Spin torque oscillator having multiple fixed ferromagnetic layers or multiple free ferromagnetic layers

Patent metadata

Field	Value
Publication number	US-9729106-B2
Application number	US-201514943209-A
Country	US
Kind code	B2
Filing date	Nov 17, 2015
Priority date	Dec 20, 2010
Publication date	Aug 8, 2017
Grant date	Aug 8, 2017

Abstract

A spin torque oscillator and a method of making same. The spin torque oscillator is configured to generate microwave electrical oscillations without the use of a magnetic field external thereto, the spin torque oscillator having one of a plurality of input nanopillars and a nanopillar having a plurality of free FM layers.

First claim

What is claimed is:

1. A spin torque oscillator comprising:
a free ferromagnetic (FM) layer;
a non-magnetic layer on the free FM layer; and
nanopillars, including input nanopillars and an output nanopillar, on the non-magnetic layer;
wherein the nanopillars each include a fixed magnetic layer.

2. The oscillator of claim 1 comprising at least three input nanopillars.

3. The oscillator of claim 1 , wherein the input nanopillars surround the output nanopillar.

4. The oscillator of claim 1 , wherein two input nanopillars are to direct current of a first polarity and a third input nanopillar is to direct current of a second polarity opposite the first polarity.

5. The oscillator of claim 1 , wherein:
the input nanopillars include at least three nanopillars;
two input nanopillars are adapted to direct current of a first polarity; and
a third input nanopillar is adapted to direct current of a second polarity that is opposite the first polarity.

6. The oscillator of claim 1 , wherein each of the nanopillars includes an anti-ferromagnetic (AFM) pinning layer.

7. The oscillator of claim 6 comprising:
a ground electrode, the free FM layer being on the ground electrode; and
an electrode on each of the respective pinning layers.

8. The oscillator of claim 7 , wherein the ground electrode and each electrode on the respective pinning layers each includes a non-magnetic metal.

9. The oscillator of claim 1 , wherein the free FM layer has an elliptical cross-section.

10. The oscillator of claim 1 , wherein each of the nanopillars has an elliptical cross-section.

11. The oscillator of claim 1 , wherein the non-magnetic layer includes a tunnel junction.

12. The oscillator of claim 1 , wherein the non-magnetic layer includes copper.

13. The oscillator of claim 1 , wherein the non-magnetic layer includes a dielectric material.

14. The oscillator of claim 1 , wherein the nanopillars are insulated from one another, the non-magnetic layer is monolithic and extends below each of the nanopillars, and the free FM layer is monolithic and extends below each of the nanopillars.

15. The oscillator of claim 1 including no output nanopillar other than the output nanopillar.

16. The oscillator of claim 1 comprising electrodes and the nanopillars are between the non-magnetic layer and electrodes.

17. The oscillator of claim 1 , wherein the output pillar is configured to output oscillating current.

18. A system comprising:
a device layer included in a substrate;
inter-layer dielectric layers on the device layer;
metal interconnects between the inter-layer dielectric layers; and
a spin torque oscillator between two of the metal interconnects such that the two metal interconnects correspond to electrodes of the oscillator;
wherein the oscillator comprises:
a free ferromagnetic (FM) layer;
a non-magnetic layer on the free FM layer; and
nanopillars, including input nanopillars and an output nanopillar, on the non-magnetic layer;
wherein the nanopillars each include a fixed magnetic layer.

19. The system of claim 18 , wherein two input nanopillars are to direct current of a first polarity and a third input nanopillar is to direct current of a second polarity opposite the first polarity.

20. The system of claim 18 , wherein each of the nanopillars includes an anti-ferromagnetic (AFM) pinning layer on the respective fixed magnetic layer.

21. The system of claim 18 , wherein the non-magnetic layer includes a dielectric material.

22. The system of claim 18 , wherein the nanopillars are insulated from one another, the non-magnetic layer is monolithic and extends below each of the nanopillars, and the free FM layer is monolithic and extends below each of the nanopillars.

Assignees

• Intel Corp

Inventors

• Nikonov Dmitri E
• Bourianoff George I

Classifications

• H01F41/308

  lift-off processes, e.g. ion milling, for trimming or patterning · CPC title

• H01F10/329

  Spin-exchange coupled multilayers wherein the magnetisation of the free layer is switched by a spin-polarised current, e.g. spin torque effect · CPC title

• H01F10/3254 Primary

  the spacer being semiconducting or insulating, e.g. for spin tunnel junction [STJ] · CPC title

• H01S1/02

  solid · CPC title

• H03L7/26

  using energy levels of molecules, atoms, or subatomic particles as a frequency reference · CPC title