Semiconductor device and method for fabricating the same
The semiconductor device of the invention includes a capacitor device, which is formed on a substrate and which includes a capacitive lower electrode, a capacitive insulating film made of an insulating metal oxide film and a capacitive upper electrode. An interlevel insulating film having an opening reaching the capacitive upper electrode is formed over the capacitor device. A metal interconnection including a titanium film is formed over the interlevel insulating film so as to be electrically connected to the capacitive upper electrode through the opening. An anti-diffusion film having conductivity is formed between the capacitive upper electrode and the metal interconnection for preventing titanium atoms composing the titanium film of the metal interconnection from passing through the capacitive upper electrode and diffusing into the capacitive insulating film.
1 - 15 . (Cancelled)
16 . A method for fabricating a semiconductor device, comprising the steps of:
sequentially stacking a first metal film, an insulating metal oxide film, a second metal film and a conductive film, which prevents the passage of titanium atoms therethrough, on a substrate;
patterning the second metal film and the conductive film by using the same etching mask, thereby forming a capacitive upper electrode out of the second metal film and an anti-diffusion film out of the conductive film;
patterning the insulating metal oxide film to form a capacitive insulating film and patterning the first metal film to form a capacitive lower electrode;
forming an interlevel insulating film, having a contact hole reaching the capacitive upper electrode, over a capacitor device constituted by the capacitive lower electrode, the capacitive insulating film and the capacitive upper electrode; and
forming, on the interlevel insulating film, a metal interconnection including a titanium film such that the metal interconnection is electrically connected to the capacitive upper electrode via the anti-diffusion film.
17 . The method for fabricating a semiconductor device of claim 16 , wherein the conductive film is a metal nitride film or metal oxide film having conductivity.
18 . The method for fabricating a semiconductor device of claim 16 , wherein the capacitive insulating film is a ferroelectric film or a high dielectric film.
19 . The method for fabricating a semiconductor device of claim 16 , wherein the titanium film is an adhesive layer, formed as a lowermost layer of the metal interconnection, for improving adhesion between the metal interconnection and the capacitive upper electrode, and wherein the anti-diffusion film is a titanium nitride film.
20 . The method for fabricating a semiconductor device of claim 16 , wherein the capacitive upper electrode has a crystal structure including a grain boundary.
21 - 25 . (Cancelled)