Semiconductor integrated circuit device and production method thereof

Abstract

A refresh characteristic of a DRAM memory cell is improved and the performance of a MISFET formed in the periphery thereof and constituting a logic circuit is improved. Each gate electrode in a memory cell area is formed of p type polycrystalline silicon, and a cap insulating film on each gate electrode and a sidewall film on the sidewall thereof are formed of a silicon oxide film. A polycrystalline silicon film formed on the gate electrodes and between the gate electrodes is polished by a CMP method, and thereby contact electrodes are formed. Also, sidewall films each composed of a laminated film of the silicon oxide film and the polycrystalline silicon film are formed on the sidewall of the gate electrodes in the logic circuit area, and these films are used as a mask to form semiconductor areas. As a result, it is possible to reduce the boron penetration and form contact electrodes in a self-alignment manner. In addition, the performance of the MISFET constituting the logic circuit can be improved.

1 . A production method of a semiconductor integrated circuit device having: a memory cell composed of a memory cell selecting n channel MISFET and a capacitor which are formed in a memory cell forming area of a semiconductor substrate; and an n channel MISFET and a p channel MISFET which are formed in a peripheral circuit forming area, said production method comprising: 
 (a) a step of forming a gate insulating film on said semiconductor substrate;    (b) a gate electrode forming step of forming a silicon film and an insulating film on said gate insulating film, and forming, by patterning, gate electrodes of a memory cell selecting n channel MISFET, an n channel MISFET, and a p channel MISFET and insulating films on the upper portions thereof, wherein said gate electrode forming step comprises the steps of: introducing a p type impurity into a silicon film constituting the gate electrode of said memory cell selecting n channel MISFET and the gate electrode of said p channel MISFET; and introducing an n type impurity into a silicon film constituting the gate electrode of said n channel MISFET;    (c) a step of sequentially depositing a first film and a second film on said semiconductor substrate, and leaving, by performing an anisotropic etching, the first and second films on a sidewall of the gate electrode in said peripheral circuit forming area, and filling spaces between said gate electrodes in said memory cell forming area, with said first and second films; and    (d) a step of using said first and second films as a mask to implant an impurity into both sides of each of the gate electrodes of said n channel MISFET and said p channel MISFET and thereby form a semiconductor area.    
   
   
       2 . The production method according to  claim 1 , further comprising: 
 a step of removing said second film in the memory cell forming area and thereafter removing said first film on said semiconductor substrate; and    a step of filling, with a conductive film, a space between the gate electrodes of said memory cell selecting n channel MISFET and thereby form a contact electrode.    
   
   
       3 . The production method according to  claim 2 , 
 wherein said contact electrode is formed by the steps of depositing said conductive film on the gate electrodes and between the gate electrodes, and polishing said conductive film on said gate electrodes until the first film on said gate electrode is exposed.    
   
   
       4 . A production method of a semiconductor integrated circuit device having: a memory cell composed of a memory cell selecting n channel MISFET and a capacitor which are formed in a memory cell forming area of a semiconductor substrate; and an n channel MISFET and a p channel MISFET which are formed in a peripheral circuit forming area, said production method comprising: 
 (a) a step of forming a gate insulating film on said semiconductor substrate;    (b) a gate electrode forming step of forming a silicon film and an insulating film on said gate insulating film, and forming, by patterning, gate electrodes of a memory cell selecting n channel MISFET, an n channel MISFET, and a p channel MISFET and insulating films on the upper portions thereof, wherein said gate electrode forming step comprises the steps of: introducing a p type impurity into a silicon film constituting the gate electrode of said memory cell selecting n channel MISFET and the gate electrode of said p channel MISFET; and introducing an n type impurity into a silicon film constituting the gate electrode of said n channel MISFET;    (c) a step of using, as a mask, the gate electrode of said memory cell selecting n channel MISFET and the insulating film on the upper portion thereof to implant an impurity into the both sides of said gate electrode and thereby form a first semiconductor area in the semiconductor substrate of the memory cell forming area;    (d) a step of sequentially depositing a first film and a second film on said semiconductor substrate, and leaving, by performing an anisotropic etching, the first and second films on a sidewall of the gate electrode in said peripheral circuit forming area, and filling spaces between said gate electrodes in said memory cell forming area, with said first and second films;    (e) a step of using, as a mask, said first and second films to implant an impurity into both sides of each of the gate electrodes of said n channel MISFET and said p channel MISFET and thereby form a second semiconductor area; and    (f) a step of using, as a mask, the gate electrodes of said n channel MISFET and p channel MISFET and the insulating films on the upper portions thereof to implant an impurity into both sides of each of said gate electrodes and thereby form a third semiconductor area having a impurity concentration lower than said second semiconductor area in the semiconductor substrate of the memory cell forming area.    
   
   
       5 . A production method of a semiconductor integrated circuit device having: a memory cell composed of a memory cell selecting n channel MISFET and a capacitor which are formed in a memory cell forming area of a semiconductor substrate; and an n channel MISFET and a p channel MISFET which are formed in a peripheral circuit forming area, said production method comprising: 
 (a) a step of forming a gate insulating film on said semiconductor substrate;    (b) a gate electrode forming step of forming a silicon film and an insulating film on said gate insulating film, and forming, by patterning, gate electrodes of a memory cell selecting n channel MISFET, an n channel MISFET, and a p channel MISFET and insulating films on the upper portions thereof, wherein said gate electrode forming step comprises the steps of: introducing a p type impurity into a silicon film constituting the gate electrode of said memory cell selecting n channel MISFET and the gate electrode of said p channel MISFET; and introducing an n type impurity into a silicon film constituting the gate electrode of said n channel MISFET;    (c) a step of depositing a first film on said semiconductor substrate, and removing said first film on said semiconductor substrate in the memory cell forming area;    (d) a step of depositing a second film on said first film and said semiconductor substrate, and leaving, by performing an anisotropic etching, the first and second films on a sidewall of said gate electrode in said peripheral circuit forming area, and filling spaces between said gate electrodes in said memory cell forming area and on said semiconductor substrate, with said second film; and    (e) a step of using, as a mask, said first and second films to implant an impurity into both sides of each of the gate electrodes of said n channel MISFET and said p channel MISFET and thereby form a semiconductor area.    
   
   
       6 . The production method according to  claim 1 , 
 wherein each of said insulating film and said first film is a film containing one of no hydrogen and little hydrogen.    
   
   
       7 . The production method according to  claim 1 , 
 wherein said first film is a silicon oxide film and said second film is a silicon film.    
   
   
       8 . The production method according to  claim 1 , 
 wherein said first film is a film containing one of no hydrogen and little hydrogen, and said first and second films are films whose etching selective ratios are different.    
   
   
       9 . The production method according to  claim 1 , 
 wherein said first film is a film containing one of no hydrogen and little hydrogen, and said first and second films are insulating films whose etching selective ratios are different.    
   
   
       10 . A production method of a semiconductor integrated circuit device having: a memory cell composed of a memory cell selecting n channel MISFET and a capacitor which are formed in a memory cell forming area of a semiconductor substrate; and an n channel MISFET and a p channel MISFET which are formed in a peripheral circuit forming area, said production method comprising: 
 (a) a step of forming a gate insulating film on said semiconductor substrate;    (b) a gate electrode forming step of forming a silicon film and an insulating film on said gate insulating film, and forming, by patterning, gate electrodes of a memory cell selecting n channel MISFET, an n channel MISFET, and a p channel MISFET and insulating films on the upper portions thereof, wherein said gate electrode forming step comprises the steps of: introducing a p type impurity into a silicon film constituting the gate electrode of said memory cell selecting n channel MISFET and the gate electrode of said p channel MISFET; and introducing an n type impurity into a silicon film constituting the gate electrode of said n channel MISFET;    (c) a step of depositing a first film on said semiconductor substrate, and removing said first film in the memory cell forming area;    (d) a step of depositing a second film on said semiconductor substrate;    (e) a step of performing an anisotropic etching relative to said first and second films in said peripheral circuit forming area, and thereby leaving the first and second films on a sidewall of the gate electrode in said peripheral circuit forming area; and    (f) a step of using said first and second films as a mask to implant an impurity into both sides of each of the gate electrodes of said n channel MISFET and said p channel MISFET and thereby form a semiconductor area.    
   
   
       11 . The production method according to  claim 10 , further comprising a step of forming said capacitor connected to the memory cell selecting n channel MISFET, wherein said step of forming said capacitor includes a step of forming capacitors made of metal, for a lower electrode and an upper electrode thereof.  
   
   
       12 . The production method according to  claim 11 , 
 wherein metal composing one of said lower electrode and said upper electrode is Ru.    
   
   
       13 . The production method according to  claim 1 , 
 wherein the arrangement of said memory cell is an open bit line arrangement.    
   
   
       14 - 22 . (canceled)