Method and system for providing a dual magnetic junction having mitigated flowering field effects

Patent metadata

Field	Value
Publication number	US-2018190898-A1
Application number	US-201615396296-A
Country	US
Kind code	A1
Filing date	Dec 30, 2016
Priority date	Dec 30, 2016
Publication date	Jul 5, 2018
Grant date	—

Abstract

A magnetic junction and method for providing the magnetic junction are described. The magnetic junction includes a free layer, first and second reference layers, and first and second nonmagnetic spacer layers. The free layer is switchable between stable magnetic states using a current passed through the magnetic junction. The first and second nonmagnetic spacer layers are between the free layer and first and second reference layers. The first and second reference layers have first and second reference layer magnetic lengths. The free layer has a free layer magnetic length less than the first and second reference layer magnetic lengths. The free layer magnetic length has a first end and a second end opposite to the first end. The free layer and the reference layers are oriented such that the first and second reference layer magnetic lengths extend past the first and second ends of the free layer.

First claim

1 . A magnetic junction usable in a magnetic device comprising:
a first reference layer having a first reference layer magnetic length; a first nonmagnetic spacer layer; a free layer, the free layer being switchable between a plurality of stable magnetic states using a write current passed through the magnetic junction, the first nonmagnetic spacer layer being between the first reference layer and the free layer, the free layer having a free layer magnetic length less than the first reference layer magnetic length, the free layer magnetic length having a first end and a second end opposite to the first end, the free layer and the first reference layer being oriented such that the first reference layer magnetic length extends past the first end and past the second end of the free layer; a second nonmagnetic spacer layer, the free layer being between the first nonmagnetic spacer layer and the second nonmagnetic spacer layer; a polarization enhancement layer (PEL), the second nonmagnetic spacer being between the PEL and the free layer; a texture blocking layer, the PEL being between the second nonmagnetic spacer layer and the texture blocking layer; and a second reference layer having a second reference layer magnetic length greater than the free layer magnetic length, the second nonmagnetic spacer layer being between the free layer and the second reference layer, the texture blocking layer being between the PEL and the second reference layer, the free layer and the second reference layer being oriented such that the second reference layer magnetic length extends past the first end and past the second end of the free layer.

2 . The magnetic junction of claim 1 wherein the free layer has a free layer perpendicular magnetic anisotropy energy greater than a free layer out-of-plane demagnetization energy.

3 . The magnetic junction of claim 1 wherein at least one of the first reference layer and the second reference layer is a synthetic antiferromagnet including a first magnetic layer, a second magnetic layer and a nonmagnetic coupling layer between the first magnetic layer and the second magnetic layer.

4 . The magnetic junction of claim 1 wherein at least one of the first reference layer and the second reference layer is a shared reference layer.

5 . The magnetic junction of claim 1 wherein the first reference layer magnetic length extends past the first end of the free layer by at least five nanometers and extends past the second end of the free layer by at least five nanometers and wherein the second reference layer magnetic length extends past the first end of the free layer by at least five nanometers and extends past the second end of the free layer by at least five nanometers.

6 . The magnetic junction of claim 5 wherein the first reference layer magnetic length extends past the first end of the free layer by not more than ten nanometers and extends past the second end of the free layer by not more than ten nanometers and wherein the second reference layer magnetic length extends past the first end of the free layer by not more than ten nanometers and extends past the second end of the free layer by not more than ten nanometers.

7 . The magnetic junction of claim 5 wherein the layer magnetic length is substantially centered with respect to at least one of the first reference layer magnetic length and the second reference layer magnetic length.

8 . The magnetic junction of claim 1 wherein the free layer magnetic length is substantially the same as a free layer physical length.

9 . The magnetic junction of claim 1 wherein the free layer magnetic length is less than the free layer physical length and wherein the free layer includes a magnetic material and at least one material having a greater oxygen affinity than the magnetic material.

10 . A magnetic memory comprising:
a plurality of magnetic storage cells, each of the plurality of magnetic storage cells including at least one magnetic junction having a first reference layer, a first nonmagnetic spacer layer, a free layer, a second nonmagnetic spacer layer, a polarization enhancement layer (PEL), a texture blocking layer and a second reference layer, the first reference layer having a first reference layer magnetic length, the free layer being switchable between a plurality of stable magnetic states using a write current passed through the magnetic junction, the first nonmagnetic spacer layer residing between the first reference layer and the free layer, the free layer having a free layer magnetic length less than the first reference layer magnetic length, the free layer magnetic length having a first end and a second end opposite to the first end, the free layer and the first reference layer being oriented such that the first reference layer magnetic length extends past the first end and past the second end of the free layer, the free layer being between the first nonmagnetic spacer layer and the second nonmagnetic spacer layer, the second nonmagnetic spacer being between the PEL and the free layer, the PEL being between the second nonmagnetic spacer layer and the texture blocking layer, the second reference layer having a second pinned magnetic layer length greater than the free layer magnetic length, the second nonmagnetic spacer layer being between the free layer and the second reference layer, the free layer and the second reference layer being oriented such that the second reference layer magnetic length extends past the first end and past the second end of the free layer; and a plurality of bit lines coupled with the plurality of magnetic storage cells.

11 . A method for providing magnetic junction usable in a magnetic device, the method comprising:
providing a magnetoresistive stack including at least a first fixed magnetic layer, a first nonmagnetic layer, a free magnetic layer, a second nonmagnetic layer, a polarization layer, a blocking layer and a second fixed magnetic layer, the first fixed magnetic layer corresponding to a first reference layer having a first reference layer magnetic length, the first nonmagnetic layer corresponding to a first nonmagnetic spacer layer, the free magnetic layer corresponding to a free layer switchable between a plurality of stable magnetic states using a write current passed through the magnetic junction, the second nonmagnetic layer corresponding to a second nonmagnetic spacer layer, the polarization layer corresponding to a polarization enhancement layer, the blocking layer corresponding to a texture blocking layer, the second fixed magnetic layer corresponding to at least a portion of a second reference layer, the first nonmagnetic spacer layer residing between the first reference layer and the free layer, the free layer being between the first nonmagnetic spacer layer and the second nonmagnetic spacer layer, the second nonmagnetic spacer layer being between the free layer and the second reference layer, the PEL being between the second nonmagnetic spacer layer and the texture blocking layer, the texture blocking layer being between the PEL and the second reference layer; defining a free layer magnetic length for the free layer, the free layer magnetic length being less than a first reference layer magnetic length of the first reference layer and being less than a second reference layer magnetic length of the second reference layer, the free layer magnetic length having a first end and a second end opposite to the first end, the free layer and the first reference layer being oriented such that the first reference layer magnetic length extends past the first end and past the second end of the free layer, the free layer and the second reference layer being oriented such that the second reference lay

Assignees

• Samsung Electronics Co Ltd

Inventors

• Wang Shuxia
• Apalkov Dmytro
• Nikitin Vladimir

Classifications

• G11C11/161

  details concerning the memory cell structure, e.g. the layers of the ferromagnetic memory cell · CPC title

• H01L43/10

  Electricity · mapped topic

• H01L43/12

  Electricity · mapped topic

• H01L43/08

  Electricity · mapped topic

• H01L27/226

  Electricity · mapped topic