MAGNETIC MEMORY INCLUDING MEMORY CELLS INCORPORATING DATA RECORDING LAYER WITH PERPENDICULAR MAGNETIC ANISOTROPY FILM

• US 20120135275A1
• Filed: 11/23/2011
• Published: 05/31/2012
• Est. Priority Date: 11/26/2010
• Status: Active Grant

• Current Assignee: Renesas Electronics Corporation
• Original Assignee: Renesas Electronics Corporation
• Inventors: Tanigawa, Hironobu, Nagahara, Kiyokazu, Ozaki, Yasuaki, Kariyada, Eiji, Suemitsu, Katsumi, Mori, Kaoru, Suzuki, Tetsuhiro, Ohshima, Norikazu
• Granted Patent: US 8,830,735 B2
• Time in Patent Office: Days
• US Class Current: 428/828.1
• CPC Class Codes: G01R 33/091 Constructional adaptation of the sensor to specific applications
• CPC Class Codes: G01R 33/098 comprising tunnel junctions, e.g. tunnel magnetoresistance sensors
• CPC Class Codes: G11C 11/02 using magnetic elements
• CPC Class Codes: G11C 11/14 using thin-film elements
• CPC Class Codes: G11C 11/15 using multiple magnetic layers G11C11/155 takes precedence
• CPC Class Codes: G11C 11/161 details concerning the memory cell structure, e.g. the layers of the ferromagnetic memory cell
• CPC Class Codes: H10N 50/85 Magnetic active materials
• CPC Class Codes: Y10T 428/1114 having tunnel junction effect
• CPC Class Codes: Y10T 428/1121 Multilayer
• CPC Class Codes: Y10T 428/1143 with defined structural feature

Abstract

A magnetic memory includes: a magnetization fixed layer having perpendicular magnetic anisotropy, a magnetization direction of the magnetization fixed layer being fixed; an interlayer dielectric; an underlayer formed on upper faces of the magnetization fixed layer and the interlayer dielectric; and a data recording layer formed on an upper face of the underlayer and having perpendicular magnetic anisotropy. The underlayer includes: a first magnetic underlayer; and a non-magnetic underlayer formed on the first magnetic underlayer. The first magnetic underlayer is formed with such a thickness that the first magnetic underlayer does not exhibit in-plane magnetic anisotropy in a portion of the first magnetic underlayer formed on the interlayer dielectric.

Claims

1. A magnetic memory, comprising:

a magnetization fixed layer having perpendicular magnetic anisotropy, a magnetization direction of said magnetization fixed layer being fixed;

an interlayer dielectric;

an underlayer formed on upper faces of said magnetization fixed layer and said interlayer dielectric; and

a data recording layer formed on an upper face of said underlayer and having perpendicular magnetic anisotropy,

wherein said underlayer includes;

a first magnetic underlayer; and

a non-magnetic underlayer formed on said first magnetic underlayer, and

wherein said first magnetic underlayer is formed with such a thickness that said first magnetic underlayer does not exhibit in-plane magnetic anisotropy in a portion of said first magnetic underlayer formed on said interlayer dielectric.

2. The magnetic memory according to claim 1, wherein the thickness of said first magnetic underlayer is adjusted so that said first magnetic underlayer does not exhibit ferromagnetism in the portion of said first magnetic underlayer formed on said interlayer dielectric.

3. The magnetic memory according to claim 2, wherein said first magnetic underlayer includes NiFe as a major constituent and includes at least one non-magnetic element selected from the group consisting of Zr, Ta, W, Hf and V.

4. The magnetic memory according to claim 3, wherein said first magnetic underlayer has a thickness in a range from 0.5 to 3 nm.

5. The magnetic memory according to claim 4, wherein the thickness of said first magnetic underlayer is less than 2 nm.

6. The magnetic memory according to claim 3, wherein a concentration of said at least one non-magnetic element in said first magnetic underlayer is in a range from 10 to 25 atomic %.

10. The magnetic memory according to claim 1, wherein said first magnetic underlayer is formed of magnetic material which intrinsically exhibits in-plane magnetic anisotropy, with such a thickness that a portion of said first magnetic underlayer disposed on said interlayer dielectric exhibits perpendicular magnetic anisotropy.

11. The magnetic memory according to claim 10, wherein said first magnetic underlayer includes Co or Fe as a major constituent and includes at least one non-magnetic element selected from the group consisting of Zr, Ta, W, Hf and V.

12. The magnetic memory according to claim 11, wherein a thickness of said first magnetic underlayer is in a range from 0.5 to 3 nm.

14. The magnetic memory according to claim 1, further comprising a second magnetic underlayer disposed between said non-magnetic underlayer and said data recording layer,

wherein said second magnetic underlayer includes at least one film stack including a layer of Pt or Pd and a layer of Fe, Co or Ni.

15. The magnetic memory according to claim 1, wherein said non-magnetic underlayer is formed of material selected from the group consisting of Pt, Au, Pd and Ir.

16. The magnetic memory according to claim 15, wherein a thickness of said non-magnetic underlayer is equal to or more than 0.5 nm and less than 3.0 nm.

17. The magnetic memory according to claim 1, wherein said non-magnetic underlayer is formed of a Ta film having a thickness of 0.1 to 2.0 nm.

7. A magnetic memory, comprising:

a magnetization fixed layer having perpendicular magnetic anisotropy, a magnetization direction of said magnetization fixed layer being fixed;

an interlayer dielectric;

an underlayer formed on upper faces of said magnetization fixed layer and said interlayer dielectric; and

a data recording layer formed on an upper face of said underlayer and having perpendicular magnetic anisotropy,

wherein said underlayer includes;

a first magnetic underlayer; and

a non-magnetic underlayer formed on said first magnetic underlayer, and

wherein said first magnetic underlayer includes NiFe as major constitution and includes at least one non-magnetic element selected from the group consisting of Zr, Ta, W, Hf and V, and

wherein a thickness of said first magnetic underlayer is in a range from 0.5 to 3 nm.

8. The magnetic memory according to claim 7, wherein the thickness of said first magnetic underlayer is less than 2 nm.

9. The magnetic memory according to claim 7, wherein a concentration of said at least one non-magnetic element in said first magnetic underlayer is in a range from 10 to 25 atomic %.

13. A magnetic memory, comprising:

a magnetization fixed layer having perpendicular magnetic anisotropy, a magnetization direction of said magnetization fixed layer being fixed;

an interlayer dielectric;

an underlayer formed on upper faces of said magnetization fixed layer and said interlayer dielectric; and

a data recording layer formed on an upper face of said underlayer and having perpendicular magnetic anisotropy,

wherein said underlayer includes;

a first magnetic underlayer; and

a non-magnetic underlayer formed on said first magnetic underlayer, and

wherein said first magnetic underlayer includes Co or Fe as major constitution and includes at least one non-magnetic element selected from the group consisting of Zr, Ta, W, Hf and V, and

wherein a thickness of said first magnetic underlayer is in a range from 0.5 to 3 nm.

18. A magnetic memory, comprising:

a ferromagnetic underlayer formed of magnetic material;

a non-magnetic intermediate layer disposed on said underlayer;

a ferromagnetic data recording layer formed on said intermediate layer and having perpendicular magnetic anisotropy;

a reference layer connected to said across a non-magnetic layer; and

first and second magnetization fixed layers disposed in contact with a bottom face of said underlayer,

wherein said data recording layer includes;

a magnetization free region having a reversible magnetization and opposed to said reference layer;

a first magnetization fixed region coupled to a first border of said magnetization free layer and having a magnetization fixed in a first direction; and

a second magnetization fixed region coupled to a second border of said magnetization free layer and having a magnetization fixed in a second direction opposite to said first direction;

wherein said intermediate layer is formed of a Ta film having a thickness of 0.1 to 2.0 nm.

19. The magnetic memory according to claim 18, wherein said underlayer is amorphous or has a microcrystalline structure.

20. The magnetic memory according to claim 18, wherein said underlayer includes at least one of Ni, Fe and Co as a major constitution, and includes at least one non-magnetic element selected from the group consisting of Zr, Hf, Ti, V, Nb, Ta, W, B and N.

21. The magnetic memory according to claim 18, wherein said data recording layer is formed of n film stacks in each of which first and second layers are layered, where n is a natural number,

wherein said first layer includes at least one material selected from the group consisting of Fe, Co and Ni, and

wherein said second layer is formed of material different from that of said first layer and includes at least one material selected from the group consisting of Fe, Co and Ni.