Storage unit and forming method thereof, data writing method and memory

Abstract

The invention discloses a storage unit and a forming method thereof, a data writing method and a memory. The storage unit comprises a substrate; the heavy metal layer, the magnetic tunnel junction layer and the top metal layer are sequentially located on the substrate; a first access port and a second access port are formed in the two sides, in the first preset direction, of the heavy metal layer correspondingly, and a third access port is formed in the top metal layer in the second preset direction; the first preset direction is parallel to the direction of the contact surface of the heavy metal layer and the substrate, and the first preset direction is perpendicular to the second preset direction; the magnetic tunnel junction layer comprises a free layer; wherein the first access port and the second access port are used for inputting a first current into the heavy metal layer, the third access port is used for inputting a second current into the top metal layer, and the first current and the second current are used for turning the spinning direction of the free layer. According to the invention, the data writing accuracy and writing speed of the storage unit are improved.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and in particular, to a storage unit, a method for forming the same, a method for writing data, and a memory. Background Art

[0002] Magnetoresistive Random Access Memory (MRAM), as a fast non-volatile memory, has replaced DRAM and SRAM and received increasing attention. The 10 ns time scale speed of MRAM is slower than that of SRAM but faster than that of DRAM. The write error rate of the current MRAM structure remains high, which limits its application in the storage field.

[0003] Therefore, improving the write speed of MRAM and reducing the write error rate are technical problems that need to be solved urgently. Summary of the Invention

[0004] The technical problem solved by the present invention is to provide a storage unit, a method for forming the same, a method for writing data, and a memory, which improve the accuracy and write speed of writing data into the storage unit.

[0005] To solve the above technical problem, the technical solution of the present application is as follows:

[0006] According to the first aspect of the embodiments of the present application, a storage unit is provided, including:

[0007] A substrate;

[0008] A heavy metal layer, a magnetic tunnel junction layer, and a top metal layer sequentially located on the substrate; the two sides of the heavy metal layer in a first preset direction are respectively provided with a first access port and a second access port, and the top metal layer is provided with a third access port in a second preset direction; the first preset direction is a direction parallel to the contact surface between the heavy metal layer and the substrate, and the first preset direction is perpendicular to the second preset direction; the magnetic tunnel junction layer includes a free layer;

[0009] Wherein, the first access port and the second access port are used to input a first current into the heavy metal layer, and the third access port is used to input a second current into the top metal layer, and the first current and the second current are used to flip the spin direction of the free layer.

[0010] According to the second aspect of the embodiments of the present application, a method for forming a storage unit is provided, and the method includes:

[0011] Providing a substrate;

[0012] Forming a heavy metal material layer on the substrate;

[0013] Form a magnetic tunnel junction material layer on the heavy metal material layer;

[0014] Form a top metal material layer on the magnetic tunnel junction material layer;

[0015] Etch the top metal material layer, the magnetic tunnel junction material layer, and the heavy metal material layer in sequence to form a top metal layer, a magnetic tunnel junction layer, and a heavy metal layer; the magnetic tunnel junction layer includes a free layer; on both sides of the heavy metal layer along a first preset direction, a first access port and a second access port are respectively arranged, and a third access port is arranged on the top metal layer along a second preset direction; the first preset direction is a direction parallel to the contact surface between the heavy metal layer and the substrate, and the first preset direction is perpendicular to the second preset direction;

[0016] Wherein, the first access port and the second access port are used to input a first current into the heavy metal layer, and the third access port is used to input a second current into the top metal layer, and the first current and the second current are used to flip the spin direction of the free layer.

[0017] According to the third aspect of the embodiments of the present application, a method for writing data of a storage unit is provided, and the data writing method includes:

[0018] Obtain the current resistance state and the data to be written of the storage unit;

[0019] Determine the target resistance state of the storage unit according to the data type corresponding to the data to be written;

[0020] According to the target resistance state and the current resistance state, input the first current in the target direction into the heavy metal layer through the first access port and the second access port; the first current is used to deflect the spin direction of the free layer by a preset angle;

[0021] Input a second current into the top metal layer through the third access port to flip the spin direction of the free layer and write the data to be written.

[0022] According to the fourth aspect of the embodiments of the present application, a memory is provided, and the memory includes the above storage unit.

[0023] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0024] The present invention provides a storage unit, comprising: a substrate; a heavy metal layer, a magnetic tunnel junction layer and a top metal layer that are sequentially located on the substrate; a first access port and a second access port are respectively arranged on two sides of the heavy metal layer along a first preset direction, and a third access port is arranged on the top metal layer along a second preset direction; the first preset direction is a direction parallel to the contact surface between the heavy metal layer and the substrate, and the first preset direction is perpendicular to the second preset direction; the magnetic tunnel junction layer includes a free layer; wherein, the first access port and the second access port are used to input a first current into the heavy metal layer, and the third access port is used to input a second current into the top metal layer, and the first current and the second current are used to flip the spin direction of the free layer. By providing a heavy metal layer and arranging two access ports at both ends of the heavy metal layer, the present invention facilitates controlling the direction of the first current input into the heavy metal layer, realizes fine-tuning the spin direction in the free layer, deflecting a preset angle, and then inputs a second current through the third access port in the top metal layer to realize a complete flip of the spin direction in the free layer. Since the free layer has deviated from the current spin direction and shifted a preset angle towards the target direction, the input voltage corresponding to the second current is reduced, the success rate and the flip speed of the free layer flip are improved, and thus the accuracy and the write speed of writing data in the storage unit are improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the present invention, the accompanying drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0026] Figure 1 is a schematic structural diagram of an MRAM unit in the prior art;

[0027] Figure 2 is Figure 1 the voltage-resistance curve of the corresponding MRAM unit;

[0028] Figure 3 is a schematic diagram of the spin direction change of the free layer in an MRAM unit in the prior art;

[0029] Figure 4 is Figure 3 the voltage-resistance curve during the spin direction change of the free layer in the MRAM unit;

[0030] Figure 5 is a schematic diagram of the spin direction change of the free layer in an MRAM unit under thermal fluctuations in the prior art;

[0031] Figure 6 is Figure 5 The time-spin direction curve corresponding to the free layer of the MRAM cell in

[0032] Figure 7 is a schematic structural diagram of a storage cell provided by an embodiment of the present invention;

[0033] Figure 8 is a flowchart of a method for forming a storage cell provided by an embodiment of the present invention;

[0034] Figure 9 is a flowchart of a method for writing data into a storage cell provided by an embodiment of the present invention;

[0035] Figure 10 is a schematic diagram of a method for writing data into a storage cell provided by an embodiment of the present invention Figure One ;

[0036] Figure 11 is a schematic diagram of a method for writing data into a storage cell provided by an embodiment of the present invention Figure Two ;

[0037] Figure 12 is a current-time curve diagram corresponding to the first current introduced into the heavy metal layer provided by an embodiment of the present invention;

[0038] Figure 13 is a current-time curve diagram corresponding to the second current introduced into the top metal layer provided by an embodiment of the present invention;

[0039] Figure 14 is a time-resistance curve diagram during the process of introducing the first current and the second current provided by an embodiment of the present invention;

[0040] Figure 15 is a time curve diagram for writing data corresponding to an initial spin angle of 0.15 rad provided by an embodiment of the present invention.

[0041] Figure 16 is a time curve diagram for writing data corresponding to an initial spin angle of 0.06 rad provided by an embodiment of the present invention.

[0042] Among them, the reference numerals in the figure correspond to: 10 - free layer, 20 - oxide layer, 30 - fixed layer, 40 - first port, 50 - second port, 61 - first access port, 62 - second access port, 63 - third access port, 70 - heavy metal layer, 80 - top metal layer, 90 - magnetic tunnel junction layer. Detailed implementation manners

[0043] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0044] As used herein, the term "one embodiment" or "embodiment" refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present application. In the description of the present application, it should be understood that relative spatial terms, such as "below...", "beneath", "lower", "above...", "upper", "front", "back", "above...", and the like, may be used herein for ease of description to describe the relationship of one element or feature to another (other) element or feature as illustrated in the figures. This is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the present application. Relative spatial terms are intended to cover different orientations in the use or operation of the device other than the orientation depicted in the figures. The device may be oriented in other ways (rotated 90 degrees or in other orientations), and the relative spatial descriptors used herein can be interpreted similarly.

[0045] The following disclosure provides many different embodiments or examples for implementing different features of the provided subject matter. Specific examples of components and configurations are described below to simplify the disclosure. Of course, these components and configurations are only examples and are not intended to be limiting. For example, in the following description, the formation of a first feature above or on a second feature may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features may be formed between the first and second features such that the first and second features are not in direct contact. In addition, the present disclosure may repeat reference numerals and / or letters in various examples. This repetition is for the purpose of simplicity and clarity, and does not in itself indicate the relationship between the various embodiments and / or configurations discussed.

[0046] In addition, the terms "first" and "second" are used only for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. Moreover, the terms "first", "second", etc. are used to distinguish similar objects and do not necessarily have to be used to describe a specific order or sequence. It should be understood that such data may be interchanged under appropriate circumstances so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein.

[0047] Now, the problems existing in the existing MRAM will be described with reference to the accompanying drawings.

[0048] The Spin Transfer Torque Magnetic Random Access Memory (STT-MRAM) has characteristics such as high read / write speed, high density, low power consumption, long data retention time, and high lifespan, and has immeasurable broad prospects. More notably, STT-MRAM can be developed based on the existing Complementary Metal Oxide Semiconductor (CMOS) manufacturing technology and process, and the difficulty of technological relay is relatively small. Thus, it can directly challenge the low cost of flash memory. Among them, the MRAM cell in STT-MRAM has resistance variability. Therefore, data information can be stored through its different resistance states.

[0049] The core part of the magnetic tunnel junction is a sandwich structure formed by sandwiching a tunneling barrier layer between two ferromagnetic metal layers. One ferromagnetic layer is called the reference layer or pinned layer, and its magnetization is fixed along the easy-axis direction; the other ferromagnetic layer is called the free layer. As Figure 1 shown, Figure 1 shows a schematic structural diagram of an MRAM cell in the prior art. The MRAM cell includes a free layer 10, an oxide layer 20, and a fixed layer 30. Among them, a first port 40 is provided on the fixed layer 30, and the first port 40 is used to connect the lead T1' to input current. A second port 50 is provided on the free layer 10, and the second port 50 is used to connect the lead T2' to input current; different relative magnetization directions of the ferromagnetic metals will exhibit different resistances, and information "0" and "1" can be stored. As Figure 2 shown, Figure 2 is Figure 1 the voltage-resistance curve of the corresponding MRAM cell. When in the high-resistance state, the written data is 1, and when in the low-resistance state, the written data is 0.

[0050] As Figure 3 shown, Figure 3 is a schematic diagram of the change in the spin direction of the free layer in an MRAM cell in the prior art. The initial state of the torque of the free layer 10 in the MRAM is non-linear with the initial state of the torque of the fixed layer 30, and the feeding current in the MRAM can generate a torque that can switch the spin. As Figure 4 shown, Figure 4 is Figure 3The voltage-resistance curve during the change of the spin direction of the free layer in the MRAM cell. From this, it can be determined that the room-temperature data shows that the write time is about 100 ns, which is much slower than that of Static Random-Access Memory (SRAM).

[0051] As Figure 5 shown, Figure 5 FIG. is a schematic diagram of the change in the spin direction of the free layer in the MRAM cell in the prior art under thermal fluctuations. The initial angle of the free layer 10 is determined by thermal fluctuations and shows random diffusion. If the angle is very small, the spin direction cannot be switched under the same conditions, and the spin direction is a random probability event that cannot be controlled, resulting in a relatively high error rate and a relatively slow write speed when writing data to the MRAM cell. As Figure 6 shown, Figure 6 is Figure 5 the time-spin direction curve corresponding to the free layer of the MRAM cell in FIG. The spin angle of the initial state of the free layer 10 is 0.06 rad. It can be seen that after 30 nanoseconds (ns), the free layer 10 still cannot achieve the flip of the spin direction, which will result in errors in data writing.

[0052] In order to solve the technical problems of relatively high error rate and relatively slow write speed when writing data to the MRAM cell in the prior art, the embodiments of the present application provide a storage cell, a method for forming a storage cell, a method for writing data, and a memory to solve the above problems existing in the prior art.

[0053] Figure 7 FIG. is a schematic structural diagram of a storage cell shown according to an exemplary embodiment. Please refer to Figure 7 , the storage cell may include:

[0054] a substrate;

[0055] a heavy metal layer 70, a magnetic tunnel junction layer 90, and a top metal layer 80 that are sequentially located on the substrate; a first access port 61 and a second access port 62 are respectively provided on both sides of the heavy metal layer 70 in a first preset direction, and a third access port 63 is provided on the top metal layer 80 in a second preset direction; the first preset direction is a direction parallel to the contact surface between the heavy metal layer 70 and the substrate, and the first preset direction is perpendicular to the second preset direction; the magnetic tunnel junction layer 90 includes a free layer 10;

[0056] wherein, the first access port 61 and the second access port 62 are used to input a first current into the heavy metal layer 70, and the third access port 63 is used to input a second current into the top metal layer 80. The first current and the second current are used to flip the spin direction of the free layer 10.

[0057] In the embodiments of the present specification, a substrate may be provided. The substrate serves as a carrier for various structures such as the heavy metal layer 70, the magnetic tunnel junction layer 90, and the top metal layer 80. The substrate may be a silicon substrate or a germanium substrate, etc. A CMOS device may be formed in the substrate, such as an NMOS transistor and / or a PMOS transistor, etc.; an isolation structure may also be formed in the substrate, and the isolation structure is a shallow trench isolation structure or a local oxidation of silicon (LOCOS) isolation structure. Similarly, a conductive member may also be formed in the substrate. The conductive member may be the gate, source, or drain of a transistor, or a metal interconnect structure electrically connected to the transistor, etc. Circuit structures such as word lines and bit lines may also be provided in the substrate. For example, the substrate sequentially includes a first interlayer insulating layer, a diffusion barrier layer, and a second interlayer insulating layer from top to bottom. Among them, the materials of the first interlayer insulating layer and the second interlayer insulating layer may be interlayer oxide insulating layers prepared from oxide insulating materials. Specifically, the first interlayer insulating layer and the second interlayer insulating layer may be prepared from oxide insulating materials such as silicon oxide and silicon oxynitride. The material of the diffusion barrier layer therein may be silicon nitride and other materials.

[0058] In the embodiments of the present specification, a first access port 61 and a second access port 62 are respectively provided on both sides of the heavy metal layer 70 along a first preset direction, and a third access port 63 is provided on the top metal layer 80 along a second preset direction; the first preset direction is a direction parallel to the contact surface between the heavy metal layer 70 and the substrate, and the first preset direction is perpendicular to the second preset direction; the first preset direction is a direction parallel to the contact surface between the heavy metal layer 70 and the substrate, and the first preset direction is perpendicular to the second preset direction; as Figure 7 shown, the contact surface between the heavy metal layer 70 and the substrate is located in the length direction of the heavy metal layer 70. The first preset direction may be parallel to the length direction of the heavy metal layer 70, and the second preset direction may be the height direction of the top metal layer 80. The magnetic tunnel junction layer 90 includes a free layer 10; among them, the first access port 61 and the second access port 62 are used to input a first current in a target direction into the heavy metal layer 70, and the third access port 63 is used to input a second current into the top metal layer 80. The first current and the second current are used to enter the free layer 10 to flip the spin direction of the free layer 10. The input directions of the first current and the second current are perpendicular to each other. The second current may be a direction perpendicular to the direction of the first current and towards the top metal layer 80, or a direction perpendicular to the direction of the first current and away from the top metal layer 80. The input directions of the first current and the second current are both in an adjustable state, and the directions of the two are always perpendicular to each other.

[0059] In the embodiments of this specification, as Figure 7 shown, a heavy metal layer 70 can be disposed below the magnetic tunnel junction layer 90, a top metal layer 80 can be disposed above the magnetic tunnel junction layer 90, and a first access port 61 and a second access port 62 can be respectively disposed at two ends of the heavy metal layer 70; and a third access port 63 can be disposed on the top metal layer 80; the first access port 61 is used to connect to a lead T1, the second access port 62 is used to connect to a lead T2, the leads T1 and T2 are used to control the direction of the input first current, and the third access port 63 is used to connect to a lead T3 to input a second current; wherein, the direction of the first current is perpendicular to the direction of the second current, and the first access port 61 and the second access port 62 can be used to control the direction of the current input into the heavy metal layer 70, so as to adjust the initial spin angle of the free layer 10; during the process of writing data into the storage unit, the spin direction of the electrons in the free layer 10 can be adjusted by adjusting the direction of the first current, so as to write different data. Exemplarily, according to the type of the written data, the direction of the first current input into the heavy metal layer 70 can be determined, and the current magnitude and the current input time can be further determined; the spin direction in the free layer 10 is offset from the current stable direction by a preset angle, and then a second current is input into the top metal layer 80 through the third access port 63, and after passing through the free layer 10, the second current can change the spin direction of the free layer 10, realizing the flip of the spin direction, and the flip process can realize the conversion of the storage unit from a high-resistance state to a low-resistance state or from a low-resistance state to a high-resistance state, so as to realize the update of the written data.

[0060] In the embodiments of this specification, the thickness of the heavy metal layer 70 is 5 - 100 nm, the thickness of the magnetic tunnel junction layer 90 is 3 - 7 nm, and the thickness of the top metal layer 80 is 20 - 100 nm.

[0061] In the embodiments of this specification, in order to ensure that by inputting a current into the heavy metal layer 70, the initial spin angle of the free layer 10 in the magnetic tunnel junction layer 90 can be quickly adjusted so that the initial spin angle meets the preset conditions, the thickness of the heavy metal layer 70 can be set to 5 - 100 nm, and the thickness of the magnetic tunnel junction layer 90 is 3 - 7 nm; in order to ensure that on the basis of the initial spin angle of the free layer 10, the spin direction in the free layer 10 can be quickly flipped, the thickness of the top metal layer 80 can be further set to 20 - 100 nm.

[0062] In the embodiments of this specification, by setting the respective thicknesses of the heavy metal layer 70, the magnetic tunnel junction layer 90, and the top metal layer 80, the quick flip of the spin direction in the free layer 10 can be ensured.

[0063] In the embodiments of the present specification, the length of the heavy metal layer 70 is 60 ± 5 nm, the width is 45 ± 5 nm, the length of the magnetic tunnel junction layer 90 is 45 ± 5 nm, and the width is 45 ± 5 nm, and the length of the top metal layer 80 is 45 ± 5 nm, and the width is 45 ± 5 nm.

[0064] In the embodiments of the present specification, the length of the top metal layer 80 and the magnetic tunnel junction layer 90 can be set to be the same, and the width of the top metal layer 80 and the magnetic tunnel junction layer 90 can be set to be the same; the length of the heavy metal layer 70 can be set to be greater than the length of the magnetic tunnel junction layer 90, and the widths of the heavy metal layer 70, the magnetic tunnel junction layer 90, and the top metal layer 80 can also be set to be the same; by way of example, the length of the heavy metal layer 70 can be set to 60 ± 5 nm, the width is 45 ± 5 nm, the length of the magnetic tunnel junction layer 90 is 45 ± 5 nm, and the width is 45 ± 5 nm, and the length of the top metal layer 80 is 45 ± 5 nm, and the width is 45 ± 5 nm.

[0065] In the embodiments of the present specification, the length of the heavy metal layer 70 can be set to be greater than the length of the magnetic tunnel junction layer 90, so as to facilitate leaving sufficient space at both ends in the length direction of the heavy metal layer 70 for setting the first access port 61 and the second access port 62, and to avoid the setting of the first access port 61 and the second access port 62 from affecting other layer structures located on the heavy metal layer 70.

[0066] In some exemplary embodiments, the magnetic tunnel junction layer 90 includes a stacked free layer 10, an oxide layer 20, and a fixed layer 30, and the free layer 10 is located on the heavy metal layer 70.

[0067] In the embodiments of this specification, a very thin insulating layer (oxide layer 20) is sandwiched between two ferromagnetic thin flakes to form a magnetic tunnel junction layer 90. In ferromagnetic materials, due to the quantum mechanical exchange interaction, the 3d orbital local electron energy band of ferromagnetic metals splits, causing the electrons with spin up and spin down near the Fermi surface to have different energy state densities. In magnetic tunnel junctions (MTJs), the generation mechanism of the TMR effect is the spin-dependent tunneling effect. The general structure of MTJs is a sandwich structure of ferromagnetic layer / non-magnetic insulating layer / ferromagnetic layer (FM / I / FM). When magnetized to saturation, the magnetization directions of the two ferromagnetic layers are parallel to each other. Usually, the coercive forces of the two ferromagnetic layers are different. Therefore, when magnetized in the reverse direction, the magnetization vector of the ferromagnetic layer with a smaller coercive force flips first, making the magnetization directions of the two ferromagnetic layers become anti-parallel. The tunneling probability of electrons tunneling from one magnetic layer to another is related to the magnetization directions of the two magnetic layers. If the magnetization directions of the two layers are parallel, in one magnetic layer, the electrons in the majority spin sub-band will enter the empty states of the majority spin sub-band in the other magnetic layer, and the electrons in the minority spin sub-band will also enter the empty states of the minority spin sub-band in the other magnetic layer, resulting in a relatively large total tunneling current. If the magnetization directions of the two magnetic layers are anti-parallel, the situation is just the opposite, that is, in one magnetic layer, the electrons in the majority spin sub-band will enter the empty states of the minority spin sub-band in the other magnetic layer, and the electrons in the minority spin sub-band will also enter the empty states of the majority spin sub-band in the other magnetic layer. The tunneling current in this state is relatively small. Therefore, the tunneling conductance changes with the change of the magnetization directions of the two ferromagnetic layers, and the conductance when the magnetization vectors are parallel is higher than that when they are anti-parallel.

[0068] In the embodiments of this specification, the top metal layer 80 is located on the fixed layer 30. The top metal layer 80 is used to generate a spin current, and under the action of an external voltage, it tunnels through the oxide layer 20 and enters the free layer 10 to flip the spin (magnetization) direction in the free layer 10.

[0069] In the embodiments of this specification, the magnetic tunnel junction layer 90 includes a stacked free layer 10, oxide layer 20, and fixed layer 30. The free layer 10 is located on the heavy metal layer 70. By setting the heavy metal layer 70 below the free layer 10, a current can be input into the heavy metal layer 70 to quickly adjust the initial spin angle of the free layer 10 so that the initial spin angle meets the preset conditions, thus facilitating the subsequent rapid flipping of the spin direction in the free layer 10.

[0070] In the embodiments of this specification, the thickness of the free layer 10 is less than or equal to the thickness of the fixed layer 30.

[0071] In the embodiments of this specification, the thickness of the free layer 10 can be set to be less than or equal to the thickness of the fixed layer 30. Exemplarily, the thickness of the free layer 10 is 1 - 2 nm, the thickness of the oxide layer 20 is 1 - 2 nm, and the thickness of the fixed layer 30 is 1 - 3 nm. Among them, the thicknesses of the free layer 10 and the oxide layer 20 can be the same or different. In an exemplary embodiment, the thicknesses of both the free layer 10 and the fixed layer 30 are greater than the thickness of the oxide layer 20.

[0072] In the embodiments of this specification, the thickness of the free layer 10 can be set to be less than or equal to the thickness of the fixed layer 30, and the thickness of the free layer 10 is set to be 1 - 2 nm, the thickness of the oxide layer 20 is 1 - 2 nm, and the thickness of the fixed layer 30 is 1 - 3 nm, so as to ensure the rapid and accurate reversal of the spin direction in the free layer 10.

[0073] In some embodiments, the material of the oxide layer 20 may include one or more of magnesium oxide compounds, silicon oxide compounds, silicon nitride compounds, aluminum oxide compounds, magnesium aluminum oxide compounds, titanium oxide layers, tantalum oxide compounds, calcium oxide compounds, and iron oxide compounds.

[0074] In the embodiments of this specification, the material of the oxide layer 20 includes at least one of magnesium oxide and aluminum oxide, and the material of the free layer 10 includes at least one of cobalt iron boron compounds, cobalt, iron chromium tellurium compounds, cobalt platinum alloys, cobalt palladium alloys, nickel platinum alloys, nickel palladium alloys, chromium telluride, iron palladium alloys, and cobalt palladium compounds; the material of the fixed layer 30 includes at least one of cobalt iron boron compounds, cobalt, iron chromium tellurium compounds, cobalt platinum alloys, cobalt palladium alloys, nickel platinum alloys, nickel palladium alloys, chromium telluride, iron palladium alloys, and cobalt palladium compounds.

[0075] In the embodiments of this specification, the selection ranges of the materials of the free layer 10 and the fixed layer 30 can be the same. The materials of the two structural layers are both selected from at least one of cobalt iron boron compounds, cobalt, iron chromium tellurium compounds, cobalt platinum alloys, cobalt palladium alloys, nickel platinum alloys, nickel palladium alloys, chromium telluride, iron palladium alloys, and cobalt palladium compounds; the material of the oxide layer 20 may include at least one of magnesium oxide and aluminum oxide. The material can be a single one or an alloy of several. Those skilled in the art can select appropriate materials according to the actual situation.

[0076] In the embodiments of this specification, the material sources corresponding to the free layer 10, the fixed layer 30, and the oxide layer 20 can be set, so as to ensure that the spin direction of the fixed layer 30 is a fixed direction and the spin direction of the free layer 10 can be adjusted.

[0077] In some embodiments, since the oxide layer 20 can reduce the influence of thermal diffusion of the heavy metal layer 70 on the free layer 10 when the heavy metal layer 70 is energized and reduce the interaction between the heavy metal layer 70 and the free layer 10, the thickness of the oxide layer 20 can be related to the degree of influence of thermal diffusion of the heavy metal layer 70 on the free layer 10 when the heavy metal layer 70 is energized. In addition, the thickness of the oxide layer 20 can also be related to the thickness loss caused by planarization treatment such as, but not limited to, chemical mechanical planarization process on the surface of the oxide layer 20 before the subsequent preparation of the magnetic tunnel junction layer 90.

[0078] In the embodiments of the present specification, the material of the heavy metal layer 70 includes at least one of platinum, palladium, tungsten, thallium, and alloy materials; the alloy material is composed of at least two of platinum, palladium, tungsten, and thallium.

[0079] In the embodiments of the present specification, it can be set that the material of the heavy metal layer 70 includes at least one of platinum, palladium, tungsten, thallium, and alloy materials; the alloy material is composed of at least two of platinum, palladium, tungsten, and thallium, that is, it can be a single one or an alloy of several. Those skilled in the art can select appropriate materials to form the heavy metal layer 70 according to the actual situation; thereby ensuring that after a first current is passed into the heavy metal layer 70, the initial spin angle of the free layer 10 can be quickly adjusted.

[0080] In the embodiments of the present specification, a storage unit is provided, including: a substrate; a heavy metal layer, a magnetic tunnel junction layer, and a top metal layer sequentially located on the substrate; the heavy metal layer is provided with a first access port and a second access port on both sides along a first preset direction, and the top metal layer is provided with a third access port along a second preset direction; the first preset direction is a direction parallel to the contact surface between the heavy metal layer and the substrate, and the first preset direction is perpendicular to the second preset direction; the magnetic tunnel junction layer includes a free layer; wherein, the first access port and the second access port are used to input a first current into the heavy metal layer, the third access port is used to input a second current into the top metal layer, and the first current and the second current are used to flip the spin direction of the free layer. The present invention facilitates controlling the direction of the first current input into the heavy metal layer by providing a heavy metal layer and arranging two access ports at both ends of the heavy metal layer, so as to finely adjust the spin direction in the free layer and deflect a preset angle. Then, a second current is input through the third access port in the top metal layer to completely flip the spin direction in the free layer. Since the free layer has deviated from the current spin direction and shifted a preset angle in the target direction, the input voltage corresponding to the second current is reduced, the success rate and the flipping speed of the free layer flipping are improved, and thus the accuracy and the writing speed of writing data in the storage unit are improved.

[0081] As Figure 8 shown,Figure 8 It is a flowchart of a method for forming a storage unit provided by an embodiment of the present invention. This embodiment provides a method for forming a storage unit, and the method includes:

[0082] S801: Provide a substrate;

[0083] S802: Form a heavy metal material layer on the substrate;

[0084] S803: Form a magnetic tunnel junction material layer on the heavy metal material layer;

[0085] S804: Form a top metal material layer on the magnetic tunnel junction material layer;

[0086] S805: Etch the top metal material layer, the magnetic tunnel junction material layer, and the heavy metal material layer in sequence to form a top metal layer, a magnetic tunnel junction layer, and a heavy metal layer; the magnetic tunnel junction layer includes a free layer; on both sides of the heavy metal layer along a first preset direction, a first access port and a second access port are respectively provided, and a third access port is provided on the top metal layer along a second preset direction; the first preset direction is a direction parallel to the contact surface between the heavy metal layer and the substrate, and the first preset direction is perpendicular to the second preset direction;

[0087] Wherein, the first access port and the second access port are used to input a first current into the heavy metal layer, and the third access port is used to input a second current into the top metal layer, and the first current and the second current are used to flip the spin direction of the free layer.

[0088] In the embodiment of this specification, the structure of the substrate is the same as the substrate structure in the above structural embodiment, and will not be elaborated here. After etching to form the heavy metal layer, a first access port and a second access port can be respectively formed at both ends of the heavy metal layer, and a third access port is set in a direction perpendicular to the top metal layer. Among them, the third access port can be set at the middle position of the top metal layer or at the edge position of the top metal layer.

[0089] In the embodiment of this specification, the step of etching the top metal material layer, the magnetic tunnel junction material layer, and the heavy metal material layer in sequence to form a top metal layer, a magnetic tunnel junction layer, and a heavy metal layer includes:

[0090] Etch the top metal material layer to form the top metal layer;

[0091] Etch the magnetic tunnel junction material layer to form the magnetic tunnel junction layer;

[0092] Etch the heavy metal material layer to form the heavy metal layer.

[0093] In the embodiments of the present specification, during the etching process of the structural layer, a dry etching process or a wet etching process may be employed to etch the top metal material layer to form the top metal layer, and to etch the magnetic tunnel junction material layer to form the magnetic tunnel junction layer; and to etch the heavy metal material layer to form the heavy metal layer.

[0094] In the embodiments of the present specification, forming the magnetic tunnel junction material layer on the heavy metal material layer includes:

[0095] Forming a free material layer on the heavy metal material layer;

[0096] Forming an oxidation material layer on the free material layer;

[0097] Forming a fixed material layer on the oxidation material layer; the free material layer, the oxidation material layer, and the fixed material layer constitute the magnetic tunnel junction material layer.

[0098] In the embodiments of the present specification, the magnetic tunnel junction material layer may be composed of a free material layer, an oxidation material layer, and a fixed material layer; before etching, the magnetic tunnel junction material layer may be first formed on the heavy metal material layer. Exemplarily, a free material layer is formed on the heavy metal material layer; an oxidation material layer is formed on the free material layer; and a fixed material layer is formed on the oxidation material layer; multiple material layers are formed from bottom to top first, and then each material layer is etched from top to bottom in sequence to form the structural layer.

[0099] In the embodiments of the present specification, the magnetic tunnel junction layer includes a stacked free layer, oxidation layer, and fixed layer. Etching the magnetic tunnel junction material layer to form the magnetic tunnel junction layer includes:

[0100] Etching the fixed material layer until the surface of the oxidation material layer is exposed to form the fixed layer;

[0101] Etching the oxidation material layer until the surface of the free material layer is exposed to form the oxidation layer;

[0102] Etching the free material layer until the surface of the substrate is exposed to form the free layer.

[0103] Exemplarily, the formation process of the magnetic tunnel junction material layer includes but is not limited to: chemical vapor deposition (CVD), physical vapor deposition (PVD), or atomic layer deposition (ALD) process.

[0104] In the embodiments of the present specification, the thickness of the heavy metal layer is 5 - 100 nm, the thickness of the magnetic tunnel junction layer is 3 - 7 nm, and the thickness of the top metal layer is 20 - 100 nm.

[0105] In the embodiments of this specification, the length of the heavy metal layer is 60 ± 5 nm, the width is 45 ± 5 nm, the length of the magnetic tunnel junction layer is 45 ± 5 nm, and the width is 45 ± 5 nm, and the length of the top metal layer is 45 ± 5 nm and the width is 45 ± 5 nm.

[0106] In the embodiments of this specification, the thickness of the free layer is 1 - 2 nm, the thickness of the oxide layer is 1 - 2 nm, and the thickness of the fixed layer is 1 - 3 nm.

[0107] In the embodiments of this specification, the material of the oxide layer includes at least one of magnesium oxide and aluminum oxide, and the material of the free layer includes at least one of cobalt iron boron compound, cobalt, iron chromium tellurium compound, cobalt platinum alloy, cobalt palladium alloy, nickel platinum alloy, nickel palladium alloy, chromium telluride, iron palladium alloy, and cobalt palladium compound; the material of the fixed layer includes at least one of cobalt iron boron compound, cobalt, iron chromium tellurium compound, cobalt platinum alloy, cobalt palladium alloy, nickel platinum alloy, nickel palladium alloy, chromium telluride, iron palladium alloy, and cobalt palladium compound.

[0108] In the embodiments of this specification, the material of the heavy metal layer includes at least one of platinum, palladium, tungsten, thallium, and alloy materials; the alloy material is composed of at least two of platinum, palladium, tungsten, and thallium.

[0109] The materials of the respective structural layers in this embodiment are the same as those of the corresponding structural layers in the above structural embodiment.

[0110] This embodiment provides a substrate; a heavy metal material layer is formed on the substrate; a magnetic tunnel junction material layer is formed on the heavy metal material layer; a top metal material layer is formed on the magnetic tunnel junction material layer; the top metal material layer, the magnetic tunnel junction material layer, and the heavy metal material layer are etched in sequence to form a top metal layer, a magnetic tunnel junction layer, and a heavy metal layer; the magnetic tunnel junction layer includes a free layer; a first access port and a second access port are respectively arranged on two sides of the heavy metal layer in a first preset direction, and a third access port is arranged on the top metal layer in a second preset direction; the first preset direction is a direction parallel to the contact surface between the heavy metal layer and the substrate, and the first preset direction is perpendicular to the second preset direction; wherein, the first access port and the second access port are used to input a first current into the heavy metal layer, and the third access port is used to input a second current into the top metal layer, and the first current and the second current are used to flip the spin direction of the free layer. By arranging a heavy metal layer under the magnetic tunnel junction material layer and arranging two access ports at both ends of the heavy metal layer, it is convenient to control the direction of the first current input into the heavy metal layer, so as to finely adjust the spin direction in the free layer and deflect a preset angle, and then input a second current through the third access port in the top metal layer to completely flip the spin direction in the free layer. Since the free layer has deviated from the current spin direction and shifted a preset angle in the target direction, the input voltage corresponding to the second current is reduced, the success rate and the flipping speed of the free layer flipping are improved, and thus the accuracy and the writing speed of writing data into the storage unit are improved.

[0111] As Figure 9 shown, Figure 9 is a flowchart of a data writing method for a storage unit according to this embodiment. This embodiment provides a data writing method for a storage unit. The data writing method includes:

[0112] S901: Obtain the current resistance state and the data to be written of the storage unit;

[0113] S902: Determine the target resistance state of the storage unit according to the data type corresponding to the data to be written;

[0114] S903: According to the target resistance state and the current resistance state, input the first current in the target direction into the heavy metal layer through the first access port and the second access port; the first current is used to deflect the spin direction of the free layer by a preset angle;

[0115] S904: Input a second current into the top metal layer through the third access port to flip the spin direction of the free layer and write the data to be written.

[0116] In the embodiments of this specification, the structure of the storage unit has been described in the above structural embodiments, and it includes a free layer, a fixed layer, and a tunneling oxide. STT-MTJ uses the magnetic moment directions of the free layer and the fixed layer to store information. In the parallel state, the resistance is low resistance, and the written data is 0; in the anti-parallel state, the resistance is high resistance, and the written data is 1. The memory reading circuit determines the information of the memory by judging the magnitude of the output current by applying the same voltage.

[0117] In the embodiments of this specification, when a data writing request is received, the current resistance state of the storage unit and the data to be written can be obtained. Among them, the current resistance state can be a high-resistance state or a low-resistance state, and the data to be written can be 0 or 1; the target resistance state of the storage unit can be determined according to the data type corresponding to the data to be written; when the data to be written is 0, the target resistance state is a low-resistance state; when the data to be written is 1, the target resistance state is a high-resistance state; after determining the current resistance state and the target resistance state, it can be compared whether the current resistance state and the target resistance state are consistent. If the two are consistent, the data to be written can be written without flipping the spin direction of the free layer; if the target resistance state does not match the current resistance state, the target direction of the input current in the heavy metal layer is further determined according to the target resistance state; then the first current in the target direction is input into the heavy metal layer through the first access port and the second access port; the first current is used to deflect the spin direction of the free layer by a preset angle; then a second current is input into the top metal layer through the third access port to flip the spin direction of the free layer and write the data to be written; on the one hand, the voltage corresponding to the second current can be reduced to reduce the storage energy consumption, and on the other hand, the spin direction flipping speed and flipping accuracy of the free layer can be improved, and the data writing accuracy and writing rate can be improved.

[0118] In the embodiments of this specification, the input duration of the first current is the first duration, and the input duration of the second current is the second duration; the first duration is less than the second duration.

[0119] Optionally, the ratio of the pulse widths of the first current and the second current can be 1:10 - 30.

[0120] Optionally, the first duration is 1 - 10 picoseconds, and the second duration is 100 - 900 nanoseconds. Among them, 1 picosecond is equal to one trillionth of a second, and 1000 picoseconds = 1 nanosecond.

[0121] In the embodiments of this specification, if it is necessary to switch the spin direction in the free layer and change the resistance of the MTJ, only a first current with a pulse width of several hundred picoseconds needs to be input into the heavy metal to generate a spin-orbit torque, which can slightly change the spin direction of the nearby free layer. Then, a second current with a pulse width in the nanosecond (ns) range is input into the top metal layer, thereby generating a torque that can completely change the spin of the free layer.

[0122] Optionally, the step of inputting the first current into the heavy metal layer through the first access port and the second access port according to the target resistance state and the current resistance state includes:

[0123] Determine whether the target resistance state matches the current resistance state;

[0124] When the target resistance state does not match the current resistance state, determine the target direction of the current input into the heavy metal layer;

[0125] Input the first current corresponding to the target direction into the heavy metal layer through the first access port and the second access port.

[0126] In an exemplary embodiment, when the target resistance state matches the current resistance state, the spin direction of the free layer is not flipped, and the data to be written can be written.

[0127] Optionally, the step of determining the target direction of the current input into the heavy metal layer when the target resistance state does not match the current resistance state includes:

[0128] When the target resistance state does not match the current resistance state, obtain the current direction of the current currently input into the heavy metal layer;

[0129] Determine the opposite direction of the current direction as the target direction of the current input into the heavy metal layer.

[0130] Optionally, the step of inputting the second current into the top metal layer through the third access port to flip the spin direction of the free layer and write the data to be written includes:

[0131] If the target resistance state is a high-resistance state, input the second current into the top metal layer through the third access port to flip the spin direction of the free layer, so that the flipping direction of the free layer is opposite to the spin direction of the fixed layer, and write the data to be written;

[0132] If the target resistance state is a low-resistance state, a second current is input into the top metal layer through the third access port to flip the spin direction of the free layer, so that the flipping direction of the free layer is the same as the spin direction of the fixed layer, and the data to be written is written.

[0133] In the embodiments of the present specification, if the target resistance state is a high-resistance state, first, a first current in a first target direction is input into the heavy metal layer through the first access port and the second access port; so that the spin direction of the free layer deflects by a preset angle; then, a second current is input into the top metal layer through the third access port to flip the spin direction of the free layer, so that the flipping direction of the free layer is opposite to the spin direction of the fixed layer, and the data to be written is written; if the target resistance state is a low-resistance state, first, a first current in a first target direction is input into the heavy metal layer through the first access port and the second access port; so that the spin direction of the free layer deflects by a preset angle; then, a second current is input into the top metal layer through the third access port to flip the spin direction of the free layer, so that the flipping direction of the free layer is the same as the spin direction of the fixed layer, and the data to be written is written; wherein, the first target direction is opposite to the second target direction.

[0134] In an exemplary embodiment, as Figure 10 shown, Figure 10 is a schematic diagram of a data writing method for a storage unit Figure One , the spin directions of the electrons in the fixed layer and the free layer in the storage unit are the same. At this time, the written data is 0; the current resistance state is a low-resistance state; the data to be written is 1, and the target resistance state is a high-resistance state. At this time, it is necessary to pass a first current into the heavy metal layer along the T1-T2 direction, and then pass a second current into the top metal layer along a direction perpendicular to the first current direction and towards the top metal layer, so as to realize the flipping of the spin direction in the free layer.

[0135] In an exemplary embodiment, as Figure 11 shown, Figure 11 is a schematic diagram of a data writing method for a storage unit Figure Two , the spin directions of the electrons in the fixed layer and the free layer in the storage unit are opposite. At this time, the written data is 1; the current resistance state is a high-resistance state; the data to be written is 0, and the target resistance state is a low-resistance state. At this time, it is necessary to pass a first current into the heavy metal layer along the T2-T1 direction, and then pass a second current into the top metal layer along a direction perpendicular to the first current direction and away from the top metal layer, so as to realize the flipping of the spin direction in the free layer.

[0136] In an exemplary embodiment, as Figures 12 - 14 shown, Figure 12It is a current-time curve graph corresponding to a first current introduced into a heavy metal layer, and the introduction time of the first current is less than 5 ns; Figure 13 It is a current-time curve graph corresponding to a second current introduced into a top metal layer, and the introduction time of the second current is less than 20 ns; Figure 14 It is a time-resistance curve graph during the introduction of the first current and the second current, Figure 14 The first current in Figure 12 corresponds to Figure 14 The second current in Figure 13 corresponds to Figure 14 It can be seen that the storage unit realizes the switching from the low-resistance state to the high-resistance state within 2 ns, realizes the rapid switching of the resistance state, and thus realizes the rapid writing of data.

[0137] In an exemplary embodiment, Figure 15 It is a writing data time curve graph corresponding to an initial spin angle of 0.15 rad; after introducing the first current, the initial spin angle of the free layer is 0.15 rad, and then the second current is introduced to realize the flipping of the spin direction of the free layer and write data; Figure 16 It is a writing data time curve graph corresponding to an initial spin angle of 0.06 rad; after introducing the first current, the initial spin angle of the free layer is 0.06 rad, and then the second current is introduced to realize the flipping of the spin direction of the free layer and write data; it can be seen that the storage unit of this embodiment can realize the rapid flipping of the spin direction of the free layer within 2 ns under both spin angles; compared with Figure 6 and Figure 16 It can be seen that the storage unit of the prior art still cannot realize the flipping of the spin direction of the free layer at an angle of 0.06 rad after 30 ns; while the storage unit of this embodiment can realize the rapid flipping of the spin direction of the free layer within 2 ns; obviously, the storage unit of this embodiment can improve the data writing rate and the data writing success rate.

[0138] The present invention also provides a memory, and the memory includes the storage unit as described in any of the above embodiments. The memory may include, but is not limited to, a Spin Transfer Torque Magnetic Random Access Memory (STT-MRAM).

[0139] Other embodiments of the present application will be readily apparent to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. The present application is intended to cover any variations, uses, or adaptations of the present application, which follow the general principles of the present application and include well-known knowledge or conventional technical means in the technical field not disclosed in the present application. The specification and examples are only regarded as exemplary, and the true scope and spirit of the present application are pointed out by the claims.

[0140] It should be understood that the present application is not limited to the exact structures described above and shown in the drawings, and various modifications and changes can be made without departing from its scope. The scope of the present application is only limited by the appended claims.

Claims

1. A storage unit, characterized in that, Comprising: A substrate; A heavy metal layer, a magnetic tunnel junction layer, and a top metal layer successively located on the substrate; the two sides of the heavy metal layer in the first preset direction are respectively provided with a first access port and a second access port, and the top metal layer is provided with a third access port in the second preset direction; the first preset direction is a direction parallel to the contact surface of the heavy metal layer and the substrate, and the first preset direction is perpendicular to the second preset direction; the magnetic tunnel junction layer includes a free layer. Wherein, the first access port and the second access port are used to input a first current into the heavy metal layer, and the third access port is used to input a second current into the top metal layer, and the first current and the second current are used to flip the spin direction of the free layer.

2. The memory cell according to claim 1, wherein The thickness of the heavy metal layer is 5 - 100 nm, the thickness of the magnetic tunnel junction layer is 3 - 7 nm, and the thickness of the top metal layer is 20 - 100 nm.

3. The memory cell according to claim 2, wherein, The length of the heavy metal layer is 60 ± 5 nm, the width is 45 ± 5 nm, the length of the magnetic tunnel junction layer is 45 ± 5 nm, the width is 45 ± 5 nm, and the length of the top metal layer is 45 ± 5 nm, the width is 45 ± 5 nm.

4. The memory cell according to claim 1, wherein, The magnetic tunnel junction layer includes a stacked free layer, an oxide layer, and a fixed layer, and the free layer is located on the heavy metal layer.

5. The memory cell according to claim 4, wherein The thickness of the free layer is less than or equal to the thickness of the fixed layer.

6. The memory cell according to claim 5, wherein, The thickness of the free layer is 1 - 2 nm, the thickness of the oxide layer is 1 - 2 nm, and the thickness of the fixed layer is 1 - 3 nm.

7. The storage unit according to claim 4, characterized in that, The material of the oxide layer includes at least one of magnesium oxide and aluminum oxide, and the material of the free layer includes at least one of cobalt iron boron compound, cobalt, iron chromium tellurium compound, cobalt platinum alloy, cobalt palladium alloy, nickel platinum alloy, nickel palladium alloy, chromium telluride, iron palladium alloy, cobalt palladium compound; the material of the fixed layer includes at least one of cobalt iron boron compound, cobalt, iron chromium tellurium compound, cobalt platinum alloy, cobalt palladium alloy, nickel platinum alloy, nickel palladium alloy, chromium telluride, iron palladium alloy, cobalt palladium compound.

8. The memory cell according to claim 1, wherein The material of the heavy metal layer includes at least one of platinum, palladium, tungsten, thallium, and alloy materials; the alloy materials are composed of at least two of platinum, palladium, tungsten, and thallium.

9. A method for forming a memory cell, characterized in that, The method includes: Providing a substrate; Forming a heavy metal material layer on the substrate; Forming a magnetic tunnel junction material layer on the heavy metal material layer; Forming a top metal material layer on the magnetic tunnel junction material layer; Etching the top metal material layer, the magnetic tunnel junction material layer, and the heavy metal material layer in sequence to form a top metal layer, a magnetic tunnel junction layer, and a heavy metal layer; the magnetic tunnel junction layer includes a free layer; the two sides of the heavy metal layer in the first preset direction are respectively provided with a first access port and a second access port, and the top metal layer is provided with a third access port in the second preset direction; the first preset direction is a direction parallel to the contact surface of the heavy metal layer and the substrate, and the first preset direction is perpendicular to the second preset direction. Wherein, the first access port and the second access port are used to input a first current into the heavy metal layer, and the third access port is used to input a second current into the top metal layer. The first current and the second current are used to flip the spin direction of the free layer.

10. The method according to claim 9, characterized in that The sequentially etching the top metal material layer, the magnetic tunnel junction material layer, and the heavy metal material layer to form a top metal layer, a magnetic tunnel junction layer, and a heavy metal layer includes: Etching the top metal material layer to form the top metal layer; Etching the magnetic tunnel junction material layer to form the magnetic tunnel junction layer; Etching the heavy metal material layer to form the heavy metal layer.

11. The method according to claim 10, wherein The forming the magnetic tunnel junction material layer on the heavy metal material layer includes: Forming a free material layer on the heavy metal material layer; Forming an oxide material layer on the free material layer; Forming a fixed material layer on the oxide material layer; the free material layer, the oxide material layer, and the fixed material layer constitute the magnetic tunnel junction material layer.

12. The method according to claim 11, wherein The magnetic tunnel junction layer includes a stacked free layer, an oxide layer, and a fixed layer. The etching the magnetic tunnel junction material layer to form the magnetic tunnel junction layer includes: Etching the fixed material layer until the surface of the oxide material layer is exposed to form the fixed layer; Etching the oxide material layer until the surface of the free material layer is exposed to form the oxide layer; Etching the free material layer until the surface of the substrate is exposed to form the free layer.

13. A method for writing data to a storage unit according to any one of claims 1 to 8, characterized in that, The data writing method includes: Obtaining the current resistance state of the storage unit and the data to be written; Determining the target resistance state of the storage unit according to the data type corresponding to the data to be written; According to the target resistance state and the current resistance state, inputting a first current into the heavy metal layer through the first access port and the second access port; the first current is used to deflect the spin direction of the free layer by a preset angle; Inputting a second current into the top metal layer through the third access port to flip the spin direction of the free layer and write the data to be written.

14. The data writing method according to claim 13, wherein The input duration of the first current is a first duration, and the input duration of the second current is a second duration; the first duration is less than the second duration.

15. The data writing method according to claim 14, wherein The first duration is 1 - 10 picoseconds, and the second duration is 100 - 900 nanoseconds.

16. The data writing method according to claim 13, wherein The according to the target resistance state and the current resistance state, inputting a first current into the heavy metal layer through the first access port and the second access port includes: Judging whether the target resistance state matches the current resistance state; When the target resistance state does not match the current resistance state, determining the target direction of the current input into the heavy metal layer; Inputting a first current corresponding to the target direction into the heavy metal layer through the first access port and the second access port.

17. The data writing method according to claim 16, wherein The when the target resistance state does not match the current resistance state, determining the target direction of the current input into the heavy metal layer includes: When the target resistance state does not match the current resistance state, obtain the current direction of the current input to the heavy metal layer at present; Determine the reverse direction of the current direction as the target direction of the current input to the heavy metal layer.

18. The data writing method according to claim 13, wherein The step of inputting a second current into the top metal layer through the third access port to flip the spin direction of the free layer and write the data to be written includes: If the target resistance state is a high-resistance state, input a second current into the top metal layer through the third access port to flip the spin direction of the free layer, so that the flipping direction of the free layer is opposite to the spin direction of the fixed layer, and write the data to be written; If the target resistance state is a low-resistance state, input a second current into the top metal layer through the third access port to flip the spin direction of the free layer, so that the flipping direction of the free layer is the same as the spin direction of the fixed layer, and write the data to be written.

19. A memory, characterized in that, The memory includes the storage unit as described in any one of claims 1-8.

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