Magnetoresistance effect element, its manufacturing method, magnetic reproducing element and magnetic memory

• US 6,937,447 B2
• Filed: 09/17/2002
• Issued: 08/30/2005
• Est. Priority Date: 09/19/2001
• Status: Expired due to Fees

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Kishi, Tatsuya, Haneda, Shigeru, Ohsawa, Yuichi, Kamiguchi, Yuzo, Okuno, Shiho
• Primary Examiner(s): Bernatz, Kevin M.
• Application Number:
  US10/244,550
• Publication Number:
  US 20030104249A1
• Time in Patent Office: 1,078 Days
• Field of Search: 428/611, 428/678, 428/686, 428/692, 428/693, 360/324, 360/324.1, 360/324.2
• US Class Current: 360/324.1
• 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 33/093 using multilayer structures, e.g. giant magnetoresistance sensors thin magnetic films H01F10/00
• 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 5/39 using magneto-resistive devices or effects
• CPC Class Codes: G11B 5/3929 Disposition of magnetic thin films not used for directly coupling magnetic flux from the track to the MR film or for shielding
• CPC Class Codes: G11C 11/16 using elements in which the storage effect is based on magnetic spin effect
• CPC Class Codes: G11C 11/161 details concerning the memory cell structure, e.g. the layers of the ferromagnetic memory cell
• CPC Class Codes: H10N 50/01 Manufacture or treatment
• CPC Class Codes: H10N 50/10 Magnetoresistive devices
• CPC Class Codes: Y10T 29/49043 Depositing magnetic layer or coating
• CPC Class Codes: Y10T 29/49044 Plural magnetic deposition layers
• CPC Class Codes: Y10T 428/1114 having tunnel junction effect
• CPC Class Codes: Y10T 428/1143 with defined structural feature
• CPC Class Codes: Y10T 428/12465 having magnetic properties, or preformed fiber orientation coordinate with shape
• CPC Class Codes: Y10T 428/12931 Co-, Fe-, or Ni-base components, alternative to each other
• CPC Class Codes: Y10T 428/12986 Adjacent functionally defined components
• CPC Class Codes: Y10T 428/325 Magnetic layer next to second metal compound-containing layer

Abstract

A magnetoresistance effect element includes a first ferromagnetic layer, insulating layer overlying the first ferromagnetic layer, and second ferromagnetic layer overlying the insulating layer. The insulating layer has formed a through hole having an opening width not larger than 20 nm, and the first and second ferromagnetic layers are connected to each other via the through hole.

Claims

1. A magnetoresistance effect element comprising:

a first ferromagnetic layer;

an insulating layer overlying said first ferromagnetic layer; and

a second ferromagnetic layer overlying said insulating layer,

wherein said insulating layer has a through hole penetrating its thickness direction at its predetermined position, said first ferromagnetic layer and said second ferromagnetic layer being electrically connected to each other via said through hole to form a connected portion between said first and second ferromagnetic layers, and said through hole having an opening width not larger than 20 nm,

an electric resistance between said first ferromagnetic layer and said second ferromagnetic layer changes in accordance with a change of a relative arrangement of magnetizations of said first and second ferromagnetic layers, and

an additive element which is different from elements composing said first and second ferromagnetic layers is incorporated at said connected portion between said first and second ferromagnetic layers, and a thickness of said connected portion where said additive element is incorporated is not larger than 10 atomic layers.

2. A magnetoresistance effect element according to claim 1, wherein said through hole converges toward said first ferromagnetic layer, and the converged end of said through hole defines the opening width.

3. A magnetoresistance effect element according to claim 1, wherein said insulating layer has a plurality of said through holes.

4. A magnetoresistance effect element according to claim 1, wherein said insulating layer is a polymer, or an oxide, nitride or fluoride containing at least one element selected from the group consisting of aluminum (Al), titanium (Ti), tantalum (Ta), cobalt (Co), nickel (Ni), silicon (Si), zirconium (Zr), hafnium (Hf) and iron (Fe), and

said first and second ferromagnetic layers are made of iron (Fe), cobalt (Co), nickel (Ni), or made of an alloy, an oxide, a nitride or a Heusler alloy containing at least one element selected from the group consisting of iron (Fe), cobalt (Co), nickel (Ni), manganese (Mn) and chromium (Cr), or made of a compound semiconductor or an oxide semiconductor including at least one element selected from the group consisting of iron (Fe), cobalt (Co), nickel (Ni), manganese (Mn) and chromium (Cr).

5. A magnetoresistance effect element including a plurality of the magnetoresistance effect elements according to claim 1, wherein the magnetoresistance effect elements are formed in one body and electrically connected in series.

6. A magnetoresistance effect element according to claim 1, wherein one of said first and second ferromagnetic layers is pinned in magnetization in one direction, and another of said first and second ferromagnetic layers is free in direction of magnetization.

7. A magnetic reproducing element comprising a magnetoresistance effect element including:

a first ferromagnetic layer;

an insulating layer overlying said first ferromagnetic layer; and

a second ferromagnetic layer overlying said insulating layer,

said insulating layer having a through hole penetrating its thickness direction at its predetermined position, said first ferromagnetic layer and said second ferromagnetic layer being electrically connected to each other via said through hole to form a connected portion between said first and second ferromagnetic layers, and said through hole having an opening width not larger than 20 nm,

said magnetoresistance effect element being provided on a path of the magnetic flux emitted from a magnetic recording medium so that said first and second ferromagnetic layers are serially aligned on a path of the magnetic flux emitted from a magnetic recording medium, and said magnetoresistance effect element detects a difference of a change between magnetization directions of said first and second ferromagnetic layers as a resistance change,

wherein an additive element which is different from elements composing said first and second ferromagnetic layers is incorporated at said connected portion between said first and second ferromagnetic layers, and a thickness of said connected portion where said additive element is incorporated is not larger than 10 atomic layers.

8. A magnetic reproducing element according to claim 7, wherein one of said first and second ferromagnetic layers located remoter from said magnetic recording medium is pinned in magnetization in one direction.

9. A magnetic reproducing element comprising a magnetoresistance effect element including:

a first ferromagnetic layer;

an insulating layer overlying said first ferromagnetic layer; and

a second ferromagnetic layer overlying said insulating layer,

said insulating layer having a through hole penetrating its thickness direction at its predetermined position, said first ferromagnetic layer and said second ferromagnetic layer being electrically connected to each other via said through hole to form a connected portion between said first and second ferromagnetic layers, and said through hole having an opening width not larger than 20 nm, and said magnetoresistance effect element being arranged so as to make a main plane of said first ferromagnetic layer being substantially perpendicular to a recording surface of said magnetic recording medium,

an electric resistance between said first ferromagnetic layer and said second ferromagnetic layer changing in accordance with a change of a relative arrangement of magnetizations of said first and second ferromagnetic layers,

wherein an additive element which is different from elements composing said first and second ferromagnetic layers is incorporated at said connected portion between said first and second ferromagnetic layers, and a thickness of said connected portion where said additive element is incorporated is not larger than 10 atomic layers.

10. A magnetoresistance effect element according to claim 9, wherein said through hole is out of a center of symmetry in major plane of said insulating layer toward said magnetic recording medium.

11. A magnetic memory comprising:

a magnetoresistance effect element including;

a first ferromagnetic layer being pinned in magnetization in a first direction;

an insulating layer overlying said first ferromagnetic layer;

a second ferromagnetic layer overlying said insulating layer, said second ferromagnetic layer being free in direction of magnetization, and at least one of a reading and a writing being executable by flowing a current in a direction of its layer thickness;

a nonmagnetic intermediate layer overlying said second ferromagnetic layer; and

a third ferromagnetic layer overlying said nonmagnetic intermediate layer and being pinned in magnetization in a second direction substantially opposite from said first direction,

said insulating layer having a through hole penetrating its thickness direction at its predetermined position, said first ferromagnetic layer and said second ferromagnetic layer being electrically connected to each other via said through hole to form a connected portion between said first and second ferromagnetic layers, and said through hole having an opening width not larger than 20 nm,

wherein an additive element which is different from elements composing said first and second ferromagnetic layers is incorporated at said connected portion between said first and second ferromagnetic layers, and a thickness of said connected portion where said additive element is incorporated is not larger than 10 atomic layers.

12. A magnetic memory according to claim 11, further comprising a pair of electrodes which supply said current, said electrodes partly cover a major plane of said first and second ferromagnetic layers, and said through hole being provided between said electrodes.

13. A magnetic memory according to claim 11, wherein an electric resistance between said first ferromagnetic layer and said second ferromagnetic layer changes in accordance with a change of a relative arrangement of magnetizations of said first and second ferromagnetic layers.

14. A magnetic memory comprising:

a magnetoresistance effect element including;

a first ferromagnetic layer being pinned in magnetization in a first direction;

an insulating layer overlying said first ferromagnetic layer;

a second ferromagnetic layer overlying said insulating layer, said second ferromagnetic layer being free in direction of magnetization, and at least one of a reading and a writing being executable by flowing a current in a direction of its layer thickness;

a nonmagnetic intermediate layer overlying said second ferromagnetic layer; and

a third ferromagnetic layer overlying said nonmagnetic intermediate layer and being pinned in magnetization in said first direction,

said insulating layer having a through hole penetrating its thickness direction at its predetermined position, said first ferromagnetic layer and said second ferromagnetic layer being electrically connected to each other via said through hole to form a connected portion between said first and second ferromagnetic layers, and said through hole having an opening width not larger than 20 nm,

wherein an additive element which is different from elements composing said first and second ferromagnetic layers is incorporated at said connected portion between said first and second ferromagnetic layers, and a thickness of said connected portion where said additive element is incorporated is not larger than 10 atomic layers.

15. A magnetic memory according to claim 14, further comprising a pair of electrodes which supply said current, said electrodes partly cover a major plane of said first and second ferromagnetic layers, and said through hole being provided between said electrodes.

16. A magnetic memory according to claim 14, wherein an electric resistance between said first ferromagnetic layer and said second ferromagnetic layer changes in accordance with a change of a relative arrangement of magnetizations of said first and second ferromagnetic layers.

17. A magnetic memory comprising a magnetoresistance effect element including:

a first ferromagnetic layer;

an insulating layer overlying said first ferromagnetic layer; and

a second ferromagnetic layer overlying said insulating layer,

said insulating layer having a through hole penetrating its thickness direction at its predetermined position, said first ferromagnetic layer and said second ferromagnetic layer being electrically connected to each other via said through hole to form a connected portion between said first and second ferromagnetic layers, and said through hole having an opening width not larger than 20 nm,

one of said first and second ferromagnetic layers being pinned in magnetization in a first direction,

another of said first and second ferromagnetic layers being free in direction of magnetization, and

at least one of reading and writing being executable by flowing a current in a direction of thicknesses of said first and second ferromagnetic layers,

wherein an additive element which is different from elements composing said first and second ferromagnetic layers is incorporated at said connected portion between said first and second ferromagnetic layers, and a thickness of said connected portion where said additive element is incorporated is not larger than 10 atomic layers.

18. A magnetic memory according to claim 17, further comprising a pair of electrodes which supply said current, said electrodes partly cover a major plane of said first and second ferromagnetic layers, and said through hole being provided between said electrodes.

19. A magnetic memory according to claim 17, wherein an electric resistance between said first ferromagnetic layer and said second ferromagnetic layer changes in accordance with a change of a relative arrangement of magnetizations of said first and second ferromagnetic layers.

20. A magnetic memory comprising a plurality of memory cells, said memory cells being two-dimensionally arranged, each of said memory cells being separated from each other by an insulating region, a current being provided to each of said memory cells by a conductive prove or fixed wiring, an absolute value of a writing current provided to each of said memory cells being larger than an absolute value of a reading current provided to each of said memory cells, and

each of said memory cells having a magnetoresistance effect element including:

a first ferromagnetic layer;

an insulating layer overlying said first ferromagnetic layer; and

a second ferromagnetic layer overlying said insulating layer,

said insulating layer having a through hole penetrating its thickness direction at its predetermined position, said first ferromagnetic layer and said second ferromagnetic layer being electrically connected to each other via said through hole to form a connected portion between said first and second ferromagnetic layers, and said through hole having an opening width not larger than 20 nm,

one of said first and second ferromagnetic layers being pinned in magnetization in a first direction,

another of said first and second ferromagnetic layers being free in direction of magnetization, and

said writing current and said reading current being provided in a direction of thicknesses of said first and second ferromagnetic layers,

wherein an additive element which is different from elements composing said first and second ferromagnetic layers is incorporated at said connected portion between said first and second ferromagnetic layers, and a thickness of said connected portion where said additive element is incorporated is not larger than 10 atomic layers.

21. A magnetic memory according to claim 20, wherein an electric resistance between said first ferromagnetic layer and said second ferromagnetic layer changes in accordance with a change of a relative arrangement of magnetizations of said first and second ferromagnetic layers.