A memory and electronic device

Abstract

Embodiments of the present application provide a memory and an electronic device, and relate to the technical field of memories, and can improve the flipping speed of a free layer. The memory comprises a plurality of memory cells and a bit line arranged in an array in a storage area of the memory. The memory cell comprises a transistor and a magnetic tunnel junction (MTJ) element connected to the transistor. The MTJ element is arranged on a current transmission path between a source or a drain of the transistor and the bit line. The MTJ element comprises a pinned layer, a reference layer, a tunneling layer and a free layer arranged in sequence. The magnetization direction of the pinned layer is parallel to the stacking direction of each layer in the MTJ. The memory further comprises a first magnetic structure arranged on the current transmission path. The direction of the magnetic field generated by the first magnetic structure is not parallel to the magnetization direction of the free layer.

Description

Technical Field

[0001] This application relates to the field of memory technology, and more particularly to a memory and electronic device. Background Technology

[0002] Magnetic random access memory (MRAM) is a novel type of non-volatile memory. Among them, spin transfer torque magnetic random access memory (STT MRAM) has attracted widespread attention due to its advantages such as high speed, low power consumption, and good CMOS (complementary metal-oxide-semiconductor) compatibility.

[0003] The read and write functions of a spin-shift magnetic random access memory (SRAM) are implemented by its memory cells. The main structure of a memory cell consists of a magnetic tunneling junction (MTJ) element and a transistor. The MTJ structure is primarily composed of a free layer for storing information, a tunneling layer, a reference layer with a fixed magnetization direction, and pinned layers stacked sequentially. The magnetization direction of the reference layer is pinned to a fixed direction by the pinned layers, while the magnetization direction of the free layer can change. When current flows through the MTJ from different directions (current from the fixed layer to the free layer or vice versa), the magnetization direction of the free layer changes accordingly. When the magnetization direction of the free layer is parallel to that of the reference layer (i.e., the free layer and the reference layer have the same magnetization direction), the memory cell exhibits low resistance and can store a value of "0". When the magnetization direction of the free layer is antiparallel to that of the reference layer (i.e., the free layer and the reference layer have opposite magnetization directions), the memory cell exhibits high resistance and can store a value of "1". Reading from a magnetic random access memory (MRMemory) involves detecting the resistance of the memory cell. A constant small current flows through the bit line (MTJ), creating a potential difference across the MTJ. The resistance of the MTJ can be determined based on the magnitude of this potential difference, which in turn determines whether the information stored in the MRMemory is "0" or "1".

[0004] Currently, the write efficiency of storage cells is affected because the free layer flips slowly when writing data. Summary of the Invention

[0005] This application provides a memory and electronic device that can improve the flipping speed of the free layer.

[0006] To achieve the above objectives, this application adopts the following technical solution:

[0007] Firstly, a memory is provided. The memory includes a plurality of memory cells and bit lines arranged in an array within a memory region. Each memory cell includes a transistor and a magnetic tunnel junction (MTJ) element connected to the transistor. The MTJ element is disposed on a current transport path between the source or drain of the transistor and the bit line. The MTJ element includes a pinned layer, a reference layer, a tunneling layer, and a free layer stacked sequentially. The magnetization direction of the pinned layer is parallel to the stacking direction of the layers in the MTJ. The memory also includes a first magnetic structure disposed on the current transport path. The direction of the magnetic field generated by the first magnetic structure in the free layer is not parallel to the magnetization direction of the free layer. Because the direction of the magnetic field generated by the first magnetic structure in the free layer is not parallel to the magnetization direction of the free layer, the magnetic field generated by the first magnetic structure in the free layer can apply a magnetic force to the free layer, which is beneficial for the flipping of the free layer. This reduces the current required for the free layer to flip, reduces the incubation time of the STT (Sinking Tolerance Time), increases the flipping speed of the free layer, shortens the write time, and improves the write efficiency.

[0008] In one possible implementation, the direction of the magnetic field generated by the first magnetic structure in the free layer is perpendicular to the magnetization direction of the free layer. This results in a stronger magnetic field generated by the first magnetic structure in the free layer, which is more conducive to the flipping of the free layer, thus further reducing the incubation time of STT and more effectively increasing the flipping speed of the free layer.

[0009] In one possible implementation, the memory further includes a connection layer disposed between the first magnetic structure and the MTJ element, the first magnetic structure being electrically connected to the MTJ element via the connection layer; wherein the projection of the MTJ element onto the connection layer and the projection of the first magnetic structure onto the connection layer do not overlap in at least a portion of their areas. The direction of the magnetic field generated by the first magnetic structure in the free layer can be adjusted by adjusting the magnetization direction of the first magnetic structure and the relative position of the MTJ element and the first magnetic structure in a direction perpendicular to the stacking direction of the layers in the MTJ, so that the direction of the magnetic field generated by the first magnetic structure in the free layer is not parallel to the magnetization direction of the free layer.

[0010] In one possible implementation, the first magnetic structure is connected between the MTJ element and the source or drain of the transistor.

[0011] In one possible implementation, the first magnetic structure is connected between the MTJ element and the bit line.

[0012] In one possible implementation, the MTJ element further includes a first electrode and a second electrode; the first electrode is located on the side of the free layer away from the pinning layer, and the second electrode is located on the side of the pinning layer away from the free layer; the first electrode is electrically connected to a bit line, and the second electrode is electrically connected to the source or drain of the transistor; alternatively, the first electrode is electrically connected to the source or drain of the transistor, and the second electrode is electrically connected to the bit line. Here, the magnitude of the voltage applied to the first and second electrodes determines the direction of current flow in the MTJ element.

[0013] In one possible implementation, the material of the first magnetic structure includes one or more of elemental cobalt, elemental iron, elemental nickel, and alloys containing at least one of cobalt, iron, and nickel.

[0014] In one possible implementation, the pinning layer includes a first sub-pinning layer, a non-magnetic layer, and a second sub-pinning layer stacked sequentially; the magnetization direction of the first sub-pinning layer is opposite to the magnetization direction of the second sub-pinning layer. Since the pinning layer includes a first sub-pinning layer and a second sub-pinning layer, and the magnetization direction of the first sub-pinning layer is opposite to that of the second sub-pinning layer, the direction of the stray field generated by the first sub-pinning layer in the free layer is opposite to the direction of the stray field generated by the second sub-pinning layer in the free layer. Therefore, the stray fields generated by the first sub-pinning layer and the second sub-pinning layer in the free layer can cancel each other out, thereby reducing or eliminating the influence of the stray field generated by the pinning layer in the free layer on the free layer flipping, and thus reducing the current required for free layer flipping.

[0015] In one possible implementation, both the first sub-pinning layer and the second sub-pinning layer include ferromagnetic layers and heavy metal layers that are alternately stacked along the stacking direction of each layer in the MTJ.

[0016] In one possible implementation, the ferromagnetic layer is made of one or more of elemental cobalt, elemental iron, elemental nickel, and alloys containing at least one of cobalt, iron, and nickel; the heavy metal layer is made of one or more of elemental platinum, elemental tantalum, elemental copper, elemental iridium, elemental ruthenium, elemental tungsten, and alloys containing at least one of platinum, tantalum, copper, iridium, ruthenium, and tungsten.

[0017] In one possible implementation, the memory further includes a second magnetic structure disposed on the current transmission path and in contact with the MTJ element; the magnetization direction of the second magnetic structure forms an angle (90°, 180°) with the magnetization direction of the pinned layer; wherein, the first magnetic structure is connected between the MTJ element and the source or drain of the transistor, and the second magnetic structure is connected between the MTJ element and the bit line; or, the first magnetic structure is connected between the MTJ element and the bit line, and the second magnetic structure is connected between the MTJ element and the source or drain of the transistor. Since the magnetization direction of the second magnetic structure forms an angle (90°, 180°) with the magnetization direction of the pinned layer, the magnetic field generated by the second magnetic structure in the free layer can cancel the magnetic field generated by the pinned layer in the free layer, thereby reducing or eliminating the compensation field generated by the free layer. In this way, the current required for the free layer to flip is reduced, and the problem of MTJ flip asymmetry (i.e., the current required to change the magnetization direction of the free layer in opposite directions is different) can be solved.

[0018] In one possible implementation, the magnetization direction of the second magnetic structure is opposite to that of the pinned layer, and the magnetic field generated by the second magnetic structure in the free layer is the same magnitude as that generated by the pinned layer in the free layer. In this way, the magnetic field generated by the second magnetic structure in the free layer can cancel the magnetic field generated by the pinned layer in the free layer. Therefore, the magnetic field experienced by the free layer is zero or close to zero, and the compensation field generated by the magnetic field in the free layer is zero or close to zero. This further reduces the current required for the free layer to flip, and more effectively solves the problem of MTJ flipping asymmetry.

[0019] In one possible implementation, the magnetization direction of the second magnetic structure is opposite to that of the pinned layer, and the magnetic field generated by the second magnetic structure in the free layer is the same magnitude as the magnetic fields generated by the pinned layer and the reference layer in the free layer. In this way, the magnetic fields generated by the pinned layer and the reference layer in the free layer can be canceled out by the magnetic field generated by the second magnetic structure in the free layer, further reducing the current required for free layer flipping.

[0020] In one possible implementation, the pinning layer comprises alternating layers of ferromagnetic and heavy metal along the stacking direction of the layers in the MTJ. Since the pinning layer consists only of alternating layers of ferromagnetic and heavy metal along the stacking direction of the layers in the MTJ, its thickness is significantly reduced, simplifying the structure. This is beneficial for reducing the roughness of the interface between the tunneling layer and the free layer, reducing stress accumulation, and facilitating the miniaturization of the MTJ. Furthermore, the significantly reduced thickness of the pinning layer, i.e., the reduced thickness of the conductive material beneath the tunneling layer, lowers the probability of short circuits caused by backsplashing during etching, thus improving the engineering yield.

[0021] In one possible implementation, the pinning layer is made of a perpendicularly magnetically anisotropic material. Because the pinning layer is made of a perpendicularly magnetically anisotropic material, its magnetization direction can easily be magnetized parallel to the stacking direction of the layers in the MTJ. Therefore, the thickness of the pinning layer can be set to be smaller. This simplifies the structure, helps reduce the roughness of the interface between the tunneling layer and the free layer, reduces stress accumulation, and facilitates the miniaturization of the MTJ. Furthermore, the significantly reduced thickness of the pinning layer, i.e., the reduced thickness of the conductive material beneath the tunneling layer, lowers the probability of short circuits caused by sputtering during etching, thus improving the engineering yield.

[0022] In one possible implementation, the pinning layer is made of one or more of an iron-platinum alloy and a cobalt-platinum alloy. Here, both the iron-platinum alloy and the cobalt-platinum alloy are perpendicular magnetic anisotropy materials.

[0023] In one possible implementation, the reference layer and the free layer are made of a cobalt-iron-boron (CoFeB) alloy; the tunneling layer is made of magnesium oxide (MgO).

[0024] In one possible implementation, the gate of the transistor is connected to the word line control circuit via the word line WL, and the source or drain of the transistor is connected to the data line; the bit line BL is connected to the bit line control circuit.

[0025] Secondly, an electronic device is provided. This electronic device includes a circuit board and a memory electrically connected to the circuit board, the memory being the memory described above. This electronic device has the same technical effects as the foregoing embodiments, and will not be repeated here. Attached Figure Description

[0026] Figure 1a A schematic diagram of the structure of a storage system provided for an embodiment of this application;

[0027] Figure 1b A schematic diagram of the structure of a storage system provided for another embodiment of this application;

[0028] Figure 1c A schematic diagram of the structure of a storage system provided in another embodiment of this application;

[0029] Figure 2 A schematic diagram of a memory structure provided for an embodiment of this application;

[0030] Figure 3a A schematic diagram of the structure of an MTJ element provided for an embodiment of this application;

[0031] Figure 3b A schematic diagram of the structure of an MTJ element is provided for another embodiment of this application;

[0032] Figure 4aA schematic diagram of the structure of a memory provided for another embodiment of this application;

[0033] Figure 4b A schematic diagram of an MTJ element, a conductive structure, and a first magnetic structure provided for embodiments of this application;

[0034] Figure 5a A schematic diagram of the structure of a memory provided in another embodiment of this application;

[0035] Figure 5b A schematic diagram of an MTJ element, a conductive structure, and a first magnetic structure is provided for another embodiment of this application;

[0036] Figure 6a A schematic diagram of a memory structure provided for yet another embodiment of this application;

[0037] Figure 6b A schematic diagram of an MTJ element and a first magnetic structure provided for embodiments of this application;

[0038] Figure 7a A schematic diagram of the structure of a memory provided for another embodiment of this application;

[0039] Figure 7b A schematic diagram of an MTJ element, a conductive structure, and a first magnetic structure provided in another embodiment of this application;

[0040] Figure 8a A schematic diagram illustrating the direction of the magnetic field inside and outside a first or second magnetic structure, provided for embodiments of this application.

[0041] Figure 8b for Figure 8a The simulation result diagram of the plane marked by the black line B in the figure;

[0042] Figure 9 This is a schematic diagram of the MTJ component.

[0043] Figure 10 This is a structural diagram of the first sub-pinning layer, the second sub-pinning layer, or the pinning layer in an MTJ component;

[0044] Figure 11a A schematic diagram of the structure of a memory provided in another embodiment of this application;

[0045] Figure 11b A schematic diagram of an MTJ element, a first magnetic structure, and a second magnetic structure provided for embodiments of this application;

[0046] Figure 12aA schematic diagram of a memory structure provided for yet another embodiment of this application;

[0047] Figure 12b A schematic diagram of an MTJ element, a first magnetic structure, and a second magnetic structure is provided for another embodiment of this application;

[0048] Figure 13 for Figure 8a The simulation results are shown in the figure, where the positions are marked by the black lines A and B.

[0049] Figure label:

[0050] 10-Memory; 11-Memory cell; 12-MTJ element; 13-Substrate; 15-Conductive layer; 16-First magnetic structure; 17-Second magnetic structure; 18-Connection layer; 121-First electrode; 122-Second electrode; 141-Source; 142-Drain; 143-Active layer; 144-Gate; 151-First conductive portion; 152-Second conductive portion; 1231-Pinning layer; 1232-Reference layer; 1233-Tunneling layer; 1234-Free layer; 1235-Seed layer; 1236-Structure conversion layer; 1237-Capping layer. Detailed Implementation

[0051] The technical solutions of the embodiments of this application will be described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0052] Unless otherwise defined, all technical terms used herein have the same meaning as commonly known to one of ordinary skill in the art.

[0053] Hereinafter, the terms "first," "second," etc., are used for descriptive convenience only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. Furthermore, the term "electrical connection" can refer to a direct electrical connection or an indirect electrical connection via an intermediate medium.

[0054] It should be noted that, in this application, the terms "exemplary" or "for example" are used to indicate that something is being described as an example, illustration, or illustration. Any embodiment or design described as "exemplary" or "for example" in this application should not be construed as being more preferred or advantageous than other embodiments or design solutions. Specifically, the use of terms such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0055] The technical solutions provided in this application can be applied to various storage systems employing magnetic random access memory. For example, the technical solutions provided in this application can be applied to computers. As another example, the technical solutions provided in this application can be applied to storage systems that include memory, or include a processor and memory, wherein the processor can be a central processing unit (CPU), an artificial intelligence (AI) processor, a digital signal processor, or a neural network processor, etc.

[0056] Figure 1a This is a schematic diagram of a storage system provided in an embodiment of this application. The storage system may include a storage device, which may be a magnetic random access memory. Optionally, the storage system may also include a CPU, a cache, and a controller.

[0057] In one embodiment, such as Figure 1a As shown, the storage system includes an integrated CPU, cache, and storage device. In another embodiment, as... Figure 1b As shown, the storage system can be a standalone memory, comprising an integrated CPU, cache, controller, and storage device, the storage device being coupled to the cache and CPU via the controller. In another embodiment, as... Figure 1c As shown, the storage system includes a storage device, as well as an integrated CPU, cache, controller, and dynamic random access memory (DRAM). The storage device can be coupled to the DRAM as an external storage device. The DRAM is coupled to the cache and the CPU through the controller. Figure 1a , Figure 1b and Figure 1c The CPUs in the various storage systems shown can also be replaced with CPU cores. Figure 1a , Figure 1b and Figure 1c The storage device can be a magnetic random access memory.

[0058] This application provides a magnetic random access memory (hereinafter referred to as memory) that can be applied to the storage system described above. For example... Figure 2 As shown, the structure of the memory 10 includes a plurality of memory cells 11 arranged in an array within the memory region of the memory 10. Each memory cell 11 includes a transistor T and a magnetic tunnel junction (MTJ) element 12 connected to the transistor T.

[0059] The transistor T mentioned above can be a thin film transistor (TFT), or other types of transistors such as a MOS (metal oxide semiconductor) transistor. Transistor T includes a source, a drain, an active layer, a gate insulating layer, and a gate. The source and drain are both in contact with the active layer, and the gate insulating layer is disposed between the gate and the active layer.

[0060] like Figure 2 As shown, the structure of memory 10 also includes multiple parallel word lines (WL) and multiple parallel bit lines (BL), with the word lines WL and bit lines BL intersecting each other, for example, the word lines WL and bit lines BL are perpendicular to each other. In some embodiments, memory 10 also includes multiple parallel data lines, which may be parallel to the bit lines BL. The gate of transistor T is electrically connected to the word line WL, and the source or drain of transistor T is electrically connected to the data line. Here, the source of transistor T may be electrically connected to the data line, in which case the data line may also be called a source line (SL); alternatively, the drain of transistor T may be electrically connected to the data line. (See attached diagram.) Figure 2 The diagram is illustrated using the example of a source-to-source line connection of transistor T.

[0061] In some embodiments, the word line WL is also electrically connected to a word line control circuit, which provides a high-level signal or a low-level signal to the word line WL to turn the transistor T on or off. When transistor T is an N-type transistor, a high-level signal turns the transistor T on, and a low-level signal turns it off. When transistor T is a P-type transistor, a low-level signal turns the transistor T on, and a high-level signal turns it off.

[0062] In some embodiments, bit line BL is also electrically connected to a bit line control circuit, which provides signals to bit line BL.

[0063] In some embodiments, the data line is grounded.

[0064] The MTJ element 12 is disposed on the current transport path between the source or drain of transistor T and bit line BL.

[0065] like Figure 3aAs shown, the MTJ element 12 includes a first electrode 121, a second electrode 122, and an MTJ located between the first electrode 121 and the second electrode 122. The MTJ includes a pinning layer 1231, a reference layer 1232, a tunneling layer 1233, and a free layer 1234 stacked sequentially. The magnetization direction (also called the magnetic moment direction) of the pinning layer 1231 is parallel to the stacking direction of the layers in the MTJ. The first electrode 121 is located on the side of the free layer 1234 away from the pinning layer 1231, and the second electrode 122 is located on the side of the pinning layer 1231 away from the free layer 1234. Specifically, the first electrode 121 in the MTJ element 12 is electrically connected to the bit line BL, and the second electrode 122 is electrically connected to the drain or source of the transistor T; or, the first electrode 121 is electrically connected to the drain or source of the transistor T, and the second electrode 122 is electrically connected to the bit line BL. The following description uses the example of the first electrode 121 being electrically connected to the bit line BL, the second electrode 122 being electrically connected to the drain of transistor T, and the source of transistor T being electrically connected to the source line SL.

[0066] It should be understood that when the second electrode 122 or the first electrode 121 is electrically connected to the drain of transistor T, the source of transistor T is electrically connected to the data line. When the second electrode 122 or the first electrode 121 is electrically connected to the source of transistor T, the drain of transistor T is electrically connected to the data line.

[0067] It should be noted that the stacking direction of the layers in MTJ can be from pinned layer 1231 to free layer 1234, or from free layer 1234 to pinned layer 1231. (Appendix) Figure 3a and Figure 3b The arrows marked in pinned layer 1231 indicate the magnetization direction of pinned layer 1231. Taking the stacking direction of the layers in an MTJ as an example, pointing from pinned layer 1231 to free layer 1234, in this case, Figure 3a and Figure 3b The arrows marked on pinned layer 1231 can also indicate the stacking direction of each layer in the MTJ. Taking the stacking direction of each layer in the MTJ as pointing from pinned layer 1231 to free layer 1234 as an example, the magnetization direction of pinned layer 1231 parallel to the stacking direction of each layer in the MTJ can be that the magnetization direction of pinned layer 1231 is the same as the stacking direction of each layer in the MTJ, that is, the magnetization direction of pinned layer 1231 is pointing from pinned layer 1231 to free layer 1234; or the magnetization direction of pinned layer 1231 is parallel to and opposite to the stacking direction of each layer in the MTJ, that is, the magnetization direction of pinned layer 1231 is pointing from free layer 1234 to pinned layer 1231.

[0068] Furthermore, the reference layer 1232 is a film layer with a fixed magnetization direction in the MTJ. There is a strong ferromagnetic coupling between the pinning layer 1231 and the reference layer (also called the pinned layer) 1232. The magnetization direction of the reference layer 1232 can be pinned to a fixed direction by the pinning layer 1231, making it difficult to change. The magnetization direction of the reference layer 1232 is the same as that of the pinning layer 1231, and therefore, the magnetization direction of the reference layer 1232 is also parallel to the stacking direction of the layers in the MTJ. Moreover, since the pinning layer 1231 is used to pin the magnetization direction of the reference layer 1232 to a fixed direction, the magnetization direction of the pinning layer 1231 should not be easily changed; that is, the pinning layer 1231 should have a large coercive field. Due to the effect of the tunneling layer 1233, the reference layer 1232 and the free layer 1234 are in a decoupled state. Therefore, the magnetization direction of the free layer 1234 can easily change under the influence of an external magnetic field. The magnetization direction of the free layer 1234 and the magnetization direction of the reference layer 1232 can be parallel or antiparallel, that is, the magnetization direction of the free layer 1234 and the magnetization direction of the reference layer 1232 can be the same or opposite.

[0069] Based on the above, since the magnetization directions of the pinned layer 1231, the reference layer 1232, and the free layer 1234 are all parallel to the stacking direction of each layer in the MTJ, the MTJ in this embodiment is an MTJ with perpendicular magnetic anisotropy (PMA).

[0070] The aforementioned reference layer 1232 and free layer 1234 are magnetic layers. For example, the materials of reference layer 1232 and free layer 1234 include one or more of cobalt-iron-boron (CoFeB) alloy, cobalt-iron (CoFe) alloy, or nickel-iron-cobalt (NiFeCo) alloy. Taking the material of reference layer 1232 and free layer 1234 as a CoFeB alloy as an example, specifically, the materials of reference layer 1232 and free layer 1234 can be (Co... x Fe 1-x ) 1-y B y , where x and y are both between 0 and 0.30.

[0071] The tunneling layer 1233 is a non-magnetic layer. For example, the material of the tunneling layer 1233 includes one or more of magnesium oxide (MgO) or aluminum oxide (Al2O3).

[0072] To facilitate the growth of the pinning layer 1231, therefore in some embodiments, such as Figure 3bAs shown, the MTJ element 12 also includes a seed layer 1235 disposed between the second electrode 122 and the pinning layer 1231, on which the pinning layer 1231 can be grown.

[0073] Considering that the material of the reference layer 1232 is generally oriented 001 and the material of the pinning layer 1231 is generally oriented 111, due to the significant lattice difference between the reference layer 1232 and the pinning layer 1231, growing the reference layer 1232 on the pinning layer 1231 is difficult, leading to roughness accumulation, stress accumulation, etc. Therefore, in some embodiments, such as... Figure 3b As shown, the MTJ element 12 also includes a structure conversion layer 1236 disposed between the reference layer 1232 and the pinning layer 1231, and the structure conversion layer 1236 is made of an amorphous material.

[0074] Since the structure transformation layer 1236, which is located between the reference layer 1232 and the pinning layer 1231, is made of an amorphous material, and since amorphous materials do not have a fixed crystal orientation, growing the reference layer 1232 on the structure transformation layer 1236 can avoid growth difficulties caused by lattice differences, as well as problems such as roughness accumulation and stress accumulation.

[0075] For example, the material of the structural conversion layer 1236 is one or more of tantalum (Ta), tantalum alloy, and tantalum-tungsten alloy. Among them, tantalum is an amorphous material.

[0076] Based on this, in some embodiments, such as Figure 3b As shown, the MTJ element 12 also includes a capping layer 1237 disposed on the side of the free layer 1234 away from the tunneling layer 1233 and in contact with the free layer 1234. Here, the addition of the capping layer 1237 increases the vertical magnetic anisotropy of the free layer 1234 at the interface between the capping layer 1237 and the free layer 1234, thereby increasing the data retention time.

[0077] For example, the material of the cover layer 1237 includes magnesium oxide.

[0078] It should be understood that the tunneling layer 1233 is located between the reference layer 1232 and the free layer 1234. When reading the data stored in the MTJ element 12, more than 90% of the tunneling magnetoresistance (TMR) of the MTJ element 12 originates from the tunneling layer 1233. Therefore, the resistance of the tunneling layer 1233 should be set relatively high. The capping layer 1237 is located on the side of the free layer 1234 away from the tunneling layer 1233. The capping layer 1237 serves to increase the perpendicular magnetic anisotropy of the free layer 1234 and also facilitates current transmission. Therefore, the resistance of the capping layer 1237 should be set relatively low. In other words, the resistance of the tunneling layer 1233 is much greater than the resistance of the capping layer 1237. When both the tunneling layer 1233 and the capping layer 1237 are made of magnesium oxide, since the resistance of the tunneling layer 1233 is much greater than that of the capping layer 1237, the resistance of the capping layer 1237 can be reduced by adjusting its thickness. Alternatively, magnesium oxide can be formed through magnesium oxidation growth, which also results in magnesium oxide with lower resistance.

[0079] The key to enabling read and write operations in magnetic random access memory is to have a large tunneling magnetoresistance and a high spin-transfer efficiency. The MTJ structure described in this application can achieve a large tunneling magnetoresistance (150%-250%) and a high spin-transfer efficiency (>0.8), thus ensuring the read and write functionality.

[0080] Based on the structure of the memory 10 described above, the working process of the memory 10 will be introduced below using a memory cell 11 as an example.

[0081] When memory cell 11 is being written, transistor T is in the on state. When the current flows from the free layer 1234 to the reference layer 1232, that is, spin electrons flow from the reference layer 1232 to the free layer 1234, the electrons in the current are spin-polarized along the magnetization direction of the reference layer 1232 when passing through the reference layer 1232. The spin magnetic moment of the electrons is parallel to the magnetization direction of the reference layer 1232. When the electrons pass through the tunneling layer 1233 and reach the free layer 1234, the spin electrons will also... The spin angular momentum (STT) is transferred to the free layer 1234. Due to the spin moment effect, the free layer 1234 has a small magnetization, so the magnetization direction of the free layer 1234 can change freely according to the polarization direction of the spin electrons in the spin current. Ultimately, the magnetization direction of the free layer 1234 and the magnetization direction of the reference layer 1232 are parallel, that is, the magnetization direction of the free layer 1234 is the same as the magnetization direction of the reference layer 1232, which can represent that the written information is "0".

[0082] When the current flows from the reference layer 1232 to the free layer 1234, that is, when spin electrons flow from the free layer 1234 to the reference layer 1232, the spin electrons undergo exchange coupling with the magnetic moments in the reference layer 1232. Electrons with spins parallel to the magnetization direction of the reference layer 1232 pass through, while electrons with spins antiparallel to the magnetization direction of the reference layer 1232 are reflected. The reflected electrons pass through the tunneling layer 1233 to reach the free layer 1234, where they undergo exchange coupling with the magnetic moments of the free layer 1234. This causes the magnetization direction of the free layer 1234 to rotate in the opposite direction to the magnetization direction of the reference layer 1232. Ultimately, the magnetization direction of the free layer 1234 and the magnetization direction of the reference layer 1232 are antiparallel, meaning the magnetization direction of the free layer 1234 is opposite to that of the reference layer 1232. This can represent the written information being "1". The direction of the current here can be controlled by the voltage provided on the bit line BL and the source line SL. When the voltage provided by the bit line BL is greater than the voltage provided by the source line SL, the current flows from the free layer 1234 to the reference layer 1232; when the voltage provided by the bit line BL is less than the voltage provided by the source line SL, the current flows from the reference layer 1232 to the free layer 1234.

[0083] During reading from memory cell 11, a constant small current flows from bit line BL through MTJ to the drain of the conducting transistor T, creating a potential difference across MTJ. Based on the magnitude of this potential difference, the resistance of MTJ can be determined, i.e., the relative orientation of the magnetization directions of free layer 1234 and reference layer 1232 can be obtained, thus determining whether the information stored in memory cell 11 is "0" or "1". Specifically, if MTJ exhibits low resistance and the magnetization direction of free layer 1234 is parallel to that of reference layer 1232, the information stored in memory cell 11 is "0"; if MTJ exhibits high resistance and the magnetization direction of free layer 1234 is antiparallel to that of reference layer 1232, the information stored in memory cell 11 is "1".

[0084] It should be understood that when the memory 10 stores and reads information, the word line control circuit provides a strobe signal to the word line line by line, so that the transistors T in the multi-line memory cell 11 are turned on line by line, thereby enabling information to be written or read line by line.

[0085] Based on the working principle of the storage unit 11 described above, the memory 10 provided in this application embodiment can also be called a spin-shift magnetic random access memory.

[0086] refer to Figure 4a , Figure 5a as well as Figure 6a The aforementioned memory 10 may further include a substrate 13, on which transistors T, MTJ elements 12, and other patterns are disposed. (See attached image) Figure 4a , Figure 5aas well as Figure 6a The diagram uses a MOS transistor as an example, showing the source 141, drain 142, active layer 143, and gate 144 of transistor T. The gate insulating layer between the gate 144 and the active layer 143 is not shown.

[0087] It should be understood that in the fabrication process of memory 10, after the transistor T is fabricated on the substrate 13, the MTJ element 12 is not fabricated directly. Typically, after the transistor T is fabricated and before the MTJ element 12 is fabricated, other conductive functional patterns and insulating layers are formed (see attached diagram). Figure 4a , Figure 5a as well as Figure 6a (The conductive functional pattern and insulating layer are not shown). Based on this, in order to electrically connect the drain 142 of transistor T to the second electrode 122 in MTJ element 12, therefore, as Figure 4a , Figure 5a as well as Figure 6a As shown, in the current transmission path between the drain 142 of transistor T and MTJ element 12, at least one conductive structure 15 (also called a conductive tube or metal conductive tube) is connected in series between the second electrode 122 and the drain 142 of transistor T. The second electrode 122 is electrically connected to the drain 142 of transistor T through this at least one conductive structure 15. Similarly, after the MTJ element 12 is fabricated and before the bit line BL is fabricated, a conductive functional pattern and an insulating layer are also formed. Based on this, in order to electrically connect the first electrode 121 to the bit line BL, therefore, as shown... Figure 4a , Figure 5a as well as Figure 6a As shown, in the current transmission path between the MTJ element 12 and the bit line BL, at least one conductive structure 15 is connected in series between the first electrode 121 and the bit line BL, and the first electrode 121 is electrically connected to the bit line BL through the at least one conductive structure 15. The conductive structure 15 and the conductive functional pattern can be formed synchronously.

[0088] Based on this, such as Figure 4a , Figure 5a as well as Figure 6a As shown, the memory 10 provided in this application embodiment further includes a first magnetic structure 16 disposed on the current transmission path; wherein, the direction of the magnetic field (which can be called a static magnetic field or stray field) generated by the first magnetic structure 16 in the free layer 1234 is not parallel to the magnetization direction of the free layer 1234.

[0089] Compared to the prior art, the embodiments of this application add a first magnetic structure 16 to the current transmission path between the source 141 or drain 142 of transistor T and the bit line BL.

[0090] It should be understood that since the first magnetic structure 16 is disposed on the current transmission path between the source 141 or drain 142 of the transistor T and the bit line BL, the first magnetic structure 16 is conductive.

[0091] The following provides two exemplary implementations to achieve that the direction in which the first magnetic structure 16 generates a magnetic field in the free layer 1234 is not parallel to the magnetization direction of the free layer 1234.

[0092] In the first implementation, such as Figure 4a , Figure 5a as well as Figure 6a As shown, the memory also includes a connection layer 18 disposed between the first magnetic structure 16 and the MTJ element 12, wherein the first magnetic structure 16 is electrically connected to the MTJ element 12 through the connection layer 18; wherein the projection of the MTJ element 12 on the connection layer 18 and the projection of the first magnetic structure 16 on the connection layer 18 do not overlap in at least a portion of their areas.

[0093] In this embodiment, in some embodiments, the magnetization direction of the first magnetic structure 16 is parallel to the stacking direction of the layers in the MTJ.

[0094] It should be noted that, to ensure the magnetization direction of the first magnetic structure 16 remains unchanged after the external magnetic field is removed, for example, the magnetization direction of the first magnetic structure 16 is parallel to the stacking direction of the layers in the MTJ. That is, to make the first magnetic structure 16 have magnetic anisotropy, the length of the first magnetic structure 16 along the stacking direction parallel to the layers in the MTJ is greater than or equal to its length along the stacking direction perpendicular to the layers in the MTJ. When the first magnetic structure 16 is a cylinder, the height of the first magnetic structure 16 is greater than or equal to the diameter of the first magnetic structure 16.

[0095] Based on this, the direction of the magnetic field generated by the first magnetic structure 16 in the free layer 1234 can be adjusted by adjusting the magnetization direction of the first magnetic structure 16 and the relative position of the MTJ element 12 and the first magnetic structure 16 in the stacking direction perpendicular to the layers in the MTJ.

[0096] Furthermore, in some examples, the projections of the MTJ element 12 onto the connecting layer 18 and the projections of the first magnetic structure 16 onto the connecting layer 18 partially overlap, while partially not. In other examples, the projections of the MTJ element 12 onto the connecting layer 18 and the projections of the first magnetic structure 16 onto the connecting layer 18 do not overlap, meaning there is no overlapping area between them. The accompanying drawings of the embodiments in this application illustrate examples where the projections of the MTJ element 12 onto the connecting layer 18 and the projections of the first magnetic structure 16 onto the connecting layer 18 do not overlap.

[0097] In the second implementation, such as Figure 7a and Figure 7b As shown, the first magnetic structure 16 is in contact with the MTJ element 12, and the magnetization direction of the first magnetic structure 16 is perpendicular to the stacking direction of each layer in the MTJ.

[0098] Here, taking the stacking direction of each layer in MTJ as the vertical direction as an example, the magnetization direction of the first magnetic structure 16 can be horizontal to the left or horizontal to the right.

[0099] It should be understood that when the magnetization direction of the first magnetic structure 16 is perpendicular to the stacking direction of the layers in the MTJ, such as Figure 7a and Figure 7b As shown, the direction of the magnetic field generated by the first magnetic structure 16 in the free layer 1234 is perpendicular to the stacking direction of each layer in the MTJ.

[0100] It should be noted that, to ensure that the magnetization direction of the first magnetic structure 16 remains perpendicular to the stacking direction of the layers in the MTJ after the external magnetic field is removed, i.e., to ensure that the first magnetic structure 16 has magnetic anisotropy, the length of the first magnetic structure 16 along the stacking direction perpendicular to the layers in the MTJ is greater than or equal to its length along the stacking direction parallel to the layers in the MTJ. When the first magnetic structure 16 is a cylinder, its diameter is greater than or equal to its height.

[0101] Additionally, the aforementioned memory 10 may include a first magnetic structure 16, which in this case may be as follows: Figure 4a and Figure 4b As shown, the first magnetic structure 16 is connected between the MTJ element 12 and the source 141 or drain 142 of the transistor T. When the memory 10 includes a connection layer 18, the first magnetic structure 16 is electrically connected to the MTJ element 12 through the connection layer 18. Alternatively, it can be as follows... Figure 5a and Figure 5b As shown, the first magnetic structure 16 is connected between the MTJ element 12 and the bit line BL. When the memory 10 includes a connection layer 18, the first magnetic structure 16 is electrically connected to the MTJ element 12 through the connection layer 18. The memory 10 may also include two first magnetic structures 16, in which case, as shown... Figure 6a and Figure 6bAs shown, one first magnetic structure 16 is connected between the MTJ element 12 and the source 141 or drain 142 of the transistor T, and another first magnetic structure 16 is connected between the MTJ element 12 and the bit line BL. When the memory 10 includes a connection layer 18, the two first magnetic structures 16 are electrically connected to the MTJ element 12 through the two connection layers 18 respectively. The projections of these two first magnetic structures 16 onto the connection layer 18 may have overlapping areas or no overlapping areas. Figure 6a and Figure 6b The diagram is illustrated using the non-overlapping projection areas of the two first magnetic structures 16 on the connecting layer 18 as an example.

[0102] In some embodiments, the material of the first magnetic structure 16 includes one or more of elemental cobalt, elemental iron, elemental nickel, and alloys containing at least one of cobalt, iron, and nickel.

[0103] Among them, alloys containing at least one of cobalt, iron, and nickel can be, for example, CoB (cobalt-boron) alloys or FeB (iron-boron) alloys.

[0104] For example, the material of the aforementioned connecting layer 16 can be copper (Cu).

[0105] It is understandable that the material of the conductive structure 15 in the memory 10 is a non-magnetic material, such as copper.

[0106] It should be noted that, Figure 4a , Figure 4b , Figure 5a , Figure 5b , Figure 6a , Figure 6b , Figure 7a as well as Figure 7b The dashed curves in the figure represent the magnetic field lines of the first magnetic structure 16.

[0107] In some embodiments of this application, the first magnetic structure 16 can be formed by a via filling process. The specific process is as follows: first, an insulating layer is formed, the insulating layer including vias; next, a magnetic thin film is deposited; next, the magnetic thin film outside the vias is ground flat to form the first magnetic structure 16 in the vias.

[0108] also, Figure 4a , Figure 5a , Figure 6a as well as Figure 7aSome conductive layers 15 include a first conductive portion 151 and a second conductive portion 152. This is because when fabricating the conductive structure 15, an insulating layer is first formed, which includes vias. Next, a conductive film is formed. The portion of the conductive film deposited in the vias of the insulating layer is called the first conductive portion 151. The conductive film is patterned to form the aforementioned conductive functional pattern. At the same time, the portion of the conductive film deposited above the vias after patterning is called the second conductive portion 152.

[0109] Additionally, when the memory 10 includes a conductive structure 15 connected between the MTJ element 12 and the bit line BL, and in contact with the MTJ element 12, the conductive structure 15 can be as follows: Figure 4a As shown, it includes a first conductive part 151 and a second conductive part 152. The specific manufacturing process can be referred to the above, and will not be repeated here.

[0110] When the memory 10 includes a conductive structure 15 connected between the source 141 or drain 142 of the MTJ element 12 and the transistor T, and in contact with the MTJ element 12, the conductive structure 15 may include a first conductive portion 151 and a second conductive portion. The specific fabrication process can be referred to the above description and will not be repeated here. The conductive structure 15 can also be as follows: Figure 5a As shown, it includes a first conductive portion 151 but does not include a second conductive portion 152. The specific manufacturing process is as follows: first, an insulating layer is formed, which includes vias; next, a conductive film is formed; next, the conductive film outside the vias is removed (e.g., ground flat), and the conductive film deposited in the via portion of the insulating layer forms the first conductive portion 151, i.e., the conductive structure 15.

[0111] like Figure 4a As shown, when the memory 10 includes a first magnetic structure 16 connecting the source 141 or drain 142 of the MTJ element 12 and the transistor T, after the first magnetic structure 16 is fabricated, a conductive thin film is formed, the conductive thin film is patterned to form a connection layer 18, and then the MTJ element 12 is formed.

[0112] like Figure 5a As shown, when the memory 10 includes a first magnetic structure 16 connecting the MTJ element 12 and the bit line BL, after the MTJ element 12 is fabricated, a connection layer 18 is formed, followed by the formation of the first magnetic structure 16. The process of forming the connection layer 18 can be referred to the above and will not be repeated here. Based on this, after forming the first magnetic structure 16, the process of forming the conductive structure 15 can be as follows: Figure 5a and Figure 6aAs shown, a conductive thin film is formed, and the conductive thin film is patterned to form a conductive structure 15; alternatively, an insulating layer is first formed, which includes vias; then, a conductive thin film is formed, and the portion of the conductive thin film deposited in the vias of the insulating layer forms the first conductive portion 151 of the conductive structure 15. The conductive thin film is patterned to form the aforementioned conductive functional pattern, and the portion of the conductive thin film deposited above the vias after patterning forms the second conductive portion 152 of the conductive structure 15.

[0113] It should be understood that when the direction of the magnetic field generated by the first magnetic structure 16 in the free layer 1234 is perpendicular to the magnetization direction of the free layer 1234, the magnetic field generated by the first magnetic structure 16 in the free layer 1234 can apply a magnetic force to the free layer 1234 when it flips, which is beneficial to the flipping of the free layer 1234; when the direction of the magnetic field generated by the first magnetic structure 16 in the free layer 1234 is neither parallel nor perpendicular to the magnetization direction of the free layer 1234, the magnetic field component of the magnetic field generated by the first magnetic structure 16 in the free layer 1234 in the direction perpendicular to the stacking direction of each layer in the MTJ (also called the in-plane component), that is, the net in-plane field generated by the first magnetic structure 16 in the free layer 1234, can apply a magnetic force to the free layer 1234 when it flips, which is beneficial to the flipping of the free layer 1234.

[0114] This application provides a memory 10, which includes a plurality of memory cells 11 and a bit line BL. Each memory cell 11 includes a transistor T and an MTJ element 12 connected to the transistor T. The MTJ element 12 is disposed on the current transmission path between the source 141 or drain 142 of the transistor T and the bit line BL. The MTJ element 12 includes a pinning layer 1231, a reference layer 1232, a tunneling layer 1233, and a free layer 1234 stacked sequentially. The magnetization direction of the pinning layer 1231 is parallel to the stacking direction of each layer in the MTJ. The memory 10 also includes a first magnetic structure 16 disposed on the current transmission path. The direction of the magnetic field generated by the first magnetic structure 16 in the free layer 1234 is not parallel to the magnetization direction of the free layer 1234. Since the direction of the magnetic field generated by the first magnetic structure 16 in the free layer 1234 is not parallel to the magnetization direction of the free layer 1234, the magnetic field generated by the first magnetic structure 16 in the free layer 1234 can apply a magnetic force to the free layer 1234, which is beneficial to the flipping of the free layer 1234. In this way, the current required for the flipping of the free layer 1234 is reduced, the incubation time of STT is reduced, the flipping speed of the free layer 1234 is increased, the writing time is shortened, and the writing efficiency of the storage cell 11 is improved.

[0115] In some embodiments, the direction of the magnetic field generated by the first magnetic structure 16 in the free layer 1234 is perpendicular to the magnetization direction of the free layer 1234.

[0116] It should be understood that when the first magnetic structure 16 is electrically connected to the MTJ element 12 through the connecting layer 18, and the magnetization direction of the first magnetic structure 16 is parallel to the stacking direction of each layer in the MTJ, by adjusting the relative position of the MTJ element 12 and the first magnetic structure 16 in a direction perpendicular to the stacking direction of each layer in the MTJ, the direction of the magnetic field generated by the first magnetic structure 16 in the free layer 1234 can be perpendicular to the magnetization direction of the free layer 1234. When the magnetization direction of the first magnetic structure 16 is parallel to the stacking direction of each layer in the MTJ, the magnetization direction of the first magnetic structure 16 can be the same as or opposite to the magnetization direction of the pinning layer 1231.

[0117] Since the magnetic field generated by the first magnetic structure 16 in the free layer 1234 is perpendicular to the magnetization direction of the free layer 1234, the magnetic field generated by the first magnetic structure 16 in the free layer 1234 is larger and more conducive to the flipping of the free layer 1234. Therefore, the current required for the flipping of the free layer 1234 can be further reduced, and the incubation time of STT can be further reduced, thus more effectively improving the flipping speed of the free layer 1234.

[0118] refer to Figure 8a and Figure 8b , Figure 8a This is a schematic diagram for simulation. Figure 8a The box in the image represents the first magnetic structure 16, whose magnetization direction is parallel to the stacking direction of the layers in the MTJ. Figure 8a The diagram illustrates the direction of the magnetic field within the first magnetic structure 16 and the direction of the stray field generated externally. Figure 8a Arrows are used to indicate the direction of the magnetic field in the space where the first magnetic structure 16 is located. The direction of the magnetic field in the space where the first magnetic structure 16 is located includes the direction of the magnetic field inside the first magnetic structure 16 and the direction of the stray field generated outside. Figure 8a The black line A in the middle is parallel to the stacking direction of each layer in the MTJ. From Figure 8a As can be seen from the position indicated by the black line B, in-plane stray fields (i.e., stray fields with magnetic field directions perpendicular to the stacking directions of each layer in the MTJ) can be generated on both sides above the first magnetic structure 16 on the plane at the position indicated by the black line B. Figure 8b for Figure 8a The simulation result diagram of the plane at the position indicated by the black line B in the middle. Figure 8b The dashed circle in the diagram represents MTJ. According to... Figure 8b It can be seen that, in Figure 8aOn the plane indicated by the black line B, an in-plane stray field with an absolute value of approximately 3000e-800Oe is generated on both sides above the first magnetic structure 16. This stray field can be used to flip the free layer 1234. Furthermore, moving the MTJ ( Figure 8b The magnitude of the in-plane stray field generated by the first magnetic structure 16 on the MTJ can be selected by adjusting the relative position of the MTJ and the first magnetic structure 16 in a direction perpendicular to the stacking direction of each layer in the MTJ (e.g., the horizontal direction).

[0119] The current J required for the free layer 1234 to flip th The following formula can be used for calculation:

[0120] Among them, H X It is the in-plane field generated by the first magnetic structure 16 in the free layer 1234 (i.e., the magnetic field generated by the first magnetic structure 16 in the free layer 1234 is perpendicular to the stacking direction of each layer in the MTJ), H K,eff It is an effective anisotropic field, M S It is the saturation magnetization, t F η is the thickness of the free layer 1234, e is the electron constant, α is the magnetic damping coefficient, h is Planck's constant, and η is the spin transfer efficiency.

[0121] According to the above formula, the in-plane field generated by the first magnetic structure 16 in the free layer 1234 can significantly reduce the current required for the free layer 1234 to flip. At the same time, while the in-plane field acts on the magnetization direction of the free layer 1234, it enhances the effect of thermal disturbance, reduces the hatching time of STT, accelerates the flipping of the free layer 1234, reduces the write time of MTJ, and further reduces the dynamic write power consumption of MTJ.

[0122] Based on this, considering the magnetic field generated by the pinned layer 1231 in the free layer 1234, i.e., the stray field generated by the pinned layer 1231 in the free layer 1234, which will cause the free layer 1234 to generate a large compensation field, and may thus increase the current required for the free layer 1234 to flip. Therefore, to avoid the stray field generated by the pinned layer 1231 and increase the current required for the free layer 1234 to flip, two exemplary solutions are provided below.

[0123] Method 1: For example Figure 9 As shown, the pinning layer 1231 includes a first sub-pinning layer 1231a, a non-magnetic layer 1231b, and a second sub-pinning layer 1231c, which are stacked sequentially; the magnetization direction of the first sub-pinning layer 1231a is opposite to the magnetization direction of the second sub-pinning layer 1231c.

[0124] Here, as Figure 10 As shown, both the first sub-pinning layer 1231a and the second sub-pinning layer 1231c include ferromagnetic layers and heavy metal layers that are alternately stacked along the stacking direction of each layer in the MTJ.

[0125] It should be noted that the number of ferromagnetic and heavy metal layers in the first sub-pinning layer 1231a is different from the number of ferromagnetic and heavy metal layers in the second sub-pinning layer 1231c. For example, the first sub-pinning layer 1231a includes cobalt and platinum layers alternately stacked along the stacking direction of each layer in the MTJ, denoted as [Co / Pt]M, and the second sub-pinning layer 1231c includes cobalt and platinum layers alternately stacked along the stacking direction of each layer in the MTJ, denoted as [Co / Pt]N. M and N are both positive integers, representing the number of cobalt layers or the number of platinum layers, where M and N have different values.

[0126] In some embodiments, the material of the ferromagnetic layer includes one or more of elemental cobalt, elemental iron, elemental nickel, and alloys containing at least one of cobalt, iron, and nickel.

[0127] In some embodiments, the material of the heavy metal layer includes one or more of elemental platinum (Pt), elemental tantalum, elemental copper (Cu), elemental iridium (Ir), elemental ruthenium (Ru), elemental tungsten (W), and alloys containing at least one of platinum, tantalum, copper, iridium, ruthenium, and tungsten.

[0128] In some embodiments, the material of the non-magnetic layer 1231b includes one or more of elemental platinum, elemental tantalum, elemental copper, elemental iridium, elemental ruthenium, elemental tungsten, and alloys containing at least one of platinum, tantalum, copper, iridium, ruthenium, and tungsten.

[0129] It is understandable that if the first sub-pinning layer 1231a is closer to the reference layer 1232 than the second sub-pinning layer 1231c, then the magnetization direction of the reference layer 1232 is the same as the magnetization direction of the first sub-pinning layer 1231a; if the second sub-pinning layer 1231c is closer to the reference layer 1232 than the first sub-pinning layer 1231a, then the magnetization direction of the reference layer 1232 is the same as the magnetization direction of the second sub-pinning layer 1231c.

[0130] In this embodiment, since the pinning layer 1231 includes a first sub-pinning layer 1231a and a second sub-pinning layer 1231c, and the magnetization direction of the first sub-pinning layer 1231a is opposite to the magnetization direction of the second sub-pinning layer 1231c, the direction of the stray field generated by the first sub-pinning layer 1231a in the free layer 1234 is opposite to the direction of the stray field generated by the second sub-pinning layer 1231c in the free layer 1234. Therefore, the stray fields generated by the first sub-pinning layer 1231a in the free layer 1234 and the stray fields generated by the second sub-pinning layer 1231c in the free layer 1234 can cancel each other out. This can reduce or eliminate the influence of the stray field generated by the pinning layer 1231 in the free layer 1234 on the flipping of the free layer 1234, thereby reducing the current required for the flipping of the free layer 1234.

[0131] In some embodiments, the stray field generated by the first sub-pinning layer 1231a in the free layer 1234 is the same size as the stray field generated by the second sub-pinning layer 1231c in the free layer 1234. In this way, the stray fields generated by the first sub-pinning layer 1231a and the second sub-pinning layer 1231c in the free layer 1234 can completely cancel each other out, thereby further reducing the current required for the free layer 1234 to flip.

[0132] Method 2:

[0133] In some embodiments, such as Figure 11a and Figure 11b As shown, the memory 10 further includes a second magnetic structure 17 disposed on the current transmission path and in contact with the MTJ element 12; the angle between the magnetization direction of the second magnetic structure 17 and the magnetization direction of the pinning layer 1231 is (90°, 180°), that is, the angle between the magnetization direction of the second magnetic structure 17 and the magnetization direction of the pinning layer 1231 is greater than 90° and less than or equal to 180°.

[0134] Among them, such as Figure 11a and Figure 11b As shown, the first magnetic structure 16 is connected between the MTJ element 12 and the source 141 or drain 142 of the transistor T, and the second magnetic structure 17 is connected between the MTJ element 12 and the bit line BL; or, as... Figure 12a and Figure 12b As shown, the first magnetic structure 16 is connected between the MTJ element 12 and the bit line BL, and the second magnetic structure 17 is connected between the MTJ element 12 and the source 141 or drain 142 of the transistor T.

[0135] Here, the process of forming the second magnetic structure 17 can be the same as the process of forming the first magnetic structure 16 described above, and can be referred to above, so it will not be repeated here.

[0136] It should be understood that since the second magnetic structure 17 is disposed on the current transmission path between the source 141 or drain 142 of the transistor T and the bit line BL, the second magnetic structure 17 is conductive.

[0137] It is understood that since the angle between the magnetization direction of the second magnetic structure 17 and the magnetization direction of the pinning layer 1231 is (90°, 180°), the angle between the direction of the magnetic field generated by the second magnetic structure 17 in the free layer 1234 and the direction of the magnetic field generated by the pinning layer 1231 in the free layer 1234 is (90°, 180°).

[0138] Furthermore, when the direction of the magnetic field generated by the second magnetic structure 17 in the free layer 1234 is 180° away from the direction of the magnetic field generated by the pinning layer 1231 in the free layer 1234, that is, when the direction of the magnetic field generated by the second magnetic structure 17 in the free layer 1234 is opposite to the direction of the magnetic field generated by the pinning layer 1231 in the free layer 1234, the magnetic field generated by the second magnetic structure 17 in the free layer 1234 can cancel the magnetic field generated by the pinning layer 1231 in the free layer 1234, thus reducing the influence of the magnetic field generated by the pinning layer 1231 in the free layer 1234 on the free layer 1234. When the angle between the direction of the magnetic field generated by the second magnetic structure 17 in the free layer 1234 and the direction of the magnetic field generated by the pinning layer 1231 in the free layer 1234 is (90°, 180°), the second magnetic structure 17 will generate a magnetic field component in the free layer 1234 in the direction opposite to the magnetization direction of the pinning layer 1231. The magnetic field component generated by the second magnetic structure 17 in the free layer 1234 in the direction opposite to the magnetization direction of the pinning layer 1231 can cancel the magnetic field generated by the pinning layer 1231 in the free layer 1234.

[0139] In this embodiment, since the angle between the magnetization direction of the second magnetic structure 17 and the magnetization direction of the pinning layer 1231 is (90°, 180°), the magnetic field generated by the second magnetic structure 17 in the free layer 1234 can cancel the magnetic field generated by the pinning layer 1231 in the free layer 1234. This reduces or eliminates the compensation field generated by the free layer 1234, thereby reducing the current required for the free layer 1234 to flip and solving the problem of MTJ flipping asymmetry (i.e., the current required to change the magnetization direction of the free layer 1234 in opposite directions is different). Furthermore, since the magnetic field generated by the pinning layer 1231 in the free layer 1234 can be canceled by the magnetic field generated by the second magnetic structure 17 in the free layer 1234, it is not necessary to increase the current to overcome the difference in the influence of stray fields on the free layer 1234. In this way, the magnetization direction of the free layer 1234 can be flipped using a smaller current, which can reduce power and improve the durability and lifespan of the MTJ.

[0140] In some examples, the magnetization direction of the second magnetic structure 17 is opposite to that of the pinning layer 1231, and the magnetic field generated by the second magnetic structure 17 in the free layer 1234 is the same as the magnetic field generated by the pinning layer 1231 in the free layer 1234.

[0141] When the magnetization direction of the second magnetic structure 17 is opposite to that of the pinning layer 1231, and the magnetic field generated by the second magnetic structure 17 in the free layer 1234 is the same as that generated by the pinning layer 1231 in the free layer 1234, the magnetic field generated by the second magnetic structure 17 in the free layer 1234 can cancel the magnetic field generated by the pinning layer 1231 in the free layer 1234. Therefore, the magnetic field experienced by the free layer 1234 is zero or close to zero, and the compensation field generated by the magnetic field in the free layer 1234 is zero or close to zero. In this way, the current required for the free layer 1234 to flip is further reduced, and the problem of MTJ flipping asymmetry is solved more effectively.

[0142] Considering that the reference layer 1232 may also generate stray fields in the free layer 1234, in order to avoid the stray fields generated by the reference layer 1232 in the free layer 1234 increasing the current required for the free layer 1234 to flip, in some examples, the magnetization direction of the second magnetic structure 17 is opposite to the magnetization direction of the pinning layer 1231, and the magnetic field generated by the second magnetic structure 17 in the free layer 1234 is the same magnitude as the magnetic fields generated by the pinning layer 1231 and the reference layer 1232 in the free layer 1234. In this way, the magnetic fields generated by the pinning layer 1231 and the reference layer 1232 in the free layer 1234 can be canceled by the magnetic field generated by the second magnetic structure 17 in the free layer 1234, further reducing the current required for the free layer 1234 to flip.

[0143] refer to Figure 8a ,by Figure 8a The box in the image represents the second magnetic structure 17. The magnetization direction of the second magnetic structure 17 is parallel to the stacking direction of the layers in the MTJ. Figure 8a As shown by the black line A in the middle, the direction of the magnetic field inside the second magnetic structure 17 is opposite to the direction of the stray field generated externally. Figure 13 for Figure 8a The simulation results are shown in the figure, where the black lines A (Z-axis) and B (X-axis) indicate the positions. The horizontal axis represents the position of the X-axis or Z-axis. Figure 8a Point 'a' in the middle represents the Z-axis position as -5.00E-08. Figure 8a Point b in the middle represents the position on the X-axis as -5.00E-08. Figure 13 The vertical axis represents the magnetic field strength, measured in Oersted (Oe). Figure 13It can be seen that the magnetic field strength Hx changes along the X-axis and the magnetic field strength Hz changes along the Z-axis. Taking MTJ located above the second magnetic structure 17 as an example, Figure 8a The position P in the diagram represents the location of free layer 1234. Free layer 1234 is located at 20 nm on the Z-axis. Figure 13 The simulation results show that the second magnetic structure 17 generates a stray field of approximately 900 Oe to 2000 Oe at position P, and the direction of the stray field is opposite to the direction of the magnetic field within the second magnetic structure 17. Based on this, the stray field generated by the second magnetic structure 17 can be used to counteract the stray field generated by the pinning layer 1231.

[0144] Based on this, and according to method two, in order to reduce the thickness of the pinning layer 1231 and the thickness of the MTJ, therefore in some embodiments, such as Figure 10 As shown, the pinning layer 1231 includes ferromagnetic layers and heavy metal layers that are alternately stacked along the stacking direction of each layer in the MTJ.

[0145] For example, pinning layer 1231 includes cobalt layers and platinum layers ([Co / Pt]n, where n is a positive integer representing the number of cobalt layers or platinum layers) that are alternately stacked along the stacking direction of the layers in the MTJ.

[0146] It should be noted that the materials for the ferromagnetic layer and the heavy metal layer can be referenced above, and will not be repeated here.

[0147] Since the pinning layer 1231 consists only of alternating layers of ferromagnetic and heavy metal along the stacking direction of each layer in the MTJ, its thickness is significantly reduced, simplifying the structure. This is beneficial for reducing the roughness of the interface between the tunneling layer 1233 and the free layer 1234, reducing stress accumulation, and facilitating the miniaturization of the MTJ. Furthermore, the significantly reduced thickness of the pinning layer 1231, i.e., the reduced thickness of the conductive material beneath the tunneling layer 1233, lowers the probability of short circuits caused by backsplashing during etching, thus improving the engineering yield.

[0148] In other embodiments, the material of the pinning layer 1231 is a vertically magnetically anisotropic material.

[0149] For example, the material of the pinning layer 1231 includes one or more of iron-platinum (FePt) alloy and cobalt-platinum (CoPt) alloy.

[0150] Since the pinning layer 1231 is made of a perpendicularly magnetically anisotropic material, its magnetization direction can easily be magnetized parallel to the stacking direction of the layers in the MTJ. Therefore, the thickness of the pinning layer 1231 can be set to be smaller. This simplifies the structure, helps reduce the roughness of the interface between the tunneling layer 1233 and the free layer 1234, reduces stress accumulation, and facilitates the miniaturization of the MTJ. Furthermore, the significantly reduced thickness of the pinning layer 1231, i.e., the reduced thickness of the conductive material beneath the tunneling layer 1233, lowers the probability of short circuits caused by backsplashing during etching, thus improving the engineering yield.

[0151] It should be noted that the appendix to this application specification... Figure 4a , Figure 4b , Figure 5a , Figure 5b , Figure 6a , Figure 6b , Figure 7a , Figure 7b , Figure 11a , Figure 11b , Figure 12a as well as Figure 12b This diagram only illustrates the connection and positional relationship between the MTJ element 12 and the first magnetic structure 16 or the second magnetic structure 17, and does not limit the dimensional relationship between the MTJ element 12 and the first magnetic structure 16 or the second magnetic structure 17. Along a direction perpendicular to the stacking direction of the layers in the MTJ, the size of the first magnetic structure 16 or the second magnetic structure 17 may be greater than, equal to, or smaller than the size of the MTJ element 12.

[0152] Based on this, this application also provides an electronic device, which includes a circuit board and a memory connected to the circuit board. The memory can be any of the memory types described above. The circuit board can be a printed circuit board (PCB), or a flexible printed circuit board (FPC), etc. This embodiment does not limit the type of circuit board.

[0153] Optionally, the electronic device can be different types of user equipment or terminal equipment such as computers, mobile phones, tablets, wearable devices, and in-vehicle equipment; the electronic device can also be network equipment such as base stations. Optionally, the electronic device also includes a packaging substrate, which is fixed to the printed circuit board (PCB) by solder balls, and the memory is fixed to the packaging substrate by solder balls. It should be noted that for a detailed description of the memory in the electronic device, please refer to the description of the memory in the above embodiments, and it will not be repeated here.

[0154] Based on this, embodiments of this application also provide a non-transitory computer-readable storage medium for use with a computer having software for creating integrated circuits. The computer-readable storage medium stores one or more computer-readable data structures having photomask data for manufacturing the memory provided in any of the above-described figures.

[0155] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A memory, characterized in that, It includes multiple memory cells and bit lines arranged in an array within the memory region of the memory, wherein each memory cell includes a transistor and a magnetic tunnel junction (MTJ) element connected to the transistor; The MTJ element is disposed on the current transport path between the source or drain of the transistor and the bit line; the MTJ element includes a pinned layer, a reference layer, a tunneling layer and a free layer stacked sequentially; the magnetization direction of the pinned layer is parallel to the stacking direction of each layer in the MTJ; The memory further includes a first magnetic structure disposed on the current transmission path, and a connection layer disposed between the first magnetic structure and the MTJ element, wherein the first magnetic structure is electrically connected to the MTJ element through the connection layer; Wherein, the direction of the magnetic field generated by the first magnetic structure in the free layer is not parallel to the magnetization direction of the free layer, and the projection of the MTJ element on the connecting layer and the projection of the first magnetic structure on the connecting layer do not overlap in at least a portion of the area.

2. The memory according to claim 1, characterized in that, The direction of the magnetic field generated by the first magnetic structure in the free layer is perpendicular to the magnetization direction of the free layer.

3. The memory according to claim 1 or 2, characterized in that, The first magnetic structure is connected between the MTJ element and the source or drain of the transistor.

4. The memory according to claim 1 or 2, characterized in that, The first magnetic structure is connected between the MTJ element and the bit line.

5. The memory according to claim 1 or 2, characterized in that, The MTJ element further includes a first electrode and a second electrode; The first electrode is located on the side of the free layer away from the pinned layer, and the second electrode is located on the side of the pinned layer away from the free layer; The first electrode is electrically connected to the bit line, and the second electrode is electrically connected to the source or drain of the transistor; or, the first electrode is electrically connected to the source or drain of the transistor, and the second electrode is electrically connected to the bit line.

6. The memory according to claim 1 or 2, characterized in that, The material of the first magnetic structure includes one or more of elemental cobalt, elemental iron, elemental nickel, and alloys containing at least one of cobalt, iron, and nickel.

7. The memory according to claim 1 or 2, characterized in that, The pinning layer includes a first sub-pinning layer, a non-magnetic layer, and a second sub-pinning layer that are stacked sequentially. The magnetization direction of the first sub-pinning layer is opposite to that of the second sub-pinning layer.

8. The memory according to claim 7, characterized in that, Both the first sub-pinning layer and the second sub-pinning layer include ferromagnetic layers and heavy metal layers that are alternately stacked along the stacking direction of each layer in the MTJ.

9. The memory according to claim 8, characterized in that, The material of the ferromagnetic layer includes one or more of elemental cobalt, elemental iron, elemental nickel, and alloys containing at least one of cobalt, iron, and nickel; The material of the heavy metal layer includes one or more of the following: elemental platinum, elemental tantalum, elemental copper, elemental iridium, elemental ruthenium, elemental tungsten, and alloys containing at least one of platinum, tantalum, copper, iridium, ruthenium, and tungsten.

10. The memory according to claim 1 or 2, characterized in that, The memory also includes a second magnetic structure disposed on the current transmission path and in contact with the MTJ element; the magnetization direction of the second magnetic structure forms an angle (90°, 180°) with the magnetization direction of the pinning layer. Wherein, the first magnetic structure is connected between the MTJ element and the source or drain of the transistor, and the second magnetic structure is connected between the MTJ element and the bit line; or, the first magnetic structure is connected between the MTJ element and the bit line, and the second magnetic structure is connected between the MTJ element and the source or drain of the transistor.

11. The memory according to claim 10, characterized in that, The magnetization direction of the second magnetic structure is opposite to that of the pinned layer, and the magnetic field generated by the second magnetic structure in the free layer is the same as the magnetic field generated by the pinned layer in the free layer.

12. The memory according to claim 10, characterized in that, The pinning layer includes ferromagnetic layers and heavy metal layers that are alternately stacked along the stacking direction of each layer in the MTJ.

13. The memory according to claim 10, characterized in that, The pinning layer is made of a vertically magnetically anisotropic material.

14. The memory according to claim 13, characterized in that, The material of the pinning layer includes one or more of iron-platinum alloy and cobalt-platinum alloy.

15. The memory according to claim 1 or 2, characterized in that, The materials of the reference layer and the free layer include a cobalt-iron-boron (CoFeB) alloy. The material of the tunneling layer includes magnesium oxide (MgO).

16. The memory according to claim 1, characterized in that, The gate of the transistor is connected to the word line control circuit via the word line WL, and the source or drain of the transistor is connected to the data line; the bit line is connected to the bit line control circuit.

17. An electronic device, comprising a circuit board and a memory electrically connected to the circuit board, characterized in that, The memory is the memory as described in any one of claims 1-16.

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