Semiconductor device and method for fabricating the same

Abstract

A semiconductor device includes a semiconductor substrate, an insulating film having one portion below a surface of the semiconductor substrate and the other portion above the surface of the semiconductor substrate a first region, and a semiconductor layer formed on the semiconductor substrate in a second region to the same thickness as the insulating film, which improves an operation speed even at a low voltage.

What is claimed is:  
     
         1 . A method for fabricating a semiconductor device, the method comprising: 
 oxidizing a substrate to form an insulating film having at least one gap where the substrate is exposed; and    forming a semiconductor layer on the substrate at one of the at least one gap in the insulating film, a height of the semiconductor layer being equal to a height of the insulating film.