Semiconductor device and method for fabricating the same

Abstract

A semiconductor device includes a gate structure on a substrate, a source/drain region adjacent to the gate structure, an interlayer dielectric (ILD) layer around the gate structure, a contact plug in the ILD layer and adjacent to the gate structure, an air gap around the contact plug, a barrier layer on and sealing the air gap, a metal layer on the barrier layer, a stop layer adjacent to the barrier layer and on the ILD layer, and an inter-metal dielectric (IMD) layer on the ILD layer. Preferably, bottom surfaces of the barrier layer and the stop layer are coplanar and top surfaces of the IMD layer and the barrier layer are coplanar.

Dependencies are inferred from the claim text.