US5748524A
Expired / Lapsed
US
⏱️ 0.0 years remaining
MRAM with pinned ends
Assignee: NXP USA Inc
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Filing: 1996-09-23
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Granted: 1998-05-05
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Expires: 2016-09-23
Abstract
Abstract A multi-layer magnetic memory cell is provided, with magnetic end vectors adjacent the ends of the cell pinned in a fixed direction. To pin the magnetic end vectors, a magnetic field is applied to an end of at least one of the layers of magnetic material in the cell to move the magnetic end vectors in the magnetic material at the end of the cell into a fixed direction. Pinning material is then disposed adjacent to the end to maintain the magnetic end vectors in the magnetic material at the end of the cell in the fixed direction.
Inventors
- 👤 Eugene Chen
- 👤 Saied N. Tehrani
- 👤 Ronald N. Legge
- 👤 Xiaodong T. Zhu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 18:09
CPC Classifications
G; G11; G11C; G11C11/00; G11C11/56; G11C11/5607; G11C11/02; G11C11/14; G11C11/15; G11C11/16; G11C11/161; G11C11/165; G11C11/1675; G11C2211/00; G11C2211/56; G11C2211/561; G11C2211/5616
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
67 words
In a magnetic memory cell a layer of magnetic material having a width and a length so as to define opposed ends generally parallel to the width adjacent opposed extremities of the length and means positioned adjacent to at least one of the ends of the layer of magnetic material to pin magnetic end vectors in the magnetic material at the one end in a fixed direction.
Claim 2
Dependent Claim
67 words
In a magnetic memory cell a layer of magnetic material having a width and a length so as to define opposed ends generally parallel to the width adjacent opposed extremities of the length and means positioned adjacent to at least one of the ends of the layer of magnetic material to pin magnetic end vectors in the magnetic material at the one end in a fixed direction.
Claim 3
Dependent Claim
32 words
In a magnetic memory cell a layer of magnetic material as claimed in claim 1 wherein the means positioned adjacent to the at least one end includes a layer of antiferromagnetic material.
Claim 4
Dependent Claim
35 words
In a magnetic memory cell a layer of magnetic material as claimed in claim 1 wherein the means positioned adjacent to the at least one end includes a layer of hard or permanent magnetic material.
Claim 5
Dependent Claim
51 words
In a magnetic memory cell a layer of magnetic material as claimed in claim 1 wherein the layer of magnetic material includes a thickness that is tapered at the at least one end to form a surface and the means is positioned on the surface at the at least one end.
Claim 6
Dependent Claim
63 words
In a magnetic memory cell a layer of magnetic material as claimed in claim 1 wherein the layer of magnetic material has a width less than a width of magnetic domain walls within the layer of magnetic material so as to restrict major magnetic vectors in the layer of magnetic material to point substantially along the length of the layer of magnetic material.
Claim 7
Dependent Claim
149 words
A multi-layer, magnetic memory cell comprising: a first layer of magnetic material; a layer of nonmagnetic material positioned on the first layer of magnetic material; a second layer of magnetic material positioned on the layer of nonmagnetic material so as to form a magnetic memory cell; the magnetic memory cell having a width and a length so as to define opposed ends generally parallel to the width adjacent opposed extremities of the length, with the width being less than a width of magnetic domain walls within the layers of magnetic material so as to restrict major magnetic vectors in the layers of magnetic material to point substantially along the length of the layers of magnetic material; and means positioned adjacent to at least one of the ends of the magnetic memory cell to pin magnetic end vectors in the magnetic material at the one end in a fixed direction.
Claim 8
Dependent Claim
149 words
A multi-layer, magnetic memory cell comprising: a first layer of magnetic material; a layer of nonmagnetic material positioned on the first layer of magnetic material; a second layer of magnetic material positioned on the layer of nonmagnetic material so as to form a magnetic memory cell; the magnetic memory cell having a width and a length so as to define opposed ends generally parallel to the width adjacent opposed extremities of the length, with the width being less than a width of magnetic domain walls within the layers of magnetic material so as to restrict major magnetic vectors in the layers of magnetic material to point substantially along the length of the layers of magnetic material; and means positioned adjacent to at least one of the ends of the magnetic memory cell to pin magnetic end vectors in the magnetic material at the one end in a fixed direction.
Claim 9
Dependent Claim
60 words
A multi-layer, magnetic memory cell as claimed in claim 6 wherein the means positioned adjacent to the at least one end of the magnetic memory includes pinning material positioned on one of the first and second layers of magnetic material adjacent the end to maintain the magnetic end vectors in the magnetic material at the end in the fixed direction.
Claim 10
Dependent Claim
27 words
A multi-layer, magnetic memory cell as claimed in claim 7 wherein the means positioned adjacent to the at least one end includes a layer of antiferromagnetic material.
Claim 11
Dependent Claim
30 words
A multi-layer, magnetic memory cell as claimed in claim 7 wherein the means positioned adjacent to the at least one end includes a layer of hard or permanent magnetic material.
Claim 12
Dependent Claim
45 words
A multi-layer, magnetic memory cell as claimed in claim 7 wherein the magnetic memory cell includes a thickness that is tapered at the at least one end to form a surface and the means is positioned on the surface at the at least one end.
Claim 13
Dependent Claim
35 words
A multi-layer, magnetic memory cell as claimed in claim 7 wherein the layer of nonmagnetic material includes a layer of electrically conductive material and the first and second layers of magnetic material are ferromagnetically coupled.
Claim 14
Dependent Claim
160 words
A process for pinning magnetic vectors adjacent an end of a layer of magnetic material having a width and a length, comprising the steps of: providing a layer of magnetic material having a width and a length so as to define opposed ends generally parallel to the width adjacent opposed extremities of the length, the width of the layer of magnetic material being less than a width of magnetic domain walls within the layer of magnetic material so as to restrict major magnetic vectors in the layer of magnetic material to point substantially along the length of the layer of magnetic material; applying a magnetic field to one of the ends of the layer of magnetic material to move magnetic end vectors in the magnetic material at the one end into a fixed direction; and disposing pinning material adjacent the one end to maintain the magnetic end vectors in the magnetic material at the one end in the fixed direction.
Claim 15
Dependent Claim
160 words
A process for pinning magnetic vectors adjacent an end of a layer of magnetic material having a width and a length, comprising the steps of: providing a layer of magnetic material having a width and a length so as to define opposed ends generally parallel to the width adjacent opposed extremities of the length, the width of the layer of magnetic material being less than a width of magnetic domain walls within the layer of magnetic material so as to restrict major magnetic vectors in the layer of magnetic material to point substantially along the length of the layer of magnetic material; applying a magnetic field to one of the ends of the layer of magnetic material to move magnetic end vectors in the magnetic material at the one end into a fixed direction; and disposing pinning material adjacent the one end to maintain the magnetic end vectors in the magnetic material at the one end in the fixed direction.
Claim 16
Dependent Claim
40 words
A process for pinning magnetic vectors adjacent the end of a layer of magnetic material as claimed in claim 12 wherein the step of disposing pinning material adjacent the end includes disposing a layer of antiferromagnetic material adjacent the end.
Claim 17
Dependent Claim
43 words
A process for pinning magnetic vectors adjacent the end of a layer of magnetic material as claimed in claim 12 wherein the step of disposing pinning material adjacent the end includes disposing a layer of hard or permanent magnetic material adjacent the end.
Claim 18
Dependent Claim
55 words
A process for pinning magnetic vectors adjacent the end of a layer of magnetic material as claimed in claim 12 wherein the step of disposing pinning material adjacent the end includes tapering the at least one end to form a surface and positioning the pinning material on the surface at the at least one end.
Claim 19
Dependent Claim
43 words
A process for pinning magnetic vectors adjacent the end of a layer of magnetic material as claimed in claim 12 wherein the step of providing a layer of magnetic material includes disposing the layer of magnetic material in a multi-layer magnetic memory cell.
References Cited (Backward Citations)
US3479156A
Cited
US3553660A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-05-04 | 2001-11-03 | 2002-05-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-05-04 | 2005-11-03 | 2006-05-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-05-04 | 2009-11-03 | 2010-05-05 | $7700.00 | Window Closed / Lapsed |