SEMICONDUCTOR STORAGE DEVICE AND ITS MANUFACTURING METHOD

摘要

PROBLEM TO BE SOLVED: To surely improve the barrier property of an iridium oxide film contained in the lower electrode of a capacitance element as an oxygen barrier film. SOLUTION: An interlayer insulating film 14 is formed on a semiconductor substrate 10 to cover a field-effect transistor, and a contact plug 15 is formed in the insulating film 14 so that the plug 15 may be connected to the drain region 12. The lower electrode 16 of the capacitance element is formed on the insulating film 14 so that the electrode 16 may be connected to the plug 15 and the electrode 16 is constituted of a first-conductivity barrier film 16a, a second-conductivity iridium oxide barrier film (oxygen barrier film) 16b, and a metallic film 16c. The mean crystal grain diameter of the granular crystals constituting the barrier film 16b is adjusted to <=1/2 of the thickness of the film 16.