Method of Fabricating semiconductor device
AssigneeNEC Corporation
InventorAkira Kubo
Life of this patent
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Abstract
There is provided a method of fabricating a semiconductor device, including the steps of (a) forming an insulating film on a semiconductor substrate, the insulating film being formed with a contact hole, (b) covering the insulating film with a metal film so that the contact hole is filled with the metal film, and (c) applying polishing such as CMP and wet-etching to the metal film to thereby pattern the metal film into a metal plug or a metal wiring layer. For instance, the insulating film is dipped into etchant or is exposed to vapor of etchant in the wet-etching. Since the insulating film is removed by wet-etching having a smaller removal rate than that of CMP, it is possible to minimize projection of a metal film, ensuring reliability of a semiconductor device.
Claims21
A method of fabricating a semiconductor device, comprising:
- (a) forming an insulating film on a semiconductor substrate, said insulating film being formed with a contact hole;
- (b) covering said insulating film with a metal film so that said contact hole is filled with said metal film;
- (c) polishing said semiconductor device in the area where said metal film is formed until said metal film is substantially removed, thereby exposing said insulating film;
- and subsequently
- (d) wet-etching said insulating film until said metal film in said contact hole extends toward the surface of said semiconductor device at least to the level of said wet-etched insulating film.
A method of planarizing a surface of an insulating film in which a metal plug or a metal wiring layer is buried, comprising:
- (a) polishing a film formed over said insulating film until said film is substantially removed, thereby exposing said insulating film;
- and subsequently
- (b) wet-etching said insulating film until said metal plug or said metal wiring layer extends toward the surface of said insulating film at least to the level of said wet-etched insulating film.
Dependencies are inferred from the claim text.