CN111293214A - Magnetic tunneling junction device based on flexible substrate and its fabrication method - Google Patents

Abstract

The invention provides a magnetic tunnel junction device based on a flexible substrate and a manufacturing method thereof. The device includes: a first metal connection layer formed on a flexible CMOS circuit substrate, a first metal transition layer, a fixed magnetic layer, a tunnel A through layer, a free magnetic layer, a second metal transition layer and a second metal connection layer. The invention adopts the atomic layer deposition process, the chemical vapor deposition process or the film stripping-transfer process to make the free magnetic layer, which can prevent the tunneling layer from being damaged by sputtering particles and improve the quality of the tunneling layer. The fixed magnetic layer and the free magnetic layer of the present invention are two-dimensional ferromagnetic material layers, and their thickness is relatively thin, on the one hand, the magnetization orientation speed of the magnetic tunnel junction device can be improved, and on the other hand, a relatively light and thin magnetic tunnel junction device can be obtained. . In the invention, the magnetic tunnel junction device can be directly prepared on the flexible substrate circuit, the device preparation cost is reduced, and the application range thereof is expanded.

Description

Magnetic tunneling junction device based on flexible substrate and its fabrication method

technical field

The invention belongs to the field of semiconductor integrated circuit design and manufacture, in particular to a magnetic tunnel junction device based on a flexible substrate and a manufacturing method thereof.

Background technique

As the use of portable computing devices and wireless communication devices increases, memory devices may require higher density, lower power consumption, and/or non-volatility. The magnetic memory device may be able to meet the above-mentioned technical requirements.

Many electronic devices contain electronic memory. Electronic storage can be volatile or non-volatile. Non-volatile memory can store data when power is lost, whereas volatile memory cannot store data when power is lost. Magnetoresistive random access memory (MRAM) is a promising candidate for the next generation of electronic memory due to its advantages over current electronic memory. MRAM is generally faster and has better endurance than current non-volatile memories such as flash random access memory. Compared to current volatile memories such as dynamic random access memory (DRAM) and static random access memory (SRAM), MRAM typically has similar performance and density, but MRAM has lower power consumption. Since MTJ devices have high operating speed and low power consumption and are used to replace capacitors of DRAMs, MTJ devices can be applied to image devices and mobile devices having low power consumption and high speed.

The magnetoresistive device has low resistance when the spin directions (ie, the directions of the magnetic fluxes) of the two magnetic layers are the same as each other, and has high resistance when the spin directions are opposite to each other. In this way, bit data can be written into a magnetoresistive memory device using a change in cell resistance that is dependent on the magnetization state of the magnetic layer. A magnetoresistive memory having an MTJ structure will be described by way of example. In an MTJ memory cell having a structure composed of a ferromagnetic layer/insulating layer/ferromagnetic layer, when electrons passing through the first ferromagnetic layer pass through the insulating layer serving as a tunneling barrier, tunneling The penetration probability varies depending on the magnetization direction of the second ferromagnetic layer. That is, when the magnetization directions of the two ferromagnetic layers are parallel, the tunneling current is maximized, and when they are antiparallel, the tunneling current is minimized. For example, it can be considered that when the resistance is high, data "1" is written, and when the resistance is low, data "0" is written. When current flows through the magnetic layer, the current will be polarized, forming a spin-polarized current. The spin electron transfers the spin momentum to the magnetic moment of the free magnetic layer, so that the magnetic moment of the spin magnetic layer changes direction after acquiring the spin momentum. This process is called spin transfer torque. The current realizes the writing of information.

The core of the STT-MRAM memory cell is still an MTJ, which consists of two ferromagnetic layers of different thicknesses and a non-magnetic isolation layer several nanometers thick. With external circuitry, current can flow through the MTJ in a direction perpendicular to the MJT surface. When an electric current passes through a thicker ferromagnetic layer (called a pinned magnetic layer), the electrons are spin-polarized in the direction of the magnetic moment of the pinned magnetic layer. If the thickness of the intermediate nonmagnetic spacer is small enough to ensure a high degree of polarization, the spin-polarized electrons are able to transfer their spin angular momentum to the thinner ferromagnetic layer (called the free magnetic layer), changing the free magnetic The magnetization equilibrium state of the layer. The fixed magnetic layer that plays the role of "polarization layer" is generally thick (tens of nanometers), its saturation magnetization is very large, and its equilibrium state will not change. On the contrary, the free magnetic layer to be affected by the spin moment effect is generally very thin, and its saturation magnetization is small, so its magnetic moment vector can freely change its orientation according to the polarization direction of the spin electrons in the spin current.

The structure of the STT-MRAM memory cell is simple, it omits the additional write information line with a magnetic shell, minimizes the preparation process, and reduces the cross-sectional area of the memory cell, high storage density, and fast storage speed. Design requirements for high performance computer systems.

In the MTJ spin valve of the STT-MRAM memory cell, the tunneling probability of spin electrons is related to the material of each magnetic layer, the material of the tunneling layer, and the thickness. According to the tunneling probability formula, the thinner the tunneling layer, the greater the tunneling probability, and the higher the quality requirements of the tunneling layer.

SUMMARY OF THE INVENTION

In view of the above-mentioned shortcomings of the prior art, the purpose of the present invention is to provide a magnetic tunneling junction device based on a flexible substrate and a manufacturing method thereof, which are used to solve the problems in the prior art that the growth quality of the tunneling layer is difficult to guarantee, and the magnetic The overall thickness of the tunnel junction device is relatively large.

In order to achieve the above object and other related objects, the present invention provides a method for manufacturing a magnetic tunnel junction device based on a flexible substrate. The manufacturing method includes the steps of: 1) providing a CMOS circuit substrate, the CMOS circuit substrate including a flexible a substrate, a CMOS circuit layer on the flexible substrate, and a flexible dielectric layer covering the CMOS circuit layer, a first metal connection layer is formed on the CMOS circuit substrate and the first metal connection layer is In the planarization process, the first metal connection layer is connected to the drain of the MOS transistor of the CMOS circuit; 2) a first metal transition layer is formed on the first metal connection layer; 3) a first metal transition layer is formed on the first metal A fixed magnetic layer is formed on the transition layer, and the fixed magnetic layer is a two-dimensional magnetic material layer; 4) A tunneling layer is formed on the fixed magnetic layer, and the tunneling layer is a two-dimensional insulating material layer; 5) Atomic layer deposition process, chemical vapor deposition process or thin film lift-off-transfer process to deposit a free magnetic layer on the tunneling layer, the free magnetic layer is a two-dimensional magnetic material; 6) forming a second metal on the free magnetic layer transition layer; 7) forming a second metal connection layer on the second metal transition layer; 8) patterning and etching the second metal connection layer, the second metal transition layer, the tunnel isolation bottom layer, the free magnetic layer, A tunnel layer, a fixed magnetic layer, a tunnel isolation top layer, a first metal transition layer and a first metal connection layer are used to form a magnetic tunnel junction device with a column structure.

Optionally, the first metal transition layer has a flat surface, the fixed magnetic layer is closely combined with the first metal transition layer, and the Fermi level of the first metal transition layer is the same as that of the fixed magnetic layer. The Fermi levels are equal or similar to reduce the contact resistance between the fixed magnetic layer and the first metal transition layer.

Optionally, the material of the fixed magnetic layer includes one of CrGeTe ₃ and CrI ₃ , and the material of the free magnetic layer includes one of CrGeTe ₃ and CrI ₃ .

Optionally, the number of the fixed magnetic layer including two-dimensional ferromagnetic material layers is not less than 10 layers.

Optionally, the number of the free magnetic layer including two-dimensional ferromagnetic material layers is not more than 5 layers.

Optionally, the two-dimensional insulating material layer includes one of two-dimensional boron nitride, fluorinated graphene and graphene oxide.

Optionally, the shape of the magnetic tunnel junction device includes a cylindrical structure, and the diameter of the cylindrical structure ranges from 10 nm to 200 nm.

Optionally, the flexible substrate comprises polydimethylsiloxane, polyimide, polyethylene, polypropylene, polyethylene terephthalate and polyethylene terephthalate. A sort of.

Optionally, the surface roughness of the flexible medium layer is less than 0.2 nm.

The present invention also provides a magnetic tunnel junction device based on a flexible substrate, comprising: a first metal connection layer, the first metal connection layer is formed on a CMOS circuit substrate, and the CMOS circuit substrate includes a flexible substrate, a CMOS circuit layer on the flexible substrate and a flexible dielectric layer covering the CMOS circuit layer, the first metal connection layer is connected to the drain of the MOS transistor of the CMOS circuit; the first metal transition layer, is formed on the first metal connection layer; the fixed magnetic layer is formed on the first metal transition layer, and the fixed magnetic layer is a two-dimensional magnetic material layer; the tunneling layer is formed on the fixed magnetic layer, The tunneling layer is a two-dimensional insulating material layer; the free magnetic layer is formed on the tunneling layer, and the free magnetic layer is a two-dimensional magnetic material; the second metal transition layer is formed on the free magnetic layer ; A second metal connection layer is formed on the second metal transition layer.

Optionally, the first metal transition layer has a flat surface, the fixed magnetic layer is closely combined with the first metal transition layer, and the Fermi level of the first metal transition layer is the same as that of the fixed magnetic layer. The Fermi levels are equal or similar to reduce the contact resistance between the fixed magnetic layer and the first metal transition layer.

Optionally, the shape of the magnetic tunnel junction device includes a cylindrical structure, and the diameter of the cylindrical structure ranges from 10 nm to 200 nm.

Optionally, the material of the fixed magnetic layer includes one of CrGeTe ₃ and CrI ₃ , and the material of the free magnetic layer includes one of CrGeTe ₃ and CrI ₃ .

Optionally, the number of the fixed magnetic layer including two-dimensional ferromagnetic material layers is not less than 10 layers.

Optionally, the number of the free magnetic layer including two-dimensional ferromagnetic material layers is not more than 5 layers.

Optionally, the two-dimensional insulating material layer includes one of two-dimensional boron nitride, fluorinated graphene and graphene oxide.

Optionally, the flexible substrate comprises polydimethylsiloxane, polyimide, polyethylene, polypropylene, polyethylene terephthalate and polyethylene terephthalate. A sort of.

Optionally, the surface roughness of the flexible medium layer is less than 0.2 nm.

As described above, the flexible substrate-based magnetic tunnel junction device and the fabrication method thereof of the present invention have the following beneficial effects:

In the present invention, after the tunneling layer is fabricated, the atomic layer deposition process, the chemical vapor deposition process or the thin film stripping-transfer process is used to make the free magnetic layer. Compared with the sputtering process, the tunneling layer can be prevented from being sputtered by particles. damage and improve the quality of the tunneling layer.

By adopting atomic layer deposition process, chemical vapor deposition process or thin film stripping-transfer process to make the free magnetic layer, the tunneling layer of the present invention can be selected as a two-dimensional insulating material layer with a very thin thickness, the consistency of the tunneling layer is very good, and it can be While ensuring the quality and function of the tunneling layer, the tunneling probability is greatly improved.

The fixed magnetic layer and the free magnetic layer of the present invention are two-dimensional ferromagnetic material layers, and their thickness is relatively thin, on the one hand, the magnetization orientation speed of the magnetic tunnel junction device can be improved, and on the other hand, a relatively light and thin magnetic tunnel junction device can be obtained. .

In the invention, the magnetic tunnel junction device can be directly prepared on the flexible substrate circuit, the device preparation cost is reduced, and the application range thereof is expanded.

Description of drawings

FIG. 1 to FIG. 8 are schematic structural diagrams of each step of the fabrication method of the magnetic tunnel junction device of the present invention.

FIG. 9 is a schematic diagram showing the structure of the tunneling layer of the magnetic tunnel junction device of the present invention.

FIG. 10 is a schematic structural diagram of the two-dimensional free magnetic layer of the magnetic tunnel junction device of the present invention.

FIG. 11 is a schematic flow chart showing the steps of the fabrication method of the magnetic tunnel junction device of the present invention.

Component label description

10 CMOS circuit substrate

101 Flexible substrate

102 CMOS circuit layers

103 Flexible dielectric layer

201 The first metal connection layer

202 The first metal transition layer

203 Fixed magnetic layer

204 Tunneling layer

205 Free magnetic layer

206 The second metal transition layer

207 Second metal connection layer

Steps S11～S18

Detailed ways

The embodiments of the present invention are described below through specific specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

Please refer to Figure 1 to Figure 11. It should be noted that the diagrams provided in this embodiment are only to illustrate the basic concept of the present invention in a schematic way, so the diagrams only show the components related to the present invention rather than the number, shape and the number of components in the actual implementation. For dimension drawing, the type, quantity and proportion of each component can be changed at will in actual implementation, and the component layout may also be more complicated.

As shown in FIG. 1 and FIG. 11 , step 1) S11 is first performed, a CMOS circuit substrate 10 is provided, a first metal connection layer 201 is formed on the CMOS circuit substrate 10 and the first metal connection layer 201 is flattened The first metal connection layer 201 is connected to the drain of the MOS transistor of the CMOS circuit.

In this embodiment, the CMOS circuit substrate 10 includes a flexible substrate 101, a CMOS circuit layer 102 on the flexible substrate 101, and a flexible dielectric layer 103 covering the CMOS circuit layer 102, wherein the The surface roughness of the flexible dielectric layer 103 is less than 0.2 nm. For example, the flexible substrate 101 includes one of polydimethylsiloxane, polyimide, polyethylene, polypropylene, polyethylene terephthalate, and polyethylene terephthalate kind. The present invention adopts the flexible substrate 101, and the formed magnetic tunneling junction device is lighter and thinner than the magnetic tunneling junction device of the existing solid ferromagnetic material, the formed MRAM is suitable for the application of flexible circuit, and the flexible substrate 101 There is basically no requirement for the macro topography of the flexible substrate 101. For example, the flexible substrate 101 can be a circle, an ellipse, a polygon or any other desired shape. The processing technology of the flexible substrate 101 is relatively simple, compared with the existing The magnetic tunnel junction devices of solid ferromagnetic materials have greater advantages.

The material of the first metal connection layer 201 may be one of W, Cu and Al.

The first metal connection layer 201 in this embodiment is formed on a flat flexible dielectric layer 103 , and the first metal connection layer 201 can be planarized to obtain a first metal connection layer 201 with a flat surface, so as to improve the follow-up Flatness of the first metal transition layer 202 .

As shown in FIG. 2 and FIG. 11 , step 2) S12 is performed to form a first metal transition layer 202 on the first metal connection layer 201 .

For example, the first metal transition layer 202 has a flat surface, and the Fermi energy level of the first metal transition layer 202 is equal to or similar to the Fermi energy level of the subsequently formed fixed magnetic layer 203, so as to reduce the fixed magnetic energy Contact resistance between the layer 203 and the first metal transition layer 202 .

As shown in FIG. 3 and FIG. 11 , then step 3) S13 is performed, and the fixed magnetic layer 203 is deposited on the first metal transition layer 202 by using an atomic layer deposition process, a chemical vapor deposition process or a thin film lift-off-transfer process, The fixed magnetic layer is a two-dimensional magnetic material layer.

Since the first metal transition layer 202 has a flat surface, and the Fermi level of the first metal transition layer 202 is equal to or similar to the Fermi level of the pinned magnetic layer 203 , the pinned magnetic layer can be 203 is closely combined with the first metal transition layer 202 to reduce the contact resistance between the fixed magnetic layer 203 and the first metal transition layer 202 .

For example, the material of the fixed magnetic layer includes one of CrGeTe ₃ and CrI ₃ . The fixed magnetic layer of the present invention adopts a two-dimensional magnetic material, and a relatively light and thin magnetic tunnel junction device can be obtained.

Atomic layer deposition process, chemical vapor deposition process or thin film lift-off-transfer process can effectively improve the deposition quality of the fixed magnetic layer 203 , and the surface of the fixed magnetic layer 203 can be more flat, which can effectively improve the quality of the tunneling layer 204 produced subsequently.

The number of the fixed magnetic layer including two-dimensional ferromagnetic material layers is not less than 10 layers. The type of the two-dimensional ferromagnetic material layer may be single, or may be a composite stack structure of multiple magnetic layers, and the magnetization direction of the fixed magnetic layer does not change under the action of read and write currents.

As shown in FIG. 4 and FIG. 11 , then step 4) S14 is performed to form a tunneling layer 204 on the fixed magnetic layer 203 .

As an example, the tunneling layer 204 is a two-dimensional insulating material layer with a single crystal structure, as shown in FIG. 9 . For example, the two-dimensional insulating material layer includes one of two-dimensional boron nitride, fluorinated graphene, and graphene oxide. In this embodiment, the atomic layer deposition process is used to form the free magnetic layer 205, so that the tunneling layer 204 in this embodiment can be a two-dimensional insulating material layer with a very thin thickness. The consistency of the tunneling layer 204 is very good, which can ensure In addition to the quality and function of the tunneling layer 204 , the tunneling probability is greatly improved, and at the same time, the magnetization directions of the fixed magnetic layer and the free magnetic layer can be prevented from having a strong influence on each other. The tunneling layer 204 can be formed by an atomic layer deposition process, etc., to avoid damage to the interface between the fixed magnetic layer 203 and the tunneling layer 204 caused by sputtering particles.

As shown in FIG. 5 and FIG. 11 , then step 5) S15 is performed, and a free magnetic layer 205 is deposited on the tunneling layer 204 by an atomic layer deposition process, a chemical vapor deposition process or a thin film lift-off-transfer process. The layer 205 is a two-dimensional ferromagnetic material layer, and the schematic structure of the free magnetic layer is shown in FIG. 10 .

In this embodiment, after the tunneling layer 204 is fabricated, the free magnetic layer 205 is fabricated by an atomic layer deposition process, a chemical vapor deposition process or a thin film lift-off-transfer process. Compared with the sputtering process, the tunneling layer 204 can be prevented from Damaged by sputtered particles, the quality of the tunneling layer 204 is improved.

The material of the free magnetic layer 205 may be one of CrGeTe ₃ and CrI ₃ . The free magnetic layer includes two-dimensional ferromagnetic material layers in a quantity of no more than 5 layers, and the type of the two-dimensional ferromagnetic material layer may be single or a composite stack structure of multiple The magnetization direction of the magnetic layer does not change under the action of the read current, while the magnetization direction of the magnetic layer changes under the action of the read current. The free magnetic layer of the present invention is a two-dimensional ferromagnetic material layer, and its thickness is relatively thin, on the one hand, the magnetization orientation speed of the magnetic tunnel junction device can be improved, and on the other hand, a relatively light and thin magnetic tunnel junction device can be obtained.

As shown in FIG. 6 and FIG. 11 , step 6) S16 is performed to form a second metal transition layer 206 on the free magnetic layer 205 .

As shown in FIG. 7 and FIG. 11 , then step 7) S17 is performed to form a second metal connection layer 207 on the second metal transition layer 206 .

For example, the material of the second metal connection layer 207 may be one of W, Cu and Al.

As shown in FIG. 8 and FIG. 11 , step 8) is finally performed by patterning and etching the second metal connection layer 207 , the second metal transition layer 206 , the free magnetic layer 205 , the tunneling layer 204 , the fixed magnetic layer 203 , the first A metal transition layer 202 and a first metal connection layer 201 are used to form a magnetic tunnel junction device with a columnar structure.

For example, the shape of the magnetic tunnel junction device includes a cylindrical structure, and the diameter of the cylindrical structure ranges from 10 nm to 200 nm.

As shown in FIG. 8 , this embodiment further provides a magnetic tunnel junction device, including: a first metal connection layer 201 , the first metal connection layer 201 is formed on a CMOS circuit substrate 10 , the first metal connection layer 201 is The connection layer 201 is connected to the drain of the MOS transistor of the CMOS circuit; the first metal transition layer 202 is formed on the first metal connection layer 201 ; the fixed magnetic layer 203 is formed on the first metal transition layer 202 above, the fixed magnetic layer 203 is a two-dimensional magnetic material layer; the tunneling layer 204 is formed on the fixed magnetic layer 203; the free magnetic layer 205 is formed on the tunneling layer 204, and the free magnetic layer 205 is a two-dimensional ferromagnetic material layer, the tunneling layer 204 includes two-dimensional insulating material layers with a number of 1 to 5 layers; a second metal transition layer 206 is formed on the free magnetic layer 205, and the free magnetic The layer 205 is a two-dimensional magnetic material; the second metal connection layer 207 is formed on the second metal transition layer 206 .

In this embodiment, the CMOS circuit substrate 10 includes a flexible substrate 101, a CMOS circuit layer 102 on the flexible substrate 101, and a flexible dielectric layer 103 covering the CMOS circuit layer 102, wherein the The surface roughness of the flexible dielectric layer 103 is less than 0.2 nm. For example, the flexible substrate 101 includes one of polydimethylsiloxane, polyimide, polyethylene, polypropylene, polyethylene terephthalate, and polyethylene terephthalate kind. The present invention adopts the flexible substrate 101, and the formed magnetic tunneling junction device is lighter and thinner than the magnetic tunneling junction device of the existing solid ferromagnetic material, the formed MRAM is suitable for the application of flexible circuit, and the flexible substrate 101 There is basically no requirement for the macro topography of the flexible substrate 101. For example, the flexible substrate 101 can be a circle, an ellipse, a polygon or any other desired shape. The processing technology of the flexible substrate 101 is relatively simple, compared with the existing The magnetic tunnel junction devices of solid ferromagnetic materials have greater advantages.

For example, the first metal transition layer 202 has a flat surface, the fixed magnetic layer 203 is closely combined with the first metal transition layer 202 , and the Fermi level of the first metal transition layer 202 is the same as the fixed magnetic layer 202 . The Fermi levels of the layers 203 are equal or similar, so as to reduce the contact resistance between the fixed magnetic layer 203 and the first metal transition layer 202 .

In this embodiment, the CMOS circuit substrate 10 includes a flexible substrate 101, a CMOS circuit layer 102 on the flexible substrate 101, and a flexible dielectric layer 103 covering the CMOS circuit layer 102, wherein the The surface roughness of the flexible dielectric layer 103 is less than 0.2 nm. For example, the flexible substrate 101 includes one of polydimethylsiloxane, polyimide, polyethylene, polypropylene, polyethylene terephthalate, and polyethylene terephthalate kind. The present invention adopts the flexible substrate 101, and the formed magnetic tunneling junction device is lighter and thinner than the magnetic tunneling junction device of the existing solid ferromagnetic material, the formed MRAM is suitable for the application of flexible circuit, and the flexible substrate 101 There is basically no requirement for the macro topography of the flexible substrate 101. For example, the flexible substrate 101 can be a circle, an ellipse, a polygon or any other desired shape. The processing technology of the flexible substrate 101 is relatively simple, compared with the existing The magnetic tunnel junction devices of solid ferromagnetic materials have greater advantages.

The material of the first metal connection layer 201 may be one of W, Cu and Al.

The first metal connection layer 201 in this embodiment is formed on a flat flexible dielectric layer 103 , and the first metal connection layer 201 can be planarized to obtain a first metal connection layer 201 with a flat surface, so as to improve the follow-up Flatness of the first metal transition layer 202 . For example, the shape of the magnetic tunnel junction device includes a cylindrical structure, and the diameter of the cylindrical structure ranges from 10 nm to 200 nm.

The tunneling layer 204 is a two-dimensional insulating material layer with a single crystal structure, as shown in FIG. 9 . For example, the two-dimensional insulating material layer includes one of two-dimensional boron nitride, fluorinated graphene, and graphene oxide. The tunneling layer of the present invention is a two-dimensional insulating material, and the consistency of the tunneling layer is very good, which can greatly improve the tunneling probability while ensuring the quality and function of the tunneling layer, and at the same time, can make the fixed magnetic layer and the free magnetic layer. The magnetization directions of the layers do not strongly influence each other.

For example, the material of the fixed magnetic layer 203 includes one of CrGeTe ₃ and CrI ₃ , and the material of the free magnetic layer 205 includes one of CrGeTe ₃ and CrI ₃ . The number of the fixed magnetic layer including two-dimensional ferromagnetic material layers is not less than 10 layers. The type of the two-dimensional ferromagnetic material layer may be single, or may be a composite stack structure of multiple magnetic layers, and the magnetization direction of the fixed magnetic layer does not change under the action of read and write currents. The free magnetic layer includes two-dimensional ferromagnetic material layers in a quantity of no more than 5 layers, and the type of the two-dimensional ferromagnetic material layer may be single or a composite stack structure of multiple The magnetization direction of the magnetic layer does not change under the action of the read current, while the magnetization direction of the magnetic layer changes under the action of the read current. The fixed magnetic layer and the free magnetic layer of the present invention are two-dimensional ferromagnetic material layers, and their thickness is relatively thin, on the one hand, the magnetization orientation speed of the magnetic tunnel junction device can be improved, and on the other hand, a relatively light and thin magnetic tunnel junction device can be obtained. .

As described above, the flexible substrate-based magnetic tunnel junction device and the fabrication method thereof of the present invention have the following beneficial effects:

In the present invention, after the tunneling layer is fabricated, the atomic layer deposition process, the chemical vapor deposition process or the thin film stripping-transfer process is used to make the free magnetic layer. Compared with the sputtering process, the tunneling layer can be prevented from being sputtered by particles. damage and improve the quality of the tunneling layer.

By adopting atomic layer deposition process, chemical vapor deposition process or thin film stripping-transfer process to make the free magnetic layer, the tunneling layer of the present invention can be selected as a two-dimensional insulating material layer with a very thin thickness, the consistency of the tunneling layer is very good, and it can be While ensuring the quality and function of the tunneling layer, the tunneling probability is greatly improved.

The fixed magnetic layer and the free magnetic layer of the present invention are two-dimensional ferromagnetic material layers, and their thickness is relatively thin, on the one hand, the magnetization orientation speed of the magnetic tunnel junction device can be improved, and on the other hand, a relatively light and thin magnetic tunnel junction device can be obtained. .

In the invention, the magnetic tunnel junction device can be directly prepared on the flexible substrate circuit, the device preparation cost is reduced, and the application range thereof is expanded. Therefore, the present invention effectively overcomes various shortcomings in the prior art and has high industrial utilization value.

The above-mentioned embodiments merely illustrate the principles and effects of the present invention, but are not intended to limit the present invention. Anyone skilled in the art can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field without departing from the spirit and technical idea disclosed in the present invention should still be covered by the claims of the present invention.

Claims (18)

1. a fabrication method of a magnetic tunnel junction device based on a flexible substrate, characterized in that the fabrication method comprises the steps: 1) Provide a CMOS circuit substrate, the CMOS circuit substrate includes a flexible substrate, a CMOS circuit layer on the flexible substrate, and a flexible dielectric layer covering the CMOS circuit layer, formed on the CMOS circuit substrate a first metal connection layer and planarization treatment is performed on the first metal connection layer, and the first metal connection layer is connected to the drain of the MOS transistor of the CMOS circuit; 2) forming a first metal transition layer on the first metal connection layer; 3) forming a fixed magnetic layer on the first metal transition layer, and the fixed magnetic layer is a two-dimensional magnetic material layer; 4) forming a tunneling layer on the fixed magnetic layer, where the tunneling layer is a two-dimensional insulating material layer; 5) depositing a free magnetic layer on the tunneling layer using an atomic layer deposition process, a chemical vapor deposition process or a thin film peel-transfer process, and the free magnetic layer is a two-dimensional magnetic material; 6) forming a second metal transition layer on the free magnetic layer; 7) forming a second metal connection layer on the second metal transition layer; 8) Pattern etching the second metal connection layer, the second metal transition layer, the tunnel isolation bottom layer, the free magnetic layer, the tunneling layer, the fixed magnetic layer, the tunnel isolation top layer, the first metal transition layer and the first A metal connection layer to form a magnetic tunnel junction device with a columnar structure. 2 . The method for fabricating a magnetic tunnel junction device based on a flexible substrate according to claim 1 , wherein the first metal transition layer has a flat surface, and the fixed magnetic layer is in transition with the first metal transition layer. 3 . The layers are tightly combined, and the Fermi energy level of the first metal transition layer is equal to or close to the Fermi energy level of the fixed magnetic layer, so as to reduce the contact resistance between the fixed magnetic layer and the first metal transition layer. 3 . The method for manufacturing a magnetic tunnel junction device based on a flexible substrate according to claim 1 , wherein the material of the fixed magnetic layer comprises one of CrGeTe ₃ and CrI ₃ , and the free magnetic layer is made of CrGeTe 3 and CrI 3 . The material includes one of CrGeTe ₃ and CrI ₃ . 4 . The method for fabricating a magnetic tunnel junction device based on a flexible substrate according to claim 1 , wherein the fixed magnetic layer comprises two-dimensional ferromagnetic material layers with a number of not less than 10 layers. 5 . 5 . The method for fabricating a magnetic tunnel junction device based on a flexible substrate according to claim 1 , wherein the free magnetic layer comprises two-dimensional ferromagnetic material layers in a quantity not greater than 5 layers. 6 . 6 . The method for manufacturing a magnetic tunnel junction device based on a flexible substrate according to claim 1 , wherein the two-dimensional insulating material layer comprises two-dimensional boron nitride, graphene fluoride and graphene oxide. 7 . a kind of. 7 . The method for fabricating a magnetic tunneling junction device based on a flexible substrate according to claim 1 , wherein the shape of the magnetic tunneling junction device comprises a cylindrical structure, and the diameter of the cylindrical structure ranges between between 10nm and 200nm. 8 . The method for fabricating a magnetic tunnel junction device based on a flexible substrate according to claim 1 , wherein the flexible substrate comprises polydimethylsiloxane, polyimide, polyethylene, poly One of propylene, polyethylene terephthalate and polyethylene terephthalate. 9 . The method for fabricating a magnetic tunnel junction device based on a flexible substrate according to claim 1 , wherein the surface roughness of the flexible dielectric layer is less than 0.2 nm. 10 . 10. A magnetic tunnel junction device based on a flexible substrate, comprising: a first metal connection layer, the first metal connection layer is formed on a CMOS circuit substrate, the CMOS circuit substrate includes a flexible substrate, a CMOS circuit layer on the flexible substrate, and a CMOS circuit layer covering the CMOS circuit layer the flexible dielectric layer, the first metal connection layer is connected to the drain of the MOS transistor of the CMOS circuit; a first metal transition layer formed on the first metal connection layer; a fixed magnetic layer formed on the first metal transition layer, and the fixed magnetic layer is a two-dimensional magnetic material layer; a tunneling layer, formed on the fixed magnetic layer, the tunneling layer is a two-dimensional insulating material layer; a free magnetic layer formed on the tunneling layer, and the free magnetic layer is a two-dimensional magnetic material; a second metal transition layer formed on the free magnetic layer; A second metal connection layer is formed on the second metal transition layer. 11 . The magnetic tunnel junction device based on a flexible substrate according to claim 10 , wherein the first metal transition layer has a flat surface, and the fixed magnetic layer is tightly combined with the first metal transition layer. 12 . , the Fermi energy level of the first metal transition layer is equal to or close to the Fermi energy level of the fixed magnetic layer, so as to reduce the contact resistance between the fixed magnetic layer and the first metal transition layer. 12 . The magnetic tunnel junction device based on a flexible substrate according to claim 10 , wherein the shape of the magnetic tunnel junction device comprises a cylindrical structure, and the diameter of the cylindrical structure ranges from 10 nm to 10 nm. 13 . between 200nm. 13. The magnetic tunnel junction device based on a flexible substrate according to claim 10, wherein the material of the fixed magnetic layer comprises one of CrGeTe ₃ and CrI ₃ , and the material of the free magnetic layer comprises One of CrGeTe ₃ and CrI ₃ . 14 . The magnetic tunnel junction device based on a flexible substrate according to claim 10 , wherein the fixed magnetic layer comprises two-dimensional ferromagnetic material layers and the number is not less than 10 layers. 15 . 15 . The magnetic tunnel junction device based on a flexible substrate according to claim 10 , wherein the free magnetic layer comprises two-dimensional ferromagnetic material layers and the number is not more than five layers. 16 . 16 . The magnetic tunnel junction device based on a flexible substrate according to claim 10 , wherein the two-dimensional insulating material layer comprises one of two-dimensional boron nitride, graphene fluoride and graphene oxide. 17 . . 17. The magnetic tunnel junction device based on a flexible substrate according to claim 10, wherein the flexible substrate comprises polydimethylsiloxane, polyimide, polyethylene, polypropylene, poly One of ethylene terephthalate and polyethylene terephthalate. 18 . The magnetic tunnel junction device based on a flexible substrate according to claim 10 , wherein the surface roughness of the flexible dielectric layer is less than 0.2 nm. 19 .

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