Giant magnetoresistance element and current sensor using the same

Patent metadata

Field	Value
Publication number	US-9523746-B2
Application number	US-201514789781-A
Country	US
Kind code	B2
Filing date	Jul 1, 2015
Priority date	Feb 4, 2013
Publication date	Dec 20, 2016
Grant date	Dec 20, 2016

Abstract

A GMR element includes a fixed magnetic layer in which magnetization is fixed; a free magnetic layer in which magnetization is changed by an external magnetic field; and a spacer layer which is positioned between the fixed magnetic layer and the free magnetic layer, in which the free magnetic layer is formed by laminating a CoFe alloy and a CoFeB alloy. A current sensor uses the GMR element.

First claim

What is claimed is:

1. A giant magnetoresistance element comprising:
a fixed magnetic layer in which magnetization is fixed;
a free magnetic layer in which magnetization is changed by an external magnetic field; and
a spacer layer disposed between the fixed magnetic layer and the free magnetic layer,
wherein the free magnetic layer is a laminated layer formed of a CoFe alloy film and a CoFeB alloy film, and
a thickness of the CoFe alloy film is equal to or greater than 2 nm and equal to or smaller than 4 nm, and a thickness of the CoFeB alloy film is equal to or greater than 5 nm and equal to or smaller than 14 nm or less.

2. The giant magnetoresistance element according to claim 1 ,
wherein the CoFeB alloy film has an amorphous structure.

3. The giant magnetoresistance element according to claim 1 ,
wherein a composition of the CoFe alloy film is represented by Co X Fe 100−X and a composition of the CoFeB alloy film is represented by (Co Y Fe 100−Y ) 100−Z B Z , where X satisfies 80 atom %≦X<100 atom %, Y satisfies 80 atom %≦Y<100 atom %, and Z satisfies 10 atom %≦Z≦30 atom %.

4. A current sensor comprising: the giant magnetoresistance element according to claim 1 .

Assignees

• Alps Electric Co Ltd

Inventors

• Ide Yosuke

Classifications

• G01R15/205

  using magneto-resistance devices, e.g. field plates · CPC title

• G01R33/093 Primary

  using multilayer structures, e.g. giant magnetoresistance sensors (thin magnetic films H01F10/00) · CPC title

• G11B5/3903

  using magnetic thin film layers or their effects, the films being part of integrated structures · CPC title

• G11B2005/3996

  large or giant magnetoresistive effects [GMR], e.g. as generated in spin-valve [SV] devices · CPC title

• H01L43/08

  Electricity · mapped topic