Semiconductor device, RF-IC and manufacturing method of the same

Abstract

Provided is a technology capable of reducing parasitic capacitance of a capacitor while reducing the space occupied by the capacitor. A stacked structure is obtained by forming, over a capacitor composed of a lower electrode, a capacitor insulating film and an intermediate electrode, another capacitor composed of the intermediate electrode, another capacitor insulating film and an upper electrode. Since the intermediate electrode has a step difference, each of the distance between the intermediate electrode and lower electrode and the distance between the intermediate electrode and upper electrode in a region other than the capacitor formation region becomes greater than that in the capacitor formation region. For example, the lower electrode is brought into direct contact with the capacitor insulating film in the capacitor formation region, while the lower electrode is not brought into direct contact with the capacitor insulating film in the region other than the capacitor formation region.

1 . A semiconductor device comprising: 
 a first electrode made of a metal film;    a first capacitor insulating film formed over the first electrode;    a second electrode made of a metal film and formed over the first capacitor insulating film;    a second capacitor insulating film formed over the second electrode; and    a third electrode made of a metal film and formed over the second capacitor insulating film,    wherein the first electrode includes a capacitor having a portion not in direct contact with the first capacitor insulating film.    
   
   
       2 . A semiconductor device according to  claim 1 , 
 wherein a first insulating film is formed between the portion of the first electrode not in direct contact with the first capacitor insulating film and the first capacitor insulating film.    
   
   
       3 . A semiconductor device according to  claim 1 , 
 wherein the second electrode has a portion not in direct contact with the second capacitor insulating film.    
   
   
       4 . A semiconductor device according to  claim 3 , 
 wherein a second insulating film is formed between the portion of the second electrode not in direct contact with the second capacitor insulating film and the second capacitor insulating film.    
   
   
       5 . A semiconductor device according to  claim 1 , 
 wherein the contact area of the first capacitor insulating film with the first electrode is greater than the contact area of the second capacitor insulating film with the second electrode.    
   
   
       6 . A semiconductor device according to  claim 1 , 
 wherein the second electrode is used as a signal interconnect or power supply interconnect.    
   
   
       7 . A semiconductor device according to  claim 1 , 
 wherein the first electrode is in direct contact with the first capacitor insulating film in a capacitance formation region.    
   
   
       8 . A semiconductor device according to  claim 1 , 
 wherein the first electrode is electrically connected to the third electrode.    
   
   
       9 . A semiconductor device according to  claim 8 , 
 wherein a first capacitor having the first electrode, the first capacitor insulating film and the second electrode is connected in parallel to a second capacitor having the second electrode, the second capacitor insulating film and the third electrode.    
   
   
       10 . A semiconductor device according to  claim 9 , 
 wherein a third capacitor is formed over the second capacitor and the third capacitor is connected in parallel to the first capacitor and the second capacitor.    
   
   
       11 . A semiconductor device according to  claim 9 , 
 wherein a fourth capacitor is formed in a region other than the formation regions of the first capacitor and the second capacitor, and the fourth capacitor is connected in parallel to the first capacitor and the second capacitor.    
   
   
       12 . A semiconductor device according to  claim 1 , 
 wherein the second electrode has a step difference disposed therein.    
   
   
       13 . A semiconductor device according to  claim 12 , 
 wherein the step difference has, over the side surfaces thereof, sidewalls made of an insulating film.    
   
   
       14 . A semiconductor device according to  claim 1 , 
 wherein the first electrode, the second electrode and the third electrode are each made of an aluminum film or tungsten film.    
   
   
       15 . A semiconductor device according to  claim 1 , 
 wherein the first capacitor insulating film and the second capacitor insulating film are each made of any one of a silicon oxide film, a silicon nitride film, an alumina film, or a film containing an oxide of tantalum or hafnium.    
   
   
       16 .- 20 . (canceled)