IP Library Granted Patent US 9,887,204
Granted Patent B2
US 9,887,204 · App. 15/584,371 · Granted Feb 6, 2018

Memory cells

Inventors: Kamal M. Karda (Boise, ID); Qian Tao (Boise, ID); Durai Vishak Nirmal Ramaswamy (Boise, ID); Haitao Liu (Boise, ID); Kirk D. Prall (Boise, ID); Ashonita A. Chavan (Boise, ID)
Assignee: Micron Technology, Inc.
H01L27/11502H01G4/08H01L27/10852H01L27/11507H01L28/40H01L28/75H01L27/10805
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Quick Facts
Patent No.
US 9,887,204
App. No.
15/584,371
Granted
Feb 6, 2018
Kind
B2
Abstract

A memory cell includes a select device and a capacitor electrically coupled in series with the select device. The capacitor includes two conductive capacitor electrodes having ferroelectric material there-between. The capacitor has an intrinsic current leakage path from one of the capacitor electrodes to the other through the ferroelectric material. There is a parallel current leakage path from the one capacitor electrode to the other. The parallel current leakage path is circuit-parallel the intrinsic path and of lower total resistance than the intrinsic path. Other aspects are disclosed.

Claims (46)

1. A memory cell, comprising:

a capacitor comprising:

a first conductive capacitor electrode having a base and laterally-spaced walls extending there-from;

a second conductive capacitor electrode laterally between the walls of the first capacitor electrode; and

ferroelectric material laterally between the walls of the first capacitor electrode and laterally between the second capacitor electrode and the first capacitor electrode, the capacitor comprising an intrinsic current leakage path from one of the first and second capacitor electrodes to the other through the ferroelectric material; and

a parallel current leakage path between the second capacitor electrode and a surface of the base of the first capacitor electrode, the parallel current leakage path being circuit-parallel the intrinsic current leakage path and of lower total resistance than the intrinsic current leakage path.

2. The memory cell of claim 1 wherein the parallel path where between the second capacitor electrode and the surface of the base of the first capacitor electrode is within and through material having a dominant band gap of 0.4 eV to 5.0 eV, the material having dominant band gap of 0.4 eV to 5.0 eV not being directly against lateral side surfaces of the laterally-spaced walls of the first capacitor electrode.

3. The memory cell of claim 1 wherein the parallel path where between the second capacitor electrode and the surface of the base of the first capacitor electrode is within and through material having a dominant band gap of 0.4 eV to 5.0 eV, the material having dominant band gap of 0.4 eV to 5.0 eV being directly against the surface of the base of the first capacitor electrode.

4. The memory cell of claim 3 wherein the ferroelectric material comprises laterally-spaced walls having side surfaces, the material having dominant band gap of 0.4 eV to 5.0 eV being directly against the side surfaces of the laterally-spaced walls of the ferroelectric material.

5. The memory cell of claim 1 wherein,

the ferroelectric material has a base and laterally-spaced walls extending there-from; and

the parallel path where between the second capacitor electrode and the surface of the base of the first capacitor electrode is within and through material having a dominant band gap of 0.4 eV to 5.0 eV, the material having dominant band gap of 0.4 eV to 5.0 eV extending through the base of the ferroelectric material.

6. The memory cell of claim 5 wherein the material having dominant band gap of 0.4 eV to 5.0 eV is not directly against lateral side surfaces of the laterally-spaced walls of the ferroelectric material.

7. A memory cell, comprising:

a capacitor comprising:

a first conductive capacitor electrode having laterally-spaced walls;

a second conductive capacitor electrode laterally between the walls of the first capacitor electrode; and

ferroelectric material laterally between the walls of the first capacitor electrode and laterally between the second capacitor electrode and the first capacitor electrode, the capacitor comprising an intrinsic current leakage path from one of the first and second capacitor electrodes to the other through the ferroelectric material; and

a parallel current leakage path between the second capacitor electrode and a surface of the laterally-spaced walls of the first capacitor electrode, the parallel current leakage path being circuit-parallel the intrinsic current leakage path and of lower total resistance than the intrinsic current leakage path.

8. The memory cell of claim 7 wherein the parallel path where between the second capacitor electrode and the surface of the laterally-spaced walls of the first capacitor electrode is within and through material having a dominant band gap of 0.4 eV to 5.0 eV, the material having dominant band gap of 0.4 eV to 5.0 eV comprising an annulus.

9. The memory cell of claim 7 wherein the parallel path where between the second capacitor electrode and the surface of the laterally-spaced walls of the first capacitor electrode is within and through material having a dominant band gap of 0.4 eV to 5.0 eV, the material having dominant band gap of 0.4 eV to 5.0 eV being directly against the surface of the laterally-spaced walls of the first capacitor electrode.

10. The memory cell of claim 9 wherein the surface comprises a lateral side surface of the laterally-spaced walls of the first capacitor electrode.

11. The memory cell of claim 9 wherein the first capacitor electrode has a base from which the laterally-spaced walls extend, the material having dominant band gap of 0.4 eV to 5.0 eV being directly against a surface of the base of the first capacitor electrode.

12. The memory cell of claim 9 wherein the surface comprises an elevationally outermost surface of the laterally-spaced walls of the first capacitor electrode.

13. The memory cell of claim 12 wherein the ferroelectric material comprises an elevationally outermost surface, the material having dominant band gap of 0.4 eV to 5.0 eV being directly against the elevationally outermost surface of the ferroelectric material.

14. A memory cell, comprising:

a capacitor comprising:

a first conductive capacitor electrode comprising an annulus;

a second conductive capacitor electrode radially within the annulus of the first capacitor electrode; and

ferroelectric material radially within the annulus of the first capacitor electrode between the second capacitor electrode and the first capacitor electrode, the capacitor comprising an intrinsic current leakage path from one of the first and second capacitor electrodes to the other through the ferroelectric material; and

a parallel current leakage path between the second capacitor electrode and a surface of the annulus of the first capacitor electrode, the parallel current leakage path being circuit-parallel the intrinsic current leakage path and of lower total resistance than the intrinsic current leakage path.

15. The memory cell of claim 14 wherein the parallel path where between the second capacitor electrode and the surface of the annulus of the first capacitor electrode is within and through material having a dominant band gap of 0.4 eV to 5.0 eV, the material having dominant band gap of 0.4 eV to 5.0 eV comprising an annulus.

16. The memory cell of claim 14 wherein,

the surface of the annulus is an elevationally outermost surface of the annulus; and

the parallel path where between the second capacitor electrode and the surface of the annulus of the first capacitor electrode is within and through material having a dominant band gap of 0.4 eV to 5.0 eV, the material having dominant band gap of 0.4 eV to 5.0 eV being directly against the elevationally outermost surface of the annulus.

17. The memory cell of claim 14 wherein,

the ferroelectric material comprises an annulus having an elevationally outermost surface; and

the parallel path where between the second capacitor electrode and the surface of the annulus of the first capacitor electrode is within and through material having a dominant band gap of 0.4 eV to 5.0 eV, the material having dominant band gap of 0.4 eV to 5.0 eV being directly against the elevationally outermost surface of the ferroelectric material.

18. A memory cell, comprising:

a select device;

a capacitor electrically coupled in series with the select device, the capacitor comprising:

a first conductive capacitor electrode having laterally-spaced walls extending there-from;

a second conductive capacitor electrode laterally between the walls of the first capacitor electrode; and

ferroelectric material laterally between the walls of the first capacitor electrode and laterally between the second capacitor electrode and the first capacitor electrode, the capacitor comprising an intrinsic current leakage path from one of the first and second capacitor electrodes to the other through the ferroelectric material; and

a parallel current leakage path between the second capacitor electrode and the first capacitor electrode, the parallel current leakage path being circuit-parallel the intrinsic current leakage path and of lower total resistance than the intrinsic current leakage path.

19. The memory cell of claim 18 wherein the ferroelectric material comprises laterally-spaced walls having side surfaces, the material having dominant band gap of 0.4 eV to 5.0 eV being directly against the side surfaces of the laterally-spaced walls of the ferroelectric material.

Assignments (6)
RELEASE OF SECURITY INTEREST Recorded Nov 12, 2019
From: JPMORGAN CHASE BANK, N.A., AS COLLATERAL AGENT
To: MICRON TECHNOLOGY, INC.; MICRON SEMICONDUCTOR PRODUCTS, INC.
Reel/Frame 051028/0001 →
RELEASE OF SECURITY INTEREST Recorded Oct 10, 2019
From: MORGAN STANLEY SENIOR FUNDING, INC., AS COLLATERAL AGENT
To: MICRON TECHNOLOGY, INC.
Reel/Frame 050700/0535 →
RELEASE OF SECURITY INTEREST Recorded Jul 20, 2018
From: U.S. BANK NATIONAL ASSOCIATION, AS AGENT
To: MICRON TECHNOLOGY, INC.
Reel/Frame 046597/0393 →
SECURITY INTEREST Recorded Jul 13, 2018
From: MICRON TECHNOLOGY, INC.; MICRON SEMICONDUCTOR PRODUCTS, INC.
To: JPMORGAN CHASE BANK, N.A., AS COLLATERAL AGENT
Reel/Frame 047540/0001 →
SUPPLEMENT NO. 5 TO PATENT SECURITY AGREEMENT Recorded Aug 8, 2017
From: MICRON TECHNOLOGY, INC.
To: MORGAN STANLEY SENIOR FUNDING, INC.
Reel/Frame 043482/0776 →
SUPPLEMENT NO. 5 TO PATENT SECURITY AGREEMENT Recorded Aug 8, 2017
From: MICRON TECHNOLOGY, INC.
To: U.S. BANK NATIONAL ASSOCIATION
Reel/Frame 043483/0686 →
Continuity (3)
Continuation 15064988 · Mar 9, 2016
Division 14623749 · Feb 17, 2015
Related Publication 20170236828A1 · Aug 17, 2017