Semiconductor device and method of fabricating the same

Abstract

A semiconductor device includes a substrate having a substrate groove extending in a first direction, a gate insulating layer conformally covering an inner wall of the substrate groove, a metal-containing pattern on the gate insulating layer and filling a lower portion of the substrate groove, a silicon pattern on the metal-containing pattern in the substrate groove, and a word line capping pattern on the silicon pattern in the substrate groove, wherein the silicon pattern includes a first silicon pattern covering an upper surface of the metal-containing pattern and a sidewall of the gate insulating layer and having a pattern groove formed thereon and a second silicon pattern filling the pattern groove, the first silicon pattern having a first impurity concentration, and the second silicon pattern having a second impurity concentration less than the first impurity concentration.