Method of treating semiconductor film and method of fabricating semiconductor device

Abstract

A method of fabricating a semiconductor device includes the steps of forming an amorphous semiconductor film on a substrate, oxidizing the surface of the amorphous semiconductor film in an atmosphere containing water vapor and oxygen, and removing an oxide film which is formed on the surface of the semiconductor film.

What is claimed is:  
     
         1 . A method of treating a semiconductor film by oxidizing a surface of said semiconductor in an atmosphere containing water vapor.  
     
     
         2 . The method of treating a semiconductor film in accordance with  claim 1 , wherein said surface of said semiconductor film is oxidized in an atmosphere containing water vapor and oxygen.  
     
     
         3 . The method of treating a semiconductor film in accordance with  claim 1 , wherein said surface of said semiconductor film is oxidized in an atmosphere containing water vapor, so that impurity concentration in said semiconductor film is reduced.  
     
     
         4 . The method of treating a semiconductor film in accordance with  claim 1 , wherein said surface of said semiconductor film is oxidized in an atmosphere containing water vapor and oxygen, so that impurity concentration in said semiconductor film is reduced.  
     
     
         5 . The method of treating a semiconductor film in accordance with  claim 1 , wherein said semiconductor film is oxidized by a heat treatment.  
     
     
         6 . The method of treating a semiconductor film in accordance with  claim 1 , wherein said semiconductor film is amorphous.  
     
     
         7 . The method of treating a semiconductor film in accordance with  claim 6 , wherein said semiconductor film is oxidized by a heat treatment, so that said amorphous semiconductor film is crystallized by said heat treatment.  
     
     
         8 . The method of treating a semiconductor film in accordance with  claim 7 , wherein said amorphous semiconductor film is crystallized by solid-phase epitaxy or melt recrystallization.  
     
     
         9 . The method of treating a semiconductor film in accordance with  claim 1 , wherein said semiconductor film is a silicon film.  
     
     
         10 . A method of fabricating a semiconductor device, comprising the steps of: 
 forming an amorphous semiconductor film on a substrate;    oxidizing a surface of said amorphous semiconductor film in an atmosphere containing water vapor; and    removing an oxide film being formed on said surface of said semiconductor film.    
     
     
         11 . The method of fabricating a semiconductor device in accordance with  claim 10 , wherein said oxidation step comprises a step of oxidizing said surface of said amorphous semiconductor film in an atmosphere containing water vapor and oxygen.  
     
     
         12 . The method of fabricating a semiconductor device in accordance with  claim 10 , wherein said oxidation step comprises a step of heat treating said amorphous semiconductor film in an atmosphere containing water vapor thereby crystallizing said amorphous semiconductor film and oxidizing a surface thereof.  
     
     
         13 . The method of fabricating a semiconductor device in accordance with  claim 10 , wherein said oxidation step comprises a step of heat treating said amorphous semiconductor film in an atmosphere containing water vapor and oxygen thereby crystallizing said amorphous semiconductor film and oxidizing a surface thereof.  
     
     
         14 . The method of fabricating a semiconductor device in accordance with  claim 13 , wherein said amorphous semiconductor film is crystallized by solid-phase epitaxy or melt recrystallization.  
     
     
         15 . The method of fabricating a semiconductor device in accordance with  claim 10 , wherein said oxidation step comprises a step of performing a heat treatment in an atmosphere containing water vapor at a temperature causing no crystallization of said amorphous semiconductor film, thereby oxidizing a surface of said amorphous semiconductor film.  
     
     
         16 . The method of fabricating a semiconductor device in accordance with  claim 10 , wherein said oxidation step comprises a step of performing a heat treatment in an atmosphere containing water vapor and oxygen at a temperature causing no crystallization of said amorphous semiconductor film, thereby oxidizing a surface of said amorphous semiconductor film.  
     
     
         17 . The method of fabricating a semiconductor device in accordance with  claim 16 , further comprising a step of heat treating and crystallizing said amorphous semiconductor film after removal of said oxide film formed through said oxidation step.  
     
     
         18 . The method of fabricating a semiconductor device in accordance with  claim 17 , wherein said amorphous semiconductor film is heat treated by solid-phase epitaxy or melt recrystallization.  
     
     
         19 . The method of fabricating a semiconductor device in accordance with  claim 10 , wherein said semiconductor film is a silicon film.  
     
     
         20 . A thin film transistor employing a semiconductor film being fabricated by the method in accordance with claim as an active layer.  
     
     
         21 . A liquid crystal display employing the thin film transistor in accordance with  claim 20  as a pixel driving element.  
     
     
         22 . A driver-integrated liquid crystal display comprising a pixel part and a peripheral driving circuit part both of which are formed on the same substrate, said driver-integrated liquid crystal display employing the thin film transistors in accordance with  claim 20  as driving elements for said pixel part and said peripheral driving circuit part.  
     
     
         23 . A photovoltaic device employing a semiconductor layer being fabricated by the method in accordance with  claim 10  as a photovoltaic transmittance layer.  
     
     
         24 . A method of fabricating a thin film transistor having a semiconductor film as an active layer, said semiconductor film being obtained by forming an amorphous semiconductor layer on a substrate and heat treating said amorphous semiconductor film thereby crystallizing said amorphous semiconductor film, and said method comprising the steps of: 
 performing a heat treatment in an atmosphere containing water vapor thereby crystallizing said amorphous semiconductor layer and oxidizing a surface thereof; and    removing an oxide film from said surface of said semiconductor film.    
     
     
         25 . The method of fabricating a thin film transistor in accordance with  claim 24 , wherein said oxidation step comprises a step of performing a heat treatment in an atmosphere containing water vapor and oxygen thereby crystallizing said amorphous semiconductor film and oxidizing a surface thereof.  
     
     
         26 . A method of fabricating a photovoltaic device having a semiconductor film as a photovoltaic transmittance layer, said semiconductor film being obtained by forming an amorphous semiconductor film on a substrate and heat treating said amorphous semiconductor film thereby crystallizing said amorphous semiconductor film, and said method comprising the steps of: 
 heat treating said amorphous semiconductor film in an atmosphere containing water vapor thereby oxidizing a surface thereof; and    removing an oxide film from said surface of said semiconductor film.    
     
     
         27 . The method of fabricating a photovoltaic device in accordance with  claim 26 , wherein said oxidation step comprises a step of heat treating said amorphous semiconductor film in an atmosphere containing water vapor thereby crystallizing said amorphous semiconductor film and oxidizing a surface thereof.  
     
     
         28 . The method of fabricating a photovoltaic device in accordance with  claim 26 , wherein said oxidation step comprises a step of performing a heat treatment in an atmosphere containing water vapor at a temperature causing no crystallization of said amorphous semiconductor film thereby oxidizing a surface thereof.  
     
     
         29 . The method of fabricating a photovoltaic device in accordance with  claim 26 , wherein said amorphous semiconductor film is heat treated in an atmosphere containing water vapor and oxygen.  
     
     
         30 . A method of fabricating a semiconductor device by forming a polycrystalline silicon film by supplying external energy in an atmosphere containing gas containing at least oxygen.  
     
     
         31 . The method of fabricating a semiconductor device in accordance with  claim 30 , wherein said external energy is supplied by solid-phase epitaxy or melt recrystallization.  
     
     
         32 . The method of fabricating a semiconductor device in accordance with  claim 30 , comprising the steps of: 
 forming an amorphous silicon film on a semiconductor substrate or an insulating substrate; and    making solid-phase epitaxy or melt recrystallization of said amorphous silicon film in an atmosphere at least containing gas containing oxygen thereby forming a polycrystalline silicon film.    
     
     
         33 . The method of fabricating a semiconductor device in accordance with  claim 32 , further comprising a step of employing said polycrystalline silicon film as an active layer.