A semiconductor device is provided. The semiconductor device includes a substrate containing deuterium at a first concentration, an active pattern disposed on the substrate and extending in a first horizontal direction, a gate electrode disposed on the active pattern and extending in a second horizontal direction different from the first horizontal direction, a gate insulating layer disposed between the active pattern and the gate electrode, the gate insulating layer containing deuterium at a second concentration, a first interlayer insulating layer disposed on the gate electrode, a second interlayer insulating layer disposed on the first interlayer insulating layer, and a wiring pattern disposed inside the second interlayer insulating layer, the wiring pattern containing deuterium at a third concentration lower than the first concentration, wherein each of the first to third concentrations is a concentration of deuterium atoms contained in the same unit volume.