| CPC H10B 43/27 (2023.02) [H01L 23/5226 (2013.01); H10B 41/10 (2023.02); H10B 41/27 (2023.02); H10B 43/10 (2023.02)] | 20 Claims |
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1. A vertical memory device, comprising:
a first gate electrode structure on a first substrate, the first gate electrode structure including first gate electrodes spaced apart from each other in a first direction substantially perpendicular to an upper surface of the first substrate and sequentially stacked in a staircase shape, and each of the first gate electrodes extending in a second direction substantially parallel to the upper surface of the substrate;
a second gate electrode structure on the first gate electrode structure, the second gate electrode structure including second gate electrodes spaced apart from each other in the first direction and sequentially stacked in the staircase shape, and each of the second gate electrodes extending in the second direction;
a channel extending on the first substrate in the first direction through the first and second gate electrode structures; and
first and second contact plugs, each of the first and second contact plugs extending in the first direction through the first and second gate electrode structures,
wherein second steps at respective end portions of the second gate electrodes overlap and are vertically aligned with first steps at respective end portions of the first gate electrodes in the first direction, the first and second steps that are vertically aligned with each other extending to a same length in the second direction,
wherein a first length in the second direction of an uppermost one of the first electrodes is shorter than a second length in the second direction of a lowermost one of the second electrodes, and a third length in the second direction of a lowermost one of the first electrodes equals the second length in the second direction of the lowermost one of the second electrodes,
wherein the first contact plug extends through a corresponding one of the first steps and through a corresponding one of the second steps that is vertically aligned with the corresponding one of the first steps, the first contact plug being electrically connected only to the corresponding one of the first steps among the first steps and the second steps, and
wherein the second contact plug extends through another corresponding one of the first steps and through another corresponding one of the second steps that is vertically aligned with the another corresponding one of the first steps, the second contact plug being electrically connected only to the another corresponding one of the second steps among the first steps and the second steps.
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