Semiconductor device and method for fabricating the same

Abstract

A method for fabricating a semiconductor memory device includes defining an active region having a shape protruding upward by forming a trench in a semiconductor substrate; forming an open region obtained by selectively exposing a lower side portion of the active region while forming a sidewall layer along the shape of the active region; covering the open region with a silicon layer; forming an impurity region in the lower side portion of the active region; forming a barrier metal layer on the silicon layer and the active region; forming a bit line metal layer buried in the entire active region; and forming a buried bit line having the barrier metal layer, the bit line metal layer and a silicide metal layer formed between the silicon layer and the barrier metal layer by etching the bit line metal layer up to a portion at which the impurity region is formed.