Magnetoresistive devices and methods therefor

Patent metadata

Field	Value
Publication number	US-12563974-B2
Application number	US-202418665145-A
Country	US
Kind code	B2
Filing date	May 15, 2024
Priority date	Oct 18, 2018
Publication date	Feb 24, 2026
Grant date	Feb 24, 2026

Abstract

Aspects of the present disclosure are directed to magnetoresistive stacks including regions having increased height-to-diameter ratios. Exemplary magnetoresistive stacks (for example, used in a magnetic tunnel junction (MTJ) magnetoresistive device) of the present disclosure include one or more multilayer synthetic antiferromagnetic structures (SAFs) or synthetic ferromagnetic structures (SyFs) in order to promote stability of the SAF or SyF, e.g., for smaller-sized MTJs.

First claim

What is claimed is:

1 . A magnetic tunnel junction (MTJ) bit, comprising:
a synthetic antiferromagnetic (SAF) fixed region including:
a first anti-parallel region and a second anti-parallel region; and
a coupling region, wherein the coupling region is disposed between the first and second anti-parallel regions, and wherein a height of the SAF fixed region is greater than or equal to a width of the SAF fixed region; and
a free region including a second coupling region, the second coupling region including a synthetic antiferromagnetic coupling region and a synthetic ferromagnetic coupling region.

2 . The MTJ bit of claim 1 , wherein the SAF fixed region comprises at least four anti-parallel regions.

3 . The MTJ bit of claim 1 , wherein the height of the SAF fixed region is greater than approximately 10 nm.

4 . The MTJ bit of claim 1 , wherein the height of the SAF fixed region is between approximately 20 nm and approximately 40 nm.

5 . The MTJ bit of claim 1 ,
wherein a height of the free region is approximately equal to the height of the SAF fixed region.

6 . The MTJ bit of claim 1 , wherein the height of the SAF fixed region is between 1 and 3 times greater than the width of the SAF fixed region.

7 . The MTJ bit of claim 1 , wherein the SAF fixed region is a first SAF fixed region, and further comprising:
a second SAF fixed region including:
two anti-parallel regions; and
a coupling region disposed between the two anti-parallel regions;
wherein the first SAF fixed region and the second SAF fixed region are disposed on opposite sides of the free region.

8 . The MTJ bit of claim 1 , wherein the coupling region includes one of iridium, ruthenium, rhenium, or rhodium.

9 . The MTJ bit of claim 1 , wherein the SAF fixed region is a first SAF fixed region, and the MTJ bit further comprises:
a second SAF fixed region including:
two anti-parallel regions; and
a coupling region disposed between the two anti-parallel regions,
wherein the coupling region of the second SAF fixed region includes one of iridium, ruthenium, rhenium, or rhodium.

10 . A magnetic tunnel junction (MTJ) bit, comprising:
a synthetic antiferromagnetic (SAF) fixed region including:
a first anti-parallel region and a second anti-parallel region, wherein each of the first and second anti-parallel regions comprises one or more layers of a first ferromagnetic material and a second ferromagnetic material; and
a coupling region,
wherein the coupling region is disposed between the first and second anti-parallel regions; and
a free region including one or more synthetic antiferromagnetic coupling regions and one or more synthetic ferromagnetic coupling regions.

11 . The MTJ bit of claim 10 , wherein the SAF fixed region comprises at least four anti-parallel regions.

12 . The MTJ bit of claim 10 , wherein each of the first ferromagnetic material and the second ferromagnetic material comprises at least one of cobalt, nickel and iron.

13 . The MTJ bit of claim 10 , wherein each of the first and second anti-parallel regions further comprises an alloy or engineered material including one or more of palladium, platinum, magnesium, manganese, and chromium.

14 . The MTJ bit of claim 10 , wherein a width of the MTJ bit is between approximately 10 nm and approximately 30 nm.

15 . A magnetic tunnel junction (MTJ) bit, comprising:
a synthetic antiferromagnetic (SAF) fixed region including:
a first anti-parallel region and a second anti-parallel region; and
a first coupling region, wherein the first coupling region is disposed between the first and second anti-parallel regions;
a free region, including:
a first ferromagnetic region and a second ferromagnetic region; and
a second coupling region, wherein the second coupling region includes one or more synthetic antiferromagnetic coupling regions and one or more synthetic ferromagnetic coupling regions, wherein the second coupling region is disposed between the first and second ferromagnetic regions; and
an intermediate region disposed between the SAF fixed region and the free region, wherein a height of the SAF fixed region is greater than or equal to a width of the SAF fixed region, and a height of the free region is greater than or equal to a width of the free region.

16 . The MTJ bit of claim 15 , wherein the free region includes exactly one synthetic antiferromagnetic coupling region.

17 . The MTJ bit of claim 15 , wherein the free region includes no more than two synthetic ferromagnetic coupling regions.

18 . The MTJ bit of claim 15 , wherein the free region includes the one or more synthetic antiferromagnetic coupling regions and the one or more synthetic ferromagnetic coupling regions in an alternating configuration.

19 . The MTJ bit of claim 15 , wherein the second coupling region in the free region includes one of aluminum, magnesium, tantalum, titanium, vanadium, chromium, zirconium, niobium, molybdenum, hafnium, tungsten, iridium, ruthenium, palladium, rhenium, rhodium, osmium, platinum, or an alloy thereof.

20 . The MTJ bit of claim 15 , wherein the height of the free region is approximately equal to the height of the SAF fixed region.

Assignees

• Everspin Technologies Inc

Inventors

• Sun Jijun

Classifications

• H10N50/85

  Materials of the active region · CPC title

• H10N50/80

  Constructional details · CPC title

• H10N50/01 Primary

  Manufacture or treatment · CPC title

• H10B61/20

  comprising components having three or more electrodes, e.g. transistors · CPC title

• G11C11/161

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