Semiconductor device with capacitor and method of manufacturing thereof

Abstract

A semiconductor device having a capacitor and a method of manufacturing thereof are provided, securing a certain capacitance while allowing the size to be reduced. The semiconductor device includes a capacitor lower electrode having an upper surface and including a metal film, a dielectric film deposited on the upper surface of the capacitor lower electrode and having its thickness smaller than that of the capacitor lower electrode, and a capacitor upper electrode deposited on the dielectric film, having its width smaller than that of the capacitor lower electrode and including a metal film.

What is claimed is:  
     
         1 . A semiconductor device comprising: 
 a capacitor lower electrode having an upper surface and including a metal film;    a dielectric film deposited on the upper surface of said capacitor lower electrode and having its thickness smaller than that of said capacitor lower electrode; and    a capacitor upper electrode deposited on said dielectric film, having its width smaller than that of said capacitor lower electrode and including a metal film.    
     
     
         2 . The semiconductor device according to  claim 1 , wherein 
 said capacitor upper electrode has a sidewall, and    said semiconductor device includes a sidewall insulating film formed on the upper surface of said capacitor lower electrode and on the sidewall of said capacitor upper electrode.    
     
     
         3 . The semiconductor device according to  claim 2 , wherein 
 said sidewall insulating film includes a silicon oxynitride film.    
     
     
         4 . The semiconductor device according to  claim 1 , wherein 
 said capacitor lower electrode includes aluminum, and    said capacitor upper electrode includes tungsten.    
     
     
         5 . The semiconductor device according to  claim 1 , further comprising: 
 a lower interconnection portion constituted of a layer at the same level as that of said capacitor lower electrode;    another dielectric film deposited on said lower interconnection portion;    an upper interconnection portion deposited on said another dielectric film, having its width smaller than that of said lower interconnection portion, and constituted of a layer at the same level as that of said capacitor upper electrode;    an interlayer insulating film formed on said upper interconnection portion,    a connection hole being formed in said interlayer insulating film to expose a surface of said upper interconnection portion and reach an upper surface of said lower interconnection portion; and    a conductive film provided inside said connection hole to electrically connect said upper interconnection portion and said lower interconnection portion.    
     
     
         6 . A semiconductor device comprising: 
 a capacitor lower electrode having an upper surface and a sidewall surface and including a metal film;    a dielectric film deposited on said capacitor lower electrode to extend from the upper surface to the sidewall surface and having its thickness smaller than that of said capacitor lower electrode; and    a capacitor upper electrode deposited on said dielectric film and including a metal film.    
     
     
         7 . The semiconductor device according to  claim 6 , wherein 
 said capacitor upper electrode has its width smaller than that of said capacitor lower electrode.    
     
     
         8 . The semiconductor device according to  claim 6 , wherein 
 said capacitor upper electrode has its width greater than that of said capacitor lower electrode.    
     
     
         9 . A semiconductor device comprising: 
 an interlayer insulating film having a trench;    a capacitor lower electrode filling inside of said trench and including a metal film;    a dielectric film deposited on said capacitor lower electrode and having its thickness smaller than that of said interlayer insulating film; and    a capacitor upper electrode deposited on said dielectric film and including a metal film.    
     
     
         10 . A semiconductor device comprising: 
 one capacitor electrode including a first extension and a second extension horizontally spaced apart from the first extension; and    the other capacitor electrode including a third extension located between said first extension and said second extension, opposed to said first extension with a dielectric film therebetween and opposed to said second extension with a dielectric film therebetween and including a fourth extension opposed to said second extension with a dielectric film therebetween that is different from the dielectric film between said second and third extensions, said third and fourth extensions located on different sides of said second extension.    
     
     
         11 . A semiconductor device comprising: 
 an interlayer insulating film having a plurality of holes;    a plurality of capacitor lower electrodes respectively provided inside said plurality of holes of said interlayer insulating film and including a metal film;    a dielectric film deposited on said plurality of capacitor lower electrodes; and    a capacitor upper electrode deposited on said dielectric film and including a metal film.    
     
     
         12 . A semiconductor device comprising: 
 a capacitor lower electrode including a metal film;    a dielectric film deposited on said capacitor lower electrode and having its thickness smaller than that of said capacitor lower electrode;    an interlayer insulating film deposited on said dielectric film and having an opening exposing said dielectric film; and    a capacitor upper electrode provided inside said opening and including a metal film.    
     
     
         13 . A method of manufacturing a semiconductor device comprising the steps of: 
 forming a lower metal film constituting a capacitor lower electrode;    forming a dielectric film on said lower metal film;    forming a capacitor upper electrode deposited on said dielectric film and including a metal film; and    forming the capacitor lower electrode by partially removing said lower metal film through etching using said capacitor upper electrode as a mask.    
     
     
         14 . The method of manufacturing a semiconductor device according to  claim 13 , wherein 
 in said step of forming the dielectric film, said dielectric film is formed to extend onto a region where an interconnection is formed by using said lower metal film, and the method further comprises the steps of    forming, prior to said step of forming the capacitor lower electrode, a resist film on said dielectric film in said region where the interconnection is formed by using the lower metal film, and    forming the interconnection by partially removing said lower metal film using said resist film as a mask.    
     
     
         15 . The method of manufacturing a semiconductor device according to  claim 14 , wherein 
 said dielectric film includes a silicon oxynitride film.    
     
     
         16 . The method of manufacturing a semiconductor device according to  claim 13 , further comprising the step of forming, prior to said step of forming the capacitor lower electrode, a sidewall film on a sidewall surface of said capacitor upper electrode, wherein 
 in said step of forming the capacitor lower electrode, said capacitor upper electrode and said sidewall film are used as a mask.    
     
     
         17 . The method of manufacturing a semiconductor device according to  claim 16 , further comprising the steps of: 
 forming, prior to said step of forming the capacitor lower electrode, an upper interconnection portion deposited on said dielectric film, having a sidewall surface, and constituting an interconnection layer;    forming an interconnection sidewall film on the sidewall surface of said upper interconnection portion;    forming a lower interconnection portion by partially removing said lower metal film through etching using said interconnection sidewall film and said upper interconnection portion as a mask;    forming an interlayer insulating film on said upper interconnection portion;    forming a connection hole in said interlayer insulating film, the connection hole exposing a surface of said upper interconnection portion and reaching an upper surface of said lower interconnection portion; and    forming a conductive film inside said connection hole, the conductive film being electrically connected to said upper and lower interconnection portions.