Semiconductor memory device

Abstract

Active regions defined by device isolation layer are provided on a substrate. A word line crossing the active regions and a gate dielectric layer between the word line and the active regions are provided. A capping insulating pattern covering an upper surface of the word line and a bit line on the word line are provided. The word line may include a first conductive pattern and a second conductive pattern on the first conductive pattern. The first conductive pattern may include a first metal element. The second conductive pattern may include the first metal element, a work function adjustment element, and a diffusion barrier element. An atomic radius of the diffusion barrier element may be smaller than an atomic radius of the first metal element.