Semiconductor device having fins FET and manufacturing method thereof

Abstract

A line-form insulator is formed on a substrate and then the substrate is etched with the insulator used as a mask to form first trenches on both sides of the insulator. Side wall insulators are formed on the side walls of the first trenches, the substrate is etched with the insulator and side wall insulators used as a mask to form second trenches in the bottom of the first trenches. After, the substrate is oxidized with the insulator and side wall insulators used as an anti-oxidation mask to cause oxide regions formed on the adjacent side walls of the second trenches lying on both sides of the substrate to make contact with each other and the insulator and side wall insulators are removed. Then, a fin FET having a semiconductor region as a line-form fin is formed in the substrate.

1 - 11 . (canceled) 
     
     
         12 . A semiconductor device comprising:
 a silicon oxide film formed on a bulk silicon substrate;   a line-form fin formed on the silicon oxide film; and   planar regions which are parts of the bulk silicon substrate and connected to both ends of the line-form fin in an extending direction,
 a width thereof in a direction perpendicular to the extending direction being larger than that of the line-form fin, and 
 a height of an upper surface thereof being set equal to height of an upper surface of the line-form fin. 
   
     
     
         13 . The semiconductor device according to  claim 12 , further comprising a first gate oxide film formed on the planar regions, and a first gate electrode formed on the first gate oxide film. 
     
     
         14 . The semiconductor device according to  claim 12 , further comprising an element isolation insulating film formed on the silicon oxide film between the planar region and the line-form fin. 
     
     
         15 . The semiconductor device according to  claim 14 , wherein height of a surface of the element isolation insulating film is set substantially equal to the height of the surface of the line-form fin. 
     
     
         16 . The semiconductor device according to  claim 12 , wherein a cross section of a portion of the planar region which is adjacent to the element isolation insulating film is formed in a rounded form. 
     
     
         17 . The semiconductor device according to  claim 12 , further comprising a second gate oxide film formed on an entire surface of the line-form fin, and a second gate electrode formed on the second gate oxide film. 
     
     
         18 . The semiconductor device according to  claim 12 , wherein a cross section of the line-form fin is formed in a rounded form.