WO2022021169A1

WO2022021169A1 - Magnetic tunnel junction and storage unit

Info

Publication number: WO2022021169A1
Application number: PCT/CN2020/105660
Authority: WO
Inventors: 秦青; 周雪; 刘熹
Original assignee: 华为技术有限公司
Priority date: 2020-07-30
Filing date: 2020-07-30
Publication date: 2022-02-03
Also published as: CN115443548A

Abstract

A magnetic tunnel junction and a storage unit. The magnetic tunnel junction comprises a first electrode layer (210), a first fixed magnetic layer (220), a tunneling insulating layer (230), a free magnetic layer (240), a covering layer (250), a second fixed magnetic layer (260) and a second electrode layer (270), which are successively stacked in a longitudinal direction, wherein the first fixed magnetic layer (220) and the second fixed magnetic layer (260) respectively have a fixed magnetization direction, and the magnetization direction of the first fixed magnetic layer (220) has a longitudinal component, and a component, which is in the longitudinal direction, of the magnetization direction of the second fixed magnetic layer (260) is opposite to the component, in the longitudinal direction, of the magnetization direction of the first fixed magnetic layer (220); and the free magnetic layer (240) has vertical magnetic anisotropy. In this way, when a writing current passes the magnetic tunnel junction, the free magnetic layer (240) is subjected to two spin transfer moments which are in the same direction and are from the first fixed magnetic layer (220) and the second fixed magnetic layer (260), such that higher current efficiency is provided, a relatively small reverse current is required, the writing current of a device can be reduced, and writing power consumption is reduced.

Description

A magnetic tunnel junction and storage unit

technical field

The present application relates to the field of semiconductor technology, and in particular, to a magnetic tunnel junction and a memory cell.

Background technique

Magnetoresistive random access memory (MRAM) is a new type of non-volatile magnetic random access memory with non-volatile, unlimited read/write endurance, fast access time, low operating voltage It has the high-speed read and write capabilities of static random access memory (SRAM), and the high integration of dynamic random access memory (DRAM), which is compatible with complementary metal oxide semiconductors. semiconductor, CMOS) has good compatibility, so it has gradually received widespread attention.

The MRAM device can store information by changing the direction of magnetic polarization, and its basic storage unit includes a magnetic tunnel junction (MTJ), and the magnetic tunnel junction can include a fixed magnetic layer, a tunnel insulating layer on the fixed magnetic layer, and a magnetic tunnel junction on the fixed magnetic layer. The free magnetic layer on the tunneling insulating layer, wherein the magnetic properties of the fixed magnetic layer remain unchanged, and the magnetic properties of the free magnetic layer change with the writing current. When the magnetization directions of the fixed magnetic layer and the free magnetic layer are the same, the magnetic tunnel junction The resistance is the smallest. When the magnetization directions of the first magnetic layer and the second magnetic layer differ by 180 degrees, the resistance of the magnetic tunnel junction is the largest. Therefore, the data can be determined to be 0 or 1 through circuit design.

However, the current MRAM device has a large write current for changing the magnetic polarization direction of the free magnetic layer, which easily leads to large write power consumption.

SUMMARY OF THE INVENTION

In view of this, the first aspect of the present application provides a magnetic tunnel junction and a memory cell, which can reduce the writing current of the device and reduce the writing power consumption.

In a first aspect of the embodiments of the present application, a magnetic tunnel junction is provided, which includes a first electrode layer, a first fixed magnetic layer, a tunneling insulating layer, a free magnetic layer, a cover layer, and a second fixed magnetic layer that are stacked in sequence in the longitudinal direction. and the second electrode layer, wherein the first fixed magnetic layer and the second fixed magnetic layer each have a fixed magnetization direction, and the component of the magnetization direction of the second fixed magnetic layer in the longitudinal direction is in the direction of the magnetization of the first fixed magnetic layer. The component directions in the longitudinal direction are opposite, and the free magnetic layer has perpendicular magnetic anisotropy energy. That is, the magnetization direction of the free magnetic layer can be upward or downward, while the magnetization directions of the first pinned magnetic layer and the second pinned magnetic layer on both sides of the free magnetic layer have opposite components in the longitudinal direction. When the incoming current passes through the magnetic tunnel junction, the free magnetic layer will receive two spin transfer torques in the same direction from the first fixed magnetic layer and the second fixed magnetic layer. In terms of transfer torque, it has higher current efficiency, so the required switching current is smaller, so the write current of the device can be reduced, and the write power consumption can be reduced.

As a possible implementation manner, the second fixed magnetic layer includes a first perpendicular magnetization layer, and the first perpendicular magnetization layer has bulk perpendicular magnetic anisotropy energy.

In this embodiment of the present application, the second pinned magnetic layer may include a first perpendicular magnetization layer with bulk perpendicular magnetic anisotropy, so that the magnetization direction of the second pinned magnetic layer is related to its own material and has nothing to do with the material of the adjacent film layer , which can provide a reliable magnetic field and is suitable for more diverse scenarios.

As a possible implementation manner, the thickness of the first perpendicular magnetization layer is less than or equal to 10 nm.

In the embodiments of the present application, the first perpendicular magnetization layer may have bulk perpendicular magnetic anisotropy, so a smaller film thickness may be achieved, which is beneficial to reducing the size of the device.

As a possible implementation manner, the first perpendicular magnetization layer is a rare earth-transition metal material with bulk perpendicular magnetic anisotropy.

In the embodiments of the present application, the first perpendicular magnetization layer may be a rare earth-transition metal material, which has good bulk perpendicular magnetic anisotropy and can provide a reliable magnetic field.

As a possible implementation manner, the rare earth-transition metal material is at least one of the following materials: cobalt terbium, terbium cobalt iron, iron palladium boron, cobalt gadolinium, cobalt iron gadolinium, and cobalt chromium.

As a possible implementation manner, the second fixed magnetic layer includes a first perpendicular magnetization layer, the first perpendicular magnetization layer is a ferromagnetic metal material, and the longitudinal dimension of the first perpendicular magnetization layer is larger than the transverse dimension.

In this embodiment of the present application, the first perpendicular magnetization layer may be a ferromagnetic metal material, and its perpendicular magnetic anisotropy is provided by the structure of the first perpendicular magnetization layer. For example, the longitudinal dimension of the first perpendicular magnetization layer is larger than the lateral dimension, so that The longitudinal magnetization direction, and the thickness of the first perpendicular magnetization layer is relatively large, and can be used as a hard mask in the manufacturing process.

As a possible implementation manner, the ferromagnetic metal material includes at least one of the following materials: cobalt iron boron, iron boron, cobalt boron, cobalt, cobalt gadolinium, terbium cobalt iron, iron palladium boron, cobalt terbium, cobalt iron Gadolinium, cobalt chromium, Hasler alloys.

As a possible implementation manner, the second fixed magnetic layer further includes a horizontal magnetization layer between the first perpendicular magnetization layer and the second electrode layer, and the horizontal magnetization layer has a horizontal magnetic anisotropy energy , there is a ferromagnetic coupling between the horizontal magnetization layer and the first perpendicular magnetization layer.

In the embodiment of the present application, due to the existence of the horizontal magnetization layer, the magnetization direction of the second fixed magnetic layer has a certain angle with the vertical direction, so the current flowing through the second fixed magnetic layer has an inclined spin transfer torque, which reduces the incubation time. time, and increase the switching speed of the device.

As a possible implementation manner, the second fixed magnetic layer further includes a horizontal antiferromagnetic layer between the first perpendicular magnetization layer and the second electrode layer, and the horizontal antiferromagnetic layer has a horizontal magnetic Anisotropic energy, antiferromagnetic coupling between the horizontal antiferromagnetic layer and the first perpendicular magnetization layer.

In the embodiment of the present application, due to the existence of the horizontal antiferromagnetic layer, the magnetization direction of the second fixed magnetic layer has a certain angle with the vertical direction, so the current flowing through the second fixed magnetic layer has an inclined spin transfer torque, Decrease incubation time and increase device flipping speed.

As a possible implementation manner, the horizontal antiferromagnetic layer includes an antiferromagnetic material layer, or a plurality of antiferromagnetically coupled ferromagnetic material layers.

As a possible implementation manner, the second fixed magnetic layer further includes a second perpendicular magnetization layer between the first perpendicular magnetization layer and the free magnetic layer, and the second perpendicular magnetization layer has perpendicular magnetic Anisotropic performance.

In the embodiment of the present application, the second perpendicular magnetization layer is located on the side of the first perpendicular magnetization layer facing the free magnetic layer, thereby improving the spin transfer efficiency.

As a possible implementation manner, the second perpendicular magnetization layer is cobalt iron boron, cobalt boron, cobalt iron or iron boron.

As a possible implementation manner, the first fixed magnetic layer includes a pinned layer and a reference layer, the pinned layer is located between the first electrode layer and the reference layer, the reference layer and the pinned layer There is ferromagnetic coupling between the layers.

In the embodiment of the present application, the pinned layer is used to fix the magnetization direction of the reference layer, so that the reference layer has a fixed magnetization direction, so that the first fixed magnetic layer has a fixed magnetization direction, and there is a relatively small difference between the reference layer and the pinned layer. Strong ferromagnetic coupling, so the magnetization direction of the reference layer does not flip during current writing.

As a possible implementation manner, the pinning layer includes a first magnetic layer, a non-magnetic layer, and a second magnetic layer stacked in sequence, and the first magnetic layer and the second magnetic layer have antiferromagnetic coupling.

In the embodiment of the present application, the pinning layer may be an artificial antiferromagnetic structure, and this structure can reduce the stray field generated by the pinning layer.

As a possible implementation manner, the first magnetic layer and the second magnetic layer are at least one of the following materials: cobalt platinum multilayer film, cobalt palladium multilayer film, cobalt nickel multilayer film, iron platinum, Cobalt platinum, iron palladium, iron palladium boron, cobalt palladium, platinum manganese, palladium manganese, iron manganese, cobalt iron boron, iron boron, cobalt iron, cobalt boron; the material of the non-magnetic layer is at least one of the following materials: Iridium, Ruthenium, Copper, Chromium.

As a possible implementation manner, the pinned layer is a material layer with perpendicular magnetic anisotropy.

In this embodiment of the present application, the pinned layer may be a material layer with perpendicular magnetic anisotropy, without forming an artificial antiferromagnetic structure, so that the pinned layer and the second pinned magnetic layer on the other side of the free magnetic layer have The magnetization of the opposite magnetization components can be adjusted by adjusting the respective thicknesses, so that the stray field near the free magnetic layer can be zero.

As a possible implementation manner, each of the reference layer and the free magnetic layer is one of cobalt iron boron, cobalt boron, iron boron, and cobalt iron.

As a possible implementation manner, a structure conversion layer is formed between the pinning layer and the reference layer, and the structure conversion layer is at least one of the following materials: tantalum, titanium, titanium nitride, aluminum, Magnesium, titanium magnesium, tungsten, molybdenum.

In the embodiment of the present application, a structure conversion layer may also be formed between the pinning layer and the reference layer, and the structure conversion layer may provide a better growth plane for the upper film layer of the structure conversion layer.

As a possible implementation manner, the first electrode layer is a bottom electrode located on the bottom layer, and the second electrode layer is a top electrode located on the top layer; or, the first electrode layer is a top electrode located on the top layer, so The second electrode layer is a bottom electrode located at the bottom layer.

In the embodiments of the present application, one of the first electrode layer and the second electrode layer is a bottom electrode located at the bottom, and the other is a top electrode located at the top, so that the device can be adapted to more diverse device structures.

As a possible implementation manner, the magnetic tunnel junction further includes a seed layer;

When the first electrode layer is the bottom electrode, the seed layer is located between the first electrode layer and the first fixed magnetic layer; when the second electrode layer is the bottom electrode, the seed layer between the second electrode layer and the second fixed magnetic layer.

In the embodiments of the present application, a seed layer may be formed on the bottom electrode, so as to provide a better growth plane for the film layer thereon, so as to provide the quality of the film layer in the device, thereby improving the performance of the device.

As a possible implementation manner, the seed layer is at least one of the following materials: nickel-chromium, tantalum, tantalum nitride, platinum, palladium, ruthenium, iridium, and copper nitride.

As a possible implementation manner, each of the first electrode layer and the second electrode layer is at least one of titanium nitride, tantalum, platinum manganese, ruthenium, copper, tungsten, and aluminum.

As a possible implementation manner, the resistance of the cover layer is less than or equal to the tunneling insulating layer.

In the embodiment of the present application, the resistance of the capping layer is less than or equal to that of the tunneling insulating layer, thereby reducing the overall resistance in the magnetic tunnel junction while ensuring device performance.

As a possible implementation manner, the tunneling insulating layer is at least one of the following materials: magnesium oxide, magnesium gallium oxide, magnesium gadolinium oxide, titanium oxide, tantalum oxide, aluminum oxide, magnesium titanium oxide, strontium oxide, oxide barium, radium oxide, hafnium oxide; the coating material is at least one of the following materials: magnesium oxide, magnesium gallium oxide, magnesium gadolinium oxide, titanium oxide, tantalum oxide, aluminum oxide, magnesium titanium oxide, strontium oxide, barium oxide , radium oxide, hafnium oxide, tantalum, tungsten, platinum, palladium, molybdenum, ruthenium, titanium, titanium nitride, vanadium, magnesium, iridium.

In a second aspect of the embodiments of the present application, a memory cell is provided, including: a transistor, and the magnetic tunnel junction as provided in the first aspect of the embodiments of the present application, which is electrically connected to the transistor.

As a possible implementation manner, an interconnection line is formed between the transistor and the magnetic tunnel junction, and the transistor and the magnetic tunnel junction are electrically connected through the interconnection line.

As a possible implementation manner, the transistor includes a source electrode, a drain electrode and a gate electrode, and the magnetic tunnel junction is connected between the drain electrode and the bit line.

In a third aspect of the embodiments of the present application, a storage device is provided, including a storage controller and the storage unit provided in the third aspect of the embodiments of the present application, wherein the storage controller is configured to perform data reading on the storage unit Write.

As can be seen from the above technical solutions, the embodiments of the present application have the following advantages:

Embodiments of the present application provide a magnetic tunnel junction and a memory cell, wherein the magnetic tunnel junction includes a first electrode layer, a first fixed magnetic layer, a tunneling insulating layer, a free magnetic layer, a cover layer, and a second fixed magnetic layer that are stacked vertically in sequence and the second electrode layer, the first fixed magnetic layer and the second fixed magnetic layer each have a fixed magnetization direction, the magnetization direction of the first fixed magnetic layer has a longitudinal component, and the magnetization direction of the second fixed magnetic layer is in the longitudinal direction. The component is opposite to the longitudinal component of the magnetization direction of the first pinned magnetic layer, and the free magnetic layer has perpendicular magnetic anisotropy, that is, the first pinned magnetic layer and the second pinned magnetic layer are respectively located in the free magnetic layer. both sides, and have opposite magnetization components in the longitudinal direction, so that when the write current passes through the magnetic tunnel junction, the free magnetic layer will receive two same-direction spins from the first pinned magnetic layer and the second pinned magnetic layer The transfer torque has higher current efficiency than only the spin transfer torque from the first fixed magnetic layer, so the required flip current is smaller, so the write current of the device can be reduced, and the write power can be reduced. consumption.

Description of drawings

In order to clearly understand the specific embodiments of the present application, the accompanying drawings used in describing the specific embodiments of the present application will be briefly described below. Obviously, these drawings are only some embodiments of the present application.

1 is a schematic structural diagram of a basic storage unit of an MRAM device provided by an embodiment of the present application;

2 is a schematic structural diagram of a magnetic tunnel junction;

FIG. 3 is a schematic structural diagram of a magnetic tunnel junction according to an embodiment of the present application;

FIG. 4 is a schematic structural diagram of another magnetic tunnel junction provided by an embodiment of the present application;

FIG. 5 is a schematic structural diagram of another magnetic tunnel junction according to an embodiment of the present application.

detailed description

The embodiments of the present application provide a magnetic tunnel junction and a memory cell, which can reduce the writing current of the device and reduce the writing power consumption.

The terms "first", "second", "third", "fourth", etc. (if any) in the description and claims of this application and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It is to be understood that data so used may be interchanged under appropriate circumstances so that the embodiments described herein can be practiced in sequences other than those illustrated or described herein. Furthermore, the terms "comprising" and "having" and any variations thereof, are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those expressly listed Rather, those steps or units may include other steps or units not expressly listed or inherent to these processes, methods, products or devices.

The present application will be described in detail with reference to the schematic diagrams. When describing the embodiments of the present application in detail, for the convenience of explanation, the cross-sectional views showing the device structure will not be partially enlarged according to the general scale, and the schematic diagrams are only examples, which should not limit the application here. scope of protection. In addition, the three-dimensional spatial dimensions of length, width and depth should be included in the actual production.

The basic storage unit of the MRAM device may include a magnetic tunnel junction and a transistor, the magnetic tunnel junction and the transistor may be connected by interconnecting wires, and the transistor and the magnetic tunnel junction may also be connected with writing and reading wires respectively. Specifically, referring to FIG. 1 , which is a schematic structural diagram of a basic memory cell of an MRAM device provided by an embodiment of the present application, the transistor may include a source electrode 101 , a drain electrode 103 and a gate electrode 102 , and the connection between writing and reading is The lines may include a source line 300, a word line 200 and a bit line 400, wherein the source 101 of the transistor may be connected to the source line 300 through the interconnection line 30, and the gate 102 may be The word line 200 is connected to the word line 200 through the interconnect line 20, and the drain 103 is connected to the bit line 400 through the interconnect line 40 and the magnetic tunnel junction (MTJ) 500. The interconnect lines 30, 20, 40 may include vias or metal wires , and may also include connection pads and the like, for example, the lower electrode of the magnetic tunnel junction is connected to the drain 103 of the transistor through the through hole and the connection pad. Writing and reading of basic memory cells can be performed by the voltages of the source line 300 , the word line 200 and the bit line 300 of the transistors.

Referring to FIG. 2 , which is a schematic structural diagram of a magnetic tunnel junction, the magnetic tunnel junction may include a bottom electrode 110 , a fixed magnetic layer 111 , a tunneling insulating layer 112 , a free magnetic layer 113 and a top electrode 114 stacked in sequence, wherein, The magnetism of the fixed magnetic layer 111 does not change, and the magnetic polarization direction of the free magnetic layer 113 changes with the writing current. When the magnetization directions of the fixed magnetic layer 111 and the free magnetic layer 113 are the same, the resistance of the magnetic tunnel junction is the smallest. When the magnetization directions of the magnetic layer 111 and the free magnetic layer 113 differ by 180 degrees, the resistance of the magnetic tunnel junction is the largest. Therefore, the data can be determined to be 0 or 1 through circuit design.

For example, for spin transfer torque magnetic random access memory (STT-MRAM), its magnetic tunnel junction can be based on cobalt iron boron alloy/magnesium oxide (CoFeB/MgO, CoFeB/MgO) system, that is, free The magnetic layer 113 and the fixed magnetic layer 111 both comprise cobalt-iron-boron alloy, the tunneling insulating layer 112 is MgO, and the system can provide perpendicular magnetic anisotropy (PMA). There can be an upward or downward magnetization direction. Referring to FIG. 2 , the magnetization direction of the fixed magnetic layer 111 is upward, which can be indicated by the lines with arrows on the left side of the fixed magnetic layer 111 . The magnetization of the free magnetic layer 113 can be adjusted to be upward or downward according to the writing current. It is indicated by the arrowed line on the left side of the free magnetic layer 113 .

In practical storage applications, the magnetic direction of the free magnetic layer 113 only changes with the direction of the writing current. When the written information is different from the original stored information, the magnetic direction of the free magnetic layer 113 is reversed by 180 degrees, while the magnetic direction of the free magnetic layer 113 is reversed by 180 degrees during reading The magnetic direction of the free magnetic layer 113 does not change when there is no operation. The critical write current I _c of the MRAM device is proportional to the magnetic damping α of the free magnetic layer 113 , the amount of electron charge e and the energy barrier E of the free magnetic layer 113 flipping, and is proportional to the spin transfer efficiency g of the device (θ _m ) is inversely proportional, that is, the critical write current I _c can be expressed by the following formula:

Therefore, the device often requires a large write current, which easily leads to large write power consumption, and due to repeated writing, the current needs to pass through the magnetic tunnel junction, and the large write current may cause the breakdown of the magnetic tunnel junction. And cause permanent damage, can not meet the actual needs.

Based on the above technical problems, the embodiments of the present application provide a magnetic tunnel junction and a memory cell, wherein the magnetic tunnel junction includes a first electrode layer, a first fixed magnetic layer, a tunneling insulating layer, a free magnetic layer, a cover layer, a first electrode layer, a first fixed magnetic layer, a tunneling insulating layer, a free magnetic layer, layer, the second fixed magnetic layer and the second electrode layer, the first fixed magnetic layer and the second fixed magnetic layer each have a fixed magnetization direction, and the component of the magnetization direction of the second fixed magnetic layer in the longitudinal direction is the same as that of the first fixed magnetic layer. The component directions of the magnetization directions of the layers in the longitudinal direction are opposite, and the free magnetic layer has perpendicular magnetic anisotropy, that is, the first pinned magnetic layer and the second pinned magnetic layer are located on both sides of the free magnetic layer, and are in the longitudinal direction. It has opposite magnetization components on it, so that when the write current passes through the magnetic tunnel junction, the free magnetic layer will receive two spin transfer torques in the same direction from the first pinned magnetic layer and the second pinned magnetic layer, compared to In terms of only receiving the spin transfer torque from the first fixed magnetic layer, it has higher spin transfer efficiency and higher current efficiency, so the required switching current is smaller, so the write current of the device can be reduced, and the write current can be reduced. input power consumption.

In order to make the above objects, features and advantages of the present application more clearly understood, the specific embodiments of the present application will be described in detail below with reference to the accompanying drawings.

Referring to FIG. 3, which is a schematic structural diagram of a magnetic tunnel junction provided by an embodiment of the present application, the magnetic tunnel junction may include a first electrode layer 210, a first fixed magnetic layer 220, a tunneling insulating layer 230, The free magnetic layer 240 , the capping layer 250 , the second fixed magnetic layer 260 and the second electrode layer 270 .

Wherein, the first electrode layer 210 and the second electrode layer 270 may be respectively connected with the semiconductor device, so that the magnetic tunnel junction is applied with a voltage to form a write current, a read current and the like through the magnetic tunnel junction. The first electrode layer 210 and the second electrode layer 270 have a conductive function, and can be materials with good electrical conductivity, metals, or other conductor materials, such as titanium nitride, tantalum, platinum manganese, ruthenium, copper , at least one of tungsten or aluminum. The materials of the first electrode layer 210 and the second electrode layer 270 may be the same or different.

One of the first electrode layer 210 and the second electrode layer 270 is a bottom electrode at the bottom, and the other is a top electrode at the top. Specifically, the first electrode layer 210 may be the bottom electrode, and the second electrode layer 270 may be the top electrode, and the magnetic tunnel junction may include the first electrode layer 210, the first fixed magnetic layer 220, and the tunneling insulating layer in order from bottom to top. 230, the free magnetic layer 240, the cover layer 250, the second fixed magnetic layer 260 and the second electrode layer 270, as shown in FIG. 3; or, the first electrode layer 210 is the top electrode, and the second electrode layer 270 is the bottom electrode, That is, the magnetic tunnel junction may include the second electrode layer 270 , the second fixed magnetic layer 260 , the capping layer 250 , the free magnetic layer 240 , the tunneling insulating layer 230 , the first fixed magnetic layer 220 , and the first electrode layer in order from top to bottom. 210 , referring to FIG. 4 , which is a schematic structural diagram of another magnetic tunnel junction according to an embodiment of the present application. That is to say, the first pinned magnetic layer 220 and the second pinned magnetic layer 260 are located on both sides of the free magnetic layer 240. When the first pinned magnetic layer 220 is located under the free magnetic layer 240, the second pinned magnetic layer 260 is located on the free magnetic layer 240. Above the layer 240 , when the first pinned magnetic layer 220 is positioned above the free magnetic layer 240 , the second pinned magnetic layer 260 is positioned below the free magnetic layer 240 .

In the embodiment of the present application, in order to improve the quality of the film layer on the bottom electrode, a seed layer may be formed on the bottom electrode, so as to provide a better growth plane for the film layer thereon. For example, when the first electrode layer 210 is the bottom electrode, a seed layer 211 may be formed between the first electrode layer 210 and the first fixed magnetic layer 220, thereby improving the film quality of the first fixed magnetic layer 220. Referring to FIG. 5, A schematic structural diagram of another magnetic tunnel junction provided by the embodiment of the present application; when the second electrode layer 270 is the bottom electrode, a seed layer (not shown in the figure) may be formed between the second electrode layer 270 and the second fixed magnetic layer 260 out), thereby improving the film quality of the second fixed magnetic layer. The material of the seed layer may be at least one of the following materials: tantalum (Ta), titanium nitride (TiN), platinum (Pt), palladium (Pd), ruthenium (Ru), iridium (Ir), nickel chromium (NiCr) , copper nitride (CuN).

The first fixed magnetic layer 220 has a fixed magnetization direction, specifically, the magnetization direction may have a longitudinal component. For example, the first fixed magnetic layer 220 includes a film layer with perpendicular magnetic anisotropy (PMA), so it also has perpendicular magnetic anisotropy, and the magnetization direction of the film with perpendicular magnetic anisotropy Perpendicular to the film surface, for example, when the first pinned magnetic layer 220 is a vertically stacked film extending horizontally, its magnetization direction is perpendicular to the surface of the first pinned magnetic layer 220 , which may be vertically upward or vertically downward. In addition, the first fixed magnetic layer 220 includes a film layer with perpendicular magnetic anisotropy and a film with horizontal magnetic anisotropy, and the magnetization directions thereof may be inclined upward or downward.

In this embodiment of the present application, the first pinned magnetic layer 220 may include a pinned layer 221 and a reference layer 223, wherein the pinned layer 221 is used to fix the magnetization direction of the reference layer 223, so that the reference layer 223 has a fixed magnetization direction, thereby The first fixed magnetic layer 220 has a fixed magnetization direction, and there is strong ferromagnetic coupling between the reference layer 221 and the pinned layer 223, so the magnetization direction of the reference layer 223 does not reverse during current writing. The pinning layer 221 may be located between the first electrode layer 210 and the reference layer 223 .

As a possible implementation manner, the pinning layer 221 can be an artificial antiferromagnetic structure, and this structure can reduce the stray field generated by the pinning layer 221 . Specifically, the pinning layer 221 may include a first magnetic layer, a non-magnetic layer, and a second magnetic layer thus stacked, and the first magnetic layer and the second magnetic layer have antiferromagnetic coupling. When the first fixed magnetic layer has perpendicular magnetic anisotropy, the first magnetic layer and the second magnetic layer may also have magnetization directions perpendicular to the surface of their own film layers. Specifically, the first magnetic layer and the second magnetic layer are at least one of the following materials: cobalt platinum (Co/Pt) multilayer film, cobalt palladium (Co/Pd) multilayer film, cobalt nickel (Co/Ni) multilayer film Layer film, iron platinum (FePt), cobalt platinum (CoPt), iron palladium (FePd), iron palladium boron (FePdB), cobalt palladium (CoPd), platinum manganese (PtMn), palladium manganese (PdMn), iron manganese (FeMn) ), cobalt iron boron (CoFeB), iron boron (FeB), cobalt iron (CoFe), cobalt boron (CoB), etc.; the material of the non-magnetic layer is at least one of the following materials: iridium (Ir), ruthenium (Ru) , copper (Cu), chromium (Cr), etc.

As another possible implementation manner, the pinned layer 221 may be a material layer with perpendicular magnetic anisotropy, without forming an artificial antiferromagnetic structure, so that the pinned layer 221 and the layer located on the other side of the free magnetic layer 240 The second fixed magnetic layer 260 has opposite magnetization components, and the magnetization strengths of the two are adjusted by adjusting the respective thicknesses, so that the stray field near the free magnetic layer 240 can be zero.

The magnetization direction of the reference layer 223 is fixed by the pinned layer 221, so it can have a fixed magnetization direction. For example, the reference layer 223 can have perpendicular magnetic anisotropy, and its magnetization direction can be vertical to the surface of the reference layer 223, vertical upward or vertical to the reference layer. The surface of 223 is longitudinally downward, of course, its magnetization direction can also be at a certain angle with the longitudinal direction, that is, the magnetization direction is obliquely upward or obliquely downward. The reference layer 223 may be cobalt iron boron (CoFeB), iron boron (FeB), cobalt iron (CoFe) or cobalt boron (CoB), etc., that is, the reference layer 223 may be represented as (Co _x Fe _1-x ) _1-y B _y structure, where x and y are bounded between 0-0.50. The thickness of the reference layer 223 may be in the range of 0.1-5 nm, may be a doped material, may be a single-layer thin film structure, or may be a multi-layer thin film structure.

A structure conversion layer 222 may also be formed between the pinning layer 221 and the reference layer 223. The structure conversion layer 222 may provide a better growth plane for the upper film layer of the structure conversion layer 222. For example, the reference layer 223 is located above the pinning layer 221. When the structure conversion layer 222 is located above the reference layer 222, the structure conversion layer 222 can provide a better growth plane for the reference layer 223, thereby improving the film formation quality of the reference layer 223. For example, when the pinning layer 221 is located above the reference layer 222, the structure conversion layer 222 can be the pinning layer 221. A better growth plane is provided, thereby improving the film formation quality of the pinned layer 221 . The structural transformation layer 222 may be tantalum (Ta), titanium (Ti), titanium nitride (TiN), aluminum (Al), magnesium (Mg), titanium magnesium (TiMg), tungsten (W), molybdenum (Mo), and the like. At least one of the thickness can be less than or equal to 5nm.

The tunneling insulating layer 230 is formed between the first fixed magnetic layer 220 and the free magnetic layer 240 , showing a high resistance state, which is the main source of resistance in the magnetic tunnel junction. There is no electromagnetic coupling between the magnetic layer 220 and the free magnetic layer 240, and the tunneling insulating layer 230 can make the device have higher tunneling magnetoresistance (TMR). The tunneling insulating layer 230 may be a single-layer film or a multi-layer film, and its material may be at least one of the following materials: magnesium oxide (MgO), magnesium gallium oxide (MgGaO), magnesium gadolinium oxide (MgGdO), Titanium oxide (TiOx), tantalum oxide (TaOx), aluminum oxide (AlOx), magnesium titanium oxide (MgTiOx), strontium oxide (SrO), barium oxide (BaO), radium oxide (RaO), hafnium oxide (HfOx), etc.

The free magnetic layer 240 is a film layer that can change its magnetization direction with the writing current, and the free magnetic layer 240 may have perpendicular magnetic anisotropy. When the free magnetic layer 240 extends in the horizontal direction, its magnetization direction may be vertical. up or straight down. When the magnetization directions of the free magnetic layer 240 and the first fixed magnetic layer 220 are the same, the resistance of the magnetic tunnel junction is the smallest. maximum. For example, when the magnetization direction of the first fixed magnetic layer 220 is upward, if the magnetization direction of the free magnetic layer 240 is also upward, the resistance of the magnetic tunnel junction is the smallest. If the magnetization direction of the free magnetic layer 240 is downward, Then the resistance of the magnetic tunnel junction is the largest.

The materials of the free magnetic layer 240 and the reference layer 223 may be the same or different, and the free magnetic layer 240 may be cobalt iron boron (CoFeB), iron boron (FeB), cobalt iron (CoFe) or cobalt boron (CoB), etc. The free magnetic layer 240 can be represented as a (Co _x Fe _1-x ) _1- _y By structure, where x and y are bounded between 0 and 0.50, and the ratio here can be consistent with the reference layer 223 or with the reference layer 223 Differently, the values of x and _y in the (CoxFe1 _-x ₎ _1- yBy structure of the free magnetic layer 240 and the reference layer 223 determine the content of cobalt and iron therein. Generally speaking, the content of Fe/MgO is The interface perpendicular magnetic anisotropy energy is significantly larger than that of CoFe/MgO, so the value of x can be appropriately reduced to reduce the cobalt content, thereby improving the perpendicular magnetic anisotropy of the free magnetic layer 240 and the reference layer 223. can. However, considering the influence of magnetic damping and TMR value, the ratio of cobalt in the free magnetic layer 240 and the reference layer 223 cannot be too low, and x and y can be set between 0.15-0.30. The thickness of the free magnetic layer 240 can be in the range of 0.1-3 nm, and can be a doped material, a single-layer thin film structure, or a multi-layer thin film structure with magnetic coupling between the multilayer films.

The capping layer 250 is located between the free magnetic layer 240 and the second fixed magnetic layer 260, and is used to introduce an interface between the capping layer 250 and the free magnetic layer 240, thereby increasing the perpendicular magnetic anisotropy of the free magnetic layer 240 to achieve The purpose of increasing the data retention time. The resistance of the capping layer 250 may be less than or equal to the tunneling insulating layer 230, and may be consistent with the tunneling insulating layer 230, for example, may be at least one of the following materials: magnesium oxide (MgO), magnesium gallium oxide (MgGaO), magnesium gadolinium oxide (MgGdO), titanium oxide (TiOx), tantalum oxide (TaOx), aluminum oxide (AlOx), magnesium titanium oxide (MgTiOx), strontium oxide (SrO), barium oxide (BaO), radium oxide (RaO), hafnium oxide ( HfOx), etc., can also be metal materials, such as tantalum (Ta), tungsten (W), platinum (Pt), palladium (Pd), molybdenum (Mo), ruthenium (Ru), titanium (Ti), titanium nitride ( At least one of TiN), vanadium (V), magnesium (Mg), iridium (Ir) and the like. The cover layer 250 may be a single-layer film structure, or may be composed of a multi-layer film structure.

The second pinned magnetic layer 260 and the first pinned magnetic layer 220 are symmetrically disposed on both sides of the free material layer 240 , the second pinned magnetic layer 260 may have a fixed magnetization direction, and the magnetization direction of the second pinned magnetic layer 260 also has a longitudinal direction and the longitudinal component of the magnetization direction of the second pinned magnetic layer 260 is opposite to the longitudinal component of the magnetization direction of the first pinned magnetic layer 220. Specifically, the magnetization direction of the second pinned magnetic layer 260 is the same as The first fixed magnetic layer 220 may be anti-parallel, or may form a certain angle. Referring to FIG. 5 , the magnetization direction of the second pinned magnetic layer 260 is indicated by the arrowed line on the left side of the second pinned magnetic layer 260. When the vertical component of the magnetization direction of the first pinned magnetic layer 220 is upward, the The magnetization directions of the two fixed magnetic layers 260 may be vertically downward, or obliquely downward, that is, the component in the longitudinal direction is downward.

Since the component of the magnetization direction of the second pinned magnetic layer 260 in the longitudinal direction is opposite to the component of the magnetization direction of the first pinned magnetic layer 220 in the longitudinal direction, and the second pinned magnetic layer 260 and the first pinned magnetic layer 220 are disposed in the free On both sides of the magnetic layer, when the magnetic tunnel junction passes the write current, the first pinned magnetic layer 220 and the second pinned magnetic layer 260 can provide spin transfer torques in the same direction, and both spin transfer torques can promote The magnetization direction of the free magnetic layer 240 is reversed. Compared with only the first fixed magnetic layer 220, the embodiment of the present application can obtain higher spin transfer efficiency and higher current efficiency, and thus can reduce the writing current of the device. , reduce the power consumption of the device.

As a possible implementation manner, the second fixed magnetic layer 260 may include a first perpendicular magnetization layer 262, the first perpendicular magnetization layer 262 has perpendicular magnetic anisotropy, and the magnetization direction of the first fixed magnetic layer 220 is vertical When oriented, the magnetization direction of the first perpendicular magnetic layer 262 may be opposite to the magnetization direction of the first fixed magnetic layer 220 . For example, the magnetization direction of the first fixed magnetic layer 220 is upward, and the magnetization direction of the second fixed magnetic layer 262 is vertically downward.

Specifically, the first perpendicular magnetization layer 262 may have bulk perpendicular magnetic anisotropy (bulk PMA). The perpendicular anisotropy energy depends on the material properties of the first perpendicular magnetization layer 262 itself, and does not depend on the material of the film layer adjacent to it, and can provide a reliable magnetic field, which is suitable for more diverse scenarios. The first perpendicular magnetization layer 262 can be a thin film, and its thickness can be less than or equal to 10 nm, which can realize devices of smaller size. The first perpendicular magnetization layer 262 may be an amorphous material. Due to the amorphous nature of the first perpendicular magnetization layer 262, it is not sensitive to roughness and stress, which can reduce the effect of the first perpendicular magnetization layer 262 on the overall film layer. Influence of quality, specifically, the film layer formed on the first perpendicular magnetization layer 262 will not have problems such as dislocation caused by the difference in lattice constant between the first perpendicular magnetization layer 262 and the first perpendicular magnetization layer 262. Because of its amorphous properties, its surface is relatively flat, so whether it is above the bottom electrode or below the top electrode, it can form a relatively flat interface with other film layers, which is beneficial to obtain higher devices. performance.

The first perpendicular magnetization layer 262 can be, for example, a rare earth-transition metal (RE-TM) material with bulk perpendicular anisotropy. For example, the material of the first perpendicular magnetization layer 262 can be the following materials At least one of: cobalt terbium (CoTb), terbium cobalt iron (TbCoFe), iron palladium boron (FePdB), cobalt gadolinium (CoGd), cobalt iron gadolinium (CoFeGd), cobalt chromium (CoCr) and the like.

Since the coercive forces of the reference layer 223 and the first perpendicular magnetization layer 262 are different, the reference layer 223 and the first perpendicular magnetization layer 262 may be initialized by an external magnetic field so that they have opposite magnetization directions. Specifically, a magnetic field greater than the two coercive fields can be applied first, so that the magnetization directions of the two are the same, and then a magnetic field between the two coercive fields and opposite to the aforementioned magnetic field can be applied to make the softer The first perpendicular magnetization layer 262 is magnetized to the opposite direction to the reference layer 223 .

Specifically, the first perpendicular magnetization layer 262 can also be a ferromagnetic material, and its perpendicular magnetic anisotropy can be realized by the shape magnetic anisotropy. For example, the longitudinal dimension of the layer is larger than its transverse dimension, that is, its thickness is larger than its width. , thereby obtaining the magnetic anisotropy energy along the longitudinal direction. Specifically, for the first perpendicular magnetization layer 262 with a lateral dimension of 30 nm, the thickness thereof may be greater than 30 nm. The first perpendicular magnetization layer 262 may be any ferromagnetic material. As an example, the ferromagnetic material may include at least one of the following materials: cobalt iron boron (CoFeB), iron boron (FeB), cobalt boron (CoB), cobalt (Co ), cobalt gadolinium (CoGd), terbium cobalt iron (TbCoFe), iron palladium boron (FePdB), cobalt terbium (CoTb), cobalt iron gadolinium (CoFeGd), cobalt chromium (CoCr), Heusler alloy, etc. . When the first perpendicular magnetization layer 262 is made of a ferromagnetic material, the first perpendicular magnetization layer 262 may simultaneously serve as a part of a hard mask for etching the underlying film.

As another possible implementation manner, the second fixed magnetic layer 260 may include a first perpendicular magnetization layer 262 and a horizontal magnetization layer 263. The horizontal magnetization layer 263 has horizontal magnetic anisotropy, and the magnetization direction is parallel to the surface. When the layers are stacked vertically, the magnetization direction of the horizontal magnetization layer 263 is along the horizontal direction. The horizontal magnetization layer 263 is located between the first perpendicular magnetization layer 262 and the second electrode layer 270, that is, the horizontal magnetization layer 263 is located on the side of the first perpendicular magnetization layer 262 away from the free magnetic layer 240, the first perpendicular magnetization layer 262 and the horizontal magnetization There is ferromagnetic coupling between the layers 263. Due to the existence of the horizontal magnetization layer 263, the magnetization direction of the second fixed magnetic layer 260 has a certain angle with the vertical direction, so the current flowing through the second fixed magnetic layer 260 has an inclined self-direction. Rotation transfer torque reduces incubation time and increases device flipping speed. The material of the horizontal magnetization layer 263 may be at least one of the following materials: iridium manganese (IrMn), platinum manganese (PtMn), cobalt (Co), cobalt boron (CoB), nickel iron (NiFe), cobalt iron (CoFe), etc. .

As another possible implementation manner, the second fixed magnetic layer 260 may include a first perpendicular magnetization layer 262 and a horizontal antiferromagnetic layer, and the horizontal antiferromagnetic layer has antiferromagnetic properties and has a horizontal magnetic anisotropy energy, and its magnetization The direction is parallel to the surface, and the magnetization direction of the horizontal antiferromagnetic layer is along the horizontal direction when the individual layers are stacked vertically. The horizontal antiferromagnetic layer is located between the first perpendicular magnetization layer 262 and the second electrode layer 270, that is, the horizontal antiferromagnetic layer is located on the side of the first perpendicular magnetization layer 262 away from the free magnetic layer 240, and the first perpendicular magnetization layer 262 and There is antiferromagnetic coupling between the horizontal antiferromagnetic layers. Due to the existence of the horizontal antiferromagnetic layer, the magnetization direction of the second fixed magnetic layer 260 has a certain angle with the vertical direction. The current has a ramped spin transfer torque, reducing the incubation time and increasing the device flipping speed. The horizontal antiferromagnetic layer may be an antiferromagnetic material layer, or may include a plurality of antiferromagnetically coupled ferromagnetic material layers.

As another possible implementation manner, the second fixed magnetic layer 260 may include a first perpendicular magnetization layer 262 and a second perpendicular magnetization layer 261, the second perpendicular magnetization layer 261 has perpendicular magnetic anisotropy energy, and the first perpendicular magnetization layer 261 262 is located between the second perpendicular magnetization layer 261 and the second electrode layer 270, that is, the second perpendicular magnetization layer 261 is located on the side of the first perpendicular magnetization layer 262 facing the free magnetic layer 240, thereby improving the spin transfer efficiency. The material of the second perpendicular magnetization layer 261 may be at least one of cobalt iron boron (CoFeB), cobalt boron (CoB), cobalt iron (CoFe), and iron boron (FeB), and the thickness of the second perpendicular magnetization layer 261 may be less than or equal to 2nm.

As another possible implementation manner, the second fixed magnetic layer 260 may include a first perpendicular magnetization layer 262, a second perpendicular magnetization layer 261 and a horizontal magnetization layer 263, wherein the horizontal magnetization layer 263 is located at the first perpendicular magnetization layer 262 away from the free On one side of the magnetic layer 240, the second perpendicular magnetization layer 261 is located on the side of the first perpendicular magnetization layer 262 facing the free magnetic layer 240, and the magnetization direction of the second fixed magnetic layer 260 has a certain angle with the vertical direction, reducing the incubation time At the same time, it can also improve the spin transfer efficiency, thereby increasing the device flipping speed.

As another possible implementation manner, the second fixed magnetic layer 260 may include a first perpendicular magnetization layer 262 , a second perpendicular magnetization layer 261 and a horizontal antiferromagnetic layer, wherein the horizontal antiferromagnetic layer is located on the first perpendicular magnetization layer 262 On the side away from the free magnetic layer 240, the second perpendicular magnetization layer 261 is located on the side of the first perpendicular magnetization layer 262 facing the free magnetic layer 240, and the magnetization direction of the second fixed magnetic layer 260 has a certain angle with the vertical direction, which reduces the Incubation time can also provide spin transfer efficiency, thereby increasing device flipping speed.

In a specific implementation, the magnetic tunnel junction may include, from bottom to top, a first electrode layer 210 , a seed layer 211 , a pinning layer 221 , a structure conversion layer 222 , a reference layer 223 , a tunneling insulating layer 230 , a free magnetic layer 240 , and a capping layer 250, the second fixed magnetic layer 260 and the second electrode layer 270, or from bottom to top may include the second electrode layer 270, the seed layer, the capping layer 250, the free magnetic layer 240, the tunneling insulating layer 230, the reference layer 223, the structure The conversion layer 222, the pinning layer 221 and the first electrode layer 210, in addition, other intervening layers may be formed between these film layers to improve the lattice matching between the film layers, or for the barrier of different film layers layer, or used to cause interface effects, which will not be illustrated here.

An embodiment of the present application provides a magnetic tunnel junction, including a first electrode layer, a first pinned magnetic layer, a tunneling insulating layer, a free magnetic layer, a cover layer, a second pinned magnetic layer, and a second electrode layer that are stacked in sequence in the longitudinal direction , the first fixed magnetic layer and the second fixed magnetic layer each have a fixed magnetization direction, and the longitudinal component of the magnetization direction of the second fixed magnetic layer is opposite to the longitudinal component of the magnetization direction of the first fixed magnetic layer, The free magnetic layer has perpendicular magnetic anisotropy, that is to say, the first pinned magnetic layer and the second pinned magnetic layer are located on both sides of the free magnetic layer, respectively, and have opposite magnetization components in the longitudinal direction. When the current passes through the magnetic tunnel junction, the free magnetic layer will experience two spin transfer torques in the same direction from the first pinned magnetic layer and the second pinned magnetic layer, compared to only the spin transfer from the first pinned magnetic layer. In terms of torque, it has higher current efficiency, so the required switching current is smaller, so the write current of the device can be reduced, and the write power consumption can be reduced.

Embodiments of the present application further provide a memory cell, including: a transistor, and the magnetic tunnel junction electrically connected to the transistor. Wherein, an interconnection line is formed between the transistor and the magnetic tunnel junction, and the transistor and the magnetic tunnel junction are electrically connected through the interconnection line. Specifically, the transistor includes a source electrode, a drain electrode and a gate electrode, and the magnetic tunnel junction is connected between the drain electrode and the bit line. In addition, the source of the transistor may be connected to the source line, and the gate may be connected to the word line.

An embodiment of the present application further provides a storage device, including a storage controller and the above storage unit, wherein the storage controller is configured to read and write data to the storage unit. Specifically, the memory controller may provide a write voltage or a read voltage to the memory cells, so as to write data to the memory cells, or read data in the memory cells. For example, the memory controller can control the voltages of the word lines, bit lines and source lines to control the operating state of the transistors to provide a write voltage or a read voltage between the upper and lower electrodes of the magnetic tunnel junction. Among them, the write voltage will generate a write current through the magnetic tunnel junction, which may cause the magnetization direction of the free magnetic layer in the magnetic tunnel junction to be reversed to achieve a change in the storage state, while the read voltage will generate a read through the magnetic tunnel junction. Taking the current, the magnitude of the read current reflects the resistance of the magnetic tunnel junction, so it can reflect whether the magnetization direction of the free magnetic layer is the same or opposite to that of the first fixed magnetic layer, thereby reflecting the storage state.

The "first" in the names such as "first fixed magnetic layer", "first perpendicular magnetization layer", "first electrode layer" mentioned in the embodiments of this application is only used for name identification, and does not represent the order of number one. The same rule applies to "second" etc.

Each embodiment in this specification is described in a progressive manner, and the same and similar parts between the various embodiments may be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the embodiments of the storage unit and the storage device, since they are basically similar to the structural embodiments of the magnetic tunnel junction, the description is relatively simple, and reference may be made to some descriptions of the structural embodiments for related parts.

The above is a specific implementation manner of the application. It should be understood that the above-mentioned embodiments are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the above-mentioned embodiments, those of ordinary skill in the art should understand that: it can still be used for The technical solutions described in the foregoing embodiments are modified, or some technical features thereof are equivalently replaced; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

A magnetic tunnel junction, comprising:

A first electrode layer, a first fixed magnetic layer, a tunneling insulating layer, a free magnetic layer, a cover layer, a second fixed magnetic layer, and a second electrode layer stacked in sequence in the longitudinal direction;

The first fixed magnetic layer and the second fixed magnetic layer each have a fixed magnetization direction, and the component of the magnetization direction of the second fixed magnetic layer in the longitudinal direction is in the same direction as the magnetization direction of the first fixed magnetic layer. The directions of the components in the longitudinal direction are opposite; the free magnetic layer has perpendicular magnetic anisotropy energy.
The magnetic tunnel junction according to claim 1, wherein the second fixed magnetic layer comprises a first perpendicular magnetization layer, and the first perpendicular magnetization layer has bulk perpendicular magnetic anisotropy energy.
The magnetic tunnel junction according to claim 2, wherein the first perpendicular magnetization layer is a rare earth-transition metal material with bulk perpendicular magnetic anisotropy.
The magnetic tunnel junction according to claim 3, wherein the rare earth-transition metal material is at least one of the following materials: cobalt terbium, terbium cobalt iron, iron palladium boron, cobalt gadolinium, cobalt iron gadolinium, cobalt chromium .
The magnetic tunnel junction according to claim 1, wherein the second fixed magnetic layer comprises a first perpendicular magnetization layer, the first perpendicular magnetization layer is a ferromagnetic metal material, and the first perpendicular magnetization layer has a The vertical size is larger than the horizontal size.
The magnetic tunnel junction according to claim 5, wherein the ferromagnetic metal material comprises at least one of the following materials: cobalt iron boron, iron boron, cobalt boron, cobalt, cobalt gadolinium, terbium cobalt iron, iron palladium Boron, cobalt terbium, cobalt iron gadolinium, cobalt chromium, Hasler alloy.
The magnetic tunnel junction according to any one of claims 2-6, wherein the second fixed magnetic layer further comprises a horizontal magnetization layer between the first perpendicular magnetization layer and the second electrode layer, The horizontal magnetization layer has horizontal magnetic anisotropy energy, and there is ferromagnetic coupling between the horizontal magnetization layer and the first perpendicular magnetization layer.
The magnetic tunnel junction according to any one of claims 2-6, wherein the second fixed magnetic layer further comprises a horizontal antiferromagnetic layer between the first perpendicular magnetization layer and the second electrode layer layer, the horizontal antiferromagnetic layer has horizontal magnetic anisotropy, and there is antiferromagnetic coupling between the horizontal antiferromagnetic layer and the first perpendicular magnetization layer.
The magnetic tunnel junction according to claim 8, wherein the horizontal antiferromagnetic layer comprises an antiferromagnetic material layer, or a plurality of antiferromagnetically coupled ferromagnetic material layers.
The magnetic tunnel junction according to any one of claims 2-9, wherein the second fixed magnetic layer further comprises a second perpendicular magnetization layer between the first perpendicular magnetization layer and the free magnetic layer, The second perpendicular magnetization layer has perpendicular magnetic anisotropy energy.
The magnetic tunnel junction according to claim 10, wherein the second perpendicular magnetization layer is cobalt iron boron, cobalt boron, cobalt iron or iron boron.
The magnetic tunnel junction according to any one of claims 1-11, wherein the first pinned magnetic layer comprises a pinned layer and a reference layer, and the pinned layer is located on the first electrode layer and the reference layer There is ferromagnetic coupling between the reference layer and the pinned layer.
The magnetic tunnel junction according to claim 12, wherein the pinned layer comprises a first magnetic layer, a non-magnetic layer, and a second magnetic layer stacked in sequence, the first magnetic layer and the second magnetic layer The layers have antiferromagnetic coupling.
The magnetic tunnel junction according to claim 13, wherein the first magnetic layer and the second magnetic layer are at least one of the following materials: cobalt platinum multilayer film, cobalt palladium multilayer film, cobalt nickel multilayer film Multilayer film, iron platinum, cobalt platinum, iron palladium, iron palladium boron, cobalt palladium, platinum manganese, palladium manganese, iron manganese, cobalt iron boron, iron boron, cobalt iron, cobalt boron; the material of the non-magnetic layer is At least one of the following materials: iridium, ruthenium, copper, chromium.
The magnetic tunnel junction according to claim 14, wherein the reference layer and the free magnetic layer are each one of cobalt iron boron, cobalt boron, iron boron, and cobalt iron.
The magnetic tunnel junction according to claim 12, wherein the pinned layer is a material layer with perpendicular magnetic anisotropy.
The magnetic tunnel junction according to any one of claims 11-16, wherein a structure conversion layer is formed between the pinning layer and the reference layer, and the structure conversion layer is at least one of the following materials Species: tantalum, titanium, titanium nitride, aluminum, magnesium, titanium magnesium, tungsten, molybdenum.
The magnetic tunnel junction according to any one of claims 1-17, wherein the first electrode layer is a bottom electrode located on the bottom layer, and the second electrode layer is a top electrode located on the top layer; or, the The first electrode layer is a top electrode on the top layer, and the second electrode layer is a bottom electrode on the bottom layer.
The magnetic tunnel junction of claim 18, further comprising a seed layer;

When the first electrode layer is the bottom electrode, the seed layer is located between the first electrode layer and the first fixed magnetic layer; when the second electrode layer is the bottom electrode, the seed layer between the second electrode layer and the second fixed magnetic layer.
The magnetic tunnel junction according to claim 19, wherein the seed layer is at least one of the following materials: nickel-chromium, tantalum, tantalum nitride, platinum, palladium, ruthenium, iridium, and copper nitride.
The magnetic tunnel junction according to any one of claims 1-20, wherein the first electrode layer and the second electrode layer are titanium nitride, tantalum, platinum manganese, ruthenium, copper, tungsten, At least one of aluminum.
The magnetic tunnel junction according to any one of claims 1-21, wherein the resistance of the capping layer is less than or equal to that of the tunneling insulating layer.
The magnetic tunnel junction according to claim 22, wherein the tunnel insulating layer is at least one of the following materials: magnesium oxide, magnesium gallium oxide, magnesium gadolinium oxide, titanium oxide, tantalum oxide, aluminum oxide, oxide Magnesium titanium, strontium oxide, barium oxide, radium oxide, hafnium oxide; the coating material is at least one of the following materials: magnesium oxide, magnesium gallium oxide, magnesium gadolinium oxide, titanium oxide, tantalum oxide, aluminum oxide, magnesium oxide Titanium, strontium oxide, barium oxide, radium oxide, hafnium oxide, tantalum, tungsten, platinum, palladium, molybdenum, ruthenium, titanium, titanium nitride, vanadium, magnesium, iridium.
A memory cell, comprising: a transistor, and the magnetic tunnel junction according to any one of claims 1-23, which is electrically connected to the transistor.
A storage device, comprising a storage controller and the storage unit according to claim 24, wherein the storage controller is configured to read and write data to the storage unit.