Abstract: A semiconductor device may include: a first conductive line extending in a first direction; a second conductive line disposed over the first conductive line to be spaced apart from the first conductive line and extending in a second direction different from the first direction; and a selector layer disposed between the first conductive line and the second conductive line and extending in a direction crossing at least one of the first direction or the second direction, wherein the selector layer includes a trench formed on a surface of the selector layer and extending in the direction crossing at least one of the first direction or the second direction.