CPC H01L 23/5283 (2013.01) [H01L 21/76816 (2013.01); H01L 21/76877 (2013.01); H01L 23/5226 (2013.01)] | 14 Claims |
1. A microelectronic device, comprising:
a stack structure comprising a vertically alternating sequence of conductive structures and insulating structures arranged in tiers, a dielectric-filled opening vertically extending into the stack structure and defined between two substantially vertical internal sidewalls of the stack structure defined by horizontal ends of an uppermost group of the tiers;
stadium structures within the stack structure, each of the stadium structures comprising a first staircase structure and a second staircase structure symmetrical with and opposing the first staircase structure, the first staircase structure and the second staircase structure respectively having steps defined by horizontal ends of an additional group of the tiers vertically below the uppermost group of the tiers;
two opposing ledges defined by horizontal ends of a further group of the tiers vertically extending from and between the uppermost group of the tiers and the additional group of the tiers, the two opposing ledges comprising:
a first ledge extending from an uppermost one of the steps of the first staircase structures of the respective stadium structure to a first of the two substantially vertical internal sidewalls of the stack structure; and
a second ledge extending from an uppermost one of the steps of the second staircase structures of the respective stadium structure to a second of the two substantially vertical internal sidewalls of the stack structure.
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