Magnetic memory, magnetic memory cell and magnetic memory system

Abstract

The invention provides a magnetic memory, a magnetic memory unit and a magnetic memory system. The magnetic memory at least comprises a first antiferromagnetic layer, a free layer, a barrier layer, a reference layer and a second antiferromagnetic layer which are sequentially stacked from bottom to top, wherein the magnetic moment direction of the reference layer is a first direction, the magnetic moment direction of the free layer is a second direction, and the first direction is perpendicular to the second direction; when the magnetic memory is in a first mode, applying a current parallel to a second direction to the first antiferromagnetic layer, so that the magnetic moment direction of the free layer is changed from the second direction to a direction parallel to the first direction, and the magnetic memory is switched from the first mode to the second mode; the first mode is used for detecting a magnetic field around the magnetic memory; the second mode is used for data storage. Therefore, the magnetic memory can be switched from the sensing mode to the storage mode, and the occupied space and cost can be saved at the same time.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor technology, and in particular to a magnetic memory, a magnetic memory cell and a magnetic memory system. BACKGROUND

[0002] Magnetic Random Access Memory (MRAM) is a new type of non-volatile random memory using the principle of reading the size of magnetic resistance. Compared with other storage technologies (such as SRAM and DRAM), MRAM has the advantages of fast reading and writing, low power consumption, unlimited times of erasing and writing, and low cost.

[0003] Magnetic sensors can detect changes in physical quantities related to magnetic fields or magnetic fields themselves, and are a major branch of the modern sensor industry. Among them, TMR (Tunneling Magneto Resistance) sensors are one of the most advanced magnetic sensors. TMR sensors work based on the magnetic tunnel junction effect, and have the advantages of high sensitivity, low power consumption and miniaturization, and are widely used in high-precision magnetic field detection and biomedical fields.

[0004] In electronic devices, in addition to the need to set MRAM, sensors such as TMR sensors also need to be set to detect magnetic fields. Currently, MRAM and TMR sensors exist independently in electronic devices, and the independently set MRAM and TMR sensors need additional silicon chips and interconnection structures when they are independently integrated, resulting in a larger occupied space and higher cost. SUMMARY

[0005] The present application provides a magnetic memory, a magnetic memory cell and a magnetic memory system, which can convert a magnetic memory in a mode of detecting a magnetic field into a mode of storing data, and can save space and cost at the same time.

[0006] In a first aspect, the present application provides a magnetic memory, comprising a first antiferromagnetic layer, a free layer, a barrier layer, a reference layer and a second antiferromagnetic layer stacked in order from bottom to top; wherein the magnetic moment direction of the reference layer is a first direction, and the magnetic moment direction of the free layer is a second direction, and the first direction is perpendicular to the second direction.

[0007] When the magnetic memory is in a first mode, an electric current parallel to the second direction is applied to the first antiferromagnetic layer, so that the magnetic moment direction of the free layer changes from the second direction to a direction parallel to the first direction, and the magnetic memory is switched from the first mode to a second mode.

[0008] The first mode is used for detecting a magnetic field around the magnetic memory, and the second mode is used for data storage.

[0009] In a possible implementation, the first antiferromagnetic layer is a cross structure.

[0010] When the magnetic memory is in the second mode, a current parallel to the first direction is applied to the first antiferromagnetic layer, so that the magnetic moment direction of the free layer changes from parallel to the first direction to parallel to the second direction, and the magnetic memory is switched from the second mode to the first mode.

[0011] In a possible implementation, the first antiferromagnetic layer is a rectangular structure, and the direction of the current applied to the first antiferromagnetic layer is parallel to the second direction.

[0012] In a possible implementation, when the magnetic memory is in the first mode and a magnetic field parallel to the first direction exists around the magnetic memory, the magnetic moment direction of the free layer deflects by a target angle under the influence of the magnetic field; the target angle is used to determine the size of the magnetic field and is positively correlated with the size of the magnetic field.

[0013] In a possible implementation, the magnetic moment direction of the reference layer and the magnetic moment direction of the free layer are obtained by sequentially performing a first annealing process and a second annealing process on an initial state of the magnetic memory in advance;

[0014] The first annealing process comprises annealing the initial state of the magnetic memory by using a magnetic field with a first annealing temperature and a first annealing direction, so that the pinning direction of the first antiferromagnetic layer and the pinning direction of the second antiferromagnetic layer are both the first annealing direction.

[0015] The first annealing temperature is greater than the blocking temperature of the first antiferromagnetic layer and greater than the blocking temperature of the second antiferromagnetic layer; and the first annealing direction is the first direction.

[0016] The second annealing process comprises annealing the magnetic memory after the first annealing process by using a magnetic field with a second annealing temperature and a second annealing direction, so that the magnetic moment direction of the free layer changes to the second annealing direction.

[0017] The second annealing temperature is greater than the blocking temperature of the first antiferromagnetic layer and less than the blocking temperature of the second antiferromagnetic layer; and the second annealing direction is the second direction.

[0018] In a possible implementation, the magnetic moment direction of the reference layer and the magnetic moment direction of the free layer are obtained by sequentially performing an annealing process and a free layer preprocessing on an initial state of the magnetic memory in advance;

[0019] The annealing process comprises: annealing the magnetic memory in an initial state using a magnetic field with a first annealing temperature and a first annealing direction, so that the pinning direction of the first antiferromagnetic layer and the pinning direction of the second antiferromagnetic layer are both the first annealing direction;

[0020] The first annealing temperature is greater than the blocking temperature of the first antiferromagnetic layer and greater than the blocking temperature of the second antiferromagnetic layer; and the first annealing direction is the first direction.

[0021] The free layer preprocessing comprises: after the annealing process, applying a current parallel to the first direction to the first antiferromagnetic layer, so that the magnetic moment direction of the free layer becomes the second direction.

[0022] In a second aspect, the embodiments of the present application provide a magnetic storage unit, which comprises at least four magnetic memories as described in the first aspect and / or various possible implementation manners of the first aspect to form a Wheatstone bridge.

[0023] The Wheatstone bridge comprises at least one first magnetic memory in the first mode and at least one second magnetic memory in the second mode.

[0024] When a magnetic field exists around the Wheatstone bridge, the strength of the magnetic field is determined according to the voltage value of the voltage node of the Wheatstone bridge.

[0025] In a possible implementation manner, each Wheatstone bridge comprises two first magnetic memories and two second magnetic memories.

[0026] The two first magnetic memories are used as two bridge arms arranged diagonally in the Wheatstone bridge, and the two second magnetic memories are used as two bridge arms arranged diagonally in the Wheatstone bridge.

[0027] When a magnetic field parallel to the first direction exists around the Wheatstone bridge, the direction of the magnetic field is determined according to the positive and negative of the voltage value of the voltage node of the Wheatstone bridge, and the strength of the magnetic field is determined according to the magnitude of the voltage value.

[0028] When a magnetic field parallel to the second direction exists around the Wheatstone bridge, the strength of the magnetic field is determined according to the magnitude of the voltage value of the voltage node of the Wheatstone bridge.

[0029] In a possible implementation manner, each Wheatstone bridge comprises three first magnetic memories and one second magnetic memory, or one first magnetic memory and three second magnetic memories.

[0030] When a magnetic field parallel to the first direction exists around the Wheatstone bridge, the direction of the magnetic field strength is determined according to the positive and negative of the voltage value of the voltage node of the Wheatstone bridge, and the size of the magnetic field strength is determined according to the size of the voltage value.

[0031] When a magnetic field parallel to the second direction exists around the Wheatstone bridge, the size of the magnetic field strength is determined according to the size of the voltage value of the voltage node of the Wheatstone bridge.

[0032] The magnetic memory provided by the application comprises a first antiferromagnetic layer, a free layer, a barrier layer, a reference layer and a second antiferromagnetic layer stacked from bottom to top; wherein the magnetic moment direction of the reference layer is the first direction, the magnetic moment direction of the free layer is the second direction, and the first direction is perpendicular to the second direction; when the magnetic memory is in the first mode, a current parallel to the second direction is applied to the first antiferromagnetic layer, so that the magnetic moment direction of the free layer changes from the second direction to a direction parallel to the first direction, and the magnetic memory is switched from the first mode to the second mode; the first mode is used for detecting the magnetic field around the magnetic memory; and the second mode is used for data storage. In this way, when the magnetic moment direction of the reference layer and the magnetic moment direction of the free layer of the magnetic memory are perpendicular, the magnetic memory is in a mode capable of detecting the magnetic field around the magnetic memory, and at this time, the magnetic memory can be regarded as a sensor. For the magnetic memory in this mode, a current can be applied to make the magnetic moment direction of the reference layer and the magnetic moment direction of the free layer parallel, so that the magnetic memory changes to a mode capable of storing data. Therefore, the magnetic memory of the application synchronously integrates the sensing and storage modes, and can also be switched from the sensing mode to the storage mode, so that the sensor separately arranged in the electronic device can be removed, thereby saving the occupied space and device cost, and in the process, an additional silicon wafer and interconnection structure do not need to be prepared for the sensor, further reducing the process cost.

[0033] In a third aspect, the embodiments of the application provide a magnetic storage system, comprising a conventional storage array, a storage area and a magnetic field detection area;

[0034] The storage area comprises at least one magnetic memory in the second mode as described in the first aspect and / or various possible implementation manners of the first aspect, and i magnetic memories in the first mode as described in the first aspect and / or various possible implementation manners of the first aspect; i is an integer greater than or equal to 0;

[0035] The magnetic field detection area comprises at least one magnetic memory in the first mode as described in the first aspect and / or various possible implementation manners of the first aspect, and j magnetic memories in the second mode as described in the first aspect and / or various possible implementation manners of the first aspect; j is an integer greater than or equal to 0;

[0036] When the magnetic field intensity detected by the magnetic memory in the magnetic field detection area is greater than or equal to a preset magnetic field intensity, a current parallel to the second direction is applied to the first antiferromagnetic layer of the i magnetic memories in the storage area in the first mode, so that the magnetic moment direction of the free layer changes from the second direction to a direction parallel to the first direction, and the magnetic memory is switched from the first mode to the second mode;

[0037] Data in the conventional storage array is written into the magnetic memory in the storage area.

[0038] The magnetic storage system provided by the application comprises a conventional storage array, a storage area and a magnetic field detection area; wherein the storage area comprises at least one magnetic memory in a second mode and i magnetic memories in a first mode, i is an integer greater than or equal to 0, the magnetic field detection area comprises at least one magnetic memory in the first mode and j magnetic memories in the second mode, j is an integer greater than or equal to 0; the magnetic memory comprises a first antiferromagnetic layer, a free layer, a barrier layer, a reference layer and a second antiferromagnetic layer stacked from bottom to top; wherein the magnetic moment direction of the reference layer is a first direction, the magnetic moment direction of the free layer is a second direction, and the first direction is perpendicular to the second direction; when the magnetic memory is in the first mode, a current parallel to the second direction is applied to the first antiferromagnetic layer, so that the magnetic moment direction of the free layer changes from the second direction to a direction parallel to the first direction, and the magnetic memory is switched from the first mode to the second mode; the first mode is used for detecting the magnetic field around the magnetic memory; the second mode is used for data storage. In this way, the magnetic memory in the magnetic storage system of the application can be synchronously integrated with the sensing and storage modes, and can be switched from the sensing mode to the storage mode, so that the sensor separately arranged in the electronic device can be removed, thereby saving the occupied space and device cost, and in the process, no additional silicon wafer and interconnection structure need to be prepared for the sensor, further reducing the process cost; and when the magnetic field intensity detected by the magnetic memory in the magnetic field detection area is greater than or equal to a preset magnetic field intensity, a current parallel to the second direction is applied to the first antiferromagnetic layer of the i magnetic memories in the storage area in the first mode, so that the magnetic memory is switched from the first mode to the second mode, and data in the conventional storage array is written into the magnetic memory in the storage area in the second mode, so that the data will not be damaged under a strong external magnetic field, and the safety of the data is enhanced. BRIEF DESCRIPTION OF DRAWINGS

[0039] The accompanying drawings, which are incorporated into and form a part of the specification, illustrate an embodiment consistent with the application and, together with the specification, serve to explain the principles of the application.

[0040] Figure 1 A structure diagram of a magnetic memory provided by the embodiment of the application;

[0041] Figure 2 Another structure diagram of a magnetic memory provided by an embodiment of the present application;

[0042] Figure 3 A structure diagram of a magnetic memory after a first annealing process provided by an embodiment of the present application;

[0043] Figure 4 A structure diagram of a magnetic memory after a second annealing process provided by an embodiment of the present application;

[0044] Figure 5 A structure diagram of a magnetic memory in a high resistance state provided by an embodiment of the present application;

[0045] Figure 6 A structure diagram of a magnetic memory in a low resistance state provided by an embodiment of the present application;

[0046] Figure 7 A method flow diagram of switching a first mode to a second mode provided by an embodiment of the present application;

[0047] Figure 8 A structure diagram of a magnetic memory switching between a first mode and a second mode provided by an embodiment of the present application;

[0048] Figure 9 A method flow diagram of a magnetic memory switching between a first mode and a second mode provided by an embodiment of the present application;

[0049] Figure 10 A hysteresis loop diagram of a magnetic memory in different modes provided by an embodiment of the present application;

[0050] Figure 11 A structure diagram of a magnetic storage unit provided by an embodiment of the present application;

[0051] Figure 12 Another structure diagram of a magnetic storage unit provided by an embodiment of the present application;

[0052] Figure 13 A flow diagram of data storage transfer provided by an embodiment of the present application;

[0053] Figure 14 A timing diagram in a data migration scenario provided by an embodiment of the present application;

[0054] Figure 15 A flow diagram of a mode switching method of a magnetic storage system provided by an embodiment of the present application.

[0055] Reference signs:

[0056] 11: second antiferromagnetic layer; 12: reference layer; 13: barrier layer; 14: free layer; 15: first antiferromagnetic layer; 16: pinned layer; 17: coupling layer; 18: decoupling layer; 19: soft magnetic layer.

[0057] The specific embodiments of the application have been shown by way of example in the above figures, and will be described in more detail hereafter. These figures and this written description are not intended to limit the scope of the inventive concept in any way, but rather to illustrate the inventive concept to one of ordinary skill in the art by reference to specific embodiments. DETAILED DESCRIPTION

[0058] The exemplary embodiments will be described in detail herein with reference to the attached drawings. The description of the exemplary embodiments is intended to apply to any embodiment of the application, unless specified otherwise. It should be understood that every embodiment need not necessarily include all of the features shown in the drawings or all of the components described in the text, but is intended to include only those features, components or steps that are specifically set forth or otherwise deliberately excluded. Moreover, it should be understood that the description of the exemplary embodiments is intended solely to be illustrative of the inventive concept, and not to be limiting of the scope of the application, as set forth in the appended claims.

[0059] In an electronic device, in addition to the need to set up an MRAM, a sensor such as a TMR sensor also needs to be set up to detect a magnetic field.

[0060] At present, the MRAM and the TMR sensor exist independently in the electronic device, the MRAM can only be used for data storage, and the independently integrated MRAM and TMR sensor need additional silicon chips and interconnection structures, resulting in a large occupied space and high cost.

[0061] Based on this, the application provides a magnetic memory, which comprises a first antiferromagnetic layer, a free layer, a barrier layer, a reference layer and a second antiferromagnetic layer stacked in order from bottom to top. By controlling the magnetic moment direction of the reference layer and the free layer of the magnetic tunnel junction in the magnetic memory, the magnetic memory is controlled to be in a sensing mode or a storage mode. When the magnetic memory is in the sensing mode capable of detecting a magnetic field, the magnetic moment direction of the free layer can be changed by applying a current to the first antiferromagnetic layer, so that the magnetic memory becomes a storage mode capable of storing data. In this way, the magnetic memory of the application can synchronously integrate the sensing and storage modes, and can also switch from the sensing mode to the storage mode, so that the separately set sensor in the electronic device can be removed, thereby saving the occupied space and device cost, and in the process, no additional silicon chips and interconnection structures need to be prepared for the sensor, further reducing the process cost.

[0062] The technical solutions of the present application and how the technical solutions of the present application solve the above technical problems will be described in detail below with specific examples. The following specific examples can be combined with each other, and the same or similar concepts or processes can not be described again in some examples. The embodiments of the present application will be described below with reference to the accompanying drawings.

[0063] Figure 1 A structure diagram of a magnetic memory provided by an embodiment of the present application is shown in the figure.

[0064] As shown in the figure, the magnetic memory includes, from top to bottom, a second antiferromagnetic layer 11, a reference layer 12, a barrier layer 13, a free layer 14, and a first antiferromagnetic layer 15. Figure 1

[0065] The magnetic tunnel junction (MTJ) includes the free layer 14, the barrier layer 13, and the reference layer 12, and the barrier layer 13 is sandwiched between the free layer 14 and the reference layer 12.

[0066] For example, in the magnetic memory provided by the embodiment of the present application, the materials of the first antiferromagnetic layer 15 and the second antiferromagnetic layer 11 can be one or more combinations of IrMn, PtMn, FeMn, PdMn, Mn3Sn, Mn3Pt, Mn3Ir, Mn3Ge, etc.

[0067] The barrier layer 13 can be an insulator, such as MgO, Al2O3, or other oxides.

[0068] The materials of the free layer 14 and the reference layer 12 can include the following two possible implementations:

[0069] In one possible implementation, the free layer 14 and the reference layer 12 can be ferromagnetic materials or ferrimagnetic materials.

[0070] The ferromagnetic materials can be one or more combinations of Co, Fe, Ni, CoFe, CoFeB, FeB, CoB, NiFe, etc. The ferrimagnetic materials can be one or more combinations of GdFeCo, CdFe, CoTb, etc.

[0071] In another possible implementation, the free layer 14 and the reference layer 12 can also be a composite layer, for example, composed of two magnetic layers, and a layer of metal, such as Ru, W, Mo, Ta, Ir, etc., is interposed in the middle.

[0072] The embodiment of the present application does not make specific limitations on the materials of the first antiferromagnetic layer 15, the free layer 14, the barrier layer 13, the reference layer 12, and the second antiferromagnetic layer 11.

[0073] As shown in the figure, the magnetic memory includes, from top to bottom, a second antiferromagnetic layer 11, a reference layer 12, a barrier layer 13, a free layer 14, and a first antiferromagnetic layer 15. Figure 1 ​The magnetic memory shown can be in a first mode for detecting a magnetic field around the magnetic memory, or in a second mode for data storage.

[0074] When the magnetic moment direction of the reference layer 12 is in a first direction, the magnetic moment direction of the free layer 14 is in a second direction, and the first direction is perpendicular to the second direction, the magnetic memory is in the first mode. At this time, by applying a current parallel to the second direction to the first antiferromagnetic layer 15, the magnetic moment direction of the free layer 14 can be changed from the second direction to a direction parallel to the first direction, and the magnetic memory is switched from the first mode to the second mode.

[0075] Before the magnetic memory of the embodiment of the present application is specifically described, first, the working principle of the two modes of the magnetic memory of the present application is described.

[0076] When the magnetic memory is in the first mode, it is equivalent to a sensor, and can be used to detect a magnetic field around the magnetic memory.

[0077] To realize the linear output of the sensor, the magnetization directions of the free layer 14 and the reference layer 12 need to be perpendicular to each other. The first antiferromagnetic layer 15 and the second antiferromagnetic layer 11 are respectively used to fix the magnetization directions of the magnetic moments of the reference layer 12 and the free layer 14, so that they are in a perpendicular state. Since the blocking temperature of the second antiferromagnetic layer 11 is higher than that of the first antiferromagnetic layer 15, the pinning effect of the second antiferromagnetic layer 11 on the reference layer 12 is greater than that of the first antiferromagnetic layer 15 on the free layer 14. Therefore, the direction of the magnetic moment of the reference layer 12 will not change with an applied magnetic field, and the magnetic moment of the free layer 14 can be flipped under the action of the applied magnetic field.

[0078] The blocking temperature (Tb) is the temperature at which the exchange biasing effect of the ferromagnetic layer and the antiferromagnetic layer disappears. When the annealing temperature exceeds the blocking temperature, the magnetic order of the antiferromagnetic layer becomes disordered, and loses the pinning effect on the ferromagnetic layer.

[0079] The working principle of the sensor is as follows: when there is a magnetic field around the sensor, the magnetic moment direction of the free layer 14 will change, the tunneling probability of the electrons will change, and the resistance value will change accordingly. By detecting the resistance change of the magnetic tunnel junction, the external magnetic field can be detected.

[0080] Based on the above, when the magnetic memory is in the first mode, a current parallel to the second direction is applied to the first antiferromagnetic layer 15 to change the magnetic moment direction of the free layer 14 from the second direction to a direction parallel to the first direction, and the magnetic memory is switched from the first mode to the second mode, which is a storage mode.

[0081] In the storage mode, the magnetic moments of the reference layer 12 and the free layer 14 in the magnetic memory are parallel or anti-parallel. The first anti-ferromagnetic layer 15 and the second anti-ferromagnetic layer 11 are used to fix the magnetization directions of the magnetic moments of the reference layer 12 and the free layer 14 respectively, so that the magnetic moments are in the parallel or anti-parallel state.

[0082] The principle of data storage of the magnetic memory is that there is exchange coupling between the interface of the first anti-ferromagnetic layer 15 and the free layer 14 to form an exchange bias field (EB), and then the magnetic moment direction of the free layer 14 is pinned. By passing a write current to the first anti-ferromagnetic layer 15, the exchange bias field of the first anti-ferromagnetic layer 15 and the free layer 14 is flipped to a direction perpendicular to the current, so that the magnetic moment direction of the free layer 14 is also flipped to a direction perpendicular to the current. When the magnetic moment direction of the free layer 14 is parallel to the magnetic moment direction of the reference layer 12, the magnetic tunnel junction is in a low resistance state; when the magnetic moment directions of the two are anti-parallel, the magnetic tunnel junction is in a high resistance state.

[0083] The two resistance states of the magnetic tunnel junction are used to represent binary data, and the low resistance state is usually defined as "1" and the high resistance state is defined as "0". In this way, by applying a write current to the first anti-ferromagnetic layer 15 to control the magnetic moment direction of the free layer 14, data storage is achieved.

[0084] In this application, in addition to the above-mentioned Figure 1 layers, other layers can also be included, which can be seen from Figure 2 , Figure 2 Another structure of a magnetic memory provided by an embodiment of the application is shown in the figure.

[0085] As Figure 2 shown, the magnetic memory can further include a pinned layer 16 and a coupling layer 17 between the second anti-ferromagnetic layer 11 and the reference layer 12, and a decoupling layer 18 and a soft magnetic layer 19 between the free layer 14 and the first anti-ferromagnetic layer 15.

[0086] The pinned layer 16 is above the coupling layer 17. The decoupling layer 18 is above the soft magnetic layer 19.

[0087] The function of the pinned layer 16 is to cancel the stray field generated by the reference layer 12, and the material can be one or a combination of Co, Fe, Ni, CoFe, CoFeB, FeB, CoB, NiFe, etc.

[0088] The pinned layer 16, the coupling layer 17 and the reference layer 12 form an artificial synthetic anti-ferromagnetic structure, and the function of the coupling layer 17 is to provide anti-ferromagnetic coupling for the artificial synthetic anti-ferromagnetic structure, and the material can be Ru, Ir, etc.

[0089] The soft magnetic layer 19 is used to reduce the coercive force, so that the free layer 14 is more likely to be flipped. The soft magnetic layer 19 can be made of NiFe, FeSiB, CoFeBSi, or the like.

[0090] The decoupling layer 18 is used to prevent the material of the soft magnetic layer 19 from affecting the crystallization process of the free layer 14, and further affecting the tunneling magnetoresistance of the magnetic tunnel junction. The decoupling layer 18 can be made of Ru, W, Mo, Ta, Ir, or the like.

[0091] It should be noted that the shape of the magnetic tunnel junction can be circular, or elliptical, rectangular, square, triangular, polygonal, etc., which are not limited in the embodiments of the present application.

[0092] In the present application, the magnetic memory can be in the first mode or the second mode.

[0093] When the magnetic memory is in the first mode, the magnetic moment direction of the reference layer 12 and the magnetic moment direction of the free layer 14 are perpendicular. When the magnetic memory is in the second mode, the magnetic moment direction of the reference layer 12 and the magnetic moment direction of the free layer 14 are parallel or anti-parallel.

[0094] Since the magnetic moments of the free layer 14 and the reference layer 12 in the initial state of the magnetic memory are usually disordered, the magnetic memory needs to be processed in advance, so that the magnetic moment direction of the reference layer 12 is the first direction, and the magnetic moment direction of the free layer 14 is the second direction, the first direction is perpendicular to the second direction, and the magnetic memory is in the first mode.

[0095] In the present application, the magnetic memory can be in the first mode by the following two possible implementations, i.e., the magnetic moment direction of the reference layer 12 and the magnetic moment direction of the free layer 14 are perpendicular.

[0096] One possible implementation is that the magnetic moment direction of the reference layer 12 and the magnetic moment direction of the free layer 14 are obtained by sequentially performing a first annealing process and a second annealing process on the magnetic memory in advance.

[0097] The first annealing process includes annealing the initial state of the magnetic memory using a magnetic field with a first annealing temperature and a first annealing direction, so that the pinning direction of the first anti-ferromagnetic layer 15 and the pinning direction of the second anti-ferromagnetic layer 11 are both the first annealing direction. The first annealing temperature is greater than the blocking temperature of the first anti-ferromagnetic layer 15, and is greater than the blocking temperature of the second anti-ferromagnetic layer 11; the first annealing direction is the first direction.

[0098] Due to the exchange bias effect between the anti-ferromagnetic layer and the ferromagnetic layer, the magnetic moment direction of the ferromagnetic layer adjacent to the anti-ferromagnetic layer is along the pinning direction of the anti-ferromagnetic layer.

[0099] For the magnetic memory in the first mode, the magnetic moment direction of the reference layer 12 is the first direction, and the magnetic moment direction of the free layer 14 is the second direction, which are perpendicular. Figure 1In the magnetic memory structure shown, the free layer 14 and the reference layer 12 are adjacent to the first antiferromagnetic layer 15 and the second antiferromagnetic layer 11, respectively. After the first annealing process, the pinning direction of the first antiferromagnetic layer 15 and the pinning direction of the second antiferromagnetic layer 11 are both the first annealing direction. Under the effect of exchange bias, the magnetic moment directions of the free layer 14 and the reference layer 12 are also both the first annealing direction.

[0100] for Figure 2 In the magnetic memory structure shown, the soft magnetic layer 19 and the pinned layer 16 are adjacent to the first antiferromagnetic layer 15 and the second antiferromagnetic layer 11, respectively. After the first annealing treatment, the pinning directions of the first antiferromagnetic layer 15 and the second antiferromagnetic layer 11 are both the first annealing direction. Under the effect of exchange bias, the magnetic moment directions of the soft magnetic layer 19 and the pinned layer 16 are also both the first annealing direction. Since there is an antiferromagnetic coupling between the pinned layer 16 and the reference layer 12, the magnetic moment direction of the reference layer 12 is opposite to the first annealing direction. There is no antiferromagnetic coupling between the soft magnetic layer 19 and the free layer 14, and the magnetic moment direction of the free layer 14 is the same as that of the soft magnetic layer 19, both being the first annealing direction. The magnetic moment direction of each film layer in this magnetic memory after the first annealing treatment can be referenced. Figure 3 As shown.

[0101] Below, with Figure 2 Taking the magnetic storage structure shown as an example, we will explain various cases of magnetic storage.

[0102] Figure 3 This is a schematic diagram of a magnetic storage device after a first annealing process, provided as an embodiment of this application.

[0103] It needs to be explained that, Figure 3 The example given is based solely on the Y-direction and does not constitute any limitation.

[0104] like Figure 3 As shown, the entire magnetic tunnel junction of the magnetic memory undergoes a first annealing process. The annealing magnetic field direction is along the Y direction, and the annealing temperatures are T>Tb2>Tb1. Here, T is the first annealing temperature, Tb1 is the barrier temperature of the first antiferromagnetic layer 15, and Tb2 is the barrier temperature of the second antiferromagnetic layer 11. Figure 3 As shown, by applying the first annealing treatment, the pinning directions of the first antiferromagnetic layer 15 and the second antiferromagnetic layer 11 are both along the Y direction, the magnetic moment directions of the soft magnetic layer 19 and the free layer 14 are along the Y direction, the magnetic moment direction of the pinned layer 16 is along the Y direction, and the magnetic moment direction of the reference layer 12 is along the negative direction of the Y direction under the action of the antiferromagnetic coupling of the pinned layer 16.

[0105] The second annealing process includes annealing the magnetic memory after the first annealing process by using a magnetic field with a second annealing temperature and a second annealing direction, so that the magnetic moment direction of the free layer 14 becomes the second annealing direction. The second annealing temperature is greater than the blocking temperature of the first antiferromagnetic layer 15 and less than the blocking temperature of the second antiferromagnetic layer 11; and the second annealing direction is the second direction.

[0106] For example, the above Figure 3 For example, the above Figure 4 For example, the above

[0107] Need to be explained, Figure 4 Only the second direction as the X direction is taken as an example for description, and does not constitute any limitation.

[0108] As Figure 4 indicated, the magnetic field direction used in the second annealing process is along the X direction, the annealing temperature Tb2>T>Tb1, and the second annealing process only changes the pinning direction of the first antiferromagnetic layer 15 to be along the X direction, the magnetic moment direction of the free layer 14 is along the X direction, and the magnetic moment direction of the reference layer 12 remains unchanged and is along the negative direction of the Y direction, so that the magnetic moment direction of the free layer 14 is perpendicular to the magnetic moment direction of the reference layer 12.

[0109] Therefore, through the above first annealing process and second annealing process, the magnetic memory in the initial state can be in the first mode.

[0110] In this way, by performing two-step annealing processes on the magnetic memory in the initial state in advance, the magnetic moment direction of the free layer 14 in the magnetic memory is perpendicular to the magnetic moment direction of the reference layer 12, the magnetic memory is in the first mode, and can be used to detect the surrounding magnetic field.

[0111] In this possible implementation, in the process of placing the magnetic memory in the electronic device for use, when the magnetic memory is in the first mode, the mode of the magnetic memory can be changed by applying a current. Specifically, a current parallel to the second direction can be applied to the first antiferromagnetic layer 15, so that the magnetic moment direction of the free layer 14 changes from the second direction to a direction parallel to the first direction, and the magnetic memory is switched from the first mode to the second mode.

[0112] It should be understood that the second direction parallel to the first direction can include the case that the second direction is the same as or opposite to the first direction, and the embodiments of the present application do not limit the specific manner of parallelism. That is, the direction of the applied current can be the same as or opposite to the first direction, and the embodiments of the present application do not limit this.

[0113] For example, the above Figure 4For example, when the magnetic memory is in the first mode, a write current in the X direction can be applied to the first antiferromagnetic layer 15, and the exchange bias field of the first antiferromagnetic layer 15 and the free layer 14 is flipped to a direction perpendicular to the current, such as the Y direction, so that the magnetic moment of the free layer 14 is also flipped to a direction perpendicular to the current, and at this time, the magnetic moment direction of the free layer 14 and the magnetic moment direction of the reference layer 12 are in a parallel or anti-parallel state.

[0114] Specifically, the write current flips the exchange bias coupling field of the first antiferromagnetic layer 15 and the free layer 14 to a direction perpendicular to the current, so that the magnetic moment direction of the free layer 14 is also flipped to a direction perpendicular to the current.

[0115] For example, as shown in the state of the magnetic memory, Figure 4 Figure 5 A schematic diagram of applying a write current to make the magnetic memory in a high resistance state is provided for the embodiment of the present application.

[0116] It should be noted that Figure 5 Only the first direction is Y direction and the second direction is X direction as an example for description, and it does not constitute any limitation.

[0117] As shown in the state of the magnetic memory, Figure 5 The first direction is Y direction and the second direction is X direction, a write current opposite to the X direction is applied, the magnetic moment direction of the free layer 14 is anti-parallel to the magnetic moment direction of the reference layer 12, and the magnetic memory is in a high resistance state.

[0118] Figure 6 A schematic diagram of applying a write current to make the magnetic memory in a low resistance state is provided for the embodiment of the present application.

[0119] It should be noted that Figure 6 Only the first direction is Y direction and the second direction is X direction as an example for description, and it does not constitute any limitation.

[0120] As shown in the state of the magnetic memory, Figure 6 The first direction is Y direction and the second direction is X direction, a write current opposite to the X direction is applied, the magnetic moment direction of the free layer 14 is anti-parallel to the magnetic moment direction of the reference layer 12, and the magnetic memory is in a high resistance state.

[0121] In combination with Figure 5 and Figure 6 When data storage is performed, the magnetic moment direction of the free layer 14 can be changed by controlling the flow direction of the write current in the X direction to realize the write of the high resistance state and the low resistance state.

[0122] ​Thus, for the magnetic memory in the electronic device in the first mode, the direction of the magnetic moment of the free layer 14 can be changed by applying a current, so that the direction of the magnetic moment of the free layer 14 is parallel to the direction of the magnetic moment of the reference layer 12, so that the magnetic memory is switched to the second mode for data storage, the two modes of sensing and storage can be synchronously integrated in the magnetic memory, and the sensor separately arranged in the electronic device can be removed, thereby saving the occupied space and device cost, and in the process, additional silicon wafer and interconnection structure need not be prepared for the sensor, further reducing the process cost.

[0123] In another possible implementation, the direction of the magnetic moment of the reference layer 12 and the direction of the magnetic moment of the free layer 14 are obtained by sequentially performing annealing treatment and free layer 14 pretreatment on the initial state of the magnetic memory.

[0124] The annealing treatment includes: annealing the initial state of the magnetic memory by using a magnetic field with a first annealing temperature and a first annealing direction, so that the pinning direction of the first antiferromagnetic layer 15 and the pinning direction of the second antiferromagnetic layer 11 are both the first annealing direction; wherein the first annealing temperature is greater than the blocking temperature of the first antiferromagnetic layer 15 and greater than the blocking temperature of the second antiferromagnetic layer 11; and the first annealing direction is the first direction.

[0125] The annealing treatment is similar to the above-mentioned first annealing treatment, and the related description of the first annealing treatment can be referred to, and details are not described herein.

[0126] The free layer 14 pretreatment includes: after the first annealing treatment of the magnetic memory, applying a current parallel to the first direction to the first antiferromagnetic layer 15, so that the direction of the magnetic moment of the free layer 14 changes to the second direction.

[0127] For example, as shown in FIG. 1, Figure 3 For example, as shown in FIG. 1, Figure 3 after the first annealing treatment, the magnetic moments of the free layer 14 and the reference layer 12 are anti-parallel, at this time, a current parallel to the first direction can be applied to the first antiferromagnetic layer 15 of the magnetic memory as shown in FIG. 1, to change the direction of the magnetic moment of the free layer 14, so that the direction of the magnetic moment of the free layer 14 changes to the second direction, that is, the direction of the magnetic moment of the free layer 14 is perpendicular to the direction of the magnetic moment of the reference layer 12, so that the magnetic memory is in the first mode.

[0128] It should be noted that the free layer 14 pretreatment process can be performed when the magnetic memory is not installed in the electronic device for use, or can be performed when the magnetic memory is installed in the electronic device for use, and the embodiments of the present application do not make specific limitations.

[0129] In this way, after one-step annealing, the magnetic moment direction of the free layer 14 and the magnetic moment direction of the reference layer 12 are parallel or anti-parallel, and further, by applying a current to the first antiferromagnetic layer 15, the magnetic moment direction of the free layer 14 and the magnetic moment direction of the reference layer 12 are perpendicular, thus realizing that the magnetic memory is in the first mode by combining annealing and current application.

[0130] Next, the first antiferromagnetic layer 15 is described in different structures.

[0131] In one possible implementation, the first antiferromagnetic layer 15 can have the rectangular structure described in the above embodiment, and in this case, the current direction applied to the first antiferromagnetic layer 15 for mode switching is parallel to the second direction.

[0132] In this way, by applying a current parallel to the second direction to the first antiferromagnetic layer 15, the magnetic moment direction of the free layer 14 changes from the second direction to a direction parallel to the first direction, thus realizing that the magnetic memory is switched from the first mode to the second mode.

[0133] For example, the structure of the first antiferromagnetic layer 15 can also be circular, square, triangular, polygonal, etc., and the current direction applied thereto can be parallel to the second direction, and the embodiment of the present application does not make specific limitations on the structure of the first antiferromagnetic layer 15.

[0134] In this possible implementation, in combination with the above embodiment, the method flow for switching the first mode to the second mode can be referred to Figure 7 , and Figure 7 is a method flow diagram provided by the embodiment of the present application for switching the first mode to the second mode.

[0135] As shown in Figure 7 , the film stack structure is sputtered in sequence to form the magnetic memory in the initial state, and the first-step annealing is performed, wherein the annealing magnetic field is along the first direction, and the annealing temperature T>Tb2>Tb1. Then the second-step annealing is performed, wherein the annealing magnetic field is along the second direction, and the annealing temperature Tb2>T>Tb1. After the second-step annealing, the magnetic memory is in the first mode, and the specific structure can be referred to Figure 4 .

[0136] For the magnetic memory in the first mode, a second-direction write current is applied to the first antiferromagnetic layer 15 to flip the pinning direction of the first antiferromagnetic layer 15 to the first direction, and at this time, the magnetic moment direction of the free layer 14 is parallel or anti-parallel to the magnetic moment direction of the reference layer 12, so that the magnetic memory is in the second mode.

[0137] In another possible implementation, the first antiferromagnetic layer 15 has a cross structure.

[0138] Exemplarily, the corresponding directions in the cross structure are a first direction and a second direction.

[0139] The first direction and the second direction can be perpendicular or have an included angle, for example, 10 degrees, and the embodiments of the present application do not limit this.

[0140] In this possible implementation, when the magnetic memory is in the first mode, a current parallel to the second direction is applied to the first antiferromagnetic layer 15, so that the magnetic moment direction of the free layer 14 changes from the second direction to a direction parallel to the first direction, and the magnetic memory is switched from the first mode to the second mode.

[0141] When the magnetic memory is in the second mode, a current parallel to the first direction is applied to the first antiferromagnetic layer 15, so that the magnetic moment direction of the free layer 14 changes from parallel to the first direction to parallel to the second direction, and the magnetic memory is switched from the second mode to the first mode.

[0142] Exemplarily, the magnetic memory can switch between the first mode and the second mode as shown in Figure 8 . Figure 8 A structure diagram of the magnetic memory provided by the embodiments of the present application for switching between the first mode and the second mode.

[0143] It should be noted that Figure 8 only the first direction is Y direction and the second direction is X direction as an example, and this does not constitute any limitation.

[0144] In this possible implementation, in combination with the above embodiments, the method flow of switching between the first mode and the second mode can be seen from Figure 9 , Figure 9 A method flow diagram of the magnetic memory provided by the embodiments of the present application for switching between the first mode and the second mode.

[0145] As Figure 9 shown, for the magnetic memory in the first mode, a second direction write current is applied to the first antiferromagnetic layer 15, the pinning direction of the first antiferromagnetic layer 15 flips to the first direction, so that the magnetic moment direction of the free layer 14 is parallel or anti-parallel to the magnetic moment direction of the reference layer 12, and the magnetic memory is switched to the second mode.

[0146] For the magnetic memory in the second mode, a first direction write current is applied to the first antiferromagnetic layer 15, the pinning direction of the first antiferromagnetic layer 15 flips to the second direction, so that the magnetic moment direction of the free layer 14 is perpendicular to the magnetic moment direction of the reference layer 12, and the magnetic memory is switched to the first mode.

[0147] In this way, when the first antiferromagnetic layer 15 is a cross structure, the magnetic memory can be switched between the first mode and the second mode. The MRAM in the prior art can only be used for data storage, and the magnetic memory in the application can be switched to the first mode when the magnetic memory in the second mode is idle to detect the magnetic field, which can improve the utilization rate of the magnetic memory, the sensor separately arranged in the electronic device can be removed, thereby saving the occupied space and device cost, and in the process, an additional silicon wafer and interconnection structure do not need to be prepared for the sensor, further reducing the process cost.

[0148] In combination with the above embodiments, the method for detecting the magnetic field by the magnetic memory in the first mode is described.

[0149] When the magnetic memory is in the first mode and a magnetic field parallel to the first direction exists around the magnetic memory, the magnetic moment direction of the free layer 14 deflects by a target angle under the influence of the magnetic field. The target angle is used to determine the size of the magnetic field, and is positively correlated with the size of the magnetic field, and the first direction is parallel to the magnetic moment direction of the reference layer 12.

[0150] It should be noted that when the magnetic moment direction of the free layer 14 deflects by a target angle under the influence of the magnetic field, the larger the magnetic field, the larger the target angle of deflection, and the magnetic moment direction of the free layer 14 deflects by different target angles, and the resistances are different, so the size of the magnetic field can be determined according to the size of the resistance.

[0151] In this way, the magnetic memory can detect the magnetic field parallel to the magnetic moment direction of the reference layer 12, and achieve the purpose of detecting the magnetic field.

[0152] Figure 10 A schematic diagram of the magnetic hysteresis loop of the magnetic memory in different modes provided by the embodiment of the application.

[0153] In the Figure 10 , the sensing mode is the first mode, and the storage mode is the second mode.

[0154] As shown in Figure 10 , the magnetic hysteresis loop corresponding to the magnetic memory in the second mode is relatively “steep”. It indicates that in the storage mode, the material magnetic moment can be stably maintained after the magnetic field acts, which is beneficial to data storage, reading and writing, and the magnetic characteristic makes the magnetic moment direction stable and not easy to be disturbed by the environment stray magnetic field.

[0155] The magnetic hysteresis loop corresponding to the magnetic memory in the sensing mode is relatively “flat”. It indicates that in the sensing mode, the material magnetic moment changes more “continuously and sensitively” with the magnetic field, and a small change in the magnetic field can cause the magnetic moment to change, which can sense the magnetic field, and is suitable for detecting the magnetic field signal as a sensor.

[0156] In combination with the magnetic memory described in the above embodiments, the embodiments of the present application further provide a magnetic storage unit. The magnetic storage unit comprises at least four magnetic memories described in the above embodiments, which are used as bridge arms of a Wheatstone bridge to form a Wheatstone bridge.

[0157] The Wheatstone bridge comprises at least one first magnetic memory in the first mode and at least one second magnetic memory in the second mode.

[0158] It should be noted that at least one magnetic memory is arranged on each bridge arm of the Wheatstone bridge, and the embodiments of the present application do not limit the specific number of magnetic memories included in the magnetic storage unit and the number of magnetic memories on each bridge arm of the Wheatstone bridge.

[0159] It should be noted that the modes of the magnetic memories arranged on the same bridge arm can be the same.

[0160] The manner of detecting the magnetic field by the storage unit comprises: when a magnetic field exists around the Wheatstone bridge, the voltage value of the voltage node of the Wheatstone bridge changes with the size of the magnetic field, and thus the strength of the magnetic field can be determined according to the voltage value of the voltage node of the Wheatstone bridge.

[0161] In this way, by connecting multiple magnetic memories in the form of a Wheatstone bridge, the strength of the magnetic field can be detected based on the voltage value of the voltage node of the Wheatstone bridge.

[0162] Taking the Wheatstone bridge comprising four magnetic memories as an example, the connection manner of the Wheatstone bridge and the manner of detecting the magnetic field are described, which can include the following two possible implementations:

[0163] One possible implementation is that each Wheatstone bridge comprises two first magnetic memories and two second magnetic memories.

[0164] The two first magnetic memories are used as two bridge arms arranged diagonally in the Wheatstone bridge, and the two second magnetic memories are used as two bridge arms arranged diagonally in the Wheatstone bridge.

[0165] It should be noted that the resistance of a single magnetic memory depends on the relative magnetization direction of the magnetic moments of the free layer 14 and the reference layer 12. If the magnetic moment direction of the free layer 14 is parallel to the magnetic moment direction of the reference layer 12, it is in a low resistance state, and if it is antiparallel, it is in a high resistance state. If there is an angle between the magnetic moment direction of the free layer 14 and the magnetic moment direction of the reference layer 12, the resistance is between low resistance and high resistance. If the angle is 90°, the resistance is in the middle.

[0166] The method for detecting a magnetic field by the Wheatstone bridge comprises: when a magnetic field parallel to a first direction exists around the Wheatstone bridge, determining the direction of the magnetic field intensity according to the positive or negative of the voltage value of the voltage node of the Wheatstone bridge, and determining the size of the magnetic field intensity according to the size of the voltage value.

[0167] When a magnetic field parallel to a second direction exists around the Wheatstone bridge, the size of the magnetic field intensity is determined according to the size of the voltage value of the voltage node of the Wheatstone bridge.

[0168] Figure 11 A structural schematic diagram of a magnetic storage unit is provided for the embodiments of the present application. It should be noted that, in order to facilitate the display of the magnetic moment directions of the reference layer 12 and the free layer 14 of each magnetic memory in the magnetic storage unit, Figure 11 only the basic structural units of each magnetic memory and the magnetic moment directions of each film layer in the magnetic memory are shown, and other film layers (such as the soft magnetic layer 19, the decoupling layer 18, the coupling layer 17, the pinned layer 16, etc.) that can be provided in the magnetic memory are omitted. Figure 4

[0169] It should be noted that, in Figure 11 , only the X direction is taken as the first direction and the Y direction is taken as the second direction as an example for illustration, and does not constitute any limitation.

[0170] In Figure 11 , R1, R2, R3, and R4 are all magnetic memories. R1 and R3 are magnetic memories in the second mode, and R2 and R4 are magnetic memories in the first mode.

[0171] In the embodiment, the magnetic moment direction of the reference layer 12 of R1, R2, R3, and R4 is the positive X direction, the magnetic moment direction of the free layer 14 of R1 and R3 is the negative X direction, and the magnetic moment direction of the free layer 14 of R1 and R3 is anti-parallel to the magnetic moment direction of the reference layer 12. The magnetic moment direction of the free layer 14 of R2 and R4 is the negative Y direction, and the magnetic moment direction of the free layer 14 of R2 and R4 is perpendicular to the magnetic moment direction of the reference layer 12.

[0172] V0 is a voltage node, and Vb is a voltage applied to the Wheatstone bridge.

[0173] ​Because a first antiferromagnetic layer 15 is disposed below the free layer 14 of the magnetic memory, the first antiferromagnetic layer 15 can pin the magnetic moment of the free layer 14, making it antimagnetic in a specific direction. For example, R1, the magnetic moment direction of the free layer 14 is pinned in the negative X direction. At this time, a magnetic field with a magnetic field strength less than the pinning strength of the free layer 14 applied along the positive X direction or the negative X direction will not change the magnetic moment direction of the free layer 14. If a magnetic field is applied along the Y direction (i.e., not the pinning direction), the magnetic moment of the free layer 14 will rotate to the direction of the magnetic field. A second antiferromagnetic layer 11 is disposed above the reference layer 12. And because the barrier temperature of the second antiferromagnetic layer 11 is higher than the barrier temperature of the first antiferromagnetic layer 15, the pinning effect of the second antiferromagnetic layer 11 on the reference layer 12 is greater than the pinning effect of the first antiferromagnetic layer 15 on the free layer 14. Therefore, it is difficult for a magnetic field in either the X or Y direction to change the magnetization direction (i.e., the magnetic moment direction) of the reference layer 12. Therefore, the magnetization direction of the reference layer 12 remains unchanged.

[0174] by Figure 11 Using the Wheatstone bridge shown as an example, the method for detecting magnetic fields in magnetic storage cells will be explained.

[0175] One possible implementation is that if a magnetic field in the X direction exists around the magnetic storage cell, the magnetic moment direction of the free layer 14 of R1 and R3 remains unchanged, that is, the angle between the magnetic moment direction of the free layer 14 and the magnetic moment direction of the reference layer 12 remains unchanged, and the resistance of the magnetic storage remains unchanged. However, the free layer 14 of R2 and R4 will rotate in the direction of the magnetic field.

[0176] If the magnetic field around the magnetic storage cell is in the positive X direction, the magnetic moment direction of the free layer 14 of R2 and R4 will rotate to a state parallel to the magnetic moment direction of the reference layer 12, at which point R2 and R4 are in a low-resistance state. V0 is the potential difference between the two endpoints, i.e., the voltage difference between R4 and R3. When the resistance of R2 and R4 decreases, the voltage across R2 and R4 decreases, while the voltage across R1 and R3 increases. Therefore, the potential on the left side of V0 decreases, and the potential on the right side increases, resulting in a negative value for V0. Furthermore, the stronger the magnetic field around the magnetic storage cell, the larger the amplitude of V0. Similarly, if the magnetic field around the magnetic storage cell is in the negative X direction, the potential on the left side of V0 decreases, and the potential on the right side increases, resulting in a positive value for V0.

[0177] Therefore, the direction of the magnetic field around the magnetic storage cell can be determined by the sign of V0, and the magnitude of the magnetic field strength can be determined by the amplitude of V0.

[0178] Another possible implementation is that if there is a magnetic field in the Y direction around the magnetic storage cell, the resistances of R2 and R4 remain unchanged. Since the magnetic moment directions of the reference layer 12 and the free layer 14 are initially antiparallel, R1 and R3 are initially in a high-resistance state.

[0179] If the magnetic field around the magnetic storage unit is in the positive Y direction, the magnetic moment direction of the free layer 14 of R1 and R3 rotates towards the positive Y direction, and the resistance of R1 and R3 changes from the high resistance state to the intermediate state. That is, the resistance of R1 and R3 decreases, the potential on the left of V0 becomes high, and the potential on the right decreases. The greater the magnetic field in the positive Y direction, the greater the angle of the magnetic moment direction of the free layer 14 of R1 and R3 rotating towards the positive Y direction, the more obvious the decrease in the resistance of R1 and R3, and the greater the potential difference between the left and right of V0, and the greater the amplitude of V0.

[0180] If the magnetic field around the magnetic storage unit is in the negative Y direction, the magnetic moment direction of the free layer 14 of R1 and R3 rotates towards the negative Y direction, and the resistance of R1 and R3 changes from the high resistance state to the intermediate state. That is, the resistance of R1 and R3 decreases, the potential on the left of V0 becomes high, and the potential on the right decreases. The greater the magnetic field in the negative Y direction, the greater the angle of the magnetic moment direction of the free layer 14 of R1 and R3 rotating towards the negative Y direction, the more obvious the decrease in the resistance of R1 and R3, and the greater the potential difference between the left and right of V0, and the greater the amplitude of V0.

[0181] Therefore, no matter whether the magnetic field around the magnetic storage unit is in the positive Y direction or the negative Y direction, the potential on the left of V0 becomes high, and the potential on the right decreases, and the greater the magnetic field, the greater the amplitude of V0. At this time, the size of the magnetic field strength can be determined according to the amplitude of V0.

[0182] In this way, by arranging the magnetic storage units in the same mode at the corners of the Wheatstone bridge, the detection of the magnetic field can be realized.

[0183] Another possible implementation is that each Wheatstone bridge includes 3 first magnetic storage units and 1 second magnetic storage unit, or 1 first magnetic storage unit and 3 second magnetic storage units.

[0184] When there is a magnetic field parallel to the first direction around the Wheatstone bridge, the direction of the magnetic field strength is determined according to the positive and negative of the voltage value of the voltage node of the Wheatstone bridge, and the size of the magnetic field strength is determined according to the size of the voltage value.

[0185] When there is a magnetic field parallel to the second direction around the Wheatstone bridge, the size of the magnetic field strength is determined according to the size of the voltage value of the voltage node of the Wheatstone bridge.

[0186] Figure 12 Another structure diagram of a magnetic storage unit provided by the embodiment of the present application.

[0187] In the structure diagram of the magnetic storage unit provided by the embodiment of the present application, Figure 12 In the structure diagram of the magnetic storage unit provided by the embodiment of the present application, R1, R2, R3, and R4 are magnetic storage units. R1, R2, and R4 are magnetic storage units in the first mode, and R3 is a magnetic storage unit in the second mode.

[0188] It should be noted that in the structure diagram of the magnetic storage unit provided by the embodiment of the present application, Figure 12In this example, the X direction is taken as the first direction and the Y direction as the second direction, and this does not constitute any limitation.

[0189] Among them, the magnetic moment direction of the reference layer 12 of R1, R2, R3 and R4 is positive X direction, the magnetic moment direction of the free layer 14 of R3 is negative X direction, the magnetic moment direction of the free layer 14 of R1, R2 and R4 is negative Y direction, and the magnetic moment direction of the free layer 14 of R1, R2 and R4 is perpendicular to the magnetic moment direction of the reference layer 12.

[0190] V0 is the voltage node, and Vb is the voltage applied to the Wheatstone bridge.

[0191] by Figure 12 Using the Wheatstone bridge shown as an example, the method for detecting the magnetic field in a magnetic storage cell will be explained.

[0192] One possible implementation is that if a magnetic field in the X direction exists around the magnetic storage cell, the magnetic moment direction of the free layer 14 of R3 remains unchanged, that is, the angle between the magnetic moment direction of the free layer 14 and the magnetic moment direction of the reference layer 12 remains unchanged, and the resistance of the magnetic storage remains unchanged. However, the magnetic moment directions of the free layers 14 of R1, R2, and R4 will rotate in the direction of the magnetic field.

[0193] If the magnetic field surrounding the magnetic storage cell is in the positive X direction, the magnetic moment direction of the free layer 14 of R1, R2, and R4 will rotate to a state parallel to the magnetic moment direction of the reference layer 12. At this time, R1, R2, and R4 are in a low-resistance state. V0 is the potential difference between the two endpoints, that is, the voltage difference between R4 and R3. At this time, the potential on the left side of V0 remains unchanged, while the potential on the right side increases, and V0 decreases. Moreover, the larger the surrounding magnetic field in the positive X direction, the larger the amplitude of V0.

[0194] If the magnetic field around the magnetic storage cell is in the negative X direction, the resistance of R3 remains unchanged, while the resistances of R1, R2, and R4 all increase. The potential on the left side of V0 remains unchanged, while the potential on the right side decreases, thus increasing V0. The greater the magnetic field in the negative X direction, the greater the amplitude of V0.

[0195] Therefore, the direction of the magnetic field around the magnetic storage cell can be determined by the increase and decrease of V0, and the magnitude of the magnetic field strength can be determined by the amplitude of V0.

[0196] Another possible implementation is that if there is a magnetic field in the Y direction around the magnetic storage cell, the resistances of R1, R2 and R4 remain unchanged, and the magnetic moment direction of the initial reference layer 12 of R3 is antiparallel to the magnetic moment direction of the free layer 14, and is in a high-resistance state.

[0197] If the magnetic field around the magnetic storage unit is in the positive Y direction, the resistances of R1, R2 and R4 remain unchanged, the magnetic moment direction of the free layer 14 of R3 rotates towards the positive Y direction, i.e. the resistance of R3 decreases, the left potential of V0 remains unchanged, the right potential decreases, V0 increases, the greater the magnetic field in the positive Y direction, the greater the angle of the magnetic moment direction of the free layer 14 of R3 rotating towards the positive Y direction, the more obvious the decrease of the resistance of R3, the greater the potential difference between the left and right of V0, and the greater the amplitude of V0.

[0198] If the magnetic field around the magnetic storage unit is in the negative Y direction, the resistances of R1, R2 and R4 remain unchanged, the magnetic moment direction of the free layer 14 of R3 rotates towards the negative Y direction, i.e. the resistance of R3 decreases from the high resistance state to the intermediate state. That is, the resistance of R3 decreases, the left potential of V0 remains unchanged, the right potential decreases, V0 increases, the greater the magnetic field in the negative Y direction, the greater the angle of the magnetic moment direction of the free layer 14 of R3 rotating towards the negative Y direction, the more obvious the decrease of the resistance of R3, the greater the potential difference between the left and right of V0, and the greater the amplitude of V0.

[0199] Therefore, no matter whether the magnetic field around the magnetic storage unit is in the positive Y direction or the negative Y direction, the left potential of V0 remains unchanged, the right potential decreases, and the greater the magnetic field, the greater the amplitude of V0. At this time, the size of the magnetic field can be determined according to the amplitude of V0.

[0200] In this way, by arranging the magnetic storage units in the same mode on three bridge arms of the Wheatstone bridge and arranging the magnetic storage unit in another mode on the other bridge arm, the detection of the magnetic field can be realized.

[0201] In combination with the above-mentioned embodiments, the present application further provides a magnetic storage system, which comprises a conventional storage array, a storage area and a magnetic field detection area.

[0202] The storage area comprises at least one magnetic storage unit in the second mode as described in the above-mentioned embodiments, and i magnetic storage units in the first mode as described in the above-mentioned embodiments.

[0203] i is an integer greater than or equal to 0, and the present application does not limit the specific value of i.

[0204] The magnetic field detection area comprises at least one magnetic storage unit in the first mode as described in the above-mentioned embodiments, and j magnetic storage units in the second mode as described in the above-mentioned embodiments.

[0205] j is an integer greater than or equal to 0, and the present application does not limit the specific value of j.

[0206] The magnetic storage system provided by the embodiments of the present application can protect data. For example, when the magnetic field detected by the magnetic memory in the magnetic field detection area is greater than or equal to the preset magnetic field strength, a current parallel to the second direction is applied to the first antiferromagnetic layer of the i magnetic memories in the first mode in the storage area, so that the magnetic moment direction of the free layer changes from the second direction to a direction parallel to the first direction, and the magnetic memory is switched from the first mode to the second mode; and the data in the conventional storage array is written into the magnetic memory in the second mode in the storage area.

[0207] The preset magnetic field strength can be limited according to the situation of the electronic device, and the embodiments of the present application do not limit this.

[0208] In this way, the magnetic memory in the first mode can detect the magnetic field, and when a large magnetic field is detected, the data in the magnetic storage array is written into the magnetic memory in the second mode in the storage area, which can reduce the damage to the data in the storage array caused by a large magnetic field, and effectively protect the data in the magnetic storage array.

[0209] Figure 13 A flowchart of the storage data transfer provided by the embodiments of the present application is shown.

[0210] As shown in Figure 13 The magnetic storage system includes a magnetic field monitoring module, a global control module, a storage controller, a mode control circuit, a storage area, a conventional storage array, and a data migration channel.

[0211] For example, the conventional storage array is used to store system or user data, and is a spin orbit torque magnetic memory array or a spin transfer torque magnetic memory array without magnetic resistance characteristic magnetic memory array. The embodiments of the present application do not limit the specific type of the conventional storage array.

[0212] The magnetic field monitoring module includes the magnetic field detection area described in the above embodiments, which includes the magnetic memory in the first mode, can be used to collect signals related to the size of the magnetic field, such as the voltage signal described in the above embodiments, and can perform ADC quantization on the collected signals to detect the size of the magnetic field.

[0213] The magnetic field monitoring module can include a threshold comparator, which compares the magnetic field strength of the detected magnetic field with the preset magnetic field strength to determine whether the strength of the detected magnetic field is greater than or equal to the preset magnetic field strength.

[0214] The storage area includes at least one magnetic memory in the second mode and i magnetic memories in the first mode, where i is an integer greater than or equal to 0.

[0215] The storage controller can control the reading and writing of data in the conventional storage array.

[0216] The mode control circuit can control the magnetic memories in the storage area to switch modes, so that the magnetic memories therein are all in the second mode. Specifically, the mode control circuit can control the switching of the mode of the magnetic memories by applying a write current, and specifically, control the write current applied to the first antiferromagnetic layer of the magnetic memories to control the antiferromagnetic memories to switch modes.

[0217] The data migration channel is used to transfer the data stored in the conventional storage array to the magnetic memories in the second mode in the storage area. The data migration channel can be a parallel bus or other forms, and the embodiments of the present application do not limit this.

[0218] In combination with Figure 13 and Figure 14 , the modes of the magnetic storage system are described. Based on Figure 13 , the magnetic field monitoring module continuously or intermittently senses the magnetic field strength of the external magnetic field under the control of the global control module, and sends a magnetic field threshold exceeding interrupt signal to the global control module when it is determined that the magnetic field strength of the external magnetic field is greater than or equal to a preset magnetic field strength. The global control module controls the sending of a switching signal to the mode control circuit based on the magnetic field threshold exceeding interrupt signal. The mode control circuit switches the modes of the magnetic memories in the storage area based on the switching signal, so that the magnetic memories therein are all in the second mode.

[0219] The method of switching the modes of the magnetic memories in the storage area can refer to the method of switching the magnetic memories from the first mode to the second mode described in the above embodiments, which will not be repeated here.

[0220] The global control module also sends a control signal to the storage controller to freeze the storage controller from writing data to the conventional storage array.

[0221] The global control module can also read the data stored in the conventional storage array, that is, read the resistance of each magnetic memory in the conventional storage array. And write the read data to the magnetic memories in the second mode in the storage area through the data migration channel, so as to reduce the damage of the data in the conventional storage array due to the large external magnetic field.

[0222] In the present application, after the data migration is completed, the magnetic field monitoring module continues to monitor the magnetic field, and when it is monitored that the magnetic field strength is less than the preset magnetic field strength and lasts for a period of time, the data recovery mode is started. The data is read from the magnetic memories in the second mode in the storage area and input to the conventional storage array. Further, the magnetic memories in the storage area that have been switched to the second mode can be switched back to the first mode.

[0223] An exemplary Figure 14 timing diagram in a data migration scenario provided by the embodiments of the present application.

[0224] As shown in Figure 14 When the magnetic field strength B is detected to be greater than or equal to the preset magnetic field strength B TH , the data writing to the regular storage array is frozen by the control signal, and the magnetic storage in the storage area is switched to the second mode. The data migration is enabled to start, and the data migration is performed to migrate the data in the regular storage array to the magnetic storage in the second mode in the storage area. When the magnetic field strength B is detected to be less than the preset magnetic field strength B TH , the data recovery is started to write back the data stored in the magnetic storage in the second mode in the storage area to the regular storage array.

[0225] Figure 15 A flowchart of a mode switching method of a magnetic storage system provided by an embodiment of the present application.

[0226] As shown in Figure 15 In the normal operation mode, the read and write of the regular storage array can be performed, and the magnetic field detection module continuously monitors. When B≥B TH is detected, the emergency backup mode is entered. In the emergency backup mode, all write operations of the regular storage array are frozen, the magnetic storage in the first mode in the storage area is switched to the second mode, the high-speed migration is started, the critical data in the regular storage array is migrated to the storage area, and the magnetic storage system enters the strong magnetic field survival mode.

[0227] In the strong magnetic field survival mode, the magnetic field detection module continuously monitors. The magnetic storage in the regular storage array is not pinned by the antiferromagnetic layer, and the magnetic moment direction of the free layer is easily affected by the strong magnetic field, which may cause the data to be damaged. The free layer of the magnetic storage in the storage area is pinned by the exchange bias field of the antiferromagnetic layer, and the data will not be changed by the external magnetic field, which can ensure the safety of the data.

[0228] When B TH is detected, the data recovery mode is entered. In the data recovery mode, the data is read from the magnetic storage in the storage area and written back to the regular storage array. The magnetic storage in the storage area is switched back to the first mode, the write freeze of the regular storage array is removed, and the system returns to normal.

[0229] In conclusion, the magnetic memory in the magnetic storage system can be synchronized to integrate the sensing mode and the storage mode, and can be switched from the sensing mode to the storage mode, so that the sensor separately arranged in the electronic device can be removed, thereby saving the occupied space and device cost, and the additional silicon wafer and interconnection structure for the sensor do not need to be prepared in the process, thereby further reducing the process cost. When the magnetic field strength detected by the magnetic memory in the magnetic field detection area is greater than or equal to the preset magnetic field strength, the current parallel to the second direction is applied to the first antiferromagnetic layer of the magnetic memory in the storage area in the first mode, so that the magnetic memory is switched from the first mode to the second mode, and the data in the conventional storage array is written into the magnetic memory in the storage area in the second mode, so that the data is not damaged under a strong external magnetic field, and the safety of the data is enhanced.

[0230] The division of units in the present application is only a logical functional division, and in actual implementation, another division manner can be used, for example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the units shown or discussed can be indirect coupling or communication connection through some interfaces, devices or units, and can be electrical, mechanical or other forms.

[0231] The units described as separate components can or can not be physically separated, and the components shown as units can or can not be physical units, that is, can be located in one place or can be distributed on a plurality of network units. Part or all of the units can be selected according to actual needs to achieve the purpose of the present embodiment.

[0232] In addition, the functional units in each embodiment of the present application can be integrated in one processing unit, or each unit can be physically present separately, or two or more units can be integrated in one unit.

[0233] If the functions are realized in the form of software function units and sold or used as independent products, the functions can be stored in a computer readable storage medium. Based on this understanding, the technical solutions of the present application or the part of the present application that essentially contributes to the prior art or the part of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes a plurality of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method of each embodiment of the present application. The foregoing storage medium includes a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, and various media that can store program codes.

[0234] Those skilled in the art can understand that all or part of the steps of the above-mentioned method embodiments can be completed by program instruction related hardware. The foregoing program can be stored in a computer readable storage medium. The program executes to perform the steps of the above-mentioned method embodiments; and the foregoing storage medium includes various media capable of storing program codes, such as ROM, RAM, magnetic disk or optical disk.

[0235] Finally, it should be noted that other embodiments of the present application will readily occur to those skilled in the art upon consideration of the specification and practice of the present application disclosed herein. The present application is intended to cover any variations, uses or adaptive changes of the present application following the general principles of the present application and including known or customary technical means in the art not disclosed in the present application, and is not limited to the precise structures described above and shown in the drawings, and various modifications and changes can be made without departing from the scope thereof. The scope of the present application is only limited by the appended claims.

Claims

1. A magnetic memory, comprising: The magnetic memory comprises a first antiferromagnetic layer, a free layer, a barrier layer, a reference layer and a second antiferromagnetic layer stacked in sequence from bottom to top; wherein the magnetic moment direction of the reference layer is a first direction, and the magnetic moment direction of the free layer is a second direction, and the first direction is perpendicular to the second direction; When the magnetic memory is in a first mode, a current parallel to the second direction is applied to the first antiferromagnetic layer, so that the magnetic moment direction of the free layer changes from the second direction to a direction parallel to the first direction, and the magnetic memory is switched from the first mode to a second mode; The first mode is used for detecting a magnetic field around the magnetic memory, and the second mode is used for data storage.

2. The magnetic memory of claim 1 wherein, The first antiferromagnetic layer is a cross structure. When the magnetic memory is in the second mode, a current parallel to the first direction is applied to the first antiferromagnetic layer, so that the magnetic moment direction of the free layer changes from parallel to the first direction to parallel to the second direction, and the magnetic memory is switched from the second mode to the first mode.

3. The magnetic memory of claim 1 wherein, The first antiferromagnetic layer is a rectangular structure, and the direction of the current applied to the first antiferromagnetic layer is parallel to the second direction.

4. The magnetic memory of any of claims 1-3, wherein, When the magnetic memory is in the first mode, and a magnetic field parallel to the first direction exists around the magnetic memory, the magnetic moment direction of the free layer deflects by a target angle under the influence of the magnetic field; the target angle is used to determine the size of the magnetic field, and is positively correlated with the size of the magnetic field.

5. The magnetic memory of any of claims 1-3, wherein, The magnetic moment direction of the reference layer and the magnetic moment direction of the free layer are obtained by sequentially performing a first annealing process and a second annealing process on an initial state of the magnetic memory in advance; The first annealing process comprises annealing the initial state of the magnetic memory by using a magnetic field with a first annealing temperature and a first annealing direction, so that the pinning direction of the first antiferromagnetic layer and the pinning direction of the second antiferromagnetic layer are both the first annealing direction; The first annealing temperature is greater than the blocking temperature of the first antiferromagnetic layer and greater than the blocking temperature of the second antiferromagnetic layer; and the first annealing direction is the first direction; The second annealing process comprises annealing the magnetic memory after the first annealing process by using a magnetic field with a second annealing temperature and a second annealing direction, so that the magnetic moment direction of the free layer changes to the second annealing direction; The second annealing temperature is greater than the blocking temperature of the first antiferromagnetic layer and less than the blocking temperature of the second antiferromagnetic layer; and the second annealing direction is the second direction.

6. The magnetic memory of any one of claims 1-3, wherein, The magnetic moment direction of the reference layer and the magnetic moment direction of the free layer are obtained by sequentially performing an annealing process and a free layer preprocessing on an initial state of the magnetic memory in advance; The annealing process comprises annealing the initial state of the magnetic memory by using a magnetic field with a first annealing temperature and a first annealing direction, so that the pinning direction of the first antiferromagnetic layer and the pinning direction of the second antiferromagnetic layer are both the first annealing direction; The first annealing temperature is greater than a blocking temperature of the first antiferromagnetic layer and greater than a blocking temperature of the second antiferromagnetic layer; and the first annealing direction is the first direction. The pre-treatment of the free layer includes: after the annealing treatment of the magnetic memory, applying a current parallel to the first direction to the first antiferromagnetic layer, so that the magnetic moment direction of the free layer becomes the second direction.

7. A magnetic memory cell, comprising: The Wheatstone bridge is composed of at least four magnetic memories as claimed in any one of claims 1-6 as bridge arms of the Wheatstone bridge. The Wheatstone bridge includes at least one first magnetic memory in the first mode and at least one second magnetic memory in the second mode. When a magnetic field exists around the Wheatstone bridge, the strength of the magnetic field is determined according to the voltage value of the voltage node of the Wheatstone bridge.

8. The magnetic memory cell of claim 7 wherein, Each of the Wheatstone bridges includes two first magnetic memories and two second magnetic memories. The two first magnetic memories are arranged as two diagonal bridge arms of the Wheatstone bridge, and the two second magnetic memories are arranged as two diagonal bridge arms of the Wheatstone bridge. When a magnetic field parallel to the first direction exists around the Wheatstone bridge, the direction of the magnetic field is determined according to the positive and negative of the voltage value of the voltage node of the Wheatstone bridge, and the strength of the magnetic field is determined according to the magnitude of the voltage value. When a magnetic field parallel to the second direction exists around the Wheatstone bridge, the strength of the magnetic field is determined according to the magnitude of the voltage value of the voltage node of the Wheatstone bridge.

9. The magnetic memory cell of claim 7 wherein, Each of the Wheatstone bridges includes three first magnetic memories and one second magnetic memory, or one first magnetic memory and three second magnetic memories. When a magnetic field parallel to the first direction exists around the Wheatstone bridge, the direction of the magnetic field is determined according to the positive and negative of the voltage value of the voltage node of the Wheatstone bridge, and the strength of the magnetic field is determined according to the magnitude of the voltage value. When a magnetic field parallel to the second direction exists around the Wheatstone bridge, the strength of the magnetic field is determined according to the magnitude of the voltage value of the voltage node of the Wheatstone bridge.

10. A magnetic storage system characterized by, The Wheatstone bridge includes a conventional memory array, a memory area, and a magnetic field detection area. The memory area includes at least one magnetic memory as claimed in any one of claims 1-6 in the second mode and i magnetic memories as claimed in any one of claims 1-6 in the first mode; the i is an integer greater than or equal to 0. The magnetic field detection area includes at least one magnetic memory as claimed in any one of claims 1-6 in the first mode and j magnetic memories as claimed in any one of claims 1-6 in the second mode; the j is an integer greater than or equal to 0. When the magnetic field strength detected by the magnetic memory in the magnetic field detection area is greater than or equal to the preset magnetic field strength, an electric current parallel to the second direction is applied to the first antiferromagnetic layer of the i magnetic memories in the storage area in the first mode, so that the magnetic moment direction of the free layer changes from the second direction to a direction parallel to the first direction, and the magnetic memory is switched from the first mode to the second mode; Data in the regular storage array is written into the magnetic memory in the second mode in the storage area.

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