1.  Field of Invention
Various exemplary embodiments of the present invention relate generally to an electronic device, and more particularly, to a semiconductor device and a method of manufacturing the same. 
2.  Description of Related Art
A non-volatile memory device preserves the stored data even when the power is cut off.  Two-dimensional memory devices in which memory cells are fabricated in a single layer over a silicon substrate have reached physical limits in increasing their degree of integration.  Accordingly, three-dimensional (3D) non-volatile memory devices in which memory cells are stacked in a direction perpendicular to a silicon substrate have been proposed. 
A 3D non-volatile memory device may include interlayer insulating layers and word lines stacked alternately and channel layers passing therethrough, in which memory cells may be stacked along the channel layers.  Additionally, desired memory cells may be selectively driven by coupling contact plugs to the stacked word lines. 
However, since contact plugs need to be formed at various depths to realize the 3D non-volatile memory device configured as described above, manufacturing processes may be difficult to perform.  In addition, a bridge may be formed when the contact plugs pass through the word lines.