Magnetic memory incorporating dual selectors

• US 10,522,590 B2
• Filed: 03/14/2018
• Issued: 12/31/2019
• Est. Priority Date: 03/14/2018
• Status: Active Grant

• Current Assignee: Avalanche Technology Incorporated
• Original Assignee: Avalanche Technology Incorporated
• Inventors: Satoh, Kimihiro, Yang, Hongxin
• Primary Examiner(s): Erdem, Fazli
• Application Number:
  US15/921,552
• Publication Number:
  US 20190288031A1
• Time in Patent Office: 657 Days
• Field of Search: 257421
• 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 11/1659 Cell access
• CPC Class Codes: G11C 11/1675 Writing or programming circuits or methods
• CPC Class Codes: H01F 10/3268 the exchange coupling being asymmetric, e.g. by use of additional pinning, by using antiferromagnetic or ferromagnetic coupling interface, i.e. so-called spin-valve [SV] structure, e.g. NiFe/Cu/NiFe/FeMn
• CPC Class Codes: H01F 10/3272 by use of anti-parallel coupled [APC] ferromagnetic layers, e.g. artificial ferrimagnets [AFI], artificial [AAF] or synthetic [SAF] anti-ferromagnets
• CPC Class Codes: H10B 61/00 Magnetic memory devices, e.g. magnetoresistive RAM [MRAM] devices
• CPC Class Codes: H10B 61/10 comprising components having two electrodes, e.g. diodes or MIM elements
• CPC Class Codes: H10N 50/10 Magnetoresistive devices
• CPC Class Codes: H10N 50/80 Constructional details
• CPC Class Codes: H10N 50/85 Magnetic active materials

Abstract

The present invention is directed to a memory device including a magnetic memory element; a horizontal conductive line disposed above the magnetic memory element; a bottom electrode formed beneath the magnetic memory element and having a top, first and second sides that are opposite to each other; a first vertical conductive line formed adjacent to the first side of the bottom electrode with a first volatile switching layer and a first electrode layer interposed therebetween; and a second vertical conductive line formed adjacent to the second side of the bottom electrode with a second volatile switching layer and a second electrode layer interposed therebetween. The magnetic memory element is electrically connected to the horizontal conductive line at one end and to the bottom electrode at the other end.

Claims

1. A memory device comprising:

a magnetic memory element;

a horizontal conductive line disposed above said magnetic memory element;

a bottom electrode formed beneath said magnetic memory element, said bottom electrode having a top, first and second sides that are opposite to each other;

a first vertical conductive line electrically connected to said first side of said bottom electrode with a first volatile switching layer and a first electrode layer interposed therebetween; and

a second vertical conductive line electrically connected to said second side of said bottom electrode with a second volatile switching layer and a second electrode layer interposed therebetween,

wherein said magnetic memory element is electrically connected to said horizontal conductive line at one end and to said bottom electrode at the other end.

2. The memory device of claim 1, wherein said first side of said bottom electrode, said first volatile switching layer, and said first electrode layer collectively form a first selector element electrically connected to said magnetic memory element.

3. The memory device of claim 1, wherein said second side of said bottom electrode, said second volatile switching layer, and said second electrode layer collectively form a second selector element electrically connected to said magnetic memory element.

4. The memory device of claim 1, wherein said first and second volatile switching layers are made of different materials.

5. The memory device of claim 1, wherein said first and second volatile switching layers are made of a same material.

6. The memory device of claim 1 further comprising one or more electrode layers formed between said first volatile switching layer and said first side of said bottom electrode.

7. The memory device of claim 1 further comprising one or more electrode layers formed between said first volatile switching layer and said first vertical conductive line.

8. The memory device of claim 1 further comprising one or more electrode layers formed between said second volatile switching layer and said second side of said bottom electrode.

9. The memory device of claim 1 further comprising one or more electrode layers formed between said second volatile switching layer and said second vertical conductive line.

10. The memory device of claim 1, wherein said magnetic memory element includes a magnetic free layer structure and a magnetic reference layer structure with an insulating tunnel junction layer interposed therebetween, said magnetic fixed layer having a first invariable magnetization direction substantially perpendicular to a layer plane thereof, said magnetic free layer structure having a variable magnetization direction substantially perpendicular to a layer plane thereof.

11. The memory device of claim 10, wherein said magnetic free layer structure is in contiguous contact with said bottom electrode.

12. A memory device comprising:

a magnetic memory element including a magnetic free layer structure and a magnetic reference layer structure with an insulating tunnel junction layer interposed therebetween, said magnetic fixed layer having a first invariable magnetization direction substantially perpendicular to a layer plane thereof, said magnetic free layer structure having a variable magnetization direction substantially perpendicular to a layer plane thereof;

a horizontal conductive line disposed above said magnetic memory element;

a bottom electrode formed beneath said magnetic memory element, said bottom electrode having a top, first and second sides that are opposite to each other;

a first vertical conductive line electrically connected to said first side of said bottom electrode with a first volatile switching layer and a first electrode layer interposed therebetween; and

a second vertical conductive line electrically connected to said second side of said bottom electrode with a second volatile switching layer and a second electrode layer interposed therebetween,

wherein said magnetic memory element is electrically connected to said horizontal conductive line at one end and to said bottom electrode at the other end,

wherein said magnetic memory element further includes a magnetic fixed layer structure separated from said magnetic reference layer by an anti-ferromagnetic coupling layer, said magnetic fixed layer structure having a second invariable magnetization direction that is substantially perpendicular to a layer plane thereof and is opposite to said first invariable magnetization direction.

13. A memory device comprising:

a magnetic memory element including a magnetic free layer structure and a magnetic reference layer structure with an insulating tunnel junction layer interposed therebetween, said magnetic fixed layer having a first invariable magnetization direction substantially perpendicular to a layer plane thereof, said magnetic free layer structure having a variable magnetization direction substantially perpendicular to a layer plane thereof;

a horizontal conductive line disposed above said magnetic memory element;

a bottom electrode formed beneath said magnetic memory element, said bottom electrode having a top, first and second sides that are opposite to each other;

a first vertical conductive line electrically connected to said first side of said bottom electrode with a first volatile switching layer and a first electrode layer interposed therebetween; and

a second vertical conductive line electrically connected to said second side of said bottom electrode with a second volatile switching layer and a second electrode layer interposed therebetween,

wherein said magnetic memory element is electrically connected to said horizontal conductive line at one end and to said bottom electrode at the other end,

wherein said magnetic memory element further includes a magnetic fixed layer structure separated from said magnetic reference layer by an anti-ferromagnetic coupling layer comprising iridium, said magnetic fixed layer structure having a second invariable magnetization direction that is substantially perpendicular to a layer plane thereof and is opposite to said first invariable magnetization direction.