Multilayer thin films exhibiting perpendicular magnetic anisotropy

Patent metadata

Field	Value
Publication number	US-10858730-B2
Application number	US-201715599259-A
Country	US
Kind code	B2
Filing date	May 18, 2017
Priority date	Dec 14, 2016
Publication date	Dec 8, 2020
Grant date	Dec 8, 2020

Abstract

A method for forming a multilayer thin film exhibiting perpendicular magnetic anisotropy includes alternately sputtering a CoFeSiB target and a Pd target inside a vacuum chamber to form a [CoFeSiB/Pd] multilayer thin film on a substrate disposed inside the vacuum chamber. The number of times the [CoFeSiB/Pd] multilayer thin film is stacked may be 3 or more.

First claim

What is claimed is:

1. A method for forming a CoFeSiB/Pd multilayer thin film exhibiting perpendicular magnetic anisotropy, the method comprising:
alternate sputtering a CoFeSiB target and a Pd target inside a vacuum chamber to form the [CoFeSiB/Pd] multilayer thin film on a substrate disposed inside the vacuum chamber, and performing a post-deposition annealing after forming the [CoFeSiB/Pd] multilayer thin film;
wherein a number of times the [CoFeSiB/Pd] multilayer thin film is stacked is 3 or more;
wherein the method further comprises forming a buffer layer before forming the [CoFeSiB/Pd] multilayer thin film, wherein the buffer layer is Pd and has a thickness of 3 nm or more;
wherein the post-deposition annealing temperature is 400 degrees Celsius or more; and
wherein the [CoFeSiB/Pd] multilayer film has a squareness of 90 percent or more, a saturation magnetization of 300 emu/cm 3 or more, an effective magnetic anisotropy energy of 1.0×10 6 erg/cm 3 or more, and a coercivity of 3 kOe or more.

2. The method as set forth in claim 1 , further comprising:
forming a seed layer before forming the buffer layer; and
forming a capping layer after forming the [CoFeSiB/Pd] multilayer thin film.

3. The method as set forth in claim 1 , wherein the [CoFeSiB/Pd] multilayer thin film is formed by dc sputtering using the CoFeSiB target and the Pd target.

4. The method as set forth in claim 3 , wherein a composition ratio of the CoFeSiB target is Co x Fe y Si 15 B 10 (atomic percent), and x=70.5˜75 and y=4.5˜0.

5. The method as set forth in claim 3 , wherein the [CoFeSiB/Pd] multilayer thin film is deposited under an atmosphere of argon and an atmosphere of 1 mTorr to 10 mTorr.

6. The method as set forth in claim 3 , wherein a ratio of a thickness of CoFeSiB to a thickness of Pd is 1:1.6 to 1:7.

Assignees

• Univ Korea Res & Bus Found

Inventors

• Kim Young Keun
• Kim Yong Jin

Classifications

• H10N50/85

  Materials of the active region · CPC title

• H01F10/142

  containing Si · CPC title

• C23C14/165

  by cathodic sputtering · CPC title

• H01F10/3236 Primary

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

• H01F41/18

  by cathode sputtering · CPC title