JP2022034728A - Wiring layer, domain wall moving element and magnetic array - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wiring layer, a domain wall moving element and a magnetic array capable of preventing a single magnetic domain.
SOLUTION: In a domain wall moving element 100, a wiring layer 10 has a domain wall moving layer 11 extending in a first direction and having a domain wall inside, and a portion embedded in the domain wall moving layer, and is made of a material or laminated. It has magnetic bodies 12 and 13 whose structure is different from that of the domain wall moving layer. In the wiring layer, the domain wall moving layer includes a first region A1 outside the central end of the magnetic domain wall end portion of the magnetic material in the first direction X, and a second region A2 other than the first region. Have. The magnetic material may be in contact with the first region.
[Selection diagram] Fig. 3

Description

The present invention relates to a wiring layer, a domain wall moving element and a magnetic array.

Next-generation non-volatile memory is attracting attention as an alternative to flash memory, etc., whose miniaturization has reached its limit. For example, MRAM (Magnetoresistive Random Access Memory), ReRAM (Resitive Random Access Memory), PCRAM (Phase Change Random Access Memory), and the like are known as next-generation non-volatile memory.

The MRAM utilizes the change in resistance value caused by the change in the direction of magnetization for data recording. Data recording is carried out by each of the magnetoresistance changing elements constituting the MRAM. For example, Patent Document 1 describes a magnetoresistance changing element (domain wall moving element) capable of recording multi-valued data by moving a magnetic wall in a first ferromagnetic layer (domain wall moving layer). There is. Patent Document 1 describes that magnetizing fixed regions are formed at both ends of the first ferromagnetic layer in order to control the moving range of the domain wall and prevent the first ferromagnetic layer from becoming a single magnetic domain.

Japanese Patent No. 5445970

The domain wall moving layer to which the domain wall moves often has a magnetization fixing region at both ends in order to prevent the domain wall from reaching one end and disappearing. When the domain wall invades the magnetization fixed region, the domain wall may disappear. Since the domain wall moving element records data at the position of the domain wall, data cannot be recorded when the domain wall disappears.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a wiring layer, a domain wall moving element, and a magnetic array that can further prevent single magnetic domain formation.

(1) The wiring layer according to the first aspect has a domain wall moving layer that extends in the first direction and can have a domain wall inside, and a portion embedded in the domain wall moving layer, and has a material or a laminated structure. It has a magnetic material different from that of the domain wall moving layer.

(2) In the wiring layer according to the above aspect, the domain wall moving layer includes a first region of the ends of the magnetic material outside the central end of the domain wall moving layer in the first direction, and the first region. It has a second region other than one region, and the magnetic material may be in contact with the first region.

(3) The wiring layer according to the above aspect has two magnetic materials, and the two magnetic materials may be separated from each other in the first direction.

(4) The wiring layer according to the above aspect may further include an interlayer region between the magnetic material and the domain wall moving layer.

(5) In the wiring layer according to the above aspect, the magnetic material may have an inclined surface inclined with respect to a surface orthogonal to the first direction at the interface with the domain wall moving layer.

(6) In the wiring layer according to the above aspect, the magnetic material may have a curved curved surface at the interface with the domain wall moving layer.

(7) In the wiring layer according to the above aspect, the magnetic material may be exposed on the first surface in the thickness direction.

(8) In the wiring layer according to the above aspect, the width of the magnetic material in the second direction orthogonal to the first direction may be wider than the width of the domain wall moving layer in the second direction.

(9) In the wiring layer according to the above aspect, the magnetic material may be located at a position overlapping with the first end of the domain wall moving layer in the first direction.

(10) In the wiring layer according to the above aspect, the magnetic material may penetrate the domain wall moving layer in the thickness direction.

(11) The wiring layer according to the above aspect may further include a second magnetic material connected to a portion of the magnetic material exposed from the domain wall moving layer.

(12) In the wiring layer according to the above aspect, the second magnetic material may have an inclined surface inclined with respect to a surface orthogonal to the first direction.

(13) In the wiring layer according to the above aspect, the second magnetic material may also be in contact with the domain wall moving layer.

(14) In the wiring layer according to the above aspect, the magnetic material and the second magnetic material may be integrated.

(15) The wiring layer according to the above aspect may further include a spacer layer between the magnetic material and the second magnetic material.

(16) The domain wall moving element according to the second aspect includes a wiring layer according to the above aspect and a conductor connected to the wiring layer, and the conductor is connected to the magnetic body.

(17) The domain wall moving element according to the third aspect includes the wiring layer according to the above aspect and the conductor connected to the wiring layer, and the conductor is connected to the second magnetic body. There is.

(18) The magnetic wall moving element according to the fourth aspect includes a ferromagnetic layer located at a position overlapping the magnetic wall moving layer in the thickness direction, and a non-magnetic layer between the wiring layer and the ferromagnetic layer. You may prepare.

(19) The domain wall moving element according to the above aspect includes a conductor connected to the wiring layer, and the magnetic body has the conductor and the non-magnetic layer in the first direction when viewed from the thickness direction. It may be between.

(20) The magnetic array according to the fifth aspect has a plurality of domain wall moving elements according to the above aspect.

In the wiring layer, the domain wall moving element, and the magnetic array according to the above aspect, the wiring layer is difficult to be in a single magnetic domain.

It is a block diagram of the magnetic array which concerns on 1st Embodiment. It is sectional drawing of the characteristic part of the magnetic array which concerns on 1st Embodiment. It is sectional drawing of the domain wall moving element which concerns on 1st Embodiment. It is a top view of the domain wall moving element which concerns on 1st Embodiment. It is sectional drawing of the domain wall moving element which concerns on 1st modification. It is sectional drawing of the domain wall moving element which concerns on 2nd modification. It is sectional drawing of the domain wall moving element which concerns on 3rd modification. It is sectional drawing of the domain wall moving element which concerns on 4th modification. It is sectional drawing of the domain wall moving element which concerns on 5th modification. It is sectional drawing of the domain wall moving element which concerns on 6th modification. It is sectional drawing of the domain wall moving element which concerns on 7th modification. It is sectional drawing of the domain wall moving element which concerns on 8th modification. It is a top view of the domain wall moving element which concerns on 9th modification. It is sectional drawing of the domain wall moving element which concerns on 10th modification. It is sectional drawing of the domain wall moving element which concerns on 11th modification.

Hereinafter, the present embodiment will be described in detail with reference to the drawings as appropriate. The drawings used in the following description may be enlarged for convenience in order to make the features of the present invention easy to understand, and the dimensional ratios of each component may differ from the actual ones. be. The materials, dimensions, and the like exemplified in the following description are examples, and the present invention is not limited thereto, and can be appropriately modified and carried out within the range in which the effects of the present invention are exhibited.

First, define the direction. The x-direction and the y-direction are directions substantially parallel to one surface of the substrate Sub (see FIG. 2) described later. The x direction is the direction in which the wiring layer 10 described later extends. The x direction is an example of the first direction. The y direction is a direction orthogonal to the x direction. The y direction is an example of the second direction. The z-direction is a direction from the substrate Sub, which will be described later, toward the domain wall moving element 100. The z direction coincides with, for example, the stacking direction of the wiring layer 10. The z direction is an example of the thickness direction. Further, in the present specification, "extending in the x direction" means that, for example, the dimension in the x direction is larger than the smallest dimension among the dimensions in the x direction, the y direction, and the z direction. The same applies when extending in other directions.

[First Embodiment]
FIG. 1 is a block diagram of a magnetic array according to the first embodiment. The magnetic array 200 includes a plurality of domain wall moving elements 100, a plurality of first wiring Wp, a plurality of second wiring Cm, a plurality of third wiring Rp, a plurality of first switching elements SW1, and a plurality of second wiring elements. It includes a switching element SW2 and a plurality of third switching elements SW3. The magnetic array 200 can be used, for example, in a magnetic memory, a product-sum calculator, a neuromorphic device, and a magneto-optical element.

<1st wiring, 2nd wiring, 3rd wiring>
Each of the first wiring Wp is a writing wiring. Each of the first wirings Wp electrically connects a power source and one or more domain wall moving elements 100. The power supply is connected to one end of the magnetic array 200 during use.

Each of the second wiring Cm is a common wiring. The common wiring is wiring that can be used both when writing data and when reading data. Each of the second wiring Cm electrically connects the reference potential and one or more domain wall moving elements 100. The reference potential is, for example, ground. The second wiring Cm may be provided in each of the plurality of domain wall moving elements 100, or may be provided over the plurality of domain wall moving elements 100.

Each of the third wiring Rp is a read wiring. Each of the third wiring Rp electrically connects the power supply and one or more domain wall moving elements 100. The power supply is connected to one end of the magnetic array 200 during use.

<1st switching element, 2nd switching element, 3rd switching element>
In FIG. 1, a first switching element SW1, a second switching element SW2, and a third switching element SW3 are connected to each of the plurality of domain wall moving elements 100. The first switching element SW1 is connected between the domain wall moving element 100 and the first wiring Wp. The second switching element SW2 is connected between the domain wall moving element 100 and the second wiring Cm. The third switching element SW3 is connected between the domain wall moving element 100 and the third wiring Rp.

When the first switching element SW1 and the second switching element SW2 are turned on, a write current flows between the first wiring Wp and the second wiring Cm connected to the predetermined domain wall moving element 100. When the second switching element SW2 and the third switching element SW3 are turned on, a read current flows between the second wiring Cm and the third wiring Rp connected to the predetermined domain wall moving element 100.

The first switching element SW1, the second switching element SW2, and the third switching element SW3 are elements that control the flow of current. The first switching element SW1, the second switching element SW2, and the third switching element SW3 are, for example, a transistor, an element utilizing a phase change of a crystal layer such as an Ovonic Threshold Switch (OTS), and a metal insulator transition. An element such as a (MIT) switch that utilizes a change in band structure, an element that utilizes a breakdown voltage such as a Zener diode and an avalanche diode, and an element whose conductivity changes as the atomic position changes.

Any one of the first switching element SW1, the second switching element SW2, and the third switching element SW3 may be shared by the domain wall moving element 100 connected to the same wiring. For example, when sharing the first switching element SW1, one first switching element SW1 is provided upstream of the first wiring Wp. For example, when sharing the second switching element SW2, one second switching element SW2 is provided upstream of the second wiring Cm. For example, when sharing the third switching element SW3, one third switching element SW3 is provided upstream of the third wiring Rp.

FIG. 2 is a cross-sectional view of a main part of the magnetic array 200 according to the first embodiment. FIG. 2 is a cross section of one domain wall moving element 100 in FIG. 1 cut along an xz plane passing through the center of the width of the wiring layer 10 in the y direction.

The first switching element SW1 and the second switching element SW2 shown in FIG. 2 are transistor Trs. The transistor Tr has a gate electrode G, a gate insulating film GI, and a source region S and a drain region D formed on the substrate Sub. The substrate Sub is, for example, a semiconductor substrate. The third switching element SW3 is electrically connected to the third wiring Rp, and is located, for example, at a position displaced in the y direction in FIG.

Each of the transistor Tr and the domain wall moving element 100 are electrically connected to each other via wirings w1 and w2. Wiring w1 and w2 include a material having conductivity. The wiring w1 is a via wiring extending in the z direction. The wiring w2 is an in-plane wiring extending in any direction in the xy plane. The wirings w1 and w2 are formed in the opening of the insulating layer 90.

The insulating layer 90 is an insulating layer that insulates between the wirings of the multilayer wiring and between the elements. The domain wall moving element 100 and the transistor Tr are electrically separated by an insulating layer 90 except for the wirings w1 and w2. The insulating layer 90 is, for example, silicon oxide (SiO _x ), silicon nitride (SiN _x ), silicon carbide (SiC), chromium nitride, silicon carbide (SiCN), silicon oxynitride (SiON), aluminum oxide (Al ₂ O). ₃ ), zirconium oxide (ZrO _x ) and the like.

"Domain wall moving element"
FIG. 3 is a cross-sectional view of the domain wall moving element 100 cut along the xz plane passing through the center of the wiring layer 10 in the y direction. FIG. 4 is a plan view of the domain wall moving element 100 in a plan view from the z direction.

The domain wall moving element 100 has a wiring layer 10, a non-magnetic layer 30, and a ferromagnetic layer 20. The domain wall moving element 100 is covered with an insulating layer 90. When writing data to the domain wall moving element 100, a writing current is passed along the wiring layer 10. When reading data from the domain wall moving element 100, a current is applied in the z direction of the domain wall moving element 100, and a reading current is passed between the electrode E and any wiring w1 connected to the wiring layer 10.

The wiring layer 10 has a domain wall moving layer 11, a magnetic body 12, and a magnetic body 13. The magnetic material 13 is an example of the second magnetic material. The wiring layer 10 is wiring through which a write current flows when data is written.

The domain wall moving layer 11 extends in the x direction. The domain wall moving layer 11 has a plurality of magnetic domains inside, and has a domain wall DW at the boundary of the plurality of magnetic domains. The domain wall moving layer 11 is, for example, a layer capable of magnetically recording information by changing the magnetic state. The domain wall moving layer 11 may be referred to as a ferromagnetic layer or a magnetic recording layer.

The domain wall moving layer 11 has a first region A1 and a second region A2. The first region A1 is a region outside the end portion of the magnetic body 12 in the x direction of the domain wall moving layer 11 on the central side of the magnetic wall moving layer 11 in the x direction. There are, for example, two first regions A1, and the two first regions A1 sandwich the second region A2 in the x direction. The first region A1 is, for example, a region that overlaps with the magnetic body 12 when viewed from the z direction. The second region A2 is a region other than the first region A1 of the domain wall moving layer 11.

The first region A1 is a region in which the direction of magnetization is fixed in one direction. "The direction of magnetization is fixed in one direction" means that the direction of magnetization does not change when an external force is applied to the extent that the magnetization of the second region A2 is reversed. The orientation directions of the magnetizations of the two first regions A1 sandwiching the second region A2 are opposite.

The second region A2 is a region where the direction of magnetization changes and the domain wall DW can move. The second domain A2 has a first magnetic domain A21 and a second magnetic domain A22. The magnetization MA21 of the first magnetic domain _A21 and the magnetization MA22 of the second magnetic domain _A22 have opposite orientation directions. The first magnetic domain A21 has the same magnetization orientation direction as the adjacent first region A1, and the second magnetic domain A22 has the same magnetization orientation direction as the adjacent first region A1.

The boundary between the first magnetic domain A21 and the second magnetic domain A22 is the domain wall DW. In principle, the domain wall DW moves in the second region A2 and does not invade the first region A1.

When the ratio of the first magnetic domain A21 and the second magnetic domain A22 in the second domain A2 changes, the domain wall DW moves. The domain wall DW moves by passing a write current in the x direction of the second region A2. For example, when a write current in the + x direction (for example, a current pulse) is applied to the second region A2, electrons flow in the −x direction opposite to the current, so that the domain wall DW moves in the −x direction. When a current flows from the first magnetic domain A21 to the second magnetic domain A22, the electrons spin-polarized in the second magnetic domain A22 reverse the magnetization MA21 of the first magnetic domain _A21 . When the magnetization MA21 of the first magnetic domain _A21 is magnetized and inverted, the domain wall DW moves in the −x direction.

The domain wall moving layer 11 is made of a magnetic material. The domain wall moving layer 11 preferably has at least one element selected from the group consisting of Co, Ni, Fe, Pt, Pd, Gd, Tb, Mn, Ge, and Ga. Examples of the material used for the domain wall moving layer 11 include a Co and Ni laminated film, a Co and Pt laminated film, a Co and Pd laminated film, a MnGa-based material, a GdCo-based material, and a TbCo-based material. Ferrimagnetic materials such as MnGa-based materials, GdCo-based materials, and TbCo-based materials have a small saturation magnetization, and the threshold current required to move the domain wall DW is small. Further, the Co and Ni laminated film, the Co and Pt laminated film, and the Co and Pd laminated film have a large coercive force, and the moving speed of the domain wall DW becomes slow.

A part of the magnetic body 12 is embedded in the domain wall moving layer 11. The magnetic body 12 is fitted in an opening formed in the domain wall moving layer 11. A part of the magnetic body 12 is embedded in the first region A1. A part of the magnetic body 12 may be exposed from, for example, the domain wall moving layer 11. For example, there are two magnetic bodies 12, which are separated from each other. For example, the two magnetic bodies 12 sandwich the non-magnetic layer 30 in the x direction when viewed from the z direction.

The magnetic body 12 is in contact with the domain wall moving layer 11 on the bottom surface and the side surface, for example. The magnetic material 12 shown in FIG. 3 is exposed on the first surface 10a of the wiring layer 10. The second surface 10b of the wiring layer 10 is flat. The first surface 10a is the surface of the wiring layer 10 on the side in contact with the non-magnetic layer 30, and the second surface 10b is the surface opposite to the first surface 10a. The magnetic material 12 may be contained in the magnetic wall moving layer 11 or may be exposed on the second surface 10b.

As the magnetic material 12, the same material as that of the domain wall moving layer 11 can be used. However, the material or laminated structure of the magnetic body 12 is different from that of the domain wall moving layer 11. The difference in the laminated structure means that the layer structure such as the composition, the material, and the number of layers of the laminated layers is different. The magnetic material 12 may be a single magnetic material or a laminated body having a plurality of layers. When the magnetic material 12 is a single magnetic material, it is easy to manufacture, and when the magnetic material 12 is composed of a plurality of layers, the coercive force and the like can be finely adjusted.

The magnetic body 12 has an inclined surface 12c inclined with respect to the yz plane orthogonal to the x direction at the interface with the domain wall moving layer 11. The inclined surface 12c is, for example, a side surface of the magnetic body 12 on the non-magnetic layer 30 side. When the side surface of the magnetic body 12 is inclined, the contact area between the magnetic body 12 and the domain wall moving layer 11 increases, and the magnetic bond between the magnetic body 12 and the domain wall moving layer 11 is strengthened. Further, since the interface between the magnetic body 12 and the magnetic wall moving layer 11 has a width in the x direction, it is possible to further prevent the magnetic wall DW from invading the first region A1.

As shown in FIG. 4, the shape of the magnetic material 12 seen from the z direction is, for example, a rectangle. The shape of the magnetic body 12 as viewed from the z direction is not limited to this case. For example, the shape of the magnetic material 12 as viewed from the z direction may be rectangular, circular, elliptical, oval, or the like.

Further, as shown in FIG. 4, for example, the width L12 of the magnetic body 12 in the y direction is longer than the width L11 of the domain wall moving layer 11. By extending the boundary between the magnetic body 12 and the domain wall moving layer 11 in the y direction of the domain wall moving layer 11, the magnetic property distribution in the domain wall moving layer 11 in the y direction becomes uniform. When the magnetic property distribution in the y direction in the domain wall moving layer 11 becomes uniform, it is possible to suppress the tilt of the domain wall DW with respect to the y direction.

The magnetic body 13 is not embedded in the magnetic wall moving layer 11 of the magnetic body 12, but is connected to a portion exposed from the magnetic wall moving layer 11. The magnetic body 13 projects from, for example, the upper surface of the domain wall moving layer 11 in the z direction. The magnetic body 13 is in contact with the magnetic body 12. The direction of the magnetization M ₁₃ of the magnetic body 13 is, for example, the same as the direction of the magnetization M ₁₂ of the adjacent magnetic body 12. By stacking the magnetic material 13 on the magnetic material 12, the magnetization of the first region A1 is less likely to be inverted, and the invasion of the domain wall DW into the first region A1 can be further prevented.

As the magnetic material 13, the same material as the magnetic material 12 can be used. The magnetic material 13 and the magnetic material 12 are made of the same material and may be integrated. The magnetic body 13 is a conductor, and also serves as an electrode for connecting the wiring w1 and the wiring layer 10. Further, the heat generated in the ferromagnetic layer 20 is exhausted through the magnetic body 13, and the heat dissipation of the domain wall moving element 100 is enhanced.

The magnetic body 13 has, for example, an inclined surface 13c inclined with respect to the yz surface. The inclined surface 13c is, for example, a side surface of the magnetic body 13 on the non-magnetic layer 30 side. When the side surface of the magnetic body 13 is inclined, the leakage magnetic field from the inclined surface 13c is applied to the first region A1, and the invasion of the domain wall DW into the first region A1 can be further prevented.

Further, as shown in FIG. 4, the shape of the magnetic material 13 when viewed from the z direction is substantially the same as that of the magnetic material 12. Further, for example, the width of the magnetic body 13 in the y direction is substantially the same as the width of the magnetic body 12 in the y direction. The width of the magnetic body 13 in the y direction may be wider than the width of the magnetic body 12 in the y direction.

Wiring w1, which is a conductor, is connected to the magnetic body 13. The magnetic body 13 is connected to the transistor Tr via the wiring w1 or the like.

The non-magnetic layer 30 is located between the domain wall moving layer 11 and the ferromagnetic layer 20. The non-magnetic layer 30 is laminated on one surface of the domain wall moving layer 11.

The non-magnetic layer 30 is made of, for example, a non-magnetic insulator, a semiconductor or a metal. The non-magnetic insulator is, for example, Al ₂ O ₃ , SiO ₂ , MgO, MgAl ₂ O ₄ , and a material in which some of these Al, Si, and Mg are replaced with Zn, Be, and the like. These materials have a large bandgap and excellent insulation. When the non-magnetic layer 30 is made of a non-magnetic insulator, the non-magnetic layer 30 is a tunnel barrier layer. The non-magnetic metal is, for example, Cu, Au, Ag or the like. Non-magnetic semiconductors are, for example, Si, Ge, CuInSe ₂ , CuGaSe ₂ , Cu (In, Ga) Se ₂ and the like.

The thickness of the non-magnetic layer 30 is, for example, 20 Å or more, and may be 25 Å or more. When the thickness of the non-magnetic layer 30 is large, the resistance area product (RA) of the domain wall moving element 100 becomes large. The resistance area product (RA) of the domain wall moving element 100 is preferably 1 × 10 ⁴ Ω μm ² or more, and more preferably 5 × 10 ⁴ Ω μm ² or more. The resistance area product (RA) of the domain wall moving element 100 is the product of the element resistance of one domain wall moving element 100 and the element cross-sectional area of the domain wall moving element 100 (the area of the cut surface obtained by cutting the non-magnetic layer 30 in the xy plane). expressed.

The ferromagnetic layer 20 is laminated on the non-magnetic layer 30. The ferromagnetic layer 20 is located at a position overlapping the second region A2 of the domain wall moving layer 11 in the z direction. The magnetization M ₂₀ of the ferromagnetic layer 20 is less likely to be inverted than the magnetization _{MA 21} and _{MA 22} of the second region A2 of the domain wall moving layer 11. The magnetization M ₂₀ of the ferromagnetic layer 20 does not change its direction when an external force is applied to the extent that the magnetization of the second region A2 is reversed, and is fixed. The ferromagnetic layer 20 may be referred to as a magnetization fixed layer or a magnetization reference layer.

The ferromagnetic layer 20 includes a ferromagnet. The ferromagnetic layer 20 contains, for example, a material that easily obtains a coherent tunnel effect with the domain wall moving layer 11. The ferromagnetic layer 20 is, for example, a metal selected from the group consisting of Cr, Mn, Co, Fe and Ni, an alloy containing one or more of these metals, and at least one of these metals and B, C, and N. Includes alloys and the like containing the above elements. The ferromagnetic layer 20 is, for example, Co—Fe, Co—Fe—B, Ni—Fe.

The ferromagnetic layer 20 may be, for example, a Whistler alloy. The Whisler alloy is a half metal and has a high spin polarizability. The Whisler alloy is an intermetallic compound having a chemical composition of XYZ or X ₂ YZ, where X is a transition metal element or noble metal element of the Co, Fe, Ni or Cu group on the periodic table, and Y is Mn, V. , Cr or a transition metal of Group Ti or an elemental species of X, and Z is a typical element of Group III to Group V. Examples of the Whisler alloy include Co ₂ FeSi, Co ₂ FeGe, Co ₂ FeGa, Co ₂ MnSi, Co ₂ Mn _1-a Fe _a Al _b Si _1-b , and Co ₂ FeGe _1-c Ga _c .

The direction of magnetization of each layer of the domain wall moving element 100 can be confirmed, for example, by measuring the magnetization curve. The magnetization curve can be measured using, for example, MOKE (Magneto Optical Kerr Effect). The measurement by MOKE is a measurement method performed by incident linearly polarized light on an object to be measured and using a magneto-optical effect (magnetic Kerr effect) in which rotation in the polarization direction occurs.

Next, a method of manufacturing the magnetic array 200 will be described. The magnetic array 200 is formed by a laminating step of each layer and a processing step of processing a part of each layer into a predetermined shape. For the lamination of each layer, a sputtering method, a chemical vapor deposition (CVD) method, an electron beam vapor deposition method (EB vapor deposition method), an atomic laser deposit method, or the like can be used. Processing of each layer can be performed using photolithography or the like.

First, impurities are doped at a predetermined position on the substrate Sub to form a source region S and a drain region D. Next, a gate insulating film GI and a gate electrode G are formed between the source region S and the drain region D. The source region S, the drain region D, the gate insulating film GI, and the gate electrode G form the transistor Tr.

Next, the insulating layer 90 is formed so as to cover the transistor Tr. Further, the wiring w1 is formed by forming an opening in the insulating layer 90 and filling the opening with a conductor. The first wiring Wp, the second wiring Cm, the third wiring Rp, and the wiring w2 are formed by laminating the insulating layer 90 to a predetermined thickness, forming a groove in the insulating layer 90, and filling the groove with a conductor. Will be done.

The domain wall moving layer 11 is laminated on the insulating layer 90. The non-magnetic layer 30 and the ferromagnetic layer 20 are laminated on the domain wall moving layer 11. The non-magnetic layer 30 and the ferromagnetic layer 20 are processed into predetermined shapes. An opening is provided at a predetermined position of the domain wall moving layer 11, and the inside of the opening is filled with the magnetic material 12. The magnetic material 13 may be stacked on the magnetic material 12. The domain wall moving layer 11, the magnetic bodies 12, and 13 form the wiring layer 10. By the above procedure, the domain wall moving element 100 is obtained.

In the domain wall moving element 100 according to the first embodiment, the magnetization of the first region A1 is strongly fixed by embedding the magnetic body 12 in the domain wall moving layer 11. As a result, even when an unintended external force or the like is generated, the domain wall DW does not invade the first region A1 and the domain wall moving layer 11 can be prevented from becoming a single magnetic domain.

Although an example of the magnetic array 200 and the domain wall moving element 100 according to the first embodiment has been described in detail, the magnetic array 200 and the domain wall moving element 100 according to the first embodiment are variously modified within the scope of the gist of the present invention.・ Can be changed.

(First modification)
FIG. 5 is a cross-sectional view of the domain wall moving element 101 according to the first modification cut in the xz plane passing through the center of the wiring layer 10 in the y direction. In FIG. 5, the description of the same configuration as in FIG. 3 is omitted.

The domain wall moving element 101 has a spacer layer 14 between the magnetic body 12 and the magnetic body 13. The spacer layer 14 is a non-magnetic layer. The spacer layer 14 is, for example, Ru, Ir, Rh. The magnetic material 12, the spacer layer 14, and the magnetic material 13 are laminated along the openings formed in the insulating layer 90 and the domain wall moving layer 11. For example, the opening is formed at a predetermined position after the magnetic wall moving layer 11, the non-magnetic layer 30, and the ferromagnetic layer 20 are laminated in this order, and the periphery thereof is filled with the insulating layer 90.

The magnetic body 12 and the magnetic body 13 are, for example, antiferromagnetic bonded. The magnetization M _{12 of the magnetic body 12} and the magnetization M ₁₃ of the magnetic body 13 have opposite magnetization orientation directions. As the magnetic material 13, for example, the same material as the magnetic material 12, an antiferromagnetic film, or the like can be used. The magnetic material 12 and the magnetic material 13 may be ferromagnetically coupled. The magnetization M ₁₂ of the magnetic body 12 is strongly fixed by being coupled with the magnetization M ₁₃ of the magnetic body 13.

The product of the film thickness of the magnetic material 12 and the saturation magnetization is substantially the same as the product of the film thickness of the magnetic material 13 and the saturation magnetization. For example, the magnetic material 12 and the magnetic material 13 have a synthetic antiferromagnetic structure with the spacer layer 14 interposed therebetween. The product of the film thickness of the magnetic material 12 and the saturation magnetization may be different from the product of the film thickness of the magnetic material 13 and the saturation magnetization. When the product of the film thickness and the saturation magnetization is different between the magnetic material 12 and the magnetic material 13, it becomes easy to determine the initial state of the magnetization at the time of manufacturing. When the application of the external magnetic field is stopped after the application of the external magnetic field is applied, the magnetization of the magnetic material having the larger product of the film thickness and the saturation magnetization is oriented in the direction of application of the external magnetic field, and the product of the film thickness and the saturation magnetization is small. The magnetization of the magnetic material is oriented in the direction opposite to the direction in which the external magnetic field is applied. Further, the product of the film thickness of the magnetic material 12 connected to the first end of the domain wall moving layer 11 and the saturation magnetization is made larger than the product of the film thickness of the magnetic body 13 and the saturation magnetization, and the second end of the domain wall moving layer 11 is made larger. The product of the film thickness of the magnetic body 12 connected to the portion and the saturation magnetization may be smaller than the product of the film thickness of the magnetic body 13 and the saturation magnetization. With this configuration, the initial state of magnetization can be easily determined by simply applying an external magnetic field in one direction.

The domain wall moving element 101 according to the first modification has the same effect as the domain wall moving element 100 according to the first embodiment. Further, when the magnetic body 12 and the magnetic body 13 are antiferromagnetically coupled, the influence of the leakage magnetic field from the magnetic body 12 and the magnetic body 13 can be reduced.

(Second modification)
FIG. 6 is a cross-sectional view of the domain wall moving element 102 according to the second modification cut in the xz plane passing through the center of the wiring layer 10 in the y direction. In FIG. 6, the description of the same configuration as in FIG. 3 is omitted.

The magnetic body 12 of the domain wall moving element 102 has a curved curved surface 12d that curves at the interface with the domain wall moving layer 11. When the interface between the magnetic material 12 and the domain wall moving layer 11 is curved, local concentration of the writing current can be avoided. This is because the current tends to concentrate on a portion where the shape such as a corner changes rapidly.

The domain wall moving element 102 according to the second modification has the same effect as the domain wall moving element 100 according to the first embodiment. Further, by suppressing the local concentration of the writing current, it is possible to suppress the deviation of the current density and the heat generation at the interface between the magnetic material 12 and the domain wall moving layer 11.

(Third modification example)
FIG. 7 is a cross-sectional view of the domain wall moving element 103 according to the third modification cut in the xz plane passing through the center of the wiring layer 10 in the y direction. In FIG. 7, the description of the same configuration as in FIG. 3 is omitted.

The domain wall moving element 103 has an interlayer region 15 between the magnetic body 12 and the domain wall moving layer 11. In the interlayer region 15, for example, elements constituting the domain wall moving layer 11 and dissimilar elements are mixed. The dissimilar elements are, for example, heavy metal elements such as Fe, Co, Ni, Cu, Ta, Ru, Pd, Pt, and W, and rare gas elements such as Ar, Kr, and Xe.

The dissimilar element becomes a trap site of the domain wall DW and inhibits the movement of the domain wall DW. Further, when a different element is driven, the interface between the domain wall moving layer 11 and the magnetic body 12 becomes uneven, and the contact area between the domain wall moving layer 11 and the magnetic body 12 increases. When the contact area between the domain wall moving layer 11 and the magnetic body 12 increases, the magnetic coupling between the domain wall moving layer 11 and the magnetic body 12 is strengthened, and the magnetization of the first region A1 is strongly fixed.

In addition, the domain wall moving element 103 according to the third modification can obtain the same effect as the domain wall moving element 100 according to the first embodiment.

(Fourth modification)
FIG. 8 is a cross-sectional view of the domain wall moving element 104 according to the fourth modification cut in the xz plane passing through the center of the wiring layer 10 in the y direction. In FIG. 8, the description of the same configuration as in FIG. 3 is omitted.

The domain wall moving element 104 is at a position where the magnetic body 12 overlaps the first end of the domain wall moving layer 11 in the z direction. A part of the magnetic body 12 protrudes from the domain wall moving layer 11 in the x direction.

When the magnetic body 12 is located at the end of the domain wall moving layer 11, the second region A2 can be widely secured. The domain wall DW moves in the second region A2, and the domain wall moving element 104 stores data according to the position of the domain wall DW. By expanding the moving range of the domain wall DW, it is possible to increase the gradation of the data of the domain wall moving element 104.

In addition, the domain wall moving element 104 according to the fourth modification can obtain the same effect as the domain wall moving element 100 according to the first embodiment.

(Fifth modification)
FIG. 9 is a cross-sectional view of the domain wall moving element 105 according to the fifth modification cut in the xz plane passing through the center of the wiring layer 10 in the y direction. In FIG. 9, the description of the same configuration as in FIG. 3 is omitted.

In the domain wall moving element 105, the magnetic body 12 penetrates the domain wall moving layer 11 in the z direction. A part of the magnetic body 12 protrudes from the lower surface of the domain wall moving layer 11.

The domain wall moving element 105 according to the fifth modification has the same effect as the domain wall moving element 100 according to the first embodiment. Further, when the magnetic body 12 penetrates the magnetic wall moving layer 11, the magnetic body 12 divides the magnetic wall moving layer 11 in the x direction, so that the magnetic wall DW can be further prevented from reaching the end of the magnetic wall moving layer 11.

(6th modification)
FIG. 10 is a cross-sectional view of the domain wall moving element 106 according to the sixth modification cut in the xz plane passing through the center of the wiring layer 10 in the y direction. In FIG. 10, the description of the same configuration as in FIG. 3 is omitted.

In the domain wall moving element 106, the magnetic body 13 is in contact with the magnetic body 12 and the domain wall moving layer 11. The width of the lower surface of the magnetic body 13 in the x direction is, for example, wider than the width of the upper surface of the magnetic body 12 in the x direction.

The domain wall moving element 106 according to the sixth modification has the same effect as the domain wall moving element 100 according to the first embodiment. Further, since the magnetization of the first region A1 is fixed by the magnetic material 12 and the magnetic material 13, the magnetization of the first region A1 is less likely to be inverted.

(7th modification)
FIG. 11 is a cross-sectional view of the domain wall moving element 107 according to the seventh modification cut in the xz plane passing through the center of the wiring layer 10 in the y direction. In FIG. 11, the description of the same configuration as in FIG. 3 will be omitted.

The domain wall moving element 107 does not have a magnetic body 13. Wiring w1, which is a conductor, is directly connected to the magnetic body 12 of the domain wall moving element 107.

The domain wall moving element 107 according to the seventh modification has the same effect as the domain wall moving element 100 according to the first embodiment.

(8th modification)
FIG. 12 is a cross-sectional view of the domain wall moving element 108 according to the eighth modification cut in the xz plane passing through the center of the wiring layer 10 in the y direction. In FIG. 12, the description of the same configuration as in FIG. 3 is omitted.

The domain wall moving element 108 is located at a position where the wiring w1 and the magnetic body 12 do not overlap when viewed from the z direction. The magnetic body 12 is located between the wiring w1 and the non-magnetic layer 30 in the x direction. The wiring w1 is connected to the domain wall moving layer 11 at a position other than the magnetic body 12.

The domain wall moving element 108 according to the eighth modification can obtain the same effect as the domain wall moving element 100 according to the first embodiment. Since the magnetic body 12 is present in front of the point where the write current flows in the wiring w1, it is possible to further prevent the domain wall DW from reaching the end of the domain wall moving layer 11. Further, as the area of the first region A1 becomes larger, the spin polarization of the electrons reaching the second region A2 becomes stronger.

(9th modification)
FIG. 13 is a plan view of the domain wall moving element 109 according to the ninth modification as viewed from the z direction. In FIG. 13, the description of the same configuration as in FIG. 4 will be omitted.

The width L12 of the magnetic body 12 in the y direction is shorter than the width L11 of the domain wall moving layer 11. The magnetic body 12 is in contact with the domain wall moving layer 11 on the bottom surface and the side surface. By also contacting the side surface of the magnetic body 12 in the y direction with the magnetic wall moving layer 11, the contact area between the magnetic wall moving layer 11 and the magnetic body 12 increases.

The domain wall moving element 109 according to the ninth modification has the same effect as the domain wall moving element 100 according to the first embodiment.

(10th modification)
FIG. 14 is a cross-sectional view of the domain wall moving element 110 according to the tenth modification cut in the xz plane passing through the center of the wiring layer 10 in the y direction. In FIG. 14, the description of the same configuration as in FIG. 3 is omitted.

The domain wall moving element 110 does not have the non-magnetic layer 30 and the ferromagnetic layer 20. The domain wall moving element 110 is an optical element utilizing the magneto-optical effect. Depending on the position of the domain wall DW in the domain wall moving layer 11, the phase of the reflected light or the transmitted light of the light incident on the domain wall moving layer 11 changes.

The domain wall moving element 110 according to the tenth modification has the same effect as the domain wall moving element 100 according to the first embodiment.

In addition, the side surface of the magnetic material 12 does not have to be inclined or curved. Further, the magnetic material 12 may not be exposed on the surface of the domain wall moving layer 11 and may be included in the domain wall moving layer 11. Further, unlike the domain wall moving element 111 shown in FIG. 15, the surface to which the wiring w1 is connected to the domain wall moving layer 11 and the surface to which the magnetic body 12 is exposed do not have to coincide.

The preferred embodiments of the present invention have been described in detail above. The characteristic configurations in the embodiments and modifications may be combined.

10 Wiring layer 10a 1st surface 10b 2nd surface 11 Domain wall moving layer 12, 13 Magnetic material 12c, 13c Inclined surface 12d Bay surface 14 Spacer layer 15 Interlayer region 20 Ferromagnetic layer 30 Non-magnetic layer 90 Insulation layer 100, 101, 102 , 103, 104, 105, 106, 107, 108, 109, 110 Domain wall moving element 200 Magnetic array A1 1st region A2 2nd region A21 1st magnetic domain A22 2nd magnetic domain DW domain wall

Claims (20)

A domain wall moving layer that extends in the first direction and can have a domain wall inside,
A wiring layer having a portion embedded in the domain wall moving layer and having a magnetic material having a material or a laminated structure different from that of the domain wall moving layer. The domain wall moving layer has a first region outside the central end of the domain wall moving layer among the ends of the magnetic material in the first direction, and a second region other than the first region. death,
The wiring layer according to claim 1, wherein the magnetic material is in contact with the first region. It has two magnetic materials,
The wiring layer according to claim 1 or 2, wherein the two magnetic materials are separated from each other in the first direction. The wiring layer according to any one of claims 1 to 3, further comprising an interlayer region between the magnetic material and the domain wall moving layer. The wiring layer according to any one of claims 1 to 4, wherein the magnetic material has an inclined surface inclined with respect to a surface orthogonal to the first direction at an interface with the domain wall moving layer. The wiring layer according to any one of claims 1 to 5, wherein the magnetic material has a curved curved surface at an interface with the domain wall moving layer. The wiring layer according to any one of claims 1 to 6, wherein the magnetic material is exposed on the first surface in the thickness direction. The wiring layer according to any one of claims 1 to 7, wherein the width of the magnetic material in the second direction orthogonal to the first direction is wider than the width of the domain wall moving layer in the second direction. The wiring layer according to any one of claims 1 to 8, wherein the magnetic material is located at a position overlapping with the first end of the domain wall moving layer in the first direction. The wiring layer according to any one of claims 1 to 9, wherein the magnetic material penetrates the domain wall moving layer in the thickness direction. The wiring layer according to any one of claims 1 to 10, further comprising a second magnetic material connected to a portion of the magnetic material exposed from the domain wall moving layer. The wiring layer according to claim 11, wherein the second magnetic material has an inclined surface inclined with respect to a surface orthogonal to the first direction. The wiring layer according to claim 11 or 12, wherein the second magnetic material is also in contact with the domain wall moving layer. The wiring layer according to any one of claims 11 to 13, wherein the magnetic material and the second magnetic material are integrated. The wiring layer according to any one of claims 11 to 14, further comprising a spacer layer between the magnetic material and the second magnetic material. The wiring layer according to any one of claims 1 to 15, and the wiring layer.
With a conductor connected to the wiring layer,
The conductor is a domain wall moving element connected to the magnetic body. The wiring layer according to any one of claims 11 to 15, and the wiring layer.
With a conductor connected to the wiring layer,
The conductor is a domain wall moving element connected to the second magnetic body. The wiring layer according to any one of claims 1 to 15, and the wiring layer.
A ferromagnetic layer located at a position overlapping the domain wall moving layer in the thickness direction,
A domain wall moving element including a non-magnetic layer between the wiring layer and the ferromagnetic layer. Further provided with a conductor connected to the wiring layer,
The magnetic domain wall moving element according to claim 18, wherein the magnetic material is located between the conductor and the non-magnetic layer in the first direction when viewed from the thickness direction. A magnetic array having a plurality of domain wall moving elements according to any one of claims 16 to 19.

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