Semiconductor device comprising a conductive layer having an air gap

Abstract

A semiconductor device includes a substrate, gate electrodes and interlayer insulating layers alternately stacked on the substrate, channel regions penetrating through the gate electrodes and the interlayer insulating layers, a conductive layer penetrating through the gate electrodes and the interlayer insulating layers, an insulating layer covering an upper surface of the conductive layer, a contact plug penetrating through the insulating layer and connected to the conductive layer, and an air gap formed in the conductive layer. The conductive layer is connected to the substrate and extends between two groups of the channel regions. The air gap is defined by the contact plug, insulating layer and an inner sidewall of the conductive layer.