MAGNETIC RANDOM ACCESS MEMORY WITH PERPENDICULAR ENHANCEMENT LAYER

• US 20180076384A1
• Filed: 11/17/2017
• Published: 03/15/2018
• Est. Priority Date: 09/14/2010
• Status: Active Grant

• Current Assignee: Avalanche Technology Incorporated
• Original Assignee: Avalanche Technology Incorporated
• Inventors: Gan, Huadong, Huai, Yiming, Zhou, Yuchen, Wang, Zihui, Yen, Bing K., Hao, Xiaojie, Xu, Pengfa
• Granted Patent: US 10,032,979 B2
• Time in Patent Office: Days
• CPC Class Codes: B82Y 40/00 Manufacture or treatment of nanostructures
• CPC Class Codes: G11C 11/16 using elements in which the storage effect is based on magnetic spin effect
• CPC Class Codes: G11C 11/161 details concerning the memory cell structure, e.g. the layers of the ferromagnetic memory cell
• CPC Class Codes: H01F 10/3286 Spin-exchange coupled multilayers having at least one layer with perpendicular magnetic anisotropy
• CPC Class Codes: H01F 10/329 Spin-exchange coupled multilayers wherein the magnetisation of the free layer is switched by a spin-polarised current, e.g. spin torque effect
• CPC Class Codes: H01F 41/302 for applying spin-exchange-coupled multilayers, e.g. nanostructured superlattices spin-exchange-coupled multilayers H01F10/32
• CPC Class Codes: H01L 29/66984 Devices using spin polarized carriers
• CPC Class Codes: H10B 61/22 of the field-effect transistor [FET] type
• CPC Class Codes: H10N 50/10 Magnetoresistive devices
• CPC Class Codes: H10N 50/80 Constructional details
• CPC Class Codes: H10N 50/85 Magnetic active materials

Abstract

The present invention is directed to a magnetic memory element including a magnetic free layer structure having a variable magnetization direction perpendicular to a layer plane thereof; an insulating tunnel junction layer formed adjacent to the magnetic free layer structure; a first magnetic reference layer comprising cobalt, iron, and boron formed adjacent to the insulating tunnel junction layer; a second magnetic reference layer comprising cobalt separated from the first magnetic reference layer by a molybdenum layer; an iridium layer formed adjacent to the second magnetic reference layer; and a magnetic fixed layer structure formed adjacent to the iridium layer. The magnetic free layer structure includes a first and a second magnetic free layers with a perpendicular enhancement layer interposed therebetween. The first and second magnetic reference layers have a first invariable magnetization direction perpendicular to layer planes thereof. The magnetic fixed layer structure has a second invariable magnetization direction opposite to the first invariable magnetization direction.

Claims

1. A magnetic memory element comprising:

a magnetic free layer structure including a first magnetic free layer and a second magnetic free layer with a first perpendicular enhancement layer (PEL) interposed therebetween, said first and second magnetic free layers having a same variable magnetization direction substantially perpendicular to layer planes of said first and second magnetic free layers;

an insulating tunnel junction layer formed adjacent to said first magnetic free layer;

a magnetic reference layer structure including a first magnetic reference layer comprising cobalt, iron, and boron formed adjacent to said insulating tunnel junction layer, a second magnetic reference layer comprising cobalt, and a second perpendicular enhancement layer (PEL) comprising molybdenum interposed between said first and second magnetic reference layers, said first and second magnetic reference layers having a first fixed magnetization direction substantially perpendicular to layer planes of said first and second magnetic reference layers;

an iridium layer formed adjacent to said second magnetic reference layer opposite said second perpendicular enhancement layer; and

a magnetic fixed layer structure formed adjacent to said iridium layer opposite said magnetic reference layer structure, said magnetic fixed layer structure being anti-ferromagnetically coupled to said magnetic reference layer structure and having a second fixed magnetization direction that is substantially perpendicular to a layer plane of said magnetic fixed layer structure and is substantially opposite to said first fixed magnetization direction.

2. The magnetic memory element according to claim 1, wherein said second magnetic reference layer further comprises iron.

3. The magnetic memory element according to claim 1, wherein said second magnetic reference layer further comprises iron and boron.

4. The magnetic memory element according to claim 1, wherein said first magnetic free layer comprises cobalt, iron, and boron.

5. The magnetic memory element according to claim 1, wherein said second magnetic free layer comprises cobalt and iron.

6. The magnetic memory element according to claim 1, wherein said second magnetic free layer comprises cobalt, iron, and boron.

7. The magnetic memory element according to claim 1, wherein said first perpendicular enhancement layer comprises molybdenum.

8. The magnetic memory element according to claim 1, wherein said first perpendicular enhancement layer comprises iridium.

9. The magnetic memory element according to claim 1, wherein said insulating tunnel junction layer comprises magnesium oxide.

10. The magnetic memory element according to claim 1, wherein said magnetic fixed layer structure includes a magnetic layer comprising cobalt and platinum.

11. The magnetic memory element according to claim 1, wherein said magnetic fixed layer structure includes a magnetic layer comprising iron and platinum.

12. The magnetic memory element according to claim 1, wherein said magnetic fixed layer structure includes 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.

13. The magnetic memory element according to claim 12, wherein said first material is cobalt and said second material is nickel.

14. The magnetic memory element according to claim 12, wherein said first material is cobalt and said second material is platinum or palladium.

15. The magnetic memory element according to claim 1, further comprising a magnesium oxide layer formed adjacent to said second magnetic free layer opposite said first perpendicular enhancement layer.

16. The magnetic memory element according to claim 1, further comprising a hafnium oxide layer formed adjacent to said second magnetic free layer opposite said first perpendicular enhancement layer.

17. The magnetic memory element according to claim 1, further comprising another iridium layer formed adjacent to said second magnetic free layer opposite said first perpendicular enhancement layer.

18. The magnetic memory element according to claim 1, further comprising another iridium layer formed adjacent to said magnetic fixed layer structure opposite said iridium layer.

19. The magnetic memory element according to claim 1, further comprising a metal layer formed adjacent to said magnetic fixed layer structure opposite said iridium layer, wherein said metal layer comprises nickel and titanium.

20. The magnetic memory element according to claim 1, further comprising a metal layer formed adjacent to said magnetic fixed layer structure opposite said iridium layer, wherein said metal layer comprises nickel and iridium.