IP Library Granted Patent US 9,236,122
Granted Patent B2
US 9,236,122 · App. 14/340,454 · Granted Jan 12, 2016

Shared-gate vertical-TFT for vertical bit line array

Inventors: Tianhong Yan (Saratoga, CA); George Samachisa (San Jose, CA); Tz-yi Liu (Palo Alto, CA); Tim Chen (Milpitas, CA); Perumal Ratnam (Fremont, CA)
Assignee: SANDISK 3D LLC
G11C13/0069G11C13/0002G11C13/003G11C13/0023H01L27/0688H01L27/249H01L27/2454H01L27/2481H01L45/06H01L45/08H01L45/085H01L45/1233H01L45/1266H01L45/142H01L45/143H01L45/144H01L45/146H01L45/16H01L45/1608G11C7/18G11C2013/0073G11C2013/0083G11C2207/005G11C2213/15G11C2213/71G11C2213/77G11C2213/79H01L27/101
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Quick Facts
Patent No.
US 9,236,122
App. No.
14/340,454
Granted
Jan 12, 2016
Kind
B2
Abstract

A non-volatile storage device comprises: a substrate; a monolithic three dimensional array of memory cells; word lines connected to the memory cells; global bit lines; vertical bit lines connected to the memory cells; and a plurality of double gated vertically oriented select devices. The double gated vertically oriented select devices are connected to the vertical bit lines and the global bit lines so that when the double gated vertically oriented select devices are activated the vertical bit lines are in communication with the global bit lines. Each double gated vertically oriented select device has two gates that are offset from each other with respect to distance to the substrate. Both gates for the double gated vertically oriented select device need be in an “on” condition for the double gated vertically oriented select devices to be activated.

Claims (100)

1. A non-volatile storage system, comprising:

a substrate;

a monolithic three dimensional arrangement of memory cells positioned above and not in the substrate;

a plurality of word lines connected to the memory cells;

a plurality of global bit lines;

a plurality of vertically oriented bit lines connected to the memory cells; and

a plurality of double gated vertically oriented select devices that are above and not in the substrate, the double gated vertically oriented select devices are connected to the vertically oriented bit lines and the global bit lines so that when the double gated vertically oriented select devices are activated the vertically oriented bit lines are in communication with the global bit lines, each double gated vertically oriented select device has two gates that are offset from each other with respect to distance to the substrate with only one gate on each of two sides of the double gated vertically oriented select device so that both gates for the double gated vertically oriented select device need be in an “on” condition for the double gated vertically oriented select devices to be activated.

2. The non-volatile storage system of claim 1 , wherein:

the first of the two gates is adjacent to a drain of the double gated vertically oriented select device but not adjacent to a source of the double gated vertically oriented select device and a second of the two gates is adjacent to the source of the double gated vertically oriented select device but not adjacent to the drain of the double gated vertically oriented select device.

3. The non-volatile storage system of claim 2 , wherein:

the double gated vertically oriented select devices each comprise only one transistor.

4. The non-volatile storage system of claim 3 , wherein:

the one transistor includes two source/drain regions;

during a programming operation, the two gates create two channels, one channel for each gate; and

during the programming operation, the two source/drain regions are depleted and short the two channels.

5. The non-volatile storage system of claim 1 , wherein:

each double gated vertically oriented select device includes two middle conductivity regions each between source/drain regions; and

a first of the two gates adjacent to a first conductivity region of the two middle conductivity regions but not adjacent to a second conductivity region of the middle conductivity regions and a second of the two gates adjacent to the second conductivity region of the middle conductivity regions but not adjacent to the first conductivity region of the conductivity regions.

6. The non-volatile storage system of claim 5 , wherein:

the double gated vertically oriented select devices each comprise two transistors in series;

the first of the two gates is part of one of the two transistors;

the second of the two gates is part of a second of the two transistors so that current from a selected global bit lines passes through both of the two transistors when the double gated vertically oriented select device is in the “on” condition.

7. The non-volatile storage system of claim 5 , wherein:

the first of the two gates creates a first channel in the first conductivity region of the two middle conductivity regions; and

the second of the two gates creates a second channel in the second conductivity region of the two middle conductivity regions.

8. The non-volatile storage system of claim 1 , wherein:

each double gated vertically oriented select device includes two middle conductivity regions each between source/drain regions; and

both of the two gates are adjacent both of the two middle conductivity regions.

9. The non-volatile storage system of claim 8 , wherein:

the double gated vertically oriented select devices each comprise two transistors in series;

the first of the two gates is part of one of the two transistors;

the second of the two gates part of a second of the two transistors so that current from a selected global bit lines passes through both of the two transistors when the double gated vertically oriented select device is in the “on” condition.

10. The non-volatile storage system of claim 8 , wherein:

the first of the two gates creates channels in both of the two middle conductivity regions; and

the second of the two gates creates channels in both of the two middle conductivity regions.

11. The non-volatile storage system of claim 1 , wherein:

the double gated vertically oriented select devices include a transistor with a vertically oriented channel.

12. The non-volatile storage system of claim 1 , wherein:

the two gates are positioned between and below vertically oriented bit lines.

13. The non-volatile storage system of claim 1 , wherein:

the memory cells in combination with the vertically oriented bit lines and the word lines form a continuous mesh.

14. The non-volatile storage system of claim 1 , wherein:

the monolithic three dimensional arrangement of memory cells is an array of variable resistance memory elements.

15. The non-volatile storage system of claim 1 , further comprising:

control circuitry for operating the memory cells, active areas of the memory cells are disposed above the substrate.

16. A method of operating non-volatile storage, comprising:

providing an unselected word line voltage to unselected word lines connected to a monolithic three dimensional arrangement of memory cells positioned above and not in a substrate;

providing a selected word line voltage to a selected word line connected to the monolithic three dimensional arrangement of memory cells;

providing a data signal on a global bit line, the global bit line connected to a double gated vertically oriented select devices that is above and not in the substrate, the double gated vertically oriented select device is connected to a vertically oriented bit line and the global bit lines so that when the double gated vertically oriented select device is activated the vertically oriented bit line is in communication with the global bit line, the double gated vertically oriented select device has two gates that are offset from each other with respect to distance to the substrate with only one gate on each of two sides of the double gated vertically oriented select device so that both gates for the double gated vertically oriented select device need be at an “on” condition for the double gated vertically oriented select devices to be activated; and

activating the double gated vertically oriented select device by applying an “on” signal to both gates.

17. The method of claim 16 , wherein:

the first of the two gates is adjacent to a drain of the double gated vertically oriented select device but not adjacent to a source of the double gated vertically oriented select device and a second of the two gates is adjacent to the source of the double gated vertically oriented select device but not adjacent to the drain of the double gated vertically oriented select device.

18. The method of claim 16 , wherein:

each double gated vertically oriented select device includes two middle conductivity regions each between source/drain regions; and

a first of the two gates adjacent to a first conductivity region of the two middle conductivity regions but not adjacent to a second conductivity region of the middle conductivity regions and a second of the two gates adjacent to the second conductivity region of the middle conductivity regions but not adjacent to the first conductivity region of the middle conductivity regions.

19. The method of claim 16 , wherein:

each double gated vertically oriented select device includes two middle conductivity regions each between source/drain regions; and

both of the two gates are adjacent both of the two middle conductivity regions.

20. A non-volatile storage system, comprising:

a substrate;

a monolithic three dimensional arrangement of memory cells positioned above and not in the substrate;

a plurality of word lines connected to the memory cells;

a plurality of global bit lines;

a plurality of vertically oriented bit lines connected to the memory cells; and

a plurality of double gated vertically oriented select devices that are above and not in the substrate, the double gated vertically oriented select devices are connected to the vertically oriented bit lines and the global bit lines so that when the double gated vertically oriented select devices are activated the vertically oriented bit lines are in communication with the global bit lines, each double gated vertically oriented select device includes a source and a drain, each double gated vertically oriented select device has two gates that are offset from each other with respect to distance to the substrate with a first of the two gates adjacent to the drain but not adjacent to the source and a second of the two gates adjacent to the source but not adjacent to the drain so that both gates for the double gated vertically oriented select device need be at an “on” condition for the double gated vertically oriented select devices to be activated.

21. The non-volatile storage system of claim 20 , wherein:

the double gated vertically oriented select devices each comprise only one transistor.

22. The non-volatile storage system of claim 21 , wherein:

the one transistor includes two source/drain regions;

during a programming operation, the two gates create two channels, one channel for each gate; and

during the programming operation, the two source/drain regions are depleted and short the two channels.

23. A non-volatile storage system, comprising:

a substrate;

a monolithic three dimensional arrangement of memory cells positioned above and not in the substrate;

a plurality of word lines connected to the memory cells;

a plurality of global bit lines;

a plurality of vertically oriented bit lines connected to the memory cells; and

a plurality of double gated vertically oriented select devices that are above and not in the substrate, the double gated vertically oriented select devices are connected to the vertically oriented bit lines and the global bit lines so that when the double gated vertically oriented select devices are activated the vertically oriented bit lines are in communication with the global bit lines, each double gated vertically oriented select device includes two middle conductivity regions each between source/drain regions, each double gated vertically oriented select device has two gates that are offset from each other with respect to distance to the substrate with a first of the two gates adjacent to the a first conductivity region of the two middle conductivity regions but not adjacent to a second conductivity region of the middle conductivity regions and a second of the two gates adjacent to the second conductivity region of the middle conductivity regions but not adjacent to the first conductivity region of the middle conductivity regions so that both gates for the double gated vertically oriented select device need be at an “on” condition for the double gated vertically oriented select devices to be activated.

24. The non-volatile storage system of claim 23 , wherein:

the double gated vertically oriented select devices each comprise two transistors in series;

the first of the two gates is part of one of the two transistors;

the second of the two gates part of a second of the two transistors so that current from a selected global bit lines passes through both of the two transistors when the double gated vertically oriented select device is in the “on” condition.

25. The non-volatile storage system of claim 23 , wherein:

the first of the two gates creates a first channel in the first conductivity region of the two middle conductivity regions; and

the second of the two gates creates a second channel in the second conductivity region of the two middle conductivity regions.

26. A non-volatile storage system, comprising:

a substrate;

a monolithic three dimensional arrangement of memory cells positioned above and not in the substrate;

a plurality of word lines connected to the memory cells;

a plurality of global bit lines;

a plurality of vertically oriented bit lines connected to the memory cells; and

a plurality of double gated vertically oriented select devices that are above and not in the substrate, the double gated vertically oriented select devices are connected to the vertically oriented bit lines and the global bit lines so that when the double gated vertically oriented select devices are activated the vertically oriented bit lines are in communication with the global bit lines, each double gated vertically oriented select device includes two middle conductivity regions each between source/drain regions;

each double gated vertically oriented select device has two gates that are offset from each other with respect to distance to the substrate, are on different sides of the double gated vertically oriented select device and are adjacent both of the two middle conductivity regions.

27. The non-volatile storage system of claim 26 , wherein:

the double gated vertically oriented select devices each comprise two transistors in series;

the first of the two gates is part of one of the two transistors;

the second of the two gates part of a second of the two transistors so that current from a selected global bit lines passes through both of the two transistors when the double gated vertically oriented select device is in the “on” condition.

28. The non-volatile storage system of claim 26 , wherein:

the first of the two gates creates channels in both of the two middle conductivity regions; and

the second of the two gates creates channels in both of the two middle conductivity regions.

Assignments (7)
SECURITY AGREEMENT Recorded Apr 25, 2025
From: SANDISK TECHNOLOGIES, INC.
To: JPMORGAN CHASE BANK, N.A., AS COLLATERAL AGENT
Reel/Frame 071050/0001 →
PARTIAL RELEASE OF SECURITY INTERESTS Recorded Apr 25, 2025
From: JPMORGAN CHASE BANK, N.A., AS AGENT
To: SANDISK TECHNOLOGIES, INC.
Reel/Frame 071382/0001 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Dec 31, 2024
From: SANDISK TECHNOLOGIES LLC
To: SANDISK TECHNOLOGIES, INC.
Reel/Frame 069796/0423 →
CHANGE OF NAME Recorded May 25, 2016
From: SANDISK TECHNOLOGIES INC
To: SANDISK TECHNOLOGIES LLC
Reel/Frame 038807/0948 →
CORRECTIVE ASSIGNMENT TO CORRECT THE INCORRECT LISTED PATENT NUMBER 8853569 TO THE CORRECT PATENT NUMBER 8883569 PREVIOUSLY RECORDED ON REEL 038300 FRAME 0665. ASSIGNOR(S) HEREBY CONFIRMS THE ASSIGNMENT. Recorded Apr 25, 2016
From: SANDISK 3D LLC
To: SANDISK TECHNOLOGIES INC.
Reel/Frame 038520/0552 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Mar 30, 2016
From: SANDISK 3D LLC.
To: SANDISK TECHNOLOGIES INC.
Reel/Frame 038300/0665 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Aug 21, 2014
From: YAN, TIANHONG; SAMACHISA, GEORGE; LIU, TZ-YI; CHEN, TIM; RATNAM, PERUMAL
To: SANDISK 3D LLC
Reel/Frame 033582/0935 →
Continuity (2)
Provisional Application 61860861 · Jul 31, 2013
Related Publication 20150036414A1 · Feb 5, 2015