Patent US2188481A successfully refreshed from Google Patents.
US5485334A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetoresistive device and method having improved Barkhausen noise suppression
Assignee: PHC Corp
•
Filing: 1996-02-22
•
Granted: 1996-01-16
•
Expires: 2016-02-22
Abstract
Abstract An improved magnetoresistive device and method for fabricating the same which results in improved Barkhausen noise suppression. A generally coplanar device is described having an MR structure conductive region longitudinally biased by opposing permanent magnet layers separated therefrom by a non-magnetic metal or dielectric separation layer. significant reduction of the demagnetization energy near the MR-to-permanent magnet junction is achieved, particularly in the use of an elliptically shaped conductive region and the resultant generally coplanar device is readily fabricated and reproducible using a self-aligning process. The longitudinal bias technique described can be used in conjunction with all known transverse bias techniques.
Inventors
- 👤 James L. Nix
- 👤 Guy F. Ruse
- 👤 Paul D. Reinholz
- 👤 Anthony C. Helms
- 👤 Daniel J. O'Connor
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 15:46
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B5/33; G11B5/39; G11B5/3903; G11B5/398; H; H10; H10N; H10N50/00; H10N50/10; G11B5/399; H10N50/01; H10N50/80; H10N50/85; G11B5/31; G11B5/3109; G11B5/3116; G11B5/3163; G11B5/3906; G11B5/3929; G11B5/3932; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/4902; Y10T29/49021; Y10T29/49032; Y10T29/49036; Y10T29/49043; Y10T29/49044; Y10T29/49046
Claims Analysis
Total Claims: 48
Claim 1
Independent Claim
96 words
A magnetoresistive device comprising: a magnetoresistive structure presenting first and second oppositely disposed end portions transverse to a major axis thereof, said magnetoresistive structure comprising a magnetoresistive layer and a generally coextensive soft magnetic layer disposed in an underlying relationship thereto; and first and second permanent magnet layers disposed adjacent to, but spaced apart from, said first and second end portions of said magnetoresistive structure in a generally co-planar relationship thereto, said first and second permanent magnet layers for providing a longitudinal bias to said magnetoresistive structure while being physically separated therefrom by a separation layer.
Claim 2
Dependent Claim
96 words
A magnetoresistive device comprising: a magnetoresistive structure presenting first and second oppositely disposed end portions transverse to a major axis thereof, said magnetoresistive structure comprising a magnetoresistive layer and a generally coextensive soft magnetic layer disposed in an underlying relationship thereto; and first and second permanent magnet layers disposed adjacent to, but spaced apart from, said first and second end portions of said magnetoresistive structure in a generally co-planar relationship thereto, said first and second permanent magnet layers for providing a longitudinal bias to said magnetoresistive structure while being physically separated therefrom by a separation layer.
Claim 3
Dependent Claim
21 words
The device of claim 1 further comprising a magnetic spacing layer interposed between said magnetoresistive layer and said soft magnetic layer.
Claim 4
Dependent Claim
12 words
The device of claim 2 wherein said magnetic spacing layer comprises tantalum.
Claim 5
Dependent Claim
11 words
The device of claim 1 wherein said magnetoresistive layer comprises NiFe.
Claim 6
Dependent Claim
12 words
The device of claim 1 wherein said soft magnetic layer comprises NiFeMo.
Claim 7
Dependent Claim
18 words
The device of claim 1 further comprising first and second electrodes for providing electrical contact to said device.
Claim 8
Dependent Claim
13 words
The device of claim 6 wherein said first and second electrodes comprise Au.
Claim 9
Dependent Claim
15 words
The device of claim 6 wherein said first and second electrodes contact said magnetoresistive structure.
Claim 10
Dependent Claim
20 words
The device of claim 6 wherein said first and second electrodes contact said first and second permanent magnet layers respectively.
Claim 11
Dependent Claim
31 words
The device of claim 1 wherein separation between said first and second permanent magnet layers and said first and second end portions of said magnetoresistive structure is less than 400 angstroms.
Claim 12
Dependent Claim
22 words
The device of claim 1 wherein said first and second end portions of said magnetoresistive structure are orthogonal to said major axis.
Claim 13
Dependent Claim
34 words
The device of claim 1 wherein said first and second end portions of said magnetoresistive structure are generally defined by an ellipse having its foci generally along said major axis of said magnetoresistive structure.
Claim 14
Dependent Claim
28 words
The device of claim 1 wherein said first and second end portions of said magnetoresistive structure are curvilinearly disposed within a plane generally defined by said magnetoresistive structure.
Claim 15
Dependent Claim
22 words
The device of claim 1 wherein said first and second end portions of said magnetoresistive structure are non-orthogonal to said major axis.
Claim 16
Dependent Claim
33 words
The device of claim 1 wherein separation between said first and second permanent magnet layers and said first and second end portions of said magnetoresistive structure is defined by a nonmagnetic metal layer.
Claim 17
Dependent Claim
12 words
The device of claim 15 wherein said nonmagnetic metal layer is chromium.
Claim 18
Dependent Claim
32 words
The device of claim 1 wherein separation between said first and second permanent magnet layers and said first and second end portions of said magnetoresistive structure is defined by a dielectric material.
Claim 19
Dependent Claim
12 words
The device of claim 1 wherein said permanent magnet layers comprise CoPt.
Claim 20
Dependent Claim
68 words
A magnetoresistive device comprising: a magnetoresistive structure comprising a magnetoresistive layer and a generally coextensive soft magnetic layer disposed in an underlying relationship thereto; first and second permanent magnet layers adjacent to, but separated apart from said magnetoresistive structure, said first and second permanent magnet layers being generally co-planar with said magnetoresistive structure and providing a longitudinal bias thereto while being physically separated therefrom by a separation layer.
Claim 21
Dependent Claim
68 words
A magnetoresistive device comprising: a magnetoresistive structure comprising a magnetoresistive layer and a generally coextensive soft magnetic layer disposed in an underlying relationship thereto; first and second permanent magnet layers adjacent to, but separated apart from said magnetoresistive structure, said first and second permanent magnet layers being generally co-planar with said magnetoresistive structure and providing a longitudinal bias thereto while being physically separated therefrom by a separation layer.
Claim 22
Dependent Claim
25 words
The device of claim 19 comprising a separation between said first and second permanent magnet layers and said magnetoresistive structure of less than 400 angstroms.
Claim 23
Dependent Claim
14 words
The device of claim 20 wherein said separation is defined by a non-magnetic metal.
Claim 24
Dependent Claim
11 words
The device of claim 21 wherein said nonmagnetic metal is chromium.
Claim 25
Dependent Claim
14 words
The device of claim 19 wherein said separation is defined by a dielectric material.
Claim 26
Dependent Claim
12 words
The device of claim 23 wherein said dielectric material comprises aluminum oxide.
Claim 27
Dependent Claim
21 words
The device of claim 19 further comprising a magnetic spacing layer interposed between said magnetoresistive layer and said soft magnetic layer.
Claim 28
Dependent Claim
12 words
The device of claim 25 wherein said magnetic spacing layer comprises tantalum.
Claim 29
Dependent Claim
11 words
The device of claim 19 wherein said magnetoresistive layer comprises NiFe.
Claim 30
Dependent Claim
12 words
The device of claim 19 wherein said soft magnetic layer comprises NiFeMo.
Claim 31
Dependent Claim
12 words
The device of claim 19 wherein said permanent magnet layers comprise CoPt.
Claim 32
Dependent Claim
18 words
The device of claim 19 further comprising first and second electrodes for providing electrical contact to said device.
Claim 33
Dependent Claim
13 words
The device of claim 30 wherein said first and second electrodes comprise Au.
Claim 34
Dependent Claim
15 words
The device of claim 30 wherein said first and second electrodes contact said magnetoresistive structure.
Claim 35
Dependent Claim
20 words
The device of claim 30 wherein said first and second electrodes contact said first and second permanent magnet layers respectively.
Claim 36
Dependent Claim
27 words
The device of claim 19 wherein first and second end portions of said magnetoresistive structure transverse to a major axis thereof are orthogonal to said major axis.
Claim 37
Dependent Claim
34 words
The device of claim 19 wherein first and second end portions of said magnetoresistive structure are generally defined by an ellipse having its foci generally lying along a major axis of said magnetoresistive structure.
Claim 38
Dependent Claim
27 words
The device of claim 19 wherein first and second end portions of said magnetoresistive structure are curvilinearly disposed within a plane generally defined by said magnetoresistive structure.
Claim 39
Dependent Claim
28 words
The device of claim 19 wherein said first and second end portions of said magnetoresistive structure transverse to a major axis thereof are non-orthogonal to said major axis.
Claim 40
Dependent Claim
96 words
A magnetoresistive device comprising: a magnetoresistive conductive region comprising a magnetoresistive structure including a magnetoresistive layer and a generally coextensive soft magnetic layer disposed in an underlying relationship thereto; a separation layer adjoining opposing end portions of said conductive region; and first and second permanent magnet regions contiguous and generally co-planar with said separation layer at said end portions of said conductive region whereby said first and second permanent magnet regions provide longitudinal bias to said magnetoresistive conductive region and said separation layer spaces said first and second permanent magnet regions from said magnetoresistive conductive region.
Claim 41
Dependent Claim
96 words
A magnetoresistive device comprising: a magnetoresistive conductive region comprising a magnetoresistive structure including a magnetoresistive layer and a generally coextensive soft magnetic layer disposed in an underlying relationship thereto; a separation layer adjoining opposing end portions of said conductive region; and first and second permanent magnet regions contiguous and generally co-planar with said separation layer at said end portions of said conductive region whereby said first and second permanent magnet regions provide longitudinal bias to said magnetoresistive conductive region and said separation layer spaces said first and second permanent magnet regions from said magnetoresistive conductive region.
Claim 42
Dependent Claim
12 words
The device of claim 38 wherein said magnetoresistive conductive region comprises NiFe.
Claim 43
Dependent Claim
21 words
The device of claim 38 further comprising a magnetic spacing layer interposed between said magnetoresistive layer and said soft magnetic layer.
Claim 44
Dependent Claim
15 words
The device of claim 38 wherein said magnetoresistive conductive region is substantially elliptical in configuration.
Claim 45
Dependent Claim
13 words
The device of claim 38 wherein said separation layer comprises a non-magnetic metal.
Claim 46
Dependent Claim
11 words
The device of claim 42 wherein said nonmagnetic metal is chromium.
Claim 47
Dependent Claim
13 words
The device of claim 38 wherein said separation layer comprises a dielectric material.
Claim 48
Dependent Claim
14 words
The device of claim 38 wherein said first and second magnetic regions comprise CoPt.
References Cited (Backward Citations)
US3840898A
Cited
US4639806A
Cited
US4663685A
Cited
US4713708A
Cited
US4771349A
Cited
US4841398A
Cited
US4782414A
Cited
US4825325A
Cited
US4809109A
Cited
US4899240A
Cited
EP0375646A2
Cited
US5005096A
Cited
EP0422806A2
Cited
US5206590A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-01-15 | 1999-07-17 | 2000-01-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-01-15 | 2003-07-17 | 2004-01-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-01-15 | 2007-07-17 | 2008-01-16 | $7700.00 | Window Closed / Lapsed |