Patent ID: 8749067

Claim:
A semiconductor device, which is formed on a semiconductor substrate and comprises a metal gate, source and drain regions and contact plugs, wherein said source and drain regions are located on both sides of the metal gate and are at least partially embedded into the semiconductor substrate, the contact plugs comprise: first contact plugs comprising a first barrier layer arranged on the source and drain regions, a tungsten layer arranged on the first barrier layer, a second barrier layer arranged on the tungsten layer, and a conductive layer arranged on the second barrier layer; and second contact plugs comprising the second barrier layer arranged on both of the metal gate and the first contact plugs and the conductive layer arranged on the second barrier layer of the second contact plug arranged on the first contact plug, wherein the second barrier layer and the conductive layer are arranged both in the first contact plug on the tungsten layer and in the second contact plug on the metal gate and the first contact plug, and wherein the conductivity of the conductive layer is higher than that of the tungsten layer.