JP2020141132A - Magnetic domain wall movement element and magnetic recording array - Google Patents

Abstract

To provide a magnetic domain wall movement type magnetic recording element and a magnetic memory which have a wide range of change in resistance.SOLUTION: A magnetic domain wall movement type magnetic recording element according to the present embodiment includes a first ferromagnetic layer, a magnetic recording layer, a nonmagnetic layer, a first electrode, and a second electrode. The first electrode includes a magnetic material whose magnetization is oriented in a direction different from a direction of magnetization of the first ferromagnetic layer. The magnetic recording layer includes: a first region which overlaps with the first electrode and the first ferromagnetic layer in a first direction; a second region which overlaps with the second electrode and the first ferromagnetic layer in the first direction; and a third region which is sandwiched between the first region and the second region. An area of a first portion in the first region facing the first electrode is larger than an area of a second portion in the second region facing the second electrode. The first ferromagnetic layer overlaps with a part of the first electrode and a part of the second electrode in the first direction.SELECTED DRAWING: Figure 1

Description

The present invention relates to domain wall moving elements and magnetic recording arrays.

Attention is focused on next-generation non-volatile memory that will replace flash memory, etc., whose miniaturization has reached its limit. For example, MRAM (Magnetoresistive Random Access Memory), ReRAM (Resistance Random Access Memory), PCRAM (Phase Change Random Access Memory), and the like are known as next-generation non-volatile memories.

The MRAM utilizes the change in resistance value caused by the change in the direction of magnetization for data recording. In order to realize a large capacity of the recording memory, miniaturization of the elements constituting the memory and increasing the number of recording bits per element constituting the memory are being studied.

Patent Document 1 describes a magnetoresistive element that utilizes the movement of a domain wall. The magnetoresistive element described in Patent Document 1 records information in analog depending on the position of the domain wall. The magnetoresistive element described in Patent Document 1 controls the range in which the domain wall can move by the magnetization fixing portion.

Japanese Patent No. 5598697

The resistance value of the domain wall moving element changes according to the difference in the relative angles of magnetization of the two ferromagnets sandwiching the non-magnetic layer. The domain wall moving element stores data based on the resistance value. In the domain wall moving element, in order to prevent the domain wall from disappearing, a magnetization fixing portion may be provided in the magnetic recording layer in which the domain wall moves. Further, in order to increase the degree of integration of the plurality of domain wall moving elements, a reference layer as a reference for resistance change may be laminated on one surface of the magnetic recording layer including the magnetization fixing portion. The direction of magnetization is fixed in the magnetization fixing portion, and the relative angle between the magnetization of the magnetization fixing portion and the magnetization of the reference layer does not change. Therefore, the magnetization fixing portion does not generate a change in the resistance value of the domain wall moving element, and the resistance change width becomes smaller by the amount that the magnetization fixing layer and the reference layer overlap in a plan view. When the range of change in the resistance value is large, for example, it is possible to suppress fluctuations in the data recorded by the domain wall moving element due to noise.

The present invention has been made in view of the above problems, and provides a stable magnetic domain wall moving magnetic recording element having a wide resistance change range and a magnetic memory.

(1) The magnetic wall moving element according to the first aspect includes a first ferromagnetic layer, a magnetic recording layer located in the first direction with respect to the first ferromagnetic layer and extending in the second direction, and the first. The non-magnetic layer located between the ferromagnetic layer and the magnetic recording layer and the magnetic recording layer located on the opposite side of the non-magnetic layer and overlapping a part of the magnetic recording layer in the first direction. A first electrode and a second electrode are provided, the first electrode contains a magnetic material whose magnetization is oriented in a direction different from the direction of magnetization of the first ferromagnetic layer, and the magnetic recording layer is the first. A first region that overlaps the electrode and the first ferromagnetic layer in the first direction, a second region that overlaps the second electrode and the first ferromagnetic layer in the first direction, and the first region and the first region. It has a third region sandwiched between the two regions, and the area of the first portion of the first region facing the first electrode is the area of the second portion of the second region facing the second electrode. More broadly, the first ferromagnetic layer overlaps the first electrode and a part of the second electrode when viewed from the first direction.

(2) In the domain wall moving element according to the above aspect, the second electrode may include a magnetic material whose magnetization is oriented in the same direction as the magnetization direction of the first ferromagnetic layer.

(3) The domain wall moving element according to the above aspect further includes a substrate, and the first ferromagnetic layer may be located closer to the substrate than the magnetic recording layer.

(4) The magnetic wall moving element according to the above aspect may further have an insulating layer covering the third region of the magnetic recording layer.

(5) The domain wall moving element according to the above aspect further includes a substrate, and the first ferromagnetic layer may be located farther from the substrate than the magnetic recording layer.

(6) In the domain wall moving element according to the above aspect, the side surface of the magnetic recording layer in the second direction may be inclined with respect to the first direction.

(7) In the domain wall moving element according to the above aspect, the first electrode may have a first inclined portion that is inclined with respect to the first direction.

(8) A cut surface extending in the first direction and the second direction through the center of the third direction orthogonal to the first direction and the second direction of the magnetic recording layer of the domain wall moving element according to the above aspect. The first electrode has a first side surface and a second side surface located closer to the second electrode than the first side surface, and the first side surface is the first side surface of the second side surface. It may have a portion having an inclination angle larger than the inclination angle with respect to the direction.

(9) A cut surface extending in the first direction and the second direction through the center of the third direction orthogonal to the first direction and the second direction of the magnetic recording layer of the domain wall moving element according to the above aspect. The first electrode has a first side surface and a second side surface located closer to the second electrode than the first side surface, and the first side surface has no inclination with respect to the first direction. It may have a continuously changing portion.

(10) The magnetic recording array according to the second aspect may have a plurality of domain wall moving elements according to the above aspect.

According to the domain wall moving element and the magnetic recording array according to the above aspect, the resistance change width can be widened.

It is sectional drawing of the semiconductor device which concerns on 1st Embodiment. It is sectional drawing of the memory element which concerns on 1st Embodiment. It is a top view of the memory element which concerns on 1st Embodiment. It is a top view of the 1st modification of the storage element of the semiconductor device which concerns on 1st Embodiment. It is sectional drawing of the 2nd modification of the storage element of the semiconductor device which concerns on 1st Embodiment. It is sectional drawing of the 3rd modification of the storage element of the semiconductor device which concerns on 1st Embodiment. It is a plane schematic diagram of the 3rd modification of the storage element of the semiconductor device which concerns on 1st Embodiment. It is sectional drawing of the 4th modification of the storage element of the semiconductor device which concerns on 1st Embodiment. It is sectional drawing of the 5th modification of the storage element which concerns on 1st Embodiment. It is sectional drawing of the semiconductor device which concerns on 2nd Embodiment. It is sectional drawing of the storage element of the semiconductor device which concerns on 2nd Embodiment. It is sectional drawing of the 6th modification of the storage element which concerns on 2nd Embodiment. It is a block diagram of the magnetic recording array which concerns on 3rd Embodiment.

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 the respective components may differ from the actual ones. is there. The materials, dimensions, etc. 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 60, which will be described later. The x direction is the direction in which the magnetic recording layer 20, which will be described later, extends. The x direction is an example of the second direction. The y direction is a direction orthogonal to the x direction. The z direction is a direction orthogonal to the x direction and the y direction. The z direction is an example of the first 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 minimum dimension among the dimensions in the x direction, the y direction, and the z direction. The same applies when extending in the other direction.

[First Embodiment]
<Semiconductor device>
FIG. 1 is a cross-sectional view of the semiconductor device according to the first embodiment. FIG. 1 is a cross section cut along an xz plane passing through the center of the width of the magnetic recording layer 20 in the y direction. The semiconductor device 200 has a plurality of storage elements 100 and a semiconductor element (for example, a transistor) connected to the storage element 100. In FIG. 1, for convenience, three transistors focused on one storage element 100 and connected to the storage element 100 are illustrated. The semiconductor device 200 includes a first ferromagnetic layer 10, a magnetic recording layer 20, a non-magnetic layer 30, a first electrode 40, a second electrode 50, a substrate 60, a third electrode 70, a plurality of insulating layers 80, and a plurality of conductive portions. It has 90, a first wiring Cm, a second wiring Wp, a third wiring Rp, a plurality of gate electrodes G1, G2, G3, and a plurality of gate insulating films GI1, GI2, GI3. The first ferromagnetic layer 10, the magnetic recording layer 20, the non-magnetic layer 30, the first electrode 40, and the second electrode 50 are referred to as a storage element 100. The storage element 100 is an example of a domain wall moving element. The semiconductor device 200 shown in FIG. 1 has a top pin structure in which the magnetic recording layer 20 is located closer to the substrate 60 than the first ferromagnetic layer 10.

"Substrate, gate electrode, gate insulating film"
The substrate 60 is, for example, a semiconductor substrate. The substrate 60 has a plurality of source regions S1, S2, S3 and a plurality of drain regions D1, D2, D3. The plurality of source regions S1, S2, S3 and the plurality of drain regions D1, D2, D3 are regions in which impurities are injected into the substrate 60. The source region S1, the drain region D1, the gate electrode G1, and the gate insulating film GI1 serve as the first transistor Tr1. The source region S2, the drain region D2, the gate electrode G2, and the gate insulating film GI2 serve as the second transistor Tr2. The source region S3, the drain region D3, the gate electrode G3, and the gate insulating film GI3 serve as a third transistor Tr3.

"Insulation layer"
The insulating layer 80 is an insulating layer that insulates between the wirings of the multilayer wiring and between the elements. The insulating layer 80 electrically separates the substrate 60, the first wiring Cm, the second wiring Wp, the third wiring Rp, and the storage element 100, except for the conductive portion 90.

For the insulating layer 80, the same material as that used in semiconductor devices and the like can be used. The insulating layer 80 includes, 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.

"wiring"
The first wiring Cm is a common wiring. The common wiring is wiring used both when writing data and when reading data. The second wiring Wp is a writing wiring. The write wiring is the wiring used when writing data. The third wiring Rp is a read wiring. The read wiring is the wiring used when reading data. When the first transistor Tr1 and the third transistor Tr3 are turned on, the second wiring Wp and the first wiring Cm are electrically connected, and a write current flows through the storage element 100. When the second transistor Tr1 and the third transistor Tr3 are turned on, the third wiring Wp and the first wiring Cm are electrically connected, and a read current flows through the storage element 100.

"Conductive part"
The conductive portion 90 electrically connects each of the first wiring Cm, the second wiring Wp, the third wiring Rp, and the storage element 100 to the substrate 60. The conductive portion 90 contains a material having conductivity. The conductive portion 91 electrically connects the second wiring Wp and the source region S1 of the first transistor Tr1. The conductive portion 92 electrically connects the second electrode 50 and the drain region D1 of the first transistor Tr1. The conductive portion 93 electrically connects the third wiring Rp and the source region S2 of the second transistor Tr2. The conductive portion 94 electrically connects the wiring 71 and the drain region D2 of the second transistor Tr2. The conductive portion 95 electrically connects the first wiring Cm and the source region S3 of the third transistor Tr3. The conductive portion 96 electrically connects the first electrode 40 and the drain region D3 of the third transistor Tr3. The conductive portions 91, 92, 93, 94, 95, 96 extend in the z direction.

"Third electrode"
The third electrode 70 is an electrode for passing a read current through the storage element 100. The third electrode 70 contains a material having conductivity. The third electrode 70 and the conductive portion 94 are connected by a wiring 71.

"Memory element"
FIG. 2 is an enlarged cross-sectional view of the vicinity of the storage element 100 of the semiconductor device according to the first embodiment. FIG. 3 is a plan view of the storage element 100 of the semiconductor device according to the first embodiment. The storage element 100 has a first ferromagnetic layer 10, a magnetic recording layer 20, a non-magnetic layer 30, a first electrode 40, and a second electrode 50. FIG. 2 is a cross-sectional view of the storage element 100 cut along the xz plane (plane AA in FIG. 3) passing through the center of the magnetic recording layer in the y direction. In FIG. 2, for the sake of simplicity, the insulating layer 80 around the magnetic recording layer 20, the non-magnetic layer 30, and the first ferromagnetic layer 10 is omitted.

"1st electrode, 2nd electrode"
The first electrode 40 and the second electrode 50 are located on the opposite side of the non-magnetic layer 30 with respect to the magnetic recording layer 20. The first electrode 40 and the second electrode 50 are inside the insulating layer 80. The first electrode 40 is located between the magnetic recording layer 20 and the conductive portion 96, and the second electrode 50 is located between the magnetic recording layer 20 and the conductive portion 92. At least a part of the first electrode 40 overlaps with the magnetic recording layer 20 in the z direction. At least a part of the second electrode 50 overlaps the magnetic recording layer 20 in the z direction.

The plan-view shapes of the first electrode 40 and the second electrode 50 from the z direction are not particularly limited. For example, the first electrode 40 and the second electrode 50 shown in FIG. 3 are rectangular in a plan view from the z direction.

The first electrode 40 contains a magnetic material. The first electrode 40 has, for example, a magnetization M ₄₀ oriented in one direction. The orientation of the magnetization M ₄₀ of the first electrode 40 is different from the orientation of the magnetization M ₁₀ of the first ferromagnetic layer 10. The magnetization M ₄₀ shown in FIG. 2 is oriented in the −z direction, for example. The coercive force of the first electrode 40 is larger than the coercive force of the third region R3 of the magnetic recording layer 20, which will be described later. The coercive force of the third region R3 substantially coincides with the coercive force of the magnetic recording layer 20 when the magnetic recording layer 20 is formed on the insulating layer 80 having no first electrode 40 and the second electrode 50.

The coercive force difference between the first electrode 40 and the third region R3 can be adjusted by selecting the material constituting the first electrode 40 and the material constituting the magnetic recording layer 20. Further, the first electrode 40 may have a synthetic antiferromagnetic structure (SAF structure). The synthetic antiferromagnetic structure consists of two magnetic layers sandwiching a non-magnetic layer. The magnetization of each of the two magnetic layers is fixed, and the directions of the fixed magnetization are opposite. For example, a non-magnetic layer and a ferromagnetic layer are provided below the first electrode 40 shown in FIG. The coupling of the first electrode 40 and the ferromagnetic layer increases the coercive force of the first electrode 40.

The first electrode 40 is, for example, a metal selected from the group consisting of Cr, Mn, Co, Fe and Ni, an alloy containing at least one 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 first electrode 40 is, for example, Co-Fe, Co-Fe-B, Ni-Fe, or the like.

The second electrode 50 is a conductor. The second electrode is, for example, Al, Cu, Ag or the like having excellent conductivity.

"Magnetic recording layer"
The magnetic recording layer 20 is located in the z direction of the first electrode 40 and the second electrode 50. The magnetic recording layer 20 is formed so as to straddle the first surfaces 40a and 50a. The magnetic recording layer 20 may be directly connected to the first surfaces 40a and 50a, or may be connected via a layer between them.

The magnetic recording layer 20 is a layer capable of recording information by changing the internal magnetic state. The magnetic recording layer 20 is a magnetic layer located closer to the first electrode 40 and the second electrode 50 than the non-magnetic layer 30. The magnetic recording layer 20 extends in the x direction. The magnetic recording layer 20 shown in FIG. 2 is a rectangle having a long axis in the x direction and a short axis in the y direction in a plan view from the z direction.

The magnetic recording layer 20 has a first magnetic domain 28 and a second magnetic domain 29 inside. The magnetization _{M 28} of the first magnetic domain 28 to the magnetization _{M 29} of the second magnetic domain 29, oriented in opposite directions. The boundary between the first magnetic domain 28 and the second magnetic domain 29 is the domain wall 27. The magnetic recording layer 20 can have a magnetic domain wall 27 inside. Memory element 100 shown in FIG. 2, the magnetization _{M 28} of the first magnetic domain 28 is oriented in the + z-direction, the magnetization _{M 29} of the second magnetic domain 29 is oriented in the -z direction. Hereinafter, an example in which the magnetization is oriented along the z-axis direction will be described, but the magnetization of the magnetic recording layer 20 and the first ferromagnetic layer 10 may be oriented along the x-axis direction, or may be oriented in the xy in-plane. It may be oriented in any of the above directions.

The storage element 100 records data in multiple values or continuously depending on the position of the magnetic domain wall 27 of the magnetic recording layer 20. The data recorded on the magnetic recording layer 20 is read out as a change in the resistance value of the storage element 100 when a read-out current is applied.

The ratio of the first magnetic domain 28 to the second magnetic domain 29 in the magnetic recording layer 20 changes as the domain wall 27 moves. Magnetization _{M 10} of the first ferromagnetic layer 10 is the same direction as the magnetization _{M 28} of the first magnetic domain 28 (parallel), in the opposite direction to the magnetization _{M 29} of the second magnetic domain 29 (antiparallel). When the domain wall 27 moves in the + x direction and the area of the first magnetic domain 28 in the portion overlapping with the first ferromagnetic layer 10 in a plan view from the z direction becomes large, the resistance value of the storage element 100 becomes low. On the contrary, when the domain wall 27 moves in the −x direction and the area of the second magnetic domain 29 in the portion overlapping with the first ferromagnetic layer 10 in the plan view from the z direction becomes large, the resistance value of the storage element 100 increases. ..

The domain wall 27 moves by passing a writing current in the x direction of the magnetic recording layer 20 or applying an external magnetic field. For example, when a write current (for example, a current pulse) is applied in the + x direction of the magnetic recording layer 20, the domain wall 27 moves. At this time, the electrons flow in the −x direction opposite to the current. When a current flows from the first magnetic domain 28 to the second magnetic domain 29, the spin-polarized electrons in the second magnetic domain 29 reverse the magnetization M ₂₈ of the first magnetic domain 28. The magnetic domain wall 27 moves due to the magnetization reversal of the magnetization M _{28 in} the first magnetic domain 28.

The magnetic recording layer 20 can be divided into a plurality of different regions. Hereinafter, the plurality of regions will be referred to as a first region R1, a second region R2, and a third region R3 for convenience. A part of the magnetic recording layer 20 overlaps the first electrode 40 and the second electrode 50 in a plan view from the z direction. The region overlapping the first electrode 40 and the first ferromagnetic layer 10 when viewed from the z direction is referred to as a first region R1. The first region R1 is, for example, a region of the magnetic recording layer 20 that overlaps the upper surface of the first electrode 40 and the lower surface of the first ferromagnetic layer 10, and is, for example, a region where the magnetic recording layer 20 and the first electrode 40 are in contact with each other. This is a region that overlaps with the first ferromagnetic layer 10 in the z direction. The region overlapping the second electrode 50 and the first ferromagnetic layer 10 when viewed from the z direction is referred to as a second region R2. The second region R2 is, for example, a region of the magnetic recording layer 20 that overlaps the upper surface of the second electrode 50 and the lower surface of the first ferromagnetic layer 10, and is, for example, a region where the magnetic recording layer 20 and the second electrode 50 are in contact with each other. This is a region that overlaps with the first ferromagnetic layer 10 in the z direction. The region sandwiched between the first region R1 and the second region R2 is referred to as a third region R3. The third region R3 is, for example, a region excluding the first region R1 and the second region R2. The direction of magnetization of the first region R1 is fixed by the magnetization M ₄₀ of the first electrode 40. The magnetization of the second region R2 is not fixed. However, since the second region R2 is in contact with the second electrode 50, the current density of the second region R2 is smaller than the current density of the third region R3, and the current density when reaching from the third region R3 to the second region R2. The amount of change in is larger than the amount of change in the current density of the current flowing in the third region. Therefore, the domain wall 27 is less likely to enter the second region R2 from the third region R3, and the moving range of the domain wall 27 is limited.

The first region R1 has a first portion R1a. The first portion R1a is a surface facing the first electrode 40 in the first region R1. The first portion R1a is, for example, a surface in contact with the first electrode 40 in the first region R1. The second region R2 has a second portion R2a. The second portion R2a is a surface facing the second electrode 50 in the second region R2. The second portion R2a is, for example, a surface in contact with the second electrode 50 in the second region R2. The area of the first portion R1a is larger than the area of the second portion R2a. In the example shown in FIG. 3, the width w _y of the first portion R1a and the second portion R2a in the y direction is the same, and the width w _x1 of the first portion R1a in the x direction is the width of the second portion R2a in the x direction. _Wider than w _x2 .

The magnetic recording layer 20 is made of a magnetic material. The magnetic material constituting the magnetic recording layer 20 is a metal selected from the group consisting of Cr, Mn, Co, Fe and Ni, an alloy containing one or more of these metals, and B, C, and N of these metals. An alloy or the like containing at least one kind of element can be used. Specific examples thereof include Co-Fe, Co-Fe-B, and Ni-Fe.

The magnetic recording layer 20 preferably has at least one element selected from the group consisting of Co, Ni, Pt, Pd, Gd, Tb, Mn, Ge, and Ga. Examples of the material used for the magnetic recording layer 20 include a Co and Ni laminated film, a Co and Pt laminated film, a Co and Pd laminated film, an 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 is small. Further, the laminated film of Co and Ni, the laminated film of Co and Pt, and the laminated film of Co and Pd have a large coercive force, and the moving speed of the domain wall becomes slow.

"Non-magnetic layer"
The non-magnetic layer 30 is located between the first ferromagnetic layer 10 and the magnetic recording layer 20. The non-magnetic layer 30 is laminated on the second surface 20b of the magnetic recording layer 20. The second surface 20b is a surface facing the first surface 20a.

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 are excellent in insulating properties. 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. Further, the non-magnetic semiconductor is, 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 preferably 20 Å or more, and more preferably 30 Å or more. When the thickness of the non-magnetic layer 30 is large, the resistance area product (RA) of the recording element 100 becomes large. The resistance area product (RA) of the recording element 100 is preferably 1 × 10 ⁵ Ω μm ² or more, and more preferably 1 × 10 ⁶ Ω μm ² or more. The resistance area product (RA) of the recording element 100 is represented by the product of the element resistance of one recording element 100 and the element cross-sectional area of the recording element 100 (the area of the cut surface obtained by cutting the non-magnetic layer 30 in the xy plane). ..

"First ferromagnetic layer"
The first ferromagnetic layer 10 is located in the + z direction of the non-magnetic layer 30. The first ferromagnetic layer 10 faces the non-magnetic layer 30. The first ferromagnetic layer 10 has a portion that overlaps a part of the first electrode 40 and the second electrode 50 when viewed from the z direction. The first ferromagnetic layer 10 partially overlaps the first region R1 and the second region R2 when viewed from the z direction.

The first ferromagnetic layer 10 is a magnetization fixed layer having a magnetization M ₁₀ oriented in one direction. The orientation direction of the magnetization M ₁₀ is opposite to the orientation direction of the magnetization M ₄₀ of the first electrode 40. In the magnetization fixed layer, the direction of magnetization is less likely to change than that in the magnetic recording layer 20 when a predetermined external force is applied. The predetermined external force is, for example, an external force applied to the magnetization by an external magnetic field or an external force applied to the magnetization by a spin polarization current.

The first ferromagnetic layer 10 contains a ferromagnet. Examples of the ferromagnetic material constituting the first ferromagnetic layer 10 include a metal selected from the group consisting of Cr, Mn, Co, Fe and Ni, an alloy containing one or more of these metals, and these metals and B. , C, and N can be used as an alloy containing at least one or more elements. Specific examples thereof include Co-Fe, Co-Fe-B, and Ni-Fe.

The material constituting the first ferromagnetic layer 10 may be 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 Ti group transition metal or X elemental species, 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 thickness of the first ferromagnetic layer 10 is preferably 1.5 nm or less, preferably 1.0 nm or less, when the easy axis of magnetization of the first ferromagnetic layer 10 is in the z direction (perpendicular magnetization film). Is more preferable. When the thickness of the first ferromagnetic layer 10 is reduced, the first ferromagnetic layer 10 is perpendicularly magnetic anisotropy (interfacial vertical magnetism) at the interface between the first ferromagnetic layer 10 and another layer (non-magnetic layer 30). Anisotropy) can be added. The magnetization of the first ferromagnetic layer 10 tends to be oriented in the z direction.

The magnetization of the first ferromagnetic layer 10 is fixed in the z direction as an example. When fixing the magnetization in the z direction, the first ferromagnetic layer 10 is a ferromagnet selected from the group consisting of Co, Fe, and Ni, and non-magnetic selected from the group consisting of Pt, Pd, Ru, and Rh. It is preferable to form a body and a laminate, and it is more preferable to insert a non-magnetic material selected from the group consisting of Ir and Ru as an intermediate layer at any position of the laminate. Vertical magnetic anisotropy can be added by laminating a ferromagnetic material and a non-magnetic material, and the magnetization of the first ferromagnetic layer 10 can be more strongly fixed in the vertical direction by inserting an intermediate layer.

The first ferromagnetic layer 10 may have a SAF structure. An antiferromagnetic layer may be provided on the surface of the first ferromagnetic layer 10 opposite to the non-magnetic layer 30 via a spacer layer. When the first ferromagnetic layer 10 and the antiferromagnetic layer are antiferromagnetic coupled, the coercive force of the first ferromagnetic layer 10 becomes large. The antiferromagnetic layer is, for example, IrMn, PtMn, or the like. The spacer layer contains, for example, at least one selected from the group consisting of Ru, Ir, Rh.

The semiconductor device according to the first embodiment is obtained by laminating each layer and processing 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. The processing of each layer can be performed by using photolithography or the like.

In the storage element 100 according to the first embodiment, when the area of the first portion R1a of the first region R1 becomes wider than the area of the second portion R2a of the second region R2, the width of the resistance change of the storage element 100 (dynamic range). Spreads.

The resistance value of the storage element 100 changes based on the difference in the relative angles of magnetization of the two ferromagnets (first ferromagnet layer 10 and magnetic recording layer 20) sandwiching the non-magnetic layer 30. The first ferromagnetic layer 10 reaches the first region R1 and the second region R2 in a plan view from the z direction. Therefore, the resistance value of the storage element 100 is determined by the direction of magnetization of the first region R1, the second region R2, and the third region R3. On the other hand, as described above, the domain wall 27 does not easily penetrate into the first region R1 and the second region R2. That is, the first region R1 and the second region R2 in which the direction of magnetization is fixed have a great influence on the reference resistance of the data of “0” and “1” in the storage element 100, but the resistance change of the storage element 100 The effect on the third region R3 is smaller than that of the third region R3.

The resistance value of the memory element 100 decreases as the domain wall 27 approaches the first region R1, and increases as the domain wall 27 approaches the second region R2. As the area occupied by the first region R1 in the magnetic recording layer 20 increases, the minimum resistance value of the storage element 100 increases. Further, as the area occupied by the second region R2 in the magnetic recording layer 20 increases, the maximum resistance value of the storage element 100 decreases. In the storage element 100, the resistance change width can be made larger when the minimum resistance value is larger than when the maximum resistance value is smaller.

Hereinafter, a specific example will be described and described. First, as assumptions, no domain wall 27, the resistance value of the memory element 100 is shown in case the magnetization _{M 28} of the magnetization _{M 10} and the magnetic recording layer 20 of the first ferromagnetic layer 10 is completely parallel in the entire region 100 [Omega, the domain wall 27 without the resistance of the memory element 100 is shown in case the magnetization _{M 29} of the magnetization _{M 10} and the magnetic recording layer 20 of the first ferromagnetic layer 10 is completely antiparallel in the entire region and 200 [Omega. In this case, the storage element 100 has a resistance change width of 100Ω at the maximum. On the other hand, when the first region R1 and the second region R2 exist, the movement range of the domain wall 27 is limited to the third region R3, so that the magnetization M ₁₀ of the first ferromagnetic layer ₁₀ and the magnetic recording layer 20 Magnetizations M ₂₈ and M ₂₉ cannot be completely parallel or completely antiparallel. That is, the resistance change width of the storage element 100 is less than 100Ω.

First, as Comparative Example 1, the resistance change width of the storage element 100 when the first region R1 and the second region R2 each occupy 10% of each of the magnetic recording layer 20 is obtained. The storage element 100 shows the minimum resistance value when the domain wall 27 is at the boundary between the first region R1 and the third region R3, and when the domain wall 27 is at the boundary between the second region R2 and the third region R3. Shows the maximum resistance value. When the storage element 100 shows the minimum resistance value, 90% of the magnetization M ₂₈ of the magnetic recording layer 20 is parallel to the magnetization M ₁₀ of the first ferromagnetic layer 10, and 10% of the magnetization M ₂₉ of the magnetic recording layer 20 is the magnetization _{M 10} of the first ferromagnetic layer 10 become antiparallel. The minimum resistance value indicated by the storage element 100 is 105.3Ω. On the other hand, when the storage element 100 exhibits the maximum resistance value, the magnetization M ₂₈ of 10% of the magnetic recording layer 20 becomes parallel to the magnetization M ₁₀ of the first ferromagnetic layer 10, and the magnetization M ₂₈ of the magnetic recording layer 20 is 90%. M ₂₉ is antiparallel to the magnetization M ₁₀ of the first ferromagnetic layer 10. The maximum resistance value indicated by the storage element 100 is 181.8Ω. The resistance change width of the storage element 100 is 76.6Ω, and the MR ratio of the storage element 100 is 72.7.

Next, as Comparative Example 2, the resistance change width of the storage element 100 when the first region R1 occupies 5% of the magnetic recording layer 20 and the second region R2 occupies 15% of the magnetic recording layer 20 is determined. Ask. When the storage element 100 shows the minimum resistance value, 95% of the magnetization M ₂₈ of the magnetic recording layer 20 is parallel to the magnetization M ₁₀ of the first ferromagnetic layer 10, and 5% of the magnetization M ₂₉ of the magnetic recording layer 20 is the magnetization _{M 10} of the first ferromagnetic layer 10 become antiparallel. The minimum resistance value indicated by the storage element 100 is 102.6Ω. On the other hand, when the storage element 100 shows the maximum resistance value, the magnetization M ₂₈ of 15% of the magnetic recording layer 20 becomes parallel to the magnetization M ₁₀ of the first ferromagnetic layer 10, and the magnetization M ₂₈ of the magnetic recording layer 20 is 85%. M ₂₉ is antiparallel to the magnetization M ₁₀ of the first ferromagnetic layer 10. The maximum resistance value indicated by the storage element 100 is 173.9 Ω. The resistance change width of the storage element 100 is 71.3Ω, and the MR ratio of the storage element 100 is 69.6.

Finally, as Example 1, the resistance change width of the storage element 100 when the first region R1 occupies 15% of the magnetic recording layer 20 and the second region R2 occupies 5% of the magnetic recording layer 20. Ask for. When the storage element 100 shows the minimum resistance value, the magnetization M ₂₈ of 85% of the magnetic recording layer 20 is parallel to the magnetization M ₁₀ of the first ferromagnetic layer 10, and the magnetization M ₂₉ of 15% of the magnetic recording layer 20 is the magnetization _{M 10} of the first ferromagnetic layer 10 become antiparallel. The minimum resistance value indicated by the storage element 100 is 105.3Ω. On the other hand, when the storage element 100 exhibits the maximum resistance value, the 5% magnetization M ₂₈ of the magnetic recording layer 20 becomes parallel to the magnetization M ₁₀ of the first ferromagnetic layer 10, and 95% magnetization of the magnetic recording layer 20. M ₂₉ is antiparallel to the magnetization M ₁₀ of the first ferromagnetic layer 10. The maximum resistance value indicated by the storage element 100 is 190.5Ω. The resistance change width of the storage element 100 is 82.4Ω, and the MR ratio of the storage element 100 is 76.2.

As shown in Example 1, Comparative Example 1 and Comparative Example 2, when the ratio occupied by the first region R1 and the ratio occupied by the second region R2 in the magnetic recording layer 20 are varied, the resistance change width of the storage element 100 and the resistance change width The MR ratio fluctuates. In Example 1, since the ratio occupied by the first region R1 in the magnetic recording layer 20 is larger than the ratio occupied by the second region R2, the resistance change width and the MR ratio of the storage element 100 are larger than those of Comparative Example 1 and Comparative Example 2. .. This relationship is not limited to this example, and on the assumption that the ratio of the first region R1 in the magnetic recording layer 20 is larger than the ratio of the second region R2, the first region R1 and the second region R2 It does not change when the percentage occupied by is changed or when the value of the resistance value set as the precondition is changed.

That is, in the storage element 100 according to the first embodiment, since the area of the first portion R1a of the first region R1 is wider than the area of the second portion R2a of the second region R2, the width of the resistance change of the storage element 100 (dynamic). Range) is wide.

The storage element 100 can record data in analog instead of digital signals of "1" and "0". Therefore, the semiconductor device 200 functions as a neuromorphic device that imitates the brain.

The magnetization directions of the first ferromagnetic layer 10, the magnetic recording layer 20, and the first electrode 40 of the storage 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 making linearly polarized light incident on an object to be measured and using a magneto-optical effect (magnetic Kerr effect) in which rotation in the polarization direction occurs.

For example, the case of measuring the orientation direction of the magnetization of each of the first region R1, the second region R2, and the third region R3 of the magnetic recording layer 20 will be specifically described as an example. First, the storage element 100 is ground from the z direction to remove the first ferromagnetic layer 10. Since the non-magnetic layer 30 has a large influence on the orientation direction of the magnetization of the magnetic recording layer 20, a part of the non-magnetic layer 30 is left. Next, a magnetic field sufficient for the magnetizations M ₂₈ and M ₂₉ of the magnetic recording layer 20 to be oriented in one direction is applied in a predetermined direction. Then, the magnetization curve is measured while gradually reducing the applied magnetic field. The measurement point is the center position in the xy plane of each of the first region R1, the second region R2, and the third region R3. In the measured magnetization curve, the direction of magnetization can be specified by the positive or negative of the magnetization when the applied magnetic field first becomes zero. The directions of magnetization of the first ferromagnetic layer 10 and the first electrode 40 can also be measured in the same manner.

Although the preferred embodiment of the present invention has been described in detail above, the present invention is not limited to a specific embodiment, and various within the scope of the gist of the present invention described in the claims. Can be transformed / changed.

(First modification)
FIG. 4 is a schematic plan view of a first modification of the semiconductor device according to the first embodiment. The storage element 100A shown in FIG. 4 is different from the storage element 100 shown in FIG. 3 in that the first electrode 41 and the second electrode 51 have a circular shape in a plan view from the z direction. Other configurations are the same as those of the storage element 100 shown in FIG. 3, and the same reference numerals are given to the same configurations, and the description thereof will be omitted.

The magnetic recording layer 20 overlaps the first electrode 41 and the second electrode 51 in a plan view from the z direction. The area of the first portion R1a shown in FIG. 4 is larger than the area of the second portion R2a. In the example shown in FIG. 4, the maximum width w _{x1 in} the x direction of the portion where the first portion R1a and the magnetic recording layer 20 overlap is the maximum in the x direction of the portion where the second portion R2a and the magnetic recording layer 20 overlap. _Wider than width w _x2 . Also in the storage element 100A according to the first modification, since the area of the first portion R1a of the first region R1 is wider than the area of the second portion R2a of the second region R2, the width of the resistance change (dynamic range) of the storage element 100A. ) Is wide. The plan-view shapes of the first electrode 41 and the second electrode 51 from the z direction are not limited to the rectangle shown in FIG. 3 and the circle shown in FIG. 4, and various shapes can be selected.

(Second modification)
FIG. 5 is a schematic cross-sectional view of a second modification of the semiconductor device according to the first embodiment. The storage element 100B shown in FIG. 5 is different from the storage element 100 shown in FIG. 2 in that the second electrode 52 is a magnetic material. Other configurations are the same as those of the storage element 100 shown in FIG. 1, and the same reference numerals are given to the same configurations, and the description thereof will be omitted.

The second electrode 52 contains a magnetic material. The second electrode 52 has, for example, a unidirectionally oriented magnetization M ₅₂ . The orientation of the magnetization M ₅₂ of the second electrode 52 is the same as the orientation of the magnetization M ₁₀ of the first ferromagnetic layer 10, and is opposite to the orientation of the magnetization M ₄₀ of the first electrode 40. The magnetization M ₅₂ shown in FIG. 5 is oriented in the + z direction. The coercive force of the second electrode 52 is larger than the coercive force of the third region R3 of the magnetic recording layer 20.

The second electrode 52 can use the same structure and material as the first electrode 40. For example, the second electrode may have a synthetic antiferromagnetic structure.

Even in the storage element 100B according to the second modification, since the area of the first portion R1a of the first region R1 is wider than the area of the second portion R2a of the second region R2, the width of the resistance change (dynamic range) of the semiconductor device 100B. ) Is wide. Magnetization _{M 52} of the second electrode 52 fixes the magnetization of the second region R2 of the magnetic recording layer 20. By fixing the magnetization of the second region R2, it is possible to further suppress the invasion of the domain wall 27 into the second region R2.

(Third modification example)
FIG. 6 is a schematic cross-sectional view of a third modification of the storage element of the semiconductor device according to the first embodiment. FIG. 7 is a schematic plan view of a third modification of the storage element of the semiconductor device according to the first embodiment. FIG. 6 is a cross-sectional view of the storage element cut along the xz plane on the AA plane of FIG. The storage element 100C is different from the storage element 100 shown in FIG. 1 in that the shape of the side surface of the storage element in the x direction is different. Other configurations are the same as those of the storage element 100 shown in FIG. 1, and the same reference numerals are given to the same configurations, and the description thereof will be omitted.

The first ferromagnetic layer 11 has a magnetization M ₁₁ and has a first side surface 11S1 and a second side surface 11S2 in the x direction. The non-magnetic layer 31 has a first side surface 31S1 and a second side surface 31S2 in the x direction. The magnetic recording layer 21 has a first side surface 21S1 and a second side surface 21S2 in the x direction. The first side surfaces 11S1, 31S1, and 21S1 are the side surfaces of the first ferromagnetic layer 11, the non-magnetic layer 31, and the magnetic recording layer 21 which are close to the first electrode 43 among the two side surfaces in the x direction. The second side surfaces 11S2, 31S2, and 21S2 are the side surfaces of the first ferromagnetic layer 11, the non-magnetic layer 31, and the magnetic recording layer 21 which are close to the second electrode 53 among the two side surfaces in the x direction. The first side surfaces 11S1, 31S1, 21S1 and the second side surfaces 11S2, 31S2, 21S2 are inclined with respect to the z direction. The tangents of the first side surfaces 11S1, 31S1 and 21S1 have, for example, an inclination angle θ1 with respect to the z direction. The tangents of the second side surfaces 11S2, 31S2, 21S2 have, for example, an inclination angle θ2 with respect to the z direction. Further, the inclination angles θ1 and θ2 may be constant regardless of the position of the contact point for drawing the tangent line, or may be changed depending on the position of the contact point for drawing the tangent line. The inclination angles θ1 and θ2 shown in FIG. 6 change depending on the position where the tangent line is drawn.

The first electrode 43 has a magnetization M ₄₃ . The first electrode 43 has a first side surface 43S1 and a second side surface 43S2 in the x direction on a cut surface cut in the xz plane through the center of the magnetic recording layer 20 in the y direction. The second side surface 43S2 is located closer to the second electrode 53 than the first side surface 43S1. The first side surface 43S1 has a first inclined portion 43p1 and a second portion 43p2. The first inclined portion 43p1 is inclined with respect to the z direction. The tangent of the first inclined portion 43p1 has, for example, an inclination angle φ1 with respect to the z direction. The first inclined portion 43p1 has a larger inclination angle in the z direction than the second side surface 43S2. The first side surface 43S1 changes discontinuously at the boundary between the first inclined portion 43p1 and the second portion 43p2.

The first side surface 11S1, 31S1, 21S1 and the first inclined portion 43p1 are continuous. For example, in the XZ plane, when the first side surfaces 11S1, 31S1, 21S1 and the first inclined portion 43p1 can draw an asymptote with continuous straight lines or curves, it can be regarded as continuously changing.

The second electrode 53 has a first side surface 53S1 and a second side surface 53S2 in the x direction on a cut surface cut in the xz plane through the center of the magnetic recording layer 20 in the y direction. The second side surface 53S2 is located closer to the first electrode 43 than the first side surface 53S1. The first side surface 53S1 has a first inclined portion 53p1 and a second portion 53p2. The first inclined portion 53p1 is inclined with respect to the z direction. The tangent of the first inclined portion 53p1 has, for example, an inclination angle φ2 with respect to the z direction. The first inclined portion 53p1 has a larger inclination angle in the z direction than the second side surface 53S2. The first side surface 53S1 changes discontinuously at the boundary between the first inclined portion 53p1 and the second portion 53p2. The second side surface 11S2, 31S2, 21S2 and the first inclined portion 53p1 are continuous.

The first side surface 11S1, 31S1, 21S1, the second side surface 11S2, 31S2, 21S2 and the first inclined portions 43p1, 53p1 are formed by laminating the magnetic recording layer 20, the non-magnetic layer 30, and the first ferromagnetic layer 10 in this order. It is formed by removing a part of the end portion in the x direction of. The edges are processed by ion milling, photolithography, or the like. Magnetization generally has different values in regions where the state is different due to crystal grains, surface state, step, etching damage, etc., and affects each other. The part exposed after the x-direction end is removed is damaged. The damaged part may become a pinning site because the surface condition changes. The pinning site is the part where the magnetization becomes difficult to move. Pinning sites, whose magnetization becomes difficult to move due to damage, have the effect of affecting adjacent regions and fixing the magnetization more strongly. The first side surface 21S1 of the magnetic recording layer 20 serves as a pinning site and further fixes the magnetization of the first region R1. The first inclined portion 43p1 of the first electrode 43 serves as a pinning site and further fixes the magnetization M ₄₃ of the first electrode 43. The first side surface 21S1 of the magnetic recording layer 20 serves as a pinning site and further fixes the magnetization of the first region R1. The second side surface 21S2 of the magnetic recording layer 20 serves as a pinning site and further fixes the magnetization of the second region R2. That is, the magnetization of the first electrode 43, the first region R1 and the second region R2 is less likely to be inverted as compared with the case where the first inclined portion 43p1, the first side surface 21S and the second side surface 21S2 are not provided. By strengthening the fixation of the magnetization of the first region R1 and the second region R2 (the magnetization becomes difficult to reverse), the domain wall 27 becomes difficult to penetrate into the first region R1 and the second region R2.

Also in the storage element 100C according to the third modification, since the area of the first portion R1a of the first region R1 is wider than the area of the second portion R2a of the second region R2, the width of the resistance change (dynamic range) of the storage element 100C. ) Is wide.

In the third modification, the case where both side surfaces of the storage element 100C in the x direction are inclined is shown, but only one side surface may be inclined. Further, the second electrode 53 may include a magnetic material.

(Fourth modification)
FIG. 8 is a schematic cross-sectional view of a fourth modification of the storage element of the semiconductor device according to the first embodiment. In the storage element 100D shown in FIG. 8, the first side surfaces 11S1, 31S1, 21S1 and the first inclined portion 43p1 are discontinuous, and the second side surfaces 11S2, 31S2, 21S2 and the first inclined portion 53p1 are discontinuous. The point is different from the storage element 100C according to the third modification shown in FIG. Other configurations are the same as those of the storage element 100C according to the third modification shown in FIG. 8, and the same reference numerals are given to the same configurations, and the description thereof will be omitted.

Due to the difference in etching rate, the first side surfaces 11S1, 31S1, 21S1 and the first inclined portion 43p1 may be discontinuous. Similarly, the second side surface 11S2, 31S2, 21S2 and the first inclined portion 53p1 may be discontinuous.

Also in the storage element 100D according to the fourth modification, since the area of the first portion R1a of the first region R1 is wider than the area of the second portion R2a of the second region R2, the width of the resistance change (dynamic range) of the storage element 100D. ) Is wide.

Further, the first side surface 21S1, the second side surface 21S2, and the first inclined portion 43p1 of the magnetic recording layer 20 serve as pinning sites. By strengthening the fixation of the magnetization of the first region R1 and the second region R2 (the magnetization becomes difficult to reverse), the domain wall 27 becomes difficult to penetrate into the first region R1 and the second region R2.

Further, in the fourth modification, the case where both side surfaces of the storage element 100D in the x direction are inclined is shown, but only one side surface may be inclined. Further, the second electrode 53 may include a magnetic material.

(Fifth modification)
FIG. 9 is a schematic cross-sectional view of a fifth modification of the storage element according to the first embodiment. The memory element 100E shown in FIG. 9 has different shapes of the first electrode 44 and the second electrode 54 from the storage element 100C according to the third modification shown in FIG. Other configurations are the same as those of the storage element 100C according to the third modification shown in FIG. 6, and the same reference numerals are given to the same configurations, and the description thereof will be omitted.

The first electrode 44 has a magnetization M ₄₄ . The first electrode 44 has a first side surface 44S1 and a second side surface 44S2 in the x direction on a cut surface cut in the xz plane through the center of the magnetic recording layer 20 in the y direction. The second side surface 44S2 is located closer to the second electrode 54 than the first side surface 44S1. The first side surface 44S1 has a first inclined portion 44p1 and a second inclined portion 44p2. The first inclined portion 44p1 and the second inclined portion 44p2 are inclined with respect to the z direction. The tangent line of the first inclined portion 44p1 has, for example, an inclination angle φ3 with respect to the z direction. The tangent of the second inclined portion 44p2 has, for example, an inclination angle φ4 with respect to the z direction. The first inclined portion 44p1 has a larger inclination angle in the z direction than the second side surface 44S2. The first side surface 44S1 changes discontinuously at the boundary between the first inclined portion 44p1 and the second inclined portion 44p2.

The second electrode 54 has a first side surface 54S1 and a second side surface 54S2 in the x direction on a cut surface cut in the xz plane. The second side surface 54S2 is located closer to the first electrode 44 than the first side surface 54S1. The first side surface 54S1 has a first inclined portion 54p1 and a second inclined portion 54p2. The first inclined portion 54p1 and the second inclined portion 54p2 are inclined with respect to the z direction. The tangent line of the first inclined portion 54p1 has, for example, an inclination angle φ5 with respect to the z direction. The tangent line of the second inclined portion 54p2 has, for example, an inclination angle φ6 with respect to the z direction. The first inclined portion 54p1 has a larger inclination angle in the z direction than the second side surface 54S2. The first side surface 54S1 changes discontinuously at the boundary between the first inclined portion 54p1 and the second inclined portion 54p2.

Also in the storage element 100E according to the fifth modification, since the area of the first portion R1a of the first region R1 is wider than the area of the second portion R2a of the second region R2, the width of the resistance change (dynamic range) of the storage element 100E. ) Is wide.

Further, the first side surface 21S1, the second side surface 21S2, and the first inclined portion 44p1 of the magnetic recording layer 20 serve as pinning sites. By strengthening the fixation of the magnetization of the first region R1 and the second region R2 (the magnetization is less likely to be reversed), it becomes difficult for the domain wall 27 to invade the first region R1 and the second region R2.

Further, in the fifth modification, the case where both side surfaces of the storage element 100E in the x direction are inclined is shown, but only one side surface may be inclined. The shape of the first electrode 44 and the second electrode 54 on the xz cut surface is not limited to a trapezoid in which the length of the upper base in the + z direction is shorter than the length of the lower base in the −z direction, and the length of the upper base in the + z direction. May be a trapezoid longer than the length of the lower base in the −z direction. Further, the second electrode 54 may contain a magnetic material.

[Second Embodiment]
FIG. 10 is a schematic cross-sectional view of the semiconductor device according to the second embodiment. The semiconductor device 201 shown in FIG. 10 is different from the semiconductor device 200 according to the first embodiment in that the first ferromagnetic layer 10 has a bottom pin structure located closer to the substrate 60 than the magnetic recording layer 20. Other configurations are the same as those of the semiconductor device 200 shown in FIG. 1, and the same reference numerals are given to the same configurations, and the description thereof will be omitted.

FIG. 11 is a schematic cross-sectional view of the storage element of the semiconductor device according to the second embodiment. The semiconductor device 101 has a first ferromagnetic layer 10, a magnetic recording layer 20, a non-magnetic layer 30, a first electrode 40, and a second electrode 50. An insulating layer 81 is provided between the first electrode 40 and the second electrode 50.

As the insulating layer 81, the same one as that of the insulating layer 80 in the first embodiment is used. The insulating layer 81 is formed on the surface of the magnetic recording layer 20 opposite to the surface on the non-magnetic layer 30 side. The insulating layer 81 covers the third region R3 of the magnetic recording layer 20. The insulating layer 81 also functions as a cap layer. The cap layer is a layer for enhancing the orientation of the magnetization of the magnetic recording layer 20 and protecting the magnetic recording layer 20. Since the cap layer is an insulator, it is possible to prevent the current for driving the domain wall 27 from being diverted to the insulating layer 81 side.

The semiconductor device 101 having a bottom pin structure is manufactured by the following procedure. First, the first transistor Tr1, the second transistor Tr2, the third transistor Tr3, the first wiring Cm, the second wiring Wp, and the third wiring Rp are formed on the substrate 60 via the insulating layer 80. Then, the first ferromagnetic layer 10, the non-magnetic layer 30, and the magnetic recording layer 20 are laminated in this order on one surface of the insulating layer 80, and each layer is processed into a predetermined shape. Then, the periphery of the first ferromagnetic layer 10, the non-magnetic layer 30, and the magnetic recording layer 20 is further covered with an insulating layer 80. After flattening the surfaces of the magnetic recording layer 20 and the insulating layer 80, the first electrode 40 and the second electrode 50 are formed. Then, the semiconductor device 201 is obtained by filling the space between the first electrode 40 and the second electrode 50 with the insulating layer 81.

Also in the storage element 101 according to the second embodiment, since the area of the first portion R1a of the first region R1 is wider than the area of the second portion R2a of the second region R2, the width of the resistance change (dynamic range) of the storage element 101. ) Is wide.

The storage element 101 according to the second embodiment can select a modification similar to the storage element 100 according to the first embodiment.

(6th modification)
FIG. 12 is a schematic cross-sectional view of a sixth modification of the storage element according to the second embodiment. The storage element 101B shown in FIG. 12 has the shapes of the first electrode 45 and the second electrode 55, the shapes of the first portion R1a'and the second portion R2a'of the domain wall moving layer 20, and the first electrode 45 and the second electrode. The relationship between the 55 and the insulating layer 81 is different from that of the storage element 101 according to the second embodiment shown in FIG. Other configurations are the same as those of the storage element 101 according to the second embodiment shown in FIG. 11, and the same reference numerals are given to the same configurations, and the description thereof will be omitted.

The first region R1 of the domain wall moving layer 20 has a first portion R1a'. The first portion R1a'is a surface facing the first electrode 45 in the first region R1. The first portion R1a'is, for example, a surface in contact with the first electrode 45 in the first region R1. The second region R2 of the domain wall moving layer 20 has a second portion R2a'. The second portion R2a'is a surface facing the second electrode 50 in the second region R2. The second portion R2a'is, for example, a surface in contact with the second electrode 55 in the second region R2. The area of the first portion R1a'is larger than the area of the second portion R2a'. The first portion R1a'and the second portion R2a' are inclined in the x direction with respect to the z direction. The first surface 20a, the first portion R1a'and the second portion R2a', which are the surfaces of the domain wall moving layer 20 in the z direction, are discontinuous. The first portion R1a'and the second portion R2a'are formed by milling a part of the domain wall moving layer 20 when a part of the insulating layer 81 is removed.

Further, the first portion R1a'and the second portion R2a'of the magnetic recording layer 20 serve as pinning sites. By strengthening the fixation of the magnetization of the first region R1 and the second region R2 (the magnetization is less likely to be reversed), it becomes difficult for the domain wall 27 to invade the first region R1 and the second region R2.

The surfaces 45a and 55a of the first electrode 45 and the second electrode 55 have an arcuate convex shape on a cut surface cut in the xz plane passing through the center of the magnetic recording layer 20 in the y direction. The surfaces of the first electrode 45 and the second electrode 55 may be formed in an arc shape due to surface tension.

The surface 81a of the insulating layer 81 is located in the −z direction from at least a part of the surfaces 45a and 55a of the first electrode 45 and the second electrode 55. The two side surfaces 81S1 and 81S2 of the insulating layer 81 in the x direction are inclined in the x direction with respect to the z direction. The side surfaces 81S1 and 81S2 are formed by milling.

Also in the storage element 101B according to the sixth modification, since the area of the first portion R1a'of the first region R1 is wider than the area of the second portion R2a'of the second region R2, the width of the resistance change of the storage element 101B ( Dynamic range) is wide.

[Third Embodiment]
FIG. 13 is a block diagram of the magnetic recording array according to the third embodiment. The magnetic recording array 300 includes a storage element 100, a first wiring Cm1 to Cmn, a second wiring Wp1 to Wpn, a third wiring Rp1 to Rpn, a first switching element 110, a second switching element 120, and a second. It includes 3 switching elements 130. The first wiring Cm shown in FIG. 1 is one of the first wirings Cm1 to Cmn shown in FIG. The second wiring Wp shown in FIG. 1 is one of the second wirings Wp1 to Wpn shown in FIG. The third wiring Rp shown in FIG. 1 is one of the third wirings Rp1 to Rpn shown in FIG. The first switching element 110 is, for example, the third transistor Tr3 shown in FIG. The second switching element 120 is, for example, the first transistor Tr1 shown in FIG. The third switching element 130 is, for example, the second transistor Tr2 shown in FIG. Further, the storage element 100 is not limited to the one shown in FIG. 1, and may have other modifications or configurations of other embodiments.

<1st wiring, 2nd wiring, 3rd wiring>
The first wirings Cm1 to Cmn are common wirings. The common wiring is wiring used both when writing data and when reading data. The first wirings Cm1 to Cmn are electrically connected to the reference potential. For example, when the first wirings Cm1 to Cmn are grounded, the reference potential is ground. Further, the first wirings Cm1 to Cmn are connected to at least one storage element 100 among the plurality of storage elements 100. The first wirings Cm1 to Cmn may be provided in each of the plurality of storage elements 100, or may be provided over the plurality of storage elements 100.

The second wirings Wp1 to Wpn are write wirings. The second wirings Wp1 to Wpn are electrically connected to at least two or more storage elements 100 among the plurality of storage elements 100. The second wirings Wp1 to Wpn are connected to the power supply when the magnetic recording array 300 is used.

The third wirings Rp1 to Rpn are read wirings. The third wirings Rp1 to Rpn are electrically connected to at least one or more storage elements 100 among the plurality of storage elements 100. The third wirings Rp1 to Rpn are connected to a power source when the magnetic recording array 300 is used.

<1st switching element, 2nd switching element, 3rd switching element>
The first switching element 110 is connected between each of the storage elements 100 and the first wirings Cm1 to Cmn. The second switching element 120 is connected between each of the storage elements 100 and the second wirings Wp1 to Wpn. The third switching element 130 is connected between each of the storage elements 100 and the third wirings Rp1 to Rpn.

When the first switching element 110 and the second switching element 120 are turned on, a write current flows between the first wirings Cm1 to Cmn and the second wirings Wp1 to Wpn connected to the predetermined storage element 100. When the first switching element 110 and the third switching element 130 are turned on, a read current flows between the first wirings Cm1 to Cmn and the third wirings Rp1 to Rpn connected to the predetermined storage element 100.

The first switching element 110, the second switching element 120, and the third switching element 130 are elements that control the flow of current. For example, as the first switching element 110, the second switching element 120, and the third switching element 130, a transistor, an Ovonic Threshold Switch (OTS) that utilizes a phase change of a crystal layer, a metal insulator transition, etc. A switch that utilizes a change in band structure such as a (MIT) switch, a switch that utilizes a breakdown voltage such as a Zener diode and an avalanche diode, and a switch whose conductivity changes as the atomic position changes can be used.

The second switching element 120 and the third switching element 130 may be shared by the storage elements 100 connected to one second wiring Wp1 to Wpn or one third wiring Rp1 to Rpn. For example, one second switching element 120 may be provided on the upstream side of any second wiring Wpn. Further, for example, one third switching element 130 may be provided on the upstream side of any third wiring Rpn. A specific storage element 100 can be selected by switching ON / OFF of the first switching element 110 connected to each storage element 100.

A plurality of storage elements 100 are integrated in the magnetic recording array 300. The width (dynamic range) of the resistance change of each storage element 100 is wide. Therefore, the influence of noise on the data recorded by each storage element 100 is suppressed, and the reliability of the data of the magnetic recording array 300 is further enhanced.

10, 11 First ferromagnetic layers 20, 21 Magnetic recording layer 27 Magnetic wall 28 First magnetic domain 29 Second magnetic domain 30, 31 Non-magnetic layers 40, 41, 43, 44, 45 First electrodes 50, 51, 52, 53, 54, 55 Second electrode 60 Substrate 70 Interlayer insulation film 80 Insulation layer 100, 100A, 100B, 100C, 100D, 100E, 101 Semiconductor device 110 First switching element 120 Second switching element 130 Third switching element 200 Magnetic recording array 20a , 40a, 50a, 60a 1st surface 20b 2nd surface 11S1, 21S1, 31S1, 43S1, 44S1, 53S1, 54S1 1st side surface 11S2, 21S2, 31S2, 43S2, 44S2, 53S2, 54S2 2nd surface 43p1, 44p1, 53p1 , 54p1 1st inclined part 43p2, 53p2 2nd part 44p2, 54p2 2nd inclined part R1 1st region R1a, R1a'1st part R2a, R2a' 2nd part R2 2nd region R3 3rd region M ₁₀ , M ₁₁ , M ₂₈ , M ₂₉ , M ₄₀ , M ₄₃ , M ₄₄ , M ₅₂ Magnetized Cm1 to Cmn 1st wiring Wp1 to Wpn 2nd wiring Rp1 to Rpn 3rd wiring

Claims (10)

The first ferromagnetic layer and
A magnetic recording layer located in the first direction with respect to the first ferromagnetic layer and extending in the second direction,
A non-magnetic layer located between the first ferromagnetic layer and the magnetic recording layer,
A first electrode and a second electrode located on the opposite side of the magnetic recording layer to the non-magnetic layer and overlapping a part of the magnetic recording layer in the first direction are provided.
The first electrode contains a magnetic material whose magnetization is oriented in a direction different from the magnetization direction of the first ferromagnetic layer.
The magnetic recording layer has a first region that overlaps the first electrode and the first ferromagnetic layer in the first direction, and a second region that overlaps the second electrode and the first ferromagnetic layer in the first direction. And a third region sandwiched between the first region and the second region.
The area of the first portion of the first region facing the first electrode is larger than the area of the second portion of the second region facing the second electrode.
The first ferromagnetic layer is a domain wall moving element that overlaps the first electrode and a part of the second electrode in the first direction. The domain wall moving element according to claim 1, wherein the second electrode contains a magnetic material whose magnetization is oriented in the same direction as the magnetization of the first ferromagnetic layer. Has more boards,
The domain wall moving element according to claim 1 or 2, wherein the first ferromagnetic layer is located closer to the substrate than the magnetic recording layer. The domain wall moving element according to claim 3, further comprising an insulating layer covering the third region of the magnetic recording layer. Has more boards,
The domain wall moving element according to any one of claims 1 to 4, wherein the first ferromagnetic layer is located at a position farther from the substrate than the magnetic recording layer. The magnetic wall moving element according to claim 5, wherein the side surface of the magnetic recording layer in the second direction is inclined with respect to the first direction. The domain wall moving element according to claim 5 or 6, wherein the first electrode has a first inclined portion that is inclined with respect to the first direction. In a cut surface extending in the first direction and the second direction through the center of the first direction and the third direction orthogonal to the second direction of the magnetic recording layer.
The first electrode has a first side surface and a second side surface located closer to the second electrode than the first side surface.
The magnetic wall moving element according to any one of claims 5 to 7, wherein the first side surface has a portion having an inclination angle larger than the inclination angle of the second side surface with respect to the first direction. In a cut surface extending in the first direction and the second direction through the center of the first direction and the third direction orthogonal to the second direction of the magnetic recording layer.
The first electrode has a first side surface and a second side surface located closer to the second electrode than the first side surface.
The domain wall moving element according to any one of claims 5 to 8, wherein the first side surface has a portion in which the inclination with respect to the first direction changes discontinuously. A magnetic recording array having a plurality of domain wall moving elements according to any one of claims 1 to 9.

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