Process for producing semiconductor integrated circuit device and semiconductor integrated circuit device

Abstract

In order to provide a light oxidation process technique for use in a CMOS LSI employing a polymetal gate structure and a dual gate structure, so that both oxidation of a refractory metal film constituting a part of a gate electrode and diffusion of boron contained in a p-type polycrystalline silicon film constituting a part of the gate electrode can be prevented, a mixed gas containing a hydrogen gas and steam synthesized from an oxygen gas and a hydrogen gas is supplied to a major surface of a semiconductor wafer A 1 , and a heat treatment for improving a profile of a gate insulating film that has been cut by etching under an edge part of the gate electrode is conducted under a low thermal load condition in that the refractor metal film is substantially not oxidized, and boron contained in a p-type polycrystalline silicon film constituting a part of the gate electrode is not diffused to the semiconductor substrate through the gate oxide film.

What is claimed is:  
     
         1 . A process for producing a semiconductor integrated circuit device, comprising the steps of: 
 (a) forming a silicon-containing electrode film of the semiconductor integrated circuit device, over a gate insulating film including silicon oxide, formed over a silicon surface portion of a major surface of a semiconductor wafer;    (b) forming a refractory metal film including tungsten or molybdenum as its main component over said silicon-containing electrode film;    (c) forming a gate electrode by patterning said silicon-containing electrode film and said refractory metal film; and    (d) after said step (c), subjecting said silicon surface portion and said silicon-containing electrode film to a thermal oxidation treatment in a mixed gas atmosphere containing a hydrogen gas and steam, wherein the mixed gas atmosphere is formed by diluting the steam, synthesized from the hydrogen and oxygen gases with the use of catalyst, with a gas including hydrogen gas.    
     
     
         2 . A process for producing a semiconductor integrated circuit device as claimed in  claim 1 , wherein a barrier layer including nitride of tungsten is formed between said silicon-containing electrode film and said refractory metal film.  
     
     
         3 . A process for producing a semiconductor integrated circuit device as claimed in  claim 2 , wherein said thermal oxidation treatment in said step (d) is conducted under a condition wherein said refractory metal film and said barrier layer are not oxidized.  
     
     
         4 . A process for producing a semiconductor integrated circuit device as claimed in  claim 1 , wherein said gate insulating film contains a silicon oxynitride film.  
     
     
         5 . A process for producing a semiconductor integrated circuit device as claimed in  claim 1 , including the further step of synthesizing the steam from hydrogen and oxygen gases with the use of the catalyst, with the steam synthesized being diluted by adding to the synthesized steam a gas including hydrogen gas to form said mixed gas atmosphere.  
     
     
         6 . A process for producing a semiconductor integrated circuit device as claimed in  claim 1 , wherein temperature of the thermal oxidation treatment of step (d) is in a range of 650 to 900 degrees Centigrade.  
     
     
         7 . A process for producing a semiconductor integrated circuit device as claimed in  claim 1 , wherein temperature of the thermal oxidation treatment of step (d) is in a range of 750 to 900 degrees Centigrade.  
     
     
         8 . A process for producing a semiconductor integrated circuit device as claimed in  claim 1 , wherein said mixed gas atmosphere contains 5-30% moisture as a percentage of moisture partial pressure in the whole atmospheric pressure.  
     
     
         9 . A process for producing a semiconductor integrated circuit device as claimed in  claim 1 , wherein said mixed gas atmosphere contains 8-25% moisture as a percentage of moisture partial pressure in the whole atmospheric pressure.  
     
     
         10 . A process for producing a semiconductor integrated circuit device, comprising the steps of: 
 (a) forming a silicon-containing electrode film of the semiconductor integrated circuit device, over a gate insulating film containing silicon oxide, formed over a silicon surface portion of a major surface of a semiconductor wafer;    (b) forming a refractory metal film over said silicon-containing electrode film;    (c) forming a gate electrode by patterning said silicon-containing electrode film and said refractory metal film; and    (d) after said step (c), subjecting said silicon surface portion and said silicon-containing electrode film to a thermal oxidation treatment in a mixed gas atmosphere containing a hydrogen gas and steam, wherein the mixed gas atmosphere has been formed by diluting the steam, synthesized from hydrogen and oxygen gases with the use of catalyst, with a gas including hydrogen gas.    
     
     
         11 . A process for producing a semiconductor integrated circuit device as claimed in  claim 10 , wherein a barrier layer is formed between said silicon-containing electrode film and said refractory metal film.  
     
     
         12 . A process for producing a semiconductor integrated circuit device as claimed in  claim 11 , wherein said thermal oxidation treatment in said step (d) is conducted under a condition wherein said refractory metal film and said barrier layer are not oxidized.  
     
     
         13 . A process for producing a semiconductor integrated circuit device as claimed in  claim 10 , including the further step of synthesizing the steam from hydrogen and oxygen gases with the use of the catalyst, with the steam synthesized being diluted by adding to the synthesized steam a gas including hydrogen to form said mixed gas atmosphere.  
     
     
         14 . A process for producing a semiconductor integrated circuit device as claimed in  claim 10 , wherein temperature of the thermal oxidation treatment of step (d) is in a range of 650 to 900 degrees Centigrade.  
     
     
         15 . A process for producing a semiconductor integrated circuit device as claimed in  claim 10 , wherein temperature of the thermal oxidation treatment of step (d) is in a range of 750 to 900 degrees Centigrade.  
     
     
         16 . A process for producing a semiconductor integrated circuit device as claimed in  claim 10 , wherein said mixed gas atmosphere contains 5-30% moisture as a percentage of moisture partial pressure in the whole atmospheric pressure.  
     
     
         17 . A process for producing a semiconductor integrated circuit device as claimed in  claim 10 , wherein said mixed gas atmosphere contains 8-25% moisture as a percentage of moisture partial pressure in the whole atmospheric pressure.  
     
     
         18 . A process for producing a semiconductor integrated circuit device, comprising the steps of: 
 (a) forming a silicon-containing electrode film of the semiconductor integrated circuit device, over a silicon surface portion of a major surface of a semiconductor wafer;    (b) forming a refractory metal film over said silicon-containing electrode film;    (c) forming a gate electrode by patterning said silicon-containing electrode film and said refractory metal film; and    (d) after said step (c), subjecting said silicon surface portion and said silicon-containing electrode film to a thermal oxidation treatment in a mixed gas atmosphere containing a hydrogen gas and steam, wherein the mixed gas atmosphere has been formed by diluting the steam with a gas including hydrogen gas.    
     
     
         19 . A process for producing a semiconductor integrated circuit device as claimed in  claim 18 , wherein said thermal oxidation treatment in said step (d) is conducted under a condition wherein said refractory metal film is not oxidized.  
     
     
         20 . A process for producing a semiconductor integrated circuit device as claimed in  claim 18 , including the further step of synthesizing the steam from hydrogen and oxygen gases with the use of the catalyst, with the steam synthesized being diluted by adding to the synthesized steam a gas including hydrogen gas to form said mixed gas atmosphere.  
     
     
         21 . A process for producing a semiconductor integrated circuit device as claimed in  claim 18 , wherein temperature of the thermal oxidation treatment of step (d) is in a range of 650 to 900 degrees Centigrade.  
     
     
         22 . A process for producing a semiconductor integrated circuit device as claimed in  claim 18 , wherein said mixed gas atmosphere contains 5-30% moisture as a percentage of moisture partial pressure in the whole atmospheric pressure.  
     
     
         23 . A process for producing a semiconductor integrated circuit device, comprising the steps of: 
 (a) forming a silicon-containing electrode film of the semiconductor integrated circuit device over a gate insulating film including silicon oxide, formed over a silicon surface portion of a major surface of a semiconductor wafer;    (b) forming a refractory metal film including tungsten or molybdenum as its main component over said silicon-containing electrode film;    (c) forming a gate electrode by patterning said silicon-containing electrode film and said refractory metal film; and    (d) after said step (c), subjecting said silicon surface portion and said silicon-containing electrode film, doped with boron, to a thermal oxidation treatment in a mixed gas atmosphere containing a hydrogen gas and steam synthesized from an oxygen gas and a hydrogen gas with the use of catalyst, wherein the mixed gas atmosphere has been formed by diluting the steam with a gas including hydrogen gas.    
     
     
         24 . A process for producing a semiconductor integrated circuit device as claimed in  claim 23 , including the further step of synthesizing the steam from hydrogen and oxygen gases with the use of the catalyst, with the steam synthesized being diluted by adding to the synthesized steam a gas including hydrogen gas to form said mixed gas atmosphere.  
     
     
         25 . A process for producing a semiconductor integrated circuit device as claimed in  claim 23 , wherein temperature of the thermal oxidation treatment of step (d) is in a range of 650 to 900 degrees Centigrade.  
     
     
         26 . A process for producing a semiconductor integrated circuit device as claimed in  claim 23 , wherein said mixed gas atmosphere contains 5-30% moisture as a percentage of moisture partial pressure in the whole atmospheric pressure.  
     
     
         27 . A process for producing an integrated circuit device, comprising the steps of: 
 (a) forming a first electrode film region including silicon over an insulating film over a first major surface of a semiconductor wafer; and    (b) performing a thermal oxidation treatment to said first electrode film region in a mixed gas atmosphere containing a hydrogen gas and steam under a condition wherein a refractory metal region over said first major surface is not oxidized, and wherein the mixed gas atmosphere has been formed by diluting the steam, synthesized from hydrogen and oxygen gases with the use of catalyst, with a gas including hydrogen gas.    
     
     
         28 . A process for producing an integrated circuit device as claimed in  claim 27 , wherein said refractory metal region is formed over said first electrode film region.  
     
     
         29 . A process for producing an integrated circuit device as claimed in  claim 27 , wherein boron is implanted into the first electrode film region prior to step (b).  
     
     
         30 . A process for producing a semiconductor integrated circuit device as claimed in  claim 27 , including the further step of synthesizing the steam from hydrogen and oxygen gases with the use of the catalyst, with the steam synthesized being diluted by adding to the synthesized steam a gas including hydrogen gas to form said mixed gas atmosphere.  
     
     
         31 . A process for producing a semiconductor integrated circuit device as claimed in  claim 27 , wherein temperature of the thermal oxidation treatment of step (b) is in a range of 650 to 900 degrees Centigrade.  
     
     
         32 . A process for producing a semiconductor integrated circuit device as claimed in  claim 27 , wherein said mixed gas atmosphere contains 5-30% moisture as a percentage of moisture partial pressure in the whole atmosphere pressure.  
     
     
         33 . A process for producing an integrated circuit device as claimed in  claim 28 , wherein said mixed gas atmosphere also contains a nitrogen gas.