Magnetoresistive element and device utilizing magnetoresistance effect

• US 6,724,585 B2
• Filed: 09/20/1999
• Issued: 04/20/2004
• Est. Priority Date: 09/18/1998
• Status: Expired due to Term

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Hayashi, Kazuhiko
• Primary Examiner(s): Korzuch, William
• Assistant Examiner(s): CASTRO, ANGEL A
• Application Number:
  US09/398,773
• Publication Number:
  US 20020167766A1
• Time in Patent Office: 1,674 Days
• Field of Search: 360/324.1, 360/324.11, 360/324.2, 360/326, 360/324.12, 360/324, 365/158
• US Class Current: 360/324.2
• CPC Class Codes: B82Y 25/00 Nanomagnetism, e.g. magnetoimpedance, anisotropic magnetoresistance, giant magnetoresistance or tunneling magnetoresistance
• CPC Class Codes: G01R 33/093 using multilayer structures, e.g. giant magnetoresistance sensors thin magnetic films H01F10/00
• CPC Class Codes: G11B 5/3916 Arrangements in which the active read-out elements are coupled to the magnetic flux of the track by at least one magnetic thin film flux guide
• CPC Class Codes: G11B 5/3967 Composite structural arrangements of transducers, e.g. inductive write and magnetoresistive read G11B5/3906 takes precedence
• CPC Class Codes: H01F 10/3204 Exchange coupling of amorphous multilayers
• CPC Class Codes: H01F 10/3254 the spacer being semiconducting or insulating, e.g. for spin tunnel junction [STJ]
• CPC Class Codes: H01F 10/3268 the exchange coupling being asymmetric, e.g. by use of additional pinning, by using antiferromagnetic or ferromagnetic coupling interface, i.e. so-called spin-valve [SV] structure, e.g. NiFe/Cu/NiFe/FeMn

Abstract

The present invention provides a magnetoresistive device including a multi-layered structure of a free magnetic layer, a non-magnetic non-conductive layer in contact with the free magnetic layer, a pinned layer in contact with the non-magnetic non-conductive layer, and a pinning layer in contact with the pinned layer for pinning a magnetization direction of the pinned layer, wherein at least any one of the free magnetic layer and the pinned layer has an interface region abutting the non-magnetic non-conductive layer, and at least a part of the interface region includes at least one material selected from the group consisting of CoFeB, CoZrMo, CoZrNb, CoZr, CoZrTa, CoHf, CoTa, CoTaHf, CoFeTi, CoNbHf, CoHfPd, CoTaZrNb, and CoZrMoNi.

Claims

1. An interface region of a magnetic layer to a non-magnetic non-conductive layer,

wherein at least a first part of said interface region includes at least one material selected from the group consisting of CoFeB, CoZrMo, CoZrNb, CoZr, CoZrTa, CoHf, CoTa, CoTaHf, CoFeTi, CoNbHf, CoHfPd, CoTaZrNb, and CoZrMoNi,

wherein at least a second part of said interface region includes an insulation layer disposed against side surfaces of said magnetic layer, said insulation layer being operative to confine a sense current into the magnetic layer to make the magnetic layer operate as a ferromagnetic tunnel junction layer,

wherein at least a third part of said interface region includes a longitudinal bias layer in contact with a side edge of said magnetic layer, said longitudinal bias layer being operative to control magnetic domains of said magnetic layer to within a predetermined region,

wherein said interface region includes a bottom electrode that is in contact with said magnetic layer,

wherein said magnetic layer has a first region in a middle portion of said magnetic layer, a second region forming a first leg of said magnetic layer and disposed at one end of said magnetic layer, and a third region forming a second leg of said magnetic layer and disposed at another end of said magnetic layer, and

wherein said longitudinal bias layer is at least partially disposed between the first leg of said magnetic layer and said bottom electrode.

2. The interface region as claimed in claim 1, wherein a first portion of said insulation layer is disposed directly above said first leg of said magnetic layer so that said first leg is sandwiched between said first portion of said insulation layer and said longitudinal bias layer, and wherein said insulation layer is not disposed directly above said middle portion of said magnetic layer, and

wherein a second portion of said insulation layer is disposed directly above and in contact with said longitudinal bias layer.