Patent ID: 6946388

Claim:
A method for fabricating semiconductor devices, comprising the steps of: (a) forming an interlayer insulating film including a landing plug on a semiconductor substrate having a predetermined lower structure; (b) depositing a nitride film on the interlayer insulating film, the nitride film having an etch selectivity different from that of the interlayer insulating film; (c) etching the insulating film via a photolithography process using a contact mask to form a contact hole; (d) sequentially forming a barrier metal layer and a conductive layer for contact plug on the semiconductor substrate; (e) performing a CMP process to etch the conductive layer for contact plug and the barrier metal layer, whereby a contact plug filling the contact hole is formed; (f) depositing a conductive layer for bit line on the surface of the semiconductor substrate; and (g) forming a bit line by etching the conductive layer for bit line.