IP Library Granted Patent US 9,865,656
Granted Patent B2
US 9,865,656 · App. 15/271,453 · Granted Jan 9, 2018

Semiconductor memory device

Inventors: Takahisa Kanemura (Yokohama, JP); Takashi Izumida (Yokohama, JP)
Assignee: TOSHIBA MEMORY CORPORATION
H01L27/2481G11C13/004G11C13/0007H01L23/528H01L27/2436H01L45/1233H01L45/146H01L45/1608G11C2013/0045G11C2213/32G11C2213/71G11C2213/75
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Quick Facts
Patent No.
US 9,865,656
App. No.
15/271,453
Granted
Jan 9, 2018
Kind
B2
Abstract

A semiconductor memory device according to an embodiment includes a memory cell array that includes a plurality of memory cells. The memory cell array comprises: a plurality of first conductive layers that are stacked in a first direction above a substrate and extend in a second direction intersecting the first direction; a second conductive layer extending in the first direction; a variable resistance film provided at intersections of the plurality of first conductive layers and the second conductive layer; a first select transistor disposed closer to a side of the substrate than a lowermost layer of the plurality of first conductive layers, the first select transistor including a first select gate line intersecting the second conductive layer; a third conductive layer that extends in a third direction intersecting the second direction and is connected to a lower end of the second conductive layer via the first select transistor; and a second select transistor disposed between at least one pair of the plurality of first conductive layers adjacent in the first direction, the second select transistor including a second select gate line intersecting the second conductive layer.

Claims (29)

1. A semiconductor memory device, including a memory cell array, the memory cell array including a plurality of memory cells, the memory cell array comprising:

a plurality of first conductive layers that are stacked in a first direction above a substrate and extend in a second direction intersecting the first direction;

a plurality of second conductive layers that are stacked in the first direction above the substrate and extend in the second direction, the plurality of second conductive layers being adjacent to the plurality of the first conductive layers in a third direction intersecting the first direction and the second direction;

a third conductive layer extending in the first direction;

a first variable resistance film provided at intersections of the plurality of first conductive layers and the third conductive layer;

a second variable resistance film provided at intersections of the plurality of second conductive layers and the third conductive layer;

a first select transistor disposed closer to the substrate than a lowermost layer of the plurality of first conductive layers, the first select transistor including a first select gate line intersecting the third conductive layer;

a fourth conductive layer that extends in the third direction and is connected to a lower end of the third conductive layer via the first select transistor; and

a second select transistor disposed between at least one pair of the plurality of first conductive layers adjacent in the first direction, the second select transistor including a second select gate line intersecting the third conductive layer.

2. The semiconductor memory device according to claim 1 , wherein two layers of the first select gate lines are provided continuously via an inter-layer insulating film along the first direction.

3. The semiconductor memory device according to claim 1 , wherein the second select gate line has an average width substantially identical to that of the first conductive layer in a direction orthogonal to the first direction and the second direction.

4. The semiconductor memory device according to claim 1 , wherein in the first direction, an average of thickness of the second select gate line is larger than an average of thickness of the first conductive layer.

5. The semiconductor memory device according to claim 1 , further comprising:

a fifth conductive layer extending in the third direction and electrically connected to an upper end of the third conductive layer; and

a third select transistor disposed between the fifth conductive layer and an uppermost layer of the plurality of first conductive layers, the third select transistor including a third select gate line intersecting the third conductive layer.

6. The semiconductor memory device according to claim 1 , wherein one of the first conductive layers is configured from a plurality of regions that are electrically independent.

7. The semiconductor memory device according to claim 1 , wherein the second select gate line disposed between the plurality of first conductive layers adjacent in the first direction has a shape substantially identical to that of one of the first conductive layers when viewed in the first direction.

8. The semiconductor memory device according to claim 1 , wherein the first variable resistance film is divided between intersections of the plurality of first conductive layers and the third conductive layer, and an insulating layer is disposed between the first variable resistance films divided in the first direction.

9. The semiconductor memory device according to claim 1 , wherein the first variable resistance film is disposed between the first select gate line and the third conductive layer.

10. The semiconductor memory device according to claim 1 , wherein an insulating film including silicon is disposed between the first select gate line and the third conductive layer.

11. The semiconductor memory device according to claim 1 , further comprising:

a plurality of sixth conductive layers that are stacked in the first direction above the substrate and extend in the second direction, the plurality of sixth conductive layers being adjacent to the plurality of second conductive layers in the third direction;

a seventh conductive layer that is provided between the plurality of sixth conductive layers and the plurality of second conductive layers and extends in the first direction;

a third variable resistance film provided at intersections of the plurality of second conductive layers and the seventh conductive layer; and

a fourth variable resistance film provided at intersections of the plurality of sixth conductive layers and the seventh conductive layer.

12. The semiconductor memory device according to claim 11 , wherein the plurality of the first conductive layers and the plurality of sixth layers are electrically connected via an electrode member that is made of an identical material to the plurality of first conductive layers and the plurality of sixth layers and is extending in the third direction.

13. The semiconductor memory device according to claim 1 , further comprising:

an eighth conductive layer that is provided adjacent to the third conductive layer in the second direction and between the plurality of first conductive layers and the plurality of second layers, the eighth conductive layer being extending in the first direction; and

an insulating layer provided between the third conductive layer and the eighth conductive layer.

Assignments (5)
MERGER Recorded Jan 22, 2021
From: TOSHIBA MEMORY CORPORATION
To: K.K. PANGEA
Reel/Frame 055659/0471 →
CHANGE OF NAME AND ADDRESS Recorded Jan 22, 2021
From: TOSHIBA MEMORY CORPORATION
To: KIOXIA CORPORATION
Reel/Frame 055669/0001 →
CHANGE OF NAME AND ADDRESS Recorded Jan 22, 2021
From: K.K. PANGEA
To: TOSHIBA MEMORY CORPORATION
Reel/Frame 055669/0401 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Aug 14, 2017
From: KABUSHIKI KAISHA TOSHIBA
To: TOSHIBA MEMORY CORPORATION
Reel/Frame 043541/0381 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Dec 9, 2016
From: KANEMURA, TAKAHISA; IZUMIDA, TAKASHI
To: KABUSHIKI KAISHA TOSHIBA
Reel/Frame 040953/0978 →
Continuity (2)
Provisional Application 62294637 · Feb 12, 2016
Related Publication 20170236872A1 · Aug 17, 2017