There is provided a semiconductor device capable of capable of improving element performance and reliability. A semiconductor device includes a lower conductive pattern disposed on a substrate, an upper conductive pattern disposed on the lower conductive pattern, and a first plug pattern disposed between the lower conductive pattern and the upper conductive pattern and connected to the lower conductive pattern and the upper conductive pattern. The first plug pattern includes a first barrier pattern that defines a first plug recess and a first plug metal pattern that fills the first plug recess, and the first plug metal pattern includes a first molybdenum pattern and a first tungsten pattern disposed on the first molybdenum pattern.

Integrated circuit devices are provided. An integrated circuit device includes an insulating layer and a metal via structure that is in the insulating layer. The metal via structure has a lower portion and an upper portion that is narrower than the lower portion. Moreover, the integrated circuit device includes a metal line that is on and electrically connected to the metal via structure. Related methods of forming integrated circuit devices are also provided.

A semiconductor device structure, along with methods of forming such, are described. The semiconductor device structure includes a device, a first dielectric material disposed over the device, and an opening is formed in the first dielectric material. The semiconductor device structure further includes a conductive structure disposed in the opening, and the conductive structure includes a first sidewall. The semiconductor device structure further includes a surrounding structure disposed in the opening, and the surrounding structure surrounds the first sidewall of the conductive structure. The surrounding structure includes a first spacer layer and a second spacer layer adjacent the first spacer layer. The first spacer layer is separated from the second spacer layer by an air gap.

A semiconductor structure includes a first dielectric layer on a substrate, a conductive structure disposed in the first dielectric layer and including a terminal portion and an extending portion connecting the terminal portion and extending away from the terminal portion, a second dielectric layer disposed on the first dielectric layer, a conductive via through the second dielectric layer and directly contacting the extending portion, and a dummy via through the second dielectric layer and directly contacting the terminal portion. In a cross-sectional view, a width of the dummy via is smaller than 50% of a width of the conductive via.