Perpendicular magnetization film, perpendicular magnetization film structure, magnetoresistance element, and perpendicular magnetic recording medium

Patent metadata

Field	Value
Publication number	US-9842636-B2
Application number	US-201615134514-A
Country	US
Kind code	B2
Filing date	Apr 21, 2016
Priority date	Apr 23, 2015
Publication date	Dec 12, 2017
Grant date	Dec 12, 2017

Abstract

Provided is a structure having a perpendicular magnetization film which is an (Mn 1-x Ga x ) 4 N 1-y (0<x≦0.5, 0<y<1) thin film having a nitrogen-deficient composition which is formed by controlling and introducing nitrogen N into an MnGa alloy or a thin film containing at least one of Ge, Zn, Sb, Ni, Ag, Sn, Pt, and Rh, instead of Ga. The perpendicular magnetization film exhibits a Curie temperature sufficiently higher than room temperature, has saturation magnetization smaller than that of existing materials, and is capable of being fabricated as a very flat film.

First claim

The invention claimed is:

1. A perpendicular magnetization film having
a composition consisting essentially of
(Mn 1-x M x ) 4 N 1-y

wherein M is selected from the group consisting of Ga, Ge, Zn, Sb, Ni, Ag, and Pt, and mixtures thereof, and
wherein 0<x≦0.5 and 0<y<1,
and a perovskite type crystal structure.

2. The perpendicular magnetization film according to 1 , wherein the metal element M is Ga or Ge.

3. The perpendicular magnetization film according to claim 1 , wherein vapor deposition is made on a substrate or through an underlayer on a substrate.

4. A perpendicular magnetization film structure having a structure in which the perpendicular magnetization film according to claim 1 is laminated on the substrate or through the underlayer on the substrate.

5. The perpendicular magnetization film structure according to claim 4 , wherein the substrate is a single crystal substrate with a cubic structure grown in an (001) orientation or an orientation film with a cubic structure which is grown in the (001) orientation.

6. The perpendicular magnetization film structure according to claim 4 , wherein the underlayer is a nonmagnetic layer or an electric conductive layer and is made through single crystal growth.

7. The perpendicular magnetization film structure according to claim 4 , wherein a non-magnetic layer is laminated on the perpendicular magnetization film in a perpendicular magnetization film structure.

8. A perpendicular tunnel magnetoresistance (MTJ) element structure comprising:
the perpendicular magnetization film in the perpendicular magnetization film structure according to claim 4 being used as a first perpendicular magnetization layer, a tunnel barrier layer thereon; and
a perpendicular magnetization layer which is the same type as or different type from the perpendicular magnetization film being laminated as a second perpendicular magnetization layer.

9. The perpendicular tunnel magnetoresistance (MTJ) element structure according to claim 8 , wherein the element structure has an upper electrode on the second perpendicular magnetization film layer.

10. A perpendicular magnetic recording medium including the perpendicular magnetization film structure according to claim 4 , being at least of a part thereof.

11. A fabrication method of a perpendicular magnetization film, wherein the perpendicular magnetization film having the composition expressed in claim 1 , is formed on a substrate by a vapor deposition method.

12. The fabrication method of a perpendicular magnetization film according to claim 11 , wherein the vapor deposition method is a radio frequency (RF) reactive sputter, a DC reactive sputter, an electron beam evaporation, a simultaneous sputter of Mn and metal M, a simultaneous evaporation of Mn and metal M, a reactive evaporation or a reactive sputter using nitrogen radical source, or a direct deposition using an Mn-M-N target in which a nitrogen composition is adjusted.

Assignees

• Nat Inst Materials Science
• Samsung Electronics Co Ltd

Inventors

• Sukegawa Hiroaki
• Lee Hwachol
• Hono Kazuhiro
• Mitani Seiji
• Ohkubo Tadakatsu
• Liu Jun
• Kasai Shinya
• Kim Kwangseok

Classifications

• H01F10/1933

  Perovskites · CPC title

• H01F10/3286

  Spin-exchange coupled multilayers having at least one layer with perpendicular magnetic anisotropy · CPC title

• G11C11/161 Primary

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

• G11C11/16

  using elements in which the storage effect is based on magnetic spin effect · CPC title

• H10B61/00

  Magnetic memory devices, e.g. magnetoresistive RAM [MRAM] devices · CPC title