US4914538A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetoresistive read transducer
Assignee: International Business Machines Corp
•
Filing: 1988-08-18
•
Granted: 1990-04-03
•
Expires: 2008-08-18
Abstract
Abstract A magnetoresistive sensor having spaced electrically conductive lead structures comprising a thin film of tungsten having a thin film overlayer, or, alternatively a thin film underlayer and a thin film overlayer, with both the thin film underlayer and the thin film overlayer formed of a material taken from the groups consisting of Ti, Ta, Cr, Zr, Hf, and TiW.
Inventors
- 👤 James K. Howard
- 👤 Hung-Chang W. Huang
- 👤 Cherngye Hwang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 11:04
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B5/33; G11B5/39; G11B5/3903
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
135 words
A magnetoresistive sensor comprising; a thin film of magnetoresistive material; a plurality of electrically conductive lead structures, each of said electrically conductive lead structures electrically contacting said thin film of magnetoresistive material at spaced positions, said electrically conductive lead structures comprising a thin film of tungsten in contact with said thin film of magnetoresistive material and a thin film overlayer formed of a material taken from the group consisting of titanium, chromium, tantalum, zirconium, hafnium and a titanium-tungsten alloy, said thin film of tungsten and said overlayer being coextensive in said lead structures, whereby, when a signal output means is connected between two of said electrically conductive lead structures, the resistance changes in said magnetoresistive material can be detected as a function of the fields which are intercepted by said thin film of magnetoresistive material.
Claim 2
Dependent Claim
135 words
A magnetoresistive sensor comprising; a thin film of magnetoresistive material; a plurality of electrically conductive lead structures, each of said electrically conductive lead structures electrically contacting said thin film of magnetoresistive material at spaced positions, said electrically conductive lead structures comprising a thin film of tungsten in contact with said thin film of magnetoresistive material and a thin film overlayer formed of a material taken from the group consisting of titanium, chromium, tantalum, zirconium, hafnium and a titanium-tungsten alloy, said thin film of tungsten and said overlayer being coextensive in said lead structures, whereby, when a signal output means is connected between two of said electrically conductive lead structures, the resistance changes in said magnetoresistive material can be detected as a function of the fields which are intercepted by said thin film of magnetoresistive material.
Claim 3
Dependent Claim
25 words
The magnetoresistive sensor of claim 1 wherein said thin film overlayer is formed of a material taken from the group consisting of tantalum and titanium.
Claim 4
Dependent Claim
25 words
The magnetoresistive sensor of claim 2 wherein said thin film of tungsten is 1000-5000 angstroms thick and said thin film overlayer is 25-200 angstroms thick.
Claim 5
Dependent Claim
152 words
A magnetoresistive sensor comprising; a thin film of magnetoresistive material; a plurality of electrically conductive lead structures, each of said electrically conductive lead structures electrically contacting said thin film of magnetoresistive material at spaced position, said electrically conductive lead structures comprising a thin film of tungsten, a thin film underlayer in contact with said thin film of magnetoresistive material and a thin film overlayer, both said thin film underlayer and said thin film overlayer being formed of a material taken from the group consisting of titanium, chromium, tantalum, zirconium, hafnium and a titanium-tungsten alloy said thin film of tungsten, said underlayer, and said overlayer being coextensive in said lead structures, whereby, when a signal output means is connected between two of said electrically conductive lead structures, the resistance changes in said magnetoresistive material can be detected as a function of the fields which are intercepted by said thin film of magnetoresistive material.
Claim 6
Dependent Claim
152 words
A magnetoresistive sensor comprising; a thin film of magnetoresistive material; a plurality of electrically conductive lead structures, each of said electrically conductive lead structures electrically contacting said thin film of magnetoresistive material at spaced position, said electrically conductive lead structures comprising a thin film of tungsten, a thin film underlayer in contact with said thin film of magnetoresistive material and a thin film overlayer, both said thin film underlayer and said thin film overlayer being formed of a material taken from the group consisting of titanium, chromium, tantalum, zirconium, hafnium and a titanium-tungsten alloy said thin film of tungsten, said underlayer, and said overlayer being coextensive in said lead structures, whereby, when a signal output means is connected between two of said electrically conductive lead structures, the resistance changes in said magnetoresistive material can be detected as a function of the fields which are intercepted by said thin film of magnetoresistive material.
Claim 7
Dependent Claim
25 words
The magnetoresistive sensor of claim 4 wherein said thin film overlayer is formed of a material taken from the group consisting of tantalum and titanium.
Claim 8
Dependent Claim
25 words
The magnetoresistive sensor of claim 5 wherein said thin film of tungsten is 1000-5000 angstroms thick and said thin film overlayer is 25-2000 angstroms thick.
References Cited (Backward Citations)
US3967368A
Cited
JPS5267312A
Cited
US4503394A
Cited
US4622613A
Cited
US4663684A
Cited
US4807073A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-04-02 | 1993-10-02 | 1994-04-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-04-02 | 1997-10-02 | 1998-04-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-04-02 | 2001-10-02 | 2002-04-03 | $7700.00 | Window Closed / Lapsed |