Magnetic memory device with increased storage density

Patent metadata

Field	Value
Publication number	US-10490730-B2
Application number	US-201815905915-A
Country	US
Kind code	B2
Filing date	Feb 27, 2018
Priority date	Sep 20, 2017
Publication date	Nov 26, 2019
Grant date	Nov 26, 2019

Abstract

According to one embodiment, a magnetic memory device includes a conductive layer, first and second magnetic layers, a first nonmagnetic layer and a controller. The conductive layer includes first and second portions, and a third portion between the first and second portions. The first magnetic layer is separated from the third portion in a first direction crossing a second direction being from the first portion toward the second portion. The second magnetic layer is provided between the first magnetic layer and at least a portion of the third portion. The first nonmagnetic layer includes first and second regions. The first region is provided between the first and second magnetic layers. The second region is continuous with the first region. The second region overlaps at least a portion of the second magnetic layer in the second direction. The controller is electrically connected to the first and second portions.

First claim

What is claimed is:

1. A magnetic memory device, comprising:
a conductive layer including a first portion, a second portion, and a third portion between the first portion and the second portion, the conductive layer including a first metal;
a first magnetic layer separated from the third portion in a first direction crossing a second direction, the second direction being from the first portion toward the second portion;
a second magnetic layer provided between the first magnetic layer and at least a portion of the third portion;
a first nonmagnetic layer including a first region and a second region, the first region being provided between the first magnetic layer and the second magnetic layer, the second region being continuous with the first region, the second region overlapping at least a portion of the second magnetic layer in the second direction; and
a controller electrically connected to the first portion and the second portion, the controller being configured to supply a current to the conductive layer,
wherein:
the second region includes a first partial region and a second partial region,
a distance along the first direction between the first partial region and the third portion is shorter than a distance along the first direction between the second partial region and the third portion, and
a length along the second direction of the first partial region is shorter than a length along the second direction of the second partial region.

2. The device according to claim 1 , wherein the second region is seamless with the first region.

3. The device according to claim 1 , further comprising a first compound region,
the second magnetic layer including a second metal including at least one selected from the group consisting of Fe, Co, and Ni,
the first compound region including the second metal and at least one selected from the group consisting of oxygen and nitrogen,
at least a portion of the second region being positioned between the first compound region and the at least a portion of the second magnetic layer in the second direction.

4. The device according to claim 1 , further comprising a second compound region,
the conductive layer further including another element including at least one selected from the group consisting of B, Mg, Al, Si, Hf, Ti, and Zr,
the second compound region including at least one selected from the group consisting of oxygen and nitrogen, and at least one selected from the group consisting of the first metal and the other element,
at least a portion of the second region being positioned between the second compound region and the at least a portion of the second magnetic layer in the second direction.

5. The device according to claim 1 , wherein the second region contacts the at least a portion of the second magnetic layer.

6. The device according to claim 1 , wherein
the first region has a first surface opposing the first magnetic layer, and
the first surface is concave.

7. The device according to claim 1 , wherein the second region does not overlap the first magnetic layer in the second direction.

8. The device according to claim 1 , wherein the first metal includes at least one selected from the group consisting of Ta, W, Re, Os, Ir, Pt, Pd, Cu, and Ag.

9. The device according to claim 1 , wherein
the controller implements:
a first program operation of supplying a first program current to the conductive layer from the first portion toward the second portion; and
a second program operation of supplying a second program current to the conductive layer from the second portion toward the first portion,

a first electrical resistance between the first magnetic layer and the first portion after the first program operation being different from a second electrical resistance between the first magnetic layer and the first portion after the second program operation.

10. The device according to claim 1 , wherein a thickness along the second direction of at least a portion of the second region is 0.5 nm or more.

11. A magnetic memory device, comprising:
a conductive layer including a first portion, a second portion, and a third portion between the first portion and the second portion, the conductive layer including a first metal;
a first magnetic layer separated from the third portion in a first direction crossing a second direction, the second direction being from the first portion toward the second portion;
a second magnetic layer provided between the first magnetic layer and at least a portion of the third portion;
a first nonmagnetic layer including a first region and a second region, the first region being provided between the first magnetic layer and the second magnetic layer, the second region being continuous with the first region, the second region overlapping at least a portion of the second magnetic layer in the second direction; and
a controller electrically connected to the first portion and the second portion, the controller being configured to supply a current to the conductive layer, wherein
the first region has a first surface opposing the first magnetic layer,
the first surface includes a first surface portion, a second surface portion, and a third surface portion,
a direction from the first surface portion toward the second surface portion is aligned with the second direction,
a position in the second direction of the third surface portion is between a position in the second direction of the first surface portion and a position in the second direction of the second surface portion, and
a distance along the first direction between the third surface portion and the third portion is shorter than a distance along the first direction between the first surface portion and the third portion.

12. The device according to claim 1 , wherein the first nonmagnetic layer includes at least one selected from the group consisting of Mg and Al, and at least one selected from the group consisting of oxygen and nitrogen.

13. The device according to claim 12 , further comprising a first insulating region,
a direction toward the second magnetic layer from the first insulating region being aligned with a third direction crossing a plane including the first direction and the second direction,
the first insulating region including at least one selected from the group consisting of Si and Al, and at least one selected from the group consisting of oxygen and nitrogen.

14. The device according to claim 13 , further comprising a second insulating region,
a direction from the second insulating region toward at least a portion of the first magnetic layer being aligned with the second direction,
the second insulating region including at least one selected from the group consisting of Si and Al, and at least one selected from the group consisting of oxygen and nitrogen.

15. A magnetic memory device, comprising:
a conductive layer including a first portion, a second portion, and a third portion between the first portion and the second portion, the conductive layer including a first metal;
a first magnetic layer separated from the third portion in a first direction crossing a second direction, the second direction being from the first portion toward the second portion;
a second magnetic layer provided between the first magnetic layer and at least a portion of the third portion;
a first nonmagnetic layer including a first region provided between the first magnetic layer and the second magnetic layer;
a second region overlapping at least a portion of the second magnetic layer in the second direction;
a first insulating region, a direction from the first insu

Assignees

• Toshiba Kk

Inventors

• Shimizu Mariko
• Ohsawa Yuichi
• Sugiyama Hideyuki
• Shirotori Satoshi
• BUYANDALAI Altansargai
• Yoda Hiroaki

Classifications

• G11C11/1673

  Reading or sensing circuits or methods · CPC title

• G11C11/161

  details concerning the memory cell structure, e.g. the layers of the ferromagnetic memory cell · CPC title

• H01L43/08

  Electricity · mapped topic

• H01L43/06

  Electricity · mapped topic

• H01L43/12

  Electricity · mapped topic