WO2021153853A1

WO2021153853A1 - Magnetic domain wall logic device and manufacturing method therefor

Info

Publication number: WO2021153853A1
Application number: PCT/KR2020/006967
Authority: WO
Inventors: 김갑진; 이근희
Original assignee: 한국과학기술원
Priority date: 2020-01-31
Filing date: 2020-05-29
Publication date: 2021-08-05
Also published as: KR20210098098A; KR102342962B1; KR102342919B1; KR20210119941A

Abstract

Disclosed is a magnetic domain wall logic device comprising: a nonmagnetic layer; and a magnetic layer formed on the nonmagnetic layer. The magnetic layer comprises: a perpendicular magnetic anisotropy region; and a horizontal magnetic anisotropy region adjacent to the perpendicular magnetic anisotropy region. The magnetic domain wall logic device is operated by an in-plane current of the nonmagnetic layer. The magnetic domain wall logic device, which is provided according to an aspect of the present invention, is a logic device which can be implemented by only moving a magnetic domain wall, enables current driving, and has a simple structure. In addition, when the logic device is used, the data processing speed can be improved.

Description

Magnetic domain wall logic device and manufacturing method thereof

The present invention relates to a magnetic domain wall logic device and a method for manufacturing the same.

Big data, artificial intelligence, and machine learning-related technologies have recently received a lot of attention. What these three fields have in common is that they must be able to access and process large amounts of data in order to derive meaningful results. Therefore, for high-quality research related to big data, artificial intelligence, and machine learning, research on data access speed and processing speed improvement technologies is also needed. Currently, data processing consists of storing data in a mass storage device such as a Hard Disk Drive (HDD)/Solid State Drive (SSD), loading data into Random Access Memory (RAM), and processing it with a processor. At this time, the processing speed of the processor is only 1 ns (10 ^-9 s), but it is known that it takes ^{1 ms (10 -3} s) to load data from HDD or SSD. As such, the difference in processor processing speed and data access speed causes a bottleneck in data processing speed, which is called the von Neumann bottleneck.

Semiconductor-based memories inherently have disadvantages in that it is difficult to store the memory without an external power source and the material price is high. On the other hand, HDD, which is a typical magnetic memory, is inexpensive and has the advantage of being able to store data semi-permanently without an external power source if there is no external magnetic field. However, HDD has the disadvantage of high power consumption and slow speed because it has to rotate the disk and move the reading head. To compensate for these shortcomings, a new magnetic memory has been proposed, one is Magnetoresistive RAM (MRAM) and the other is Racetrack memory.

Even if a magnetic memory with good performance is used, if data is uploaded to a transistor-based processor, performance will deteriorate due to a von Neumann bottleneck. Accordingly, a processor compatible with the magnetic memory is required, and the need for logic operation using magnetic domains and magnetic domain walls has emerged. It is not that such attempts have not been made in the past. Because logic devices using existing magnetic domain walls have a complex structure and are driven using a magnetic field, problems arise when integrating devices on a ^{nanometer (nm = 10 -9 m) scale.} is likely to occur

For example, D. A. Allwood, et al., Science 309, 1688 (2005) discloses a logic device using magnetic domain wall movement. However, the logic device in this paper has a very complex structure, the device must be driven by a magnetic field, and the magnetization direction is parallel to the plane. These features have limitations in making it difficult to fabricate nano-processing devices.

Therefore, there is a need for a magnetic domain wall-based logic device that can be driven using current and has a simple structure.

[Patent Literature]

(Patent Document 1) Republic of Korea Patent Publication No. 10-2016-0136282

[Non-patent literature]

(Non-Patent Document 1) D. A. Allwood, et al., Science 309, 1688 (2005), "Magnetic Domain-Wall Logic"

SUMMARY OF THE INVENTION An object of the present invention is to provide a magnetic domain wall-based logic device that can be driven using a current and has a simple structure.

In order to achieve the above object, in one aspect of the present invention

non-magnetic layer; and

A magnetic domain wall logic device comprising a magnetic layer formed on the non-magnetic layer,

The magnetic layer is

perpendicular magnetic anisotropy region; and

a horizontal magnetic anisotropy region adjacent to the perpendicular magnetic anisotropy region;

includes,

The magnetic domain wall logic device is provided, characterized in that it is operated by the in-plane current of the non-magnetic layer.

As an embodiment of the magnetic domain wall logic element,

non-magnetic layer; and

The magnetic layer is

a first perpendicular magnetic anisotropy region and a second perpendicular magnetic anisotropy region; and

a horizontal magnetic anisotropy region positioned between the first perpendicular magnetic anisotropy region and the second perpendicular magnetic anisotropy region;

including,

The NOT element is provided with a NOT element characterized in that it is operated by the in-plane current of the non-magnetic layer.

In addition, as an embodiment of the magnetic domain wall logic element,

non-magnetic layer; and

The magnetic layer is

a first horizontal magnetic anisotropy region and a second horizontal magnetic anisotropy region; and

a perpendicular magnetic anisotropy region positioned between the first horizontal magnetic anisotropy region and the second horizontal magnetic anisotropy region;

including,

As another embodiment of the magnetic domain wall logic element,

non-magnetic layer; and

The magnetic layer is

magnetic symmetry breaking region;

a first horizontal magnetic anisotropy region and a first perpendicular magnetic anisotropy region sequentially extending in a first direction from the magnetic symmetry breaking region;

a second horizontal magnetic anisotropy region and a second perpendicular magnetic anisotropy region sequentially extending in a second direction from the magnetic symmetry breaking region; and

a third perpendicular magnetic anisotropy region extending in a third direction from the magnetic symmetry breaking region;

including,

There is provided a logic element characterized in that the logic element is operated by the in-plane current of the non-magnetic layer.

Here, the logic device may be a NAND device or a NOR device.

As another embodiment of the magnetic domain wall logic element,

non-magnetic layer; and

The magnetic layer is

magnetic symmetry breaking region;

a first perpendicular magnetic anisotropy region and a first horizontal magnetic anisotropy region sequentially extending in a first direction from the magnetic symmetry breaking region;

a second perpendicular magnetic anisotropy region and a second horizontal magnetic anisotropy region sequentially extending in a second direction from the magnetic symmetry breaking region; and

a third horizontal magnetic anisotropy region extending in a third direction from the magnetic symmetry breaking region;

including,

In addition, in another aspect of the present invention

In the magnetic domain wall logic device manufacturing method,

forming a perpendicular magnetic anisotropy region and a horizontal magnetic anisotropy region in a magnetic layer having a complex structure including a non-magnetic layer and a magnetic layer formed on the non-magnetic layer;

There is provided a method for manufacturing a magnetic domain wall logic device comprising:

As an embodiment of the method for manufacturing the magnetic domain wall logic device,

In the NOT element manufacturing method,

There is provided a NOT device manufacturing method comprising a.

In addition, as another embodiment of the method for manufacturing the magnetic domain wall logic device,

In the method of manufacturing the logic device,

A third perpendicular magnetic anisotropy region in a magnetic layer having a composite structure including a non-magnetic layer and a magnetic layer formed on the non-magnetic layer, and a first horizontal magnetic anisotropy sequentially extending in a first direction from a first portion of the third perpendicular magnetic anisotropy region forming a region and a first perpendicular magnetic anisotropy region, a second horizontal magnetic anisotropy region and a second perpendicular magnetic anisotropy region sequentially extending in a second direction from a first portion of the third perpendicular magnetic anisotropy region; and

forming a magnetic symmetry breaking region by breaking magnetic symmetry by applying a magnetic field to a first portion of the third perpendicular magnetic anisotropy region;

There is provided a method of manufacturing a logic device comprising a.

Here, the logic device may be a NAND device or a NOR device.

The magnetic domain wall logic device provided in one aspect of the present invention has the advantage that the logic device can be implemented only by moving the domain wall, can be driven by current, and has a simple structure. In addition, when such a logic element is used, there is an effect of improving the data processing speed.

1a and 1b schematically show a logic device according to an embodiment of the present invention,

2 shows a magnetic material having perpendicular magnetic anisotropy and horizontal magnetic anisotropy;

3 schematically shows the Dzyaloshinskii-Moriya interaction in a composite structure of a magnetic layer and a non-magnetic layer according to an embodiment of the present invention;

4 schematically shows the magnetization direction according to the Dzyaloshinskii-Moriya interaction when the perpendicular magnetic anisotropy region and the horizontal magnetic anisotropy region are generated according to an embodiment of the present invention.

5 schematically shows whether the magnetization direction is stable in consideration of the Dzyaloshinskii-Moriya interaction;

6 schematically shows a spin current formed by an in-plane current of a non-magnetic layer in a composite structure according to an embodiment of the present invention;

7 schematically shows the movement of the magnetic domain wall by the spin current formed by the in-plane current of the non-magnetic layer in the composite structure according to an embodiment of the present invention;

8 shows the result of the NOT element according to an embodiment of the present invention implemented through computational simulation,

9 schematically shows a change in the magnetization direction in the operation process of the NOT element according to an embodiment of the present invention;

10 schematically shows a NAND device or a NOT device according to an embodiment of the present invention;

11 shows a current density distribution of a NAND device or a NOT device according to an embodiment of the present invention;

12 shows a result of implementing a NAND device according to an embodiment of the present invention through computational simulation;

13 shows the results of the NOR device according to an embodiment of the present invention implemented through computational simulation,

14 is a diagram illustrating a magnetization direction in a self-symmetry breakdown region according to a magnetization direction at each input in a NAND or NOR device according to an embodiment of the present invention.

Since the present invention can make various changes and thus various embodiments can be made, specific embodiments will be presented below and described in detail.

In addition, all terms in this specification that are not specifically defined may be used in a meaning that is understandable to all those of ordinary skill in the art to which the present invention belongs.

However, it should be understood that the present invention is not intended to be limited only to the specific embodiments to be described below, and includes all modifications, equivalents and substitutes included in the spirit and scope of the present invention.

Accordingly, there may be other equivalents and modifications to the embodiments described herein, and the embodiments presented herein are only the most preferred embodiments.

Adjacent as used herein includes all that are in contact with or include another space therebetween.

In one aspect of the invention

non-magnetic layer; and

The magnetic layer is

perpendicular magnetic anisotropy region; and

includes,

Hereinafter, the magnetic domain wall logic element provided in one aspect of the present invention will be described in detail for each configuration.

First, the magnetic domain wall logic device provided in one aspect of the present invention includes a non-magnetic layer.

The non-magnetic layer may include at least one selected from the group consisting of a non-magnetic metal and a topological insulator.

The non-magnetic metal may be, for example, platinum (Pt), palladium (Pd), tantalum (Ta), titanium (Ti), tungsten (W), or gold (Au), but is not limited thereto.

The topological insulator may be, for example, Bi ₂ Se ₃ , Bi ₂ Te _{3 ,} and Ag ₂ Te ₃ , but is not limited thereto.

When the phase insulator is used as the nonmagnetic layer, a strong spin current can be generated even with a low current, which is preferable in that the driving threshold current density can be reduced.

Next, the magnetic domain wall logic device provided in one aspect of the present invention includes a magnetic layer.

The magnetic layer may be formed on the non-magnetic layer.

Preferably, the magnetic layer and the non-magnetic layer may extend side by side in contact with each other.

The magnetic layer may include at least one selected from the group consisting of a ferromagnetic material and a ferrimagnetic material.

The ferromagnetic material includes both metals and non-metals, conductors and insulators, and may be, for example, cobalt (Co), iron (Fe), nickel (Ni), and alloys thereof, but is not limited thereto.

The ferrimagnetic material includes both metals and non-metals, conductors and insulators, for example, TbCo, TbFe, GdCo, GdFe, GdFeCo, Fe ₃ O ₄ , YIG (Yttrium iron garnet), TmIG, TbIG, etc., but may be It is not limited.

When the ferrimagnetic material is used, it is preferable in that the critical current density is reduced due to low magnetization, the magnetization dynamic speed can be increased at the angular momentum compensation point, and thus the driving time of the logic device can be reduced.

The thickness of the magnetic layer may be 0.1 nm to 10 nm. Preferably it may be 0.2 nm to 5 nm, more preferably 0.3 nm to 3 nm.

When the thickness of the magnetic layer exceeds 10 nm, there is a problem that the size of the effective magnetic field caused by the spin flow is relatively small and the driving threshold current density may be high. there is.

The magnetic layer may include a perpendicular magnetic anisotropy region and a horizontal magnetic anisotropy region adjacent to the perpendicular magnetic anisotropy region.

The perpendicular magnetic anisotropy region refers to a region having magnetic anisotropy in a vertical direction, and the horizontal magnetic anisotropy region refers to a region having magnetic anisotropy in a horizontal direction. This can be understood with reference to FIG. 2 .

The perpendicular magnetic anisotropy region and the horizontal magnetic anisotropy region may be disposed adjacent to each other in an in-plane direction of the magnetic layer.

Preferably, the perpendicular magnetic anisotropy region and the horizontal magnetic anisotropy region may be in contact with each other.

The number of the perpendicular magnetic anisotropy region and the horizontal magnetic anisotropy region may each be one or more, but is not limited to a specific number.

The magnetic domain wall logic element may be operated by an in-plane current of the non-magnetic layer.

For example, when a magnetization region having a magnetization opposite to the aligned magnetization direction is input, a magnetic domain wall may be generated at the boundary thereof.

Such a magnetic domain wall may move by an in-plane current of the non-magnetic layer. The in-plane current and the moving direction of the magnetic domain wall may be parallel or anti-parallel.

In the composite structure in which the non-magnetic layer and the magnetic layer are bonded, when an in-plane current flows through the non-magnetic layer, conduction electrons of the non-magnetic layer interact with electrons that generate magnetization of the magnetic layer to exchange angular momentum.

That is, the magnetic domain wall may move due to the spin-orbit torque (SOT) principle. This can be understood with reference to FIGS. 6 and 7 .

If the magnetization region in the same direction as the aligned direction is input, a separate magnetic domain wall is not formed, and thus the magnetic domain wall may not move. However, even in this case, a desired value is output as an output value, so there is no problem in operating as a logic element.

In addition, in the composite structure in which the non-magnetic layer and the magnetic layer are bonded, neighboring spindles having a specific angle may be energetically stable due to Dzyaloshinskii-Moriya interaction (DMI).

Accordingly, when the perpendicular magnetic anisotropy region and the horizontal magnetic anisotropy region are adjacent to each other in the magnetic layer, magnetization in a specific direction may be energetically favored. This can be understood with reference to FIGS. 3 to 5 .

In addition, the magnetic domain wall logic device provided in one aspect of the present invention may further include an oxide layer.

The oxide layer may be formed on the magnetic layer.

The oxide layer may be, for example, at _{least one selected from the group consisting of MgO, AlO x} , SiO _x and SiN, but is not limited thereto.

When the magnetic domain wall logic element further includes an oxide layer, it is preferable in that the perpendicular magnetic anisotropy can be enhanced or controlled.

The magnetic domain wall logic device provided in one aspect of the present invention may be, for example, a NOT device, a NOR device, or a NAND device, but is not limited thereto.

As an embodiment of the magnetic domain wall logic element,

non-magnetic layer; and

The magnetic layer is

including,

Hereinafter, the NOT element will be described in detail for each configuration.

A NOT device according to an embodiment of the present invention includes a non-magnetic layer and a magnetic layer formed on the non-magnetic layer.

The above-described contents may be applied to the material, thickness, arrangement, behavior, etc. of the non-magnetic layer and the magnetic layer, and this will not be repeated.

The magnetic layer includes a first perpendicular magnetic anisotropy region and a second perpendicular magnetic anisotropy region, and a horizontal magnetic anisotropy region between the first perpendicular magnetic anisotropy region and the second perpendicular magnetic anisotropy region.

The first perpendicular magnetic anisotropy region, the horizontal magnetic anisotropy region, and the second perpendicular magnetic anisotropy region may be sequentially adjacent to each other in an in-plane direction.

That is, the first perpendicular magnetic anisotropy region, the horizontal magnetic anisotropy region, and the second perpendicular magnetic anisotropy region are arranged in order.

Preferably, the first perpendicular magnetic anisotropy region and the second perpendicular magnetic anisotropy region may be in contact with the horizontal magnetic anisotropy region.

The first perpendicular magnetic anisotropy region and the second perpendicular magnetic anisotropy region may have magnetization directions opposite to each other.

That is, as described above, the spin of the neighboring region may be energetically stable if the neighboring spins have a specific angle. For example, if it is assumed that the spindles arranged from left to right as shown in FIG. 5 are stable when they are arranged to rotate in a counterclockwise direction, they may be unstable when they are arranged to rotate in a clockwise direction.

In this case, when the first perpendicular magnetic anisotropy region, the horizontal magnetic anisotropy region, and the second perpendicular magnetic anisotropy region are arranged adjacent to each other in order as shown in FIG. 9, when the first perpendicular magnetic anisotropy region has an upward spin, horizontal The magnetic anisotropy region may be arranged such that the spindle rotates counterclockwise from left to right. Accordingly, the second perpendicular magnetic anisotropy region has a downward magnetization direction.

On the other hand, when the first perpendicular magnetic anisotropy region has a downward magnetization direction, the horizontal magnetic anisotropy region is arranged such that the spindle rotates counterclockwise from left to right, and accordingly, the second perpendicular magnetic anisotropy region is upward direction of magnetization.

Accordingly, for example, when a magnetization region in a specific direction, which is an input value, is input to the first perpendicular magnetic anisotropy region, a magnetization region in the opposite direction is output to the second perpendicular magnetic anisotropy region, which can function as a NOT element. there is.

The length of the horizontal magnetic anisotropy region may be a value satisfying Equation 1 below, and may vary depending on the exchange bonding strength of the magnetic material and the magnitude of the Dzyaloshinskii-Moriya interaction. More specifically, it may be 10 nm to 10 μm.

Here, l _π is the length of the horizontal magnetic anisotropy region, A is the exchange stiffness, and D is the DMI strength.

That is, many interactions affect the microstructure of the spin arrangement. Among them, the Heisenberg type exchange interaction has low energy when two adjacent spins have an angle of 0 degrees, and DMI shows that two adjacent spins have an angle of 90 degrees. Since it is known that it has low energy when it has , if both interactions are taken into account at the same time, the length of the horizontal magnetic anisotropy region in which the spin arrangement twisted by 180 degrees can be stable can be inferred as in Equation 1 above.

The NOT element may be operated by an in-plane current of the non-magnetic layer.

For example, when a magnetization region opposite to the aligned direction is input to the NOT element, a magnetic domain wall may be generated at the boundary.

If the magnetization region in the same direction as the aligned direction is input, a separate magnetic domain wall is not formed, and thus the magnetic domain wall may not move. However, even in this case, since a desired value is output as an output value, there is no problem in operating as a NOT element.

In the NOT element, the first perpendicular magnetic anisotropy region may be an input terminal, and the second perpendicular magnetic anisotropy region may be an output terminal, but is not limited thereto.

As an embodiment of the magnetic domain wall logic element, the NOT element may further include a first horizontal magnetic anisotropy region and a second horizontal magnetic anisotropy region; and a perpendicular magnetic anisotropy region positioned between the first horizontal magnetic anisotropy region and the second horizontal magnetic anisotropy region.

In this case, the first horizontal magnetic anisotropy region and the second horizontal magnetic anisotropy region may be an input terminal and an output terminal, respectively.

However, when the first horizontal magnetic anisotropy region is positioned between the first perpendicular magnetic anisotropy region and the second perpendicular magnetic anisotropy region, and the first perpendicular magnetic anisotropy region and the second perpendicular magnetic anisotropy region are input terminals and output terminals, respectively, the device It may be more preferable in terms of directness.

In more detail, the normal magnetic anisotropy is usually larger than the horizontal magnetic anisotropy, and this size affects the thickness of the magnetic domain wall. As the anisotropy increases, the magnetic domain wall thickness tends to decrease. Accordingly, as described above, the structure of the magnetic layer disposed as the first perpendicular magnetic anisotropy region, the first horizontal magnetic anisotropy region, and the second perpendicular magnetic anisotropy region may be more advantageous in terms of device integration.

As another embodiment of the magnetic domain wall logic element,

non-magnetic layer; and

The magnetic layer is

magnetic symmetry breaking region;

including,

Hereinafter, the logic element will be described in detail for each configuration.

A logic device according to another embodiment of the present invention includes a non-magnetic layer and a magnetic layer formed on the non-magnetic layer.

The magnetic layer includes a magnetic symmetry breaking region.

The magnetic layer includes a first horizontal magnetic anisotropy region and a first perpendicular magnetic anisotropy region sequentially extending in a first direction from the magnetic symmetry breaking region.

In addition, the magnetic layer includes a second horizontal magnetic anisotropy region and a second perpendicular magnetic anisotropy region sequentially extending in a second direction from the magnetic symmetry breaking region.

In addition, the magnetic layer includes a third perpendicular magnetic anisotropy region extending in a third direction from the magnetic symmetry breaking region.

The first direction, the second direction, and the third direction may be a straight line or a curved line, and may be a straight line or a curved shape.

The first direction, the second direction, and the third direction may all be in-plane directions of the magnetic layer.

This can be understood with reference to FIG. 10 .

The logic element may be a T-type, a Y-type, etc. as shown in FIG. 10, but is not limited to a specific form.

The first horizontal magnetic anisotropy region, the second horizontal magnetic anisotropy region, and the third perpendicular magnetic anisotropy region may be adjacent to the magnetic symmetry breaking region. Preferably, it may be in contact.

The first perpendicular magnetic anisotropy region and the first horizontal magnetic anisotropy region may be adjacent to each other. Preferably, it may be in contact.

The second perpendicular magnetic anisotropy region and the second horizontal magnetic anisotropy region may be adjacent to each other. Preferably, it may be in contact.

A separate magnetic field may be applied to the magnetic symmetry region to destroy the magnetic symmetry.

Here, the magnetic symmetry means, as described above, when the first perpendicular magnetic anisotropy region, the horizontal magnetic anisotropy region, and the second perpendicular magnetic anisotropy region are sequentially positioned, the first perpendicular magnetic anisotropy region and the second perpendicular magnetic anisotropy region are opposite to each other means having a magnetization direction of

As shown in FIG. 10 , when the first perpendicular magnetic anisotropy region, the first horizontal magnetic anisotropy region, the second perpendicular magnetic anisotropy region, and the second horizontal magnetic anisotropy region exist, if the first perpendicular magnetic anisotropy region and the second perpendicular magnetic anisotropy region exist If the magnetization directions of the regions are opposite, the magnetization directions of the region between the first horizontal magnetic anisotropy region and the second horizontal magnetic anisotropy region cannot be determined by magnetic symmetry (see FIG. 14 ).

Therefore, by applying a separate magnetic field to the region between the first horizontal magnetic anisotropy region and the second horizontal magnetic anisotropy region to destroy this magnetic symmetry, the magnetization directions of the first perpendicular magnetic anisotropy region and the second perpendicular magnetic anisotropy region are opposite In the case of , the magnetization direction may be induced to be aligned in a specific direction.

The logic device may be a NAND device or a NOR device. The type of the logic element may vary depending on the strength or direction of the magnetic field applied to the self-symmetry breakdown region described above.

For example, assuming that the magnetization region in the upward direction is 1, when the magnetization directions of the first perpendicular magnetic anisotropy region and the second perpendicular magnetic anisotropy region are opposite, the magnetization of the magnetic symmetry breaking region is aligned in the upward direction, It can function as a NAND device.

On the other hand, when the magnetization directions of the first perpendicular magnetic anisotropy region and the second perpendicular magnetic anisotropy region are opposite and the magnetization of the magnetic symmetry breaking region is aligned downward, it may function as a NOR element.

Assuming that no separate magnetic field is applied to the magnetic symmetry breaking region, when the first perpendicular magnetic anisotropy region and the second perpendicular magnetic anisotropy region have different magnetization directions, in the magnetic symmetry breaking region, the first perpendicular magnetic anisotropy region When the magnetization of is in the upward direction, the magnetization of the second perpendicular magnetic anisotropy region is in the downward direction (first example), and when the magnetization of the first perpendicular magnetic anisotropy region is in the downward direction and the magnetization of the second perpendicular magnetic anisotropy region is in the upward direction (Example 2) Each has a different direction of magnetization.

Therefore, in order to operate as a NAND device or a NOR device, the magnetization direction of the self-symmetry breaking region in the first and second examples must be fixed in a specific direction, so the strength of the magnetic field actually applied to the self-symmetrical breaking region is The strength of the magnetic field that can make the magnetization directions of the magnetic symmetry breaking regions in the first example and the second example the same as each other must be greater than or equal to the strength of the magnetic field.

Assuming that no separate magnetic field is applied to the magnetic symmetry breaking region, when the first perpendicular magnetic anisotropy region and the second perpendicular magnetic anisotropy region have the same magnetization direction, the magnetic symmetry breaking region is the first perpendicular magnetic anisotropy It has a magnetization direction opposite to the magnetization direction of the region and the second perpendicular magnetic anisotropy region.

Therefore, in order to operate as a NAND or NOR device, when the first perpendicular magnetic anisotropy region and the second perpendicular magnetic anisotropy region have the same magnetization direction, the magnetic symmetry breaking region is first perpendicular to the same as when no magnetic field is applied. Since the magnetization direction must be opposite to the magnetization direction of the magnetic anisotropy region and the second perpendicular magnetic anisotropy region, the strength of the magnetic field actually applied to the magnetic symmetry breaking region is the same as that of the magnetic symmetry breaking region when no magnetic field is applied as described above. It must be less than the strength of the magnetic field that can change the direction of magnetization.

More specifically, the strength of the magnetic field applied to the magnetic symmetry breaking region may be less than or equal to a value satisfying Equation 2 below, and this value may be less than or equal to 1 T depending on the exchange coupling strength and saturation magnetization of the magnetic material. can have a value of

Here, H _C is the upper limit value of the strength of the magnetic field applied to the magnetic symmetry breaking region, M _s is the saturation magnetization value, A is the exchange stiffness, and D is the DMI strength.

In the logic device, the first perpendicular magnetic anisotropy region and the second perpendicular magnetic anisotropy region may be an input terminal, and the third perpendicular magnetic anisotropy region may be an output terminal.

The length of the first horizontal magnetic anisotropy region and the second horizontal magnetic anisotropy region may be a value satisfying Equation 1, and may vary depending on the exchange coupling strength of the magnetic material and the magnitude of the Dzyaloshinskii-Moriya interaction. More specifically, it may be 10 nm to 10 μm.

The logic element may be operated by an in-plane current of the non-magnetic layer.

For example, when a magnetization region opposite to a magnetization direction aligned with the logic element is input, a magnetic domain wall may be formed at the boundary thereof.

The in-plane current may include a first current parallel or anti-parallel to the first direction, a second current parallel or anti-parallel to the second direction, and a third current parallel or anti-parallel to the third direction. .

For example, according to the first in-plane current, the magnetic domain wall moves from the first perpendicular magnetic anisotropy region to the magnetic symmetry breaking region, and according to the second in-plane current, the magnetic domain wall moves from the second perpendicular magnetic anisotropy region to the magnetic symmetry breaking region. The magnetic domain wall may move from the magnetic symmetry breaking region to the third perpendicular magnetic anisotropy region according to the third in-plane current.

The direction of the in-plane current and thus the movement direction of the magnetic domain wall may vary depending on the type and thickness of the magnetic layer and the non-magnetic layer.

In a logic element as another embodiment of the magnetic domain wall logic element, the horizontal magnetic anisotropy region and the vertical magnetic anisotropy region may be reversed.

That is, the magnetic layer may include a magnetic symmetry breaking region; a first perpendicular magnetic anisotropy region and a first horizontal magnetic anisotropy region sequentially extending in a first direction from the magnetic symmetry breaking region; a second perpendicular magnetic anisotropy region and a second horizontal magnetic anisotropy region sequentially extending in a second direction from the magnetic symmetry breaking region; and a third horizontal magnetic anisotropy region extending in a third direction from the magnetic symmetry breaking region.

In this case, the first horizontal magnetic anisotropy region and the second horizontal magnetic anisotropy region may be an input terminal, and the third horizontal magnetic anisotropy region may be an output terminal.

However, when both the input and output terminals are vertical magnetic anisotropy regions and a horizontal magnetic anisotropy region is positioned between them, it may be more preferable in terms of device directivity.

In another aspect of the invention

In the magnetic domain wall logic device manufacturing method,

The forming of the perpendicular magnetic anisotropy region and the horizontal magnetic anisotropy region may be performed through ion irradiation and lithography.

More specifically, the method may include coating a resist on a material to form a magnetic anisotropy region, performing lithography on a specific region to control magnetic anisotropy, and ion-irradiating the entire material.

In the step of performing the lithography, the resist may be removed by performing lithography on a specific area.

In the subsequent ion irradiation step, the resist remains in the area where lithography is not performed, so even if the ion irradiation is performed, there is no resist in the area on which the lithography is performed, so the magnetic anisotropy of the area may change.

In the NOT element manufacturing method,

There is provided a NOT device manufacturing method comprising a.

In the method of manufacturing the logic device,

There is provided a method of manufacturing a logic device comprising a.

The logic device may be a NAND device or a NOR device.

The magnetic symmetry of the first portion may be destroyed by the application of a magnetic field.

The forming of the magnetic symmetry breaking region may be performed by depositing a separate magnetic layer on the first portion to induce a Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction. The magnetic layer may be a hard magnetic layer.

The forming of the magnetic symmetry breaking region may be performed by forming a magnetic structure near the logic element to induce a stray magnetic field. The magnetic structure may be a column structure.

The forming of the magnetic symmetry breaking region may be performed by additionally depositing an antiferromagnetic material to induce an exchange bias.

As described above, it may function as a NAND device or a NOR device depending on the strength or direction of the magnetic field.

Hereinafter, the present invention will be described in more detail through Examples and Experimental Examples. The scope of the present invention is not limited to specific embodiments, and should be construed by the appended claims. In addition, those skilled in the art should understand that many modifications and variations are possible without departing from the scope of the present invention.

<실시예 1> NOT 소자 구동<Example 1> Driving NOT element

The shape of the NOT element is shown in FIG. 1A. That is, the first perpendicular magnetic anisotropy region, the horizontal magnetic anisotropy region, and the second perpendicular magnetic anisotropy region may be sequentially arranged in a straight line.

It has a composite structure in which Pt as the non-magnetic layer, Co as the magnetic layer, and MgO as the oxide layer are stacked, and the size of the entire region may be 500 nm × 50 nm × 1 nm.

The length of the horizontal magnetic anisotropy region may be a value satisfying Equation 1 below.

In this embodiment, A = 1.3 × 10 ^-11 J/m and D = 1.6 × 10 ^-3 J/m ² , and thus the length of the horizontal magnetic anisotropy region was set to about 50 nm.

Based on this, computational simulation was performed, and the Landau-Lifshitz-Gilbert equation used in the computational simulation is as shown in

Equations

3 and 4 below.

where m is the unit magnetization vector, H _eff is the effective magnetic field, α is the damping constant, θ _sh is the spin Hall angle, j is the current density magnitude, t is the magnetic layer thickness, M _s is the saturation magnetization, σ is the injection spin direction, A _ex is the exchange stiffness, D is the DMI strength, K _u is the anisotropy strength, H _demag is the demagnetization field, and H _ext is the external magnetic field.

In this embodiment, M _s = 5.6 × 10 ⁵ A/m, A = 1.3 × 10 ^-11 J/m, D = 1.6 × 10 ^-3 J/m ² , α = 0.3, θ _sh = 0.1, j = 1.0 × 10 ¹² A/m ² _{, K u in} the first perpendicular magnetic anisotropy region = 5.5 × 10 ⁵ J/m ² _{, K u in} the second perpendicular magnetic anisotropy region = 3.0 × 10 ⁵ J/m ² , horizontal magnetic anisotropy The area K _u = 0.

The results according to this are shown in FIG. 8 .

The upward magnetization corresponds to the red region and the downward magnetization corresponds to the blue region. When the input value of the first perpendicular magnetic anisotropy region is changed from the upward magnetization to the downward magnetization, the A magnetic domain wall of directional magnetization and upward magnetization is formed, and the magnetic domain wall gradually moves toward the horizontal magnetic anisotropy region by the in-plane current of the non-magnetic layer.

As a result, all of the first magnetic anisotropy region have downward magnetization (blue region). will do

Accordingly, a magnetic domain wall of downward and upward magnetization is formed in the second magnetic anisotropy region, and the magnetic domain wall gradually moves from the horizontal magnetic anisotropy region toward the second vertical magnetic anisotropy by the in-plane current of the non-magnetic layer, Eventually, all of the second perpendicular magnetic anisotropy regions have upward magnetization (red region).

That is, if the upward magnetization region is 0, the downward magnetization region becomes 1, and it can be confirmed that the present embodiment behaves as a NOT element.

<실시예 2> NAND 소자 구동<Embodiment 2> NAND device driving

As shown in FIG. 10 , a T-shaped NAND device was manufactured, and the size of each region was also set as shown in FIG. 10 .

In addition, it was set to have a composite structure in which Pt as a non-magnetic layer, Co as a magnetic layer, and MgO as an oxide layer were laminated.

When a current is applied as shown in FIG. 1B, the current density is spatially different. In this simulation, an electric field was obtained by numerically solving the Laplace equation by applying a voltage of 80 mV to the lower left and upper left edges and connecting the right edge to the ground. Specifically, 0 - 0.7 ns : 80 mV, 0.7 - 3 ns : 0, 3 ns - 3.7 ns : 80 mV, 3.7 ns - 6 ns : 0, 6 ns-6.7 ns : 80 mV, 6.7ns-9ns : 0 and The same voltage was applied.

Since there is a relationship of J = σE, a current density distribution as shown in FIG. 11 is obtained when the electrical conductivity of Pt, which is mainly used as a spin flow injection layer, is used.

Computational simulation is performed in the same manner as in Example 1, but in this example, M _s = 5.6 × 10 ⁵ A/m, A = 1.3 × 10 ^-11 J/m, D = 1.6 × 10 ^-3 J/m ² , α = 0.3, θ _sh _{= 0.1, K u} of the first perpendicular magnetic anisotropy region and the second perpendicular magnetic anisotropy region = 5.5 × 10 ⁵ J/m ² _{, K u} of the third perpendicular magnetic anisotropy region = 2.4 × 10 ⁵ J/m ² _{, K u} = 0 in the horizontal magnetic anisotropy region.

^{In addition, a current density of j = 1.6 × 10 12} A/m ² was applied from the first perpendicular magnetic anisotropy region and the second perpendicular magnetic anisotropy region to the magnetic symmetry breaking region, respectively, and the third perpendicular magnetic anisotropy region in the magnetic symmetry breaking region A current density of j = 4.0 × 10 ¹² A/m ² was applied.

In addition, a magnetic field of −40 mT was applied to the magnetic symmetry breaking region.

In the micromagnetic computational simulation of FIG. 11 , it was confirmed that the current density increased locally at (50 nm, 80 nm) and near (50 nm, 120 nm).

The result is shown in FIG. 12, and comparing it with Table 1 below, which is the truth table of the NAND device, it can be confirmed that the NAND device is well driven.

ININ		OUT OUT
00	00	1One
1One	00	1One
00	1One	1One
1One	1 One	00

<실시예 3> NOR 소자 구동<Embodiment 3> NOR element driving

It was prepared in the same manner as in Example 2, except that a magnetic field of 40 mT was applied to the magnetic symmetry breaking region.

The results for this are shown in FIG. 13, and comparing this with Table 2, which is the truth table of the NOR device, it can be confirmed that the NOR device is well driven.

ININ		OUT OUT
00	00	1One
1One	00	00
00	1One	00
1One	1 One	00

10 perpendicular magnetic anisotropy region

11 first perpendicular magnetic anisotropy region

12 Second perpendicular magnetic anisotropy region

13 Third perpendicular magnetic anisotropy region

20 Horizontal magnetic anisotropy region

21 first horizontal magnetic anisotropy region

22 second horizontal magnetic anisotropy region

30 Magnetic Symmetry Breakdown Zone

100 magnetic layer

200 non-magnetic layer

1000 NOT element

2000 NAND device or NOR device

Claims

non-magnetic layer; and

A magnetic domain wall logic device comprising a magnetic layer formed on the non-magnetic layer,

The magnetic layer is

perpendicular magnetic anisotropy region; and

a horizontal magnetic anisotropy region adjacent to the perpendicular magnetic anisotropy region;

includes,

The magnetic domain wall logic device, characterized in that the magnetic domain wall logic device is operated by the in-plane current of the non-magnetic layer.
According to claim 1,

The magnetic domain wall logic element is any one selected from the group consisting of a NOT element, a NOR element, and a NAND element.
According to claim 1,

The magnetic domain wall logic device, characterized in that the perpendicular magnetic anisotropy region and the horizontal magnetic anisotropy region are disposed adjacent to each other in an in-plane direction of the magnetic layer.
According to claim 1,

The magnetic layer is a magnetic domain wall logic device, characterized in that it includes at least one selected from the group consisting of a ferromagnetic material and a ferrimagnetic material.
5. The method of claim 4,

The magnetic layer is

cobalt (Co), iron (Fe), nickel (Ni) and alloys thereof; and

TbCo, TbFe, GdCo, GdFe, GdFeCo, Fe 3 O 4 , Yttrium iron garnet (YIG), TmIG, and TbIG;

A magnetic domain wall logic device comprising at least one selected from the group consisting of
According to claim 1,

The magnetic domain wall logic device, characterized in that the non-magnetic layer includes at least one selected from the group consisting of a non-magnetic metal and a topological insulator.
7. The method of claim 6,

The nonmagnetic layer is made of platinum (Pt), palladium (Pd), tantalum (Ta), titanium (Ti), tungsten (W), gold (Au), Bi 2 Se 3 , Bi 2 Te 3 and Ag 2 Te 3 A magnetic domain wall logic device comprising at least one selected from the group consisting of.
According to claim 1,

The magnetic domain wall logic device, characterized in that the thickness of the magnetic layer is 0.1 nm to 10 nm.
According to claim 1,

The magnetic domain wall logic device further comprises an oxide layer formed on the magnetic layer.
10. The method of claim 9,

The oxide layer comprises at least one selected from the group consisting of MgO, AlO x , SiO x and SiN x .
non-magnetic layer; and

A magnetic domain wall logic device comprising a magnetic layer formed on the non-magnetic layer,

The magnetic layer is

a first perpendicular magnetic anisotropy region and a second perpendicular magnetic anisotropy region; and

a horizontal magnetic anisotropy region positioned between the first perpendicular magnetic anisotropy region and the second perpendicular magnetic anisotropy region;

including,

The NOT element is a NOT element, characterized in that operated by the in-plane current of the non-magnetic layer.
12. The method of claim 11,

The NOT device, characterized in that the first perpendicular magnetic anisotropy region and the second perpendicular magnetic anisotropy region have magnetization directions opposite to each other.
12. The method of claim 11,

The NOT element, characterized in that the first perpendicular magnetic anisotropy region, the horizontal magnetic anisotropy region, and the second perpendicular magnetic anisotropy region are sequentially arranged adjacent to each other in the in-plane direction.
12. The method of claim 11,

The length of the horizontal magnetic anisotropy region is a NOT device, characterized in that 10 nm to 10 ㎛.
non-magnetic layer; and

A magnetic domain wall logic device comprising a magnetic layer formed on the non-magnetic layer,

The magnetic layer is

magnetic symmetry breaking region;

a first horizontal magnetic anisotropy region and a first perpendicular magnetic anisotropy region sequentially extending in a first direction from the magnetic symmetry breaking region;

a second horizontal magnetic anisotropy region and a second perpendicular magnetic anisotropy region sequentially extending in a second direction from the magnetic symmetry breaking region; and

a third perpendicular magnetic anisotropy region extending in a third direction from the magnetic symmetry breaking region;

including,

The logic device is characterized in that it is operated by the in-plane current of the non-magnetic layer.
16. The method of claim 15,

The logic device is a NAND device or a NOR device.
16. The method of claim 15,

The magnetic symmetry breaking region is a logic device, characterized in that the magnetic symmetry is destroyed by applying a separate magnetic field.
16. The method of claim 15,

A logic device, characterized in that the strength of the applied magnetic field is 1 T or less.
16. The method of claim 15,

The length of the first horizontal magnetic anisotropy region and the second horizontal magnetic anisotropy region is 10 nm to 10 μm.
16. The method of claim 15,

The logic device according to claim 1, wherein the first perpendicular magnetic anisotropy region and the second perpendicular magnetic anisotropy region are input terminals, and the third perpendicular magnetic anisotropy region is an output terminal.
16. The method of claim 15,

The first direction, the second direction, and the third direction are all in-plane directions of the magnetic layer.
16. The method of claim 15,

The in-plane current is

a first current parallel or antiparallel to the first direction;

a second current parallel or antiparallel to the second direction; and

a third current parallel or antiparallel to the third direction;

A logic device comprising a.
The method for manufacturing the magnetic domain wall logic device of claim 1,

forming a perpendicular magnetic anisotropy region and a horizontal magnetic anisotropy region in a magnetic layer having a complex structure including a non-magnetic layer and a magnetic layer formed on the non-magnetic layer;

A method of manufacturing a magnetic domain wall logic device comprising a.
24. The method of claim 23,

The forming of the perpendicular magnetic anisotropy region and the horizontal magnetic anisotropy region is performed through ion irradiation or lithography.
The method for manufacturing the NOT element of claim 11,

forming a perpendicular magnetic anisotropy region and a horizontal magnetic anisotropy region in a magnetic layer having a complex structure including a non-magnetic layer and a magnetic layer formed on the non-magnetic layer;

A NOT device manufacturing method comprising a.
The method for manufacturing the logic device of claim 15,

A third perpendicular magnetic anisotropy region in a magnetic layer having a composite structure including a non-magnetic layer and a magnetic layer formed on the non-magnetic layer, and a first horizontal magnetic anisotropy sequentially extending in a first direction from a first portion of the third perpendicular magnetic anisotropy region forming a region and a first perpendicular magnetic anisotropy region, a second horizontal magnetic anisotropy region and a second perpendicular magnetic anisotropy region sequentially extending in a second direction from a first portion of the third perpendicular magnetic anisotropy region; and

forming a magnetic symmetry breaking region by breaking magnetic symmetry by applying a magnetic field to a first portion of the third perpendicular magnetic anisotropy region;

A method of manufacturing a logic device comprising a.
27. The method of claim 26,

The step of forming the self-symmetry breakdown region is

a method of inducing a Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction by depositing a separate magnetic layer on the first portion;

a method of inducing a stray magnetic field by forming a magnetic structure near the logic element; and

additional deposition of an antiferromagnetic material to induce an exchange bias;

A method of manufacturing a logic device, characterized in that it is performed by at least one method selected from the group consisting of
27. The method of claim 26,

The method of manufacturing a logic device, characterized in that the strength of the magnetic field applied in the step of forming the magnetic symmetry breaking region is 1 T or less.
non-magnetic layer; and

A magnetic domain wall logic device comprising a magnetic layer formed on the non-magnetic layer,

The magnetic layer is

a first horizontal magnetic anisotropy region and a second horizontal magnetic anisotropy region; and

a perpendicular magnetic anisotropy region positioned between the first horizontal magnetic anisotropy region and the second horizontal magnetic anisotropy region;

including,

The NOT element is a NOT element, characterized in that operated by the in-plane current of the non-magnetic layer.
non-magnetic layer; and

A magnetic domain wall logic device comprising a magnetic layer formed on the non-magnetic layer,

The magnetic layer is

magnetic symmetry breaking region;

a first perpendicular magnetic anisotropy region and a first horizontal magnetic anisotropy region sequentially extending in a first direction from the magnetic symmetry breaking region;

a second perpendicular magnetic anisotropy region and a second horizontal magnetic anisotropy region sequentially extending in a second direction from the magnetic symmetry breaking region; and

a third horizontal magnetic anisotropy region extending in a third direction from the magnetic symmetry breaking region;

including,

The logic device is characterized in that it is operated by the in-plane current of the non-magnetic layer.