating a semiconductor device according to  claim 13 , wherein 
 in the contact hole forming step, the first insulation film and the second insulation film are etched to form a contact hole which reaches the semiconductor substrate and an end of which is defined by the bit lines and the word lines.    
     
     
         18 : A method for fabricating a semiconductor device according to  claim 14 , wherein 
 in the contact hole forming step, the first insulation film and the second insulation film are etched to form a contact hole which reaches the semiconductor substrate and an end of which is defined by the bit lines and the word lines.    
     
     
         19 : A method for fabricating a semiconductor device according to  claim 13 , wherein 
 in the bit line forming step, the etching stopper film is formed of a conductor; and    in the capacitor forming step the etching stopper film is processed in the same pattern as said one electrode of the capacitor.    
     
     
         20 : A method for fabricating a semiconductor device according to  claim 14 , wherein 
 in the bit line forming step, the etching stopper film is formed of a conductor; and    in the capacitor forming step the etching stopper film is processed in the same pattern as said one electrode of the capacitor.