Patent attributes
A vertical-type memory device includes a plurality of gate electrode layers spaced apart from one another and stacked on a substrate, and extending by different lengths in a first direction and forming a staircase structure, a first interlayer insulating layer covering the staircase structure of the plurality of gate electrode layers, and a plurality of gate contact plugs penetrating the interlayer insulating layer and respectively in contact with the gate electrode layers. The plurality of gate electrode layers include lower gate electrode layers disposed adjacently to the substrate, and upper gate electrode layers disposed on the lower gate electrode layers, so that the lower gate electrodes are between the substrate and the upper gate electrode layers. The plurality of gate contact plugs include lower gate contact plugs connected to the lower gate electrode layers, and upper gate contact plugs connected to the upper gate electrode layers. The upper gate contact plugs have top-most portions disposed at a height higher than a height of top surfaces of the lower gate contact plugs.
