Top buffer layer for magnetic tunnel junction application

Patent metadata

Field	Value
Publication number	US-10923652-B2
Application number	US-201916448709-A
Country	US
Kind code	B2
Filing date	Jun 21, 2019
Priority date	Jun 21, 2019
Publication date	Feb 16, 2021
Grant date	Feb 16, 2021

Abstract

Embodiments of the disclosure provide methods and apparatus for fabricating magnetic tunnel junction (MTJ) structures on a substrate for MRAM applications. In one embodiment, a magnetic tunnel junction (MTJ) device structure includes a junction structure disposed on a substrate, the junction structure comprising a first ferromagnetic layer and a second ferromagnetic layer sandwiching a tunneling barrier layer, a dielectric capping layer disposed on the junction structure, a metal capping layer disposed on the junction structure, and a top buffer layer disposed on the metal capping layer.

First claim

What is claimed is:

1. A magnetic tunnel junction device structure, comprising:
a substrate;
a seed layer disposed on the substrate;
a pinning layer disposed on the seed layer, the pinning layer comprising a first pinning layer and a second pinning layer sandwiching a coupling layer, wherein the first pinning layer, the second pinning layer, or both comprise Co and Ni;
a junction structure disposed on the seed layer, the junction structure comprising a first ferromagnetic layer and a second ferromagnetic layer sandwiching a tunneling barrier layer;
a dielectric capping layer disposed on the junction structure;
a metal capping layer disposed on the dielectric capping layer; and
a top buffer layer disposed on the metal capping layer.

2. The magnetic tunnel junction device structure of claim 1 , wherein the top buffer layer is amorphous.

3. The magnetic tunnel junction device structure of claim 1 , wherein the top buffer layer is non-magnetic.

4. The magnetic tunnel junction device structure of claim 1 , wherein the top buffer layer is a dielectric material, a metal material, or an insulating material with or without metal dopants.

5. The magnetic tunnel junction device structure of claim 1 , wherein the top buffer layer comprises a CoFeB material.

6. The magnetic tunnel junction device structure of claim 5 , wherein the CoFeB material of the top buffer layer has a boron concentration by atomic weight between about 20% and about 40%.

7. The magnetic tunnel junction device structure of claim 5 , further comprising a metal material disposed below or above the top buffer layer, the metal material being selected from a group consisting of Ta, Mo, W and Cr.

8. The magnetic tunnel junction device structure of claim 1 , further comprising:
a blocking layer disposed between the seed layer and the pinning layer.

9. The magnetic tunnel junction device structure of claim 1 , wherein the metal capping layer is Ru, Ir, a combination thereof, or an alloy thereof.

10. A magnetic tunnel junction device structure, comprising:
a junction structure disposed on a substrate, the junction structure comprising a first ferromagnetic layer and a second ferromagnetic layer sandwiching a tunneling barrier layer;
a dielectric capping layer disposed on the junction structure;
a metal capping layer disposed on the dielectric capping layer;
a metal material disposed on the metal capping layer, the metal material selected from a group consisting of Ta, Mo, W, and Cr; and
a top buffer layer disposed on the metal material, the top buffer layer comprising a CoFeB material.

11. The magnetic tunnel junction device structure of claim 10 , further comprising:
a seed layer disposed on the substrate; and
a pinning layer disposed on the seed layer below the junction structure, the pinning layer comprises a first pinning layer and a second pinning layer sandwiching a coupling layer.

12. The magnetic tunnel junction device structure of claim 11 , wherein the seed layer comprises Cr, Pt, or a combination thereof.

13. The magnetic tunnel junction device structure of claim 12 , wherein when the seed layer comprises Cr, the first pinning layer comprises Co and Ni.

14. The magnetic tunnel junction device structure of claim 12 , wherein the first pinning layer comprises:
Co and Pt; or
Co and Ni.

15. A magnetic tunnel junction device structure, comprising:
a substrate;
a seed layer disposed on the substrate;
a pinning layer disposed on the seed layer, the pinning layer comprising a first pinning layer and a second pinning layer sandwiching a coupling layer, wherein the first pinning layer, the second pinning layer, or both comprise Co and Ni;
a junction structure disposed on the seed layer, the junction structure comprising a first ferromagnetic layer and a second ferromagnetic layer sandwiching a tunneling barrier layer;
a dielectric capping layer disposed on the junction structure;
a metal capping layer disposed on the dielectric capping layer; and
a top buffer layer disposed on the metal capping layer, the top buffer layer comprising a CoFeB material.

16. The magnetic tunnel junction device structure of claim 15 , further comprising a metal material disposed on the metal capping layer and disposed below the top buffer layer, the metal material selected from a group consisting of Ta, Mo, W and Cr.

17. The magnetic tunnel junction device structure of claim 15 , wherein the metal capping layer is Ru, Ir, a combination thereof, or an alloy thereof.

Assignees

• Applied Materials Inc

Inventors

• Xue Lin
• Park Chando
• Ching Chi Hong
• Ahn Jaesoo
• Pakala Mahendra

Classifications

• H10P72/0454 Primary

  surrounding a central transfer chamber · CPC title

• H10P72/3402

  Mechanical parts of transfer devices · CPC title

• H10P72/3302

  Mechanical parts of transfer devices · CPC title

• H10N50/85

  Materials of the active region · CPC title

• H01F41/325

  applying a noble metal capping on a spin-exchange-coupled multilayer, e.g. spin filter deposition · CPC title