Semiconductor device having a stacked capacitor

Abstract

A stacked capacitor in a memory cell has a bottom electrode made of a metal or metal compound, a capacitor insulation film and a top electrode made of a metal or a metal compound. The capacitor insulation film includes an aluminum oxide film having a thickness of 2 to 4 nm and in contact with the bottom electrode, and an overlying hafnium oxide film having a thickness of 3 to 6 nm. The stacked capacitor has a higher resistance against a biased temperature test.

1 . A semiconductor device comprising a stacked capacitor including a bottom electrode, a capacitor insulation film and a top electrode consecutively deposited, wherein: 
 each of said bottom and top electrodes includes a metal or a metal compound; and    said capacitor insulation film includes an aluminum oxide film having a thickness of 2 to 5 nm and disposed in contact with said bottom electrode.    
   
   
       2 . The semiconductor device according to  claim 1 , wherein said capacitor insulation film further includes a hafnium oxide film having a thickness of 3 to 6 nm and disposed in contact with said aluminum oxide film.  
   
   
       3 . The semiconductor device according to  claim 2 , wherein said capacitor insulation film further includes another aluminum oxide film, said hafnium oxide is sandwiched between said aluminum oxide film and said another aluminum oxide film, and sum of thicknesses of said aluminum oxide film and said another aluminum oxide film is 2 to 5 nm.  
   
   
       4 . The semiconductor device according to  claim 2 , wherein said hafnium oxide is amorphous.  
   
   
       5 . The semiconductor device according to  claim 1 , wherein each of said bottom and top electrodes includes a material selected from the group consisting of titanium, tungsten, ruthenium, titanium nitride, and tungsten nitride.  
   
   
       6 . A semiconductor device comprising a stacked capacitor including a bottom electrode, a capacitor insulation film and a top electrode consecutively deposited, wherein: 
 each of said bottom and top electrodes includes a metal  5  or a metal compound; and    said capacitor insulation film has a three-layer structure including a first aluminum oxide film, a hafnium oxide film and a second aluminum oxide film consecutively deposited.    
   
   
       7 . The semiconductor device according to  claim 6 , wherein a sum of thicknesses of said first and second aluminum oxide films is 2 to 5 nm.  
   
   
       8 . The semiconductor device according to  claim 6 , wherein said hafnium oxide film has a thickness of 3 to 6 nm.  
   
   
       9 . The semiconductor device according to  claim 6 , wherein said hafnium oxide is polycrystalline.  
   
   
       10 . The semiconductor device according to  claim 6 , wherein each of said bottom and top electrodes includes a material selected from the group consisting of titanium, tungsten, ruthenium, titanium nitride, and tungsten nitride.  
   
   
       11 . A method for manufacturing a stacked capacitor in a semiconductor device, said method consecutively comprising: 
 forming a bottom electrode including a metal or a metal compound overlying a substrate;    forming a capacitor insulation film including an aluminum oxide film on said bottom electrode, said aluminum oxide film having a thickness of 2 to 5 nm; and    forming a top electrode including a metal or a metal compound on said capacitor insulation film.    
   
   
       12 . The method according to  claim 11 , wherein said capacitor insulation film further a hafnium oxide film in contact with said aluminum oxide film and having a thickness of 3 to 6 nm  
   
   
       13 . A method for manufacturing a stacked capacitor in a semiconductor device, consecutively comprising: 
 forming a bottom electrode including a metal or a metal compound overlying a substrate;    forming a capacitor insulation film on said bottom electrode, said capacitor insulation film including a first aluminum oxide film, a hafnium oxide film and a second aluminum oxide film in this order as viewed from said bottom electrode; and    forming a top electrode including a metal or a metal compound on said capacitor insulation film.    
   
   
       14 . The method according to  claim 13 , wherein said capacitor insulation film forming step consecutively includes depositing said first aluminum oxide film, depositing said hafnium oxide film in an amorphous state, depositing said second aluminum oxide film, and polycrystallizing said deposited hafnium oxide film.  
   
   
       15 . The method according to  claim 13 , wherein said capacitor insulation film forming step consecutively includes depositing said first aluminum oxide film, depositing said hafnium oxide film in an amorphous state, polycrystallizing said deposited hafnium oxide film, and depositing said second aluminum oxide film.  
   
   
       16 . The method according to  claim 13 , wherein said capacitor insulation film forming step includes depositing said hafnium oxide film in an amorphous state, and said top electrode forming step includes polycrystallizing said deposited hafnium oxide film.  
   
   
       17 . The method according to  claim 13 , wherein a sum of thicknesses of said first and second aluminum oxide films is 2 to 5 nm.  
   
   
       18 . The method according to  claim 13 , wherein said hafnium oxide film has a thickness of 3 to 6 nm.