METHOD OF MANUFACTURING MAGNETORESISTIVE ELEMENT

• US 20120050920A1
• Filed: 07/19/2011
• Published: 03/01/2012
• Est. Priority Date: 09/01/2010
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Takeo, Akihiko, Fuji, Yoshihiko, Yuasa, Hiromi, Hara, Michiko, Murakami, Shuichi, Fukuzawa, Hideaki
• Granted Patent: US 8,685,491 B2
• Time in Patent Office: Days
• US Class Current: 360/246.1
• 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: G01R 33/093 using multilayer structures, e.g. giant magnetoresistance sensors thin magnetic films H01F10/00
• CPC Class Codes: G01R 33/098 comprising tunnel junctions, e.g. tunnel magnetoresistance sensors
• CPC Class Codes: G11B 5/3163 Fabrication methods or processes specially adapted for a particular head structure, e.g. using base layers for electroplating, using functional layers for masking, using energy or particle beams for shaping the structure or modifying the properties of the basic layers
• 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 5/3983 with current confined paths in the spacer layer
• CPC Class Codes: H01F 10/3259 Spin-exchange-coupled multilayers comprising at least a nanooxide layer [NOL], e.g. with a NOL spacer
• CPC Class Codes: H01F 10/3272 by use of anti-parallel coupled [APC] ferromagnetic layers, e.g. artificial ferrimagnets [AFI], artificial [AAF] or synthetic [SAF] anti-ferromagnets
• CPC Class Codes: H01F 10/3295 Spin-exchange coupled multilayers wherein the magnetic pinned or free layers are laminated without anti-parallel coupling within the pinned and free layers
• CPC Class Codes: H01F 41/303 with exchange coupling adjustment of magnetic film pairs, e.g. interface modifications by reduction, oxidation
• CPC Class Codes: H01F 41/325 applying a noble metal capping on a spin-exchange-coupled multilayer, e.g. spin filter deposition
• CPC Class Codes: H10N 50/01 Manufacture or treatment
• CPC Class Codes: Y10T 428/1129 Super lattice [e.g., giant magneto resistance [GMR] or colossal magneto resistance [CMR], etc.]

Abstract

According to one embodiment, a method of manufacturing a magnetoresistive element includes a layered structure and a pair of electrodes, the layered structure including a cap layer, a magnetization pinned layer, a magnetization free layer, a spacer layer and a functional layer provided in the magnetization pinned layer, between the magnetization pinned layer and the spacer layer, between the spacer layer and the magnetization free layer, in the magnetization free layer, or between the magnetization free layer and the cap layer and including an oxide, the method including forming a film including a base material of the functional layer, performing an oxidation treatment on the film using a gas containing oxygen in a form of at least one selected from the group consisting of molecule, ion, plasma and radical, and performing a reduction treatment using a reducing gas on the film after the oxidation treatment.

Claims

1. A method of manufacturing a magnetoresistive element comprising a layered structure and a pair of electrodes allowing an electric current to flow through the layered structure in a thickness direction, the layered structure comprising:

a cap layer;

a magnetization pinned layer;

a magnetization free layer provided between the cap layer and the magnetization pinned layer;

a spacer layer provided between the magnetization pinned layer and the magnetization free layer; and

a functional layer provided in the magnetization pinned layer, between the magnetization pinned layer and the spacer layer, between the spacer layer and the magnetization free layer, in the magnetization free layer, or between the magnetization free layer and the cap layer and comprising an oxide containing at least one element selected from the group consisting of Zn, In, Sn, and Cd and at least one element selected from the group consisting of Fe, Co, and Ni;

the method comprising;

forming a film comprising a base material of the functional layer;

performing an oxidation treatment on the film using a gas containing oxygen in a form of at least one selected from the group consisting of molecule, ion, plasma and radical; and

performing a reduction treatment using a reducing gas on the film after the oxidation treatment.

2. The method of manufacturing a magnetoresistive element of claim 1, wherein the reducing gas comprises at least one selected from the group consisting of argon, helium, neon, krypton and xenon in a form of ion, plasma or radical and/or at least one selected from the group consisting of hydrogen and nitrogen in a form of molecule, ion, plasma or radical.

3. The method of manufacturing a magnetoresistive element of claim 1, wherein the reducing gas comprises at least one selected from the group consisting of argon, helium, neon, krypton, xenon, hydrogen and nitrogen in a form of ion or plasma.

4. The method of manufacturing a magnetoresistive element of claim 1, wherein the reducing gas comprises argon in a form of ion or plasma.

5. The method of manufacturing a magnetoresistive element of claim 1, wherein crystallinity of the film is improved by the reduction treatment.

6. The method of manufacturing a magnetoresistive element of claim 1, wherein the reduction treatment is performed while heating the film.

7. The method of manufacturing a magnetoresistive element of claim 1, further comprising performing, on the film after the reduction treatment, at least one moisture elimination treatment selected from the group consisting of irradiation with an argon ion, irradiation with argon plasma, and heating.

8. The method of manufacturing a magnetoresistive element of claim 7, wherein the reduction treatment and the moisture elimination treatment are repeated a plurality of times.

9. The method of manufacturing a magnetoresistive element of claim 7, wherein the film formation, the oxidation treatment, the reduction treatment, and the moisture elimination treatment are repeated a plurality of times.

10. The method of manufacturing a magnetoresistive element of claim 1, wherein the film formation, the oxidation treatment, and the reduction treatment are repeated a plurality of times.

11. The method of manufacturing a magnetoresistive element of claim 1, wherein the film formation and the oxidation treatment are repeated a plurality of times.

12. The method of manufacturing a magnetoresistive element of claim 1, wherein the oxidation treatment comprises converting the base material of the functional layer into an oxide by supplying the film with gaseous oxygen in an atmosphere obtained by ionization or plasma formation of a gas containing at least one selected from the group consisting of argon, xenon, helium, neon, and krypton.

13. The method of manufacturing a magnetoresistive element of claim 2, wherein the ion or plasma of argon, helium, neon, krypton, or xenon is produced in the reduction treatment using a high-frequency bias of 20 to 100 W or less.

14. A magnetoresistive element manufactured by the method of claim 1.

15. A magnetic head assembly comprising:

a suspension,

the magnetoresistive element of claim 14 mounted at one end of the suspension, and

an actuator arm connected to the other end of the suspension.

16. A magnetic recording apparatus comprising:

the magnetic head assembly of claim 15 and

a magnetic recording medium on which information is to be recorded, the information on the magnetic recording medium being read by the magnetoresistive element mounted to the magnetic head assembly.

17. The magnetic recording apparatus of claim 16, wherein the magnetoresistive elements are disposed in matrix.