Element fabrication substrate

Abstract

A substrate used for fabricating devices thereon includes an insulating film, and a monocrystal Ge thin layer formed on the insulating film in contact therewith, the monocrystal Ge thin layer having a thickness not more than 6 nm. The monocrystal Ge thin layer has a thickness not less than 2 nm and a compressive strain.

1 . A substrate used for fabricating a device thereon, comprising: 
 an insulating film; and    a monocrystal Ge thin layer formed on the insulating film in contact therewith, the layer having a thickness not more than 6 nm.    
     
     
         2 . The substrate according to  claim 1 , wherein the Ge thin layer has a compressive strain.  
     
     
         3 . The substrate according to  claim 1 , wherein the Ge thin layer has a thickness not less than 2 nm and a compressive strain.  
     
     
         4 . The substrate according to  claim 1 , wherein the monocrystal Ge thin layer is made of Si 1-x Ge x  formed on the insulating film.  
     
     
         5 . The substrate according to  claim 1 , which includes a Si oxide film formed on the monocrystal Ge thin layer by oxidation.  
     
     
         6 . The substrate according to  claim 1 , wherein the monocrystal Ge thin layer contains Ge composition not less than 60%.  
     
     
         7 . A semiconductor device comprising; 
 an insulating film;    a monocrystal Ge thin layer formed on the insulating film and having a compressive strain and a thickness not more than 6 nm and not less than 2 nm; and    a field effect transistor using the Ge thin layer as a channel.    
     
     
         8 . The semiconductor device according to  claim 7 , wherein the monocrystal Ge thin layer is made of Si 1-x Ge x  formed on the insulating film.  
     
     
         9 . The semiconductor device according to  claim 7 , which includes a Si oxide film formed on the monocrystal Ge thin layer.  
     
     
         10 . The semiconductor device according to  claim 7 , wherein the monocrystal Ge thin layer contains Ge composition not less than 60%.  
     
     
         11 . A method of manufacturing a substrate used for fabricating a device thereon, comprising: 
 forming a monocrystal SiGe layer on a monocrystal Si layer formed on an insulating film; and    heating the monocrystal Si layer and the monocrystal SiGe layer to oxidize them for forming a Si oxide film on the monocrystal SiGe layer, and to transform the monocrystal SiGe layer to a monocrystal Ge thin layer having a thickness not more than 6 nm.    
     
     
         12 . The method according to  claim 11 , wherein the monocrystal SiGe layer contains Ge composition not less than 60%, and the heating includes heating the monocrystal Si layer and the monocrystal SiGe layer at a temperature not more than a melting point of the monocrystal SiGe layer, with setting a heating temperature to a temperature exceeding 1000° C. at a time of oxidizing at first, and setting at a temperature not more than 900° C. at last while decreasing the heating temperature gradually, to form the monocrystal Ge thin layer having a compressive strain in a thickness not less than 4 nm.  
     
     
         13 . The method according to  claim 11 , including setting the oxidization temperature at a temperature not more than 850° C. to form the monocrystal Ge thin layer having a compressive strain in a thickness not less than 2 nm.  
     
     
         14 . The method according to  claim 11 , wherein the monocrystal Ge thin layer is made of Si 1-x Ge x  formed on the insulating film by crystal growth.  
     
     
         15 . The method according to  claim 11 , wherein Ge composition in the monocrystal SiGe layer before heat treatment is set to 15%.