Magnetic tunnel junction device and method of making same

• US 9,231,191 B2
• Filed: 05/23/2013
• Issued: 01/05/2016
• Est. Priority Date: 08/20/2012
• Status: Active Grant

• Current Assignee: Industrial Technology Research Institute
• Original Assignee: Industrial Technology Research Institute
• Inventors: Huang, Sheng-Huang, Shen, Kuei-Hung, Wang, Yung-Hung
• Primary Examiner(s): BERNATZ, KEVIN M
• Application Number:
  US13/901,412
• Publication Number:
  US 20140048896A1
• Time in Patent Office: 957 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: G01R 33/091 Constructional adaptation of the sensor to specific applications
• CPC Class Codes: G01R 33/098 comprising tunnel junctions, e.g. tunnel magnetoresistance sensors
• CPC Class Codes: G11B 5/3909 Arrangements using a magnetic tunnel junction
• CPC Class Codes: G11C 11/15 using multiple magnetic layers G11C11/155 takes precedence
• CPC Class Codes: H10N 50/01 Manufacture or treatment
• CPC Class Codes: H10N 50/10 Magnetoresistive devices
• CPC Class Codes: H10N 50/80 Constructional details

Abstract

A magnetic tunnel junction (MTJ) device includes a reference layer having a surface, a tunnel insulating layer formed over the surface of the reference layer, a free layer formed over the tunnel insulating layer, and a magnetic field providing layer formed over the free layer. A magnetization direction in each of the reference layer and the free layer is substantially perpendicular to the surface. The magnetic field providing layer is configured to provide a lateral magnetic field in the free layer, the lateral magnetic field being substantially parallel to the surface.

Claims

1. A magnetic tunnel junction (MTJ) device, comprising:

a reference layer having a surface;

a tunnel insulating layer formed over the surface of the reference layer;

a free layer formed over the tunnel insulating layer, a magnetization direction in each of the reference layer and the free layer being substantially perpendicular to the surface; and

a magnetic field providing layer formed over the free layer, configured to provide a lateral magnetic field in the free layer, the lateral magnetic field being substantially parallel to the surface, and the magnetic field providing layer including;

an isolation spacer layer formed over the free layer;

a ferromagnetic layer formed over the isolation spacer layer, a magnetization direction in the ferromagnetic layer being substantially parallel to the surface; and

an antiferromagnetic layer formed between the isolation spacer layer and the ferromagnetic layer.

2. The MTJ device of claim 1, wherein:

the reference layer includes one of a CoFeB single-layer film, a Co/Pt multilayer film, a Co/Pd multilayer film, a Co/Ni multilayer film, a CoPd alloy, or a FePt alloy, or a laminated layer including any combination thereof, and

the free layer includes one of a CoFeB single-layer film, a Co/Pt multilayer film, a Co/Pd multilayer film, a Co/Ni multilayer film, a CoPd alloy, or a FePt alloy, or a laminated layer including any combination thereof.

3. The MTJ device of claim 1, wherein the ferromagnetic layer includes one of a single-layer film including CoFeB, NiFe, CoFe, Co, Fe, or Ni, a Co/Pt multilayer film, a Co/Pd multilayer film, a Co/Ni multilayer film, a CoPd alloy, or a FePt alloy, or a laminated layer including any combination thereof.

4. The MTJ device of claim 1, wherein the antiferromagnetic layer includes one of PtMn or IrMn.

5. The MTJ device of claim 1, wherein:

the isolation spacer layer is a first isolation spacer layer,

the ferromagnetic layer is a first ferromagnetic layer, and

the magnetic field providing layer further comprises;

a second isolation spacer layer formed over the first ferromagnetic layer; and

a second ferromagnetic layer formed over the second isolation spacer layer.

6. The MTJ device of claim 1, wherein a dimension of the reference layer in a horizontal direction substantially parallel to the surface is larger than a dimension of the free layer in the horizontal direction.

7. The MTJ device of claim 1, further comprising:

a spacer layer formed below the reference layer; and

a lower reference layer formed below the spacer layer, a magnetization direction in the lower reference layer being substantially perpendicular to the surface and substantially opposite to the magnetization direction in the reference layer.

8. The MTJ device of claim 1, further comprising:

a hard mask capping layer formed over the magnetic field providing layer.