Memories with cylindrical read/write stacks
AssigneeSanDisk 3D LLC
InventorsHenry Chien, Yao-Sheng Lee, George Samachisa, Johann Alsmeier
Life of this patent
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Abstract
A three-dimensional memory is formed as an array of memory elements across multiple layers positioned at different distances above a semiconductor substrate. Cylindrical stacks of memory elements are formed where a cylindrical opening has read/write material deposited along its wall, and a cylindrical vertical bit line formed along its central axis. Memory elements formed on either side of such a cylinder may include sheet electrodes that extend into the read/write material.
Claims14
A three-dimensional array of read/write elements comprising:
- a plurality of horizontal line stacks, each horizontal line stack comprising a plurality of electrically-conductive horizontal lines that extend in a first direction and are vertically separated from each other by insulating material, individual stacks separated from adjacent stacks in a second direction that is perpendicular to the first direction;
- a plurality of cylinders of read/write material located between a first horizontal line stack and a second horizontal line stack so that each cylinder of the plurality of cylinders is in electrical contact with horizontal lines of the first and second horizontal line stacks;
- a plurality of vertical lines, each vertical line extending through a corresponding cylinder of read/write material to form read/write elements between the vertical line and horizontal lines of the first and second horizontal line stacks;
- wherein the electrically-conductive horizontal lines of the first and second horizontal line stacks include sheet electrodes that extend towards the vertical lines, a sheet electrode having a vertical thickness that is less than the total vertical thickness of a horizontal line;
- and
- wherein the sheet electrode extends horizontally into a cylinder of read/write material.
A three-dimensional nonvolatile memory cell comprising:
- a first electrode that is formed by a cylinder of a first electrically-conductive material, the cylinder having an axis that extends in a first direction;
- a second electrode that is formed from a sheet of a second electrically-conductive material that extends along a plane that is perpendicular to the first direction;
- a read/write material between the first electrode and the second electrode the read/write material formed with a cylindrical outer surface;
- and
- the second electrode extending through the cylindrical outer surface.
Dependencies are inferred from the claim text.