A semiconductor device includes a cell structure; n first pad structures formed on one side of the cell structure and each configured to have a step form in which 2n layers form one stage; and n second pad structures formed on the other side of the cell structure each configured to have a step form in which 2n layers form one stage, wherein n is a natural number of 1 or higher, and the first pad structures and the second pad structures have asymmetrical step forms having different heights.