WO2022205235A1

WO2022205235A1 - Memory and electronic device

Info

Publication number: WO2022205235A1
Application number: PCT/CN2021/084763
Authority: WO
Inventors: 秦青; 周雪; 刘熹
Original assignee: 华为技术有限公司
Priority date: 2021-03-31
Filing date: 2021-03-31
Publication date: 2022-10-06
Also published as: CN116711477A

Abstract

Embodiments of the present application provide a memory and an electronic device, which relate to the technical field of memories, and can solve the problems of a rare earth-transition metal alloy having poor thermal stability and a pinning layer easily losing the perpendicular magnetic anisotropy thereof. The memory comprises a plurality of memory cells arranged in an array, the memory cells comprising transistors and magnetic tunnel junction (MTJ) elements electrically connected to the transistors. The MTJ element comprises a first electrode, a second electrode, and an MTJ disposed between the first electrode and the second electrode. The MTJ comprises a first fixing layer, a first tunneling layer, and a free layer which are stacked in sequence. The material of the first fixing layer comprises a first rare earth-transition metal alloy and a first doping element doped in the first rare earth-transition metal alloy.

Description

A memory and electronic equipment

technical field

The present application relates to the field of memory technologies, and in particular, to a memory and an electronic device.

Background technique

Magnetic random access memory (MRAM) is a new type of non-volatile memory. Among them, the spin transfer torque magnetic random access memory (STT MRAM) in the magnetic random access memory has fast speed, low power consumption, COMS (complementary metal-oxide-semiconductor, complementary It has received extensive attention due to its advantages such as good compatibility and good compatibility.

The read-write function of the spin-shift magnetic random access memory is realized by the storage unit in the spin-shift magnetic random access memory. As shown in FIG. 1, the structure of the memory cell mainly includes a magnetic tunneling junction (MTJ) element and a transistor T. The MTJ element includes a first electrode (not shown in An MTJ between an electrode and a second electrode, wherein the first electrode is electrically connected to the bit line, the second electrode is electrically connected to the drain of the transistor, the gate of the transistor T is electrically connected to the word line, and the source electrode is electrically connected to the source line. connect. As shown in FIG. 2 , the MTJ includes a pinning layer, a reference layer, a tunneling layer and a free layer that are stacked in sequence.

At present, the material of the pinning layer is usually composed of rare earth transition metal alloy (RE-TM). Since the rare earth transition metal alloy itself has perpendicular magnetic anisotropy (PMA), the pinned layer can have perpendicular magnetic anisotropy. The reason why rare earth transition metal alloys have perpendicular magnetic anisotropy is that atoms of rare earth elements and atoms of transition metal elements in the rare earth transition metal alloy have specific relative positions.

However, due to the poor thermal stability of rare earth transition metal alloys, the atoms of rare earth elements and transition metal elements in the rare earth transition metal alloy will diffuse after annealing at high temperature or under high temperature working conditions, resulting in the easy loss of the pinning layer. Perpendicular magnetic anisotropy, which in turn leads to MTJ failure.

SUMMARY OF THE INVENTION

The embodiments of the present application provide a memory and an electronic device, which can solve the problems of poor thermal stability of rare earth transition metal alloys and easy loss of perpendicular magnetic anisotropy of the pinning layer.

To achieve the above object, the application adopts the following technical solutions:

In a first aspect, a memory is provided, the memory includes a plurality of memory cells distributed in an array, the memory cells include a transistor and a magnetic tunnel junction MTJ element electrically connected to the transistor; the MTJ element includes a first electrode, a second electrode and a An MTJ between an electrode and a second electrode; the MTJ includes a first pinned layer, a first tunneling layer and a free layer that are stacked in sequence; wherein the material of the first pinned layer includes a first rare earth transition metal alloy and a a first dopant element in the first rare earth transition metal alloy. Since the material of the first pinned layer includes the first rare earth transition metal alloy and the first doping element doped in the first rare earth transition metal alloy, and the first rare earth transition metal alloy itself has strong perpendicular magnetic anisotropy, Therefore, the first pinned layer can have perpendicular magnetic anisotropy, that is, the first pinned layer has a fixed magnetization direction. On this basis, in addition to the first rare earth transition metal alloy, the material of the first fixed layer also includes a first doping element, and the first doping element can form a barrier, which can block the rare earth in the first rare earth transition metal alloy. The diffusion of atoms of elements and atoms of transition metal elements, so the relative positions of atoms of rare earth elements and atoms of transition metal elements in the first rare earth transition metal alloy will not shift after high temperature annealing or under high temperature working conditions, Or the offset is smaller, so that the thermal stability of the first rare earth transition metal alloy can be improved, that is, the thermal stability of the first pinned layer can be improved. In this way, the first pinned layer still has perpendicular magnetic anisotropy after high temperature annealing or under high temperature working conditions.

In addition, in this embodiment, since the material of the first pinned layer includes the first rare earth transition metal alloy and the first doping element doped in the first rare earth transition metal alloy, the material of the first pinned layer is a Ferromagnetic amorphous material. Amorphous materials are self-contained rather than interfacial, and there is no requirement for the growth interface, so there will be no problems of roughness accumulation and stress accumulation, which will not lead to MTJ failure.

In a possible embodiment, the atomic radius of the rare earth element and the atomic radius of the transition metal element in the first rare earth transition metal alloy are both larger than the atomic radius of the first doping element. Since the atomic radius of the first doping element is smaller than the atomic radius of the rare earth element in the first rare earth transition metal alloy and smaller than the atomic radius of the transition metal element, it can be avoided that the first doping element is doped in the first rare earth transition metal alloy After neutralization, the specific relative positions between the atoms of the rare earth element and the atoms of the transition metal element in the first rare earth transition metal alloy are affected, so that the perpendicular magnetic anisotropy of the first pinned layer can be prevented from weakening or disappearing.

In a possible embodiment, the atomic radius of the first doping element ranges from 53pm to 125pm. When the atomic radius of the first doping element is in the range of 53pm to 125pm, it can be avoided that the atomic radius of the first doping element is too large, resulting in the doping of the first doping element in the first rare earth transition metal alloy, changing the The relative position between atoms of rare earth elements and atoms of transition metal elements, resulting in the weakening or disappearance of the perpendicular magnetic anisotropy of the first pinned layer; it can also be avoided that the atomic radius of the first doping element is too small, resulting in the first The doping element does not function to block the diffusion of atoms of rare earth elements and atoms of transition metal elements.

In a possible embodiment, the first doping element includes one or more of boron, carbon, and silicon. After doping one or more atoms of boron, carbon and silicon, the diffusion of the atoms of rare earth elements and the atoms of transition metal elements in the first rare earth transition metal alloy can be blocked without changing the atoms and transition of rare earth elements. The relative positions of atoms of a metal element. In addition, doping one or more atoms of boron, carbon, and silicon will not affect the performance of the MTJ.

In a possible implementation manner, the ratio of the volume of the first doping element to the sum of the volume of the first rare earth transition metal alloy and the first doping element is in the range of (0, 50%). If the amount of the first doping element doped in the material is too large, the amount of the first rare earth transition metal alloy will be reduced, which may affect the perpendicular magnetic anisotropy of the first pinned layer, thus making the first rare earth transition metal alloy less. The ratio of the volume of a doping element to the sum of the volume of the first rare earth transition metal alloy and the first doping element is in the range of (0, 50%), which can ensure that the first pinned layer has strong perpendicular magnetic anisotropy.

In a possible embodiment, the rare earth elements in the first rare earth transition metal alloy include one or more of terbium, gadolinium, dysprosium, and cerium.

In a possible embodiment, the transition metal element in the first rare earth transition metal alloy includes one or more of cobalt, iron, and nickel.

In a possible implementation manner, the first fixed layer is a first reference layer. When the first fixed layer is the first reference layer, the first pinned layer may or may not be provided. When the first pinned layer is provided, the first pinned layer may be an SAF structure. Alternatively, the first pinned layer is a first pinned layer, and the MTJ further includes a first reference layer disposed between the first pinned layer and the first tunneling layer. When the first pinned layer is the first pinned layer, since the first pinned layer can be set to a single-layer structure, the first pinned layer provided in this embodiment adopts the SAF structure compared to the first pinned layer in the related art. The thickness of the layers is greatly reduced, thereby reducing the thickness of the MTJ, thus reducing the integration difficulty of the MTJ array and increasing the density of the MRAM.

In a possible implementation, the second electrode is electrically connected to the source or drain of the transistor; the free layer is close to the second electrode relative to the first fixed layer; or the first fixed layer is close to the second electrode relative to the free layer . Since the material of the first pinned layer is an amorphous material with ferrimagnetic properties, the arrangement of the first pinned layer on the upper layer will not cause stress accumulation or accumulation of roughness. Therefore, when the MTJ is fabricated, the free layer can be relatively The layer is close to the second electrode, and the first pinned layer can also be made close to the second electrode relative to the free layer.

In a possible implementation, the second electrode is electrically connected to the source or drain of the transistor; the free layer is in contact with the second electrode; the second electrode is multiplexed as a spin-orbit torque providing layer. When the second electrode is multiplexed as the spin-orbit torque supply layer, when the MTJ writes the stored information, the transistor T is turned on, and the bit line writes current. On the one hand, the first fixed layer provides the spin shift distance STT and flips the free layer. , on the other hand, the spin-orbit moment-providing layer provides spin-orbit moment SOT to flip 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.

In a possible implementation manner, the MTJ further includes a second tunneling layer and a second pinned layer that are sequentially stacked and disposed on the side of the free layer away from the first tunneling layer; wherein the magnetization direction of the first pinned layer is the same as that of the second pinned layer. The magnetization directions of the pinned layers are opposite, and the resistance of the first tunneling layer is different from that of the second tunneling layer. Since both the first pinned layer and the second pinned 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 reducing power consumption.

In a possible embodiment, the material of the second pinned layer includes a second rare earth transition metal alloy and a second doping element doped in the second rare earth transition metal alloy. Since the material of the second pinned layer includes the second rare earth transition metal alloy and the second doping element, and the second rare earth transition metal itself has strong perpendicular magnetic anisotropy, the second pinned layer can have perpendicular magnetic anisotropy Anisotropy, that is, the second pinned layer has a fixed magnetization direction. On this basis, the material of the second fixed layer includes a second doping element in addition to the second rare earth transition metal alloy, and the second doping element can form a barrier, which can block the rare earth in the second rare earth transition metal alloy. The diffusion of atoms of elements and atoms of transition metal elements, so the relative positions of atoms of rare earth elements and atoms of transition metal elements in the second rare earth transition metal alloy will not shift after high temperature annealing or under high temperature working conditions, Or the offset is smaller, so that the thermal stability of the second rare earth transition metal alloy can be improved, that is, the thermal stability of the second pinned layer can be improved. In this way, the second pinned layer still has perpendicular magnetic anisotropy after high temperature annealing or under high temperature working conditions.

In addition, in this embodiment, since the material of the second pinned layer includes the second rare earth transition metal alloy and the second doping element doped in the second rare earth transition metal alloy, the material of the second pinned layer is a Ferromagnetic amorphous material. Amorphous materials are self-contained rather than interfacial, and there is no requirement for the growth interface, so there will be no problems of roughness accumulation and stress accumulation, which will not lead to MTJ failure.

In a possible embodiment, the atomic radius of the rare earth element and the atomic radius of the transition metal element in the second rare earth transition metal alloy are both larger than the atomic radius of the second doping element. Since the atomic radius of the second doping element is smaller than the atomic radius of the rare earth element in the second rare earth transition metal alloy and smaller than the atomic radius of the transition metal element, it can be avoided that the second doping element is doped in the second rare earth transition metal alloy After neutralization, the specific relative positions between the atoms of the rare earth element and the atoms of the transition metal element in the second rare earth transition metal alloy are affected, so that the weakening or disappearance of the perpendicular magnetic anisotropy of the second pinned layer can be avoided.

In a possible embodiment, the atomic radius of the second doping element ranges from 53pm to 125pm. When the atomic radius of the second doping element is in the range of 53pm to 125pm, it can be avoided that the atomic radius of the second doping element is too large, resulting in the doping of the second doping element in the second rare earth transition metal alloy, changing the The relative position between atoms of rare earth elements and atoms of transition metal elements, resulting in the weakening or disappearance of the perpendicular magnetic anisotropy of the second pinned layer; it can also be avoided that the atomic radius of the second doping element is too small, resulting in the second The doping element does not function to block the diffusion of atoms of rare earth elements and atoms of transition metal elements.

In a possible embodiment, the second doping element includes one or more of boron, carbon, and silicon. After doping one or more atoms of boron, carbon and silicon, it can not only block the diffusion of the atoms of rare earth elements and the atoms of transition metal elements in the second rare earth transition metal alloy, but will not change the atoms and transition of rare earth elements. The relative positions of atoms of a metal element. In addition, doping one or more atoms of boron, carbon, and silicon will not affect the performance of the MTJ.

In a possible embodiment, the proportion of the volume of the second doping element to the sum of the volume of the second rare earth transition metal alloy and the second doping element is in the range of (0, 50%). If the amount of the second doping element doped in the material is too large, the amount of the second rare earth transition metal alloy will be reduced, which may affect the perpendicular magnetic anisotropy of the second pinned layer, thus making the first The ratio of the volume of the second doping element to the sum of the volume of the second rare earth transition metal alloy and the second doping element is in the range of (0, 50%), which can ensure that the second pinned layer has strong perpendicular magnetic anisotropy.

In a possible implementation manner, the second pinned layer is a second pinned layer, and the MTJ further includes a second reference layer disposed between the second tunneling layer and the second pinned layer. When the second pinned layer is the second pinned layer, since the second pinned layer can be set to a single-layer structure, compared with the SAF structure used for the pinned layer in the related art, the second pinned layer provided in this embodiment has a The thickness is greatly reduced, thereby reducing the thickness of the MTJ, thus reducing the integration difficulty of the MTJ array and increasing the density of the MRAM.

In a possible implementation manner, the second fixed layer is a second reference layer. In this case, the second pinning layer may or may not be provided.

In a possible implementation manner, the MTJ further includes a second pinning layer disposed on a side of the second reference layer away from the free layer; the second pinning layer includes first pinning layers disposed in sequence along the stacking direction of the layers in the MTJ A composite layer, a non-magnetic layer and a second composite layer; wherein the first composite layer and the second composite layer both include ferromagnetic layers and metal layers alternately stacked; the magnetization direction of the first composite layer and the magnetization of the second composite layer In the opposite direction. Here, the second pinning layer adopts the SAF structure.

In a possible implementation, the second electrode is electrically connected to the source or drain of the transistor; the second pinned layer is close to the second electrode relative to the free layer. Since the second pinned layer includes the first composite layer, the non-magnetic layer and the second composite layer that are stacked in sequence, the second pinned layer is close to the second electrode relative to the free layer, that is, the second pinned layer is disposed in the lower layer, In this way, the accumulation of roughness and the accumulation of stress caused by the disposition of the second pinning layer on the upper layer can be avoided.

In a possible implementation manner, the MTJ further includes a lattice conversion layer disposed between the second pinning layer and the second tunneling layer, and the material of the lattice conversion layer is an amorphous material. Since the material of the lattice conversion layer is an amorphous material, and the amorphous material has no fixed crystal orientation, growing other layers such as the second reference layer on the lattice conversion layer can avoid the growth difficulties caused by the lattice difference and the roughness. Accumulation, stress accumulation, etc.

In a second aspect, an electronic device is provided, the electronic device includes a circuit board and a memory electrically connected to the circuit board, where the memory is the memory provided in the first aspect.

Description of drawings

1 is a schematic structural diagram of a storage unit provided by the prior art;

Fig. 2 is the structural representation of a kind of MTJ that the prior art provides;

3 is a schematic structural diagram of an electronic device according to an embodiment of the present application;

4 is a schematic structural diagram of an electronic device according to another embodiment of the present application;

5 is a schematic structural diagram of a magnetic random access memory according to an embodiment of the present application;

6 is a schematic structural diagram of an MTJ element provided by an embodiment of the present application;

7 is a graph showing the relationship between the magnetic moment and the coercive force of a pinning layer provided by the prior art and the volume ratio of Tb in the CoTb alloy;

8 is a schematic diagram of the relative positions of Co atoms and Tb atoms in a CoTb alloy provided by the prior art;

9a is a schematic structural diagram of an MTJ element provided by another embodiment of the present application;

9b is a schematic structural diagram of an MTJ element provided by another embodiment of the present application;

10 is a graph of the relationship between the magnetic moment and coercive force of a first pinning layer and the volume ratio of Tb, respectively, according to an embodiment of the application;

11 is a schematic diagram of the relative positions of a Co atom, a Tb atom and a B atom provided in an embodiment of the application;

12 is a schematic structural diagram of a MTJ provided by the related art;

13 is a schematic structural diagram of an MTJ element provided by another embodiment of the present application;

14 is a schematic structural diagram of an MTJ element provided by another embodiment of the present application;

15 is a schematic structural diagram of an MTJ element provided by another embodiment of the present application;

16 is a schematic structural diagram of a first composite layer or a second composite layer provided by an embodiment of the application;

17a is a schematic structural diagram of an MTJ element provided by another embodiment of the present application;

17b is a schematic structural diagram of an MTJ element provided by another embodiment of the present application;

18 is a schematic structural diagram of an MTJ element provided by another embodiment of the application;

19 is a schematic structural diagram of an MTJ element provided by another embodiment of the application;

20 is a schematic structural diagram of an MTJ element provided by another embodiment of the present application;

FIG. 21 is a schematic structural diagram of an MTJ element provided by another embodiment of the present application.

Reference number:

01-electronic equipment; 10-magnetic random access memory (memory); 10A-storage unit; 11-storage device; 12-processor; 13-input device; 14-output device; 15-middle frame; 16-rear case ;17-display screen;100-MTJ element;101-first electrode;102-second electrode;111-external memory;112-internal memory;121-calculator;122-controller;150-carrying board;151- frame; 1030-first fixed layer; 1031-first pinning layer; 1031a-first composite layer; 1031b-non-magnetic layer; 1031c-second composite layer; 1032-first reference layer; 1033-first tunneling 1034 - free layer; 1035 - capping layer; 1036 - second tunneling layer; 1037 - second reference layer; 1038 - second pinning layer; 1039 - lattice conversion layer; 1040 - second pinned layer.

Detailed ways

The technical solutions in the embodiments of the present application will be described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments.

Hereinafter, the terms "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. In the description of this application, unless stated otherwise, "plurality" means two or more.

In the embodiments of the present application, unless otherwise expressly specified and limited, the term "electrical connection" may be a direct electrical connection or an indirect electrical connection through an intermediate medium.

In the embodiments of the present application, words such as "exemplary" or "for example" are used to represent examples, illustrations or illustrations. Any embodiments or designs described in the embodiments of the present application as "exemplary" or "such as" should not be construed as preferred or advantageous over other embodiments or designs. Rather, use of words such as "exemplary" or "such as" is intended to present the related concepts in a specific manner.

In the embodiment of the present application, "and/or", which describes the association relationship of the associated objects, indicates that there can be three kinds of relationships, for example, A and/or B can indicate that A exists alone, A and B exist at the same time, and they exist independently The case of B, where A and B can be singular or plural. The character "/" generally indicates that the associated objects are an "or" relationship.

In the embodiments of the present application, direction indications such as up, down, left, right, front and rear, etc. used to explain the structures and movements of different components in the present application are relative. These indications are appropriate when the parts are in the positions shown in the figures. However, if the description of the element location changes, these directional indications will also change accordingly.

An embodiment of the present application provides an electronic device, and the electronic device may be, for example, a mobile phone (mobile phone), a tablet computer (pad), a personal digital assistant (PDA), a TV, and a smart wearable product (for example, a smart watch). , smart bracelet), virtual reality (virtual reality, VR) terminal equipment, augmented reality (augmented reality, AR) terminal equipment, charging small household appliances (such as soybean milk machine, sweeping robot), drones, radar, aerospace equipment and different types of user equipment or terminal equipment such as in-vehicle equipment; the electronic equipment may also be network equipment such as base stations. The specific form of the electronic device is not particularly limited in the embodiments of the present application.

FIG. 3 is a schematic structural diagram of an electronic device exemplarily provided by an embodiment of the present application. As shown in FIG. 3 , the electronic device 01 includes: a storage device 11 , a processor 12 , an input device 13 , an output device 14 and other components. Those skilled in the art can understand that the structure of the electronic device shown in FIG. 3 does not constitute a limitation on the electronic device 01, and the electronic device 01 may include more or less components than those shown in FIG. 3 , Either some of the components shown in FIG. 3 may be combined, or the components may be arranged differently than those shown in FIG. 3 .

The storage device 11 is used to store software programs and modules. The storage device 11 mainly includes a stored program area and a stored data area, wherein the stored program area can store the operating system, the application program required for at least one function (such as a sound playback function, an image playback function, etc.), etc.; Data (such as audio data, image data, phone book, etc.) created by the use of electronic equipment, etc. Further, the storage device 11 includes an external memory 111 and an internal memory 112 . Data stored in the external memory 111 and the internal memory 112 can be transferred to each other. The external storage 111 includes, for example, a hard disk, a U disk, a floppy disk, and the like. The internal memory 112 includes, for example, random access memory, read-only memory, and the like. The random access memory may be, for example, a magnetic random access memory, a ferroelectric random access memory, or the like.

The processor 12 is the control center of the electronic device 01, using various interfaces and lines to connect various parts of the entire electronic device 01, by running or executing the software programs and/or modules stored in the storage device 11, and calling the stored in the storage device 11. The data in the device 11 executes various functions of the electronic device 01 and processes data, so as to monitor the electronic device 01 as a whole. Optionally, the processor 12 may include one or more processing units. For example, the processor 12 may include an application processor (AP), a modem processor, a graphics processor (graphics processing unit, GPU), an image signal processor (ISP), a flight controller, Video codec, digital signal processor (digital signal processor, DSP), baseband processor, and/or neural-network processing unit (neural-network processing unit, NPU), etc. Wherein, different processing units may be independent devices, or may be integrated in one or more processors. For example, the processor 12 may integrate an application processor and a modem processor, wherein the application processor mainly handles the operating system, user interface and application programs, and the like, and the modem processor mainly handles wireless communication. It can be understood that the above-mentioned modulation and demodulation processor may not be integrated into the processor 12 . The above-mentioned application processor may be, for example, a central processing unit (central processing unit, CPU). In FIG. 3 , the processor 12 is taken as an example of a CPU, and the CPU may include an arithmetic unit 121 and a controller 122 . The arithmetic unit 121 acquires the data stored in the internal memory 112 and processes the data stored in the internal memory 112 , and the processed result is usually sent back to the internal memory 112 . The controller 122 can control the arithmetic unit 121 to process data, and the controller 122 can also control the external memory device 111 and the internal memory 112 to store or read data.

The input device 13 is used for receiving input numerical or character information, and generating key signal input related to user setting and function control of the electronic device. By way of example, the input device 13 may include a touch screen and other input devices. A touch screen, also known as a touch panel, collects the user's touch operations on or near the touch screen (such as the user's operations on or near the touch screen with a finger, a stylus, or any suitable object or accessory), and performs pre-set operations on or near the touch screen. program to drive the corresponding connection device. Optionally, the touch screen may include two parts, a touch detection device and a touch controller. Among them, the touch detection device detects the user's touch orientation, detects the signal brought by the touch operation, and transmits the signal to the touch controller; the touch controller receives the touch information from the touch detection device, converts it into contact coordinates, and then sends it to the touch controller. To the processor 12, and can receive commands from the processor 12 and execute them. In addition, various types of touch screens can be implemented such as resistive, capacitive, infrared, and surface acoustic waves. Other input devices may include, but are not limited to, one or more of physical keyboards, function keys (such as volume control keys, power switch keys, etc.), trackballs, mice, joysticks, and the like. The controller 122 in the above-mentioned processor 12 can also control the input device 13 to receive the input signal or not to receive the input signal. In addition, inputted numerical or character information received by the input device 13 , and input of key signals generated related to user settings and function control of the electronic device may be stored in the internal memory 112 .

The output device 14 is used to output the signal corresponding to the data input by the input device 13 and stored in the internal memory 112 . For example, the output device 14 outputs a sound signal or a video signal. The controller 122 in the above-mentioned processor 12 may also control the output device 14 to output a signal or not to output a signal.

It should be noted that the thick arrows in FIG. 3 are used to indicate data transmission, and the direction of the thick arrows indicates the direction of data transmission. For example, a single arrow between input device 13 and internal memory 112 indicates that data received by input device 13 is transferred to internal memory 112 . For another example, the double arrow between the calculator 121 and the internal memory 112 indicates that the data stored in the internal memory 112 can be transferred to the calculator 121 , and the data processed by the calculator 121 can be transferred to the internal memory 112 . The thin arrows in FIG. 3 indicate components that the controller 122 can control. For example, the controller 122 can control the external memory device 111, the internal memory 112, the arithmetic unit 121, the input device 13, the output device 14, and the like.

Optionally, the electronic device 01 shown in FIG. 3 may further include various sensors. For example, a gyroscope sensor, a hygrometer sensor, an infrared sensor, a magnetometer sensor, etc., will not be repeated here. Optionally, the electronic device 01 may further include a wireless fidelity (wireless fidelity, WiFi) module, a Bluetooth module, etc., which will not be repeated here.

It can be understood that, in this embodiment of the present application, an electronic device (for example, the electronic device shown in FIG. 3 above) may perform some or all of the steps in the embodiment of the present application. These steps or operations are only examples, and the embodiment of the present application may also Perform other operations or variants of various operations. In addition, various steps may be performed in different orders presented in the embodiments of the present application, and may not be required to perform all the operations in the embodiments of the present application. Each embodiment of the present application may be implemented independently or in any combination, which is not limited in this application.

In order to further describe the structure of the electronic device 01 for convenience, the following takes the electronic device 01 as a mobile phone as an example for an exemplary introduction. As shown in FIG. 4 , the electronic device 01 may further include a middle frame 15 , a rear case 16 and a display screen 17 . The rear case 16 and the display screen 17 are respectively located on two sides of the middle frame 15 , and the middle frame 15 and the display screen 17 are arranged in the rear case 16 . The middle frame 15 includes a carrier board 150 for carrying the display screen 17 , and a frame 151 surrounding the carrier board 150 . The electronic device 01 may also include a circuit board disposed on the surface of the carrier board 150 facing the rear case 16. The circuit board may be, for example, a printed circuit board (printed circuit boards, PCB), and some electronic devices in the electronic device 01, such as the above-mentioned magnetic The random access memory 10 can be disposed on a circuit board; wherein, the magnetic random access memory 10 is electrically connected to the circuit board.

The embodiment of the present application further provides a magnetic random access memory, which can be applied to the above-mentioned electronic device 01 , for example, can be used as the internal memory 112 in the above-mentioned electronic device 01 .

As shown in FIG. 5 , the structure of the magnetic random access memory (hereinafter referred to as the memory 10 for short) provided by the embodiment of the present application includes a substrate (the substrate is not shown in FIG. 5 ) and a storage area disposed on the substrate and located in the memory 10 A plurality of memory cells 10A distributed in the inner array, the memory cell 10A includes a transistor T and a magnetic tunnel junction MTJ element 100 electrically connected to the transistor T. The memory 10 also includes a plurality of word lines (word lines, WL) and a plurality of bit lines (bit lines, BL) arranged in parallel arranged on the substrate, and the word lines WL and the bit lines BL cross each other, for example, The word line WL and the bit line BL are perpendicular to each other. In some examples, 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 of the transistor T is electrically connected to the word line WL, and the source or drain of the transistor T is electrically connected to the source line SL.

Since the MTJ element 100 is connected in series with the transistor T, the signal provided by the word line WL can control the transistor T to be in an on state or an off state, so as to control whether current flows through the MTJ element 100 to read and write data.

In some examples, 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 to the word line WL, so that the transistor T is turned on or off. When the transistor T is an N-type transistor, the high-level signal controls the transistor T to be turned on, and the low-level signal controls the transistor T to be turned off. When the transistor T is a P-type transistor, a low-level signal controls the transistor T to be turned on, and a high-level signal controls the transistor T to be turned off.

In some examples, the bit line BL is also electrically connected to a bit line control circuit through which the bit line BL is provided with signals.

In some examples, the source line SL is grounded.

As shown in FIG. 6, the above-mentioned MTJ element 100 includes a first electrode 101, a second electrode 102, and an MTJ disposed between the first electrode 101 and the second electrode 102; wherein, the first electrode 101 and the above-mentioned bit line BL Electrically connected, the second electrode 102 is electrically connected to the source or drain of the transistor T described above.

In the case where the source of the transistor T is electrically connected to the source line SL, the second electrode 102 is electrically connected to the drain of the transistor T. In the case where the drain of the transistor T is electrically connected to the source line SL, the second electrode 102 is electrically connected to the source of the transistor T. For convenience of description below, the second electrode 102 is electrically connected to the drain of the transistor T, and the source of the transistor T is electrically connected to the source line SL as an example.

In the prior art, an MTJ includes a pinned layer, a reference layer, a tunneling layer and a free layer that are stacked in sequence, wherein the material of the pinned layer is composed of a rare earth transition metal alloy. Since the rare earth transition metal alloy itself has strong perpendicular magnetic anisotropy, the pinned layer can have perpendicular magnetic anisotropy. In addition, by adjusting the ratio of rare earth elements and transition metal elements (transition metal elements are ferromagnetic materials) in the rare earth transition metal alloy, the coercive force (also called coercive magnetic field) Hc and magnetic moment Ms of the pinning layer can be adjusted , so that the pinning layer meets the requirements. FIG. 7 is a graph showing the relationship between the magnetic moment Ms and coercive force Hc of the pinning layer and the volume ratio of Tb in the CoTb alloy, taking Co as the transition metal element and Tb (terbium) as the rare earth element as an example. In FIG. 7 , the abscissa represents the volume ratio of Tb in the CoTb alloy, the left ordinate represents the magnetic moment Ms of the pinning layer, and the right ordinate represents the coercive force Hc of the pinning layer. It can be seen from Figure 7 that when the volume ratio of Tb is less than 0.325, with the increase of the ratio of Tb, the magnetic moment Ms gradually decreases, and the coercive force Hc gradually increases; when the volume ratio of Tb is greater than 0.35, with the increase of Tb With the increase of the volume ratio, the magnetic moment Ms gradually increases, and the coercive force Hc gradually decreases. Based on the relationship curves of the magnetic moment Ms and coercive force Hc of the pinning layer and the volume ratio of Tb in the CoTb alloy provided in FIG. 7 , the pinning can be adjusted by adjusting the ratio of rare earth elements and transition metal elements in the rare earth transition metal alloy. The magnetic moment Ms and the coercive force Hc of the pinned layer make the pinned layer have a fixed magnetization direction to achieve the effect of pinning.

However, when the material of the pinned layer is composed of rare earth transition metal alloys, the thermal stability of the pinned layer is poor, which leads to the easy loss of the perpendicular magnetic anisotropy of the pinned layer, which in turn leads to the failure of the MTJ. This is mainly because the reason why the pinned layer has perpendicular magnetic anisotropy when the material of the pinned layer is composed of a rare earth transition metal alloy is because atoms of rare earth elements and atoms of transition metal elements in the rare earth transition metal alloy have specific relative position. Taking the transition metal element as Co and the rare earth element as Tb as an example, when the material of the pinning layer is CoTb alloy, as shown in Figure 8, since Co atoms and Tb atoms have specific relative positions, CoTb alloys have different perpendicular magnetic properties. anisotropy. At high temperature, due to the diffusion of Co atoms and/or Tb atoms, the relative positions of Co atoms and Tb atoms will shift, resulting in the loss of perpendicular magnetic anisotropy or the weakening of perpendicular magnetic anisotropy in the pinned layer. , MTJ fails.

In addition, cobalt-iron-boron (CoFeB) alloy is often used as the material of the free layer and the reference layer in the MTJ, and the CoFeB alloy itself has no magnetism, and its magnetism mainly comes from the interface between CoFe and the tunneling layer (such as MgO). When the material of the layer and the reference layer is CoFeB alloy, the CoFeB alloy needs to be annealed and crystallized, so that B is precipitated, and CoFe is recrystallized to generate magnetism. However, when the material of the pinning layer is composed of a rare earth transition metal alloy, the thermal stability of the pinning layer is poor, and after annealing, the rare earth transition metal alloy will crystallize, that is, atoms of rare earth elements and atoms of transition metal elements will diffuse, As a result, the coercivity of the pinned layer decreases, and even the perpendicular magnetic anisotropy is lost.

In addition, STT MRAM uses current to read and write, and its operating temperature is higher. The experimental data show that when the material of the pinning layer is a rare earth transition metal alloy, even if the pinning layer retains part of the perpendicular magnetic anisotropy after annealing, when the operating temperature of the memory (for example, 125°C) is high, it tends to lose the magnetic anisotropy. Perpendicular Magnetic Anisotropy.

In addition, in the back of line (BEOL) process, when the MTJ distributed in the array is integrated on the substrate with the circuit structure made by the COMS process, the MTJ is specifically integrated between the two adjacent metal connection layers. in the vias of the insulating layer between them. In the BEOL process, high temperature annealing at about 400°C is required for several times. When integrating the MTJ array, if the material of the pinning layer in the MTJ is a rare earth transition metal alloy, for the MTJ integrated between the two adjacent metal connection layers in the lower layer, MTJs have a high risk of failure due to being subjected to multiple high temperature anneals.

In order to solve the problem that when the material of the pinning layer is composed of a rare earth transition metal alloy, the thermal stability of the rare earth transition metal alloy is poor, and the resulting pinning layer is easy to lose the perpendicular magnetic anisotropy after high temperature annealing or under high temperature working conditions, resulting in the MTJ in the For the problem of easy failure at high temperature, the embodiment of the present application provides an MTJ, which can be applied to the above-mentioned MTJ element 100 .

Four specific embodiments are provided below to exemplarily introduce the structure of the MTJ in the above-mentioned MTJ element 100 .

Example 1

As shown in FIGS. 9 a and 9 b , the MTJ includes a first pinning layer 1031 , a first reference layer 1032 , a first tunneling layer 1033 and a free layer 1034 which are stacked in sequence. The first pinned layer 1031 is the first pinned layer 1030, and the material of the first pinned layer 1030, that is, the first pinned layer 1031 includes a first rare earth transition metal alloy and a first rare earth transition metal alloy doped in the first rare earth transition metal alloy. doping elements.

It should be understood that the first reference layer 1032 is a film layer with a fixed magnetization direction in the MTJ, and there is a strong exchange coupling between the first pinning layer 1031 and the first reference layer (also referred to as a pinned layer) 1032 (exchange coupling), the magnetic moment direction (also called the magnetization direction) of the first reference layer 1032 can be pinned in a fixed direction by the first pinning layer 1031, and the magnetic moment direction of the first reference layer 1032 is difficult to being changed, the magnetization direction of the first reference layer 1032 and the magnetization direction of the first pinning layer 1031 are the same. In addition, since the first pinned layer 1031 is used to pin the magnetization direction of the first reference layer 1032 in a fixed direction, the magnetization direction of the first pinned layer 1031 should not be easily changed, that is, the first pinned layer 1031 should Has a large coercive field. The first reference layer 1032 and the free layer 1034 are in a decoupled state due to the action of the first tunneling layer 1033, so the magnetization direction of the free layer 1034 is easily changed under the action of an external magnetic field. The magnetization direction and the magnetization direction of the first reference layer 1032 may be in a parallel (ie, the same) or antiparallel (ie, opposite) state.

Based on the structure of the memory 10 described above, the working process of the memory 10 is described below by taking a storage unit 11 as an example.

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 1034 to the first reference layer 1032, that is, the spin electrons flow from the first reference layer 1032 to the free layer 1034, and the spin electrons pass through the first reference layer 1032. When the reference layer 1032 is used, the electrons in the current are spin polarized along the magnetization direction of the first reference layer 1032, the spin magnetic moment of the electrons is parallel to the magnetization direction of the first reference layer 1032, and the electrons pass through the first tunneling layer When 1033 reaches the free layer 1034, the spin electrons transfer the spin torque (also known as spin angular momentum, or STT) to the free layer 1034, and the free layer 1034 subjected to the effect of the spin torque has a small magnetization, so it is free. The magnetization direction of the layer 1034 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 1034 and the magnetization direction of the first reference layer 1032 are in a parallel state (that is, the magnetization of the free layer 1034). The direction is the same as the magnetization direction of the first reference layer 1032 ), at this time, it can represent writing the first logic information, and the first logic information can be marked as “0”, for example.

When the direction of the current flows from the first reference layer 1032 to the free layer 1034, that is, the spin electrons flow from the free layer 1034 to the first reference layer 1032, the spin electrons and the magnetic moments in the first reference layer 1032 are exchange-coupling, so that the spin electrons are exchanged with the magnetic moments in the first reference layer 1032. Electrons whose spins are parallel to the magnetization direction of the first reference layer 1032 pass through, while electrons whose spins are antiparallel to the magnetization direction of the first reference layer 1032 are reflected, and the reflected electrons pass through the first tunneling layer 1033 to reach the free layer 1034, and exchange coupling with the magnetic moment of the free layer 1034, so that the magnetization direction of the free layer 1034 rotates in the opposite direction of the magnetization direction of the first reference layer 1032, and finally the magnetization direction of the free layer 1034 and the magnetization direction of the first reference layer 1032 are in the same direction. The anti-parallel state (ie, the magnetization direction of the free layer 1034 is opposite to the magnetization direction of the first reference layer 1032 ) can represent writing second logic information, which can be marked as “1”, for example. Here, the current direction can be controlled by the voltage provided on the bit line BL and the source line SL. Referring to FIG. 6 , 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 1034 to the first reference layer. 1032 ; 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 1032 to the free layer 1034 .

When the memory cell 11 is being read, a constant small current flows from the bit line BL through the MTJ to the drain of the transistor T that is turned on, and a potential difference is generated across the MTJ. According to the magnitude of the potential difference, the resistance of the MTJ can be determined, that is, the relative orientation relationship between the magnetization directions of the free layer 1034 and the first reference layer 1032 can be obtained, and then it can be determined that the information stored in the storage unit 11 is the first logical information “0” Also the second logic information "1". Specifically, the MTJ exhibits low resistance, the magnetization direction of the free layer 1034 is parallel to the magnetization direction of the first reference layer 1032 , and the information stored in the memory unit 11 is the first logic information “0”; the MTJ exhibits high resistance, and the free layer 1034 The magnetization direction of the first reference layer 1032 is in an antiparallel state, and the information stored in the storage unit 11 is the second logic information "1".

It should be understood that when the memory 10 stores information and reads information, 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.

Based on the working principle of the above-mentioned storage unit 11 , the memory 10 provided in this embodiment of the present application may also be referred to as a spin-shift magnetic random access memory.

Here, the first tunneling layer 1033 is a non-magnetic layer, and the material of the first tunneling layer 1033 may include, for example, one or more of magnesium oxide (MgO) and aluminum oxide (Al ₂ O ₃ ).

In addition, the first reference layer 1032 and the free layer 1034 are magnetic layers, and the materials of the first reference layer 1032 and the free layer 1034 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.

In some examples, the transition metal element in the first rare earth transition metal alloy described above includes one or more of cobalt (Co), iron (Fe), and nickel (Ni).

In some examples, the rare earth element in the first rare earth transition metal alloy includes one or more of terbium (Tb), gadolinium (Gd), dysprosium (Dy), and cerium (Ce).

In some examples, the above-mentioned first doping element includes one or more of boron (B), carbon (C), and silicon (Si).

In this embodiment, since the material of the first pinning layer 1031 includes the first rare earth transition metal alloy and the first doping element, and the first rare earth transition metal alloy itself has strong perpendicular magnetic anisotropy, it can make The first pinned layer 1031 has perpendicular magnetic anisotropy, that is, the first pinned layer 1031 has a fixed magnetization direction.

It can be understood that the reason why the first pinned layer 1031 has perpendicular magnetic anisotropy is that atoms of rare earth elements and atoms of transition metal elements in the first rare earth transition metal alloy in the material of the first pinned layer 1031 have specific properties. relative position.

In addition, the coercive force of the first pinning layer 1031 (which may also be referred to as a coercive magnetic field) can be adjusted by adjusting the ratio of rare earth elements and transition metal elements in the first rare earth transition metal alloy in the material of the first pinning layer 1031 . ) Hc and magnetic moment Ms. In addition, the coercive force Hc and magnetic moment Ms of the first pinning layer 1031 can also be adjusted by adjusting the thickness of the first pinning layer 1031, so that the first pinning layer 1031 can be adapted to other layers in the corresponding MTJ .

It should be understood that, in order to prevent the magnetization direction of the first pinning layer 1031 from changing with the applied magnetic field, the coercive force Hc of the first pinning layer 1031 should be adjusted to be larger, and in order to avoid the The stray field affects the normal inversion of the free layer 1034 , so the magnetic moment Ms of the first pinned layer 1031 should be adjusted to be small, and the magnetic moment Ms may be about 0, for example.

FIG. 10 takes the rare earth element in the first rare earth transition metal alloy as Tb, the transition metal element as Co, and the first doping element as B as an example to illustrate the magnetic moment Ms and the coercive force Hc of the first pinning layer 1031, respectively. Graph of the relationship with the volume ratio of Tb. In FIG. 10 , the abscissa represents the volume ratio of Tb in the material of the first pinned layer 1031 , the ordinate on the left represents the magnetic moment Ms of the first pinned layer 1031 , and the ordinate on the right represents the magnetic moment of the first pinned layer 1031 . Coercivity Hc. It can be seen from Figure 10 that when the volume ratio of Tb is less than 20%, with the increase of the proportion of Tb, the magnetic moment Ms gradually decreases, and the coercive force Hc gradually increases; when the volume ratio of Tb is greater than 20%, the With the increase of the proportion of Tb, the magnetic moment Ms gradually increases, and the coercive force Hc gradually decreases. Based on the relationship curves of the magnetic moment Ms and the coercive force Hc of the first pinning layer 1031 and the volume ratio of Tb provided in FIG. 10 , the ratio of rare earth elements and transition metal elements in the first rare earth transition metal alloy can be adjusted by adjusting , to adjust the magnetic moment Ms and the coercive force Hc of the first pinned layer 1031 , so that the first pinned layer 1031 has a fixed magnetization direction to achieve the effect of pinning.

In addition, when forming the first pinning layer 1031, a suitable ratio of rare earth element and transition metal element can be selected by adjusting the energy of magnetization sputtering of rare earth element and transition metal element in the first rare earth transition metal alloy.

On this basis, in addition to the first rare earth transition metal alloy, the material of the first pinning layer 1031 also includes a first doping element, and the first doping element can form a barrier, which can block the first rare earth transition metal alloy The diffusion of atoms of rare earth elements and atoms of transition metal elements in the MTJ, so the relative positions of atoms of rare earth elements and atoms of transition metal elements in the first rare earth transition metal alloy will not be skewed after high temperature annealing or under high temperature working conditions. Therefore, the thermal stability of the first rare earth transition metal alloy can be improved, that is, the thermal stability of the first pinned layer 1031 can be improved. In this way, the first rare earth transition metal alloy still maintains the perpendicular magnetic anisotropy after high temperature annealing or under high temperature working conditions, that is, the first pinning layer 1031 still has perpendicular magnetic anisotropy after high temperature annealing or under high temperature working conditions Anisotropy.

Taking the transition metal element in the first rare earth transition metal alloy as Co, the rare earth element as Tb, and the first doping element as B in the material of the first pinning layer 1031 as an example, referring to FIG. 11 , since B atoms can block Co atoms and the diffusion of Tb atoms, so the relative positions of Co atoms and Tb atoms will not shift, or the shift is very small after MTJ annealing at high temperature or under high temperature working conditions, thus improving the first pinning layer 1031 Therefore, the CoTb alloy will still have perpendicular magnetic anisotropy after high temperature annealing or under high temperature working conditions.

In the related art, the pinning layer in the MTJ often adopts a SAF (synthetic anti-ferromagnetic, synthetic anti-ferromagnetic (also called artificial anti-ferromagnetic)) structure, and the artificial anti-ferromagnetic structure includes a first composite layer arranged in sequence. , a non-magnetic layer and a second composite layer, the first composite layer and the second composite layer are both composed of stacked alternating ferromagnetic layers and metal layers. In Figure 12, [Co/Pt] _M is the first composite layer, and [Co/Pt] _M indicates that the first composite layer includes an M layer of Co (cobalt) layer (ie, a ferromagnetic layer) and an M layer of Pt (platinum) layer (ie, a ferromagnetic layer). Metal layer), and Co layers and Pt layers are alternately stacked; [Co/Pt] _N is the second composite layer, [Co/Pt] _N indicates that the second composite layer includes N layers of Co layers and N layers of Pt layers, and Co Layers and Pt layers are alternately stacked; Ru is a non-magnetic layer.

Referring to FIG. 12 , since the pinning layer in the MTJ adopts the SAF structure in the related art, and the pinning layer is composed of multi-layer film layers, the thickness of the pinning layer is relatively large, resulting in a relatively large thickness of the MTJ. In this way, The integration difficulty of the MTJ array is increased, and the density of the MRAM is affected. The large thickness of the MTJ makes the integration of the MTJ array difficult and affects the increase in the density of the MRAM because: in the BEOL process, when the MTJ distributed in the array is integrated into the substrate with a circuit structure made by the COMS process, the specific The MTJ is integrated in the via (via) of the insulating layer between the two adjacent metal connection layers. If the thickness of the MTJ is large, the MTJ cannot be integrated in the via, which increases the integration difficulty of the MTJ array. . In addition, in the BEOL process, the distance between two adjacent metal connection layers gradually increases along the direction away from the substrate, that is, along the direction away from the substrate, the thickness of the insulating layer gradually increases, while the thickness of the via in the insulating layer gradually increases The thickness of the via is the same as the thickness of the insulating layer, that is, the thickness of the via gradually increases in the direction away from the substrate. If the thickness of the MTJ is small, the MTJ can be integrated in the vias in the multi-layer insulating layer. If the thickness of the MTJ is large, the MTJ can only be integrated in the vias of the upper insulating layer, which leads to the MTJ in the MRAM. Density decreases. Based on the above analysis, it can be seen that the thickness of the pinning layer in the MTJ affects the thickness of the MTJ, and the thickness of the MTJ affects the integration difficulty of the MTJ array and the density of the MRAM.

Compared with the SAF structure used for the pinning layer in the related art, that is, the pinning layer includes a multi-layer film layer, since the first pinning layer 1031 in this embodiment can be a single-layer structure, the first pinning layer provided in this embodiment The thickness of the pinned layer 1031 is greatly reduced, thereby reducing the thickness of the MTJ, thus reducing the integration difficulty of the MTJ array and increasing the density of the MRAM.

In addition, when the pinning layer adopts the SAF structure, the material of the pinning layer is generally 111 crystal orientation, and the material of the reference layer is generally 001 crystal orientation. It is difficult to grow the reference layer on the layer, which will cause the accumulation of roughness, the accumulation of stress, etc., resulting in the failure of the pinned layer. In this embodiment, since the material of the first pinning layer 1031 includes the first rare earth transition metal alloy and the first doping element doped in the first rare earth transition metal alloy, the material of the first pinning layer 1031 is Ferrimagnetic amorphous material. Amorphous materials are self-contained rather than interface type, and there is no requirement for the growth interface, so there will be no problems of roughness accumulation and stress accumulation. In this way, the first nail caused by roughness accumulation and stress accumulation can be solved. The problem of failure of the pinned layer 1031, and other layers, such as the first reference layer 1032, etc., can be directly grown on the first pinned layer 1031.

In this embodiment, since the material of the first pinning layer 1031 includes the first rare earth transition metal alloy and the first doping atom doped in the first rare earth transition metal alloy, and the rare earth element in the first rare earth transition metal alloy The atoms of α and the atoms of transition metal elements have specific relative positions, so that the first pinned layer 1031 can have perpendicular magnetic anisotropy. In order to avoid that the first doping element doped in the first rare earth transition metal alloy affects a specific relative position between the atoms of the rare earth element and the atoms of the transition metal element, in some examples, the first rare earth transition metal alloy is The atomic radius of the rare earth element and the atomic radius of the transition metal element are both larger than the atomic radius of the first doping element.

On this basis, the first rare earth transition metal alloy is doped with a first doping element, and the function of the first doping element is to block the rare earth in the first rare earth transition metal alloy after high temperature annealing or under high temperature working conditions The diffusion of the atoms of the element and the atoms of the transition metal element, that is, the relative position of the atoms of the rare earth element and the atoms of the transition metal element in the first rare earth transition metal alloy is blocked is shifted. Considering that if the atomic radius of the first doping element is too large, the doping of the first doping element in the first rare earth transition metal alloy may change the relationship between the atoms of the rare earth element and the transition metal element in the first rare earth transition metal alloy. relative positions between atoms, thereby causing the perpendicular magnetic anisotropy of the first pinned layer 1031 to weaken or disappear. If the atomic radius of the first doping element is too small, the first doping element is doped in the first rare earth transition metal alloy, which may not be able to block the atoms of the rare earth element and the transition metal element in the first rare earth transition metal alloy. The role of atomic diffusion. Based on this, in some examples, the atomic radius of the first doping element ranges from 53 pm (picometer) to 125 pm.

For example, the atomic radius of the first doping element may be, for example, 53 pm, 77 pm, 82 pm, 118 pm, or 125 pm.

In addition, considering that if the amount of the first doping element doped in the material of the first pinning layer 1031 is too large, the amount of the first rare earth transition metal alloy will be reduced, which may affect the first doping element. The perpendicular magnetic anisotropy of the pinned layer 1031 . Based on this, in some examples, the ratio of the volume of the first doping element to the sum of the volume of the first rare earth transition metal alloy and the first doping element ranges from (0, 50%), that is, the volume of the first doping element is in the range of (0, 50%). The ratio of the volume to the sum of the volume of the first rare earth transition metal alloy and the first doping element is greater than 0 and less than or equal to 50%.

Exemplarily, the ratio of the volume of the first doping element to the total volume of the first rare earth transition metal alloy and the first doping element may be 10%, 20%, 40%, or 50%, or the like.

When the pinned layer adopts the SAF structure, since the pinned layer includes multiple layers, when the MTJ is fabricated, if the free layer is formed first, and then the pinned layer is formed, it will cause the accumulation of roughness and stress in the upper layer and reduce the MTJ. Therefore, when the pinned layer adopts the SAF structure, when making the MTJ, the pinned layer is usually made first, and then the free layer is made. In this embodiment, since the first pinned layer 1031 is an amorphous material, even if the free layer 1034 is formed first and then the first pinned layer 1031 is formed, the upper layer roughness and stress caused by the first pinned layer 1031 are accumulated The accumulation is also relatively small and will not affect the performance of the MTJ. Based on this, this embodiment does not limit the order in which the layers in the MTJ are formed.

In some examples, as shown in FIG. 9a, the first pinned layer 1031 in the MTJ is close to the second electrode 102 relative to the free layer 1034, ie, each of the MTJs is formed in the order of the first pinned layer 1031 to the free layer 1034. Floor.

In other examples, as shown in FIG. 9b, the free layer 1034 in the MTJ is close to the second electrode 102 relative to the first pinned layer 1031, that is, the free layer 1034 to the first pinned layer 1031 is formed in the order of the MTJ. layers.

Since the material of the first pinned layer 1031 is an amorphous material, roughness accumulation and stress accumulation will not occur. Therefore, when the MTJ is fabricated, the free layer 1034 can be formed first, and then the first pinned layer 1031 can be formed. In this case, in some examples, as shown in FIG. 9b, the free layer 1034 is in contact with the second electrode 102; the second electrode 102 is multiplexed as a spin orbit torque (SOT) providing layer.

When the second electrode 102 is multiplexed as a spin-orbit torque providing layer, the material of the second electrode 122 can be, for example, one or more of heavy metal element, heavy metal alloy, topological insulator or Weyl semimetal.

Exemplarily, the heavy metal element may be one or more of platinum (Pt), tantalum (Ta), copper (Cu), iridium (Ir), ruthenium (Ru) or tungsten (W).

Exemplarily, the heavy metal alloy may be an alloy composed of two or more of platinum, tantalum, copper, iridium, ruthenium or tungsten.

Illustratively, 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.

Illustratively, the Weyl semimetal may be tungsten ditelluride (WTe ₂ ).

In addition, 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 1034 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 1034 ), and the generated spin-orbit torque SOT induces the free layer 1034 The magnetization is reversed. By passing a 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 (such as the first logic information "1") can be realized. ) or writing in a low resistance state (eg, second logic information "0").

It should be noted that, when the second electrode 102 is multiplexed as a spin-orbit torque supply layer, when the MTJ writes storage information, the transistor T is turned on, and the bit line BL writes current. On the one hand, the first reference layer 1032 provides The spin shift distance STT flips the free layer 1034 , on the other hand, the spin-orbit moment providing layer provides the spin-orbit moment SOT flips the free layer 1034 . Since the free layer 1034 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 1034 can be greatly reduced.

When the second electrode 102 is multiplexed as a spin-orbit torque providing layer, the reading process of the MTJ is the same as the above-mentioned reading process, which is not repeated here.

Based on the above, in some examples, as shown in FIG. 13 , the MTJ further includes a capping layer 1035 that is in contact with the first electrode 101 .

It should be noted that when the MTJ further includes the cover layer 1035 , the free layer 1034 may be close to the cover layer 1035 relative to the first pinned layer 1031 , or the first pinned layer 1031 may be close to the cover layer 1035 relative to the free layer 1034 . FIG. 13 illustrates by taking an example that the first pinned layer 1031 is close to the cover layer 1035 relative to the free layer 1034 .

Here, the material of the capping layer 1035 may include magnesium oxide, for example.

In the case where the MTJ includes the capping layer 1035, the interface between the capping layer 1035 and the magnetic layer in contact with it, such as the first pinning layer 1031, is beneficial to increase the perpendicular magnetic anisotropy of the first pinning layer 1031, so that the increase can be achieved Purpose of data retention time.

Embodiment 2

As shown in FIG. 14 , the MTJ includes a first pinning layer 1031 , a first reference layer 1032 , a first tunneling layer 1033 and a free layer 1034 that are stacked in sequence. The first reference layer 1032 is the first pinned layer 1030, and the material of the first pinned layer 1030 (ie, the first reference layer 1032) includes a first rare earth transition metal alloy and a first rare earth transition metal alloy doped in the first rare earth transition metal alloy. doping elements.

It should be noted that, in this embodiment, the working process of the memory is the same as that of the first embodiment, and reference may be made to the first embodiment, which will not be repeated here.

Here, the material of the first tunneling layer 1033, the material of the free layer 1034, the material and ratio of the first rare earth transition metal alloy and the first doping element in the first pinned layer 1030, the atomic radius of the first doping element, etc. All can refer to Embodiment 1, and details are not repeated here.

In addition, the order in which each layer in the MTJ is formed may refer to Embodiment 1, which will not be repeated here.

In this embodiment, since the first reference layer 1032 is the first pinned layer 1030, the material of the first pinned layer 1030 includes the first rare earth transition metal alloy and the first doping element doped in the first rare earth transition metal alloy , and the first rare earth transition metal alloy itself has strong perpendicular magnetic anisotropy, so the first reference layer 1032 has strong perpendicular magnetic anisotropy. Based on this, in some examples, the first pinning layer 1031 may not be provided in the MTJ.

In the case where the MTJ includes a first pinned layer 1031, in some examples, as shown in FIG. 15, the first pinned layer 1031 may adopt a SAF structure, that is, the first pinned layer 1031 includes a stack of layers along the MTJ The first composite layer 1031a, the non-magnetic layer 1031b and the second composite layer 1031c are stacked in sequence in the direction; wherein, as shown in FIG. and the metal layer (ie, the non-magnetic layer); the magnetization direction of the first composite layer 1031a is opposite to the magnetization direction of the second composite layer 1031c.

In the case where the first pinning layer 1031 adopts the SAF structure, in order to avoid the roughness accumulation and stress accumulation caused by the first pinning layer 1031 disposed on the upper layer of the MTJ, which affects the performance of the MTJ, in some examples, as shown in FIG. 15 As shown, the first pinned layer 1031 is close to the second electrode 102 relative to the free layer 1034 .

It should be noted that the magnetization direction of the first composite layer 1031a in the first pinned layer 1031 is opposite to the magnetization direction of the second composite layer 1031c, and the magnetization direction of the first pinned layer 1031 is the same as that of the first composite layer 1031a and the second composite layer 1031a. The magnetization direction of the one of the layers 1031c that is close to the free layer 1034 is the same. 15, since the second composite layer 1031c is close to the free layer 1034, the magnetization direction of the first pinned layer 1031 is the same as that of the second composite layer 1031c. And the magnetization direction of the first reference layer 1032 is the same as the magnetization direction of the first pinning layer 1031, so the magnetization direction of the first reference layer 1032 is the same as the magnetization direction of the adjacent one of the first composite layer 1031a and the second composite layer 1031c. .

In some examples, the materials of the non-magnetic layer 1031b include platinum element, tantalum element, copper (Cu) element, iridium (Ir) element, ruthenium (Ru) element, tungsten (W) element, and elements including platinum, tantalum, copper, One or more of an alloy of at least one of iridium, ruthenium, and tungsten.

In some examples, the material of the ferromagnetic layer includes one or more of cobalt element, iron element, nickel element, and an alloy containing at least one of cobalt, iron, and nickel.

In some examples, the material of the metal layer includes platinum element, tantalum element, copper element, iridium element, ruthenium element, tungsten element, and one of alloys including at least one of platinum, tantalum, copper, iridium, ruthenium, and tungsten. one or more.

In addition, the number of ferromagnetic layers and the number of metal layers in the first composite layer 1031a may be the same or different. The number of ferromagnetic layers and the number of metal layers in the second composite layer 1031c may be the same or different. In addition, the number of ferromagnetic layers in the first composite layer 1031a and the number of ferromagnetic layers in the second composite layer 1031c may be the same or different. The number of metal layers in the first composite layer 1031a and the number of metal layers in the second composite layer 1031c may be the same or different.

For example, the first composite layer 1031a includes cobalt layers and platinum layers alternately stacked along the stacking direction of the layers in the MTJ ([Co/Pt]m, where m is a positive integer, indicating the number of layers of cobalt layers and the number of layers of platinum layers. ).

On this basis, in some examples, the MTJ may further include a cover layer, and the material, setting position and function of the cover layer may refer to Embodiment 1, which will not be repeated here.

In this embodiment, since the material of the first reference layer 1032 includes the first rare earth transition metal alloy, and the first rare earth transition metal alloy itself has strong perpendicular magnetic anisotropy, the first reference layer 1032 has perpendicular magnetic anisotropy anisotropy. In addition, the material of the first reference layer 1032 includes the first doping element in addition to the first rare earth transition metal alloy, and the first doping element can form a barrier, which can block the rare earth element in the first rare earth transition metal alloy. The diffusion of atoms and atoms of transition metal elements, so the relative positions of atoms of rare earth elements and atoms of transition metal elements in the first rare earth transition metal alloy will not shift, or the relative positions of MTJ after high temperature annealing or under high temperature working conditions. Therefore, the thermal stability of the first rare earth transition metal alloy can be improved, that is, the thermal stability of the first reference layer 1032 can be improved. In this way, the first rare earth transition metal alloy still maintains the perpendicular magnetic anisotropy after high temperature annealing or under high temperature working conditions, that is, the first reference layer 1032 still has perpendicular magnetic anisotropy after high temperature annealing or under high temperature working conditions. anisotropy.

Embodiment 3

As shown in FIG. 17a and FIG. 17b , the MTJ includes a first pinning layer 1031, a first reference layer 1032, a first tunneling layer 1033 and a free layer 1034 that are stacked in sequence, and the MTJ also includes a stack of layers away from the free layer 1034. The second tunneling layer 1036 , the second reference layer 1037 and the second pinning layer 1038 on one side of the first tunneling layer 1033 .

The magnetization direction of the first pinning layer 1031 is opposite to the magnetization direction of the second pinning layer 1038 , and the resistance of the first tunneling layer 1033 is different from that of the second tunneling layer 1036 . The first pinned layer 1031 or the first reference layer 1032 is the first pinned layer 1030, and the material of the first pinned layer 1030 includes a first rare earth transition metal alloy and a first doping element doped in the first rare earth transition metal alloy .

In this embodiment, the first pinned layer 1031 may be the first pinned layer 1030 . In this case, with respect to the first pinned layer 1031 , the first reference layer 1032 , the first tunneling layer 1033 and the free layer 1034 For the description, refer to Embodiment 1. The first reference layer 1032 may also be the first pinned layer 1030. In this case, the description of the first pinned layer 1031, the first reference layer 1032, the first tunneling layer 1033 and the free layer 1034 may refer to the embodiments two. 17a and 17b both take the first pinning layer 1031 as the first pinning layer 1030 as an example for illustration.

Here, the first pinned layer 1031 is used to pin the magnetization direction of the first reference layer 1032 in a fixed direction, the magnetization direction of the first reference layer 1032 is the same as the magnetization direction of the first pinned layer 1031, The pinned layer 1038 is used to pin the magnetization direction of the second reference layer 1037 in a fixed direction, and the magnetization direction of the second reference layer 1037 is the same as the magnetization direction of the second pinned layer 1038 . Since the magnetization direction of the first pinned layer 1031 is opposite to that of the second pinned layer 1038 , the magnetization direction of the first reference layer 1032 is opposite to that of the second reference layer 1037 .

In this embodiment, the writing process of the MTJ is as follows: when the current flows from the second pinning layer 1038 to the first pinning layer 1031 , that is, the spin electrons flow from the first pinning layer 1031 to the second pinning layer 1038 , the When the spin electrons pass through the first reference layer 1032, the electrons in the current are spin polarized along the magnetization direction of the first reference layer 1032, and the spin magnetic moment of the electrons is parallel to the magnetization direction of the first reference layer 1032, and the electrons pass through When the first tunneling layer 1033 reaches the free layer 1034, the spin electrons transfer the spin torque, that is, the spin angular momentum to the free layer 1034, and the magnetization direction of the free layer 1034 can be determined according to the polarization direction of the spin electrons in the spin current. It changes freely, and the magnetization direction of the free layer 1034 is parallel to the magnetization direction of the first reference layer 1032. When the spin electrons pass through the second tunneling layer 1036 to reach the second reference layer 1037, because the magnetization direction of the second reference layer 1037 is the same as that of the second reference layer 1037. The magnetization direction of the first reference layer 1032 is opposite, and the spin magnetic moment of the electrons is parallel to the magnetization direction of the first reference layer 1032, so the spin electrons cannot pass through the second reference layer 1037. According to the law of conservation of momentum, the second reference layer 1037 The angular momentum is transferred to the spin electrons, and the spin electrons are reflected to the free layer 1034 by the second reference layer 1037 , further making the magnetization direction of the free layer 1034 and the magnetization direction of the first reference layer 1032 parallel.

When the current flows from the first pinned layer 1031 to the second pinned layer 1038 , that is, the spin electrons flow from the second pinned layer 1038 to the first pinned layer 1031 , the process is similar to the above process and will not be repeated here. Finally, the free layer The magnetization direction of 1034 is parallel to the magnetization direction of the second reference layer 1037 .

Since the resistances of the first tunneling layer 1033 and the second tunneling layer 1036 are different, taking the resistance of the first tunneling layer 1033 greater than the resistance of the second tunneling layer 1036 as an example, the current flows from the second pinning layer 1038 to the first tunneling layer 1038 . When the pinned layer 1031, or the current flows from the first pinned layer 1031 to the second pinned layer 1038, when the magnetization direction of the free layer 1034 is the same as the magnetization direction of the first pinned layer 1031 close to the first tunneling layer 1033, At this time, the memory cell is in a low-resistance state, and the first logic information is written, for example, the first logic information can be recorded as "0"; The magnetization direction is opposite, and the memory cell is in a high resistance state at this time, and the second logic information is written, for example, the second logic information can be recorded as "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.

According to the above MTJ writing process, both the first reference layer 1032 and the second reference layer 1037 can provide spin transfer torque, so the current required for the flipping of the free layer 1034 can be greatly reduced. In theory, the current required for flipping the free layer 1034 It can be reduced by 50%, which can reduce power consumption.

Here, as shown in FIG. 17a, the second pinned layer 1038 is close to the first electrode 101, and the first pinned layer 1031 is close to the second electrode 102; or as shown in FIG. 17b, the first pinned layer 1031 Close to the first electrode 101 , the second pinned layer 1038 is close to the second electrode 102 .

In addition, the second tunneling layer 1036 is a non-magnetic layer, and the material of the second tunneling layer 1036 may include, for example, one or more of MgO and Al ₂ O ₃ . The material of the first tunneling layer 1033 and the material of the second tunneling layer 1036 may be the same or different.

In addition, the material of the second reference layer 1037 may include, for example, one or more of CoFeB alloy, CoFe alloy or NiFeCo alloy. The material of the first reference layer 1032 and the material of the second reference layer 1037 may be the same or different.

In this embodiment, the second pinning layer 1038 may or may not be provided in the MTJ. In the case where the MTJ includes the second pinning layer 1038 , in this embodiment, the second pinning layer 1038 exemplarily may include the following two implementations.

The first:

As shown in FIG. 17a, the second pinning layer 1038 is a second pinned layer 1040, and the material of the second pinned layer 1040 includes a second rare earth transition metal alloy and a second doping element doped in the second rare earth transition metal alloy .

FIG. 17 a is a schematic diagram illustrating an example where the first pinned layer 1031 is the first fixed layer 1030 , and the first pinned layer 1031 is closer to the second electrode 102 than the second pinned layer 1038 .

In some examples, the transition metal element in the second rare earth transition metal alloy described above includes one or more of Co, Fe, and Ni. The transition metal element in the second rare earth transition metal alloy and the transition metal element in the first rare earth transition metal alloy may be the same or different.

In some examples, the rare earth elements in the second rare earth transition metal alloy described above include one or more of Tb, Gd, Dy, and Ce. Wherein, the rare earth element in the second rare earth transition metal alloy and the rare earth element in the first rare earth transition metal alloy may be the same or different.

In addition, the second rare earth transition metal alloy and the first rare earth transition metal alloy may be the same or different.

In some examples, the above-mentioned second doping element includes one or more of B, C, and Si. Wherein, the second doping element and the first doping element may be the same or different.

When the material of the second pinning layer 1038 includes the second rare earth transition metal alloy and the second doping element doped in the second rare earth transition metal alloy, the second pinning layer 1038 has the same characteristics as the first pin in the first embodiment. The technical effect of the pinned layer 1031 is the same, which is not repeated here.

In some examples, the atomic radius of the rare earth element and the atomic radius of the transition metal element in the second rare earth transition metal alloy are both greater than the atomic radius of the second dopant element.

In some examples, the atomic radius of the second doping element ranges from 53 pm to 125 pm.

Here, the atomic radius of the second doping element may be, for example, 53 pm, 77 pm, 82 pm, 118 pm, or 125 pm.

It should be noted that the atomic radius of the second doping element and the atomic radius of the first doping element may be the same or different.

In some examples, the ratio of the volume of the second doping element to the sum of the volume of the second rare earth transition metal alloy and the second doping element ranges from (0, 50%), that is, the volume of the second doping element accounts for The ratio of the volume sum of the second rare earth transition metal alloy and the second doping element is greater than 0 and less than or equal to 50%.

Here, the ratio of the volume of the second doping element to the total volume of the second rare earth transition metal alloy and the second doping element may be, for example, 10%, 20%, 40%, or 50%.

It should be noted that the ratio of the volume of the second doping element to the sum of the volume of the second rare earth transition metal alloy and the second doping element is the same as the volume of the first doping element accounting for the volume of the first rare earth transition metal alloy and the first doping element. The ratio of the volume sum of the doping elements may be the same or different.

Compared with the MTJ including double pinning layers in the prior art, that is, the MTJ includes a first pinning layer and a second pinning layer, since both the first pinning layer and the second pinning layer in the prior art adopt the SAF structure, Therefore, the thickness of the MTJ is larger. In the case where the second pinning layer 1038 adopts the first implementation manner, since the material of the second pinning layer 1038 includes the second rare earth transition metal alloy and the second doping element, the second pinning layer 1038 may be both Single-layer structure, so the thickness of the MTJ can be greatly reduced, thereby reducing the thickness of the MTJ, thus reducing the integration difficulty of the MTJ array and increasing the density of the MRAM.

The second:

As shown in FIG. 18 , the second pinned layer 1038 has a SAF structure, that is, the second pinned layer 1038 includes a first composite layer 1031 a , a non-magnetic layer 1031 b and a second composite layer 1031 a , a non-magnetic layer 1031 b and a second composite layer that are sequentially stacked along the stacking direction of the layers in the MTJ. layer 1031c; wherein, the first composite layer 1031a and the second composite layer 1031c both include alternately stacked ferromagnetic layers and metal layers; the magnetization direction of the first composite layer 1031a and the magnetization direction of the second composite layer 1031c are opposite.

Here, the structures of the first composite layer 1031a and the second composite layer 1031c may refer to FIG. 16 .

FIG. 18 takes the first pinned layer 1031 as the first pinned layer 1030 as an example for illustration.

When the second pinned layer 1038 adopts the second implementation manner, and the first pinned layer 1031 is the first pinned layer 1030 or the first pinned layer 1031 is not provided, in order to avoid the second pinned layer 1038 being provided in the The upper layer of the MTJ causes roughness accumulation and stress accumulation, which affects the performance of the MTJ, so in some examples, as shown in FIG. 18 , the second pinned layer 1038 is closer to the second electrode 102 than the first The electrode 102 is electrically connected to the drain of the transistor T.

It should be noted that the magnetization direction of the first composite layer 1031a in the second pinned layer 1038 is opposite to the magnetization direction of the second composite layer 1031c, and the magnetization direction of the second pinned layer 1038 is the same as that of the first composite layer 1031a and the second composite layer 1031a. The magnetization direction of the one of the layers 1031c that is close to the free layer 1034 is the same. 18, since the first composite layer 1031a is close to the free layer 1034, the magnetization direction of the second pinned layer 1038 is the same as that of the first composite layer 1031a. And the magnetization direction of the second reference layer 1037 is the same as the magnetization direction of the second pinning layer 1038, so the magnetization direction of the second reference layer 1037 is the same as the magnetization direction of the first composite layer 1031a and the second composite layer 1031c that are close to each other. .

Here, for the materials of the first composite layer 1031a, the non-magnetic layer 1031b and the second composite layer 1031c, reference may be made to the second embodiment, and details are not repeated here.

In the case where the second pinning layer 1038 adopts the second implementation manner, in some examples, as shown in FIG. For the lattice conversion layer 1039, the material of the lattice conversion layer 1039 is an amorphous material.

For example, the material of the lattice conversion layer 1039 is one or more of tantalum (Ta), tantalum alloy, and tantalum-tungsten alloy. Among them, tantalum is an amorphous material.

Since the MTJ further includes a lattice conversion layer 1039 disposed between the second pinning layer 1038 and the second reference layer 1037, and the material of the lattice conversion layer 1039 is an amorphous material, and the amorphous material has no fixed crystal orientation, Therefore, growing other layers such as the second reference layer 1037 on the lattice conversion layer 1039 can avoid growth difficulties caused by lattice differences, and problems such as roughness accumulation and stress accumulation.

Based on the above, in the third embodiment, in some examples, as shown in FIG. 20 , the MTJ further includes a cover layer 1035 , and the cover layer 1035 is in contact with the first electrode 101 .

Here, for the material and function of the cover layer 1035, reference may be made to the first embodiment, which will not be repeated here.

Embodiment 4

As shown in FIG. 21 , the MTJ includes a first pinning layer 1031 , a first reference layer 1032 , a first tunneling layer 1033 and a free layer 1034 that are stacked in sequence, and the MTJ also includes that the free layer 1034 is stacked away from the first tunnel in sequence. The second tunneling layer 1036 , the second reference layer 1037 and the second pinning layer 1038 on one side of the through layer 1033 .

The magnetization direction of the first pinning layer 1031 is opposite to the magnetization direction of the second pinning layer 1038 , and the resistance of the first tunneling layer 1033 is different from that of the second tunneling layer 1036 . The first pinned layer 1031 or the first reference layer 1032 is the first pinned layer 1030, and the material of the first pinned layer 1030 includes a first rare earth transition metal alloy and a first doping element doped in the first rare earth transition metal alloy . The second reference layer 1037 is the second pinned layer 1040, and the material of the second pinned layer 1040 includes a second rare earth transition metal alloy and a second doping element doped in the second rare earth transition metal alloy.

It should be noted that, in this embodiment, the working process of the memory is the same as that of the third embodiment, and reference may be made to the third embodiment, which will not be repeated here.

In this embodiment, the first pinned layer 1031 may be the first pinned layer 1030 . In this case, with respect to the first pinned layer 1031 , the first reference layer 1032 , the first tunneling layer 1033 and the free layer 1034 For the description, refer to Embodiment 1. The first reference layer 1032 may also be the first pinned layer 1030. In this case, the description of the first pinned layer 1031, the first reference layer 1032, the first tunneling layer 1033 and the free layer 1034 may refer to the embodiments two. FIG. 21 takes the first pinned layer 1031 as the first pinned layer 1030 as an example for illustration.

Here, the material of the second tunneling layer 1036, the second rare earth transition metal alloy in the second pinned layer 1040, the material and ratio of the second doping element, the atomic radius of the second doping element, etc. can all refer to the third embodiment , and will not be repeated here.

In this embodiment, since the second reference layer 1037 is the second pinned layer 1040 , the material of the second pinned layer 1040 includes the second rare earth transition metal alloy and the second doping element, and the second rare earth transition metal alloy has perpendicular magnetic properties anisotropy, so the second reference layer 1037 has strong perpendicular magnetic anisotropy. Based on this, in some examples, the second pinning layer 1038 may not be provided in the MTJ.

In the case where the MTJ includes the second pinning layer 1038, in some examples, the second pinning layer 1038 may be implemented in the second manner in the third embodiment above, and reference may be made to the third embodiment, which will not be repeated here.

In the case where the second pinning layer 1038 adopts the SAF structure, and the first pinning layer 1031 is the first pinning layer 1030 or the first pinning layer 1031 is not provided, in order to avoid the second pinning layer 1038 being provided on the upper layer of the MTJ Roughness accumulation and stress accumulation are caused, affecting the performance of the MTJ, so in some examples, as shown in FIG.

In this embodiment, the second reference layer 1037 is the second fixed layer 1040 , and the second reference layer 1037 has the same technical effect as the first reference layer 1032 in the second embodiment. Please refer to the second embodiment, which will not be repeated here. .

In another aspect of the present application, there is also provided 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.

The above are only specific embodiments of the present application, but the protection scope of the present application is not limited to this. should be covered within the scope of protection of this application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

A memory, characterized by comprising a plurality of memory cells distributed in an array, the memory cells comprising a transistor and a magnetic tunnel junction MTJ element electrically connected to the transistor;

The MTJ element includes a first electrode, a second electrode, and an MTJ disposed between the first electrode and the second electrode;

The MTJ includes a first fixed layer, a first tunneling layer and a free layer that are stacked in sequence;

Wherein, the material of the first pinned layer includes a first rare earth transition metal alloy and a first doping element doped in the first rare earth transition metal alloy.
The memory according to claim 1, wherein the atomic radius of the rare earth element and the atomic radius of the transition metal element in the first rare earth transition metal alloy are both larger than the atomic radius of the first doping element.
The memory according to claim 2, wherein the atomic radius of the first doping element ranges from 53pm to 125pm.
The memory according to any one of claims 1-3, wherein the first doping element comprises one or more of boron, carbon, and silicon.
The memory according to any one of claims 1-4, wherein the volume of the first doping element accounts for a ratio of the volume of the first rare earth transition metal alloy and the first doping element to the sum of the volumes The range is (0, 50%].
The memory device according to any one of claims 1-5, wherein the rare earth element in the first rare earth transition metal alloy comprises one or more of terbium, gadolinium, dysprosium, and cerium.
The memory device according to any one of claims 1-6, wherein the transition metal element in the first rare earth transition metal alloy comprises one or more of cobalt, iron, and nickel.
The memory according to any one of claims 1-7, wherein the first fixed layer is a first reference layer;

Alternatively, the first pinned layer is a first pinned layer, and the MTJ further includes a first reference layer disposed between the first pinned layer and the first tunneling layer.
The memory according to any one of claims 1-8, wherein the second electrode is electrically connected to a source or a drain of the transistor;

The free layer is close to the second electrode relative to the first pinned layer; alternatively, the first pinned layer is close to the second electrode relative to the free layer.
The memory according to any one of claims 1-8, wherein the second electrode is electrically connected to a source or a drain of the transistor;

The free layer is in contact with the second electrode; the second electrode is multiplexed as a spin-orbit torque providing layer.
The memory according to any one of claims 1-9, wherein the MTJ further comprises a second tunneling layer and a second tunneling layer that are sequentially stacked on a side of the free layer away from the first tunneling layer fixed layer;

Wherein, the magnetization direction of the first pinned layer is opposite to the magnetization direction of the second pinned layer, and the resistance of the first tunneling layer is different from that of the second tunneling layer.
The memory device of claim 11, wherein the material of the second pinned layer comprises a second rare earth transition metal alloy and a second doping element doped in the second rare earth transition metal alloy.
The memory device of claim 12, wherein the atomic radius of the rare earth element and the atomic radius of the transition metal element in the second rare earth transition metal alloy are both larger than the atomic radius of the second doping element.
The memory according to claim 13, wherein the atomic radius of the second doping element ranges from 53pm to 125pm.
The memory according to any one of claims 12-14, wherein the second doping element comprises one or more of boron, carbon, and silicon.
The memory according to any one of claims 12 to 15, wherein the volume of the second doping element accounts for a ratio of the volume of the second rare earth transition metal alloy and the second doping element to the sum of the volumes The range is (0, 50%].
The memory according to any one of claims 11-16, wherein the second pinned layer is a second pinned layer, and the MTJ further comprises a layer disposed on the second tunneling layer and the second pinned layer. A second reference layer between pinned layers.
The memory according to any one of claims 11-16, wherein the second fixed layer is a second reference layer.
The memory of claim 18, wherein the MTJ further comprises a second pinned layer disposed on a side of the second reference layer away from the free layer; the second pinned layer comprises a The first composite layer, the non-magnetic layer and the second composite layer are stacked in sequence in the stacking direction of each layer in the MTJ;

Wherein, the first composite layer and the second composite layer both include ferromagnetic layers and metal layers alternately stacked; the magnetization direction of the first composite layer is opposite to the magnetization direction of the second composite layer.
The memory according to claim 19, wherein the second electrode is electrically connected to the source or the drain of the transistor;

The second pinned layer is proximate to the second electrode relative to the free layer.
The memory according to claim 19 or 20, wherein the MTJ further comprises a lattice conversion layer disposed between the second pinning layer and the second tunneling layer, the lattice conversion layer The material of the layer is an amorphous material.
An electronic device comprising a circuit board and a memory electrically connected to the circuit board, wherein the memory is the memory according to any one of claims 1-21.