Magnetoresistive effect element having magnetoresistive layer and underlying metal layer

• US 6,147,843 A
• Filed: 01/24/1997
• Issued: 11/14/2000
• Est. Priority Date: 01/26/1996
• Status: Expired due to Term

• Current Assignee: TDK Corporation
• Original Assignee: NEC Corporation
• Inventors: Nakada, Masafumi, Yamamoto, Hidefumi, Hayashi, Kazuhiko, Fujikata, Jun-Ichi, Ishihara, Kunihiko
• Primary Examiner(s): KLIMOWICZ, WILLIAM JOSEPH
• Application Number:
  US08/788,507
• Time in Patent Office: 1,390 Days
• Field of Search: 360/113, 360/313, 360/325, 360/327, 324/252, 338/32 R
• US Class Current: 360/313
• CPC Class Codes: B82Y 10/00 Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
• CPC Class Codes: B82Y 25/00 Nanomagnetism, e.g. magnetoimpedance, anisotropic magnetoresistance, giant magnetoresistance or tunneling magnetoresistance
• CPC Class Codes: G01R 33/09 Magnetoresistive devices
• CPC Class Codes: G11B 2005/3996 large or giant magnetoresistive effects [GMR], e.g. as generated in spin-valve [SV] devices
• CPC Class Codes: G11B 5/3903 using magnetic thin film layers or their effects, the films being part of integrated structures
• CPC Class Codes: G11B 5/3925 the two parts being thin films
• CPC Class Codes: G11B 5/40 Protective measures on heads, e.g. against excessive temperature G11B5/31 takes precedence; protection against wear G11B5/255 ; protective structure of the head: see under structures, e.g. G11B5/3106
• CPC Class Codes: G11B 5/455 Arrangements for functional testing of heads; Measuring arrangements for heads
• CPC Class Codes: H01F 10/3268 the exchange coupling being asymmetric, e.g. by use of additional pinning, by using antiferromagnetic or ferromagnetic coupling interface, i.e. so-called spin-valve [SV] structure, e.g. NiFe/Cu/NiFe/FeMn
• CPC Class Codes: H10N 50/10 Magnetoresistive devices

Abstract

In a magnetoresistive element, an underlying metal layer is formed on a substrate, and a magnetoresistive layer is formed on the underlying metal layer. The underlying metal layer has a thickness of about 0.1 to 3.0 nm.

Claims

1. A magnetoresistive element comprising:

an non-magnetic substrate;

an underlying metal layer formed with direct contact on said substrate, said underlying metal layer having a thickness in a range of approximately 0.1 to 3.0 nm, and being made of one of Al, Pt, Be, Cr, W and Y; and

a magnetoresistive layer formed directly on said underlying metal layer, said magnetoresistive layer having an improved crystalline orientation as compared to a magnetoresistive layer of the same material if formed without said underlying metal layer directly on said substrate.

2. The magnetoresistive element as set forth in claim 1, wherein said magnetoresistive layer comprises only a single magnetoresistive layer.

3. The magnetoresistive element as set forth in claim 2, wherein said single magnetoresistive layer is made of NiFe and is about 30 nm thick.

4. The magnetoresistive element as set forth in claim 1, wherein said magnetoresistive layer comprises at least one period comprised of a ferromagnetic layer and a nonmagnetic layer.

5. The magnetoresistive element as set forth in claim 4, wherein said ferromagnetic layer is made of one of Fe, Co, Ni and their alloys.

6. The magnetoresistive element as set forth in claim 4, wherein said ferromagnetic layer is about 1 to 30 nm thick.

7. The magnetoresistive element as set forth in claim 4, wherein said nonmagnetic layer is made of one of Cu, Au, Ag and their alloys.

8. The magnetoresistive element as set forth in claim 1, wherein said magnetoresistive layer comprises at least one period comprised of an anti-ferromagnetic layer, a first ferromagnetic layer, a nonmagnetic layer and a second ferromagnetic layer.

9. The magnetoresistive element as set forth in claim 8, wherein each of said first and second ferromagnetic layers is made of one of Fe, Co, Ni and their alloys.

10. The magnetoresistive element as set forth in claim 8, wherein each of said first and second ferromagnetic layers is about 1 to 30 nm thick.

11. The magnetoresistive element as set forth in claim 8, wherein said nonmagnetic layer is made of one of Cu, Au, Ag and their alloys.

12. The magnetoresistive element as set forth in claim 8, wherein said anti-ferromagnetic layer is made of one of FeMn, NiMn, PtMn, PdMn, NiO, CoO, NiCoO, FeO and their alloys.

13. The magnetoresistive element as set forth in claim 1, wherein said magnetoresistive layer has an FWHM of a rocking curve of less than 5°

by an X-ray diffraction measurement.