Capacitor in semiconductor device having dual dielectric film structure and method for fabricating the same

Abstract

A capacitor in a semiconductor device having a dual dielectric film structure and a fabrication method therefor are disclosed. The capacitor comprises: a lower electrode formed on a semiconductor substrate, a dielectric film of a dual dielectric film structure composed of an Si 3 N 4 chloride-free thin film and a Ta 2 O 5 thin film, which is formed on the lower electrode, and an upper electrode formed on the dielectric film. Meanwhile, the method for fabricating the capacitor comprises the steps of: forming a lower electrode on a semiconductor substrate, forming a dielectric film of a dual dielectric film structure composed of an Si 3 N 4 thin film and a Ta 2 O 5 thin film on the lower electrode, and forming an upper electrode on the dielectric film.

1 . A capacitor in a semiconductor device having a dual dielectric film structure, the capacitor comprising: 
 a lower electrode formed on a semiconductor substrate;    a dielectric film of a dual dielectric film structure composed of an Si 3 N 4  chloride-free thin film and a Ta 2 O 5  thin film, which is formed on the lower electrode; and    an upper electrode formed on the dielectric film.    
   
   
       2 . The capacitor in the semiconductor device according to  claim 1 , wherein the lower electrode is made of a polysilicon layer and a hemispherical grain shape polysilicon layer.  
   
   
       3 . The capacitor in the semiconductor device according to  claim 1 , wherein the lower electrode is formed in a stacked structure, a cylindrical structure or a concave structure.  
   
   
       4 . The capacitor in the semiconductor device according to  claim 1 , wherein the upper electrode is made of a structure formed by stacking at least one metallic material selected from the group composed of TiN, TaN, W, WN, Ru, RuO 2 , Ir, IrO 2 , Pt, etc., together with a polysilicon layer.