Semiconductor devices including contact plugs having silicide layers and methods for fabricating the same

Abstract

A semiconductor device includes an inter-layer dielectric layer over a substrate; a first contact plug structure coupled to a first active region of the substrate by vertically penetrating the inter-layer dielectric layer, and a second contact plug structure coupled to a second active region of the substrate. The first contact plug structure includes a first metal silicide layer; a first contact barrier layer over the first metal silicide layer; and a first contact plug over the first contact barrier layer. The second contact plug structure includes a second metal silicide layer; a second contact barrier layer over the second metal silicide layer; and a second contact plug over the second contact barrier layer. The first and second metal silicide layers include different metal silicides. The first metal silicide layer has a wider horizontal width and a greater vertical height than the second metal silicide layer.