Patent ID: 8901745

Claim:
A three-dimensional semiconductor device comprising; a substrate including wiring and contact regions; a thin film structure on the wiring and contact regions of the substrate, wherein the thin-film structure includes a plurality of alternating wiring layers and inter-layer insulating layers defining a terraced structure in the contact region so that each of the wiring layers includes a contact surface in the contact region that extends beyond others of the wiring layers more distant from the substrate; and a plurality of contact structures extending in a direction perpendicular to a surface of the substrate wherein each of the contact structures is electrically connected to a contact surface of a respective one of the wiring layers, wherein an interface between one of the contact structures and the respective wiring layer has a total length in a direction parallel to an adjacent edge of the respective wiring layer wherein the total length of the interface is substantially the same as a total length of the adjacent edge of the respective wiring layer.