Semiconductor device and method for manufacturing the smae

A semiconductor device comprising:

• a semiconductor substrate;
• a conductive plug formed on the semiconductor substrate;
• a lower electrode formed in contact with the conductive plug and constituted by a plurality of crystal grains;
• a capacitor insulating film formed on a side of the capacitor lower electrode;
• and
• a upper electrode formed above the lower electrode via the capacitor dielectric film,
• a grain boundary between adjacent two of said plurality of crystal grains constituting the lower electrode being substantially perpendicular to an interface between the lower electrode and the capacitor insulating film.

A semiconductor device comprising:

• a semiconductor substrate;
• a conductive plug formed on the semiconductor substrate;
• a lower electrode formed in contact with the conductive plug;
• a capacitor insulating film formed on a side of the lower electrode;
• and
• a upper electrode formed above the lower electrode via the capacitor insulating film,
• the capacitor insulating film being formed above a top surface of the lower electrode via a second insulating film different from the capacitor insulating film.

A method for manufacturing a semiconductor device comprising the steps of:

• forming on a semiconductor substrate a mask layer having a hole through which a plug electrode is exposed;
• burying a lower electrode in the hole of the mask layer;
• forming a capacitor insulating film covering the lower electrode;
• and
• forming an upper electrode on the capacitor insulating film.