Magnetoresistance effect element

• US 5,549,978 A
• Filed: 11/01/1993
• Issued: 08/27/1996
• Est. Priority Date: 10/30/1992
• Status: Expired due to Term

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Ohsawa, Yuichi, Sahashi, Masashi, Iwasaki, Hitoshi, Kamiguchi, Yuzo, Hashimoto, Susumu, Sawabe, Atsuhito, Kondoh, Reiko
• Primary Examiner(s): KILIMAN, LESZEK B
• Application Number:
  US08/144,258
• Time in Patent Office: 1,030 Days
• Field of Search: 428/611, 428/622, 428/627, 428/629, 428/632, 428/639, 428/641, 428/660, 428/667, 428/670, 428/678, 428/634 R, 428/694 TR, 428/692, 428/694 T, 428/694 TS , 428/694 TM, 428/900, 360/113, 324/252
• US Class Current: 428/811.2
• 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: 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 5/3932 Magnetic biasing films
• CPC Class Codes: H01F 10/324 Exchange coupling of magnetic film pairs via a very thin non-magnetic spacer, e.g. by exchange with conduction electrons of the spacer
• CPC Class Codes: H01F 10/325 the spacer being noble metal
• 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
• CPC Class Codes: H10N 50/85 Magnetic active materials
• CPC Class Codes: Y10S 428/90 Magnetic feature
• CPC Class Codes: Y10S 428/928 Magnetic property
• CPC Class Codes: Y10T 428/1121 Multilayer
• CPC Class Codes: Y10T 428/12465 having magnetic properties, or preformed fiber orientation coordinate with shape
• CPC Class Codes: Y10T 428/12493 Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
• CPC Class Codes: Y10T 428/12542 More than one such component
• CPC Class Codes: Y10T 428/12576 Boride, carbide or nitride component
• CPC Class Codes: Y10T 428/1259 Oxide
• CPC Class Codes: Y10T 428/12611 Oxide-containing component
• CPC Class Codes: Y10T 428/1266 O, S, or organic compound in metal component
• CPC Class Codes: Y10T 428/12674 : Ge- or Si-base component
• CPC Class Codes: Y10T 428/1275 : Next to Group VIII or IB metal-base component
• CPC Class Codes: Y10T 428/12806 : Refractory [Group IVB, VB, or VIB] metal-base component
• CPC Class Codes: Y10T 428/12854 : Next to Co-, Fe-, or Ni-base component
• CPC Class Codes: Y10T 428/12861 : Group VIII or IB metal-base component
• CPC Class Codes: Y10T 428/12875 : Platinum group metal-base component
• CPC Class Codes: Y10T 428/12882 : Cu-base component alternative to Ag-, Au-, or Ni-base component
• CPC Class Codes: Y10T 428/12889 : Au-base component
• CPC Class Codes: Y10T 428/12896 : Ag-base component
• CPC Class Codes: Y10T 428/12903 : Cu-base component
• CPC Class Codes: Y10T 428/1291 : Next to Co-, Cu-, or Ni-base component
• CPC Class Codes: Y10T 428/12931 : Co-, Fe-, or Ni-base components, alternative to each other

Abstract

It is an object of the present invention to provide a magnetoresistance effect element which has a film with a spin valve structure or an artificial lattice film having good soft magnetic characteristics, and which can be applied to a high-sensitivity magnetic head. The present invention provides a magnetoresistance effect element including a stacked film formed on a substrate by sequentially stacking a ferromagnetic film containing as its main constituents at least one elements selected from the group consisting of Co, Fe, and Ni, a nonmagnetic film, and the ferromagnetic film, wherein the two ferromagnetic films are not coupled with each other, and the closest packed plane of each ferromagnetic film is oriented in a direction perpendicular to the film surface.

Claims

1. A magnetoresistance effect element comprising:

a substrate;

a stacked film formed on said substrate, and

a pair of leads to supply current to said stacked film,

said stacked film being comprised of a first ferromagnetic film, a second ferromagnetic film and a nonmagnetic film disposed between said first and second ferromagnetic films wherein said first and second ferromagnetic films are not substantially coupled with each other, a direction of magnetization of said first ferromagnetic film is pinned, said second ferromagnetic film is a field-detecting film, the magnetization of said first ferromagnetic film does not substantially rotate with lower signal magnetic fields than the magnetization of said second ferromagnetic film does, said second ferromagnetic film comprises a Co alloy having a fcc crystal structure, and a (111) plane of said stacked film is oriented in a direction perpendicular to a surface of said stacked film,

wherein said nonmagnetic film comprises Cu, Al, Pd, Pt, Rh, Ru, Ir, Au, Ag, a CuPd alloy, a CuPt alloy, a CuAu alloy or a CuNi alloy, wherein said first ferromagnetic film comprises Co, a CoFe-alloy, a CoNi alloy, a NiFe alloy, a NiFeCo alloy or Fe₈ N, and wherein said second ferromagnetic film comprises a CoFe alloy, a CoNi alloy or a NiFeCo alloy.

2. An element according to claim 1, wherein said second ferromagnetic film is made of Co_100-x Fe_x, x being 5 to 40.

3. An element according to claim 1, wherein said first and second ferromagnetic films are made of Co_100-x Fe_x, x being 5 to 40.

4. An element according to claim 1, wherein a half-width of a rocking curve is less than 20°

at a (111) plane reflection peak of an X-ray diffraction curve of said stacked film.

5. An element according to claim 1, wherein said substrate has a surface roughness of less than 5 nm.

6. An element according to claim 1, further comprising a first bias film so as to apply a first bias magnetic field to said first ferromagnetic film, and a second bias film so as to apply a second bias field to said second ferromagnetic film.

7. An element according to claim 1, further comprising an undercoating film between said substrate and said stacked film, said undercoating film having a fcc crystal structure with a larger lattice constant than those of said first and second ferromagnetic films.

8. An element according to claim 1, further comprising an undercoating film between said substrate and said stacked film, said undercoating layer comprising a magnetic amorphous material.

9. An element according to claim 2, wherein said second ferromagnetic film further comprises at least one element selected from the group consisting of Ni, Pd, Al, Cu, Ta, In, B, Nb, Hf, Mo, W, Re, Ru, Rh, Ga, Zr, It, Au, and Ag.

10. An element according to claim 6, wherein said stacked film is between said first and second bias films.

11. An element according to claim 6, wherein a direction of said first bias magnetic field is substantially perpendicular to a direction of said second bias magnetic field.

12. An element according to claim 6, wherein at least one of said first and second bias films comprises an antiferromagnetic film.

13. An element according to claim 6, wherein at least one of said first and second bias films comprises a magnetically soft film.

14. An element according to claim 7, wherein said undercoating film has an electric resistivity higher than those of said first and second ferromagnetic films.

15. An element according to claim 7, wherein said undercoating film has a resistivity of 50 μ

Ω

·

cm or more.

16. An element according to claim 7, wherein said first undercoating layer comprises NiFeX in which X is an element selected from the group consisting of Rh, Nb, Zr, Hf, Ta, Re, Ir, Pd, Pt, Cu, Mo, W, Ti, Cr, Au, and Ag.

17. A magnetoresistance effect element comprising:

a substrate;

a stacked film formed on said substrate, and

a pair of leads to supply current to said stacked film,

said stacked film being comprised of a first ferromagnetic film, a second ferromagnetic film and a nonmagnetic film disposed between said first and second ferromagnetic films wherein a thickness of said nonmagnetic film is between 0.5 nm and 20 nm, a direction of magnetization of said first ferromagnetic film is pinned, said second ferromagnetic film is a field-detecting film, the magnetization of said first ferromagnetic film does not substantially rotate with lower signal magnetic fields than the magnetization of said second ferromagnetic film does, said second ferromagnetic film comprises a Co alloy having a fcc crystal structure, and a (111) plane of said stacked film is oriented in a direction perpendicular to a surface of said stacked film,

wherein said nonmagnetic film comprises Cu, Al, Pd, Pt, Rh, Ru, Ir, Au, Ag, a CuPd alloy, a CuPt alloy, a CuAu alloy or a CuNi alloy, wherein said first ferromagnetic film comprises Co, a CoFe alloy, a CoNi alloy, a NiFe alloy, a NiFeCo alloy or FesN, and wherein said second ferromagnetic film comprises a CoFe alloy, a CoNi alloy or a NiFeCo alloy.