Semiconductor device and manufacturing method of semiconductor device

Abstract

In one aspect of the present invention, a semiconductor device may include a semiconductor substrate; an element isolation region provided in the semiconductor substrate and having an oxide layer and an oxidant-diffusion prevention layer provided on the oxide layer; a gate dielectric film provided on the semiconductor substrate and the oxidant-diffusion prevention layer; and a gate electrode provided on the gate dielectric film.

1 . A method of manufacturing a semiconductor device, comprising:
 forming an element isolation region made of an oxide in a semiconductor substrate;   forming an oxidant-diffusion prevention layer by doping an upper portion of the element isolation region with an impurity;   forming a gate dielectric film on the semiconductor substrate and the oxidant-diffusion prevention layer; and   forming a gate electrode on the gate dielectric film.   
     
     
         2 . The method of manufacturing a semiconductor device according to  claim 1 , wherein the element isolation region is doped with the impurity to a depth lower than an upper surface of the semiconductor substrate.