Magnetic storage device

Abstract

To provide a magnetic storage device including a magnetoresistive element having excellent properties. [Solution] The magnetic memory device according to the embodiment comprises: a first magnetic layer 10 having a fixed magnetization direction; a first predetermined element-containing layer 61 containing at least one first predetermined element selected from Sc, Y, Ti, Zr, Hf, Al, Si, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Ho, Dy, Er, Yb, and Lu, and oxygen (O); a second magnetic layer 20 provided between the first magnetic layer and the first predetermined element-containing layer and having a variable magnetization direction; a second predetermined element-containing layer 62 provided between the first predetermined element-containing layer and the second magnetic layer and substantially containing only at least one second predetermined element selected from P, As, Sb, Bi, S, Se, and Te; and a non-magnetic layer 30 provided between the first magnetic layer and the second magnetic layer.

Description

Technical Field

[0004] , , , , , , , , , ,

[0005]

[0001] Embodiments of the present invention relate to a magnetic storage device.

Background Art

[0002] There has been proposed a magnetic storage device in which a plurality of magnetoresistive elements are integrated on a semiconductor substrate.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

[0006] [Figure 1] This is a schematic cross-sectional view showing the basic configuration of a magnetic storage device according to an embodiment. [Figure 2] This is a schematic cross-sectional view showing the basic configuration of a modified example of the magnetic storage device according to the embodiment. [Modes for carrying out the invention]

[0007] The embodiments will be described below with reference to the drawings.

[0008] Figure 1 is a schematic cross-sectional view showing the basic configuration of a magnetic storage device according to an embodiment.

[0009] The structure shown in Figure 1 is provided on a substructure (not shown) including a semiconductor substrate (not shown) and functions as a magnetoresistive element. Specifically, the magnetoresistive element functions as a magnetic tunnel junction (MTJ) element with perpendicular magnetization.

[0010] The magnetic storage device of this embodiment shown in Figure 1 includes a reference layer (first magnetic layer) 10, a storage layer (second magnetic layer) 20, a tunnel barrier layer (non-magnetic layer) 30, a shift canceling layer (third magnetic layer) 40, an intermediate layer 50, a first predetermined element-containing layer 61, and a second predetermined element-containing layer 62, and has a laminated structure in which these layers 10 to 62 are stacked.

[0011] More specifically, a reference layer 10, a storage layer 20, a tunnel barrier layer 30, an intermediate layer 50, and a second predetermined element-containing layer 62 are provided between the shift-canceling layer 40 and the first predetermined element-containing layer 61, the storage layer 20 is provided between the reference layer 10 and the first predetermined element-containing layer 61, the second predetermined element-containing layer 62 is provided between the first predetermined element-containing layer 61 and the storage layer 20, the tunnel barrier layer 30 is provided between the reference layer 10 and the storage layer 20, the reference layer 10 is provided between the tunnel barrier layer 30 and the shift-canceling layer 40, and the intermediate layer 50 is provided between the reference layer 10 and the shift-canceling layer 40.

[0012] The reference layer 10 is a ferromagnetic layer having a fixed magnetization direction and perpendicular magnetization. That is, the magnetization direction of the reference layer 10 is perpendicular to the main surface of the reference layer 10. The reference layer 10 contains at least one element selected from iron (Fe) and cobalt (Co), and may further contain boron (B). In this embodiment, the reference layer 10 is formed of a CoFeB layer containing Co, Fe, and B.

[0013] The memory layer 20 is a ferromagnetic layer having a variable magnetization direction and having perpendicular magnetization. That is, the magnetization direction of the memory layer 20 is perpendicular to the main surface of the memory layer 20. The memory layer 20 contains at least one element selected from iron (Fe) and cobalt (Co), and may further contain boron (B). In this embodiment, the memory layer 20 is formed of a CoFeB layer containing Co, Fe, and B.

[0014] The tunnel barrier layer 30 is provided between the reference layer 10 and the memory layer 20, with one main surface of the tunnel barrier layer 30 in contact with the reference layer 10 and the other main surface of the tunnel barrier layer 30 in contact with the memory layer 20. The tunnel barrier layer 30 is an insulating layer and is formed of an MgO layer containing magnesium (Mg) and oxygen (O).

[0015] The shift-canceling layer 40 is a ferromagnetic layer having a fixed magnetization direction and perpendicular magnetization. That is, the magnetization direction of the shift-canceling layer 40 is perpendicular to the main surface of the shift-canceling layer 40. The shift-canceling layer 40 has a magnetization direction antiparallel to the magnetization direction of the reference layer 10 and has the function of canceling the magnetic field applied from the reference layer 10 to the memory layer 20. Furthermore, the shift-canceling layer 40 has a superlattice structure in which cobalt (Co) and platinum (Pt) are alternately stacked.

[0016] The intermediate layer 50 is formed of an iridium (Ir) layer or a ruthenium (Ru) layer, and a synthetic antiferromagnetic coupling (SAF) is established between the reference layer 10 and the shift-canceling layer 40 via the intermediate layer 50.

[0017] The first predetermined element-containing layer 61 is provided above the memory layer 20 and functions as part of the cap layer.

[0018] The first predetermined element-containing layer 61 contains at least one first predetermined element selected from scandium (Sc), yttrium (Y), titanium (Ti), zirconium (Zr), hafnium (Hf), aluminum (Al), silicon (Si), lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), holmium (Ho), dysprosium (Dy), erbium (Er), ytterbium (Yb), and lutetium (Lu), and oxygen (O). That is, the first predetermined element-containing layer 61 is an oxide layer containing at least one first predetermined element and oxygen (O).

[0019] The second predetermined element-containing layer 62 is provided between the memory layer 20 and the first predetermined element-containing layer 61 and functions as part of the cap layer. One main surface of the second predetermined element-containing layer 62 is in contact with the first predetermined element-containing layer 61, and the other main surface of the second predetermined element-containing layer 62 is in contact with the memory layer 20.

[0020] The second predetermined element-containing layer 62 substantially contains only at least one second predetermined element selected from phosphorus (P), arsenic (As), antimony (Sb), bismuth (Bi), sulfur (S), selenium (Se), and tellurium (Te). That is, the second predetermined element-containing layer 62 may be substantially formed of only one second predetermined element or may be substantially formed of two or more second predetermined elements. The second predetermined element-containing layer 62 preferably has a thickness of 1 nm or less.

[0021] Note that "substantially contains" and "substantially formed" mean that a layer containing the intended element is allowed to contain a small amount of unintended elements other than the intended element.

[0022] As described above, in the present embodiment, by providing the first predetermined element-containing layer 61 and the second predetermined element-containing layer 62, the perpendicular magnetic anisotropy of the memory layer 20 can be enhanced, and it is possible to obtain a magnetoresistive element having excellent characteristics. The following description will be added.

[0023] In order to obtain a magnetoresistive element having excellent characteristics, it is important to enhance the perpendicular magnetic anisotropy of the memory layer. However, as the size of the magnetoresistive element decreases, it becomes difficult to obtain a memory layer having high perpendicular magnetic anisotropy.

[0024] In the present embodiment, the second predetermined element-containing layer 62 is provided adjacent to the memory layer 20. The second predetermined element is selected from P, As, Sb, and Bi which are semimetal pnictogen elements, and S, Se, and Te which are chalcogen elements. The second predetermined element-containing layer 62 substantially contains only at least one second predetermined element. By providing such a second predetermined element-containing layer 62 adjacent to the memory layer 20, it is possible to enhance the interfacial magnetic anisotropy of the memory layer 20.

[0025] However, if only the second predetermined element-containing layer 62 is provided on the memory layer 20, there is a possibility that a stable second predetermined element-containing layer 62 may not be formed.

[0026] In the present embodiment, the first predetermined element-containing layer 61 is provided adjacent to the second predetermined element-containing layer 62. As already described, the first predetermined element-containing layer 61 is an oxide layer containing at least one first predetermined element and oxygen (O). By providing such a first predetermined element-containing layer 61 adjacent to the second predetermined element-containing layer 62, it is possible to stabilize the second predetermined element-containing layer 62. Specifically, by the first predetermined element contained in the first predetermined element-containing layer 61 and the second predetermined element contained in the second predetermined element-containing layer 62 combining with each other, it becomes possible to stabilize the second predetermined element-containing layer 62.

[0027] <0Therefore, in this embodiment, the second predetermined element-containing layer 62 can be stabilized by the first predetermined element-containing layer 61, and the perpendicular magnetic anisotropy of the storage layer 20 can be increased by the stabilized second predetermined element-containing layer 62.

[0028] Figure 2 is a schematic cross-sectional view showing the basic configuration of a modified example of the magnetic storage device according to this embodiment.

[0029] The basic structure of this modified example is the same as that of the embodiment described above. However, while the magnetoresistive element in the embodiment described above was a top-free type magnetoresistive element in which the memory layer 20 is located on the upper side of the reference layer 10, this modified example is a bottom-free type magnetoresistive element in which the memory layer 20 is located on the lower side of the reference layer 10. Therefore, the stacking order of layers 10 to 62 in this modified example is the reverse of the stacking order of layers 10 to 62 in the embodiment described above.

[0030] In the embodiment shown in Figure 1, the first predetermined element-containing layer 61 and the second predetermined element-containing layer 62 function as cap layers, but in this modified example, the first predetermined element-containing layer 61 and the second predetermined element-containing layer 62 function as base layers.

[0031] Thus, the basic structure of this modified example is the same as that of the embodiment described above, and it is possible to obtain the same effects as those of the embodiment described above with this modified example as well.

[0032] While several embodiments of the present invention have been described, these embodiments are presented as examples only and are not intended to limit the scope of the invention. These novel embodiments can be carried out in a variety of other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims of the invention and its equivalents. [Explanation of Symbols]

[0033] 10...Reference layer (first magnetic layer) 20...Memory layer (second magnetic layer) 30...Tunnel barrier layer (non-magnetic layer) 40... Shift-canceling layer (third magnetic layer) 50…Middle class 61...First predetermined element-containing layer 62...Second predetermined element-containing layer

Claims

1. A first magnetic layer having a fixed magnetization direction, A first predetermined element-containing layer containing at least one first predetermined element selected from scandium (Sc), yttrium (Y), titanium (Ti), zirconium (Zr), hafnium (Hf), aluminum (Al), silicon (Si), lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), holmium (Ho), dysprosium (Dy), erbium (Er), ytterbium (Yb), and lutetium (Lu), and oxygen (O), A second magnetic layer having a variable magnetization direction is provided between the first magnetic layer and the first predetermined element-containing layer, A second predetermined element-containing layer is provided between the first predetermined element-containing layer and the second magnetic layer, and substantially contains only at least one second predetermined element selected from phosphorus (P), arsenic (As), antimony (Sb), bismuth (Bi), sulfur (S), selenium (Se), and tellurium (Te), A non-magnetic layer provided between the first magnetic layer and the second magnetic layer, A magnetic storage device characterized by comprising the following features.

2. The second magnetic layer contains at least one element selected from iron (Fe) and cobalt (Co). The magnetic storage device according to claim 1.

3. The second magnetic layer further contains boron (B). The magnetic storage device according to claim 2.

4. The non-magnetic layer contains magnesium (Mg) and oxygen (O). The magnetic storage device according to claim 1.

5. The second predetermined element-containing layer is in contact with the first predetermined element-containing layer. The magnetic storage device according to claim 1.

6. The second predetermined element-containing layer is in contact with the second magnetic layer. The magnetic storage device according to claim 1.

7. The second magnetic layer is in contact with the non-magnetic layer. The magnetic storage device according to claim 1.

8. The second magnetic layer has perpendicular magnetization. The magnetic storage device according to claim 1.

9. The second predetermined element-containing layer has a thickness of 1 nm or less. The magnetic storage device according to claim 1.

10. The present invention further comprises a third magnetic layer having a magnetization direction antiparallel to the magnetization direction of the first magnetic layer, The first magnetic layer is provided between the non-magnetic layer and the third magnetic layer. The magnetic storage device according to claim 1.

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