A semiconductor device includes a first connection pattern; a bit line disposed over the first connection pattern in a vertical direction; and a bit-line contact pad, disposed in a first layer between the bit line and the first connection pattern to electrically couple the bit line to the first connection pattern, and formed as an island when viewed along the vertical direction. A predetermined number of the bit-line contact pads are spaced apart from each other by a predetermined distance in a first direction, when viewed along the vertical direction.