Insulating film and method of producing semiconductor device

Abstract

A silicon oxide film is formed to cover an island non-monocrystalline silicon region by plasma CVD using an organic silane having ethoxy groups (e.g., TEOS) and oxygen as raw materials, while hydrogen chloride or a chlorine-containing hydrocarbon (e.g., trichloroethylene) of a fluorine-containing gas is added to the plasma CVD atmosphere, preferably in an amount of from 0.01 to 1 mol % of the atmosphere so as to reduce the alkali elements from the silicon oxide film formed and to improve the reliability of the film. Prior to forming the silicon oxide film, the silicon region may be treated in a plasma atmosphere containing oxygen and hydrogen chloride or a chlorine-containing hydrocarbon. The silicon oxide film is obtained at low temperatures and this has high reliability usable as a gate-insulating film in a semiconductor device.

What is claimed is:  
     
         1 . A semiconductor device comprising: 
 an insulating film comprising silicon oxide on an insulating surface,    wherein the insulating film includes halogen at a concentration of 5×10 20  cm −3  or less and carbon at a concentration of 5×10 19  cm −3  or less which are detected by second ion mass spectroscopy.    
     
     
         2 . A device according to  claim 1 , wherein the halogen is chlorine.  
     
     
         3 . A device according to  claim 1 , wherein the halogen is fluorine.  
     
     
         4 . A device according to  claim 1 , 
 wherein the insulating film includes carbon at a concentration of 1×10 18  cm −3  or less which is detected by the second ion mass spectroscopy.    
     
     
         5 . A device according to  claim 1 , 
 wherein the insulating film includes halogen at a concentration of 1×10 17  cm −3  or more which is detected by the second ion mass spectroscopy.    
     
     
         6 . A device according to  claim 1 , 
 wherein the insulating film is a gate insulating film.    
     
     
         7 . A device according to  claim 1 , 
 wherein the insulating film is an insulating film in a thin film transistor.    
     
     
         8 . A device according to  claim 1 , 
 wherein the insulating film covers an even surface over a glass substrate.    
     
     
         9 . A device according to  claim 1 , 
 wherein the insulating film is formed by plasma chemical vapor deposition using an organic silane.    
     
     
         10 . A device according to  claim 9 , 
 wherein the organic silane comprises at least a material selected from the group consisting of Si(OC 2 H 5 ) 4 , Si 2 O(OC 2 H 5 ) 6 , Si 3 O 2 (OC 2 H 5 ) 8 , Si 4 O 3 (OC 2 H 5 ) 10  and Si 5 O 4 (OC 2 H 5 ) 12 .    
     
     
         11 . A semiconductor device comprising: 
 a crystalline semiconductor island on an insulating surface; and    an insulating film including silicon oxide to cover the crystalline semiconductor island,    wherein the insulating film includes halogen at a concentration of 5×10 20  cm −3  or less and carbon at a concentration of 5×10 19  cm −3  or less.    
     
     
         12 . A device according to  claim 11 , 
 wherein the concentrations of halogen and carbon are detected by secondary ion mass spectroscopy.    
     
     
         13 . A device according to  claim 11 , wherein the halogen is chlorine.  
     
     
         14 . A device according to  claim 11 , wherein the halogen is fluorine.  
     
     
         15 . A device according to  claim 11 , 
 wherein the insulating film includes carbon at a concentration of 1×10 18  cm −3  or less.    
     
     
         16 . A device according to  claim 11 , 
 wherein the insulating film includes halogen at a concentration of 1×10 17  cm −3  or more.    
     
     
         17 . A device according to  claim 11 , 
 wherein the insulating film is formed by plasma chemical vapor deposition using an organic silane.    
     
     
         18 . A device according to  claim 17 , 
 wherein the organic silane comprises at least a material selected from the group consisting of Si(OC 2 H 5 ) 4 , Si 2 O(OC 2 H 5 ) 6 , Si 3 O 2 (OC 2 H 5 ) 8 , Si 4 O 3 (OC 2 H 5 ) 10  and Si 5 O 4 (OC 2 H 5 ) 12 .    
     
     
         19 . A semiconductor device including at least a thin film transistor comprising: 
 a crystalline semiconductor island on an insulating surface;    a silicon oxide film over the crystalline semiconductor island; and    a conductive film including at least one of aluminum, titanium, and titanium nitride, said conductive film being formed on the silicon oxide film,    wherein the silicon oxide film includes halogen at a concentration of 5×10 20  cm −3  or less and carbon at a concentration of 5×10 19  cm −3  or less.    
     
     
         20 . A device according to  claim 19 , 
 wherein the concentrations of halogen and carbon are detected by secondary ion mass spectroscopy.    
     
     
         21 . A device according to  claim 19 , wherein the halogen is chlorine.  
     
     
         22 . A device according to  claim 19 , wherein the halogen is fluorine.  
     
     
         23 . A device according to  claim 19 , 
 wherein the silicon oxide film includes carbon at a concentration of 1×10 18  cm −3  or less.    
     
     
         24 . A device according to  claim 19 , 
 wherein the silicon oxide film includes halogen at a concentration of 1×10 17  cm −3  or more.    
     
     
         25 . A device according to  claim 19 , 
 wherein the silicon oxide film is formed by plasma chemical vapor deposition using an organic silane.    
     
     
         26 . A device according to  claim 17 , 
 wherein the organic silane comprises at least a material selected from the group consisting of Si(OC 2 H 5 ) 4 , Si 2 O(OC 2 H 5 ) 6 , Si 3 O 2 (OC 2 H 5 ) 8 , Si 4 O 3 (OC 2 H 5 ) 10  and Si 5 O 4 (OC 2 H 5 ) 12 .    
     
     
         27 . A semiconductor device including at least a thin film transistor comprising: 
 a crystalline semiconductor island on an insulating surface;    a gate insulating film including silicon oxide on the crystalline semiconductor island; and    a gate electrode on the gate insulating film,    wherein the gate insulating film includes halogen at a concentration of 5×10 20  cm −3  or less and carbon at a concentration of 5×10 19  cm −3  or less.    
     
     
         28 . A device according to  claim 27 , 
 wherein the concentrations of halogen and carbon are detected by secondary ion mass spectroscopy.    
     
     
         29 . A device according to  claim 27 , wherein the halogen is chlorine.  
     
     
         30 . A device according to  claim 27 , wherein the halogen is fluorine.  
     
     
         31 . A device according to  claim 27 , 
 wherein the gate insulating film includes carbon at a concentration of 1×10 18  cm −3  or less.    
     
     
         32 . A device according to  claim 27 , 
 wherein the gate insulating film includes halogen at a concentration of 1×10 17  cm −3  or more.    
     
     
         33 . A device according to  claim 27 , 
 wherein the gate insulating film is formed by plasma chemical vapor deposition using an organic silane.    
     
     
         34 . A device according to  claim 33 , 
 wherein the organic silane comprises at least a material selected from the group consisting of Si(OC 2 H 5 ) 4 , Si 2 O(OC 2 H 5 ) 6 , Si 3 O 2 (OC 2 H 5 ) 8 , Si 4 O 3 (OC 2 H 5 ) 10  and Si 5 O 4 (OC 2 H 5 ) 12 .