Semiconductor device and method for manufacturing the same

A method of manufacturing a semiconductor device, which comprises:

• forming a first insulating film having a first hole on a semiconductor substrate;
• forming a first conductive layer filling the first hole to form a flat surface structure;
• forming a second conductive layer on the first insulating film having the first conductive layer, said second conductive layer being in contact with the first insulating film and the first conductive layer;
• forming a dummy film formed of a material selected from the group consisting of a metal, an oxide, and a nitride, on the second conductive layer;
• patterning the dummy film to form a dummy film pattern having a tapered side surface;
• patterning the second conductive layer using the dummy film pattern as a mask to form a lower electrode formed of a part of the second conductive layer;
• forming a second insulating film on an entire surface of a resulted structure;
• removing a surface portion of the second insulating film by means of chemical mechanical polishing to expose the dummy film pattern;
• removing said dummy film pattern to expose said lower electrode, thereby forming a second hole having a tapered sidewall in the second insulating film;
• forming a ferroelectric film on the second insulating film and in the second hole;
• removing a surface region of said ferroelectric film by means of chemical mechanical polishing to expose a surface of said second insulating film, said first hole being filled with the ferroelectric film having a tapered side surface, a surface area of the ferroelectric film being smaller than that of the lower electrode;
• and
• forming an upper electrode on said ferroelectric film thereby forming a capacitor.