Semiconductor device and manufacturing method for same

Abstract

A semiconductor device and a manufacturing method for the same are provided in such a manner that the oxygen barrier film and the conductive plug in the base of a capacitor are prevented from being abnormally oxidized. A capacitor is formed by layering a lower electrode, a dielectric film including a ferroelectric substance or a high dielectric substance, and an upper electrode in this order on top of an interlayer insulation film with at least a conductive oxygen barrier film in between, and at least a portion of a side of the conductive oxygen barrier film is covered with an oxygen entering portion or an insulating oxygen barrier film.

What is claimed is: 
     
         1 . A semiconductor device, comprising: a semiconductor substrate; an impurity region formed in the semiconductor substrate; an interlayer insulation film formed on top of the semiconductor substrate; a conductive plug formed through the interlayer insulation film and electrically connected to the impurity region; and a capacitor formed of a lower electrode provided on the interlayer insulation film with at least a conductive oxygen barrier film in between, a dielectric film including a ferroelectric substance or a high dielectric substance, and an upper electrode layered on top of each other in this order, characterized in that at least a portion of a side of the conductive oxygen barrier film is covered with an oxide film. 
     
     
         2 . The semiconductor device according to  claim 1 , characterized in that the oxide film is an oxygen entering portion of a side of the conductive oxygen barrier film. 
     
     
         3 . The semiconductor device according to  claim 1 , characterized in that the oxide film is an insulating oxide barrier film. 
     
     
         4 . The semiconductor device according to  claim 1 , characterized in that the conductive oxygen barrier film is provided above the conductive plug in such a position as to overlap the conductive plug as viewed in the direction in which the conductive oxygen barrier film is layered, and the conductive film and the conductive oxygen barrier film are electrically connected to each other. 
     
     
         5 . The semiconductor device according to  claim 4 , further comprising a conductive adhesive film between the conductive oxygen barrier film and the conductive plug. 
     
     
         6 . The semiconductor device according to  claim 5 , characterized in that the thickness of the conductive adhesive film is 1 nm to 20 nm. 
     
     
         7 . The semiconductor device according to  claim 5 , characterized in that the conductive adhesive film includes a conductor selected from among the group consisting of Ti, TiN, Ta, TaN, Pt, Ir, Re, Ru, Pd, Os, Al, and alloys that include any of these metals. 
     
     
         8 . The semiconductor device according to  claim 1 , characterized in that the conductive oxygen barrier film is a single layer film including any of a substance selected from the group consisting of TiAlN, TiAlON, TaAlN, TaAlON, HfAlN, HfAlON, IrSiN, IrSiON, IrAlN, IrAlON, RuSiN, RuSiON, Ir, Ru, TiN, TaN, and HfN, or a multilayer film of any of these. 
     
     
         9 . The semiconductor device according to  claim 2 , characterized in that the area of the surface of the conductive oxygen barrier film that faces the lower electrode and includes the oxygen entering portion and the area of the surface of the lower electrode that faces the conductive oxygen barrier film are substantially equal. 
     
     
         10 . The semiconductor device according to  claim 3 , characterized in that the area of the surface of the conductive oxygen barrier film that faces the lower electrode is smaller than the area of the surface of the lower electrode that faces the conductive oxygen barrier film, and a side of the conductive oxygen barrier film is covered with the insulating oxygen barrier film. 
     
     
         11 . The semiconductor device according to  claim 1 , characterized in that a hydrogen permeation preventing film is inserted into an interlayer insulation film that covers the capacitor. 
     
     
         12 . A manufacturing method for a semiconductor device, characterized by comprising: embedding a conductive plug electrically connected to an impurity region in an interlayer insulation film provided on a semiconductor substrate in which the impurity region is formed; forming at least a conductive oxygen barrier film, a lower electrode, a dielectric film including a ferroelectric substance or a high dielectric substance, and an upper electrode on top of the interlayer insulation film in which the conductive plug is embedded; forming a capacitor with the conductive oxygen barrier film by etching the conductive oxygen barrier film, the lower electrode, the dielectric film including a ferroelectric substance or a high dielectric substance, and the upper electrode; and forming an oxide film in at least a portion of a side of the conductive oxygen barrier film. 
     
     
         13 . The manufacturing method for a semiconductor device according to  claim 12 , characterized in that the process of forming an oxide film includes the formation of an oxygen entering portion of a side of the conductive oxygen barrier film. 
     
     
         14 . The manufacturing method for a semiconductor device according to  claim 12 , characterized in that the process of forming an oxide film includes the formation of an insulating oxygen barrier film. 
     
     
         15 . The manufacturing method for a semiconductor device according to  claim 12 , the process of forming at least a conductive oxygen barrier film, a lower electrode, a dielectric film including a ferroelectric substance or a high dielectric substance, and an upper electrode on top of the interlayer insulation film in which the conductive plug is embedded includes the formation of a conductive adhesive film between the conductive plug and the conductive oxygen barrier film. 
     
     
         16 . The manufacturing method for a semiconductor device according to  claim 13 , characterized in that the process of forming an oxygen entering portion in at least a portion of a side of the conductive oxygen barrier film includes the etching of the lower electrode, the dielectric film including a ferroelectric substance or a high dielectric substance, and the upper electrode up to the point when the conductive oxygen barrier film is exposed, which is then followed by heat treatment in an oxygen atmosphere. 
     
     
         17 . The manufacturing method for a semiconductor device according to  claim 13 , characterized in that the process of forming an oxygen entering portion in at least a portion of a side of the conductive oxygen barrier film includes the formation of an oxygen entering portion on the entire surface of a side of the conductive oxygen barrier film by means of the collective etching of the conductive oxygen barrier film, the lower electrode, the dielectric film including a ferroelectric substance or a high dielectric substance, and the upper electrode, which is then followed by heat treatment in an oxygen atmosphere. 
     
     
         18 . The manufacturing method for a semiconductor device according to  claim 17 , characterized in that the temperature of the heat treatment in an oxygen atmosphere is 400° C. to 500° C. 
     
     
         19 . The manufacturing method for a semiconductor device according to  claim 14 , characterized in that the process of forming at least a conductive oxygen barrier film, a lower electrode, a dielectric film including a ferroelectric substance or a high dielectric substance, and an upper electrode on top of the interlayer insulation film in which the conductive plug is embedded includes: forming a conductive oxygen barrier film, which is then processed into a first form; and forming a lower electrode, a dielectric film including a ferroelectric substance or a high dielectric substance, and an upper electrode on the entire surface that includes the processed conductive oxygen barrier film, and the process of forming an insulating oxygen barrier film includes the formation of an insulating oxygen barrier film on a surface exposed from the conductive oxygen barrier film that has been processed in the first form.