Patent US6417561B1 successfully refreshed from Google Patents.
US6417561B1
Expired / Lapsed
US
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Keepers for MRAM electrodes
Assignee: Micron Technology Inc
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Filing: 2001-07-27
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Granted: 2002-07-09
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Expires: 2021-07-27
Abstract
Abstract A magnetic memory device, preferably a magnetic random access memory (MRAM) and method for forming same are described wherein a bit region sensitive to magnetic fields and preferably comprising a tunneling magnetoresistance (TMR) structure is located between a top electrode with a magnetic keeper and a bottom electrode with a magnetic keeper. The top electrode is preferably made of copper using a damascene process. The magnetic keeper of the top electrode includes at least a magnetic material layer (e.g., Co—Fe) but in the illustrated embodiments also includes one or more barrier layer (e.g., Ta). Various embodiments describe structures wherein the magnetic keeper stack is in contact with one, two or three surfaces of the top electrode, which face outward from the device.
Inventors
- 👤 Mark E. Tuttle
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 04:34
CPC Classifications
H; H10; H10B; H10B61/00; G; G11; G11C; G11C11/00; G11C11/02; G11C11/14; G11C11/15; B; B82; B82Y; B82Y10/00; H10N; H10N50/00; H10N50/01
Claims Analysis
Total Claims: 45
Claim 1
Independent Claim
96 words
A magnetic memory device in an integrated circuit, comprising: a bottom electrode over a semiconductor substrate; a bit region sensitive to magnetic fields, over the bottom electrode; a damascene trench in an insulating layer; a barrier material that lines the damascene trench; an upper electrode disposed in the damascene trench having a bottom surface facing toward the bit region, a top surface facing away from the bit region, and two side surfaces; and a magnetic keeper disposed at least between the barrier metal that lines the damascene trench and the side surfaces of the upper electrode.
Claim 2
Dependent Claim
96 words
A magnetic memory device in an integrated circuit, comprising: a bottom electrode over a semiconductor substrate; a bit region sensitive to magnetic fields, over the bottom electrode; a damascene trench in an insulating layer; a barrier material that lines the damascene trench; an upper electrode disposed in the damascene trench having a bottom surface facing toward the bit region, a top surface facing away from the bit region, and two side surfaces; and a magnetic keeper disposed at least between the barrier metal that lines the damascene trench and the side surfaces of the upper electrode.
Claim 3
Dependent Claim
27 words
The magnetic memory device of claim 1 wherein a top surface of the bit region is in electrical contact with the upper electrode in the damascene trench.
Claim 4
Dependent Claim
13 words
The magnetic memory device of claim 2 wherein the upper electrode comprises copper.
Claim 5
Dependent Claim
23 words
The magnetic memory device of claim 2 wherein the magnetic keeper comprises multiple stacked layers including at least one layer of magnetic material.
Claim 6
Dependent Claim
13 words
The magnetic memory device of claim 4 wherein the barrier material comprises tantalum.
Claim 7
Dependent Claim
46 words
The magnetic memory device of claim 4 wherein the barrier material comprises a first tantalum layer and the multiple stacked layers comprise a second tantalum layer and a Co—Fe layer, where the Co—Fe layer is disposed between the first tantalum layer and the second tantalum layer.
Claim 8
Dependent Claim
13 words
The magnetic memory device of claim 1 wherein the barrier material comprises tantalum.
Claim 9
Dependent Claim
33 words
The magnetic memory device of claim 1 wherein a portion of the magnetic keeper lies over the insulating layer and is in contact at least with the top surface of the upper electrode.
Claim 10
Dependent Claim
19 words
The magnetic memory device of claim 8 wherein the magnetic keeper contains holes over vias in the insulating layer.
Claim 11
Dependent Claim
22 words
The magnetic memory device of claim 1 wherein the magnetic keeper is in contact with the top surface of the upper electrode.
Claim 12
Dependent Claim
76 words
A magnetic keeper for a top conductor of a magnetic random access memory (MRAM) device, the top conductor having a bottom structure facing toward an underlying magnetic storage element, the magnetic keeper comprising a magnetic layer extending along sidewalls of the top conductor and a barrier layer between a surrounding insulating layer and the magnetic layer, wherein the barrier layer also intervenes between a bottom edge of the magnetic layer and the underlying magnetic storage element.
Claim 13
Dependent Claim
76 words
A magnetic keeper for a top conductor of a magnetic random access memory (MRAM) device, the top conductor having a bottom structure facing toward an underlying magnetic storage element, the magnetic keeper comprising a magnetic layer extending along sidewalls of the top conductor and a barrier layer between a surrounding insulating layer and the magnetic layer, wherein the barrier layer also intervenes between a bottom edge of the magnetic layer and the underlying magnetic storage element.
Claim 14
Dependent Claim
41 words
The magnetic keeper of claim 11 wherein the underlying magnetic storage element comprises a tunneling magneto resistance (TMR) bit structure, and a top surface of the TMR bit structure is in electrical contact with a bottom surface of the top conductor.
Claim 15
Dependent Claim
18 words
The magnetic keeper of claim 11 wherein the top conductor comprises conductive word line in a damascene trench.
Claim 16
Dependent Claim
12 words
The magnetic keeper of claim 13 wherein the top conductor comprises copper.
Claim 17
Dependent Claim
20 words
The magnetic keeper of claim 13 wherein a depth of the damascene trench is between about 100 and 300 nm.
Claim 18
Dependent Claim
20 words
The magnetic keeper of claim 15 wherein the depth of the damascene trench is between about 180 and 220 nm.
Claim 19
Dependent Claim
20 words
The magnetic keeper of claim 15 wherein a width of the damascene trench is between about 100 and 300 nm.
Claim 20
Dependent Claim
20 words
The magnetic keeper of claim 17 wherein the width of the damascene trench is between about 180 and 220 nm.
Claim 21
Dependent Claim
18 words
The magnetic keeper of claim 11 wherein the barrier layer comprises tantalum, and the magnetic layer comprises cobalt-iron.
Claim 22
Dependent Claim
23 words
The magnetic keeper of claim 19 wherein the barrier layer and the magnetic layer are each between about 1 and 20 nm thick.
Claim 23
Dependent Claim
23 words
The magnetic keeper of claim 20 wherein the barrier layer and the magnetic layer are each between about 2 and 10 nm thick.
Claim 24
Dependent Claim
37 words
The magnetic keeper of claim 11 further comprising a magnetic layer along a top surface of the top conductor, the top surface facing away from the magnetic storage element, and a barrier layer over the magnetic layer.
Claim 25
Dependent Claim
122 words
A top conductor in a trench in an insulating layer over a magnetic memory device comprising: a magnetic material lining layer along each sidewall of the trench; a top surface of the lining layer sloping downward from an outer edge of the lining layer that is no higher than a top surface of the insulating layer toward an inner edge of the lining layer; conducting material filling the trench; and a magnetic material top layer across a top surface of the conducting material and in contact with the top surface of the magnetic material lining layer along each sidewall of the trench, an upper surface of the magnetic material top layer extending no higher than the top surface of the insulating layer.
Claim 26
Dependent Claim
122 words
A top conductor in a trench in an insulating layer over a magnetic memory device comprising: a magnetic material lining layer along each sidewall of the trench; a top surface of the lining layer sloping downward from an outer edge of the lining layer that is no higher than a top surface of the insulating layer toward an inner edge of the lining layer; conducting material filling the trench; and a magnetic material top layer across a top surface of the conducting material and in contact with the top surface of the magnetic material lining layer along each sidewall of the trench, an upper surface of the magnetic material top layer extending no higher than the top surface of the insulating layer.
Claim 27
Dependent Claim
29 words
The top conductor of claim 23 wherein the top surface of the outer edge of the lining layer is approximately even with the top surface of the insulating layer.
Claim 28
Dependent Claim
46 words
The top conductor of claim 23 further comprising the conducting material covering the top surface of the lining layer along each sidewall of the trench, thereby forming an approximately flat upper surface that is continuous and approximately coplanar with the top surface of the insulating layer.
Claim 29
Dependent Claim
72 words
The top conductor of claim 23 further comprising a first barrier layer between the magnetic material lining layer and each sidewall of the trench, a top surface of the first barrier layer sloping downward from an outer edge of the first barrier layer that is approximately even with the top surface of the insulating layer to an inner edge that is approximately even with the top surface of the magnetic lining layer.
Claim 30
Dependent Claim
65 words
The top conductor of claim 26 further comprising a second barrier layer between the magnetic material lining layer and the conducting material, a top surface of the second barrier layer sloping downward from an outer edge of the second barrier layer that is approximately even with the top surface of the inner edge of the lining layer toward an inner edge of the barrier layer.
Claim 31
Dependent Claim
32 words
The top conductor of claim 23 wherein the magnetic material top layer forms an approximately flat upper surface that is continuous and approximately coplanar with the top surface of the insulating layer.
Claim 32
Dependent Claim
52 words
The top conductor of claim 23 wherein a top barrier layer is in contact with at least a central portion of the upper surface of the magnetic material top layer, the top barrier layer having an approximately flat upper surface that is approximately coplanar with the top surface of the insulating layer.
Claim 33
Dependent Claim
96 words
A magnetic memory device in a magnetic random access memory (MRAM) comprising: a bottom electrode over a semiconductor substrate; a bit region sensitive to magnetic fields, where the bit region is formed over the bottom electrode; a damascene trench in an insulating layer; an upper electrode with a bottom surface, a top surface, and two side surfaces, where the upper electrode is disposed in the damascene trench such that the bottom surface faces the bit region; a recess defined in the top surface of the upper electrode; and a first magnetic keeper disposed in the recess.
Claim 34
Dependent Claim
96 words
A magnetic memory device in a magnetic random access memory (MRAM) comprising: a bottom electrode over a semiconductor substrate; a bit region sensitive to magnetic fields, where the bit region is formed over the bottom electrode; a damascene trench in an insulating layer; an upper electrode with a bottom surface, a top surface, and two side surfaces, where the upper electrode is disposed in the damascene trench such that the bottom surface faces the bit region; a recess defined in the top surface of the upper electrode; and a first magnetic keeper disposed in the recess.
Claim 35
Dependent Claim
28 words
The magnetic memory device as defined in claim 30 , further comprising a second magnetic keeper disposed between the sides of the upper electrode and the damascene trench.
Claim 36
Dependent Claim
21 words
The magnetic memory device as defined in claim 30 , wherein the bit region corresponds to a giant magentoresistance (GMR) structure.
Claim 37
Dependent Claim
21 words
The magnetic memory device as defined in claim 30 , wherein the bit region corresponds to a tunneling magentoresistance (TMR) structure.
Claim 38
Dependent Claim
22 words
The magnetic memory device as defined in claim 30 , wherein the recess is between about 5 and 100 nm in depth.
Claim 39
Dependent Claim
22 words
The magnetic memory device as defined in claim 30 , wherein the recess is between about 10 and 30 nm in depth.
Claim 40
Dependent Claim
19 words
The magnetic memory device as defined in claim 30 , wherein the first magnetic keeper comprises a magnetic material.
Claim 41
Dependent Claim
31 words
The magnetic memory device as defined in claim 30 , wherein the first magnetic keeper comprises a multiple layer stack of a barrier material, a magnetic material, and the barrier material.
Claim 42
Dependent Claim
126 words
A magnetic memory device with a magnetic keeper in a magnetic random access memory (MRAM) comprising: a bottom electrode over a semiconductor substrate; a bit region sensitive to magnetic fields, where the bit region is formed over the bottom electrode; a damascene trench in an insulating layer; an upper electrode with a bottom surface, a top surface, and two side surfaces, where the upper electrode is disposed in the damascene trench such that the bottom surface faces the bit region; a first portion of the magnetic keeper formed on sidewalls of the damascene trench; and a second portion of the magnetic keeper formed on the top surface of the upper electrode such that at least part of the second portion is formed below the first portion.
Claim 43
Dependent Claim
126 words
A magnetic memory device with a magnetic keeper in a magnetic random access memory (MRAM) comprising: a bottom electrode over a semiconductor substrate; a bit region sensitive to magnetic fields, where the bit region is formed over the bottom electrode; a damascene trench in an insulating layer; an upper electrode with a bottom surface, a top surface, and two side surfaces, where the upper electrode is disposed in the damascene trench such that the bottom surface faces the bit region; a first portion of the magnetic keeper formed on sidewalls of the damascene trench; and a second portion of the magnetic keeper formed on the top surface of the upper electrode such that at least part of the second portion is formed below the first portion.
Claim 44
Dependent Claim
26 words
The magnetic memory device as defined in claim 38 , wherein the first portion and the second portion of the magnetic keeper comprise a magnetic material.
Claim 45
Dependent Claim
41 words
The magnetic memory device as defined in claim 38 , wherein at least one of the first portion and the second portion of magnetic keeper comprises a multiple layer stack of a barrier material, a magnetic material, and the barrier material.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2005-07-08 | 2006-01-07 | 2006-07-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2009-07-08 | 2010-01-07 | 2010-07-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2013-07-08 | 2014-01-07 | 2014-07-09 | $7700.00 | Window Closed / Lapsed |