Magnetoresistive effect element, and magnetic random access memory

• US 8,908,423 B2
• Filed: 11/22/2010
• Issued: 12/09/2014
• Est. Priority Date: 11/27/2009
• Status: Active Grant

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Honjou, Hiroaki
• Primary Examiner(s): Bryne, Harry W
• Application Number:
  US13/512,215
• Publication Number:
  US 20120281463A1
• Time in Patent Office: 1,478 Days
• Field of Search: 365/8, 365/55, 365/62, 365/66, 365/74, 365/78, 365 80- 93, 365/100, 365/130, 365/131, 365/148, 365/158, 365171-173, 365/209, 365/213, 365/225.5, 365/230.07, 365/232, 365/243.5, 257/295, 257/421, 257/422, 257/427, 257/E21.665, 257/E27.006, 438/3, 977933-935
• US Class Current: 365/158
• CPC Class Codes: G11C 11/16 using elements in which the storage effect is based on magnetic spin effect
• CPC Class Codes: G11C 11/161 details concerning the memory cell structure, e.g. the layers of the ferromagnetic memory cell
• CPC Class Codes: G11C 11/1655 Bit-line or column circuits
• CPC Class Codes: G11C 11/1659 Cell access
• CPC Class Codes: G11C 11/1673 Reading or sensing circuits or methods
• CPC Class Codes: G11C 11/1675 Writing or programming circuits or methods
• CPC Class Codes: H10B 61/22 of the field-effect transistor [FET] type
• CPC Class Codes: H10N 50/10 Magnetoresistive devices
• CPC Class Codes: Y10S 977/933 Spintronics or quantum computing
• CPC Class Codes: Y10S 977/935 Spin dependent tunnel, SDT, junction, e.g. tunneling magnetoresistance, TMR

Abstract

A magnetoresistive effect element includes: a

• • magnetization free layer having an invertible magnetization; an insulating layer being adjacent to the magnetization free layer; and a magnetization fixed layer being adjacent to the insulation layer and in an opposite side of the insulation layer to the magnetization free layer.

The magnetization free layer includes: a first magnetization free layer being adjacent to the insulating layer and comprising Fe or Co; and a second magnetization free layer being adjacent to the first magnetization layer

• • and comprising NiFeB.

Claims

1. A magnetoresistive effect element comprising:

a magnetization free layer having an invertible magnetization;

an insulating layer being adjacent to the magnetization free layer; and

a magnetization fixed layer being adjacent to the insulation layer and in an opposite side of the insulation layer to the magnetization free layer,

wherein the magnetization free layer comprises;

a first magnetization free layer being adjacent to the insulating layer and comprising Fe or Co; and

a second magnetization free layer being adjacent to the first magnetization layer and comprising NiFeB,

wherein a composition of the second magnetization free layer is as follows

Ni;

equal to or more than 70% and equal to or less than 90%,

Fe;

equal to or more than 5% and equal to or less than 15%,

B;

equal to or more than 5% and equal to or less than 20%.

2. The magnetoresistive effect element according to claim 1, wherein a thickness of the first magnetization free layer is equal to or more than 0.1 nm and equal to or less than 1.0 nm.

3. The magnetoresistive effect element according to claim 2, wherein a thickness of the second magnetization free layer is equal to or more than 3 nm and equal to or less than 20 nm.

4. The magnetoresistive effect element according to claim 1, wherein the insulating layer comprises MgO.

5. The magnetoresistive effect element according to claim 1, wherein a magnetization of the magnetization free layer is configured to be inverted by a magnetic field induced by a current flowing an interconnection layer arranged near the magnetization free layer.

6. A magnetic random access memory comprising:

a plurality of magnetic memory cell arranged to form an array; and

a control circuit configured to control writing and reading operations of the plurality of magnetic memory cell,

wherein each of the plurality of magnetic memory cells comprises;

the magnetoresistive effect element according to claim 1; and

an interconnection layer arranged near the magnetoresistive element and a write current flows therein.