A writing circuit, method and array

Abstract

The present application provides a write circuit, method and array, including a multi-pulse generation module for generating multiple pulse signals; wherein the multiple pulse signals include multiple first pulse signals and second pulse signals that overlap in sequence, and the writing directions of the first pulse signals and the second pulse signals are opposite; the amplitude of the first pulse signal is gradually decreasing, and the amplitude of the second pulse signal between two adjacent first pulse signals is smaller than the amplitude of the two adjacent first pulse signals, and / or the pulse width of the first pulse signal is gradually decreasing, and the pulse width of the second pulse signal between two adjacent first pulse signals is smaller than the pulse width of the two adjacent first pulse signals; a magnetic storage device in an intermediate state is deterministically flipped by multiple pulse signals. The present application can provide a technical solution that can improve the data writing success rate of a magnetic storage device without optimizing the MTJ etching process.

Description

Technical Field

[0001] The present application relates to the technical field of integrated circuit design, and in particular to a writing circuit, method and array. Background Art

[0002] Spin-orbit Torque MRAM (SOT-MRAM) has the advantages of non-volatility, high speed and low power consumption, fast data writing and high device durability, and has become the main candidate for the next generation of memory technology. The basic storage unit structure of SOT-MRAM is to add a heavy metal layer adjacent to the free layer of the MTJ (Magnetic Tunnel Junction) to form a multilayer film structure of "heavy metal / free layer / barrier layer / fixed layer". The flow of current through the heavy metal can generate a spin current, which can flip the magnetization direction of the free layer, thereby realizing data writing.

[0003] Most existing SOT-MTJ data writing methods use one-shot pulse writing. However, due to film layer or process defects of magnetic storage devices, the free layer magnetic moment of MTJ is easily pinned by defects when data is written, thus being in an intermediate state, which in turn leads to unsuccessful data writing of the magnetic storage device.

[0004] At present, MTJ defects are eliminated by using composite continuous free layer, optimizing MTJ etching process, etc. However, it is difficult to avoid the defects caused by MTJ due to the performance level of coating equipment and etching equipment. Summary of the invention

[0005] The present application provides a writing circuit, method and array, which are used to provide a technical solution that can improve the data writing success rate of a magnetic storage device without optimizing the MTJ etching process.

[0006] In a first aspect, the present application provides a write circuit, comprising a multi-pulse generation module for generating a plurality of pulse signals, and providing the plurality of pulse signals to a write end of a magnetic storage device;

[0007] The multiple pulse signals include multiple first pulse signals and second pulse signals that overlap in sequence, and the writing directions of the first pulse signal and the second pulse signal are opposite.

[0008] The amplitude of the latter first pulse signal among the multiple pulse signals is not greater than the amplitude of the former first pulse signal, and the amplitude of the second pulse signal between two adjacent first pulse signals is smaller than the amplitude of the two adjacent first pulse signals, and / or the pulse width of the latter first pulse signal among the multiple pulse signals is not greater than the pulse width of the former first pulse signal, and the pulse width of the second pulse signal between two adjacent first pulse signals is smaller than the pulse width of the two adjacent first pulse signals.

[0009] The magnetic memory in the intermediate state is deterministically flipped through multiple pulse signals.

[0010] In an optional embodiment, the multiple pulse signals include a first pulse sub-signal, a second pulse sub-signal and a third pulse sub-signal, the first pulse sub-signal and the third pulse sub-signal are first pulse signals, and the second pulse sub-signal is a second pulse signal.

[0011] The amplitude of the first pulse sub-signal is greater than the amplitude of the third pulse sub-signal, and / or the pulse width of the first pulse sub-signal is greater than the pulse width of the third pulse sub-signal.

[0012] The amplitude of the second pulse sub-signal is smaller than the amplitudes of the first pulse sub-signal and the third pulse sub-signal, and / or the pulse width of the second pulse sub-signal is smaller than the pulse widths of the first pulse sub-signal and the third pulse sub-signal.

[0013] In an optional embodiment, the falling edge widths of the first pulse sub-signal and the third pulse sub-signal are both greater than their corresponding rising edge widths.

[0014] In a possible implementation, the multi-pulse generation module includes a pulse generation unit.

[0015] The pulse generating unit is used to generate a plurality of first pulse signals and second pulse signals which overlap in sequence, and the amplitude and / or pulse width of the first pulse signal in the plurality of pulse signals decreases in sequence in time.

[0016] In a possible implementation, the multi-pulse generation module further includes an amplitude modulation unit and / or a pulse width modulation unit.

[0017] The amplitude modulation unit is used to adjust the amplitude of the first pulse signal or the second pulse signal.

[0018] The pulse width modulation unit is used to perform pulse width modulation on the first pulse signal or the second pulse signal.

[0019] In a possible implementation manner, a switch module and a magnetic storage device are also included.

[0020] The multi-pulse generating module, the switch module and the writing end of the magnetic storage device are connected in sequence, and the multiple pulse signals are provided to the writing end of the magnetic storage device through the switch module.

[0021] In a possible implementation, the switch module includes at least two switch units, which are respectively used to input the first pulse signal or the second pulse signal to the write ends at both sides of the magnetic storage device after being turned on.

[0022] When a first pulse signal is input to a write end on one side of the magnetic storage device through one of the switch units, a second pulse signal is correspondingly input to a write end on the other side of the magnetic storage device.

[0023] In a possible implementation, the magnetic storage device is a spin-orbit moment magnetic storage device, and the writing of the first pulse signal or the second pulse signal is achieved through two ends of a spin-orbit moment layer in the spin-orbit moment magnetic storage device.

[0024] In a possible implementation, the magnetic memory device is a Nand-type spin-orbit moment magnetic memory, which at least includes a single spin-orbit moment layer and a plurality of magnetic tunnel junctions disposed above the single spin-orbit moment layer.

[0025] The multi-pulse generating module generates a plurality of first pulse signals and a second pulse signal, and inputs the plurality of first pulse signals and the second pulse signals overlapping in sequence through a single spin-orbit moment layer or the top of a Nand-type spin-orbit moment magnetic memory.

[0026] In a second aspect, the present application further provides a write array, comprising: a plurality of write circuits as described in any one of the first aspects arranged in an array; the write array can realize parallel writing of a plurality of magnetic storage devices.

[0027] In a third aspect, the present application also provides a writing method, comprising the following steps:

[0028] Providing a plurality of pulse signals sequentially to the write end of the magnetic storage device; wherein the plurality of pulse signals include a plurality of first pulse signals and second pulse signals overlapping sequentially;

[0029] The amplitude of the latter first pulse signal among the multiple pulse signals is not greater than the amplitude of the former first pulse signal, and the amplitude of the second pulse signal between two adjacent first pulse signals is smaller than the amplitude of the two adjacent first pulse signals, and / or the pulse width of the latter first pulse signal among the multiple pulse signals is not greater than the pulse width of the former first pulse signal, and the pulse width of the second pulse signal between two adjacent first pulse signals is smaller than the pulse width of the two adjacent first pulse signals.

[0030] The magnetic memory in the intermediate state is deterministically flipped through multiple pulse signals.

[0031] In the technical solution provided by the present application, a multi-pulse generating module is used to generate multiple pulse signals and sequentially provide them to the write end of the magnetic storage device. The multiple pulse signals include multiple first pulse signals and second pulse signals that overlap in sequence. It should be understood that the intermediate state is that in the process of magnetic moment reversal of the MTJ free layer, due to the existence of defects, pinning, etc., the magnetic moment is stabilized in a multi-domain state, and in the above-mentioned multiple pulse signals of the present application, a second pulse signal is set between two first pulse signals, and the second pulse signal can consume the multi-domain state of the magnetic storage device, thereby changing the intermediate state of the magnetic storage device, and then providing the first pulse signal to the magnetic storage device, so that the magnetic storage device can be flipped to achieve data writing.

[0032] It should be understood that in actual operation, when the applied pulse amplitude and / or pulse width are too large, it is easy to cause the magnetic storage device to flip back after the successful flip, thereby causing data writing to fail and reducing the write yield. Based on this, in chronological order, the amplitude of the next first pulse signal among the multiple pulse signals is not greater than the amplitude of the previous first pulse signal, and / or the pulse width of the next first pulse signal among the multiple pulse signals is not greater than the pulse width of the previous first pulse signal. Preferably, the amplitude and / or pulse width of the first pulse signal are in a decreasing trend in sequence to ensure that a pulse signal with a larger amplitude and / or pulse width is provided in the initial stage to achieve the flipping of the magnetic storage device. For the magnetic storage device that rebounds due to the excessive pulse amplitude and / or pulse width, the pulse amplitude and / or pulse width are gradually reduced in the subsequent stage to provide a pulse signal with a suitable amplitude and / or pulse width to ensure the flipping of the magnetic storage device, thereby achieving data writing. That is to say, for a magnetic storage device with a relatively small write current, the present application can implement data writing by applying a plurality of first pulse signals with gradually decreasing amplitudes and / or pulse widths.

[0033] The above-mentioned second pulse signal can also be used to offset part of the forward pulse reversed back by the magnetic storage device when the amplitude of the applied pulse is too large. After that, a write current with a smaller amplitude is provided to the magnetic storage device, so that the magnetic storage device can be smoothly flipped, thereby ensuring the writing of data. Therefore, the amplitude of the second pulse signal between two adjacent first pulse signals is smaller than the amplitude of the previous first pulse signal. In order to ensure that the first pulse signal applied subsequently can make the magnetic storage device smoothly flip, the amplitude and / or pulse width of the second pulse signal should be smaller than the amplitude and / or pulse width of the first pulse signal thereafter, so as to avoid the first pulse signal applied thereafter failing to smoothly flip the magnetic storage device due to insufficient energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0035] Figure 1 A schematic diagram of the structure of a writing circuit provided in an embodiment of the present application;

[0036] Figure 2 A circuit diagram of a writing circuit provided in an embodiment of the present application;

[0037] Figure 3 A schematic diagram of a data writing direction in a writing circuit provided in an embodiment of the present application;

[0038] Figure 4 A schematic diagram of a multi-pulse signal provided in an embodiment of the present application;

[0039] Figure 5 A schematic diagram of data writing direction in another writing circuit provided in an embodiment of the present application;

[0040] Figure 6 A schematic diagram of another multi-pulse signal provided in an embodiment of the present application;

[0041] Figure 7 A schematic diagram of another plurality of pulse signals provided in an embodiment of the present application;

[0042] Figure 8 A schematic diagram of the structure of a Nand-type SOT-MRAM provided in an embodiment of the present application;

[0043] Fig. 9 A schematic diagram of a multi-pulse signal applied to a Nand-type SOT-MRAM provided in an embodiment of the present application;

[0044] Fig.10 A graph showing the relationship between the MTJ resistance values ​​when a single pulse is used for writing according to an embodiment of the present application;

[0045] Fig.11 A schematic diagram of another multi-pulse signal applied to a Nand-type SOT-MRAM provided in an embodiment of the present application;

[0046] Fig.12 Another MTJ resistance relationship diagram corresponding to single pulse writing is provided in an embodiment of the present application.

[0047] The above drawings have shown clear embodiments of the present application, which will be described in more detail later. These drawings and text descriptions are not intended to limit the scope of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0048] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application. Instead, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0049] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art to which the present application belongs. The terms used herein in the specification of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. It is understood that the terms "first", "second", etc. used in the present application can be used to describe various information or data in this article, but these elements are not limited by these terms. These terms are only used to distinguish the first information from another information. For example, without departing from the scope of the present application, the first action information can be referred to as the second action information, and similarly, the second action information can be referred to as the first action information. Both the first action information and the second action information are action information, but they are not the same action information.

[0050] Spin-orbit Torque MRAM (SOT-MRAM) has the advantages of non-volatility, high speed and low power consumption, fast data writing and high device durability, and has become the main candidate for the next generation of memory technology. The basic storage unit structure of SOT-MRAM is to add a heavy metal layer adjacent to the free layer of the MTJ (Magnetic Tunnel Junction) to form a multilayer film structure of "heavy metal / free layer / barrier layer / fixed layer". The flow of current through the heavy metal can generate a spin current, which can flip the magnetization direction of the free layer, thereby realizing data writing.

[0051] The existing SOT-MTJ data writing method often adopts a single pulse writing, but the writing current of all devices in the chip array is different. For those memories with smaller writing current, when the applied pulse amplitude is too large, it is easy to cause such devices to flip back after successful flipping, resulting in unsuccessful data writing and reducing the chip writing yield.

[0052] In response to the above problems, the present application provides a technical solution that can continuously generate multiple write pulse signals, wherein the multiple pulse signals include a first pulse signal and a second pulse signal that are overlapped. The second pulse signal is used to prevent the magnetic tunnel junction of the magnetic storage device from being in an intermediate state of writing, thereby providing the first pulse signal to the magnetic storage device to achieve successful data writing.

[0053] The technical solution of the present application and how the technical solution of the present application solves the above-mentioned technical problems are described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0054] First, refer to Figure 1 An embodiment of the present application provides a write circuit, which includes a multi-pulse generating module 10; the multi-pulse generating module 10 is used to generate multiple pulse signals and provide the multiple pulse signals to the write end of the magnetic storage device 20.

[0055] The multi-pulse generating module 10 is used to generate a plurality of write pulse signals. These pulse signals may have different amplitudes and / or pulse widths to optimize the data writing process of the magnetic storage device.

[0056] The multiple pulse signals include multiple first pulse signals and second pulse signals that overlap in sequence, and the writing directions of the first pulse signal and the second pulse signal are opposite.

[0057] The amplitude of the next first pulse signal among the multiple pulse signals is not greater than the amplitude of the previous first pulse signal, and preferably, the amplitude of the first pulse signal shows a gradually decreasing trend. The amplitude of the second pulse signal between two adjacent first pulse signals is smaller than the amplitude of the two adjacent first pulse signals, and / or the amplitude of the next first pulse signal among the multiple pulse signals is not greater than the amplitude of the previous first pulse signal, and preferably, the pulse width of the first pulse signal shows a gradually decreasing trend, and the pulse width of the second pulse signal between two adjacent first pulse signals is smaller than the pulse width of the two adjacent first pulse signals.

[0058] The magnetic memory in the intermediate state is deterministically flipped through multiple pulse signals.

[0059] It should be understood that the intermediate state is when the magnetic moment of the MTJ free layer is switched and the magnetic moment is stabilized in a multi-domain state due to the existence of defects, pinning, etc.

[0060] Using multiple pulse signals to deterministically flip a magnetic storage device in an intermediate state may include: when the magnetic storage device is in an intermediate state after applying a first pulse signal, a second pulse signal after the first pulse signal may be used to consume the multi-domain state of the magnetic storage device, thereby changing the intermediate state of the magnetic storage device, and then providing the first pulse signal to the magnetic storage device to flip the magnetic storage device to achieve data writing.

[0061] It should be understood that in actual operation, when the applied pulse amplitude and / or pulse width is too large, it is easy to cause the magnetic storage device to flip back after a successful flip, resulting in unsuccessful data writing and reduced writing yield.

[0062] Based on this, in chronological order, the amplitude and / or pulse width of the next first pulse signal is not greater than the amplitude and / or pulse width of the previous first pulse signal. Preferably, the amplitude and / or pulse width of the first pulse signal decreases in sequence to ensure that a pulse signal with a larger amplitude and / or pulse width is provided in the initial stage to achieve the flipping of the magnetic storage device. For the flipping rebound caused by the excessive pulse amplitude and / or pulse width, the pulse amplitude and / or pulse width are gradually reduced in the subsequent stage to provide a pulse signal with a suitable amplitude and / or pulse width to ensure the flipping of the magnetic storage device, thereby achieving data writing. In other words, for a magnetic storage device with a relatively small write current, the present application can achieve data writing by applying multiple first pulse signals with gradually decreasing amplitudes and / or pulse widths.

[0063] Moreover, there is a second pulse signal between two first pulse signals among the multiple pulse signals. The second pulse signal is used to offset part of the positive pulse reversed by the magnetic storage device when the applied pulse amplitude is too large. After that, a write current with a smaller amplitude is provided to the magnetic storage device, so that the magnetic storage device can be smoothly flipped, thereby ensuring the writing of data. Therefore, the second pulse signal between two adjacent first pulse signals can be used to offset part of the positive pulse reversed by the magnetic storage device, so its amplitude is smaller than the amplitude of the previous first pulse signal. In order to ensure that the first pulse signal applied subsequently can enable the magnetic storage device to be smoothly flipped, the amplitude and / or pulse width of the second pulse signal should be smaller than the amplitude and / or pulse width of the subsequent first pulse signal, so as to avoid the first pulse signal applied subsequently affecting the smooth flipping of the magnetic storage device due to insufficient energy.

[0064] Based on the above description, the present application can realize data writing of the magnetic storage device without optimizing the MTJ etching process. Therefore, the present application can improve the success rate of data writing of the magnetic storage device.

[0065] In some examples, the writing circuit may further include a switch module and a magnetic storage device;

[0066] The multi-pulse generating module, the switch module and the writing end of the magnetic storage device are connected in sequence, and the multiple pulse signals are provided to the writing end of the magnetic storage device through the switch module.

[0067] The multi-pulse generating module is connected to the writing end of the magnetic storage device.

[0068] The magnetic storage device can be any type of magnetic storage device, such as magnetoresistive random access memory (MRAM), spin transfer torque random access memory (STT-RAM) or spin orbit torque magnetic memory (SOT-MRAM), and the embodiments of the present application do not specifically limit this. It should be understood that the write end of the magnetic storage device 20 is used to receive a write signal to change its storage state.

[0069] The switch module is used to control the transmission of the write signal. The switch module may include one or more switch elements, such as transistors, relays, etc. The input end of the switch module is connected to the output end of the multi-pulse generation module 10, and the output end is connected to the write end of the magnetic storage device.

[0070] The above content describes the overall structure and principle of the write circuit for the magnetic memory device provided in the embodiment of the present application, wherein the magnetic memory device may be MRAM, STT-RAM or SOT-MRAM. The following content focuses on describing the structure of SOT-MRAM.

[0071] Optionally, the SOT-MRAM may include a SOT layer, a free layer, a barrier layer, a reference layer, a pinned layer and a top electrode layer from bottom to top.

[0072] In one example, an insertion layer can be set between two adjacent layers to improve the performance of SOT-MRAM. For example, a metal Hf (hafnium) layer or a non-metal MgO (magnesium oxide) layer can be set between the SOT (Spin-orbit Torque) layer and the free layer to regulate the magnetic anisotropy of the free layer and the interface Rashba effect, thereby reducing the write current power consumption. Among them, the Rashba effect is a spin-orbit coupling phenomenon caused by the breaking of structural inversion symmetry. Specifically, when electrons move in a material with an interface or surface, the inversion symmetry of the material is destroyed due to the existence of the interface or surface, resulting in coupling between the spin and momentum of the electron, which will cause the splitting of the electron band structure and the spin splitting.

[0073] The SOT layer material can be a heavy metal material, such as any one of Pt, Pd, Hf, Au, AuPt, PtHf, PtCr, PtMn, IrMn, Ir, FeMn, NiMn, Ta, W, WO, WN, W(O,N), TaN, TaB, WTaB, or a topological insulator, such as Bi x Se 1-x ,Bi x Sb 1-x ,(Bi,Sb) 2 Te 3 Any of them, or two-dimensional materials such as MoS 2 、WTe 2 Etc., or it may be a multilayer film structure, comprising two or more of the above materials.

[0074] It should be understood that when current flows through the SOT layer, a spin current is generated, which can change the direction of the magnetic moment of the free layer above, thereby enabling the MTJ to switch between high and low resistance states, thereby enabling data writing.

[0075] The free layer and the reference layer are generally ferromagnetic materials, and can also be ferrimagnetic or antiferromagnetic materials. Ferromagnetic materials can be one or more combinations of Co, Fe, Ni, CoFe, CoFeB, FeB, CoB, NiFe, etc.; ferrimagnetic materials can be one or more combinations of GdFeCo, CdFe, CoTb, etc.; antiferromagnetic materials can be one or more combinations of IrMn, PtMn, FeMn, PdMn, Mn3Sn, Mn3Pt, Mn3Ir, Mn3Ge, etc. The free layer and the reference layer can also be composite layers, for example, composed of two magnetic layers, and a layer of metal such as Ru, W, Mo, Ta, Ir, etc. is interspersed in the middle, so that the upper and lower magnetic layers form ferromagnetic (magnetic moments are parallel to each other) or antiferromagnetic coupling (magnetic moments are antiparallel).

[0076] The barrier layer can be an insulator, such as oxides such as MgO, Al2O3, etc.

[0077] The pinned layer may be an antiferromagnetic material, such as IrMn, PtMn, FeMn, PdMn, or one or more combinations thereof.

[0078] The above content describes the specific structure of SOT-MRAM and the data writing principle. The following describes the switch modules of the above writing circuit respectively.

[0079] Optionally, the switch module includes at least two switch units, which are used to input the first pulse signal or the second pulse signal to the write ends on both sides of the magnetic storage device after being turned on.

[0080] When a first pulse signal is input to a write end on one side of the magnetic storage device through one of the switch units, a second pulse signal is correspondingly input to a write end on the other side of the magnetic storage device.

[0081] In a specific example, the switch module includes a first switch unit and a second switch unit, and the write end of the magnetic storage device includes a first write end and a second write end.

[0082] The multi-pulse generating module is connected to the first writing end through the first switching unit, and is connected to the second writing end through the second switching unit.

[0083] Based on this, the first switch unit can be used to control the transmission of the first pulse signal, and the second switch unit can be used to control the transmission of the second pulse signal. The first switch unit and the second switch unit can be implemented by a switch tube or other electronic switch, and the embodiment of the present application does not make any special limitation on this.

[0084] It should be understood that the above-mentioned first switch unit can also be used to control the transmission of the second pulse signal, and the second switch unit can also be used to control the transmission of the first pulse signal. The embodiment of the present application does not make any special limitation on this.

[0085] When the current output signal is a first pulse signal, the multi-pulse generating module is used to provide the positive pulse signal to the first write end through the first switch module to realize data writing to the storage device magnetic storage device. When the current output signal is a second pulse signal, the multi-pulse generating module is used to provide a negative pulse signal to the second write end through the second switch module to change the intermediate state of the storage device magnetic storage device.

[0086] In an example, the first switch module may include a first switch tube and a second switch tube.

[0087] Among them, the first end of the first switch tube is connected to the multi-pulse generating module, the control end is connected to the external control signal end, the second end is connected to the first end and the first writing end of the second switch tube, the control end of the second switch tube is connected to the external control signal end, and the second end is connected to the first writing end and the ground end.

[0088] The current output signal of the multi-pulse generation module is the first pulse signal, and the external control signal terminal generates a corresponding control signal, which is used to control the first switch tube to turn on and the second switch tube to turn off. At this time, the first pulse signal is applied to the first write terminal through the first switch tube to realize data writing.

[0089] In another example, the second switch module includes a third switch tube and a fourth switch tube.

[0090] Among them, the first end of the third switch tube is connected to the multi-pulse generating module, the second end is connected to the external control signal end, the third end is connected to the first end of the fourth switch tube and the second writing end, the control end of the fourth switch tube is connected to the external control signal end, and the third end is connected to the second writing end and the ground end.

[0091] The current output signal of the multi-pulse generating module is the second pulse signal, and the external control signal terminal generates a corresponding control signal, which is used to control the third switch tube to be turned on and the fourth switch tube to be turned off. At this time, the second pulse signal is applied to the second writing terminal through the third switch tube to change the intermediate state of the magnetic storage device.

[0092] Optional, see Figure 2 The first switch unit 201 includes a first switch tube N1 and a second switch tube P1, and the second switch unit 202 includes a third switch tube P2 and a fourth switch tube N2. The control ends of the first switch tube N1, the second switch tube P1, the third switch tube P2 and the fourth switch tube N2 are all connected to the external control signal end, and the external control signal end is used to provide a control signal Vg.

[0093] The current output signal of the multi-pulse generating module is the first pulse signal, the external control signal terminal generates a high-level control signal, the first switch tube and the fourth switch tube are turned on, the positive pulse is applied to the magnetic storage device through the first switch tube, and the generated current flows from the first switch tube, the magnetic storage device, and the fourth switch tube to the ground terminal to complete the data writing.

[0094] That is to say, when the current output signal of the multi-pulse generating module is the first pulse signal, the first switch tube, the magnetic storage device, the fourth switch tube and the ground terminal form a first loop to implement data writing to the magnetic storage device.

[0095] The current output signal of the multi-pulse generating module is the second pulse signal, the external control signal terminal generates a low-level control signal, the second switch tube and the third switch tube are turned on, and the negative pulse is applied to the magnetic storage device through the third switch tube. The direction of the generated current flows from the third switch tube, the magnetic storage device, and the second switch tube to the ground terminal, which is used to change the intermediate state of the magnetic storage device.

[0096] That is, when the current output signal of the multi-pulse generating module is the second pulse signal, the third switch tube, the magnetic storage device, the second switch tube and the ground terminal form a second loop to change the intermediate state of the magnetic storage device.

[0097] The above content is used to describe the structure and function of the switch module, and the following part is used to describe the multi-pulse generation module.

[0098] Optionally, the multi-pulse generation module may include a pulse generation unit, which is used to generate a plurality of first pulse signals and second pulse signals that overlap in sequence, and the amplitude of the first pulse signal in the plurality of pulse signals decreases in sequence in time.

[0099] According to the above description, the amplitude of the first pulse signal among the multiple pulse signals decreases successively, which can ensure that a pulse signal with a larger amplitude is provided in the initial stage to realize the flipping of the magnetic storage device, and for the flipping rebound caused by the excessive pulse amplitude, the pulse amplitude is gradually reduced in the subsequent stage to provide a pulse signal with a suitable amplitude to ensure the flipping of the magnetic storage device to realize data writing. In other words, for a magnetic storage device with a relatively small write current, the embodiment of the present application realizes data writing by applying multiple first pulse signals with gradually decreasing amplitudes.

[0100] It should be understood that, corresponding to different amplitude and pulse width requirements, the multi-pulse generation module in the embodiment of the present application may also include a pulse width modulation unit and an amplitude modulation unit.

[0101] The pulse width modulation unit is used to perform pulse width modulation on the first pulse signal or the second pulse signal, so that the pulse width of the pulse signal output by the multi-pulse generating module can be adjusted according to needs to adapt to different needs, thereby optimizing the writing process of the magnetic storage device and ensuring the stability and reliability of the magnetic storage device under different operating conditions.

[0102] The amplitude modulation unit is used to adjust the amplitude of the first pulse signal or the second pulse signal. By adjusting the amplitude of the pulse signal, the energy of the pulse signal applied to the magnetic storage device can be controlled to avoid the flip rebound problem caused by excessive pulse amplitude, thereby improving the success rate of data writing.

[0103] In a specific embodiment, referring to Figure 3 and Figure 4 , assuming that the writing direction of the magnetic storage device is Figure 3 In the direction indicated by the arrow (from left to right), the multiple first pulse signals and second pulse signals overlapping in sequence include a first pulse sub-signal S1, a second pulse sub-signal S2 and a third pulse sub-signal S3. The first pulse sub-signal S1 and the third pulse sub-signal S3 are first pulse signals, and the second pulse sub-signal S2 is a second pulse signal.

[0104] Among them, the pulse width d1 and / or amplitude of the first pulse sub-signal S1 is greater than the pulse width d3 and / or amplitude of the second pulse sub-signal S3, and / or the pulse width d1 and amplitude of the first pulse sub-signal S1 are greater than the pulse width d3 and amplitude of the third pulse sub-signal S3.

[0105] In a specific embodiment, referring to Figure 5 and Figure 6 , assuming that the writing direction of the magnetic storage device is Figure 5 In the direction indicated by the arrow (from right to left), the multiple sequentially overlapping first pulse signals and second pulse signals include a first pulse sub-signal S1, a second pulse sub-signal S2 and a third pulse sub-signal S3. The first pulse sub-signal S1 and the third pulse sub-signal S3 are first pulse signals, and the second pulse sub-signal S2 is a second pulse signal.

[0106] Among them, the pulse width d1 and / or amplitude of the first pulse sub-signal S1 is greater than the pulse width d3 and / or amplitude of the second pulse sub-signal S3, and / or the pulse width d1 and amplitude of the first pulse sub-signal S1 are greater than the pulse width d3 and amplitude of the third pulse sub-signal S3.

[0107] According to the above, the first pulse sub-signal S1 is used to provide a pulse signal with greater energy to write data to a magnetic storage device with a larger write current. For a magnetic storage device with a smaller write current, it may cause the magnetic storage device to flip back after a successful flip. At this time, a second pulse sub-signal S2 with a reduced amplitude and / or pulse width is input to the magnetic storage device to offset part of the first positive pulse reversed by the magnetic storage. After that, a third pulse sub-signal S3 with less energy is applied to the magnetic storage device to enable the magnetic storage device to flip smoothly, thereby ensuring the writing of data.

[0108] It should be understood that the multiple first pulse signals and second pulse signals that overlap in sequence in the embodiment of the present application may include not only the above three pulse signals, but also more pulse signals.

[0109] Optionally, the multiple first pulse signals and second pulse signals that overlap in sequence include 2N+1 pulse signals. It should be understood that by setting more pulse signals, the amplitude of the first pulse signal can be gradually reduced, thereby ensuring that the magnetic storage device is smoothly flipped and data is written.

[0110] In another embodiment, referring to Figure 7 The above-mentioned first pulse sub-signal S1, second pulse sub-signal S2 and third pulse sub-signal S3 can be pulse signals with rising edges and falling edges.

[0111] It should be understood that the pulse signal with rising and falling edges can include instantaneous pulse signals with multiple pulse widths, so that accurate data writing control can be provided to ensure data writing. Among them, the second pulse signal S2 is used to offset the part of the first positive pulse S1 reversed back by the magnetic storage device and consume the multi-domain state of the magnetic storage device to change the intermediate state of the magnetic storage device. After that, the third pulse signal S3 with a smaller amplitude is provided to the magnetic storage device, so that the magnetic storage device can be smoothly flipped and data writing can be achieved.

[0112] It should be further understood that, in this embodiment, since the first pulse sub-signal S1, the second pulse sub-signal S2 and the third pulse sub-signal S3 are pulse signals with rising edges and falling edges, each pulse signal includes instantaneous pulse signals with multiple pulse widths. Therefore, the embodiment of the present application does not need to set more pulse signals, which saves data writing time and improves the writing efficiency of the device.

[0113] Preferably, the falling edge widths of the first pulse sub-signal S1 and the third pulse sub-signal S3 are greater than the corresponding rising edge widths. It should be further understood that the falling edges of the first pulse sub-signal S1 and the third pulse sub-signal S3 are used to provide multiple instantaneous pulse signals of different pulse widths and / or amplitudes when writing data to the magnetic storage device. If the width of the falling edge is small, it will cause multiple instantaneous pulse signals to change faster, thereby increasing the difficulty of data writing and may cause data writing to fail. Therefore, it is necessary to set the falling edge widths of the first pulse sub-signal S1 and the third pulse sub-signal S3 to be larger to improve the success rate of data writing.

[0114] In some examples, the magnetic memory device is a spin-orbit torque magnetic memory, and the writing of the first pulse signal or the second pulse signal is achieved through two ends of a spin-orbit moment layer in the spin-orbit torque magnetic memory.

[0115] As a specific example, the magnetic storage device in the embodiment of the present application is a spin-orbit torque magnetic storage device, the above-mentioned first write end is the first end of the spin-orbit moment layer (SOT layer) of the spin-orbit torque magnetic storage device, and the second write end is the second end of the spin-orbit moment layer of the spin-orbit torque magnetic storage device.

[0116] Based on this, when the above-mentioned first pulse signal is applied to the SOT layer, the SOT layer generates a spin current, which can change the direction of the magnetic moment of the free layer above the SOT layer, so that the MTJ can switch between high and low resistance states, thereby enabling data writing. When the above-mentioned second pulse signal is applied to the SOT layer, it can not only offset the part of the forward pulse reversed by the previous first pulse signal applied to the SOT layer, but also consume the multi-domain state of the SOT layer to change the intermediate state of the magnetic storage device, thereby ensuring that the first pulse signal applied to the SOT layer later can change the direction of the magnetic moment of the free layer above the SOT layer to achieve data writing.

[0117] In some other examples, the magnetic memory device is a Nand-type spin-orbit torque magnetic memory, which includes at least a single spin-orbit moment layer and a plurality of magnetic tunnel junctions disposed above the single spin-orbit moment layer.

[0118] The multi-pulse generating module generates a plurality of first pulse signals and a second pulse signal, and inputs the plurality of first pulse signals and the second pulse signals overlapping in sequence through a single spin-orbit moment layer or the top of a Nand-type spin-orbit moment magnetic memory.

[0119] The amplitude of the first pulse signal shows a gradually decreasing trend, and the amplitude of the second pulse signal between two adjacent first pulse signals is smaller than the amplitude of the two adjacent first pulse signals, and / or the pulse width of the first pulse signal shows a gradually decreasing trend, and the pulse width of the second pulse signal between two adjacent first pulse signals is smaller than the pulse width of the two adjacent first pulse signals.

[0120] Optionally, the magnetic storage device in the embodiment of the present application is a Nand-type spin-orbit torque magnetic storage device including a first write end and a second write end, wherein the first write end is one end of the spin-orbit moment layer in the Nand-type spin-orbit torque magnetic storage device and the top of the magnetic tunnel junction.

[0121] The second writing end is one end of the spin-orbit moment layer of the Nand-type spin-orbit moment magnetic memory or the top of the magnetic tunnel junction.

[0122] Reference Figure 8 Nand-type SOT-MRAM is a SOT layer shared by multiple MTJs. The gating of MTJ is achieved by applying current to the corresponding MTJ. For example, to select the second MTJ, current can be applied to the top electrode layer of the second MTJ for selection.

[0123] For Nand-type SOT-MRAM, since applying a pulse signal to the SOT layer alone is not enough to flip the magnetic moment of the MTJ free layer, it is necessary to apply a pulse signal to the top electrode layer of the corresponding MTJ to achieve data writing of the selected MTJ. By controlling the timing of the pulse signal applied to the SOT and the pulse signal applied to the MTJ, polymorphic storage of the selected MTJ can be achieved.

[0124] The following section describes the data writing process of Nand-type SOT-MRAM by applying different pulse sequences. Fig. 9 , the pulse signal applied to the SOT layer overlaps with the pulse signal applied to the MTJ top electrode layer, and the width of the overlapping part is ≥ 0. At this time, data writing can be achieved, but the ability to eliminate the intermediate state is poor. Fig.10 , when the pulse signal applied to the Nand-type SOT-MRAM is Fig. 9 When the first pulse signal sequence in the MTJ is used and the MTJ has certain defects or pinning, it is easy to stabilize it in the intermediate state.

[0125] Reference Fig.11 , the pulse signal applied to the SOT layer in the first pulse signal sequence and the pulse signal applied to the MTJ top electrode layer do not overlap. This pulse signal is similar to the form of the above-mentioned multi-pulse signal, which can effectively eliminate the intermediate state. Fig.12 ,based on Fig.11 The second pulse signal sequence in the embodiment can easily realize stable data writing. The initial position indicates the position of the initial pulse signal of the second pulse signal sequence.

[0126] Therefore, in combination with the first pulse signal sequence and the second pulse signal sequence, the embodiment of the present application can realize polymorphic storage of the MTJ, improve the storage capacity of the MTJ, and thus improve the storage density of the Nand-type SOT-MRAM chip.

[0127] Optionally, when writing data to the Nand-type SOT-MRAM, a first pulse signal can be applied to the SOT layer through the first end of the SOT layer, and then a second pulse signal is applied to the SOT layer, and finally the first pulse signal is applied to the top electrode layer of the MTJ to achieve data writing to the Nand-type SOT-MRAM.

[0128] Optionally, when writing data to the Nand-type SOT-MRAM, a first pulse signal can be applied to the SOT layer through the first end of the SOT layer, and then a second pulse signal is applied to the top electrode layer of the MTJ, and finally the first pulse signal is applied to the top electrode layer of the MTJ to complete the data writing to the Nand-type SOT-MRAM.

[0129] Based on this, the embodiment of the present application adopts a multi-pulse writing method to effectively reduce the storage intermediate state of the Nand-type SOT-MRAM, thereby improving the storage yield of the Nand-type SOT-MRAM chip. In addition, combined with multi-pulse writing, polymorphic storage can be achieved to improve storage density. Compared with the existing polymorphic storage method, there is no need to introduce complex processes or multiple devices.

[0130] In a second aspect, the present application further provides a write array, comprising a plurality of write circuits according to any one of the first aspects arranged in an array.

[0131] The write array can realize parallel writing of multiple magnetic storage devices.

[0132] It should be understood that since the read-write array includes the above-mentioned write circuit, the read-write array is Figure 1-Figure 12 The beneficial effects of the writing circuit provided in the illustrated embodiment are the same and will not be described in detail here.

[0133] In a third aspect, the embodiment of the present application further provides a writing method, comprising the following steps:

[0134] Providing a plurality of pulse signals sequentially to the write end of the magnetic storage device; wherein the plurality of pulse signals include a plurality of first pulse signals and second pulse signals that overlap sequentially;

[0135] The amplitude of the first pulse signal shows a gradually decreasing trend, and the amplitude of the second pulse signal between two adjacent first pulse signals is smaller than the amplitude of two adjacent first pulse signals, and / or the pulse width of the first pulse signal shows a gradually decreasing trend, and the pulse width of the second pulse signal between two adjacent first pulse signals is smaller than the pulse width of two adjacent first pulse signals;

[0136] The magnetic memory in the intermediate state is deterministically switched by the multiple pulse signals.

[0137] The writing method provided by the present application provides multiple pulse signals to the writing end of the magnetic storage device. The multiple pulse signals include multiple first pulse signals and second pulse signals that overlap in sequence. It should be understood that the intermediate state is that in the process of magnetic moment reversal of the MTJ free layer, due to the existence of defects, pinning, etc., the magnetic moment is stabilized in a multi-domain state, and there is a second pulse signal between the two first pulse signals in the above-mentioned multiple pulse signals. The second pulse signal can consume the multi-domain state of the magnetic storage device, thereby changing the intermediate state of the magnetic storage device. After that, the first pulse signal is provided to the magnetic storage device, so that the magnetic storage device can be flipped to achieve data writing.

[0138] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A writing circuit, characterized in that: A multi-pulse generating module is included for generating a plurality of pulse signals, and providing the plurality of pulse signals to a writing end of a magnetic storage device; The plurality of pulse signals include a plurality of first pulse signals and second pulse signals that overlap in sequence, and the first pulse signal and the second pulse signal have opposite writing directions; the multi-domain state of the magnetic storage device is consumed by the second pulse signal, thereby changing the intermediate state of the magnetic storage device; The amplitude of the latter first pulse signal among the multiple pulse signals is not greater than the amplitude of the former first pulse signal, and the amplitude of the second pulse signal between two adjacent first pulse signals is smaller than the amplitude of two adjacent first pulse signals, and / or the pulse width of the latter first pulse signal among the multiple pulse signals is not greater than the pulse width of the former first pulse signal, and the pulse width of the second pulse signal between two adjacent first pulse signals is smaller than the pulse width of two adjacent first pulse signals; The plurality of pulse signals are used to deterministically flip the magnetic memory in the intermediate state; when the magnetic memory device is a spin-orbit moment memory, the plurality of pulse signals can be provided to the top of the magnetic tunnel junction and the spin-orbit moment layer.

2. The writing circuit according to claim 1, characterized in that: The multiple pulse signals include a first pulse sub-signal, a second pulse sub-signal and a third pulse sub-signal, the first pulse sub-signal and the third pulse sub-signal are the first pulse signal, and the second pulse sub-signal is the second pulse signal; The amplitude of the first pulse sub-signal is greater than the amplitude of the third pulse sub-signal, and / or the pulse width of the first pulse sub-signal is greater than the pulse width of the third pulse sub-signal; The amplitude of the second pulse sub-signal is smaller than the amplitudes of the first pulse sub-signal and the third pulse sub-signal, and / or the pulse width of the second pulse sub-signal is smaller than the pulse widths of the first pulse sub-signal and the third pulse sub-signal.

3. The writing circuit according to claim 2, characterized in that: The falling edge widths of the first pulse sub-signal and the third pulse sub-signal are both greater than their corresponding rising edge widths.

4. The writing circuit according to claim 1, characterized in that: The multi-pulse generation module includes a pulse generation unit; The pulse generating unit is used to generate a plurality of first pulse signals and second pulse signals which overlap in sequence, and the amplitude and / or pulse width of the first pulse signal in the plurality of pulse signals decreases in sequence in time.

5. The writing circuit according to claim 4, characterized in that: The multi-pulse generation module further includes an amplitude modulation unit and / or a pulse width modulation unit; The amplitude modulation unit is used to adjust the amplitude of the first pulse signal or the second pulse signal; The pulse width modulation unit is used to perform pulse width modulation on the first pulse signal or the second pulse signal.

6. The writing circuit according to claim 1, characterized in that: Also included are a switch module and a magnetic storage device; The multi-pulse generating module, the switch module and the write end of the magnetic storage device are connected in sequence, and the multiple pulse signals are provided to the write end of the magnetic storage device through the switch module.

7. The writing circuit according to claim 6, characterized in that: The switch module comprises at least two switch units, which are respectively used to input a first pulse signal or a second pulse signal to the write ends on both sides of the magnetic storage device after being turned on; When a first pulse signal is input to a write end on one side of the magnetic storage device through one of the switch units, a second pulse signal is correspondingly input to a write end on the other side of the magnetic storage device.

8. The writing circuit according to claim 6, characterized in that: The magnetic storage device is a spin-orbit moment magnetic storage device, and the writing of the first pulse signal or the second pulse signal is realized through two ends of a spin-orbit moment layer in the spin-orbit moment magnetic storage device.

9. The writing circuit according to claim 6, characterized in that: The magnetic memory device is a Nand-type spin-orbit moment magnetic memory, which at least includes a single spin-orbit moment layer and a plurality of magnetic tunnel junctions arranged above the single spin-orbit moment layer; The multi-pulse generating module generates a plurality of first pulse signals and a second pulse signal, and inputs the plurality of first pulse signals and the second pulse signals overlapping in sequence through the top of the single spin-orbit moment layer or the Nand-type spin-orbit moment magnetic memory.

10. A write array, characterized in that: A plurality of write circuits according to any one of claims 1 to 9 arranged in an array; The write array can realize parallel writing of multiple magnetic storage devices.

11. A writing method, characterized in that: The following steps are involved: Providing a plurality of pulse signals sequentially to the write end of the magnetic storage device; wherein the plurality of pulse signals include a plurality of first pulse signals and second pulse signals that overlap sequentially; the second pulse signal is used to consume the multi-domain state of the magnetic storage device, thereby changing the intermediate state of the magnetic storage device; The amplitude of the latter first pulse signal among the multiple pulse signals is not greater than the amplitude of the former first pulse signal, and the amplitude of the second pulse signal between two adjacent first pulse signals is smaller than the amplitude of two adjacent first pulse signals, and / or the pulse width of the latter first pulse signal among the multiple pulse signals is not greater than the pulse width of the former first pulse signal, and the pulse width of the second pulse signal between two adjacent first pulse signals is smaller than the pulse width of two adjacent first pulse signals; The plurality of pulse signals are used to deterministically flip the magnetic memory in the intermediate state; when the magnetic memory device is a spin-orbit moment memory, the plurality of pulse signals can be provided to the top of the magnetic tunnel junction and the spin-orbit moment layer.

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