Semiconductor devices

Abstract

A semiconductor device includes an active region on a substrate, a plurality of channel layers spaced apart from each other, a gate structure on the substrate, a source/drain region on at least one side of the gate structure, and a contact plug connected to the source/drain region. The contact plug includes a metal-semiconductor compound layer and a barrier layer on the metal-semiconductor compound layer. The contact plug includes a first inclined surface and a second inclined surface positioned where the metal-semiconductor compound layer and the barrier layer directly contact each other. The barrier layer includes first and second ends protruding towards the gate structure. The first and second ends are positioned at a level higher than an upper surface of an uppermost channel layer. An uppermost portion of the metal-semiconductor compound layer is positioned at a level higher than an upper surface of the source/drain region.