Magnetic memory element including oxide/metal composite layers formed adjacent to fixed layer

Patent metadata

Field	Value
Publication number	US-10090456-B2
Application number	US-201715662114-A
Country	US
Kind code	B2
Filing date	Jul 27, 2017
Priority date	Dec 10, 2010
Publication date	Oct 2, 2018
Grant date	Oct 2, 2018

Abstract

The present invention is directed to a magnetic tunnel junction (MTJ) memory element including a magnetic free layer structure and a magnetic reference layer structure with an insulating tunnel junction layer interposed therebetween; a magnetic fixed layer exchange coupled to the magnetic reference layer structure through an anti-ferromagnetic coupling layer; a magnesium oxide layer formed adjacent to the magnetic fixed layer; and a metal layer comprising nickel and chromium formed adjacent to the magnesium oxide layer. The magnetic reference layer structure includes a first and a second magnetic reference layers with a first perpendicular enhancement layer (PEL) interposed therebetween. The first and second magnetic reference layers have a first invariable magnetization direction substantially perpendicular to layer planes thereof. The magnetic fixed layer has a second invariable magnetization direction opposite to the first invariable magnetization direction. The magnetic free layer structure includes one or more magnetic free layers having a variable magnetization direction substantially perpendicular to layer planes thereof.

First claim

What is claimed is:

1. A magnetic tunnel junction (MTJ) memory element comprising:
a magnetic free layer structure and a magnetic reference layer structure with an insulating tunnel junction layer interposed therebetween;
a magnetic fixed layer exchange coupled to said magnetic reference layer structure through an anti-ferromagnetic coupling layer;
a magnesium oxide layer formed adjacent to said magnetic fixed layer opposite said anti-ferromagnetic coupling layer; and
a metal layer comprising nickel and chromium formed adjacent to said magnesium oxide layer opposite said magnetic fixed layer,
wherein said magnetic reference layer structure includes a first magnetic reference layer formed adjacent to said insulating tunnel junction layer and a second magnetic reference layer separated from said first magnetic reference layer by a first perpendicular enhancement layer (PEL), said first and second magnetic reference layers having a first invariable magnetization direction substantially perpendicular to layer planes thereof, said magnetic fixed layer has a second invariable magnetization direction that is substantially perpendicular to a layer plane thereof and is opposite to said first invariable magnetization direction, said magnetic free layer structure includes one or more magnetic free layers having a variable magnetization direction substantially perpendicular to layer planes thereof.

2. The MTJ memory element of claim 1 , wherein said magnetic free layer structure includes a magnetic free layer that comprises cobalt, iron, and boron.

3. The MTJ memory element of claim 1 , wherein said magnetic free layer structure includes a first magnetic free layer formed adjacent to said insulating tunnel junction layer and a second magnetic free layer separated from said first magnetic free layer by a second PEL, said first and said second magnetic free layers having respectively a first and a second variable magnetization directions that are substantially perpendicular to layer planes thereof and are parallel to each other.

4. The MTJ memory element of claim 3 , wherein said first magnetic free layer comprises cobalt, iron, and boron.

5. The MTJ memory element of claim 3 , wherein said second PEL is made of tungsten, molybdenum, tantalum, hafnium, zirconium, niobium, or any combination thereof.

6. The MTJ memory element of claim 1 , wherein said first magnetic reference layer comprises cobalt, iron, and boron.

7. The MTJ memory element of claim 1 , wherein said magnetic fixed layer has a multilayer structure formed by interleaving one or more layers of a first material with one or more layers of a second material, at least one of said first and second materials being magnetic.

8. The MTJ memory element of claim 7 , wherein said first material is cobalt or a material comprising cobalt and iron.

9. The MTJ memory element of claim 7 , wherein said second material is nickel, or platinum, or palladium.

10. A magnetic tunnel junction (MTJ) memory element comprising:
a magnetic free layer structure and a magnetic reference layer structure with an insulating tunnel junction layer interposed therebetween;
a magnetic fixed layer exchange coupled to said magnetic reference layer structure through an anti-ferromagnetic coupling layer;
an oxide layer formed adjacent to said magnetic fixed layer opposite said anti-ferromagnetic coupling layer; and
a metal layer comprising nickel formed adjacent to said oxide layer opposite said magnetic fixed layer,
wherein said magnetic reference layer structure includes a first magnetic reference layer formed adjacent to said insulating tunnel junction layer and a second magnetic reference layer separated from said first magnetic reference layer by a first perpendicular enhancement layer (PEL), said first and second magnetic reference layers having a first invariable magnetization direction substantially perpendicular to layer planes thereof, said magnetic fixed layer has a second invariable magnetization direction that is substantially perpendicular to a layer plane thereof and is opposite to said first invariable magnetization direction, said magnetic free layer structure includes one or more magnetic free layers having a variable magnetization direction substantially perpendicular to layer planes thereof.

11. The MTJ memory element of claim 10 , wherein said oxide layer comprises magnesium.

12. The MTJ memory element of claim 10 , wherein said oxide layer is made of chromium oxide, molybdenum oxide, or tungsten oxide.

13. The MTJ memory element of claim 10 , wherein said oxide layer is made of titanium oxide, zirconium oxide, or hafnium oxide.

14. The MTJ memory element of claim 10 , wherein said oxide layer is made of vanadium oxide, niobium oxide, or tantalum oxide.

15. The MTJ memory element of claim 10 , wherein said metal layer further comprises chromium.

16. The MTJ memory element of claim 10 , wherein said metal layer further comprises titanium.

17. The MTJ memory element of claim 10 , wherein said magnetic free layer structure includes a magnetic free layer that comprises cobalt, iron, and boron.

18. The MTJ memory element of claim 10 , wherein said magnetic fixed layer has a multilayer structure formed by interleaving one or more layers of a first material with one or more layers of a second material, at least one of said first and second materials being magnetic.

19. The MTJ memory element of claim 18 , wherein said first material is cobalt or a material comprising cobalt and iron.

20. The MTJ memory element of claim 18 , wherein said second material is nickel, or platinum, or palladium.

Assignees

• Avalanche Technology Inc

Inventors

• Huai Yiming
• Gan Huadong
• Wang Zihui

Classifications

• H01F10/3222

  Exchange coupled hard/soft multilayers, e.g. CoPt/Co or NiFe/CoSm (nanocomposite spring magnets H01F1/0579) · CPC title

• H01L43/02 Primary

  Electricity · mapped topic

• H01F10/16

  containing cobalt ({H01F10/126} , H01F10/13 take precedence) · CPC title

• H01L27/228

  Electricity · mapped topic

• H01L43/10

  Electricity · mapped topic