US-20260130119-A1 - MAGNETORESISTANCE EFFECT ELEMENT

US20260130119A1US 20260130119 A1US20260130119 A1US 20260130119A1US-20260130119-A1

Abstract

A magnetoresistive effect element includes a first ferromagnetic layer, a second ferromagnetic layer, a non-magnetic layer disposed between the first ferromagnetic layer and the second ferromagnetic layer, and an additive-containing layer disposed at any position in a laminating direction, at least one of the first ferromagnetic layer and the second ferromagnetic layer is a Heusler alloy containing at least one of boron and carbon, at least part of which is crystallized, and the additive-containing layer is a non-magnetic layer containing at least one of boron and carbon, and any one element selected from the group made of Ti, V, Cr, Cu, Zn, Zr, Mo, Ru, Pd, Ta, W, Ir, Pt and Au.

Inventors

Shinto ICHIKAWA
Kazuumi INUBASHI
Katsuyuki Nakada

Assignees

TDK CORPORATION

Dates

Publication Date: 20260507
Application Date: 20251219

Claims (14)

1 . A magnetoresistive effect element comprising: a first ferromagnetic layer, a second ferromagnetic layer, a non-magnetic layer disposed between the first ferromagnetic layer and the second ferromagnetic layer, an intermediate layer, and an additive-containing layer disposed at any position in a laminating direction, wherein at least one of the first ferromagnetic layer and the second ferromagnetic layer is a Heusler alloy containing at least one of boron and carbon, and the additive-containing layer is a non-magnetic layer containing both boron and carbon, and Ru.
2 . The magnetoresistive effect element according to claim 1 , wherein the additive-containing layer is two layers, and the two additive-containing layers sandwich the first ferromagnetic layer and the second ferromagnetic layer.
3 . The magnetoresistive effect element according to claim 1 , wherein the additive-containing layer is in contact with at least one of the first ferromagnetic layer and the second ferromagnetic layer.
4 . The magnetoresistive effect element according to claim 1 , wherein, in the first ferromagnetic layer or the second ferromagnetic layer, a concentration of boron or carbon in a first surface close to the non-magnetic layer is lower than a concentration of boron or carbon in a second surface far from the non-magnetic layer.
5 . The magnetoresistive effect element according to claim 1 , wherein, in the first ferromagnetic layer or the second ferromagnetic layer, a concentration of boron or carbon is lower as it becomes closer to the non-magnetic layer.
6 . The magnetoresistive effect element according to claim 1 , wherein, in the Heusler alloy, a compound expressed by Co α Y β Z γ contains at least one of boron and carbon, Y is a transition metal element or a precious metal element of the Co, Fe, Ni, Cu, Mn, V, Cr or Ti group, and Z is a typical element from group III to group V, and α is 1 or 2 and β+γ>2 is satisfied.
7 . The magnetoresistive effect element according to claim 1 , wherein the Heusler alloy is a compound expressed by (Co 2 Fe β Z γ ) 1-δ B δ , Z is a typical element from group III to group V, and β+γ>2.3, β<γ, 0.5<β<1.9, 1.0<γ<2.0, and 0.1≤δ≤0.3 are satisfied.
8 . The magnetoresistive effect element according to claim 7 , wherein the compound satisfies 0.1≤δ≤0.25.
9 . The magnetoresistive effect element according to claim 1 , wherein the additive-containing layer is discontinuous in an in-plane direction crossing the laminating direction.
10 . The magnetoresistive effect element according to claim 1 , wherein the non-magnetic layer is a metal or an alloy containing any one element selected from the group consisting of Cu, Au, Ag, Cr and Al.
11 . The magnetoresistive effect element according to claim 1 , further comprising an intermediate layer, wherein the intermediate layer is disposed at least one of between the first ferromagnetic layer and the non-magnetic layer and between the second ferromagnetic layer and the non-magnetic layer, the intermediate layer is an alloy expressed by Ni or Ni ε Al 1-ε , and 0.5 ≤ ε < 1. .
12 . The magnetoresistive effect element according to claim 11 , wherein a thickness of the intermediate layer is greater than 0 nm, and equal to or smaller than 0.63 nm.
13 . The magnetoresistive effect element according to claim 1 , further having a substrate, wherein the substrate is a backing on which the first ferromagnetic layer, the second ferromagnetic layer, the non-magnetic layer and the additive-containing layer are laminated, and the substrate is amorphous.
14 . The magnetoresistive effect element according to claim 1 , further comprising an intermediate layer, wherein the intermediate layer is disposed at least one of between the first ferromagnetic layer and the non-magnetic layer and between the second ferromagnetic layer and the non-magnetic layer, the intermediate layer is an alloy expressed by Ni ε Al 1-ε , and 0.5 ≤ ε < 1. .

Description

This application is a continuation application of U.S. patent application Ser. No. 17/116,236 filed Dec. 9, 2020, now allowed, which is a continuation in part of PCT/JP2019/049843, filed Dec. 19, 2019, incorporated herein by reference in its entirety. TECHNICAL FIELD The present invention relates to a magnetoresistive effect element and a crystallization method of a ferromagnetic layer. BACKGROUND ART A magnetoresistive effect element is an element having a resistance value in a laminating direction that varies due to a magnetoresistive effect. The magnetoresistive effect element includes two ferromagnetic layers and a non-magnetic layer sandwiched therebetween. The magnetoresistive effect element having a conductor used in the non-magnetic layer is referred to as a giant magnetoresistance (GMR) element, and the magnetoresistive effect element having an insulating layer (a tunnel barrier layer, a barrier layer) used in the non-magnetic layer is referred to as a tunnel magnetoresistance (TMR) element. The magnetoresistive effect element can be applied in various uses of a magnetic sensor, high frequency parts, a magnetic head, a nonvolatile random access memory (MRAM), and the like. Patent Literature 1 discloses a magnetic sensor including a magnetoresistive effect element having a Heusler alloy used in a ferromagnetic layer. The Heusler alloy has high spin polarizing efficiency, and is expected to increase an output signal of a magnetic sensor. Patent Literature 1 discloses that the Heusler alloy does not easily crystallize unless film forming is performed on a thick backing substrate having a predetermined crystalline property or at a high temperature. Patent Literature 1 discloses that film forming at a high temperature and a thick backing substrate can cause a decrease in output of the magnetic sensor. Patent Literature 1 discloses that output of the magnetic sensor is increased by setting the ferromagnetic layer as a laminated structure of an amorphous layer and a crystalline layer. CITATION LIST Patent Literature [Patent Literature 1] U.S. Pat. No. 9,412,399 SUMMARY OF INVENTION Technical Problem The magnitude of an output signal of a magnetic sensor depends on a magnetoresistive change ratio (MR ratio) of a magnetoresistive effect element. In general, one having higher crystalline properties of ferromagnetic layers sandwiching a non-magnetic layer tends to have a larger MR ratio. In the magnetoresistive effect element disclosed in Patent Literature 1, the ferromagnetic layer in contact with the non-magnetic layer is amorphous, and it is difficult to obtain a sufficiently large MR ratio. In consideration of the above-mentioned circumstances, the present invention is directed to providing a magnetoresistive effect element capable of realizing a large MR ratio. In addition, the present invention is directed to providing a crystallization method of a ferromagnetic layer used in the magnetoresistive effect element. Solution to Problem In order to achieve the aforementioned objects, the present invention provides the following means. (1) A magnetoresistive effect element according to a first aspect includes a first ferromagnetic layer, a second ferromagnetic layer, a non-magnetic layer disposed between the first ferromagnetic layer and the second ferromagnetic layer, and an additive-containing layer disposed at any position in a laminating direction, wherein at least one of the first ferromagnetic layer and the second ferromagnetic layer is a Heusler alloy containing at least one of boron and carbon, at least part of which is crystallized, and the additive-containing layer is a non-magnetic layer containing: at least one of boron and carbon, and any one element selected from the group consisting of Ti, V, Cr, Cu, Zn, Zr, Mo, Ru, Pd, Ta, W, Ir, Pt and Au.(2) In the magnetoresistive effect element according to the aspect, the additive-containing layer may be two layers, and the two additive-containing layers may sandwich the first ferromagnetic layer and the second ferromagnetic layer.(3) In the magnetoresistive effect element according to the aspect, the additive-containing layer may be in contact with at least one of the first ferromagnetic layer and the second ferromagnetic layer.(4) In the first ferromagnetic layer or the second ferromagnetic layer of the magnetoresistive effect element according to the aspect, a concentration of boron or carbon in a first surface close to the non-magnetic layer may be lower than a concentration of boron or carbon in a second surface far from the non-magnetic layer.(5) In the first ferromagnetic layer or the second ferromagnetic layer of the magnetoresistive effect element according to the aspect, a concentration of boron or carbon may be lower as it becomes closer to the non-magnetic layer.(6) In the magnetoresistive effect element according to the aspect, the additive-containing layer may be a metal or an alloy containing at least one of boron and carbon, and co