Semiconductor device and method for manufacturing the same

Abstract

There is provided a semiconductor device having a ferroelectric capacitor formed on a semiconductor substrate covered with an insulator film, wherein the ferroelectric capacitor comprises: a bottom electrode formed on the insulator film; a ferroelectric film formed on the bottom electrode; and a top electrode formed on the ferroelectric film. The ferroelectric film has a stacked structure of either of two-layer-ferroelectric film or three-layer-ferroelectric film. The upper ferroelectric film is metallized and prevents hydrogen from diffusing in lower ferroelectric layer. Crystal grains of the stacked ferroelectric films are preferably different.

1 . A semiconductor memory device comprising: 
 a semiconductor substrate;    an insulator film formed on said substrate;    a ferroelectric capacitor having a bottom electrode, a ferroelectric film and a top electrode, which are sequentially stacked on said insulator film, said ferroelectric film being patterned on said bottom electrode having a predetermined pattern so as to have an area smaller than an area of said bottom electrode;    an interlayer insulation layer covering the ferroelectric capacitor; and    a hydrogen barrier film deposited on the interlayer insulation layer so that at least a top and side of said ferroelectric capacitor are enveloped via said interlayer insulation layer, wherein an extending portion of said hydrogen barrier film is at a level lower than said insulator film by a predetermined amount.    
   
   
       2 . A semiconductor memory device comprising: 
 a semiconductor substrate;    a first insulator film formed on said substrate;    a ferroelectric capacitor having a bottom electrode, a ferroelectric film and a top electrode, which are sequentially stacked on said first insulator film, said ferroelectric film being patterned on said bottom electrode having a predetermined pattern so as to have an area smaller than an area of said bottom electrode;    a first interlayer insulation layer covering the ferroelectric capacitor;    a first hydrogen barrier film deposited on the first interlayer insulation layer so that at least a top and side of said ferroelectric capacitor are enveloped via said first interlayer insulation layer;    a second interlayer insulation layer covering said first hydrogen barrier film; and    a second hydrogen barrier film deposited on said second interlayer insulation layer, wherein said first and second hydrogen barrier films are disposed in a parallel plane.    
   
   
       3 . A semiconductor memory device comprising: 
 a semiconductor substrate;    an insulator film formed on said substrate;    a ferroelectric capacitor having a bottom electrode, a ferroelectric film and a top electrode, which are sequentially stacked on said insulator film, said ferroelectric film being patterned on said bottom electrode having a predetermined pattern so as to have an area smaller than an area of said bottom electrode;    an interlayer insulation layer covering the ferroelectric capacitor;    a hydrogen barrier film deposited on the interlayer insulation layer so that at least a top and side of said ferroelectric capacitor are enveloped via said interlayer insulation layer; and    a protective film formed on said hydrogen barrier film for protecting against at least one of hydrogen gas and a halogen gas such that a surface of said top electrode and sides of said ferroelectric film and said bottom electrode are covered.    
   
   
       4 . The semiconductor memory device as set forth in  claim 3 , wherein a surface of said top electrode and sides of said ferroelectric film and said bottom electrode are covered with a protective film for protecting against at least one of hydrogen gas and a halogen gas.  
   
   
       5 . A semiconductor device comprising: 
 a semiconductor substrate;    an insulator film formed on said substrate;    a ferroelectric capacitor having a bottom electrode, a ferroelectric film and a top electrode, which are sequentially stacked on said insulator film, said ferroelectric film being patterned on said bottom electrode having a predetermined pattern so as to have an area smaller than an area of said bottom electrode; and    an interlayer insulation layer covering the ferroelectric capacitor, said interlayer insulation layer containing metal oxide material exhibiting hydrogen barrier characteristics.