Perpendicular magnetic tunnel junction retention and endurance improvement

Patent metadata

Field	Value
Publication number	US-10651370-B2
Application number	US-201715859224-A
Country	US
Kind code	B2
Filing date	Dec 29, 2017
Priority date	Dec 29, 2017
Publication date	May 12, 2020
Grant date	May 12, 2020

Abstract

A magnetic data recording element for magnetic random access memory data recording. The magnetic data recording element includes a magnetic tunnel junction element that includes a magnetic reference layer, a magnetic free layer and a non-magnetic barrier layer located between the non-magnetic reference layer and the magnetic free layer. The magnetic free layer includes a layer of Hf that causes the magnetic free layer to have an increased perpendicular magnetic anisotropy. This increased perpendicular magnetic anisotropy improves data retention and increases thermal stability, by preventing the magnetization of the magnetic free layer from inadvertently losing its magnetic orientation.

First claim

What is claimed is:

1. A magnetic random access memory element comprising:
a magnetic reference layer;
a magnetic free layer; and
a non-magnetic barrier layer, located between the magnetic reference layer and the magnetic free layer;
the magnetic free layer comprising a magnetic material, a layer of Hf, and a layer of W, wherein the layer of layer of Hf and the layer of W contact one another, the layer of Hf and the layer of W both contact the magnetic material; wherein
the layer of Hf and the layer of W each have a thickness of 1-6 Angstroms.

2. The magnetic random access memory element as in claim 1 , further comprising a layer of Mg—O formed over the magnetic free layer at a location opposite the non-magnetic barrier layer.

3. The magnetic random access memory element as in claim 1 further comprising a layer of Mg—O.

4. The magnetic random access memory element as in claim 1 wherein the magnetic free layer further comprises a layer of Mg—O and wherein the layer of Mg—O has a thickness of 2-6 Angstroms.

5. A magnetic random access memory element, comprising:
a magnetic reference layer;
a magnetic free layer; and
a non-magnetic barrier layer disposed between the magnetic reference layer and the magnetic free layer;
wherein the magnetic free layer comprises:
a first magnetic layer;
a second magnetic layer;
a spacer layer located between the first magnetic layer and the second magnetic layer, the spacer layer comprising a layer of Hf in contact with the first magnetic layer and a layer of W in contact with the second magnetic layer; wherein each of the layer of Hf and the layer of W have a thickness of 1-6 Angstroms.

6. The magnetic random access memory element as in claim 5 , wherein the layer of Hf and the layer of W contact one another.

7. The magnetic random access memory element as in claim 5 , wherein the spacer layer includes a layer of Mg—O.

8. The magnetic random access memory element as in claim 5 , wherein the spacer layer is sufficiently thin to maintain exchange coupling between the first and second magnetic layers.

9. The magnetic random access memory element as in claim 5 , wherein the layer of W is located between the layer of layer of Hf and the non-magnetic barrier layer.

10. The magnetic random access memory element as in claim 5 , wherein the spacer layer has a total thickness not greater than 6 nm.

11. The magnetic random access memory element as in claim 5 , further comprising a cap layer formed over the magnetic free layer, the cap layer including a layer of Mg—O and a layer of Hf.

12. A magnetic random access memory system, comprising:
a memory element that includes a magnetic reference layer, a magnetic free layer and a non-magnetic barrier layer located between the magnetic reference layer and the magnetic free layer; and
circuitry electrically connected with the memory element, the circuitry being functional to supply a current to the magnetic element to write a data bit to the magnetic memory element and to measure an electrical resistance of the memory element to read a data bit from the memory element;
wherein the magnetic free layer further comprises:
first and second magnetic layers and a spacer layer located between the first and second magnetic layers, the spacer layer comprising a layer of Hf in contact with the first magnetic layer and a layer of W in contact with the layer of Hf and also in contact with the second magnetic layer; wherein each of the layer of Hf and the layer of W have a thickness of 1-6 Angstroms.

13. The magnetic random access memory system as in claim 12 , further comprising a cap layer including a layer of Hf located over the magnetic free layer.

14. The magnetic random access memory system as in claim 12 further comprising a cap layer formed over the magnetic free layer, the cap layer comprising a layer of Hf and a layer of W.

Assignees

• Spin Memory Inc

Inventors

• Pinarbasi Mustafa
• KARDASZ Bartlomiej Adam
• Vasquez Jorge
• Boone Thomas D

Classifications

• 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

• H01F10/3286 Primary

  Spin-exchange coupled multilayers having at least one layer with perpendicular magnetic anisotropy · CPC title

• H01F10/3272

  by use of anti-parallel coupled [APC] ferromagnetic layers, e.g. artificial ferrimagnets [AFI], artificial [AAF] or synthetic [SAF] anti-ferromagnets · CPC title

• H01F10/3254

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

• G11C11/1675

  Writing or programming circuits or methods · CPC title