Dielectric memory device and method for fabricating the same

A method for fabricating a dielectric memory device, comprising the steps of:

• forming a first lower electrode above a substrate;
• forming a first insulating film on the first lower electrode;
• forming a hole through the first insulating film down to an upper surface of the first lower electrode;
• performing etching to remove a portion of the first lower electrode exposed at the bottom of the hole, thereby forming a recess in the first lower electrode and a second lower electrode on the sides of the hole, the second lower electrode being made of a material having formed the portion of the first lower electrode removed during formation of the recess;
• forming a capacitor insulating film on the sides and bottom of the recess and on the second lower electrode so that the hole is not fully filled with the film;
• and
• forming an upper electrode on the capacitor insulating film.

A dielectric memory device comprising:

• a first lower electrode formed above a substrate;
• a first insulating film formed on the first lower electrode and having a hole reaching an upper surface of the first lower electrode;
• a second lower electrode formed on the sides of the hole;
• a capacitor insulating film formed on the first and second lower electrodes so that the hole is not fully filled with the film;
• and
• an upper electrode formed on the capacitor insulating film,
• wherein in the second lower electrode on the sides of the hole, a lower portion thereof on the lower part of the hole sides has a greater thickness than an upper portion thereof on the upper part of the hole sides.

A dielectric memory device comprising:

• a first lower electrode formed above a substrate and having a recess in an upper portion thereof;
• a first insulating film formed on the first lower electrode and having a hole reaching the recess;
• a second lower electrode formed on the sides of the hole and having sidewalls continuous with the sides of the recess;
• a capacitor insulating film formed on the sides and bottom of the recess and on the second lower electrode so that the hole is not fully filled with the film;
• and
• an upper electrode formed on the capacitor insulating film,
• wherein in the second lower electrode on the sides of the hole, a lower portion thereof on the lower part of the hole sides has a greater thickness than an upper portion thereof on the upper part of the hole sides.