Spin valve magnetoresistance element with improved response to magnetic fields

Patent metadata

Field	Value
Publication number	US-2016359103-A1
Application number	US-201615165322-A
Country	US
Kind code	A1
Filing date	May 26, 2016
Priority date	Jun 5, 2015
Publication date	Dec 8, 2016
Grant date	—

Abstract

A spin valve magnetoresistance element has an even number of free layer structures for which half has an antiferromagnetic coupling and the other half has a ferromagnetic coupling with respect to associated pinned layers. The different couplings are the result of an even number different spacer layers having respective different thicknesses.

First claim

What is claimed is:

1 . A magnetoresistance element deposited upon a substrate, comprising:
an even number of free layer structures, the even number of free layer structures comprising first and second free layer structures; an even number of spacer layers, the even number of spacer layers comprising first and second spacer layers; and an even number of pinned layers structures, the even number of pinned layer structures comprising first and second pinned layer structures, wherein the even number of free layer structures, the even number of spacer layers, and the even number of pinned layer structures are disposed in a stack of layers, wherein a first spacer layers is comprised of a first material with a first thickness, the first material and the first thickness selected to result in a first selected one of an antiferromagnetic coupling or a ferromagnetic coupling between the first pinned layer structures and the first free layer structure, and wherein the second spacer layer is comprised of a second material with a second thickness, the second material and the second thickness selected result in a second selected one of an antiferromagnetic coupling or a ferromagnetic coupling between the second pinned layer structures and the second free layer structures.

2 . The magnetoresistance element of claim 1 , wherein the first and second spacer layers are comprised of Ru.

3 . The magnetoresistance element of claim 2 , wherein the first selected thickness is in the range of about 1.0 nm to about 1.7 nm or about 2.3 nm to about 3.0 nm, and wherein the second selected thickness is in the range of about 1.7 nm to about 2.3 nm or about 3.0 nm to about 3.7 nm.

4 . The magnetoresistance element of claim 2 , wherein the second selected thickness is in the range of about 1.0 nm to about 1.7 nm or about 2.3 nm to about 3.0 nm, and wherein the first selected thickness is in the range of about 1.7 nm to about 2.3 nm or about 3.0 nm to about 3.7 nm.

5 . The magnetoresistance element of claim 2 , wherein the first and second pinned layer structures each consist of one respective pinned layer.

6 . The magnetoresistance element of claim 2 , wherein the first and second pinned layer structures each comprise a respective synthetic antiferromagnetic (SAF) structure.

7 . The magnetoresistance element of claim 1 , wherein the first and second pinned layer structures each consist of one respective pinned layer.

8 . The magnetoresistance element of claim 1 , wherein the first and second pinned layer structures each comprise a respective synthetic antiferromagnetic (SAF) structure.

9 . The magnetoresistance element of claim 1 , further comprising:
an odd number of pinning layers comprising at least first, second, and third pinning layers, the first and second pinning layers magnetically coupled to the first and second pinned layer structures, respectively; wherein the even number of pinned layer structures further comprise third and fourth pinned layer structures, wherein the third pinning layers is a common pinning layer magnetically coupled to both of the third and fourth pinned layer structures.

10 . The magnetoresistance element of claim 9 , wherein the first and second pinning layers are comprised of PtMn.

11 . The magnetoresistance element of claim 10 , wherein the third pinning layer is comprised of PtMn.

12 . The magnetoresistance element of claim 11 , wherein annealed magnetic directions of the first and second pinning layers are parallel to each other, and wherein an annealed magnetic direction of the third pinning layer is ninety degrees relative to the annealed magnetic directions of the first and second pinning layers.

13 . The magnetoresistance element of claim 9 , wherein at least a portion of the magnetoresistance element has a yoke shape.

14 . The magnetoresistance element of claim 13 , wherein a length (L) of the yoke shape and a length (d) of the lateral arms of the yoke shape are each at least three times a width (w) of the yoke shape, and the width (w) of the yoke shape is between about one μm and about twenty μm, wherein the length (L) is a longest dimension of the yoke shape.

15 . A method of fabricating a magnetoresistance element, comprising:
depositing the magnetoresistance element upon a substrate, the magnetoresistance element comprising:
an even number of free layer structures, the even number of free layer structures comprising first and second free layer structures;
an even number of spacer layers, the even number of spacer layers comprising first and second spacer layers; and
an even number of pinned layers structures, the even number of pinned layer structures comprising first and second pinned layer structures, wherein the even number of free layer structures, the even number of spacer layers, and the even number of pinned layer structures are disposed in a stack of layers, wherein a first spacer layers is comprised of a first material with a first thickness, the first material and the first thickness selected to result in a first selected one of an antiferromagnetic coupling or a ferromagnetic coupling between the first pinned layer structures and the first free layer structure, and wherein the second spacer layer is comprised of a second material with a second thickness, the second material and the second thickness selected result in a second selected one of an antiferromagnetic coupling or a ferromagnetic coupling between the second pinned layer structures and the second free layer structures, wherein the method further comprises:
annealing the magnetoresistance element.

16 . The method of claim 15 , wherein the first and second spacer layers are comprised of Ru.

17 . The method of claim 16 , wherein the first selected thickness is in the range of about 1.0 nm to about 1.7 nm or about 2.3 nm to about 3.0 nm, and wherein the second selected thickness is in the range of about 1.7 nm to about 2.3 nm or about 3.0 nm to about 3.7 nm.

18 . The method of claim 16 , wherein the second selected thickness is in the range of about 1.0 nm to about 1.7 nm or about 2.3 nm to about 3.0 nm, and wherein the first selected thickness is in the range of about 1.7 nm to about 2.3 nm or about 3.0 nm to about 3.7 nm.

19 . The method of claim 16 , wherein the first and second pinned layer structures each consist of one respective pinned layer.

20 . The method of claim 16 , wherein the first and second pinned layer structures each comprise a respective synthetic antiferromagnetic (SAF) structure.

21 . The method of claim 15 , wherein the first and second pinned layer structures each consist of one respective pinned layer.

22 . The method of claim 15 , wherein the first and second pinned layer structures each comprise a respective synthetic antiferromagnetic (SAF) structure.

23 . The method of claim 15 , wherein the deposited magnetoresistance element further comprises:
an odd number of pinning layers comprising at least first, second, and third pinning layers, the first and second pinning layers magnetically coupled to the first and second pinned layer structures, respectively; wherein the even number of pinned layer structures further comprise third and fourth pinned layer structures, wherein the third pinning layers is a common pinning layer magnetically coupled to both of the third and fourth pinned layer structures.

24 . The method of claim 23 , wherein the first and second pinning layers are compri

Assignees

• Allegro Microsystems Llc
• Commissariat L Energie Atomique Et Aux Energies Alternatives

Inventors

• Fermon Claude
• Campiglio Paolo
• Cadugan Bryan

Classifications

• G11C11/16

  using elements in which the storage effect is based on magnetic spin effect · CPC title

• H10B61/00

  Magnetic memory devices, e.g. magnetoresistive RAM [MRAM] devices · CPC title

• H01L43/08 Primary

  Electricity · mapped topic

• H01L43/02

  Electricity · mapped topic

• H01L43/12

  Electricity · mapped topic