Metallic magnetic memory devices for cryogenic operation and methods of operating the same

Patent metadata

Field	Value
Publication number	US-10916284-B2
Application number	US-202016902641-A
Country	US
Kind code	B2
Filing date	Jun 16, 2020
Priority date	Dec 6, 2018
Publication date	Feb 9, 2021
Grant date	Feb 9, 2021

Abstract

A MRAM device includes a spin valve containing a reference layer having a fixed magnetization direction, a free layer, and a nonmagnetic metallic barrier layer located between the reference layer and the free layer, a metallic assist structure configured to provide rotating spin transfer torque to the free layer to assist the free layer switching during programming, and a first nonmagnetic metallic spacer layer located between the free layer and the metallic assist structure.

First claim

What is claimed is:

1. A MRAM device, comprising:
a spin valve comprising a reference layer having a fixed magnetization direction, a free layer, and a nonmagnetic metallic barrier layer located between the reference layer and the free layer;
a metallic assist structure configured to provide rotating spin transfer torque to the free layer to assist the free layer switching during programming; and
a first nonmagnetic metallic spacer layer located between the free layer and the metallic assist structure;
wherein the metallic assist structure comprises a negative-magnetic-anisotropy assist layer which comprises a multilayer stack including multiple repetitions of a first magnetic material layer and a second magnetic material layer.

2. The MRAM device of claim 1 , wherein:
the first magnetic material layer comprises cobalt; and
the second magnetic material layer comprises iron.

3. The MRAM cell of claim 1 , wherein the metallic assist structure comprises a spin torque oscillator stack.

4. The MRAM cell of claim 1 , wherein the nonmagnetic metallic barrier layer comprises a material selected from Cu, Ag, AgSn, Cr, Ge, Ta, TaN, or CuN.

5. The MRAM cell of claim 1 , wherein the MRAM cell does not contain any electrically insulating layers, and the MRAM cell is configured to be operated at a temperature below 77 degrees Kelvin.

Assignees

• Sandisk Technologies Llc

Inventors

• Le Quang
• Li Zhanjie
• Bai Zhigang
• Vanderheijden Paul
• Ho Michael

Classifications

• H10N50/85

  Materials of the active region · CPC title

• G11C11/1659

  Cell access · CPC title

• G11C11/161 Primary

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

• G11C11/18

  using Hall-effect devices · CPC title

• G11C11/1675 Primary

  Writing or programming circuits or methods · CPC title