Magnetic memory device

Patent metadata

Field	Value
Publication number	US-10529399-B2
Application number	US-201816106694-A
Country	US
Kind code	B2
Filing date	Aug 21, 2018
Priority date	Mar 7, 2018
Publication date	Jan 7, 2020
Grant date	Jan 7, 2020

Abstract

According to one embodiment, a magnetic memory device includes a conductive layer, a first magnetic layer, a second magnetic layer, and a first nonmagnetic layer. The conductive layer includes a first region, a second region, and a third region between the first region and the second region. The second magnetic layer is provided between the third region and the first magnetic layer in a first direction crossing a second direction. The second direction is from the first region toward the second region. The first nonmagnetic layer is provided between the first magnetic layer and the second magnetic layer. The third region includes first and second end portions. The first end portion includes a first protrusion. The second end portion includes a second protrusion. A first position along the second direction of the first protrusion is different from a second position along the second direction of the second protrusion.

First claim

What is claimed is:

1. A magnetic memory device, comprising:
a conductive layer including a first region, a second region, and a third region between the first region and the second region;
a first magnetic layer;
a second magnetic layer provided between the third region and the first magnetic layer in a first direction crossing a second direction, the second direction being from the first region toward the second region; and
a first nonmagnetic layer provided between the first magnetic layer and the second magnetic layer,
the third region including a first end portion and a second end portion, a direction from the second end portion toward the first end portion crossing a first plane, the first plane including the first direction and the second direction,
the first end portion including a first protrusion,
the second end portion including a second protrusion,
a first position along the second direction of the first protrusion being different from a second position along the second direction of the second protrusion.

2. The device according to claim 1 , wherein a length of the second magnetic layer along a top portion direction is different from a length of the second magnetic layer along the second direction, the top portion direction being from a top portion of the second protrusion toward a top portion of the first protrusion.

3. The device according to claim 1 , wherein a portion of the second magnetic layer is along at least a portion of the first protrusion.

4. The device according to claim 1 , wherein
the third region includes a region overlapping the second magnetic layer in the first direction, and
a thickness along the first direction of the overlapping region is thicker than a thickness along the first direction of the first region and thicker than a thickness along the first direction of the second region.

5. The device according to claim 1 , wherein the conductive layer includes at least one selected from the group consisting of tantalum and tungsten.

6. The device according to claim 1 , further comprising a controller electrically connected to the first region and the second region,
the controller being configured to perform at least a first operation of supplying a first current to the conductive layer from the first region toward the second region, and a second operation of supplying a second current to the conductive layer from the second region toward the first region.

7. The device according to claim 6 , wherein
the controller is further electrically connected to the first magnetic layer,
the controller sets a first potential difference between the first region and the first magnetic layer to a first voltage in the first operation,
the controller sets the first potential difference to the first voltage in the second operation,
the controller further performs a third operation and a fourth operation,
in the third operation, the controller sets the first potential difference between the first region and the first magnetic layer to a second voltage and supplies the first current to the conductive layer, the second voltage being different from the first voltage,
in the fourth operation, the controller sets the first potential difference to the second voltage and supplies the second current to the conductive layer,
a first electrical resistance between the first magnetic layer and the conductive layer after the first operation is different from a second electrical resistance between the first magnetic layer and the conductive layer after the second operation, and
an absolute value of a difference between the first electrical resistance and the second electrical resistance is greater than an absolute value of a difference between an electrical resistance between the first magnetic layer and the conductive layer after the third operation and an electrical resistance between the first magnetic layer and the conductive layer after the fourth operation.

8. The device according to claim 1 , further comprising
a third magnetic layer;
a fourth magnetic layer;
a second nonmagnetic layer; and
a controller,
the conductive layer further including a fourth region and a fifth region, the second region being provided between the first region and the fourth region in the second direction, the fifth region being provided between the second region and the fourth region in the second direction,
the fourth magnetic layer being provided between the fifth region and the third magnetic layer in the first direction,
the second nonmagnetic layer being provided between the third magnetic layer and the fourth magnetic layer,
the controller being electrically connected to the first region, the second region and the fourth region,
the controller being configured to perform at least a first program operation of supplying a first current to the conductive layer and supplying a second current to the conductive layer, the first current having a direction from the first region toward the second region, the second current having a direction from the fourth region toward the second region.

9. The device according to claim 8 , wherein
the controller is configured to further perform at least a second program operation of supplying a third current to the conductive layer and supplying a fourth current to the conductive layer, the third current having a direction from the second region toward the first region, the fourth current having a direction from the second region toward the fourth region.

10. The device according to claim 9 , wherein
the controller is further connected to the first magnetic layer and the third magnetic layer,
the controller is configured to further perform at least a read operation of applying a voltage between the first magnetic layer and the third magnetic layer, and detecting a potential of the second region.

Assignees

• Toshiba Kk

Inventors

• Ohsawa Yuichi
• Shimizu Mariko
• Shirotori Satoshi
• Sugiyama Hideyuki
• BUYANDALAI Altansargai
• Yoda Hiroaki
• Koui Katsuhiko
• Inokuchi Tomoaki
• Shimomura Naoharu

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

• G11C11/1659

  Cell access · CPC title

• G11C11/1675 Primary

  Writing or programming circuits or methods · CPC title

• H01L43/08

  Electricity · mapped topic