US5986858A
Expired / Lapsed
US
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Ferromagnetic tunnel-junction magnetic sensor utilizing a barrier layer having a metal layer carrying an oxide film
Assignee: Fujitsu Ltd
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Filing: 1998-03-24
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Granted: 1999-11-16
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Expires: 2018-03-24
Abstract
Abstract A ferromagnetic tunnel-junction magnetic sensor includes a first ferromagnetic layer, an insulation barrier layer formed on the first ferromagnetic layer and including therein a tunnel oxide film, and a second ferromagnetic layer formed on the insulation barrier layer, wherein the insulation barrier layer includes a metal layer carrying the tunnel oxide film thereon such that the tunnel oxide film is formed of an oxide of a metal element constituting the metal layer, and wherein the insulation barrier layer has a thickness of about 1.7 nm or less but larger than 1 molecular layer in terms of the oxide forming the tunnel oxide film.
Inventors
- 👤 Masashige Sato
- 👤 Kazuo Kobayashi
- 👤 Hideyuki Kikuchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 20:03
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/02; G01R33/06; G01R33/09; G01R33/093; G11; G11B; G11B5/00; G11B5/127; B; B82; B82Y; B82Y10/00; B82Y25/00; B82Y40/00; G01R33/098; G11B5/012; G11B5/33; G11B5/332; G11B5/39; G11B5/3903; H; H01; H01F; H01F10/00; H01F10/32; H01F10/324; H01F10/3254; H01F41/00; H01F41/14; H01F41/30; H01F41/302; H01F41/305; H01F41/307; H10; H10N; H10N50/00; H10N50/10; G11B2005/3996; G11B5/3967; H01F10/08; H01F10/10; H01F10/12; H01F10/123; H01F10/3295; Y; Y10; Y10S; Y10S148/00; Y10S148/118
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
107 words
A ferromagnetic tunnel-junction magnetic sensor, comprising: a first ferromagnetic layer; an insulation barrier layer formed on said first ferromagnetic layer, said insulation barrier layer including a tunnel oxide film; and a second ferromagnetic layer formed on said insulation barrier layer; said insulation barrier layer including a metal layer carrying said tunnel oxide film thereon, said tunnel oxide film being formed of an oxide of a metal element constituting said metal layer; said insulation barrier layer having a thickness of about 1.7 nm or less, said thickness of said insulation barrier layer being larger than 1 molecular layer in terms of said oxide forming said tunnel oxide film.
Claim 2
Dependent Claim
107 words
A ferromagnetic tunnel-junction magnetic sensor, comprising: a first ferromagnetic layer; an insulation barrier layer formed on said first ferromagnetic layer, said insulation barrier layer including a tunnel oxide film; and a second ferromagnetic layer formed on said insulation barrier layer; said insulation barrier layer including a metal layer carrying said tunnel oxide film thereon, said tunnel oxide film being formed of an oxide of a metal element constituting said metal layer; said insulation barrier layer having a thickness of about 1.7 nm or less, said thickness of said insulation barrier layer being larger than 1 molecular layer in terms of said oxide forming said tunnel oxide film.
Claim 3
Dependent Claim
26 words
A ferromagnetic tunnel-junction magnetic sensor as claimed in claim 1, wherein said metal element is selected from a group consisting of A, Hf, Zr and Nb.
Claim 4
Dependent Claim
24 words
A ferromagnetic tunnel-junction magnetic sensor as claimed in claim 1, wherein said tunnel oxide film is a native oxide film of said metal layer.
Claim 5
Dependent Claim
24 words
A ferromagnetic tunnel-junction magnetic sensor as claimed in claim 1, wherein said tunnel oxide film is a plasma oxide film of said metal layer.
Claim 6
Dependent Claim
38 words
A ferromagnetic tunnel-junction magnetic sensor as claimed in claim 1, wherein said metal layer contains oxygen with a concentration such that said concentration of oxygen increases in said metal layer toward an interface to said first ferromagnetic layer.
Claim 7
Dependent Claim
40 words
A ferromagnetic tunnel-junction magnetic sensor as claimed in claim 1, wherein said metal element has a bonding energy to oxygen larger than a bonding energy to oxygen of a metal element constituting any of said first and second ferromagnetic layers.
Claim 8
Dependent Claim
37 words
A ferromagnetic tunnel-junction magnetic sensor as claimed in claim 1, further including a diffusion barrier layer between said insulation barrier layer and said first ferromagnetic layer with a thickness allowing a substantial tunnel current to flow therethrough.
Claim 9
Dependent Claim
28 words
A ferromagnetic tunnel-junction magnetic sensor as claimed in claim 7, wherein said diffusion barrier layer is an oxide film formed on a surface of said first ferromagnetic layer.
Claim 10
Dependent Claim
44 words
A ferromagnetic tunnel-junction magnetic sensor as claimed in claim 1, wherein said insulation barrier layer includes a plurality of metal layers and a plurality of corresponding tunnel oxide films, and wherein said metal layers adjacent to each other are formed of different metal elements.
Claim 11
Dependent Claim
42 words
A ferromagnetic tunnel-junction magnetic sensor as claimed in claim 1, wherein at least one of said first and second ferromagnetic layers includes a stacking of a plurality of magnetic layers, and wherein said magnetic layers adjacent to each other have different compositions.
Claim 12
Dependent Claim
25 words
A ferromagnetic tunnel-junction magnetic sensor as claimed in claim 1, further including an anti-ferromagnetic layer adjacent to one of said first and second ferromagnetic layers.
Claim 13
Dependent Claim
31 words
A ferromagnetic tunnel-junction magnetic sensor as claimed in claim 11, wherein said anti-ferromagnetic layer includes at least two elements selected from a group consisting of Pd, Pt, Mn, Ir and Rh.
Claim 14
Dependent Claim
20 words
A ferromagnetic tunnel-junction magnetic sensor as claimed in claim 11, wherein said anti-ferromagnetic layer has a crystallographically ordered lattice structure.
Claim 15
Dependent Claim
116 words
A magnetic head including a ferromagnetic tunnel-junction magnetic sensor, said ferromagnetic tunnel-junction magnetic sensor comprising: a first ferromagnetic layer; an insulation barrier layer formed on said first ferromagnetic layer, said insulation barrier layer including a tunnel oxide film; and a second ferromagnetic layer formed on said insulation barrier layer; said insulation barrier layer including a metal layer carrying said tunnel oxide film thereon, said tunnel oxide film being formed of an oxide of a metal element constituting said metal layer; said insulation barrier layer having a thickness of about 1.7 nm or less, said thickness of said insulation barrier layer being larger than 1 molecular layer in terms of said oxide forming said tunnel oxide film.
Claim 16
Dependent Claim
116 words
A magnetic head including a ferromagnetic tunnel-junction magnetic sensor, said ferromagnetic tunnel-junction magnetic sensor comprising: a first ferromagnetic layer; an insulation barrier layer formed on said first ferromagnetic layer, said insulation barrier layer including a tunnel oxide film; and a second ferromagnetic layer formed on said insulation barrier layer; said insulation barrier layer including a metal layer carrying said tunnel oxide film thereon, said tunnel oxide film being formed of an oxide of a metal element constituting said metal layer; said insulation barrier layer having a thickness of about 1.7 nm or less, said thickness of said insulation barrier layer being larger than 1 molecular layer in terms of said oxide forming said tunnel oxide film.
Claim 17
Dependent Claim
133 words
A magnetic recording and reproducing apparatus, comprising: a magnetic recording medium; a magnetic head scanning a surface of said magnetic recording medium; said magnetic head including a ferromagnetic tunnel-junction magnetic sensor, comprising: a first ferromagnetic layer; an insulation barrier layer formed on said first ferromagnetic layer, said insulation barrier layer including a tunnel oxide film; and a second ferromagnetic layer formed on said insulation barrier layer; said insulation barrier layer including a metal layer carrying said tunnel oxide film thereon, said tunnel oxide film being formed of an oxide of a metal element constituting said metal layer; said insulation barrier layer having a thickness of about 1.7 nm or less, said thickness of said insulation barrier layer being larger than 1 molecular layer in terms of said oxide forming said tunnel oxide film.
Claim 18
Dependent Claim
133 words
A magnetic recording and reproducing apparatus, comprising: a magnetic recording medium; a magnetic head scanning a surface of said magnetic recording medium; said magnetic head including a ferromagnetic tunnel-junction magnetic sensor, comprising: a first ferromagnetic layer; an insulation barrier layer formed on said first ferromagnetic layer, said insulation barrier layer including a tunnel oxide film; and a second ferromagnetic layer formed on said insulation barrier layer; said insulation barrier layer including a metal layer carrying said tunnel oxide film thereon, said tunnel oxide film being formed of an oxide of a metal element constituting said metal layer; said insulation barrier layer having a thickness of about 1.7 nm or less, said thickness of said insulation barrier layer being larger than 1 molecular layer in terms of said oxide forming said tunnel oxide film.
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JPH09138919A
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JPH09106514A
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