Magnetic random access memory having improved reliability through thermal cladding

Patent metadata

Field	Value
Publication number	US-10186308-B1
Application number	US-201815862495-A
Country	US
Kind code	B1
Filing date	Jan 4, 2018
Priority date	Jan 4, 2018
Publication date	Jan 22, 2019
Grant date	Jan 22, 2019

Abstract

A Magnetic Random Access Memory (MRAM) structure having a thermally conductive, dielectric cladding material that contacts an outer side of a magnetic memory element. The magnetic memory element can be a magnetic tunnel junction element formed as a cylindrical pillar that extends between first and second electrically conductive lead layers. The cylinder of the magnetic memory element can have an outer periphery, and the cladding material can be formed to contact the entire periphery. In addition, a heat sink structure formed of a dielectric material having a high specific heat capacity can be formed to contact an outer periphery of the cladding material. The cladding material and heat sink structure efficiently conduct heat away from the sides of the memory element to prevent the temperature of the memory element to rise to unsafe levels. This advantageously assists in maintaining a high reliability and long life of the MRAM system.

First claim

What is claimed is:

1. A magnetic random access memory apparatus, comprising:
a magnetic memory element pillar having first and second ends and an outer side extending between the first and second ends;
first and second electrically conductive leads arranged such that the magnetic memory element pillar is between the first and second electrically conductive leads and each of the ends of the magnetic memory element pillar is electrically connected with one of the first and second electrically conductive leads; and
a cladding material contacting the outer side of the magnetic element pillar, the cladding material being constructed of a material that is both dielectric and has a high thermal conductivity.

2. The magnetic random access memory apparatus as in claim 1 , wherein the cladding material has a thermal conductivity of at least 500 W/m/K.

3. The magnetic random access memory apparatus as in claim 1 , wherein the cladding material has a thermal conductivity of at least 500 W/m/K and has a dielectric constant of at least 4.

4. The magnetic random access memory apparatus as in claim 1 , wherein the cladding material comprises carbon.

5. The magnetic random access memory apparatus as in claim 1 , wherein the cladding material comprises carbon having a cubic crystalline structure.

6. The magnetic random access memory apparatus as in claim 1 , wherein the cladding material comprises carbon formed as diamond like carbon.

7. The magnetic random access memory apparatus as in claim 1 , wherein the cladding material comprises carbon deposited by chemical vapor deposition.

8. The magnetic random access memory apparatus as in claim 1 , wherein the cladding material contacts an entire periphery of the outer side of the magnetic memory element pillar.

9. The magnetic random access memory apparatus as in claim 8 , wherein the cladding material extends from the first electrically conductive lead to the second electrically conductive lead.

10. The magnetic random access memory apparatus as in claim 1 , wherein the magnetic memory element pillar has a generally cylindrical shape having an outer perimeter, and wherein the cladding material contacts an entire perimeter of the cylinder.

11. The magnetic random access memory apparatus as in claim 1 , wherein the magnetic memory element pillar is a magnetic tunnel junction element having a magnetic reference layer, a magnetic free layer and a non-magnetic barrier layer located between the magnetic reference layer and the magnetic free layer.

12. A magnetic random access memory apparatus, comprising:
a magnetic memory element pillar having first and second ends and an outer side extending between the first and second ends;
first and second electrically conductive leads arranged such that the magnetic memory element pillar is between the first and second electrically conductive leads and each of the ends of the magnetic memory element pillar is electrically connected with one of the first and second electrically conductive leads;
a cladding material contacting the outer side of the magnetic element pillar, the cladding material being constructed of a material that is both dielectric and has a high thermal conductivity; and
a heat sink material contacting the cladding material, the heat sink material being constructed of a material that is both dielectric and has a specific high heat capacity.

13. The magnetic random access memory apparatus as in claim 12 , wherein the heat sink material has a specific heat capacity of at least 500 J/kg/K.

14. The magnetic random access memory apparatus as in claim 12 , wherein the heat sink material has a specific heat capacity of at least 500 J/kg/K and has a dielectric constant of at least 4.

15. The magnetic random access memory apparatus as in claim 12 , wherein the heat sink material comprises AN.

16. The magnetic random access memory apparatus as in claim 12 , wherein the heat sink material comprises alumina.

17. The magnetic random access memory apparatus as in claim 12 , wherein the heat sink material is located between the first and second electrically conductive leads and surrounds the cladding material.

18. The magnetic random access memory apparatus as in claim 12 , wherein the cladding material has an outer periphery, and wherein the heat sink material contacts the entire outer periphery of the cladding material, while also contacting the first and second electrically conductive leads.

19. The magnetic random access memory apparatus as in claim 12 , wherein the magnetic element pillar is formed as a cylinder having an outer periphery, and wherein the cladding material contacts the outer periphery of the cylinder.

20. The magnetic random access memory apparatus as in claim 12 , wherein the magnetic memory element is a magnetic tunnel junction having a magnetic reference layer, a magnetic free layer and a non-magnetic barrier layer located between the magnetic reference layer and the magnetic free layer.

Assignees

• Spin Transfer Tech Inc

Inventors

• Guarisco Davide
• Ryan Eric Michael
• Gajek Marcin
• Jagtiani Girish

Classifications

• G11C11/15

  using multiple magnetic layers (G11C11/155 takes precedence) · CPC title

• G11C11/1675

  Writing or programming circuits or methods · CPC title

• G11C11/1673

  Reading or sensing circuits or methods · 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