Platinum and cobalt/copper-based multilayer thin film having low saturation magnetization and fabrication method thereof

Patent metadata

Field	Value
Publication number	US-2017133583-A1
Application number	US-201715410535-A
Country	US
Kind code	A1
Filing date	Jan 19, 2017
Priority date	May 22, 2012
Publication date	May 11, 2017
Grant date	—

Abstract

A multilayer thin film for magnetic random access memory that includes thin platinum layers and thin cobalt-copper layers, and more particularly, to a multilayer thin film having magnetic layers including non-magnetic material copper that replaces a portion of the magnetic material cobalt.

First claim

What is claimed is:

1 . A perpendicular magnetic anisotropy multilayer thin film for magnetic random access memory, comprising:
a thin platinum layer and a thin cobalt-copper layer alternately deposited to form a multilayer thin film over a substrate, wherein the cobalt-copper layer is thicker than the thin platinum layer.

2 . The perpendicular magnetic anisotropy multilayer thin film of claim 1 , wherein a content ratio of cobalt:copper in the thin cobalt-copper layers is 50:50 to 90:10 (atomic ratio).

3 . The perpendicular magnetic anisotropy multilayer thin film of claim 1 , wherein the multilayer thin film including the thin platinum layer and the thin cobalt-copper layer is repeatedly stacked over the substrate 2-10 turns.

4 . The perpendicular magnetic anisotropy multilayer thin film of claim 1 , wherein the multilayer thin film has a total thickness of 0.3-12.5 nm.

5 . The perpendicular magnetic anisotropy multilayer thin film of claim 4 , wherein a thickness of the thin platinum layer in the multilayer thin film ranges from 0.15 nm to 0.25 nm.

6 . The perpendicular magnetic anisotropy multilayer thin film of claim 1 , wherein the thickness ratio of the thin cobalt-copper layer to the thin platinum layer is 1.1-4:1.

7 . The perpendicular magnetic anisotropy multilayer thin film of claim 1 , further comprising:
a stack of a buffer layer and a seed layer, which are provided between the substrate and the multilayer thin film, and a protective layer deposited over the multilayer thin film.

8 . The perpendicular magnetic anisotropy multilayer thin film of claim 7 , wherein each of the buffer layer, the seed layer, and the protective layer independently includes gold (Au), palladium (Pd), copper (Cu), platinum (Pt), tantalum (Ta), ruthenium (Ru), or a combination thereof.

9 . The perpendicular magnetic anisotropy multilayer thin film of claim 1 , wherein the multilayer thin film has a perpendicular magnetic anisotropy (PMA) energy density of 0.23˜5.66×10 6 erg/cm 3 at 300˜500 Celsius degrees.

Assignees

• Sk Hynix Inc

Inventors

• Lim Sang-Ho
• Son Dong-Su
• Lee Tae-Young
• Lee Seong-Rae

Classifications

• H01F10/3222

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

• H01L43/08

  Electricity · mapped topic

• H01L27/222

  Electricity · mapped topic

• H01L43/10 Primary

  Electricity · mapped topic

• H01F10/3236

  made of a noble metal, e.g.(Co/Pt) n multilayers having perpendicular anisotropy (H01F10/3286 takes precedence) · CPC title