Magnetoresistive element, method for manufacturing the same, and magnetic device using the same

• US 20020036876A1
• Filed: 09/04/2001
• Published: 03/28/2002
• Est. Priority Date: 09/06/2000
• Status: Abandoned Application

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Sugita, Yasunari, Odagawa, Akihiro, Kawawake, Yasuhiro, Sakakima, Hiroshi, Yoshida, Akihisa
• Application Number:
  US09/946,643
• Publication Number:
  US 20020036876A1
• Time in Patent Office: Days
• 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: B82Y 40/00 Manufacture or treatment of nanostructures
• 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 5/3909 Arrangements using a magnetic tunnel junction
• CPC Class Codes: G11B 5/398 Specially shaped layers
• CPC Class Codes: H01F 10/3254 the spacer being semiconducting or insulating, e.g. for spin tunnel junction [STJ]
• CPC Class Codes: H01F 41/302 for applying spin-exchange-coupled multilayers, e.g. nanostructured superlattices spin-exchange-coupled multilayers H01F10/32
• CPC Class Codes: Y10T 29/49044 Plural magnetic deposition layers

Abstract

The invention increases the electric resistance of CPP-GMR elements to a practical range. Moreover, the invention presents a CPP-GMR element and a TMR element that can be applied to track widths that are made narrower due to higher densities of the magnetic recording. The area S₁ of a non-magnetic layer 7 is 1 μm or less, and at least one layer selected from a first magnetic layer 6, a second magnetic layer 8 and the non-magnetic layer 7 includes a first region 30 through which current flows and a second region 20 made of an oxide, a nitride or an oxynitride of the film constituting that first region. The area S₂ of the first region is smaller than the area of the non-magnetic layer. At least one of the layers of the element is oxidized, nitrided or oxynitrided from a lateral side.

Claims

1. A magnetoresistive element comprising:

a non-magnetic layer; and

a first and a second magnetic layer sandwiching the non-magnetic layer;

wherein a current for sensing a change in magnetic resistance based on a change in the relative angle between a magnetization direction of the first magnetic layer and a magnetization direction of the second magnetic layer flows perpendicular with respect to the layers;

wherein the non-magnetic layer has an area of not more than 1 μ

m²;

wherein at least one layer selected from the first and second magnetic layers and the non-magnetic layer includes a first region through which said current flows and a second region made of an oxide, a nitride or an oxynitride of the material of which the first region is made; and

wherein the first region is smaller than an area of the non-magnetic layer.

2. The magnetoresistive element according to claim 1, wherein the second region accounts for at least 10% of the non-magnetic layer.

3. The magnetoresistive element according to claim 1, wherein the area of the non-magnetic layer is not larger than 0.1 μ

m².

4. The magnetoresistive element according to claim 1, wherein at least the non-magnetic layer has the first region and the second region.

5. The magnetoresistive element according to claim 4, wherein the first region of the non-magnetic layer has at least one main component selected from the group consisting of Cu, Ag, Au, Ir, Ru, Rh and Cr.

6. The magnetoresistive element according to claim 4, wherein the non-magnetic layer is at least 0.8 nm and at most 10 nm thick.

7. The magnetoresistive element according to claim 1, wherein at least the first magnetic layer and the second magnetic layer have the first region and the second region.

8. The magnetoresistive element according to claim 7, wherein the non-magnetic layer is an insulating layer.

9. The magnetoresistive element according to claim 7, wherein the non-magnetic layer has at least one main component selected from aluminum oxide, aluminum nitride, aluminum oxynitride, magnesium oxide and strontium titanate.

10. The magnetoresistive element according to claim 7, wherein the non-magnetic layer is at least 0.4 nm and at most 2 nm thick.

11. The magnetoresistive element according to claim 1, further comprising a magnetization rotation control layer magnetically coupling with at least one layer selected from the first magnetic layer and the second magnetic layer.

12. The magnetoresistive element according to claim 11, wherein the magnetization rotation control layer is an antiferromagnetic layer.

14. The method for manufacturing a magnetoresistive element according to claim 13, wherein the oxidizing, nitriding or oxynitriding is performed by heating said layer to at least 100°

C., and introducing a gas including at least one selected from oxygen atoms and nitrogen atoms into the lateral side of said layer.

15. The method for manufacturing a magnetoresistive element according to claim 13, wherein the oxidizing, nitriding or oxynitriding is performed by implanting the lateral side of said layer with at least one selected from oxygen ions and nitrogen ions.

16. The method for manufacturing a magnetoresistive element according to claim 13, further comprising

forming an electrode for conducting the current;

and

forming a protective film covering at least a portion of the electrode;

wherein a portion of said layer is oxidized, nitrided or oxynitrided after forming the protective layer.

17. The method for manufacturing a magnetoresistive element according to claim 13, wherein a layer having at least one main component selected from the group consisting of Cu, Ag, Au, Ir, Ru, Rh and Cr is formed as the non-magnetic layer.

18. The method for manufacturing a magnetoresistive element according to claim 17, wherein at least a lateral side of the non-magnetic layer is oxidized, nitrided or oxynitrided.

20. The method for manufacturing a magnetoresistive element according to claim 19, wherein at least a lateral side of the first magnetic layer or the second magnetic layer is oxidized, nitrided or oxynitrided.

21. A magnetoresistive head comprising:

a magnetoresistive element according to claim 1;

and

a pair of magnetic shields arranged so as to sandwich the magnetoresistive element.

22. The magnetoresistive head according to claim 21, wherein a region for detecting magnetism from a magnetic recording medium is not more than 0.1 μ

m wide.

23. A magnetic recording apparatus comprising:

a magnetoresistive head according to claim 21; and

a magnetic recording medium for recording or reproducing information with the magnetic head.

13. A method for manufacturing a magnetoresistive element comprising a non-magnetic layer, and a first and a second magnetic layer sandwiching the non-magnetic layer, wherein a current for sensing a change in magnetic resistance based on a change in the relative angle between a magnetization direction of the first magnetic layer and a magnetization direction of the second magnetic layer flows perpendicular with respect to the layers;

the method comprising;

forming the first magnetic layer, the non-magnetic layer, and the second magnetic layer such that the non-magnetic layer has an area of not more than 1 μ

m²; and

oxidizing, nitriding or oxynitriding a portion of at least one layer selected from the first magnetic layer, the non-magnetic layer, and the second magnetic layer from a lateral side.

19. The method for manufacturing a magnetoresistive element according to any of claims 13 to 16, wherein an insulating layer is formed as the non-magnetic layer.