DRAM Capacitor and method of manufacturing the same

摘要

An underlying conductive film (20) made of iridium and having a thickness of about 0.1 µm is formed in a contact hole (19a) formed in an insulating film (19) covering a transistor (17) formed in a substrate (11), except in the top portion of the contact hole. The underlying conductive film covers the sidewall portions of the contact hole and the top surface of the drain region but does not completely fill in the contact hole. A plug (21) made of platinum is filled in the contact hole up to the top portion thereof. Over the contact hole of the insulating film, there is formed a capacitor (28) composed of a lower electrode (25) made of platinum, a capacitor insulating film (26) made of SrBi 2 Ta 2 O 9 , and an upper electrode (27) made of platinum in contact relation with the respective upper ends of the underlying conductive film and the plug.