Interconnection structures in a semiconductor device and methods of manufacturing the same

Abstract

Methods of fabricating interconnection structures of a semiconductor device are provided. The method includes, inter alia: forming a first insulation layer on a semiconductor substrate, forming a mold layer having trenches on the first insulation layer, forming a sidewall protection layer including a first metal silicide layer on sidewalls of the trenches, forming second metal lines that fill the trenches, forming upper protection layers on the second metal lines, removing the mold layer after formation of the upper protection layers to provide gaps between second metal lines, and forming a second insulation layer in the gaps and on the upper protection layers. The second insulation layer is formed to include air gaps between the second metal lines. Related interconnection structures are also provided.