WO2022077499A1 - 一种存储器及电子设备 - Google Patents

一种存储器及电子设备 Download PDF

Info

Publication number
WO2022077499A1
WO2022077499A1 PCT/CN2020/121680 CN2020121680W WO2022077499A1 WO 2022077499 A1 WO2022077499 A1 WO 2022077499A1 CN 2020121680 W CN2020121680 W CN 2020121680W WO 2022077499 A1 WO2022077499 A1 WO 2022077499A1
Authority
WO
WIPO (PCT)
Prior art keywords
layer
free layer
electrode
mtj
memory
Prior art date
Application number
PCT/CN2020/121680
Other languages
English (en)
French (fr)
Inventor
秦青
周雪
刘熹
Original Assignee
华为技术有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 华为技术有限公司 filed Critical 华为技术有限公司
Priority to CN202080105271.7A priority Critical patent/CN116250040B/zh
Priority to PCT/CN2020/121680 priority patent/WO2022077499A1/zh
Publication of WO2022077499A1 publication Critical patent/WO2022077499A1/zh

Links

Images

Classifications

    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11C—STATIC STORES
    • G11C11/00—Digital stores characterised by the use of particular electric or magnetic storage elements; Storage elements therefor
    • G11C11/02—Digital stores characterised by the use of particular electric or magnetic storage elements; Storage elements therefor using magnetic elements

Definitions

  • the present application relates to the field of memory technologies, and in particular, to a memory and an electronic device.
  • Magnetic random access memory is a new type of non-volatile memory.
  • spin transfer torque magnetic random access memory is compatible with COMS (complementary metal-oxide-semiconductor, complementary metal-oxide-semiconductor) due to its high speed, low power consumption
  • COMS complementary metal-oxide-semiconductor, complementary metal-oxide-semiconductor
  • the read-write function of the spin-distance magnetic random access memory is realized by the storage unit of the spin-distance magnetic random access memory.
  • the main structure of a memory cell consists of a magnetic tunneling junction (MTJ) and a transistor.
  • the structure of MTJ is mainly composed of a free layer for storing information, a tunneling layer, a reference layer with a fixed magnetization direction, and a pinned layer stacked in sequence. Among them, the magnetization direction of the reference layer is pinned in a certain direction and the magnetization direction remains unchanged, the magnetization direction of the free layer can be changed, and the current flows through the MTJ from different directions (the current flows from the pinned layer to the free layer or the current flows from the free layer to the free layer.
  • the magnetization direction of the free layer will change accordingly.
  • the memory cell When the magnetization direction of the free layer is parallel to the magnetization direction of the reference layer, the memory cell exhibits low resistance, which can be stored as "0";
  • the magnetization direction When the magnetization direction is antiparallel to the magnetization direction of the reference layer, the memory cell exhibits a high resistance, which can be stored as "1".
  • the reading of magnetic random access memory is to detect the resistance of the memory cell. A constant small current flows from the bit line through the MTJ, and a potential difference will be generated at both ends of the MTJ. According to the magnitude of the potential difference, the resistance of the MTJ can be determined, and then the information stored in the magnetic random access memory can be judged. "0" or "" 1".
  • the free layer will generate a large compensation field, which increases the current required for the flipping of the free layer and causes the MTJ flip to be asymmetrical.
  • the embodiments of the present application provide a memory and an electronic device, which can solve the problems of large current required for flipping of the free layer in an MTJ and asymmetric flipping of the MTJ.
  • a memory in a first aspect, includes a plurality of memory cells arranged in a storage area of the memory and distributed in an array, the memory cells include a transistor and a magnetic tunnel junction MTJ element connected to the transistor; the MTJ element includes a first electrode, a second electrode, and a first electrode and a second The MTJ between the two electrodes, the second electrode is electrically connected to the drain electrode of the transistor; the MTJ includes a first pinned layer, a first reference layer, a first tunneling layer and a free layer that are stacked in sequence; the first pinned layer is A ferrimagnetic or antiferromagnetic material with magnetic anisotropy, and the static magnetic field generated by the first pinning layer in the space where the free layer is located is smaller than the coercive magnetic field of the free layer.
  • the static magnetic field generated by the first pinning layer in the space where the free layer is located is smaller than the coercive magnetic field of the free layer, the static magnetic field generated by the first pinning layer in the space where the free layer is located will not affect the magnetization direction of the free layer, so that As a result, the free layer will not generate a compensation field due to the static magnetic field generated by the first pinning layer in the space where the free layer is located.
  • the current required for the flipping of the free layer can be reduced, and the asymmetry of MTJ flipping can be solved. The problem.
  • the magnetization direction of the first pinned layer is parallel to the stacking direction of the layers in the MTJ, so that an MTJ with perpendicular magnetic anisotropy can be formed.
  • the material of the first pinning layer includes one or more of rare earth transition metal alloy, yttrium manganese alloy, iron manganese alloy or platinum manganese alloy.
  • the material of the first pinning layer is an amorphous material. Since the amorphous material is self-contained rather than interfacial, there is no requirement for the growth interface, so it is not sensitive to roughness and stress. In this way, the inconsistency of the first pinning layer caused by the accumulation of roughness and stress can be solved. Stablize.
  • the MTJ further includes a second tunneling layer, a second reference layer and a second pinning layer that are sequentially stacked and disposed on the side of the free layer away from the first tunneling layer;
  • the magnetization direction is opposite to the magnetization direction of the second pinning layer, and the resistance of the first tunneling layer is different from that of the second tunneling layer. Since both the first reference layer and the second reference layer can provide spin transfer torque, the current required for flipping the free layer can be greatly reduced. In theory, the current required for flipping the free layer can be reduced by 50%, thereby improving power consumption.
  • the MTJ further includes a non-magnetic layer and a second pinned layer that are sequentially stacked on the side of the free layer away from the first tunneling layer; the magnetization direction of the first pinned layer is the same as the second pinned layer.
  • the magnetization directions of the layers are opposite. Since both the first reference layer and the second pinning layer can provide spin transfer torque, the current required for the flipping of the free layer can be greatly reduced. In theory, the current required for flipping the free layer can be reduced by 50%, thereby improving power consumption.
  • the second pinned layer, the non-magnetic layer and the free layer constitute a spin valve structure.
  • the spin valve structure formed in the MTJ does not need to use the second tunneling layer, and the material of the non-magnetic layer is metal Therefore, the overall resistance of the MTJ is reduced, so that the read and write current can be reduced, the power consumption of the memory can be further reduced, the durability of the MTJ can be improved, and the life of the memory can be extended.
  • the second pinning layer is a ferrimagnetic or antiferromagnetic material with perpendicular magnetic anisotropy, and the static magnetic field generated by the second pinning layer in the space where the free layer is located is smaller than that of the free layer the coercive field. Since the static magnetic field generated by the first pinned layer in the space where the free layer is located is small, and the static magnetic field generated by the second pinned layer in the space where the free layer is located is also small, in this way, the first pinned layer and the second pinned layer are relatively small. Neither of the two pinned layers will affect the free layer, and compared with the prior art, the current required for the flipping of the free layer can be reduced, and the problem of asymmetric flipping of the MTJ can be solved.
  • the material of the second pinning layer includes one or more of rare earth transition metal alloys, yttrium manganese alloys, iron-manganese alloys or platinum-manganese alloys.
  • the material of the second pinning layer is an amorphous material. Since the amorphous material is self-contained rather than interfacial, there is no requirement for the growth interface, so it is not sensitive to roughness and stress. In this way, the inconsistency of the second pinning layer caused by the accumulation of roughness and stress can be solved. Stablize.
  • the first electrode is located on the side of the first pinned layer away from the free layer
  • the second electrode is located on the side of the free layer away from the first tunneling layer, and is in contact with the free layer;
  • the second electrode Multiplexing provides layers for spin-orbit torque. Since, on the one hand, the first reference layer provides the spin shift distance STT flips the free layer, and on the other hand, the spin-orbit moment providing layer provides the spin-orbit moment SOT flips the free layer. Since the free layer is flipped by the spin shift distance STT and the spin-orbit moment SOT at the same time, the current required for the flipping of the free layer can be greatly reduced.
  • the material of the second electrode is one or more of a heavy metal element, a heavy metal alloy, a topological insulator or a Weyl semimetal.
  • the second electrode can be multiplexed as a spin-orbit torque providing layer.
  • the material of the first reference layer and the free layer includes a cobalt iron boron CoFeB alloy; the material of the first tunneling layer includes magnesium oxide MgO.
  • the gate electrode of the transistor is connected to the word line control circuit through the word line WL, the source electrode of the transistor is connected to the source line SL; the first electrode is connected to the bit line control circuit through the bit line BL.
  • the word line control circuit can control the supply of the signal to the word line WL, and the bit line control circuit can control the supply of the signal to the bit line BL.
  • an electronic device in a second aspect, includes a circuit board and a memory electrically connected to the circuit board, where the memory is the above-mentioned memory.
  • the electronic device has the same technical effects as the foregoing embodiments, which will not be repeated here.
  • FIG. 1a is a schematic structural diagram of a storage system according to an embodiment of the present application.
  • FIG. 1b is a schematic structural diagram of a storage system according to another embodiment of the present application.
  • FIG. 1c is a schematic structural diagram of a storage system according to another embodiment of the present application.
  • FIG. 2 is a schematic structural diagram of a memory according to an embodiment of the present application.
  • 3a is a schematic structural diagram of an MTJ element provided by an embodiment of the present application.
  • 3b is a schematic structural diagram of an MTJ element provided by another embodiment of the present application.
  • 6a is a schematic structural diagram of an MTJ element provided by another embodiment of the present application.
  • 6b is a schematic structural diagram of an MTJ element provided by yet another embodiment of the present application.
  • FIG. 7 is a schematic structural diagram of an MTJ element provided by another embodiment of the present application.
  • FIG. 8 is a schematic structural diagram of an MTJ element provided by another embodiment of the present application.
  • FIG. 9 is a schematic structural diagram of an MTJ element according to yet another embodiment of the present application.
  • first”, second, etc. are only used for convenience of description, and should not be construed as indicating or implying relative importance or implying the number of indicated technical features. Thus, a feature defined as “first”, “second”, etc., may expressly or implicitly include one or more of that feature.
  • electrical connection may be a direct electrical connection or an indirect electrical connection through an intermediate medium.
  • the technical solutions provided in this application can be applied to various storage systems using magnetic random access memory.
  • the technical solution provided in this application is applied to a computer.
  • the technical solution provided in this application is applied to a storage system including a memory, or a processor and a memory, and the processor may be a central processing unit (CPU), artificial intelligence (artificial intelligence, AI) processing devices, digital signal processors, and neural network processors.
  • CPU central processing unit
  • AI artificial intelligence
  • digital signal processors digital signal processors
  • neural network processors neural network processors.
  • FIG. 1a is a schematic structural diagram of a storage system according to an embodiment of the present application.
  • the storage system may include a storage device, and the storage device may be a magnetic random access memory.
  • the storage system may further include a CPU, a cache (cache), a controller, and the like.
  • the storage system includes an integrated CPU, a buffer and a storage device.
  • the storage system can be used as an independent memory, and the storage system includes an integrated CPU, a buffer, a controller and a storage device, and the storage device passes through the controller. coupled with the buffer and the CPU.
  • the storage system includes a storage device, and an integrated CPU, a buffer, a controller and a dynamic random access memory (DRAM), and the storage device can The DRAM is coupled as an external storage device; wherein the DRAM is coupled to the buffer and the CPU through the controller.
  • the CPUs in the various memory systems shown in Figures 1a, 1b and 1c may also be replaced by CPU cores.
  • the storage devices in FIGS. 1a, 1b and 1c may be magnetic random access memories.
  • the structure of the memory 10 includes a plurality of storage units 11 arranged in an array and distributed in a storage area of the memory.
  • 11 includes a transistor T and a magnetic tunnel junction MTJ element 12 connected to the transistor T.
  • the memory 10 further includes a plurality of word lines (word lines, WL) arranged in parallel and a plurality of bit lines (bit lines, BL) arranged in parallel, and the word lines WL and the bit lines BL cross each other, for example, the word lines WL and the bit lines The lines BL are perpendicular to each other.
  • the memory 10 further includes a plurality of source lines (SL) arranged in parallel, and the source lines SL are parallel to the bit lines BL.
  • the gate electrode of the transistor T is electrically connected to the word line WL, and the source electrode of the transistor T is electrically connected to the source line SL.
  • the word line WL is also electrically connected to a word line control circuit, and the word line control circuit provides a high level signal or a low level signal for the word line WL, so that the transistor T is turned on or off.
  • the transistor T is an N-type transistor
  • the high-level signal controls the transistor T to be turned on
  • the low-level signal controls the transistor T to be turned off.
  • the transistor T is a P-type transistor
  • a low-level signal controls the transistor T to be turned on
  • a high-level signal controls the transistor T to be turned off.
  • the source line SL is grounded.
  • the MTJ element 12 includes a first electrode 121 , a second electrode 122 and an MTJ located between the first electrode 121 and the second electrode 122 , and the second electrode 122 is electrically connected to the drain electrode of the transistor T .
  • the first electrode 121 is electrically connected to the bit line BL.
  • bit line BL is also electrically connected to a bit line control circuit, and the bit line BL is provided with a signal through the bit line control circuit.
  • the MTJ includes a first pinned layer 1231, a first reference layer 1232, a first tunneling layer 1233 and a free layer 1234, which are stacked in sequence; wherein, the first pinned layer 1231 has a magnetic Anisotropic ferrimagnetic or antiferromagnetic material, and the static magnetic field (ie stray field) generated by the first pinning layer 1231 in the space where the free layer 1234 is located is smaller than the coercive magnetic field (coercive force) of the free layer 1234 .
  • the free layer 1234 may be close to the first electrode 121 , and the first pinned layer 1231 may be close to the second electrode 122 ;
  • the first reference layer 1232 is a film layer with a fixed magnetization direction in the MTJ, and there is a strong exchange coupling between the first pinning layer 1231 and the first reference layer (also referred to as a pinned layer) 1232 As a result, the direction of the magnetic moment of the first reference layer 1232 (also referred to as the magnetization direction) can be pinned in a fixed direction by the first pinned layer 1231, and the direction of the magnetic moment of the first reference layer 1232 is difficult to be changed.
  • the magnetization direction of a reference layer 1232 is the same as that of the first pinning layer 1231 .
  • the first pinned layer 1231 is used to pin the magnetization direction of the first reference layer 1232 in a fixed direction, so the magnetization direction of the first pinned layer 1231 should not be easily changed, that is, the first pinned layer 1231 should have Larger coercive field.
  • the first reference layer 1232 and the free layer 1234 are in a decoupling state due to the action of the first tunneling layer 1233. Therefore, the magnetization direction of the free layer 1234 is easily changed under the action of an external magnetic field.
  • the magnetization direction and the magnetization direction of the first reference layer 1231 may be parallel or anti-parallel.
  • the magnetization direction of each layer in the memory cell 11 needs to be initialized.
  • the specific process is as follows: applying a large external magnetic field to make the magnetization directions of the first pinned layer 1231 , the first reference layer 1232 and the free layer 1234 the same to initialize the magnetization directions of the layers in the memory cell 11 .
  • the material of the first pinning layer 1231 is a ferrimagnetic or antiferromagnetic material, the first pinning layer 1231 not only has the initialized magnetization direction generated by the external magnetic field, but also has the same initialized magnetization.
  • the direction of magnetization is antiparallel to the magnetization direction, but the magnetic field of the magnetization direction antiparallel to the initialized magnetization direction is very weak.
  • the thick arrows marked in the first pinning layer 1231 are the initialized magnetization directions
  • the thin arrows are the magnetization directions antiparallel to the initialized magnetization directions. It can be understood that the thick arrows marked by the first pinned layer 1231 are the magnetization directions of the first pinned layer 1231 .
  • the magnetization direction of the first pinned layer 1231 is parallel to the stacking direction of the layers in the MTJ.
  • the first pinning layer 1231 is a ferrimagnetic or antiferromagnetic material with perpendicular magnetic anisotropy (PMA).
  • the stacking direction of each layer in the MTJ can be from the first pinned layer 1231 to the free layer 1234 , or from the free layer 1234 to the first pinned layer 1231 .
  • the stacking direction of the first pinned layer 1231 is parallel to the stacking direction of each layer in the MTJ, and the magnetization direction of the first pinned layer 1231 may be the same as the stacking direction of each layer in the MTJ (ie, the first pinned layer
  • the magnetization direction of 1231 is the direction from the first pinned layer 1231 to the free layer 1234); it can also be that the magnetization direction of the first pinned layer 1231 is parallel and opposite to the stacking direction of each layer in the MTJ (ie the first pinned layer
  • the magnetization direction of 1231 is the direction from the free layer 1234 to the first pinned layer 1231).
  • the magnetization direction of the first pinned layer 1231 is parallel to the stacking direction of the layers in the MTJ
  • the first reference layer 1232 since the magnetization direction of the first reference layer 1232 is the same as the magnetization direction of the first pinned layer 1231, the first reference layer 1232 The magnetization direction of is also parallel to the stacking direction of the layers in the MTJ.
  • the MTJ formed at this time is an MTJ with perpendicular magnetic anisotropy, and the MTJ with perpendicular magnetic anisotropy has the advantages of low write energy and miniaturization.
  • the magnetization direction of the first pinned layer 1231 is perpendicular to the stacking direction of the layers in the MTJ.
  • the magnetization direction of the first pinned layer 1231 may be leftward perpendicular to the stacking direction of the layers in the MTJ, or may be perpendicular to the stacking direction of the layers in the MTJ to the right.
  • FIG. 3b illustrates an example in which the magnetization direction of the first pinned layer 1231 is perpendicular to the stacking direction of each layer in the MTJ to the right.
  • the magnetization direction of the first pinned layer 1231 is perpendicular to the stacking direction of the layers in the MTJ
  • the magnetization direction of the first reference layer 1232 is the same as the magnetization direction of the first pinned layer 1231, the first reference layer 1232
  • the magnetization direction of is also perpendicular to the stacking direction of the layers in the MTJ.
  • the first tunneling layer 1233 is a non-magnetic layer, and the material of the first tunneling layer 1233 may include, for example, one or more of magnesium oxide (MgO) or aluminum oxide (Al 2 O 3 ).
  • MgO magnesium oxide
  • Al 2 O 3 aluminum oxide
  • first reference layer 1232 and the free layer 1234 are magnetic layers, and the materials of the first reference layer 1232 and the free layer 1234 may include, for example, a cobalt iron boron (CoFeB) alloy, a cobalt iron (CoFe) alloy, or a nickel iron cobalt (NiFeCo) alloy. one or more of the alloys.
  • the transistor T When the memory cell 11 is writing, the transistor T is in an on state, and when the current direction flows from the free layer 1234 to the first reference layer 1232, that is, the spin electrons flow from the first reference layer 1232 to the free layer 1234, and the spin electrons pass through the first reference layer 1232.
  • the electrons in the current are spin polarized along the magnetization direction of the first reference layer 1232, the spin magnetic moment of the electrons is parallel to the magnetization direction of the first reference layer 1232, and the electrons pass through the first tunneling layer
  • the spin electrons transfer the spin torque (also known as spin angular momentum, or STT) to the free layer 1234, and the free layer 1234 subjected to the effect of the spin torque has a small magnetization, so it is free.
  • spin torque also known as spin angular momentum, or STT
  • the magnetization direction of the layer 1234 can be freely changed according to the polarization direction of the spin electrons in the spin current, and finally the magnetization direction of the free layer 1234 and the magnetization direction of the first reference layer 1232 are in a parallel state (that is, the magnetization of the free layer 1234).
  • the direction is the same as the magnetization direction of the first reference layer 1232), which can represent that the written information is "0".
  • the antiparallel state (ie, the magnetization direction of the free layer 1234 is opposite to the magnetization direction of the first reference layer 1232 ), may represent that the written information is "1".
  • the current direction can be controlled by the voltage provided on the bit line BL and the source line SL. Referring to FIG. 3a, when the voltage provided by the bit line BL is greater than the voltage provided by the source line SL, the current flows from the free layer 1234 to the first reference layer. 1232 ; when the voltage provided by the bit line BL is lower than the voltage provided by the source line SL, the current flows from the first reference layer 1232 to the free layer 1234 .
  • the resistance of the MTJ can be determined, that is, the relative orientation relationship between the magnetization directions of the free layer 1234 and the first reference layer 1232 can be obtained, and then it can be determined whether the information stored in the memory unit 11 is “0” or “1” .
  • the MTJ exhibits low resistance, the magnetization direction of the free layer 1234 is parallel to the magnetization direction of the first reference layer 1232, and the information stored in the memory cell 11 is “0”; the MTJ exhibits high resistance, and the magnetization direction of the free layer 1234 is the same as The magnetization direction of the first reference layer 1232 is in an anti-parallel state, and the information stored in the memory unit 11 is "1".
  • the word line control circuit provides a gate signal to the word lines row by row, so that the transistors T in the multi-row memory cells 11 are turned on row by row, so that writing can be performed row by row. Enter information or read information.
  • the memory 10 provided in this embodiment of the present application may also be referred to as a spin-shift magnetic random access memory.
  • the static magnetic field generated by the first pinned layer 1231 in the space where the free layer 1234 is located is related to the magnetic moment of the first pinned layer 1231 . The smaller the static magnetic field generated by 1231 in the space where the free layer 1234 is located.
  • the first pinned layer 1231 is a ferrimagnetic or antiferromagnetic material with magnetic anisotropy, a static magnetic field is generated around the first pinned layer 1231 , and the free layer 1234 is located around the first pinned layer 1231 (eg above), so the first pinned layer 1231 will generate a magnetic field in the space where the free layer 1234 is located, and the space where the free layer 1234 is located refers to the space range around the first pinned layer 1231 occupied by the free layer 1234, here The space where the free layer 1234 is located intersects with the range of the static magnetic field generated by the first pinned layer 1231 , or the space where the free layer 1234 is located is completely within the range of the static magnetic field generated by the first pinned layer 1231 .
  • the static magnetic field generated by the first pinned layer 1231 in the space where the free layer 1234 is located is less than 1000 oersteds (Oe)
  • the static magnetic field generated by the first pinned layer 1231 in the space where the free layer 1234 is located is less than 1000 oersteds (Oe).
  • the magnetic field is less than the coercive field of the free layer 1234 .
  • the magnetic field strength of the static magnetic field generated by the first pinned layer 1231 in the space where the free layer 1234 is located is 0, or about 0, that is, the first pinned layer 1231 does not generate stray fields, or generates The stray field approaches 0. At this time, the magnetic moment of the first pinning layer 1231 is zero, or about zero.
  • the material of the first pinning layer 1231 includes rare earth transition metal alloy (RE-TM), rare earth transition metal alloy-based magnetic doping compound, yttrium manganese (YMn) One or more of alloys, iron manganese (FeMn) alloys, or platinum manganese (PtMn) alloys.
  • RE-TM rare earth transition metal alloy
  • YMn yttrium manganese
  • FeMn iron manganese
  • PtMn platinum manganese
  • the rare earth transition metal alloy may be a CoTb (cobalt terbium) alloy or a CoGd (cobalt gadolinium) alloy.
  • the rare earth transition metal alloy based magnetic doping compound may be a CoTb alloy or CoGd alloy based magnetic doping compound.
  • the rare earth transition metal alloy and the magnetic doping compound based on the rare earth transition metal alloy are ferrimagnetic materials having perpendicular magnetic anisotropy.
  • the magnetic moment (Ms) of the material can be controlled by controlling the composition and thickness of the material, so that the The magnetic moment of the first pinned layer 1231 is small, close to 0, that is, the static magnetic field generated by the first pinned layer 1231 in the space where the free layer 1234 is located is smaller than the coercive magnetic field of the free layer 1234 .
  • Figure 4 shows the relationship between the magnetic moment of the rare earth transition metal alloy and the transition metal in the rare earth transition metal alloy when other factors (such as the growth method or thickness of the rare earth transition metal alloy) are constant. relationship between the proportions.
  • the magnetic moment of the rare earth transition metal alloy when the proportion of transition metals in the rare earth transition metal alloy changes, the magnetic moment of the rare earth transition metal alloy also changes. Specifically, as the proportion of transition metal increases, the magnetic moment of the rare earth transition metal alloy gradually decreases. When the proportion of transition metal increases to a certain value, as the proportion of transition metal increases, the rare earth transition metal alloy gradually decreases. The magnetic moment of the metal alloy gradually increases again. According to the relationship between the magnetic moment of the rare earth transition metal alloy and the proportion of transition metal in the rare earth transition metal alloy, the magnetic moment of the first pinning layer 1231 can be close to 0 by adjusting the ratio of rare earth and transition metal.
  • the coercive field (Hc) of the material can also be controlled by controlling the material composition and thickness, so that the coercive field of the first pinning layer 1231 is larger.
  • the coercive field of the first pinning layer 1231 is relatively large, the magnetization direction of the first pinning layer 1231 is not easily changed under the action of an external magnetic field, and the first pinning layer 1231 is exchange-coupled with the first reference layer 1232, so that the pinning first The effect of a reference layer 1232.
  • the structure of the MTJ includes a pinned layer, a reference layer, a tunneling layer and a free layer that are stacked in sequence, wherein the pinned layer is mainly composed of a metal layer (non-ferromagnetic, such as Pt) and iron.
  • An artificial antiferromagnetic layer formed by alternating magnetic layers (such as Co or Fe), the reference layer and the free layer include CoFeB alloy, and the tunneling layer includes MgO.
  • the pinned layer is mainly an artificial antiferromagnetic layer formed by alternating metal layers and ferromagnetic layers
  • the pinned layer has a large stray field, that is, a large static magnetic field is generated in the space where the free layer 1234 is located, so that the As a result, the free layer will generate a larger compensation field, which increases the current required for the free layer to flip, and causes the MTJ to flip asymmetrically, that is, to change the magnetization direction of the free layer in two opposite directions.
  • the current magnitudes are different.
  • the stray field generated by the pinned layer is mainly edge effect, and has little effect on the flipping of the free layer.
  • the magnetization direction of the pinned layer is parallel to the MTJ
  • the stray field basically acts in the direction parallel to the stacking direction of each layer in the MTJ, so the acting field is very large in the direction parallel to the stacking direction of each layer in the MTJ, and the free layer is very large. Flip suffers a lot. Based on this, since the size of the storage unit 11 in the memory 10 is getting smaller and smaller, the influence of the stray field is getting bigger and bigger. Furthermore, in highly integrated MTJ arrays, this problem is exacerbated.
  • the embodiment of the present application provides a memory 10, the structure of the memory 10 includes a plurality of memory cells 11 arranged in an array in a storage area of the memory, and the memory cells 11 include a transistor T and a magnetic tunnel junction MTJ element 12 connected to the transistor T. .
  • the MTJ element 12 includes a first electrode 121 , a second electrode 122 , and an MTJ located between the first electrode 121 and the second electrode 122 , and the second electrode 122 is electrically connected to the drain electrode of the transistor T.
  • the MTJ includes a first pinned layer 1231 , a first reference layer 1232 , a first tunneling layer 1233 and a free layer 1234 that are stacked in sequence; the first pinned layer 1231 is ferrimagnetic or antiferromagnetic with magnetic anisotropy material, and the static magnetic field generated by the first pinned layer 1231 in the space where the free layer 1234 is located is smaller than the coercive magnetic field of the free layer 1234 .
  • the static magnetic field generated by the first pinned layer 1231 in the space where the free layer 1234 is located is smaller than the coercive magnetic field of the free layer 1234 , the static magnetic field generated by the first pinned layer 1231 in the space where the free layer 1234 is located will not affect the free layer In this way, the free layer 1234 will not generate a compensation field due to the static magnetic field generated by the first pinning layer 1231 in the space where the free layer 1234 is located, which can reduce the need for flipping the free layer 1234 compared to the prior art. current, and can solve the problem of MTJ flip asymmetry.
  • the static magnetic field generated by the first pinned layer 1231 in the space where the free layer 1234 is located is smaller than the coercive magnetic field of the free layer 1234, the static magnetic field generated by the first pinned layer 1231 in the space where the free layer 1234 is located will not affect the free layer 1234. Therefore, there is no need to increase the current to overcome the difference in the influence of stray fields on the free layer 1234, so that the magnetization direction of the free layer 1234 can be reversed with a smaller current, which can reduce the power, It can also improve the durability of the MTJ and improve the life of the MTJ.
  • the first reference layer 1232 will also generate a static magnetic field in the space where the free layer 1234 is located, that is, a stray field, but because the static magnetic field generated by the first reference layer 1232 in the space where the free layer 1234 is located is very small, substantially smaller than The coercive magnetic field of the free layer 1234 will not affect the free layer 1234, so the static magnetic field generated by the first reference layer 1232 in the space where the free layer 1234 is located can be ignored.
  • the pinned layer is an artificial antiferromagnetic layer formed by alternating metal layers and ferromagnetic layers.
  • the film structure is 111 crystal orientation, while the tunneling layer (material is MgO) and the free layer (material is CoFeB)
  • the annealed structure is a 001 structure. Due to the large lattice difference between the pinned layer and the tunneling layer and the free layer, the accumulation of stress and roughness will lead to the instability of the pinned layer, such as weak perpendicular magnetic direction. Based on this, in some embodiments of the present application, the material of the first pinning layer 1231 is amorphous.
  • the material of the first pinning layer 1231 includes rare earth transition metal alloys and magnetic doping compounds based on rare earth transition metal alloys.
  • the material of the first pinning layer 1231 is an amorphous material, and the amorphous material is a self-type rather than an interface type, there is no requirement for the growth interface, so it is not sensitive to roughness and stress. , the instability of the first pinning layer 1231 caused by the accumulation of roughness and stress can be resolved.
  • the first electrode 121 is located on the side of the first pinned layer 1231 away from the free layer 1234
  • the second electrode 122 is located at the side of the free layer 1234 away from the first tunneling layer 1233
  • One side is in contact with the free layer 1234; the second electrode 122 is multiplexed as a spin orbit torque (spin orbit torque, SOT for short) providing layer.
  • the material of the second electrode 122 may be, for example, one or more of a heavy metal element, a heavy metal alloy, a topological insulator or a Weyl semimetal.
  • the heavy metal element may be one or more of platinum (Pt), tantalum (Ta), copper (Cu), iridium (Ir), ruthenium (Ru) or tungsten (W).
  • the heavy metal alloy may be an alloy composed of two or more of platinum, tantalum, copper, iridium, ruthenium or tungsten.
  • the topological insulator may be one or more of a bismuth selenide (Bi 2 Se 3 ) compound, an antimony telluride (Sb 2 Te 3 ) compound, or a bismuth telluride (Bi 2 Te 3 ) compound.
  • the Weyl semimetal may be tungsten ditelluride (WTe 2 ).
  • the spin-orbit moment providing layer may be one layer or multiple layers.
  • the principle of the spin-orbit torque providing layer flipping the free layer 1234 is that the current flowing through the spin-orbit torque providing layer can generate a spin current, which acts on the magnetic layer (such as the free layer 1234 ), and the generated spin-orbit torque SOT induces the free layer 1234
  • the magnetization is reversed, and by passing forward or reverse current in the spin-orbit torque providing layer, electrons with different spin directions act on the magnetic layer, so that a high-resistance state (marked as "1") or a low-resistance state can be achieved. Resist state (denoted as "0") write.
  • the second electrode 122 is multiplexed as a spin-orbit torque providing layer, in some examples, as shown in FIG. 6a, the second electrode 122 is electrically connected to the drain electrode of a transistor T whose gate electrode is connected to The word line WL is electrically connected, and the source electrode is connected to the source line SL.
  • the source line SL may be grounded.
  • the writing process of the MTJ is that the transistor T is turned on, and the bit line BL writes current.
  • the first reference layer 1232 provides the spin shift distance STT to flip the free layer 1234, and on the other hand, the spin-orbit torque
  • the supply layer provides the spin-orbit moment SOT flip free layer 1234 . Since the free layer 1234 is flipped by the spin shift distance STT and the spin-orbit moment SOT at the same time, the current required for flipping the free layer 1234 can be greatly reduced.
  • the reading process of the MTJ is the same as the above-mentioned reading process, and will not be repeated here.
  • the second electrode 122 is electrically connected to the drain electrodes of the two transistors (transistor T1 and transistor T2 ) respectively, and the drain electrodes of the transistor T1 are connected to the second electrode 122 at points A and The position point B where the drain electrode of the transistor T2 is connected to the second electrode 122 is located at the two ends of the second electrode 122 along the cross section perpendicular to the second electrode 122.
  • the gate electrode of the transistor T1 is electrically connected to the word line WL1, and the source electrode and the source electrode are electrically connected.
  • the line SL1 is connected, the gate electrode of the transistor T2 is electrically connected to the word line WL2, and the source electrode is connected to the source line SL2.
  • the second electrode 122 is electrically connected to the drain electrode of the transistor T1 and the drain electrode of the transistor T2 respectively, and the point A where the drain electrode of the transistor T1 is connected to the second electrode 122 is connected to the drain electrode of the transistor T2 and the second electrode 122
  • the position point B is located at both ends of the second electrode 122 along the cross section perpendicular to the second electrode 122 , so the spin-orbit torque supplying layer on the entire surface can provide the spin-orbit torque SOT, thereby improving the turnover efficiency of the free layer 1234 and reducing the the current required to flip the free layer 1234.
  • the MTJ has two working modes, the first one, the bit line BL writes the current, the first reference layer 1232 provides the spin shift distance STT flips the free layer 1234, at the same time, the word line WL1 provides the strobe signal, the transistor T1 is turned on, the word line WL2 provides a gate signal, the transistor T2 is turned on, the source line SL1 and the source line SL2 write current, and the spin-orbit torque supply layer provides the spin-orbit torque SOT to flip the free layer 1234 . Since the free layer 1234 is flipped by the spin shift distance STT and the spin-orbit moment SOT at the same time, the current required for flipping the free layer 1234 can be greatly reduced.
  • the bit line BL writes the current
  • the first reference layer 1232 provides the spin shift distance STT inversion free layer 1234
  • the word line WL1 provides a strobe signal
  • the transistor T1 is turned off
  • the word line WL2 provides When the strobe signal is turned on, the transistor T2 is turned off.
  • the spin-orbit torque supply layer does not work, that is, the spin-orbit torque SOT is not provided; at the second moment, the bit line BL does not write current, that is, the current is 0.
  • the first reference layer 1232 does not provide the spin shift distance STT
  • the word line WL1 provides a gate signal
  • the transistor T1 is turned on
  • the word line WL2 provides a gate signal
  • the transistor T2 is turned on
  • the source line SL1 and the source line SL2 are written
  • the current, the spin-orbit moment supply layer provides the spin-orbit moment SOT to flip the free layer 1234; the first moment and the second moment are alternated, that is, the spin shift distance STT and the spin-orbit moment SOT alternately flip the free layer 1234, thereby being able to greatly
  • the current required to flip the free layer 1234 is reduced.
  • the spin-orbit torque providing layer can provide a larger spin-orbit torque SOT to flip the free layer 1234, so as to improve the flipping efficiency of the free layer 1234.
  • the MTJ includes a first pinning layer 1231, a first reference layer 1232, a first tunneling layer 1233, a free layer 1234, a second tunneling layer 1235, a second reference layer 1236, and a second tunneling layer 1235, which are stacked in sequence.
  • Two pinned layers 1237 wherein, the magnetization directions of the first pinned layer 1231 and the second pinned layer 1237 are parallel to the stacking direction of each layer in the MTJ, and the magnetization direction of the first pinned layer 1231 and the second pinned layer
  • the magnetization directions of 1237 are opposite, and the resistance of the first tunneling layer 1233 is different from that of the second tunneling layer 1235 .
  • the first pinned layer 1231 is used to pin the magnetization direction of the first reference layer 1232 in a fixed direction
  • the magnetization direction of the first reference layer 1232 is the same as the magnetization direction of the first pinned layer 1231
  • the pinned layer 1237 is used to pin the magnetization direction of the second reference layer 1236 in a fixed direction
  • the magnetization direction of the second reference layer 1236 is the same as the magnetization direction of the second pinned layer 1237 . Since the magnetization direction of the first pinned layer 1231 is opposite to that of the second pinned layer 1237 , the magnetization direction of the first reference layer 1232 is opposite to that of the second reference layer 1236 .
  • the coercive forces of the first pinned layer 1231 and the second pinned layer 1237 are different, for example, the coercive force of the first pinned layer 1231 is greater than the coercive force of the second pinned layer 1237 .
  • the coercive force of the first pinning layer 1231 can be adjusted by adjusting the thickness of the first pinning layer 1231
  • the coercive force of the second pinning layer 1237 can be adjusted by adjusting the thickness of the second pinning layer 1237
  • the coercivity of the first reference layer 1232 and the second reference layer 1236 are also different, for example, the coercivity of the first reference layer 1232 is greater than the coercivity of the second reference layer 1236 (the first nail The coercive force of the pinned layer 1231 is greater than the coercive force of the second pinned layer 1237).
  • the coercive force of the first reference layer 1232 can be adjusted by adjusting the thickness of the first reference layer 1232
  • the coercive force of the second reference layer 1236 can be adjusted by adjusting the thickness of the second reference layer 1236 .
  • the specific process of initializing the memory cell 11 is as follows: first, as shown in FIG. 8 , a large external magnetic field is applied to make the first pinning layer 1231 , the first reference layer 1232 , the second pinning layer 1237 , the first pinning layer 1237 , the The magnetization directions of the second reference layer 1236 and the free layer 1234 are the same; then, as shown in FIG. 7 , a small external magnetic field is applied to make the magnetization directions of the second pinned layer 1237 and the second reference layer 1236 reverse to opposite directions .
  • the applied smaller external magnetic field can make the magnetization direction of the second pinned layer 1237 reverse to the opposite direction, but cannot The magnetization direction of the first pinning layer 1231 is reversed, while the magnetization direction of the first reference layer 1232 is pinned in a fixed direction by the first pinning layer 1231 and is difficult to change. Therefore, after applying a small external magnetic field, the first The magnetization direction of the reference layer 1232 will not be reversed.
  • the magnetization direction of the first pinned layer 1231 and the magnetization direction of the second pinned layer 1237 are opposite, and the magnetization direction of the first reference layer 1232 and the second reference layer 1232.
  • the magnetization directions of layer 1236 are opposite.
  • the second tunneling layer 1235 is a non-magnetic layer, and the material of the second tunneling layer 1235 may include, for example, one or more of magnesium oxide or aluminum oxide.
  • the material of the first tunneling layer 1233 and the material of the second tunneling layer 1235 may be the same or different.
  • the material of the second reference layer 1236 reference may be made to the material of the first reference layer 1232, which is not repeated here.
  • the material of the first reference layer 1232 and the material of the second reference layer 1236 may be the same or different.
  • the writing process of the MTJ is as follows: when the current flows from the second pinning layer 1237 to the first pinning layer 1231, that is, the spin electrons flow from the first pinning layer 1231 to the second pinning layer 1237, the spin When electrons pass through the first reference layer 1232, the electrons in the current are spin-polarized along the magnetization direction of the first reference layer 1232, the spin magnetic moment of the electrons is parallel to the magnetization direction of the first reference layer 1232, and the electrons pass through the first reference layer 1232.
  • the spin electrons transfer the spin torque, that is, the spin angular momentum to the free layer 1234, and the magnetization direction of the free layer 1234 can be free according to the polarization direction of the spin electrons in the spin current.
  • the magnetization direction of the free layer 1234 is parallel to the magnetization direction of the first reference layer 1232.
  • the spin electrons pass through the second tunneling layer 1235 to reach the second reference layer 1236, the magnetization direction of the second reference layer 1236 is different from that of the first reference layer 1236.
  • the magnetization direction of the first reference layer 1232 is opposite, and the spin magnetic moment of the electrons is parallel to the magnetization direction of the first reference layer 1232, so the spin electrons cannot pass through the second reference layer 1236.
  • the second reference layer 1236 will The angular momentum is transferred to the spin electrons, and the spin electrons are reflected to the free layer 1234 by the second reference layer 1236, further making the magnetization direction of the free layer 1234 and the magnetization direction of the first reference layer 1232 parallel.
  • the magnetization direction of 1234 is parallel to the magnetization direction of the second reference layer 1236 .
  • the current flows from the second pinning layer 1237 to the first tunneling layer 1237 .
  • the memory cell When the pinned layer 1231, or the current flows from the first pinned layer 1231 to the second pinned layer 1237, when the magnetization direction of the free layer 1234 is the same as the magnetization direction of the first pinned layer 1231 close to the first tunneling layer 1233, At this time, the memory cell is in a low resistance state, and the written information is "0"; when the magnetization direction of the free layer 1234 is opposite to the magnetization direction of the first pinned layer 1231 close to the first tunneling layer 1233, the memory cell is in a high state at this time. Resistance state, the write information is "1".
  • the reading process of the MTJ is similar to the reading process of the MTJ in the above-mentioned first embodiment, and reference may be made to the reading process of the MTJ in the above-mentioned first embodiment, which will not be repeated here.
  • both the first reference layer 1232 and the second reference layer 1236 can provide spin transfer torque, so the current required for the flipping of the free layer 1234 can be greatly reduced.
  • the current required for flipping the free layer 1234 It can be reduced by 50%, which can improve power consumption.
  • the static magnetic field generated by the first pinned layer 1231 in the space where the free layer 1234 is located is smaller than the coercive magnetic field of the free layer 1234
  • the static magnetic field generated by the first pinned layer 1231 in the space where the free layer 1234 is located is smaller than the coercive magnetic field of the free layer 1234 .
  • the magnetic field will not affect the magnetization direction of the free layer 1234.
  • the free layer 1234 will not generate a compensation field due to the static magnetic field generated by the first pinning layer 1231 in the space where the free layer 1234 is located.
  • the current required for the flipping of the free layer 1234 is reduced, and the problem of asymmetric flipping of the MTJ can be solved.
  • the second pinned layer 1237 is a ferrimagnetic or antiferromagnetic material with perpendicular magnetic anisotropy, and the static magnetic field generated by the second pinned layer 1237 in the space where the free layer 1234 is located is smaller than that of the free layer 1234 coercive field.
  • the static magnetic field generated by the second pinned layer 1237 in the space where the free layer 1234 is located is related to the magnetic moment of the second pinned layer 1237.
  • the static magnetic field generated by the second pinning layer 1237 in the space where the free layer 1234 is located is less than 1000 oersteds (Oe)
  • the static magnetic field generated by the second pinning layer 1237 in the space where the free layer 1234 is located is less than 1000 oersteds (Oe).
  • the magnetic field is less than the coercive field of the free layer 1234 .
  • the magnetic field strength of the static magnetic field generated by the second pinned layer 1237 in the space where the free layer 1234 is located is 0, or about 0, that is, the second pinned layer 1237 does not generate stray fields, or generates The stray field approaches 0. At this time, the magnetic moment of the second pinning layer 1237 is zero, or about zero.
  • the static magnetic field generated by the first pinned layer 1231 in the space where the free layer 1234 is located and the second pinned layer 1237 in the free layer 1234 can theoretically cancel each other out, but the first pinned layer 1231 and the second pinned layer 1237 are produced due to process fluctuations (for example, uneven etching, or uneven sputtering when sputtering thin films).
  • the thicknesses of the first pinned layer 1231 and the second pinned layer 1237 are not uniform, so the static magnetic field generated by the first pinned layer 1231 in the space where the free layer 1234 is located and the second pinned layer 1237 in the space where the free layer 1234 is located The static magnetic field generated in space cannot be completely canceled.
  • the static magnetic field generated by the first pinned layer 1231 in the space where the free layer 1234 is located is smaller than the coercive magnetic field of the free layer 1234
  • the static magnetic field generated by the second pinned layer 1237 in the space where the free layer 1234 is located is smaller than the coercive magnetic field of the free layer 1234 .
  • the magnetic field is smaller than the coercive magnetic field of the free layer 1234.
  • the static magnetic field generated by the first pinned layer 1231 in the space where the free layer 1234 is located is 0 (the magnetic moment of the first pinned layer 1231 is 0 at this time), and the second pinned layer 1231 has a magnetic moment of 0.
  • the static magnetic field generated by the layer 1237 in the space where the free layer 1234 is located is 0, (the magnetic moment of the second pinned layer 1237 is 0 at this time), so the static magnetic field generated by the first pinned layer 1231 in the space where the free layer 1234 is located is smaller, and the static magnetic field generated by the second pinned layer 1237 in the space where the free layer 1234 is located is also smaller, so that neither the first pinned layer 1231 nor the second pinned layer 1237 will generate the free layer 1234 Compared with the prior art, the current required for the flipping of the free layer 1234 can be reduced, and the problem of asymmetric flipping of the MTJ can be solved.
  • the material of the second pinning layer 1237 includes one or more of rare earth transition metal alloys, magnetic doping compounds based on rare earth transition metal alloys, yttrium manganese alloys, iron manganese alloys, or platinum manganese alloys kind.
  • the magnetic moment of the second pinned layer 1237 can be controlled by controlling the composition and thickness of the material of the second pinned layer 1237, so that the magnetic moment of the second pinned layer 1237 is small, close to 0, that is,
  • the static magnetic field generated by the second pinning layer 1237 in the space where the free layer 1234 is located is made smaller than the coercive magnetic field of the free layer 1234 .
  • the coercive field of the second pinning layer 1237 can also be controlled by controlling the material composition and thickness of the second pinning layer 1237 .
  • the material of the second pinning layer 1237 is an amorphous material.
  • Amorphous materials are, for example, rare earth transition metal alloys or magnetic doping compounds based on rare earth transition metal alloys.
  • the material of the second pinning layer 1237 is an amorphous material, and the amorphous material is self-type rather than interface type, there is no requirement for the growth interface, so it is not sensitive to roughness and stress. Thus, the instability of the second pinning layer 1237 caused by the accumulation of roughness and stress can be resolved.
  • the MTJ includes a first pinned layer 1231, a first reference layer 1232, a first tunneling layer 1233, a free layer 1234, a non-magnetic layer 1238, and a second pinned layer 1237 that are stacked in sequence; wherein, The magnetization directions of the first pinned layer 1231 and the second pinned layer 1237 are both parallel to the stacking direction of the layers in the MTJ, and the magnetization direction of the first pinned layer 1231 is opposite to that of the second pinned layer 1237 .
  • the second pinned layer 1237, the non-magnetic layer 1238, and the free layer 1234 constitute a spin valve structure.
  • the material of the non-magnetic layer 1238 may be, for example, Cu, Ta, Mo (molybdenum), Al 2 O 3 , MgO, MgAlO x (magnesium aluminum oxide).
  • the writing and reading process of the MTJ is similar to the writing and reading process of the MTJ in the second embodiment, and reference may be made to the above-mentioned embodiment, which will not be repeated here.
  • the static magnetic field generated by the first pinned layer 1231 in the space where the free layer 1234 is located is smaller than the coercive magnetic field of the free layer 1234
  • the static magnetic field generated by the first pinned layer 1231 in the space where the free layer 1234 is located is smaller than the coercive magnetic field of the free layer 1234 .
  • the magnetic field will not affect the magnetization direction of the free layer 1234.
  • the free layer 1234 will not generate a compensation field due to the static magnetic field generated by the first pinning layer 1231 in the space where the free layer 1234 is located.
  • the current required for the flipping of the free layer 1234 is reduced, and the problem of asymmetric flipping of the MTJ can be solved.
  • both the first reference layer 1232 and the second pinning layer 1237 can provide spin transfer torque, so the current required for the flipping of the free layer 1234 can be greatly reduced.
  • the current required for flipping the free layer 1234 can be reduced by 50% %, which can improve power consumption.
  • the spin valve structure formed in the MTJ does not need to use the second tunneling layer 1235, and when the material of the non-magnetic layer 1238 is metal, the overall resistance of the MTJ is reduced, which can reduce the The read and write current further reduces the power consumption of the memory 10 , improves the durability of the MTJ, and prolongs the life of the memory 10 .
  • the second pinned layer 1237 is a ferrimagnetic or antiferromagnetic material with perpendicular magnetic anisotropy, and the static magnetic field generated by the second pinned layer 1237 in the space where the free layer 1234 is located is smaller than that of the free layer 1234 coercive field.
  • the material of the second pinning layer 1237 is an amorphous material.
  • the second pinning layer 1237 in this embodiment is the same as the second pinning layer 1237 in the second embodiment above.
  • an embodiment of the present application further provides an electronic device, the electronic device includes a circuit board and a memory connected to the circuit board, where the memory can be any of the memories provided above.
  • the circuit board may be a printed circuit board (printed circuit board, PCB), of course, the circuit board may also be a flexible printed circuit board (flexible printed circuit board, FPC), etc., the circuit board is not limited in this embodiment.
  • the electronic device is different types of user equipment or terminal equipment such as a computer, a mobile phone, a tablet computer, a wearable device, and a vehicle-mounted device; the electronic device may also be a network device such as a base station.
  • the electronic device further includes a packaging substrate, the packaging substrate is fixed on the printed circuit board PCB by solder balls, and the memory is fixed on the packaging substrate by solder balls.
  • a non-transitory computer-readable storage medium for use with a computer having software for creating an integrated circuit, the computer-readable storage medium having stored thereon one or more Computer readable data structures, one or more computer readable data structures having reticle data used to manufacture the memory provided by any one of the illustrations provided above.

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Hardware Design (AREA)
  • Hall/Mr Elements (AREA)
  • Mram Or Spin Memory Techniques (AREA)

Abstract

本申请实施例提供一种存储器及电子设备，涉及存储器技术领域，可以解决MTJ中自由层翻转需要的电流大以及MTJ翻转不对称的问题。该存储器包括设置于存储器的存储区域内阵列分布的多个存储单元，所述存储单元包括晶体管和与所述晶体管连接的磁隧道结MTJ元件；所述MTJ元件包括第一电极、第二电极和位于所述第一电极和所述第二电极之间的MTJ，所述第二电极与所述晶体管的漏电极电连接；所述MTJ包括依次层叠设置的第一钉扎层、第一参考层、第一隧穿层和自由层；其中，所述第一钉扎层为具有磁各向异性的亚铁磁或反铁磁材料，且所述第一钉扎层在所述自由层所在的空间产生的静磁场小于所述自由层的矫顽磁场。

Description

一种存储器及电子设备 技术领域
本申请涉及存储器技术领域，尤其涉及一种存储器及电子设备。
背景技术
磁性随机存取存储器(magnetic random access memory，MRAM)是一种新型非易失性存储器。其中，自旋转移距磁性随机存取存储器(spin transfer torque magnetic random access memory，STT MRAM)因其具有速度快、功耗低、COMS(complementary metal-oxide-semiconductor，互补式金属氧化物半导体)兼容性好等优势，得到了广泛关注。
自旋转移距磁性随机存取存储器的读写功能由自旋转移距磁性随机存取存储器的存储单元来实现。存储单元的主要结构由磁隧道结(magnetic tunneling junction，MTJ)和晶体管组成。MTJ的结构主要由存储信息的自由层、隧穿层、固定磁化方向的参考层和钉扎层依次层叠组成。其中，参考层的磁化方向被钉扎层钉扎在某一方向磁化方向保持不变，自由层的磁化方向可以改变，电流由不同方向流过MTJ(电流由固定层流向自由层或者电流由自由层流向固定层)时，自由层的磁化方向会随之改变，当自由层的磁化方向和参考层的磁化方向平行时，存储单元呈现低电阻，即可存储为“0”；当自由层的磁化方向和参考层的磁化方向反平行时，存储单元呈现高电阻，即可存储为“1”。磁性随机存取存储器的读取是检测存储单元的电阻。恒定的小电流从位线流经MTJ，在MTJ的两端会产生电位差，根据电位差的大小，可以确定MTJ的电阻，进而可以判断磁性随机存取存储器存储的信息是“0”还是“1”。
目前，由于钉扎层具有较强的杂散场，因而导致自由层会产生较大的补偿场，这样一来，提高了自由层翻转需要的电流，且导致MTJ翻转不对称。
发明内容
本申请实施例提供一种存储器及电子设备，可以解决MTJ中自由层翻转需要的电流大以及MTJ翻转不对称的问题。
为达到上述目的，本申请采用如下技术方案：
第一方面，提供一种存储器。该存储器包括设置于存储器的存储区域内阵列分布的多个存储单元，存储单元包括晶体管和与晶体管连接的磁隧道结MTJ元件；MTJ元件包括第一电极、第二电极和位于第一电极和第二电极之间的MTJ，第二电极与晶体管的漏电极电连接；MTJ包括依次层叠设置的第一钉扎层、第一参考层、第一隧穿层和自由层；第一钉扎层为具有磁各向异性的亚铁磁或反铁磁材料，且第一钉扎层在自由层所在的空间产生的静磁场小于自由层的矫顽磁场。由于第一钉扎层在自由层所在的空间产生的静磁场小于自由层的矫顽磁场，因此第一钉扎层在自由层所在的空间产生的静磁场不会影响自由层的磁化方向，这样一来，自由层不会因为第一钉扎层在自由层所在的空间产生的静磁场而产生补偿场，相对于现有技术便可以降低自由层翻转 需要的电流，且可以解决MTJ翻转不对称的问题。此外，无需提高电流来克服杂散场对自由层的影响存在的差异，这样一来，便可以利用较小的电流对自由层的磁化方向进行翻转，既可以降低功率，又可以提高MTJ的耐久性，提高了MTJ的寿命。
在一种可能的实施方式中，第一钉扎层的磁化方向平行于MTJ中各层的堆叠方向，这样便可以形成具有垂直磁各向异性的MTJ。
在一种可能的实施方式中，第一钉扎层的材料包括稀土过渡金属合金、钇锰合金、铁锰合金或铂锰合金中的一种或多种。此时，通过调整材料组分，便可以使得第一钉扎层在自由层所在的空间产生的静磁场小于自由层的矫顽磁场。
在一种可能的实施方式中，第一钉扎层的材料为非晶材料。由于非晶材料是自体式而非界面式，对生长界面没有要求，因而对粗糙度和应力不敏感，这样一来，便可以解决因粗糙度和应力累积导致的第一钉扎层产生的不稳定。
在一种可能的实施方式中，MTJ还包括依次层叠设置在自由层远离第一隧穿层一侧的第二隧穿层、第二参考层和第二钉扎层；第一钉扎层的磁化方向与第二钉扎层的磁化方向相反，第一隧穿层的电阻与第二隧穿层的电阻不同。由于第一参考层和第二参考层都可以提供自旋转移矩，因而可以降低大大地自由层翻转需要的电流，理论上自由层翻转需要的电流可以降低50％，从而可以提高功耗。
在一种可能的实施方式中，MTJ还包括依次层叠设置在自由层远离第一隧穿层一侧的非磁性层和第二钉扎层；第一钉扎层的磁化方向与第二钉扎层的磁化方向相反。由于第一参考层和第二钉扎层都可以提供自旋转移矩，因而可以大大地降低自由层翻转需要的电流，理论上自由层翻转需要的电流可以降低50％，从而可以提高功耗。此外，第二钉扎层、非磁性层和自由层构成自旋阀结构，由于MTJ中形成的自旋阀结构不需要用到第二隧穿层，且在非磁性层的材料为金属的情况下，因而MTJ的整体电阻减小，这样一来，便可以降低读写电流，进一步降低存储器的功耗，并提高了MTJ的耐久度，延长了存储器的寿命。
在一种可能的实施方式中，第二钉扎层为具有垂直磁各向异性的亚铁磁或反铁磁材料，且第二钉扎层在自由层所在的空间产生的静磁场小于自由层的矫顽磁场。由于第一钉扎层在自由层所在的空间产生的静磁场较小，且第二钉扎层在自由层所在的空间产生的静磁场也较小，这样一来，第一钉扎层和第二钉扎层都不会对自由层产生影响，相对于现有技术便可以降低自由层翻转需要的电流，且可以解决MTJ翻转不对称的问题。
在一种可能的实施方式中，第二钉扎层的材料包括稀土过渡金属合金、钇猛合金、铁锰合金或铂锰合金中的一种或多种。此时，通过调整材料组分，便可以使得第二钉扎层在自由层所在的空间产生的静磁场小于自由层的矫顽磁场。
在一种可能的实施方式中，第二钉扎层的材料为非晶材料。由于非晶材料是自体式而非界面式，对生长界面没有要求，因而对粗糙度和应力不敏感，这样一来，便可以解决因粗糙度和应力累积导致的第二钉扎层产生的不稳定。
在一种可能的实施方式中，第一电极位于第一钉扎层远离自由层的一侧，第二电极位于自由层远离第一隧穿层的一侧，且与自由层接触；第二电极复用为自旋轨道力矩提供层。由于一方面，第一参考层提供自旋转移距STT翻转自由层，另一方面，自 旋轨道力矩提供层提供自旋轨道矩SOT翻转自由层。由于自由层同时被自旋转移距STT和自旋轨道矩SOT翻转，因而可以大大地降低自由层翻转需要的电流。
在一种可能的实施方式中，第二电极的材料为重金属单质、重金属合金、拓扑绝缘体或外尔半金属中的一种或多种。在此情况下，第二电极可以复用为自旋轨道力矩提供层。
在一种可能的实施方式中，第一参考层和自由层的材料包括钴铁硼CoFeB合金；第一隧穿层的材料包括氧化镁MgO。
在一种可能的实施方式中，晶体管的栅电极通过字线WL连接字线控制电路，晶体管的源电极连接源极线SL；第一电极通过位线BL连接位线控制电路。此时，字线控制电路可以控制给字线WL提供信号，位线控制电路可以控制给位线BL提供信号。
第二方面，提供一种电子设备。该电子设备包括电路板以及与电路板电连接的存储器，该存储器为上述的存储器。该电子设备具有与前述实施例相同的技术效果，此处不再赘述。
附图说明
图1a为本申请实施例提供的一种存储系统的结构示意图；
图1b为本申请的另一实施例提供的一种存储系统的结构示意图；
图1c为本申请的又一实施例提供的一种存储系统的结构示意图；
图2为本申请实施例提供的一种存储器的结构示意图；
图3a为本申请实施例提供的一种MTJ元件的结构示意图；
图3b为本申请的另一实施例提供的一种MTJ元件的结构示意图；
图4为本申请实施例提供的一种过渡金属比例与稀土过渡金属合金的磁矩的关系图；
图5为本申请实施例提供的一种CoTb合金的厚度与矫顽场的关系图；
图6a为本申请的又一实施例提供的一种MTJ元件的结构示意图；
图6b为本申请的再一实施例提供的一种MTJ元件的结构示意图；
图7为本申请的另一实施例提供的一种MTJ元件的结构示意图；
图8为本申请的又一实施例提供的一种MTJ元件的结构示意图；
图9为本申请的再一实施例提供的一种MTJ元件的结构示意图。
附图标记：
10-存储器；11-存储单元；12-MTJ元件；121-第一电极；122-第二电极；1231-第一钉扎层；1232-第一参考层；1233-第一隧穿层；1234-自由层；1235-第二隧穿层；1236-第二参考层；1237-第二钉扎层；1238-非磁性层。
具体实施方式
下面将结合本申请实施例中的附图，对本申请实施例中的技术方案进行描述，显然，所描述的实施例仅仅是本申请一部分实施例，而不是全部的实施例。
除非另有定义，否则本文所用的所有科技术语都具有与本领域普通技术人员公知的含义相同的含义。
以下，术语“第一”、“第二”等仅用于描述方便，而不能理解为指示或暗示相对重要性或者隐含指明所指示的技术特征的数量。由此，限定有“第一”、“第二” 等的特征可以明示或者隐含地包括一个或者更多个该特征。此外，术语“电连接”可以是直接的电性连接，也可以通过中间媒介间接的电性连接。
需要说明的是，本申请中，“示例性的”或者“例如”等词用于表示作例子、例证或说明。本申请中被描述为“示例性的”或者“例如”的任何实施例或设计方案不应被解释为比其他实施例或设计方案更优选或更具优势。确切而言，使用“示例性的”或者“例如”等词旨在以具体方式呈现相关概念。
本申请提供的技术方案可以应用于采用磁性随机存取存储器的各种存储系统中。例如，本申请提供的技术方案应用于计算机中。又例如，本申请提供的技术方案应用于包括存储器、或者包括处理器和存储器的存储系统中，该处理器可以为中央处理器(central processing unit，CPU)、人工智能(artificial intelligence，AI)处理器、数字信号处理器(digital signal processor)和神经网络处理器等。
图1a为本申请实施例提供的一种存储系统的结构示意图，存储系统可以包括存储装置，该存储装置可以为磁性随机存取存储器。可选的，该存储系统还可以包括CPU、缓存器(cache)和控制器等。
在一种实施例中，如图1a所示，该存储系统包括集成在一起的CPU、缓存器和存储装置。在另一种实施例中，如图1b所示，该存储系统可以为作为独立的存储器，该存储系统包括集成在一起的CPU、缓存器、控制器和存储装置，该存储装置通过该控制器与该缓存器和该CPU相耦合。在又一种实施例中，如图1c所示，该存储系统包括存储装置，以及集成在一起的CPU、缓存器、控制器和动态随机存储器(dynamic random access memory，DRAM)，该存储装置可以作为外部的存储装置与DRAM耦合；其中，该DRAM通过该控制器与该缓存器和该CPU相耦合。图1a、图1b和图1c中所示的各种存储系统中的CPU也可以替换为CPU核(core)。图1a、图1b和图1c中存储装置可以为磁性随机存取存储器。
本申请实施例提供一种磁性随机存取存储器(下文中称为存储器)，如图2所示，该存储器10的结构包括设置于存储器的存储区域内阵列分布的多个存储单元11，存储单元11包括晶体管T和与晶体管T连接的磁隧道结MTJ元件12。存储器10还包括多条平行排列的字线(word line，WL)和多条平行排列的位线(bit line，BL)，且字线WL与位线BL相互交叉，例如，字线WL与位线BL相互垂直。在一些实施例中，存储器10还包括多条平行排列的源极线(source line，SL)，且源极线SL与位线BL平行。其中，晶体管T的栅电极与字线WL电连接，晶体管T的源电极与源极线SL电连接。
在一些实施例中，字线WL还与字线控制电路电连接，通过字线控制电路为字线WL提供高电平信号或低电平信号，以使晶体管T处于导通状态或截止状态。在晶体管T为N型晶体管的情况下，高电平信号控制晶体管T导通，低电平信号控制晶体管T截止。在晶体管T为P型晶体管的情况下，低电平信号控制晶体管T导通，高电平信号控制晶体管T截止。
在一些实施例中，源极线SL接地。
如图3a和图3b所示，MTJ元件12包括第一电极121、第二电极122和位于第一电极121和第二电极122之间的MTJ，第二电极122与晶体管T的漏电极电连接。第 一电极121与位线BL电连接。
在一些实施例中，位线BL还与位线控制电路电连接，通过位线控制电路为位线BL提供信号。
以下提供三个具体的实施例，对MTJ的结构进行示例性介绍。
实施例一
如图3a和图3b所示，MTJ包括依次层叠设置的第一钉扎层1231、第一参考层1232、第一隧穿层1233和自由层1234；其中，第一钉扎层1231为具有磁各向异性的亚铁磁或反铁磁材料，且第一钉扎层1231在自由层1234所在的空间产生的静磁场(即杂散场)小于自由层1234的矫顽磁场(矫顽力)。
此处，可以是自由层1234靠近第一电极121，第一钉扎层1231靠近第二电极122；也可以是自由层1234靠近第二电极122，第一钉扎层1231靠近第一电极121。
应当理解到，第一参考层1232是MTJ中具有固定磁化方向的膜层，第一钉扎层1231和第一参考层(也可以称为被钉扎层)1232之间具有很强的交换耦合作用，第一参考层1232的磁矩方向(也可以称为磁化方向)可以被第一钉扎层1231钉扎在固定的方向上，第一参考层1232的磁矩方向很难被改变，第一参考层1232的磁化方向和第一钉扎层1231的磁化方向相同。此外，第一钉扎层1231用于使第一参考层1232的磁化方向钉扎在固定的方向上，因而第一钉扎层1231的磁化方向应不易改变，即第一钉扎层1231应具有较大的矫顽场。而第一参考层1232和自由层1234之间由于第一隧穿层1233的作用，处于退耦合的状态，因此自由层1234的磁化方向很容易在外加磁场的作用下发生改变，自由层1234的磁化方向与第一参考层1231的磁化方向可以呈平行或反平行状态。
需要说明的是，存储器10在出厂时，需要对存储单元11中各层的磁化方向进行初始化。具体过程为：施加一个较大的外加磁场，使第一钉扎层1231、第一参考层1232和自由层1234的磁化方向相同，以对存储单元11中各层的磁化方向进行初始化。可以理解的是，由于第一钉扎层1231的材料为亚铁磁或反铁磁材料，因而第一钉扎层1231除了具有因外加磁场产生的初始化的磁化方向外，还具有与初始化的磁化方向反平行的磁化方向，但是与初始化的磁化方向反平行的磁化方向的磁场非常弱。以图3a为例，第一钉扎层1231中标示的粗箭头为初始化的磁化方向，细箭头为与初始化的磁化方向反平行的磁化方向。可以理解的是，第一钉扎层1231标示的粗箭头为第一钉扎层1231的磁化方向。
在本申请的一些实施例中，如图3a所示，第一钉扎层1231的磁化方向平行于MTJ中各层的堆叠方向。此时，第一钉扎层1231为具有垂直磁各向异性(perpendicular magnetic anisotropy，PMA)的亚铁磁或反铁磁材料。MTJ中各层的堆叠方向可以由第一钉扎层1231指向自由层1234，也可以由自由层1234指向第一钉扎层1231。以MTJ中各层的堆叠方向为由第一钉扎层1231指向自由层1234的方向为例，在此情况下，可以用图3a中第一钉扎层1231标示的粗箭头表示MTJ中各层的堆叠方向，第一钉扎层1231的磁化方向平行于MTJ中各层的堆叠方向，可以是第一钉扎层1231的磁化方向与MTJ中各层的堆叠方向相同(即第一钉扎层1231的磁化方向为由第一钉扎层1231指向自由层1234的方向)；也可以是第一钉扎层1231的磁化方向与MTJ中各层 的堆叠方向平行且相反(即第一钉扎层1231的磁化方向为由自由层1234指向第一钉扎层1231的方向)。在第一钉扎层1231的磁化方向平行于MTJ中各层的堆叠方向的情况下，由于第一参考层1232的磁化方向与第一钉扎层1231的磁化方向相同，因而第一参考层1232的磁化方向也平行于MTJ中各层的堆叠方向。此时形成的MTJ为具有垂直磁各向异性的MTJ，垂直磁各向异性的MTJ具有写能量低和可微缩性等优点。
在本申请的另一些实施例中，如图3b所示，第一钉扎层1231的磁化方向垂直于MTJ中各层的堆叠方向。在此情况下，第一钉扎层1231的磁化方向可以垂直于MTJ中各层的堆叠方向向左，也可以垂直于MTJ中各层的堆叠方向向右。附图3b以第一钉扎层1231的磁化方向垂直于MTJ中各层的堆叠方向向右为例进行示意。在第一钉扎层1231的磁化方向垂直于MTJ中各层的堆叠方向的情况下，由于第一参考层1232的磁化方向与第一钉扎层1231的磁化方向相同，因而第一参考层1232的磁化方向也垂直于MTJ中各层的堆叠方向。
此处，第一隧穿层1233为非磁性层，第一隧穿层1233的材料例如可以包括氧化镁(MgO)或三氧化二铝(Al 2O 3)中的一种或多种。
此外，第一参考层1232和自由层1234为磁性层，第一参考层1232和自由层1234的材料例如可以包括钴铁硼(CoFeB)合金、钴铁(CoFe)合金或镍铁钴(NiFeCo)合金中的一种或多种。
基于上述存储器10的结构，以下以一个存储单元11为例，介绍存储器10的工作过程。
存储单元11在写入时，晶体管T处于导通状态，当电流方向由自由层1234流向第一参考层1232，即自旋电子从第一参考层1232流向自由层1234，自旋电子通过第一参考层1232时，电流中的电子沿着第一参考层1232的磁化方向被自旋极化，电子的自旋磁矩与第一参考层1232的磁化方向平行，电子穿过第一隧穿层1233到达自由层1234时，自旋电子将自旋矩(也称为自旋角动量，即STT)传递给自由层1234，而受到自旋矩效应的自由层1234，其磁化强度小，因而自由层1234的磁化方向能够根据自旋电流中自旋电子的极化方向自由地发生变化，最终使得自由层1234的磁化方向和第一参考层1232的磁化方向呈平行状态(即自由层1234的磁化方向与第一参考层1232的磁化方向相同)，可以代表写入信息是“0”。
当电流方向由第一参考层1232流向自由层1234，即自旋电子从自由层1234流向第一参考层1232时，自旋电子与第一参考层1232中的磁矩发生交换耦合作用，使自旋平行于第一参考层1232的磁化方向的电子通过，而自旋反平行于第一参考层1232磁化方向的电子被反射，被反射的电子穿过第一隧穿层1233到达自由层1234，并与自由层1234磁矩发生交换耦合作用，使自由层1234的磁化方向向着第一参考层1232磁化方向的反方向转动，最终使得自由层1234的磁化方向与第一参考层1232的磁化方向呈反平行状态(即自由层1234的磁化方向与第一参考层1232的磁化方向相反)，可以代表写入信息是“1”。此处电流方向可以通过位线BL和源极线SL上提供的电压控制，参考图3a，当位线BL提供的电压大于源极线SL提供的电压，电流由自由层1234流向第一参考层1232；当位线BL提供的电压小于源极线SL提供的电压，电流由第一参考层1232流向自由层1234。
存储单元11在读取时，恒定的小电流从位线BL经过MTJ到导通的晶体管T的漏极流出，在MTJ的两端会产生电位差。根据电位差的大小，可以确定MTJ的电阻，即，可以得到自由层1234与第一参考层1232的磁化方向的相对取向关系，进而可以判断存储单元11存储的信息是“0”还是“1”。具体的，MTJ呈现低电阻，自由层1234的磁化方向与第一参考层1232的磁化方向呈平行状态，存储单元11存储的信息为“0”；MTJ呈现高电阻，自由层1234的磁化方向与第一参考层1232的磁化方向呈反平行状态，存储单元11存储的信息为“1”。
应当理解到，存储器10在存储信息和读取信息时，字线控制电路逐行给字线提供选通信号，以使多行存储单元11中的晶体管T逐行导通，进而可以逐行写入信息或读取信息。
基于上述存储单元11的工作原理，本申请实施例提供的存储器10也可以称为自旋转移距磁性随机存取存储器。
应当理解到，第一钉扎层1231在自由层1234所在的空间产生的静磁场与第一钉扎层1231的磁矩有关，第一钉扎层1231的磁矩越小，第一钉扎层1231在自由层1234所在的空间产生的静磁场越小。
由于第一钉扎层1231为具有磁各向异性的亚铁磁或反铁磁材料，因而第一钉扎层1231的周围都会产生静磁场，而自由层1234位于第一钉扎层1231的周围(例如上方)，因此第一钉扎层1231在自由层1234所在的空间会产生磁场，自由层1234所在的空间指的是自由层1234占据的第一钉扎层1231周围的空间范围，此处自由层1234所在的空间与第一钉扎层1231产生的静磁场的范围存在交集，或者，自由层1234所在的空间完全位于第一钉扎层1231产生的静磁场的范围内。
另外，根据经验值，当第一钉扎层1231在自由层1234所在的空间产生的静磁场小于1000奥斯特(Oe)时，第一钉扎层1231在自由层1234所在的空间产生的静磁场小于自由层1234的矫顽磁场。
在一些实施例中，第一钉扎层1231在自由层1234所在的空间产生的静磁场的磁场强度为0，或者约为0，即，第一钉扎层1231不会产生杂散场，或产生的杂散场趋近于0。此时，第一钉扎层1231的磁矩为0，或者约为0。
在一些实施例中，第一钉扎层1231的材料包括稀土过渡金属合金(rare earth-transition metal alloy，RE-TM)、以稀土过渡金属合金为基础的磁性掺杂化合物、钇锰(YMn)合金、铁锰(FeMn)合金或铂锰(PtMn)合金中的一种或多种。
示例性地，稀土过渡金属合金可以为CoTb(钴铽)合金或CoGd(钴钆)合金。
示例性地，以稀土过渡金属合金为基础的磁性掺杂化合物可以是以CoTb合金或CoGd合金为基础的磁性掺杂化合物。
需要说明的是，上述稀土过渡金属合金以及以稀土过渡金属合金为基础的磁性掺杂化合物为具有垂直磁各向异性的亚铁磁材料。
此处，由于第一钉扎层1231的材料为具有磁各向异性的亚铁磁或反铁磁材料，因而可以通过控制材料的组分和厚度来控制材料的磁矩(Ms)，以使第一钉扎层1231的磁矩较小，接近于0，即，使第一钉扎层1231在自由层1234所在的空间产生的静磁场小于自由层1234的矫顽磁场。图4以稀土过渡金属合金为例，示意出了在其它因 素(例如稀土过渡金属合金的生长方式或厚度等)都一定的情况下，稀土过渡金属合金的磁矩与稀土过渡金属合金中过渡金属所占的比例之间的关系。从图4可以看出，稀土过渡金属合金中过渡金属所占的比例发生变化时，稀土过渡金属合金的磁矩也会发生变化。具体的，随着过渡金属所占的比例增加，稀土过渡金属合金的磁矩逐渐减小，当过渡金属所占的比例增加到某一值时，随着过渡金属所占的比例增加，稀土过渡金属合金的磁矩又逐渐增加。根据稀土过渡金属合金的磁矩与稀土过渡金属合金中过渡金属所占的比例之间的关系，调整稀土和过渡金属的比例，便可以使第一钉扎层1231的磁矩接近于0。例如，第一钉扎层1231的材料为CoTb合金，当Co与Tb的原子比为Co：Tb＝80：20时，第一钉扎层1231的磁矩约为0。由于第一钉扎层1231的磁矩非常小，因而第一钉扎层1231在自由层1234所在的空间产生的杂散场就会很小。
此外，还可以通过控制材料组分和厚度来控制材料的矫顽场(Hc)，以使第一钉扎层1231的矫顽场较大。图5以第一钉扎层1231的材料为CoTb合金，且Co与Tb的原子比为Co：Tb＝80：20为例，示意出了CoTb合金的厚度与矫顽场的关系。从图5可以看出，CoTb合金的厚度越大，矫顽场越大。由于第一钉扎层1231的矫顽场较大，因而在外加磁场的作用下，第一钉扎层1231的磁化方向不易改变，且其与第一参考层1232交换耦合，能够达到钉扎第一参考层1232的效果。
现有技术中，MTJ的结构包括依次层叠设置的钉扎层、参考层、隧穿层和自由层，其中，钉扎层主要是由金属层(非铁磁性的，材料例如为Pt)和铁磁层(材料例如为Co或Fe)交替形成的人工反铁磁层，参考层和自由层的材料包括CoFeB合金，隧穿层的材料包括MgO。由于钉扎层主要是由金属层和铁磁层交替形成的人工反铁磁层，因而钉扎层具有较大的杂散场，即在自由层1234所在的空间会产生较大的静磁场，从而导致自由层会产生较大的补偿场，这样一来，提高了自由层翻转需要的电流，且导致了MTJ翻转不对称，即，使自由层的磁化方向向相反的两个方向改变时所需的电流大小不一样。在存储单元11的尺寸较大时，钉扎层产生的杂散场主要还是边缘效应，对自由层翻转的影响较小，在存储单元11的尺寸较小时，以钉扎层的磁化方向平行于MTJ中各层的堆叠方向为例，杂散场基本都作用于平行于MTJ中各层的堆叠方向的方向上，因此在平行于MTJ中各层的堆叠方向的方向上作用场很大，自由层的翻转受到了很大的影响。基于此，由于目前存储器10中存储单元11的尺寸越来越小，因而杂散场的影响越来越大。此外，在高度集成的MTJ阵列中，这个问题会越来越严重。这是因为在高度集成的MTJ阵列中，由于自由层小同时薄，对外磁场非常敏感，对刻蚀的均匀性要求极高，只要刻蚀完后自由层的形状有一定的差别，例如尺寸、位置等，那么杂散场对自由层的影响也是有很大差异的，为了降低该差异，则需要提高电流大小，以保证读写的准确性。然而，提高电流，不仅会提高功率，而且还会严重影响到MTJ的耐久性，MTJ的寿命可能会大大减小。
本申请实施例提供一种存储器10，该存储器10的结构包括设置于存储器的存储区域内阵列分布的多个存储单元11，存储单元11包括晶体管T和与晶体管T连接的磁隧道结MTJ元件12。MTJ元件12包括第一电极121、第二电极122和位于第一电极121和第二电极122之间的MTJ，第二电极122与晶体管T的漏电极电连接。MTJ包括依次层叠设置的第一钉扎层1231、第一参考层1232、第一隧穿层1233和自由层1234； 第一钉扎层1231为具有磁各向异性的亚铁磁或反铁磁材料，且第一钉扎层1231在自由层1234所在的空间产生的静磁场小于自由层1234的矫顽磁场。由于第一钉扎层1231在自由层1234所在的空间产生的静磁场小于自由层1234的矫顽磁场，因此第一钉扎层1231在自由层1234所在的空间产生的静磁场不会影响自由层1234的磁化方向，这样一来，自由层1234不会因为第一钉扎层1231在自由层1234所在的空间产生的静磁场而产生补偿场，相对于现有技术便可以降低自由层1234翻转需要的电流，且可以解决MTJ翻转不对称的问题。此外，由于第一钉扎层1231在自由层1234所在的空间产生的静磁场小于自由层1234的矫顽磁场，第一钉扎层1231在自由层1234所在的空间产生的静磁场不会影响自由层1234的磁化方向,因而无需提高电流来克服杂散场对自由层1234的影响存在的差异，这样一来，便可以利用较小的电流对自由层1234的磁化方向进行翻转，既可以降低功率，又可以提高MTJ的耐久性，提高了MTJ的寿命。
需要说明的是，第一参考层1232在自由层1234所在的空间也会产生静磁场，即杂散场，但是由于第一参考层1232在自由层1234所在的空间产生的静磁场非常小，基本小于自由层1234的矫顽磁场，不会影响自由层1234，因而第一参考层1232在自由层1234所在的空间产生的静磁场可以忽略不考虑。
现有技术中钉扎层为由金属层和铁磁层交替形成的人工反铁磁层，这个膜层结构是111晶向，而隧穿层(材料为MgO)和自由层(材料为CoFeB)退火后的结构为001结构，由于钉扎层与隧穿层、自由层的晶格差异较大，因而应力和粗糙度累积会导致钉扎层不稳定，例如垂直磁向弱。基于此，在本申请的一些实施例中，第一钉扎层1231的材料为非晶材料(amorphous)。
示例的，第一钉扎层1231的材料包括稀土过渡金属合金、以稀土过渡金属合金为基础的磁性掺杂化合物。
本申请实施例中，由于第一钉扎层1231的材料为非晶材料，而非晶材料是自体式而非界面式，对生长界面没有要求，因而对粗糙度和应力不敏感，这样一来，便可以解决因粗糙度和应力累积导致的第一钉扎层1231产生的不稳定。
在一些实施例中，如图6a和图6b所示，第一电极121位于第一钉扎层1231远离自由层1234的一侧，第二电极122位于自由层1234远离第一隧穿层1233的一侧，且与自由层1234接触；第二电极122复用为自旋轨道力矩(spin orbit torque，简称SOT)提供层。
此处，第二电极122的材料例如可以为重金属单质、重金属合金、拓扑绝缘体或外尔半金属中的一种或多种。
示例的，重金属单质可以为铂(Pt)、钽(Ta)、铜(Cu)、铱(Ir)、钌(Ru)或钨(W)中的一种或多种。
示例的，重金属合金可以为铂、钽、铜、铱、钌或钨中的两个或两个以上组成的合金。
示例的，拓扑绝缘体可以为硒化铋(Bi 2Se 3)化合物、碲化锑(Sb 2Te 3)化合物或碲化铋(Bi 2Te 3)化合物中的一种或多种。
示例的，外尔半金属可以为二碲化钨(WTe 2)。
另外，自旋轨道力矩提供层可以是一层，也可以是多层。
自旋轨道力矩提供层翻转自由层1234的原理为流经自旋轨道力矩提供层的电流能够产生自旋流，作用于磁性层(如自由层1234)，产生的自旋轨道矩SOT引发自由层1234磁化翻转，通过在自旋轨道力矩提供层中通入正向或反向电流，带有不同自旋方向的电子作用于磁性层，从而可以实现高阻态(记为“1”)或低阻态(记为“0”)的写入。
在第二电极122复用为自旋轨道力矩提供层的情况下，在一些示例中，如图6a所示，第二电极122与一个晶体管T的漏电极电连接，该晶体管T的栅电极与字线WL电连接，源电极与源极线SL连接。源极线SL可以接地。
在该示例中，MTJ的写入过程为晶体管T导通，位线BL写入电流，一方面，第一参考层1232提供自旋转移距STT翻转自由层1234，另一方面，自旋轨道力矩提供层提供自旋轨道矩SOT翻转自由层1234。由于自由层1234同时被自旋转移距STT和自旋轨道矩SOT翻转，因而可以大大地降低自由层1234翻转需要的电流。MTJ的读取过程与上述读取过程相同，此处不再赘述。
在另一些示例中，如图6b所示，第二电极122分别与两个晶体管(晶体管T1和晶体管T2)的漏电极电连接，晶体管T1的漏电极与第二电极122连接的位置点A和晶体管T2的漏电极与第二电极122连接的位置点B位于第二电极122沿垂直于第二电极122的剖面的两端，晶体管T1的栅电极与字线WL1电连接，源电极与源极线SL1连接，晶体管T2的栅电极与字线WL2电连接，源电极与源极线SL2连接。
由于第二电极122分别与晶体管T1的漏电极和晶体管T2的漏电极电连接，且晶体管T1的漏电极与第二电极122连接的位置点A和晶体管T2的漏电极与第二电极122连接的位置点B位于第二电极122沿垂直于第二电极122的剖面的两端，因而整面自旋轨道力矩提供层都可以提供自旋轨道矩SOT，从而提高了自由层1234的翻转效率，降低了自由层1234翻转需要的电流。
在该示例中，MTJ有两种工作方式，第一种，位线BL写入电流，第一参考层1232提供自旋转移距STT翻转自由层1234，同时，字线WL1提供选通信号，晶体管T1导通，字线WL2提供选通信号，晶体管T2导通，源极线SL1和源极线SL2写入电流，自旋轨道力矩提供层提供自旋轨道矩SOT翻转自由层1234。由于自由层1234同时被自旋转移距STT和自旋轨道矩SOT翻转，因而可以大大地降低自由层1234翻转需要的电流。
第二种，在第一时刻，位线BL写入电流，第一参考层1232提供自旋转移距STT翻转自由层1234，同时，字线WL1提供选通信号，晶体管T1截止，字线WL2提供选通信号，晶体管T2截止，此时，自旋轨道力矩提供层不工作，即不提供自旋轨道矩SOT；在第二时刻，位线BL不写入电流，即电流为0，此时，第一参考层1232不提供自旋转移距STT，字线WL1提供选通信号，晶体管T1导通，字线WL2提供选通信号，晶体管T2导通，源极线SL1和源极线SL2写入电流，自旋轨道力矩提供层提供自旋轨道矩SOT翻转自由层1234；第一时刻和第二时刻交替，即，自旋转移距STT和自旋轨道矩SOT交替翻转自由层1234，从而能够大大减小自由层1234翻转需要的电流。MTJ读取时，晶体管T1和晶体管T2中的一个导通，另一个截止，位线BL写入恒定的小电流，参考上述存储单元11的读取过程，判断存储单元11存储的信息是“0”还是“1”。
第二种工作方式，在第二时刻，由于电流不经过第一隧穿层1233，因而源极线SL1和源极线SL2可以写入较大的电流，而不会击穿第一隧穿层1233，而源极线SL1和源极线SL2写入较大的电流，自旋轨道力矩提供层能够提供较大的自旋轨道矩SOT翻转自由层1234，以提高自由层1234的翻转效率。
实施例二
如图7所示，MTJ包括依次层叠设置的第一钉扎层1231、第一参考层1232、第一隧穿层1233、自由层1234、第二隧穿层1235、第二参考层1236和第二钉扎层1237；其中，第一钉扎层1231和第二钉扎层1237的磁化方向均平行于MTJ中各层的堆叠方向，第一钉扎层1231的磁化方向与第二钉扎层1237的磁化方向相反，且第一隧穿层1233的电阻与第二隧穿层1235的电阻不同。
此处，第一钉扎层1231用于使第一参考层1232的磁化方向钉扎在固定的方向上，第一参考层1232的磁化方向和第一钉扎层1231的磁化方向相同，第二钉扎层1237用于使第二参考层1236的磁化方向钉扎在固定的方向上，第二参考层1236的磁化方向和第二钉扎层1237的磁化方向相同。由于第一钉扎层1231的磁化方向与第二钉扎层1237的磁化方向相反，因而第一参考层1232的磁化方向和第二参考层1236的磁化方向相反。
需要说明的是，存储器10在出厂时，在对存储单元11中各层的磁化方向进行初始化的过程中，为了确保初始化后第一钉扎层1231和第二钉扎层1237的磁化方向相反，因而第一钉扎层1231和第二钉扎层1237的矫顽力不同，例如第一钉扎层1231的矫顽力大于第二钉扎层1237的矫顽力。此处，可以通过调整第一钉扎层1231的厚度调整第一钉扎层1231的矫顽力，通过调整第二钉扎层1237的厚度调整第二钉扎层1237的矫顽力。在一些实施例中，第一参考层1232和第二参考层1236的矫顽力也不同，例如，第一参考层1232的矫顽力大于第二参考层1236的矫顽力(此时第一钉扎层1231的矫顽力大于第二钉扎层1237的矫顽力)。此处，可以通过调整第一参考层1232的厚度调整第一参考层1232的矫顽力，通过调整第二参考层1236的厚度调整第二参考层1236的矫顽力。
对上述存储单元11进行初始化的具体过程为：首先，如图8所示，施加一个较大的外加磁场，使第一钉扎层1231、第一参考层1232、第二钉扎层1237、第二参考层1236和自由层1234的磁化方向相同；然后，如图7所示，施加一个较小的外加磁场，使第二钉扎层1237和第二参考层1236的磁化方向向相反的方向翻转。由于第一钉扎层1231的矫顽力大于第二钉扎层1237的矫顽力，因而施加的较小的外加磁场可以使第二钉扎层1237的磁化方向向相反的方向翻转，但不能使第一钉扎层1231的磁化方向翻转，而第一参考层1232的磁化方向被第一钉扎层1231钉扎在固定的方向上很难改变，因此施加较小的外加磁场后，第一参考层1232的磁化方向不会发生翻转，这样一来，初始化后第一钉扎层1231的磁化方向和第二钉扎层1237的磁化方向相反，第一参考层1232的磁化方向和第二参考层1236的磁化方向相反。
此处，第二隧穿层1235为非磁性层，第二隧穿层1235的材料例如可以包括氧化镁或三氧化二铝中的一种或多种。第一隧穿层1233的材料和第二隧穿层1235的材料可以相同，也可以不相同。
另外，第二参考层1236的材料可以参考上述第一参考层1232的材料，此处不再赘述。第一参考层1232的材料和第二参考层1236的材料可以相同，也可以不相同。
本实施例中，MTJ的写入过程为：当电流由第二钉扎层1237流向第一钉扎层1231，即自旋电子由第一钉扎层1231流向第二钉扎层1237，自旋电子通过第一参考层1232时，电流中的电子沿着第一参考层1232的磁化方向被自旋极化，电子的自旋磁矩与第一参考层1232的磁化方向平行，电子穿过第一隧穿层1233到达自由层1234时，自旋电子将自旋矩，即自旋角动量传递给自由层1234，自由层1234的磁化方向能够根据自旋电流中自旋电子的极化方向自由地发生变化，自由层1234的磁化方向与第一参考层1232的磁化方向平行，自旋电子经过第二隧穿层1235到达第二参考层1236时，由于第二参考层1236的磁化方向与第一参考层1232的磁化方向相反，而电子的自旋磁矩与第一参考层1232的磁化方向平行，因而自旋电子不能通过第二参考层1236，根据动量守恒定律，第二参考层1236将角动量传递给自旋电子，自旋电子被第二参考层1236反射向自由层1234，进一步使自由层1234的磁化方向与第一参考层1232的磁化方向呈平行状态。
当电流由第一钉扎层1231流向第二钉扎层1237，即自旋电子由第二钉扎层1237流向第一钉扎层1231，与上述过程类似，此处不再赘述，最终自由层1234的磁化方向与第二参考层1236的磁化方向平行。
由于第一隧穿层1233和第二隧穿层1235的电阻不同，以第一隧穿层1233的电阻大于第二隧穿层1235的电阻为例，电流由第二钉扎层1237流向第一钉扎层1231，或者电流由第一钉扎层1231流向第二钉扎层1237时，当自由层1234的磁化方向与靠近第一隧穿层1233的第一钉扎层1231的磁化方向相同，此时存储单元呈低阻态，写入信息为“0”；当自由层1234的磁化方向与靠近第一隧穿层1233的第一钉扎层1231的磁化方向相反，此时存储单元呈高阻态，写入信息为“1”。MTJ的读取过程与上述实施例一中MTJ的读取过程类似，可以参考上述实施一中MTJ的读取过程，此处不再赘述。
根据上述MTJ的写入过程可知，第一参考层1232和第二参考层1236都可以提供自旋转移矩，因而可以大大地降低自由层1234翻转需要的电流，理论上自由层1234翻转需要的电流可以降低50％，从而可以提高功耗。
本申请实施例中，由于第一钉扎层1231在自由层1234所在的空间产生的静磁场小于自由层1234的矫顽磁场，因此第一钉扎层1231在自由层1234所在的空间产生的静磁场不会影响自由层1234的磁化方向，这样一来，自由层1234不会因为第一钉扎层1231在自由层1234所在的空间产生的静磁场而产生补偿场，相对于现有技术便可以降低自由层1234翻转需要的电流，且可以解决MTJ翻转不对称的问题。
在一些实施例中，第二钉扎层1237为具有垂直磁各向异性的亚铁磁或反铁磁材料，且第二钉扎层1237在自由层1234所在的空间产生的静磁场小于自由层1234的矫顽磁场。
应当理解到，第二钉扎层1237在自由层1234所在的空间产生的静磁场与第二钉扎层1237的磁矩有关，第二钉扎层1237的磁矩越小，第二钉扎层1237在自由层1234所在的空间产生的静磁场越小。
此处，第二钉扎层1237在自由层1234所在的空间产生的静磁场可以参考上述第一钉扎层1231在自由层1234所在的空间产生的静磁场的解释说明，此处不再赘述。
另外，根据经验值，当第二钉扎层1237在自由层1234所在的空间产生的静磁场小于1000奥斯特(Oe)时，第二钉扎层1237在自由层1234所在的空间产生的静磁场小于自由层1234的矫顽磁场。
在一些实施例中，第二钉扎层1237在自由层1234所在的空间产生的静磁场的磁场强度为0，或者约为0，即，第二钉扎层1237不会产生杂散场，或产生的杂散场趋近于0。此时，第二钉扎层1237的磁矩为0，或者约为0。虽然第一钉扎层1231的磁化方向和第二钉扎层1237的磁化方向相反，第一钉扎层1231在自由层1234所在的空间产生的静磁场和第二钉扎层1237在自由层1234所在的空间产生的静磁场理论上可以相互抵消，但是第一钉扎层1231和第二钉扎层1237在制作时由于工艺波动(例如刻蚀不均，或者溅射薄膜时溅射不均)导致第一钉扎层1231和第二钉扎层1237的厚度不均匀，因而第一钉扎层1231在自由层1234所在的空间产生的静磁场和第二钉扎层1237在自由层1234所在的空间产生的静磁场无法完全抵消。而本申请实施例中，由于第一钉扎层1231在自由层1234所在的空间产生的静磁场小于自由层1234的矫顽磁场，第二钉扎层1237在自由层1234所在的空间产生的静磁场小于自由层1234的矫顽磁场，例如第一钉扎层1231在自由层1234所在的空间产生的静磁场为0(此时第一钉扎层1231的磁矩为0)，第二钉扎层1237在自由层1234所在的空间产生的静磁场为0，(此时第二钉扎层1237的磁矩为0)，因而第一钉扎层1231在自由层1234所在的空间产生的静磁场较小，且第二钉扎层1237在自由层1234所在的空间产生的静磁场也较小，这样一来，第一钉扎层1231和第二钉扎层1237都不会对自由层1234产生影响，相对于现有技术便可以降低自由层1234翻转需要的电流，且可以解决MTJ翻转不对称的问题。
在一些实施例中，第二钉扎层1237的材料包括稀土过渡金属合金、以稀土过渡金属合金为基础的磁性掺杂化合物、钇锰合金、铁锰合金或铂锰合金中的一种或多种。
此外，可以通过控制第二钉扎层1237的材料的组分和厚度来控制第二钉扎层1237的磁矩，以使第二钉扎层1237的磁矩较小，接近于0，即，使第二钉扎层1237在自由层1234所在的空间产生的静磁场小于自由层1234的矫顽磁场。具体可以参考上述实施例，此处不再赘述。
另外，还可以通过控制第二钉扎层1237的材料组分和厚度来控制第二钉扎层1237的矫顽场。
在一些实施例中，第二钉扎层1237的材料为非晶材料。非晶材料例如为稀土过渡金属合金或以稀土过渡金属合金为基础的磁性掺杂化合物。
本申请实施例中，由于第二钉扎层1237的材料为非晶材料，而非晶材料是自体式而非界面式的，对生长界面没有要求，因而对粗糙度和应力不敏感，这样一来，便可以解决因粗糙度和应力累积导致的第二钉扎层1237产生的不稳定。
实施例三
如图9所示，MTJ包括依次层叠设置的第一钉扎层1231、第一参考层1232、第一隧穿层1233、自由层1234、非磁性层1238和第二钉扎层1237；其中，第一钉扎层1231 和第二钉扎层1237的磁化方向均平行于MTJ中各层的堆叠方向，第一钉扎层1231的磁化方向与第二钉扎层1237的磁化方向相反。
此处，第二钉扎层1237、非磁性层1238和自由层1234构成自旋阀(spin valve)结构。
此外，非磁性层1238的材料例如可以为Cu、Ta、Mo(钼)、Al 2O 3、MgO、MgAlO x(氧化镁铝)。
本实施例中，MTJ的写入读取过程与实施例二中MTJ的写入读取过程类似，可以参考上述实施例，此处不再赘述。
本申请实施例中，由于第一钉扎层1231在自由层1234所在的空间产生的静磁场小于自由层1234的矫顽磁场，因此第一钉扎层1231在自由层1234所在的空间产生的静磁场不会影响自由层1234的磁化方向，这样一来，自由层1234不会因为第一钉扎层1231在自由层1234所在的空间产生的静磁场而产生补偿场，相对于现有技术便可以降低自由层1234翻转需要的电流，且可以解决MTJ翻转不对称的问题。在此基础上，第一参考层1232和第二钉扎层1237都可以提供自旋转移矩，因而可以大大地降低自由层1234翻转需要的电流，理论上自由层1234翻转需要的电流可以降低50％，从而可以提高功耗。此外，由于MTJ中形成的spin valve结构不需要用到第二隧穿层1235，且在非磁性层1238的材料为金属的情况下，因而MTJ的整体电阻减小，这样一来，便可以降低读写电流，进一步降低存储器10的功耗，并提高了MTJ的耐久度，延长了存储器10的寿命。
在一些实施例中，第二钉扎层1237为具有垂直磁各向异性的亚铁磁或反铁磁材料，且第二钉扎层1237在自由层1234所在的空间产生的静磁场小于自由层1234的矫顽磁场。
在一些实施例中，第二钉扎层1237的材料为非晶材料。
需要说明的是，本实施例中的第二钉扎层1237与上述实施例二中的第二钉扎层1237相同，可以参考实施二中对第二钉扎层1237的描述以及效果分析，此处不再赘述。
基于此，本申请实施例还提供一种电子设备，该电子设备包括电路板、以及与电路板连接的存储器，该存储器可以为上文所提供的任一种存储器。其中，该电路板可以为印制电路板(printed circuit board，PCB)，当然电路板还可以为柔性电路板(flexible printed circuit board，FPC)等，本实施例对电路板不作限制。
可选的，该电子设备为计算机、手机、平板电脑、可穿戴设备和车载设备等不同类型的用户设备或者终端设备；该电子设备还可以为基站等网络设备。可选的，该电子设备还包括封装基板，该封装基板通过焊球固定于印刷电路板PCB上，该存储器通过焊球固定于封装基板上。需要说明的是，关于电子设备中存储器的相关描述，具体可以参见上述实施例关于存储器的描述，本申请实施例在此不再赘述。
在本申请的另一方面，还提供一种与计算机一起使用的非瞬时性计算机可读存储介质，该计算机具有用于创建集成电路的软件，该计算机可读存储介质上存储有一个或多个计算机可读数据结构，一个或多个计算机可读数据结构具有用于制造上文所提供的任意一个图示所提供的存储器的光掩膜数据。
以上所述，仅为本申请的具体实施方式，但本申请的保护范围并不局限于此，任何熟悉本技术领域的技术人员在本申请揭露的技术范围内，可轻易想到变化或替换，都应涵盖在本申请的保护范围之内。因此，本申请的保护范围应以所述权利要求的保护范围为准。

Claims (14)

  1. 一种存储器，其特征在于，包括设置于所述存储器的存储区域内阵列分布的多个存储单元，所述存储单元包括晶体管和与所述晶体管连接的磁隧道结MTJ元件；
    所述MTJ元件包括第一电极、第二电极和位于所述第一电极和所述第二电极之间的MTJ，所述第二电极与所述晶体管的漏电极电连接；
    所述MTJ包括依次层叠设置的第一钉扎层、第一参考层、第一隧穿层和自由层；
    其中，所述第一钉扎层为具有磁各向异性的亚铁磁或反铁磁材料，且所述第一钉扎层在所述自由层所在的空间产生的静磁场小于所述自由层的矫顽磁场。
  2. 根据权利要求1所述的存储器，其特征在于，所述第一钉扎层的磁化方向平行于所述MTJ中各层的堆叠方向。
  3. 根据权利要求1所述的存储器，其特征在于，所述第一钉扎层的材料包括稀土过渡金属合金、钇锰合金、铁锰合金或铂锰合金中的一种或多种。
  4. 根据权利要求1所述的存储器，其特征在于，所述第一钉扎层的材料为非晶材料。
  5. 根据权利要求2所述的存储器，其特征在于，所述MTJ还包括依次层叠设置在所述自由层远离所述第一隧穿层一侧的第二隧穿层、第二参考层和第二钉扎层；
    其中，所述第一钉扎层的磁化方向与所述第二钉扎层的磁化方向相反，所述第一隧穿层的电阻与所述第二隧穿层的电阻不同。
  6. 根据权利要求2所述的存储器，其特征在于，所述MTJ还包括依次层叠设置在所述自由层远离所述第一隧穿层一侧的非磁性层和第二钉扎层；
    其中，所述第一钉扎层的磁化方向与所述第二钉扎层的磁化方向相反。
  7. 根据权利要求5或6所述的存储器，其特征在于，所述第二钉扎层为具有垂直磁各向异性的亚铁磁或反铁磁材料，且所述第二钉扎层在所述自由层所在的空间产生的静磁场小于所述自由层的矫顽磁场。
  8. 根据权利要求7所述的存储器，其特征在于，所述第二钉扎层的材料包括稀土过渡金属合金、钇猛合金、铁锰合金或铂锰合金中的一种或多种。
  9. 根据权利要求5-8任一项所述的存储器，其特征在于，所述第二钉扎层的材料为非晶材料。
  10. 根据权利要求1所述的存储器，其特征在于，所述第一电极位于所述第一钉扎层远离所述自由层的一侧，所述第二电极位于所述自由层远离所述第一隧穿层的一侧，且与所述自由层接触；
    所述第二电极复用为自旋轨道力矩提供层。
  11. 根据权利要求10所述的存储器，其特征在于，所述第二电极的材料为重金属单质、重金属合金、拓扑绝缘体或外尔半金属中的一种或多种。
  12. 根据权利要求1所述的存储器，其特征在于，所述第一参考层和所述自由层的材料包括钴铁硼CoFeB合金；
    所述第一隧穿层的材料包括氧化镁MgO。
  13. 根据权利要求1所述的存储器，其特征在于，所述晶体管的栅电极通过字线WL连接字线控制电路，所述晶体管的源电极连接源极线SL；所述第一电极通过位线 BL连接位线控制电路。
  14. 一种电子设备，包括电路板以及与所述电路板电连接的存储器，其特征在于，所述存储器为如权利要求1-13任一项所述的存储器。
PCT/CN2020/121680 2020-10-16 2020-10-16 一种存储器及电子设备 WO2022077499A1 (zh)

Priority Applications (2)

Application Number Priority Date Filing Date Title
CN202080105271.7A CN116250040B (zh) 2020-10-16 2020-10-16 一种存储器及电子设备
PCT/CN2020/121680 WO2022077499A1 (zh) 2020-10-16 2020-10-16 一种存储器及电子设备

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/CN2020/121680 WO2022077499A1 (zh) 2020-10-16 2020-10-16 一种存储器及电子设备

Publications (1)

Publication Number Publication Date
WO2022077499A1 true WO2022077499A1 (zh) 2022-04-21

Family

ID=81208908

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2020/121680 WO2022077499A1 (zh) 2020-10-16 2020-10-16 一种存储器及电子设备

Country Status (2)

Country Link
CN (1) CN116250040B (zh)
WO (1) WO2022077499A1 (zh)

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20040179395A1 (en) * 2003-03-14 2004-09-16 David Tsang Magnetic tunneling junction cell array with shared reference layer for MRAM applications
US20130240963A1 (en) * 2012-03-16 2013-09-19 Headway Technologies, Inc. STT-MRAM Reference Layer Having Substantially Reduced Stray Field and Consisting of a Single Magnetic Domain
CN109690675A (zh) * 2016-06-28 2019-04-26 赢世通股份有限公司 一种可应用于磁电隧道结的新型字线脉冲写入方法
CN109935254A (zh) * 2017-12-15 2019-06-25 中电海康集团有限公司 写操作方法、电存储器件、装置及存储介质

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9929211B2 (en) * 2008-09-24 2018-03-27 Qualcomm Incorporated Reducing spin pumping induced damping of a free layer of a memory device
US7944738B2 (en) * 2008-11-05 2011-05-17 Micron Technology, Inc. Spin torque transfer cell structure utilizing field-induced antiferromagnetic or ferromagnetic coupling
US20140252438A1 (en) * 2013-03-10 2014-09-11 Alexander Mikhailovich Shukh Three-Dimensional Magnetic Random Access Memory With High Speed Writing
CN104393169B (zh) * 2014-10-10 2017-01-25 北京航空航天大学 一种无需外部磁场的自旋轨道动量矩磁存储器
CN110931633B (zh) * 2019-11-15 2021-08-27 北京航空航天大学 磁隧道结存储单元及存储器

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20040179395A1 (en) * 2003-03-14 2004-09-16 David Tsang Magnetic tunneling junction cell array with shared reference layer for MRAM applications
US20130240963A1 (en) * 2012-03-16 2013-09-19 Headway Technologies, Inc. STT-MRAM Reference Layer Having Substantially Reduced Stray Field and Consisting of a Single Magnetic Domain
CN109690675A (zh) * 2016-06-28 2019-04-26 赢世通股份有限公司 一种可应用于磁电隧道结的新型字线脉冲写入方法
CN109935254A (zh) * 2017-12-15 2019-06-25 中电海康集团有限公司 写操作方法、电存储器件、装置及存储介质

Also Published As

Publication number Publication date
CN116250040B (zh) 2024-09-06
CN116250040A (zh) 2023-06-09

Similar Documents

Publication Publication Date Title
US8670271B2 (en) Magnetic stack having assist layers
US9608039B1 (en) Magnetic junctions programmable using spin-orbit interaction torque in the absence of an external magnetic field
US7307876B2 (en) High speed low power annular magnetic devices based on current induced spin-momentum transfer
US6958927B1 (en) Magnetic element utilizing spin-transfer and half-metals and an MRAM device using the magnetic element
US6970376B1 (en) Magnetic random access memory and method of writing data in magnetic random access memory
WO2020166722A1 (ja) スピントロニクス素子及び磁気メモリ装置
CN110660420A (zh) Mram存储单元
TWI710150B (zh) 具延長之自由層的磁性接面及提供其的方法及磁性記憶體
US7245524B2 (en) Magnetic memory device and write method of magnetic memory device
US20140301135A1 (en) Mram having novelself-referenced read method
US20210074910A1 (en) Magnetoresistive effect element and magnetic memory
US11316100B2 (en) Hybrid perpendicular and in-plane STT-MRAM
US10290338B2 (en) Tilted synthetic antiferromagnet polarizer/reference layer for STT-MRAM bits
US20210005808A1 (en) Magnetoresistance effect element and magnetic memory
WO2022077499A1 (zh) 一种存储器及电子设备
WO2023207700A1 (zh) 存储器及电子设备
US20230298648A1 (en) Memory and electronic device
EP4243099A1 (en) Memory and electronic device
US20240321333A1 (en) Magnetic tunneling junction device capable of magnetic switching without external magnetic field and memory device including the same
CN117202667A (zh) 存储器及其制造方法和电子设备
KR20240143574A (ko) 외부 자기장 없이 자화 반전이 가능한 자기터널접합 소자 및 자기터널접합 소자를 포함하는 메모리 장치
CN115443548A (zh) 一种磁性隧道结及存储单元
CN113937127A (zh) 一种存储单元及存储器
CN116741217A (zh) 磁性随机存储单元、读写方法以及存储器

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 20957277

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 20957277

Country of ref document: EP

Kind code of ref document: A1