Abstract: The present invention discloses methods for fabricating a semiconductor device. In one embodiment, a conductive interconnection is formed on a semiconductor substrate to overlap with a mask insulating film pattern. An insulating film spacer is formed at side walls of the pattern, a high temperature oxide layer is formed on the resultant structure, and an interlayer insulating film is formed on the HTO film to planarize the surface of the resultant structure. Storage electrode and bit line contact holes are formed to expose the semiconductor substrate, by etching the interlayer insulating film according to a photolithography process using a contact mask. A landing plug poly is formed by depositing a conductive layer for a contact plug to fill up the contact holes.