Method of manufacturing spin torque oscillator

• US 9,721,594 B2
• Filed: 11/21/2014
• Issued: 08/01/2017
• Est. Priority Date: 12/03/2010
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Shirotori, Satoshi, Koui, Katsuhiko, Takeo, Akihiko, Yamada, Kenichiro
• Primary Examiner(s): Kim, Paul D
• Application Number:
  US14/550,729
• Publication Number:
  US 20150074986A1
• Time in Patent Office: 984 Days
• Field of Search: 295921, 29593, 29594, 29595, 296091
• CPC Class Codes: B82Y 40/00 Manufacture or treatment of nanostructures
• CPC Class Codes: G11B 2005/0024 Microwave assisted recording
• CPC Class Codes: G11B 5/1278 specially adapted for magnetisations perpendicular to the surface of the record carrier
• CPC Class Codes: G11B 5/314 where the layers are extra layers normally not provided in the transducing structure, e.g. optical layers G11B5/3196 takes precedence
• 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: H01F 10/325 the spacer being noble metal
• CPC Class Codes: H01F 10/3286 Spin-exchange coupled multilayers having at least one layer with perpendicular magnetic anisotropy
• CPC Class Codes: H01F 10/329 Spin-exchange coupled multilayers wherein the magnetisation of the free layer is switched by a spin-polarised current, e.g. spin torque effect
• 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: H01F 41/308 lift-off processes, e.g. ion milling, for trimming or patterning
• CPC Class Codes: H10N 50/10 Magnetoresistive devices
• CPC Class Codes: Y10T 29/4902 Electromagnet, transformer or inductor
• CPC Class Codes: Y10T 29/49032 Fabricating head structure or component thereof
• CPC Class Codes: Y10T 428/1186 with head pole component

Abstract

According to one embodiment, there is provided a spin torque oscillator including an oscillation layer formed of a magnetic material, a spin injection layer formed of a magnetic material and configured to inject a spin into the oscillation layer, and a current confinement layer including an insulating portion formed of an oxide or a nitride and a conductive portion formed of a nonmagnetic metal and penetrating the insulating portion in a direction of stacking. The conductive portion of the current confinement layer is positioned near a central portion of a plane of a device region including the oscillation layer and the spin injection layer.

Claims

1. A method of manufacturing a spin torque oscillator, the method comprising:

forming a metal layer to be converted into a current confinement layer on a stack including an oscillation layer comprising a magnetic material and a spin injection layer comprising a magnetic material;

forming, on the metal layer, a mask layer with a tapered surface at an end thereof; and

oxidizing or nitriding an end of the metal layer located under the mask layer formed to include the tapered surface at the end thereof, to form the current confinement layer comprising an insulating portion comprising an oxide or a nitride and a conductive portion comprising a nonmagnetic metal and penetrating the insulating portion in a direction of stacking, wherein

the conductive portion of the current confinement layer has a rectangular planar shape, and

a device region including the oscillation layer and the spin injection layer has a rectangular planar shape in a size of 50 nm×

50 nm or less, and

the conductive portion of the current confinement layer is positioned near a central portion of a plane of the device region including the oscillation layer and the spin injection layer, and

the insulating portion is between each of three sides of the conductive portion and a corresponding one of four sides of the device region, and

a fourth side of the conductive portion is at one of the four sides of the device region without the insulating portion being between the fourth side of the conductive region and the one of the four sides of the device region.

2. The method of claim 1, wherein the current confinement layer is 20% or more and 90% or less of the oscillation layer in width.

3. The method of claim 1, wherein the current confinement layer is positioned in a topmost surface.

4. The method of claim 1, wherein the current confinement layer comprises titanium.