CPC H01L 23/5283 (2013.01) [H01L 21/76816 (2013.01); H01L 21/76877 (2013.01); H01L 23/5226 (2013.01); H10B 41/27 (2023.02); H10B 43/27 (2023.02)] | 13 Claims |
1. A three-dimensional memory device, comprising:
first alternating stacks of first insulating layers and first electrically conductive layers located over a substrate, wherein the first alternating stacks laterally extend along a first horizontal direction and are laterally spaced apart along a second horizontal direction that is perpendicular to the first horizontal direction by line trenches, and wherein each of the first alternating stacks comprises a respective first staircase region in which a lateral extent of the first electrically conductive layers along the first horizontal direction decreases with an increasing vertical distance from the substrate;
trench fill structures located between and contacting a respective neighboring pair of the first alternating stacks and filling a respective one of the line trenches;
arrays of memory stack structures vertically extending through a respective one of the first alternating stacks, wherein each of the memory stack structures comprises a respective vertical stack of memory elements located at levels of the first electrically conductive layers;
first retro-stepped dielectric material portions overlying a first staircase region of a respective one of the first alternating stacks, wherein one of the first retro-stepped dielectric material portions has a vertical cross-sectional profile within a vertical plane that is perpendicular to the first horizontal direction in which:
a first boundary of the one of the first retro-stepped dielectric material portions continuously extends from a first horizontal plane including a bottommost surface of the one of first retro-stepped dielectric material portions to a second horizontal plane including topmost surfaces of the first alternating stacks; and
a second boundary of the one of the first retro-stepped dielectric material portions continuously extends from the first horizontal plane to a first point on a sidewall of a respective one of the trench fill structures, the first point being located at a height located between the first horizontal plane and the second horizontal plane.
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