Semiconductor device and method of manufacturing the same

1. A semiconductor device manufacturing method, comprising:

forming an underlying insulating film on a semiconductor substrate;

forming a first conductive film, a ferroelectric film, and a second conductive film in sequence on the underlying insulating film;

forming a mask material film on the second conductive film;

forming a resist pattern on the mask material film;

shaping the mask material film into an auxiliary mask, by etching the mask material film while using the resist pattern as a mask;

shaping the second conductive film into an upper electrode, by subjecting the second conductive film to an isotropic etching while using the auxiliary mask and the resist pattern as a mask;

removing the resist pattern;

removing the auxiliary mask;

shaping the ferroelectric film into a capacitor dielectric film by patterning; and

shaping the first conductive film into a lower electrode by patterning the first conductive film, whereby constructing a capacitor from the lower electrode, the capacitor dielectric film, and the upper electrode.

2. A semiconductor device manufacturing method, according to claim 1 , wherein a gas mixture consisting of a halogen gas and an inert gas is used as an etching gas in the etching of the second conductive film.

3. A semiconductor device manufacturing method, according to claim 1 , wherein the etching of the second conductive film is performed by using an ICP (Inductively Coupled Plasma) etching equipment in which a quartz is employed as at least a part of a chamber.

4. A semiconductor device manufacturing method, according to claim 3 , wherein the quartz constitutes a side wall of the chamber.

5. A semiconductor device manufacturing method, according to claim 3 , wherein a gas mixture consisting of a halogen gas and an inert gas is supplied to the chamber as an etching gas, and a volumetric concentration of the inert gas in the etching gas is set to 60% or more in terms of flow rate ratio.

6. A semiconductor device manufacturing method, according to claim 1 , wherein a film whose etching rate is lower than the resist pattern is formed as the mask material film.

7. A semiconductor device manufacturing method, according to claim 1 , wherein the mask material film is formed to have a thickness of 50 nm or less.

8. A semiconductor device manufacturing method, according to claim 1 , wherein a titanium nitride film or a titanium nitride aluminum film is used as the mask material film.

9. A semiconductor device manufacturing method, according to claim 1 , wherein the removing of the auxiliary mask is performed by a wet etching using a mixed solution consisting of hydrogen peroxide and ammonium hydroxide as an etchant.

10. A semiconductor device manufacturing method, according to claim 1 , further comprising:

removing residues on the upper electrode by exposing the upper electrode to an oxygen plasma after the auxiliary mask is removed.

11. A semiconductor device manufacturing method, according to claim 1 , further comprising:

annealing the capacitor dielectric film in an oxygen atmosphere after the capacitor is constructed.

12. A semiconductor device manufacturing method, according to claim 1 , further comprising:

forming an interlayer insulating film to cover the capacitor after the capacitor is constructed.

13. A semiconductor device manufacturing method, according to claim 12 , wherein, when shaping the first conductive film into the lower electrode by the patterning, a contact region of the lower electrode is formed to extend from the capacitor dielectric film, and

further comprising, after forming the interlayer insulating film:

forming a hole in the interlayer insulating film on the contact region of the lower electrode; and

forming a conductive plug, which is connected electrically to the lower electrode, in the hole.

14. A semiconductor device manufacturing method, according to claim 1 , wherein a noble metal film or a noble metal oxide film is formed as the second conductive film.