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US5898612A Expired / Lapsed US ⏱️ 0.0 years remaining

Magnetic memory cell with increased GMR ratio

Assignee: NXP USA Inc
•
Filing: 1997-05-22
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Granted: 1999-04-27
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Expires: 2017-05-22
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Abstract

Abstract First and second layers of magnetic material are stacked in parallel, overlying relationship and separated by a first layer of non-magnetic material sandwiched therebetween to form a magnetic memory cell. A layer of oxide (e.g. NiO) is positioned on either one or both major surfaces of the magnetic memory cell. The oxide has a thickness (e.g. less than approximately 150 Å) which prevents the layer of oxide from pinning the first and second layers of magnetic material and adapts the layer of oxide to the first and second layers of magnetic material so as to increase the GMR ratio of the magnetic memory cell.

Inventors

  • 👤 Eugene Chen
  • 👤 Jing Shi

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-03 00:05
CPC Classifications
H; H10; H10N; H10N50/00; H10N50/10; G; G11; G11C; G11C11/00; G11C11/02; G11C11/16; G11C11/161

Claims Analysis

Total Claims: 21
Claim 1
Independent Claim 126 words
A magnetic memory device with increased GMR ratio comprising: first and second layers of magnetic material stacked in parallel, overlying relationship and separated by a first layer of non-magnetic material sandwiched therebetween so as to form a magnetic memory cell, the first layer of magnetic material having a first major surface adjacent the first layer of non-magnetic material and an opposite major surface; and a layer of an oxide of a magnetic material positioned on the second layer of magnetic material, the layer of oxide having a thickness which prevents pinning of the first and second layers of magnetic material and adapts the layer of an oxide to the first layer of magnetic material so as to increase the GMR ratio of the magnetic memory cell.
Claim 2
Dependent Claim 126 words
A magnetic memory device with increased GMR ratio comprising: first and second layers of magnetic material stacked in parallel, overlying relationship and separated by a first layer of non-magnetic material sandwiched therebetween so as to form a magnetic memory cell, the first layer of magnetic material having a first major surface adjacent the first layer of non-magnetic material and an opposite major surface; and a layer of an oxide of a magnetic material positioned on the second layer of magnetic material, the layer of oxide having a thickness which prevents pinning of the first and second layers of magnetic material and adapts the layer of an oxide to the first layer of magnetic material so as to increase the GMR ratio of the magnetic memory cell.
Claim 3
Dependent Claim 27 words
A magnetic memory device with increased GMR ratio as claimed in claim 1 wherein the thickness of the layer of oxide is less than approximately 150 Å.
Claim 4
Dependent Claim 52 words
A magnetic memory device with increased GMR ratio as claimed in claim 1 wherein the layer of oxide includes one of NiO, FeO x , CoO, Ni x Fe y O, Ni x Co y O, Co x Fe y O, Ni x Fe y Co z O, and TaO x .
Claim 5
Dependent Claim 20 words
A magnetic memory device with increased GMR ratio as claimed in claim 3 wherein the layer of oxide includes NiO.
Claim 6
Dependent Claim 34 words
A magnetic memory device with increased GMR ratio as claimed in claim 1 including in addition a supporting substrate with the layer of oxide positioned between the supporting substrate and the magnetic memory cell.
Claim 7
Dependent Claim 38 words
A magnetic memory device with increased GMR ratio as claimed in claim 1 including in addition a supporting substrate having the magnetic memory cell positioned thereon and with the layer of oxide positioned on the magnetic memory cell.
Claim 8
Dependent Claim 47 words
A magnetic memory device with increased GMR ratio as claimed in claim 1 including in addition a supporting substrate with the layer of oxide positioned between the supporting substrate and the magnetic memory cell and with an another layer of oxide positioned on the magnetic memory cell.
Claim 9
Dependent Claim 122 words
A magnetic memory device with increased GMR ratio comprising: a layer of an oxide of a magnetic material with a thickness less than approximately 150 Å; and first and second layers of magnetic material stacked in parallel, overlying relationship on the layer of oxide and separated by a layer of non-magnetic material sandwiched between the first and second layers of magnetic material so as to form a magnetic memory cell; the layer of oxide having the thickness which prevents the layer of an oxide from pinning the first and second layers of magnetic material and adapts the layer of an oxide to the first and second layers of magnetic material so as to increase the GMR ratio of the magnetic memory cell.
Claim 10
Dependent Claim 122 words
A magnetic memory device with increased GMR ratio comprising: a layer of an oxide of a magnetic material with a thickness less than approximately 150 Å; and first and second layers of magnetic material stacked in parallel, overlying relationship on the layer of oxide and separated by a layer of non-magnetic material sandwiched between the first and second layers of magnetic material so as to form a magnetic memory cell; the layer of oxide having the thickness which prevents the layer of an oxide from pinning the first and second layers of magnetic material and adapts the layer of an oxide to the first and second layers of magnetic material so as to increase the GMR ratio of the magnetic memory cell.
Claim 11
Dependent Claim 52 words
A magnetic memory device with increased GMR ratio as claimed in claim 8 wherein the layer of oxide includes one of NiO, FeO x , CoO, Ni x Fe y O, Ni x Co y O, Co x Fe y O, Ni x Fe y Co z O, and TaO x .
Claim 12
Dependent Claim 20 words
A magnetic memory device with increased GMR ratio as claimed in claim 9 wherein the layer of oxide includes NiO.
Claim 13
Dependent Claim 34 words
A magnetic memory device with increased GMR ratio as claimed in claim 8 including in addition a supporting substrate with the layer of oxide positioned between the supporting substrate and the magnetic memory cell.
Claim 14
Dependent Claim 38 words
A magnetic memory device with increased GMR ratio as claimed in claim 8 including in addition a supporting substrate having the magnetic memory cell positioned thereon and with the layer of oxide positioned on the magnetic memory cell.
Claim 15
Dependent Claim 47 words
A magnetic memory device with increased GMR ratio as claimed in claim 8 including in addition a supporting substrate with the layer of oxide positioned between the supporting substrate and the magnetic memory cell and with an another layer of oxide positioned on the magnetic memory cell.
Claim 16
Dependent Claim 192 words
A magnetic memory device with increased GMR ratio comprising: a support substrate; a layer of an oxide of a magnetic material formed on a surface of the supporting substrate with a thickness less than approximately 150 Å; first and second layers of magnetic stacked in parallel, overlying relationship on the layer of an oxide of a magnetic material and separated by a layer of non-magnetic material sandwiched between the first and second layers of magnetic material so as to form a magnetic memory cell having a length and a width; the width of the magnetic memory cell being less than a width of magnetic domain walls within the first and second layers of magnetic material wherein magnetic vectors in the first and second layers of magnetic material point substantially along a length of the first and second layers of magnetic material; and the layer of oxide having the thickness which prevents the layer of oxide from pinning the first and second layers of magnetic material and adapts the layer of oxide to the first and second layers of magnetic material so as to increase the GMR ratio of the magnetic memory cell.
Claim 17
Dependent Claim 192 words
A magnetic memory device with increased GMR ratio comprising: a support substrate; a layer of an oxide of a magnetic material formed on a surface of the supporting substrate with a thickness less than approximately 150 Å; first and second layers of magnetic stacked in parallel, overlying relationship on the layer of an oxide of a magnetic material and separated by a layer of non-magnetic material sandwiched between the first and second layers of magnetic material so as to form a magnetic memory cell having a length and a width; the width of the magnetic memory cell being less than a width of magnetic domain walls within the first and second layers of magnetic material wherein magnetic vectors in the first and second layers of magnetic material point substantially along a length of the first and second layers of magnetic material; and the layer of oxide having the thickness which prevents the layer of oxide from pinning the first and second layers of magnetic material and adapts the layer of oxide to the first and second layers of magnetic material so as to increase the GMR ratio of the magnetic memory cell.
Claim 18
Dependent Claim 52 words
A magnetic memory device with increased GMR ratio as claimed in claim 14 wherein the layer of oxide includes one of NiO, FeO x , CoO, Ni x Fe y O, Ni x Co y O, Co x Fe y O, Ni x Fe y Co z O, and TaO x .
Claim 19
Dependent Claim 20 words
A magnetic memory device with increased GMR ratio as claimed in claim 15 wherein the layer of oxide includes NiO.
Claim 20
Dependent Claim 39 words
A magnetic memory device with increased GMR ratio as claimed in claim 14 wherein the non-magnetic material sandwiched between the first and second layers of magnetic material includes one of an electrically conductive material and an electrically insulating material.
Claim 21
Dependent Claim 28 words
A magnetic memory device with increased GMR ratio as claimed in claim 14 including in addition an another layer of an oxide positioned on the magnetic memory cell.

References Cited (Backward Citations)

US5636159A Cited
US5459687A Cited
US5659499A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 2002-04-26 2002-10-26 2003-04-27 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2006-04-26 2006-10-26 2007-04-27 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2010-04-26 2010-10-26 2011-04-27 $7700.00 Window Closed / Lapsed

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