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US 10,381,366 B1Granted
Air gap three-dimensional cross rail memory device and method of making thereof
AssigneeSanDisk Technologies LLC
InventorsYuji Takahashi, Satoru Mayuzumi, Vincent Shih
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Abstract
A memory device includes first conductive rails laterally extending along a first horizontal direction over a substrate, a rectangular array of first memory pillar structures, each containing a memory element, overlying top surfaces of the first conductive rails, second conductive rails laterally extending along a second horizontal direction and overlying top surfaces of the rectangular array of first memory pillar structures, and a one-dimensional array of first cavities free of solid material portions therein, laterally extending along the second horizontal direction and located between neighboring pairs of the second conductive rails.
Claims14
A memory device, comprising:
- first conductive rails laterally extending along a first horizontal direction over a substrate;
- a rectangular array of first memory pillar structures overlying top surfaces of the first conductive rails, wherein each first memory pillar structure comprises a respective memory element;
- second conductive rails laterally extending along a second horizontal direction and overlying top surfaces of the rectangular array of first memory pillar structures;
- and
- a one-dimensional array of first cavities free of solid material portions therein laterally extending along the second horizontal direction and located between neighboring pairs of the second conductive rails;
- wherein each first memory pillar structure comprises a series connection of a respective first selector element and a respective first memory element;
- and
- wherein each first selector element comprises:
- an ovonic threshold switch material portion;
- an upper amorphous carbon portion that contacts a top surface of the ovonic threshold switch material portion;
- and
- a lower amorphous carbon portion that contacts a bottom surface of the ovonic threshold switch material portion.
9 more elements
A memory device, comprising:
- first conductive rails laterally extending along a first horizontal direction over a substrate;
- a rectangular array of first memory pillar structures overlying top surfaces of the first conductive rails, wherein each first memory pillar structure comprises a respective memory element;
- second conductive rails laterally extending along a second horizontal direction and overlying top surfaces of the rectangular array of first memory pillar structures;
- a one-dimensional array of first cavities free of solid material portions therein laterally extending along the second horizontal direction and located between neighboring pairs of the second conductive rails;
- a rectangular array of second memory pillar structures overlying top surfaces of the second conductive rails, wherein each second memory pillar structure comprises a series connection of a respective second selector element and a respective second memory element;
- and
- a rectangular array of dielectric isolation pillars located between each neighboring pair of second memory pillar structures spaced along the first horizontal direction,
- wherein:
- each first memory pillar structure comprises a series connection of a respective first selector element and a respective first memory element;
- each of the first cavities has a vertical cross-sectional shape within a vertical plane that is perpendicular to the first horizontal direction;
- a top portion of the vertical cross-sectional shape includes two vertically protruding regions laterally spaced by a vertically recessed region;
- the vertical cross-sectional shape is entirely enclosed by an inner surface of at least one dielectric liner located between a respective neighboring pair of second conductive rails and between a respective pair of neighboring rows of the first memory pillar structures that are spaced apart along the first horizontal direction;
- each first cavity underlies a respective one of the dielectric isolation pillars;
- each of the dielectric isolation pillars includes a pair of concave bottom surfaces that laterally extend along the second horizontal direction and a downward-protruding portion located between the pair of concave bottom surfaces;
- and
- each pair of concave bottom surfaces of the dielectric isolation pillars contacts a respective one of the at least one dielectric liners.
13 more elements
Dependencies are inferred from the claim text.