Magnetoresistive element and method of manufacturing the same

• US 8,184,408 B2
• Filed: 01/30/2009
• Issued: 05/22/2012
• Est. Priority Date: 01/30/2008
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Fukuzawa, Hideaki, Yuasa, Hiromi, Fuji, Yoshihiko, Murakami, Shuichi
• Primary Examiner(s): MAI, SON LUU
• Application Number:
  US12/320,668
• Publication Number:
  US 20090190262A1
• Time in Patent Office: 1,208 Days
• Field of Search: 360/324.11
• US Class Current: 360/324.11
• 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 5/3906 Details related to the use of magnetic thin film layers or to their effects
• CPC Class Codes: G11C 11/161 details concerning the memory cell structure, e.g. the layers of the ferromagnetic memory cell
• CPC Class Codes: H10B 61/22 of the field-effect transistor [FET] type
• CPC Class Codes: H10N 50/01 Manufacture or treatment
• CPC Class Codes: H10N 50/10 Magnetoresistive devices
• CPC Class Codes: H10N 50/85 Magnetic active materials

Abstract

A magnetoresistive element includes a magnetoresistive film including a magnetization pinned layer, a magnetization free layer, an intermediate layer arranged between the magnetization pinned layer and the magnetization free layer, a cap layer arranged on the magnetization pinned layer or on the magnetization free layer, and a functional layer formed of an oxygen- or nitrogen-containing material and arranged in the magnetization pinned layer, or in the magnetization free layer, and a pair of electrodes which pass a current perpendicularly to a plane of the magnetoresistive film, in which a crystalline orientation plane of the functional layer is different from a crystalline orientation plane of its upper or lower adjacent layer.

Claims

1. A magnetoresistive element comprising:

a magnetoresistive film comprising a magnetization pinned layer a magnetization direction of which is substantially pinned in one direction, a magnetization free layer a magnetization direction of which is varied depending on an external magnetic field, an intermediate layer arranged between the magnetization pinned layer and the magnetization free layer, a cap layer arranged on the magnetization pinned layer or on the magnetization free layer, and a functional layer formed of an oxygen- or nitrogen-containing material and arranged in the magnetization pinned layer, in the magnetization free layer, in an interface between the magnetization pinned layer and the intermediate layer, in an interface between the intermediate layer and the magnetization free layer, or in an interface between the magnetization pinned layer or the magnetization free layer and the cap layer; and

a pair of electrodes which pass a current perpendicularly to a plane of the magnetoresistive film,

wherein a crystalline orientation plane of the functional layer is different from a crystalline orientation plane of its upper or lower adjacent layer.

2. The magnetoresistive element according to claim 1, wherein reciprocal lattice spots of the crystalline orientation plane of the functional layer and reciprocal lattice spots of the crystalline orientation plane of its upper or lower adjacent layer are inclined to each other at 10 to 90 degrees.

4. The magnetoresistive element according to claim 1, wherein the functional layer has a crystalline orientation dispersion angle of 5 degrees or less.

5. The magnetoresistive element according to claim 1, wherein the magnetization pinned layer or the magnetization free layer has a crystalline orientation dispersion angle of 5 degrees or less.

6. The magnetoresistive element according to claim 1, wherein the functional layer has a thickness from 0.3 nm to 5 nm.

7. The magnetoresistive element according to claim 1, wherein the functional layer comprises a material selected from the group consisting of Fe, Co, Ni, Mn and Cr.

8. The magnetoresistive element according to claim 1, wherein the functional layer comprises a material selected from the group consisting of Al, Si, Mg, Zr, Hf, Nb, W, Ti and Pd.

9. The magnetoresistive element according to claim 1, wherein the intermediate layer is a metal layer comprising an element selected from the group consisting of Au, Ag and Cu.

10. The magnetoresistive element according to claim 1, wherein the intermediate layer comprises an insulating layer containing nitrogen or oxygen and a current path penetrating the insulating layer.

11. The magnetoresistive element according to claim 9, wherein the current path comprises an element selected from the group consisting of Au, Ag, Cu, Fe, Co and Ni.

14. A magnetic head gimbal assembly comprising the magnetoresistive element of claim 1.

15. A magnetic recording apparatus comprising the magnetic head gimbal assembly of claim 14.

3. A magnetoresistive element comprising:

a magnetoresistive film comprising a magnetization pinned layer a magnetization direction of which is substantially pinned in one direction, a magnetization free layer a magnetization direction of which is varied depending on an external magnetic field, an intermediate layer arranged between the magnetization pinned layer and the magnetization free layer, a cap layer arranged on the magnetization pinned layer or on the magnetization free layer, and a functional layer arranged in the magnetization pinned layer, in the magnetization free layer, in an interface between the magnetization pinned layer and the intermediate layer, in an interface between the intermediate layer and the magnetization free layer, or in an interface between the magnetization pinned layer or the magnetization free layer and the cap layer; and

a pair of electrodes which pass a current perpendicularly to a plane of the magnetoresistive film,

wherein reciprocal lattice spots of the crystalline orientation plane of the functional layer and reciprocal lattice spots of the crystalline orientation plane of its upper or lower adjacent layer are inclined to each other at 10 to 90 degrees.

12. A magnetoresistive element comprising:

a magnetoresistive film comprising a first magnetization free layer a magnetization direction of which is varied depending on an external magnetic field, a second magnetization free layer a magnetization direction of which is varied depending on an external magnetic field, an intermediate layer arranged between the first magnetization free layer and the second magnetization free layer, and a functional layer arranged in the first magnetization free layer, in the second magnetization free layer, in an interface between the first magnetization free layer and the intermediate layer, in an interface between the intermediate layer and the second magnetization free layer, or in an interface of the second magnetization free layer opposite to the interface that is in contact with the intermediate layer; and

a pair of electrodes which pass a current perpendicularly to a plane of the magnetoresistive film,

wherein a crystalline orientation plane of the functional layer is different from a crystalline orientation plane of its upper or lower adjacent layer.

13. The magnetoresistive element according to claim 12, wherein reciprocal lattice spots of the crystalline orientation plane of the functional layer and reciprocal lattice spots of the crystalline orientation plane of its upper or lower adjacent layer are inclined to each other at 10 to 90 degrees.

16. A method of manufacturing a magnetoresistive element comprising a magnetoresistive film comprising a functional layer formed of an oxygen- or nitrogen-containing material and arranged in a magnetization pinned layer, in a magnetization free layer, in an interface between the magnetization pinned layer and an intermediate layer, in an interface between the intermediate layer and the magnetization free layer, or in an interface between the magnetization pinned layer or the magnetization free layer, the method comprising:

depositing a metal layer and exposing the metal layer to either oxygen or nitrogen gas to form the functional layer; and

repeating the depositing step two or more times.

17. The method according to claim 16, wherein the metal layer comprises a material selected from the group consisting of Fe, Co, Ni, Mn and Cr.

18. The method according to claim 16, wherein the functional layer is a layer containing nitrogen, and a thickness of the functional layer in T nanometers and a number of times N, by which the modules are repeated, satisfy the following formula:

N≧

(T/0.5)×

x,

where x is a constant of 1 to 2, and T≧

1.

19. The method according to claim 16, wherein a thickness of the metal layer deposited in one module is 1 nm or less.

20. The method according to claim 16, wherein the functional layer is a layer containing oxygen, and a thickness of the functional layer in T nanometers and a number of times N, by which the modules are repeated, satisfy the following formula:

N≧

(T/1)×

x,

where x is a constant of 1 to 2, and T≧

1.