Magnetic device with gate electrode

Patent metadata

Field	Value
Publication number	US-11730065-B2
Application number	US-202117359822-A
Country	US
Kind code	B2
Filing date	Jun 28, 2021
Priority date	Nov 6, 2020
Publication date	Aug 15, 2023
Grant date	Aug 15, 2023

Abstract

Provided is a magnetic device including a conductive layer extended in a first direction and providing a spin Hall effect on a placement plane defined by the first direction and a second direction, a free layer disposed on the conductive layer, a fixed layer disposed on a portion of the free layer, a tunnel barrier layer disposed between the free layer and the fixed layer, a first electrode disposed on the fixed layer, a first charge storage layer disposed on the free layer so as not to overlap the fixed layer, and a first gate electrode disposed on the first charge storage layer. The first electrode and the first gate electrode are arranged in the second direction.

First claim

What is claimed is:

1. A magnetic device comprising:
a conductive layer extended in a first direction and providing a spin Hall effect on a placement plane defined by the first direction and a second direction;
a free layer disposed on the conductive layer;
a fixed layer disposed on a portion of the free layer;
a tunnel barrier layer disposed between the free layer and the fixed layer;
a first electrode disposed on the fixed layer;
a first charge storage layer disposed on the free layer so as not to overlap the fixed layer; and
a first gate electrode disposed on the first charge storage layer,
wherein the first electrode and the first gate electrode are arranged in the second direction.

2. The magnetic device of claim 1 , wherein:
the first charge storage layer is an oxide film; and
oxygen ions of the first charge storage layer generate a lateral modulation of the Rashba effect or an out-of-plane spin orbit torque by a voltage applied to the first gate electrode.

3. The magnetic device of claim 1 , wherein:
the first charge storage layer comprises fixed charges; and
a voltage applied to the first gate electrode moves the fixed charges of the first charge storage layer.

4. The magnetic device of claim 1 , wherein:
the first charge storage layer comprises trapped charges; and
charges are trapped in the first charge storage layer by a voltage applied to the first gate electrode.

5. The magnetic device of claim 1 , further comprising an auxiliary tunnel barrier layer disposed between the first charge storage layer and the free layer.

6. The magnetic device of claim 1 , wherein the tunnel barrier layer is extended to overlap the first charge storage layer.

7. The magnetic device of claim 1 , wherein the first charge storage layer comprises a tunnel insulation layer, a floating conductive layer, and a blocking insulation layer sequentially stacked.

8. The magnetic device of claim 1 , wherein the first charge storage layer comprises a tunnel insulation layer, a charge trapping layer, and a blocking insulation layer sequentially stacked.

9. The magnetic device of claim 1 , further comprising:
a second charge storage layer disposed on the free layer so as not to overlap the fixed layer and the first charge storage layer; and
a second gate electrode disposed on the second charge storage layer,
wherein the first gate electrode, the first electrode, and the second gate electrode are sequentially arranged in the second direction.

10. The magnetic device of claim 9 , wherein the first charge storage layer and the second charge storage layer comprise a tunnel insulation layer, a charge trapping layer, and a blocking insulation layer sequentially stacked.

11. The magnetic device of claim 9 , wherein the first charge storage layer and the second charge storage layer comprise fixed charges.

12. A method for operating a magnetic device including a conductive layer extended in a first direction and providing a spin Hall effect on a placement plane defined by the first direction and a second direction, a free layer disposed on the conductive layer, a fixed layer disposed on a portion of the free layer, a tunnel barrier layer disposed between the free layer and the fixed layer, a first electrode disposed on the fixed layer, a first charge storage layer disposed on the free layer so as not to overlap the fixed layer, and a first gate electrode disposed on the first charge storage layer, wherein the first electrode and the first gate electrode are arranged in the second direction, the method comprising:
applying a first program gate voltage to the first gate electrode to accumulate charges in or move the charges to the first charge storage layer, thereby programming the first charge storage layer to a first program state;
applying an in-plane current to the conductive layer to switch a magnetization direction of the free layer; and
applying a read voltage to the first electrode to read tunnel resistance of a magnetic tunnel junction by the free layer/tunnel barrier layer/fixed layer.

13. The method of claim 12 , further comprising at least one among:
applying an erase gate voltage having an opposite polarity to the first program gate voltage to the first gate electrode to remove the first program state formed in the first charge storage layer;
when the first charge storage layer is in an erase state, applying a second program gate voltage to the first gate electrode to accumulate charges in or move the charges to the first charge storage layer, thereby programming the first charge storage layer to a second program state;
applying an in-plane current I_inplane to the conductive layer to switch the magnetization direction of the free layer; and
applying an erase gate voltage having an opposite polarity to the second program gate voltage to the first gate electrode to remove the second program state formed in the first charge storage layer.

14. A method for operating a magnetic device including a conductive layer extended in a first direction and providing a spin Hall effect on a placement plane defined by the first direction and a second direction, a free layer disposed on the conductive layer, a fixed layer disposed on a portion of the free layer, a tunnel barrier layer disposed between the free layer and the fixed layer, a first electrode disposed on the fixed layer, a first charge storage layer disposed on the free layer so as not to overlap the fixed layer, a first gate electrode disposed on the first charge storage layer, a second charge storage layer disposed on the free layer so as not to overlap the fixed layer and the first charge storage layer; and a second gate electrode disposed on the second charge storage layer, wherein the first gate electrode, the first electrode, and the second gate electrode are sequentially arranged in the second direction, the method comprising:
applying a first program gate voltage to the first gate electrode to accumulate charges in or move the charges to the first charge storage layer, thereby programming the first charge storage layer to a first program state;
applying an in-plane current to the conductive layer to switch the magnetization direction of the free layer; and
applying a read voltage to the first electrode to read tunnel resistance of a magnetic tunnel junction by the free layer/tunnel barrier layer/fixed layer.

15. The method of claim 14 , further comprising applying an erase gate voltage having an opposite polarity to the first program gate voltage to the first gate electrode to remove the first program state formed in the first charge storage layer.

Assignees

• Korea Advanced Inst Sci & Tech

Inventors

• Park Byong Guk
• Kang Min-Gu
• Choi Jong-Guk

Classifications

• H10N52/80 Primary

  Constructional details · CPC title

• G11C11/161 Primary

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

• G11C11/1673

  Reading or sensing circuits or methods · CPC title

• G11C11/1675

  Writing or programming circuits or methods · CPC title

• G11C11/18

  using Hall-effect devices · CPC title