CN106025063B - Magnetic Tunnel Junction and Magnetic Memory - Google Patents

Abstract

The embodiment of the present invention discloses a magnetic tunnel junction MTJ and a magnetic memory, the MTJ sequentially includes a first ferromagnetic layer, a barrier layer, a second ferromagnetic layer, a buffer layer, a third ferromagnetic layer and a heavy metal layer from top to bottom , wherein: the first ferromagnetic layer, the second ferromagnetic layer and the third ferromagnetic layer all include mixed metal materials, the barrier layer includes metal oxide materials, and the buffer layer includes non-ferromagnetic materials; the magnetization of the first ferromagnetic layer The direction is a fixed direction, and the second ferromagnetic layer forms a ferromagnetic coupling or an antiferromagnetic coupling with the third ferromagnetic layer. By implementing the embodiments of the present invention, the switching speed of the magnetization direction of the third ferromagnetic layer in the magnetic tunnel junction can be increased, the reliability of the MTJ can be improved, and the writing current can be reduced, thereby reducing power consumption.

Description

Magnetic Tunnel Junction and Magnetic Memory

technical field

The invention relates to the technical field of communication, in particular to a magnetic tunnel junction and a magnetic memory.

Background technique

Magnetic memory is a memory that stores data information through magnetoresistive properties. Due to the advantages of stable non-volatility and unlimited read times, magnetic memory has been extensively studied at present. The core storage part of the magnetic memory is the magnetic tunnel junction (English: Magnetic Tunnel Junction, referred to as MTJ). As shown in Figure 1, the MTJ includes a first ferromagnetic layer and a second ferromagnetic layer, and the magnetization direction of the first ferromagnetic layer is fixed. unchanged, it is the reference layer, and the magnetization direction of the second ferromagnetic layer can be parallel or antiparallel to the reference layer, and it is the storage layer. When the magnetization directions of the storage layer and the reference layer are parallel, the MTJ presents a low-resistance state; when the magnetization directions of the storage layer and the reference layer are antiparallel, the MTJ presents a high-resistance state; when information is stored, when the MTJ presents a low-resistance state, It represents the binary data "0", and when the MTJ is in a high resistance state, it represents the binary data "1". The magnetic memory changes the magnetization direction of the storage layer through the spin-transfer torque (English: Spin-Transfer Torque, referred to as STT). When the current passes through the MTJ, the STT and the magnetization direction of the storage layer are collinear, and disturbance is required to realize the flip, resulting in the The magnetization direction is reversed at a slower rate.

Contents of the invention

The embodiment of the present invention discloses a magnetic tunnel junction and a magnetic memory, which can increase the inversion speed of the magnetization direction of the storage layer in the magnetic tunnel junction, improve the reliability of the MTJ, and reduce the write current, thereby reducing power consumption.

The first aspect of the embodiment of the present invention provides a magnetic tunnel junction MTJ, which sequentially includes a first ferromagnetic layer, a barrier layer, a second ferromagnetic layer, a buffer layer, a third ferromagnetic layer and a heavy metal layer from top to bottom ,in:

Each of the first ferromagnetic layer, the second ferromagnetic layer, and the third ferromagnetic layer includes a mixed metal material, the barrier layer includes a metal oxide material, and the buffer layer includes a non-ferromagnetic material;

The magnetization direction of the first ferromagnetic layer is a fixed direction, and the second ferromagnetic layer forms a ferromagnetic coupling or an antiferromagnetic coupling with the third ferromagnetic layer.

Among them, the use of three ferromagnetic layers increases the volume of the ferromagnetic layer and improves the thermal stability of the MTJ. The SOT is used to realize the reversal of the magnetization direction of the third ferromagnetic layer. Since the magnetization direction of the SOT and the third ferromagnetic layer are different Collinear, fast flipping speed, when writing data, the write current does not need to pass through the MTJ, which reduces the possibility of aging or breakdown of the barrier layer, thereby improving the reliability of the MTJ, and because the write current does not need to pass through the MTJ, it can reduce write current, thereby reducing power consumption.

Wherein, the MTJ includes a read end, a write end and a common end, the read end is located on the first ferromagnetic layer, the write end is located at one end of the heavy metal layer, and the common end is located at the other end of the heavy metal layer;

Writing data into the MTJ when one of the common terminal and the writing terminal is supplied with a high voltage, and the other is supplied with a low voltage, and the reading terminal is disconnected;

When one of the common terminal and the read terminal has a high voltage and the other one has a low voltage, and the write terminal is disconnected, data is read from the MTJ.

The first aspect is implemented in conjunction with the present invention. In the first implementation manner of the first aspect of the embodiment of the present invention, the interface perpendicular magnetic anisotropy PMA of the second ferromagnetic layer is greater than the interface PMA of the third ferromagnetic layer .

Wherein, since the coercive field of the second ferromagnetic layer is larger, the data stored in the second ferromagnetic layer is more stable, which can improve the stability of data storage.

In combination with the first implementation of the first aspect of the present invention or the first implementation of the first aspect of the embodiments of the present invention, in the second implementation of the second aspect of the embodiments of the present invention, the mixed metal material includes cobalt-iron, cobalt-iron-boron , cobalt platinum, nickel iron, cobalt palladium in one or more combinations.

With reference to the second implementation manner of the first aspect of the embodiments of the present invention, in the third implementation manner of the second aspect of the embodiments of the present invention, the MTJ further includes a non-ferromagnetic layer located on the Between the heavy metal layer and the third ferromagnetic layer, the non-ferromagnetic layer is made of the metal oxide material, and the thickness of the non-ferromagnetic layer is 0.1-1 nm.

Among them, adding a non-ferromagnetic layer between the heavy metal layer and the third ferromagnetic layer is equivalent to the role of the barrier layer, which can make the third ferromagnetic layer produce a lattice structure, thereby enhancing the PMA of the third ferromagnetic layer. , reducing the write current.

In combination with implementing the first aspect of the present invention or the first implementation manner of the first aspect of the embodiments of the present invention, in a fourth implementation manner of the second aspect of the embodiments of the present invention, the mixed metal material includes a Heusler alloy.

Among them, the use of Heusler alloy can produce a lattice structure without the need for a non-ferromagnetic layer between the heavy metal layer and the third ferromagnetic layer, which can reduce the aging or breakdown of the barrier layer, improve device reliability, increase the reading speed, and reduce Barrier tunneling current, improving thermal stability and integration.

With reference to the fourth implementation manner of the first aspect of the embodiments of the present invention, in the fifth implementation manner of the second aspect of the embodiments of the present invention, the MTJ further includes a non-ferromagnetic layer located on the Between the heavy metal layer and the third ferromagnetic layer, the non-ferromagnetic layer is the first metal material, and the first metal material includes any one of copper, gold, ruthenium, tantalum, and hafnium, so The thickness of the non-ferromagnetic layer is 0.1-2 nm.

Among them, after adding a non-ferromagnetic layer to the MTJ, the PMA can be enhanced and the write current can be reduced.

In combination with the implementation of the first aspect of the present invention or any one of the first to fifth implementations of the first aspect of the embodiments of the present invention, in the sixth implementation of the second aspect of the embodiments of the present invention, the metal oxide Materials include magnesia or alumina.

Among them, the barrier layer adopts metal oxide, which is used to generate tunneling effect and can improve TMR. The non-ferromagnetic layer adopts metal oxide, which can make the third ferromagnetic layer generate a lattice structure, thereby enhancing the PMA of the third ferromagnetic layer and reducing the writing current.

In combination with the first aspect of the present invention or any one of the first to sixth implementations of the first aspect of the embodiments of the present invention, in the seventh implementation of the second aspect of the embodiments of the present invention, the first The ferromagnetic layer further includes a second metal material, and the second metal material includes any one of tantalum, ruthenium, and tungsten.

Wherein, adding the second metal material to the first ferromagnetic layer can improve the stability of the magnetization direction of the first ferromagnetic layer.

In combination with the implementation of the first aspect of the present invention or any one of the first to seventh implementations of the first aspect of the embodiments of the present invention, in the eighth implementation of the second aspect of the embodiments of the present invention, the buffer layer The thickness is 0.1-1 nm, and the non-ferromagnetic material includes any one of tantalum, ruthenium, tungsten, vanadium, copper, niobium, iridium, molybdenum, and chromium.

Wherein, when the material of the buffer layer is any one of tantalum, ruthenium, tungsten, vanadium, copper, niobium, iridium, molybdenum, chromium, the second ferromagnetic layer and the first ferromagnetic layer can be controlled by adjusting the thickness and material of the buffer layer. The three ferromagnetic layers form ferromagnetic coupling or antiferromagnetic coupling to realize the reversal speed of the magnetization direction of the second ferromagnetic layer (storage layer) and increase the writing speed.

In combination with the first aspect of the present invention or any one of the first to eighth implementations of the first aspect of the embodiments of the present invention, in the ninth implementation of the second aspect of the embodiments of the present invention, the first The thickness of the ferromagnetic layer is 1 to 20 nm.

Wherein, the thickness of the first ferromagnetic layer is 1-20 nm, so that the magnetization direction of the first ferromagnetic layer can be fixed, and the stability of data storage can be improved.

In combination with the implementation of the first aspect of the present invention or any one of the first to ninth implementations of the first aspect of the embodiments of the present invention, in the tenth implementation of the second aspect of the embodiments of the present invention, the barrier The thickness of the layer is 0.1 to 2 nm.

Wherein, the thickness of the barrier layer is 0.1-2nm, which can increase the TMR value and improve the reading reliability.

In combination with the first aspect of the present invention or any one of the first to tenth implementation manners of the first aspect of the embodiments of the present invention, in the eleventh implementation manner of the second aspect of the embodiments of the present invention, the first The thickness of the second ferromagnetic layer is 0.2-3 nm, and the thickness of the third ferromagnetic layer is 0.2-3 nm.

Wherein, the thickness of the second ferromagnetic layer 303 is 0.2-3 nm, and the thickness of the third ferromagnetic layer 305 is 0.2-3 nm, which can make it easier to reverse the magnetization direction of the third ferromagnetic layer and realize low power consumption writing. By flipping the second ferromagnetic layer through ferromagnetic coupling or antiferromagnetic coupling, the second ferromagnetic layer is used to store data more stably.

In combination with the first aspect of the present invention or any one of the first to eleventh implementations of the first aspect of the embodiments of the present invention, in the twelfth implementation of the second aspect of the embodiments of the present invention, the The material of the heavy metal layer includes one or more combinations of tantalum, ruthenium, aluminum, platinum, tungsten or copper, and the thickness of the heavy metal layer is 5-200 nm.

Among them, the heavy metal layer has a larger Hall angle, and the current passing through the heavy metal layer can generate a larger spin-orbit moment SOT, which helps to achieve low power consumption flipping.

In combination with the first aspect of the present invention or any one of the first to twelfth implementation manners of the first aspect of the embodiments of the present invention, in the thirteenth implementation manner of the second aspect of the embodiments of the present invention, the The shape of the MTJ is one of rectangular, circular, or elliptical.

The second aspect of the embodiment of the present invention provides a magnetic memory, including the MTJ in any implementation manner of the first aspect of the present invention and a switch tube corresponding to the MTJ, wherein:

Each of the MTJs includes a read end, a write end and a common end, the read end is located on the first ferromagnetic layer of the MTJ, the write end is located on the heavy metal layer of the MTJ One end, the common end is located at the other end of the heavy metal layer of the MTJ, the common end of the MTJ is connected to the bit line BL through a switch tube, the read end of the MTJ is connected to the read line RL, and the read end of the MTJ is connected to the read line RL. The write end is connected to the source line SL;

When the switch is turned on, if one of the BL and the SL is applied with a high voltage and the other is applied with a low voltage, data is written into the MTJ;

When the switch is turned on, if one of the BL and the RL is applied with a high voltage and the other is applied with a low voltage, data is read from the MTJ.

Among them, the use of SOT can increase the reversal speed of the magnetization direction of the ferromagnetic layer in the MTJ, increase the read and write speed, and the read and write paths are independent. The write current does not need to pass through the barrier layer in the MTJ, which reduces the write power consumption and the MTJ The possibility of aging or breakdown of the barrier layer in the magnetic memory improves the reliability of the magnetic memory.

In the embodiment of the present invention, the magnetic tunnel junction MTJ includes a first ferromagnetic layer, a barrier layer, a second ferromagnetic layer, a buffer layer, a third ferromagnetic layer and a heavy metal layer, wherein: the first ferromagnetic layer, the second ferromagnetic layer Both the magnetic layer and the third ferromagnetic layer are mixed metal materials, the barrier layer is a metal oxide material, and the buffer layer is a non-ferromagnetic material; the magnetization direction of the first ferromagnetic layer is a fixed direction, and the second ferromagnetic layer and the second ferromagnetic layer are The three ferromagnetic layers form ferromagnetic coupling or antiferromagnetic coupling, and the interface perpendicular magnetic anisotropy PMA of the second ferromagnetic layer is greater than that of the third ferromagnetic layer. When a current is injected into the heavy metal layer, electrons with different spin directions in the heavy metal layer move in the direction perpendicular to the current, and accumulate at the bottom of the heavy metal layer and at the interface between the heavy metal layer and the third ferromagnetic layer, forming a vertical spin current. , so that the spin-orbit moment SOT is generated between the heavy metal layer and the third ferromagnetic layer; the direction of the spin-orbit moment SOT generated between the third ferromagnetic layer and the heavy metal layer is different from the magnetization direction of the third ferromagnetic layer Collinear, the magnetization direction of the third ferromagnetic layer is quickly flipped under the action of the spin-orbit moment SOT, because the second ferromagnetic layer and the third ferromagnetic layer form ferromagnetic coupling or antiferromagnetic coupling, which leads to the second The magnetization direction of the ferromagnetic layer (storage layer, also referred to as free layer) is flipped rapidly, which can increase the speed of flipping the magnetization direction of the storage layer in the MTJ.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the accompanying drawings that are required in the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only For some embodiments of the present invention, those skilled in the art can also obtain other drawings based on these drawings without creative work.

Fig. 1 is a schematic structural diagram of a traditional MTJ disclosed in the prior art;

Fig. 2 is a schematic structural diagram of a double barrier layer MTJ disclosed in the prior art;

Fig. 3 is a schematic structural diagram of an MTJ disclosed in an embodiment of the present invention;

Fig. 4 is a schematic structural diagram of another MTJ disclosed in an embodiment of the present invention;

Fig. 5 is a schematic structural diagram of another MTJ disclosed in an embodiment of the present invention;

FIG. 6 is a schematic structural diagram of another MTJ disclosed in an embodiment of the present invention;

FIG. 7 is a schematic structural diagram of a magnetic memory disclosed by an embodiment of the present invention.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

Please refer to FIG. 1 . FIG. 1 is a schematic structural diagram of a traditional MTJ disclosed in the prior art. The MTJ shown in Figure 1 includes a first ferromagnetic layer 101, a barrier layer 102, and a second ferromagnetic layer 103, wherein the magnetization direction of the first ferromagnetic layer 101 is fixed and is a reference layer, and the second ferromagnetic layer The magnetization direction of 103 can be parallel or antiparallel to the reference layer, which is a storage layer, also called a free layer. When the magnetization directions of the storage layer 103 and the reference layer 101 are _antiparallel , as shown in FIG. As shown in b), the MTJ presents a low-resistance state R _p . When storing information, when the MTJ presents a low-resistance state, it represents the binary data "0", and when the MTJ presents a high-resistance state, it represents the binary data "1". The difference between high and low resistance states is described by Tunnel Magnetoresistance (TMR), TMR=(R _ap −R _p )/R _p , the larger the TMR, the higher the reading reliability. The magnetic memory changes the magnetization direction of the storage layer through the spin-transfer torque (English: Spin-Transfer Torque, referred to as STT). When the current passes through the MTJ, the STT and the magnetization direction of the storage layer 103 are collinear, and need to be disturbed to achieve flipping, causing the storage layer The magnetization direction reversal of 103 is slower.

When the magnetization direction of the storage layer 103 is antiparallel to the reference layer 101, as shown in FIG. From bottom to top, electrons with a downward spin direction in the reference layer 101 (such as electron a1 in Figure 1) are different from the magnetization direction of the reference layer 101, and the electrons with a downward spin direction in the reference layer 101 cannot pass through the reference layer 101 ( As shown in Figure 1, the electron a1 returns to the reference layer 101 via the trajectory s1), while the electrons in the reference layer 101 with upward spin directions (such as the electrons a2 and a3 in Figure 1) have the same magnetization direction as the reference layer 101 , the electrons whose spin direction is upward in the reference layer 101 pass through the barrier layer 102 and act on the storage layer 103 (as electrons a2 and a3 in Figure 1 pass through the barrier layer 102 through the track s2 and enter the storage layer 103), to Make the spin of the electrons passing through the reference layer 101 and the magnetic moment of the electrons in the storage layer 103 generate a spin-transfer torque (English: Spin-Transfer Torque, STT for short), and make the electrons passing through the reference layer 101 and the storage layer 103 The electrons in the reference layer 101 precess and gradually reverse the magnetization direction of the storage layer 103 (the magnetization direction of the storage layer 103 is gradually reversed from downward to upward). When the number of electrons passing through the reference layer 101 is sufficient, the storage layer can be The magnetic moment direction of the electrons in 103 is "assimilated" (as shown in figure (a), the magnetization direction of the storage layer 103 gradually changes from downward to upward), so that the magnetic moment direction of the electrons in the storage layer 103 is the same as that in the reference layer 101 The directions of the magnetic moments of the electrons are the same, and a state in which the magnetization directions of the storage layer 103 and the reference layer 101 are consistent is realized. Since the STT is parallel to the initial magnetic moment direction of the electrons in the storage layer 103 , disturbance is required to reverse the magnetization direction of the storage layer 103 , and the precession time is relatively long, resulting in slow read and write speeds.

When the magnetization direction of the storage layer 103 is parallel to that of the reference layer 101, as shown in FIG. The electrons whose spin direction is up in the storage layer 103 (such as electrons b2 and b3 in Figure 1) pass through the barrier layer 102 to reach the reference layer 101 due to the same magnetization direction as the reference layer 101, and the spin direction in the storage layer 103 Downward electrons (such as electron b1 in Figure 1) are different from the magnetization direction of the reference layer 101, so they cannot reach the reference layer 101 and are reflected back. The spin of the reflected electrons and the magnetic moment of the electrons in the storage layer 103 produce STT, make the reflected electrons and the electrons in the storage layer 103 precess, gradually flip the magnetization direction of the storage layer 103 (the magnetization direction of the flip storage layer 103 is gradually flipped from upward to downward), when the amount of electrons reflected back is sufficient For a long time, the magnetic moment direction of the electrons in the storage layer 103 can be "assimilated" (as shown in figure (b), the magnetization direction of the storage layer 103 gradually changes from upward to downward), so that the magnetic moment of the electrons in the storage layer 103 The direction of the moment is different from that of the electrons in the reference layer 101 , so that the storage layer 103 and the reference layer 101 have opposite magnetization directions. Similarly, since the STT is parallel to the initial magnetic moment direction of the electrons in the storage layer 103 , disturbance is required to reverse the magnetization direction of the storage layer 103 , and the precession time is long, resulting in slow read and write speeds.

Please refer to FIG. 2 . FIG. 2 is a schematic structural diagram of a double barrier layer MTJ disclosed in the prior art. As shown in FIG. 2 , it includes a first ferromagnetic layer 201 , a first barrier layer 202 , a second ferromagnetic layer 203 , a buffer layer 204 , a third ferromagnetic layer 205 and a second barrier layer 206 from bottom to top.

Compared with the traditional MTJ shown in Figure 1, the double barrier layer MTJ in Figure 2 has one more buffer layer, one ferromagnetic layer and one barrier layer, and the double barrier layer MTJ shown in Figure 2 is used , increasing the volume of the ferromagnetic layer can improve the interfacial anisotropy, and compared with conventional MTJ, the thermal stability is improved. However, since the magnetization direction reversal principle of the storage layer of the double barrier layer MTJ is the same as that of the traditional MTJ, the magnetization direction reversal of the storage layer is realized through STT, the precession time is still very long, and the read and write speed is still slow.

It should be noted that, in the MTJ shown in FIG. 1 and FIG. 2, in the process of reading and writing, the current needs to pass through the entire MTJ. For example, in FIG. 1, the current needs to flow through the second ferromagnetic layer 103, the potential barrier layer 102 and the first ferromagnetic layer 101; in FIG. 2, the current needs to flow through the second barrier layer 206, the third ferromagnetic layer 205, the buffer layer 204, the second ferromagnetic layer 203, the first barrier layer 202 and the first ferromagnetic layer 201 .

The embodiment of the invention discloses a magnetic tunnel junction and a magnetic memory, which can increase the inversion speed of the magnetization direction of the storage layer in the magnetic tunnel junction. Each will be described in detail below.

Please refer to FIG. 3 . FIG. 3 is a schematic structural diagram of an MTJ disclosed in an embodiment of the present invention. As shown in FIG. 3 , it includes a first ferromagnetic layer 301, a barrier layer 302, a second ferromagnetic layer 303, a buffer layer 304, a third ferromagnetic layer 305 and a heavy metal layer 306 from top to bottom, wherein:

The first ferromagnetic layer 301, the second ferromagnetic layer 303 and the third ferromagnetic layer 305 all include a mixed metal material, the barrier layer 302 includes a metal oxide material, and the buffer layer 304 includes a non-ferromagnetic material;

The magnetization direction of the first ferromagnetic layer 301 is a fixed direction, and the second ferromagnetic layer 303 and the third ferromagnetic layer 305 form a ferromagnetic coupling or an antiferromagnetic coupling.

In the embodiment of the present invention, the first ferromagnetic layer 301, the second ferromagnetic layer 303 and the third ferromagnetic layer 305 all include a mixed metal material, the mixed metal material is a ferromagnetic material; the barrier layer 302 is a metal oxide material, It is a non-ferromagnetic material; the buffer layer 304 is a non-ferromagnetic material, which can be a non-ferromagnetic metal material; the first ferromagnetic layer 301 is a reference layer, and the magnetization direction remains unchanged, so the magnetization direction of the first ferromagnetic layer 301 is The fixed direction, such as fixed up or fixed down, can be controlled to form ferromagnetic coupling or antiferromagnetic coupling between the second ferromagnetic layer 303 and the third ferromagnetic layer 305 by adjusting the thickness and material of the buffer layer 304 .

When a current is injected into the heavy metal layer 306, electrons with different spin directions in the heavy metal layer 306 move to the vertical direction of the current to generate a spin current, which will cause the spin accumulation of the heavy metal layer 306, due to the barrier layer 302, the second The structure inversion asymmetry formed by the second ferromagnetic layer 303, the buffer layer 304, the third ferromagnetic layer 305 and the heavy metal layer 306 in the vertical direction will make the spin accumulation generate a spin orbit acting on the third ferromagnetic layer 305 Torque (English: Spin-Orbit Torque, referred to as SOT), and the magnetization direction of SOT and the third ferromagnetic layer 305 is not collinear, SOT acts directly on the third ferromagnetic layer 305, which is similar to the MTJ in Figure 1 or Figure 2 Compared with this, the disturbance process can be reduced, and the magnetization direction of the third ferromagnetic layer 305 can be flipped at a faster speed. Ferromagnetic coupling is: an external magnetic field is required to make the SOT reverse deterministically, and the magnetization directions of the second ferromagnetic layer 303 and the third ferromagnetic layer 305 are the same; antiferromagnetic coupling is: an internal effective magnetic field is generated by exchanging bias without applying an external The magnetic field can realize the deterministic switching of the SOT, and the magnetization directions of the second ferromagnetic layer 303 and the third ferromagnetic layer 305 are opposite. Preferably, the second ferromagnetic layer 303 and the third ferromagnetic layer 305 form an antiferromagnetic coupling. Compared with the ferromagnetic coupling, the antiferromagnetic coupling does not need to apply an external magnetic field, which saves space and can improve integration.

MTJ can use traditional ion beam epitaxy, atomic layer deposition or magnetron sputtering methods to plate each layer of material on the substrate in order from bottom to top, and then process nano-devices through photolithography, etching, etc. Prepare.

As shown in Figure 3 (a), the first ferromagnetic layer 301 is a reference layer, the magnetization direction of the first ferromagnetic layer 301 is fixed and is "vertically upward", the second ferromagnetic layer 303 is a storage layer, and the second ferromagnetic layer 303 is a storage layer. The initial magnetization direction of the ferromagnetic layer 303 is "vertical downward", at this time, the data stored by the MTJ is "1", and the third ferromagnetic layer 305 is a flipping layer, because the second ferromagnetic layer 303 and the third ferromagnetic layer 305 An antiferromagnetic coupling is formed, and the initial magnetization direction of the third ferromagnetic layer 305 is "vertically upward". When it is necessary to write data "0" into the MTJ, a positive current is injected into the heavy metal layer 306, and electrons with different spin directions in the heavy metal layer 306 (such as electrons a1, a2 with upward spins in Figure 3, spin The downward electrons a3, a4) move to the vertical direction of the current to generate spin current, and the accumulated spin current at the interface between the heavy metal layer 306 and the third ferromagnetic layer 305 will cause the spin accumulation of the heavy metal layer 306 (as shown in Figure 3 The spin accumulation of the electrons a1 and a2 with upward spin in the middle), the spin accumulation produces the SOT acting on the third ferromagnetic layer 305, and the direction of the SOT is kept perpendicular to the magnetization direction of the third ferromagnetic layer 305, so that The magnetization direction of the third ferromagnetic layer 305 rotates counterclockwise until the magnetization direction of the third ferromagnetic layer 305 changes from the initial "vertical upward" to parallel to the current direction, and at this time, the injection of positive write current into the heavy metal layer 306 is stopped. Since the second ferromagnetic layer 303 forms an antiferromagnetic coupling with the third ferromagnetic layer 305, an intrinsic effective magnetic field is generated by exchanging bias, so that the magnetization direction of the third ferromagnetic layer 305 is deterministically changed from parallel to the current direction. For "vertical downward", the reversal of the magnetization direction of the third ferromagnetic layer 305 is realized, and the magnetization direction of the second ferromagnetic layer 303 becomes "vertical upward". At this time, the data written in the MTJ changes from "1 " becomes "0". The direction of the SOT is kept perpendicular to the magnetization direction of the third ferromagnetic layer 305, that is, the direction of the SOT is not collinear with the magnetization direction of the third ferromagnetic layer 305, which can reduce the disturbance process compared with the MTJ in Figure 1 or Figure 2 , the magnetization direction reversal speed of the third ferromagnetic layer 305 is fast.

As shown in Figure 3 (b), the first ferromagnetic layer 301 is a reference layer, the magnetization direction of the first ferromagnetic layer 301 is fixed, which is "vertical upward", the second ferromagnetic layer 303 is a storage layer, and the second ferromagnetic layer 303 is a storage layer. The initial magnetization direction of the ferromagnetic layer 303 is "vertical upward". At this time, the data stored by the MTJ is "0", and the third ferromagnetic layer 305 is a flipping layer. Since the second ferromagnetic layer 303 and the third ferromagnetic layer 305 form For antiferromagnetic coupling, the initial magnetization direction of the third ferromagnetic layer 305 is "vertically downward". When it is necessary to write data "1" into the MTJ, a negative write current is injected into the heavy metal layer 306, and electrons with different spin directions in the heavy metal layer 306 (such as electrons b1 and b2 with downward spin in Fig. The electrons b3, b4) on the spin direction move to the vertical direction of the current to generate a spin current, and the accumulated spin current at the interface between the heavy metal layer 306 and the third ferromagnetic layer 305 will cause the spin accumulation of the heavy metal layer 306 (as shown in Figure 3 The spin accumulation of the electrons b1 and b2 with downward spin in the middle), the spin accumulation produces the SOT acting on the third ferromagnetic layer 305, and the direction of the SOT is kept perpendicular to the magnetization direction of the third ferromagnetic layer 305, so as to Rotate the magnetization direction of the third ferromagnetic layer 305 clockwise until the magnetization direction of the third ferromagnetic layer 305 changes from the initial "vertical downward" to parallel to the current direction, at this time, stop injecting and writing into the heavy metal layer 306 Negative current, because the second ferromagnetic layer 303 forms an antiferromagnetic coupling with the third ferromagnetic layer 305, an intrinsic effective magnetic field is generated by exchanging bias, so that the magnetization direction of the third ferromagnetic layer 305 is determined by being parallel to the current direction The ground becomes "vertical upward", realizes the reversal of the magnetization direction of the third ferromagnetic layer 305, and makes the magnetization direction of the second ferromagnetic layer 303 become "vertical downward". At this time, the data written in the MTJ is from "0" becomes "1". The direction of the SOT is kept perpendicular to the magnetization direction of the third ferromagnetic layer 305, that is, the direction of the SOT is not collinear with the magnetization direction of the third ferromagnetic layer 305, which can reduce the disturbance process compared with the MTJ in Figure 1 or Figure 2 , the magnetization direction reversal speed of the third ferromagnetic layer 305 is fast.

As shown in Figure 3(c), when data needs to be read from the MTJ, a high voltage is applied to the first ferromagnetic layer 301, a low voltage is applied to the left side of the heavy metal layer 306, and the read current is read from the first ferromagnetic layer 301 Flow through the MTJ to the heavy metal layer 306 from top to bottom. Since the read currents of the first ferromagnetic layer 301 and the second ferromagnetic layer are different in parallel and antiparallel states, the current read by the read amplifier is compared with the reference current , to determine the data information stored therein, the reference reference current can be determined according to the first read current for reading data "0" and the second read current for reading data "1", for example, the reference reference current can be set as The average value of the first read current and the second read current, when the current read by the read amplifier is greater than the reference reference current, it is determined that the data read from the MTJ is "0", when the current read by the read amplifier When it is less than the base reference current, it is determined that the data read from the MTJ is "1".

In one embodiment, the interfacial perpendicular magnetic anisotropy PMA of the second ferromagnetic layer 303 is greater than the interfacial PMA of the third ferromagnetic layer 305 .

Because the larger the PMA, the larger the coercive field, the interface PMA of the second ferromagnetic layer 303 is greater than the interface PMA of the third ferromagnetic layer 305, and the coercive field of the second ferromagnetic layer 303 is greater than the coercive field of the third ferromagnetic layer 305. Coercive field, the easier it is to reverse the magnetization direction of the third ferromagnetic layer 305 and realize low power consumption writing, because the larger the coercive field of the second ferromagnetic layer 303, the more stable the data stored in the second ferromagnetic layer 303 , which can improve the stability of data storage.

In one embodiment, the mixed metal material includes one or more combinations of cobalt-iron, cobalt-iron-boron, cobalt-platinum, nickel-iron, and cobalt-palladium.

In the embodiment of the present invention, the mixed metal material may include ferromagnetic materials such as cobalt iron (CoFe), cobalt iron boron (CoFeB), cobalt platinum (CoPt), nickel iron (NiFe), cobalt palladium (CoPd), and may be cobalt iron , cobalt-iron-boron, cobalt-platinum, nickel-iron, and cobalt-palladium in one or more combinations, the composition of various elements in the mixed metal material can be different, for example, the proportion of each element in CoFeB can be different.

Optionally, as shown in FIG. 4, FIG. 4 is a schematic structural diagram of another MTJ disclosed in an embodiment of the present invention. The MTJ in FIG. 4 also includes a non-ferromagnetic layer 307, which is located between the heavy metal layer 306 and the first Between the three ferromagnetic layers 305, the non-ferromagnetic layer 307 is a metal oxide material, and the thickness of the non-ferromagnetic layer 307 is 0.1-1 nm.

When the first ferromagnetic layer 301, the second ferromagnetic layer 303 and the third ferromagnetic layer 305 are mixed metal materials of one or more combinations of cobalt-iron, cobalt-iron-boron, cobalt-platinum, nickel-iron, and cobalt-palladium When, the MTJ also includes a non-ferromagnetic layer 307, and the non-ferromagnetic layer 307 is a metal oxide material, the metal oxide material may include non-ferromagnetic materials such as magnesium oxide and aluminum oxide, and the thickness of the non-ferromagnetic layer 307 is 0.1- 1nm. A layer of non-ferromagnetic layer 307 is added between the heavy metal layer 306 and the third ferromagnetic layer 305, which is equivalent to the role of the barrier layer 304, which can make the third ferromagnetic layer 305 produce a lattice structure, thereby enhancing the third ferromagnetic layer. The PMA of layer 305 reduces the write current.

In one embodiment, the mixed metal material includes Heusler alloys.

In the embodiment of the present invention, the mixed metal material may include Heusler alloy, also known as Heusler alloy. Heusler alloy is a general term for a class of alloys, usually XYZ and _X2YZ , where X, Y, and Z are the periodic table of elements Elements in specific regions, for example, X can be iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), ruthenium (Ru), rhodium (Rh), palladium (Pd) , silver (Ag), cadmium (Cd), iridium (Ir), platinum (Pt), gold (Au); Y can be titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), Yttrium (Y), Zirconium (Zr), Niobium (Nb), Hafnium (Hf), Tantalum (Ta), Gadolinium (Gd), Terbium (Tb), Dysprosium (Dy), Holmium (Ho), Erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu); Z can be aluminum (Al), silicon (Si), gallium (Ga), germanium (Ge), arsenic (As ), indium (In), tin (Sn), antimony (Sb), thallium (Tl), lead (Pb), bismuth (Bi). Common Heusler alloys can include: Cu ₂ MnAl, Cu ₂ MnIn, Cu ₂ MnSn, Ni ₂ MnAl, Ni ₂ MnIn, Ni ₂ MnSn, Ni ₂ MnSb, Ni ₂ MnGa, Co ₂ MnAl, Co ₂ MnSi, Co ₂ MnGa , Co ₂ MnGe, Pd ₂ MnAl, Pd ₂ MnIn, Pd ₂ MnSn, Pd ₂ MnSb, CoFeSi, CoFeAl, Mn ₂ VGa, Co ₂ FeGe, etc. Heusler alloy has the following advantages: (1), high spin polarizability, can improve the magnetic tunneling resistance (Tunnel Magnetoresistance, TMR) of MTJ, for example, NiMnSb can obtain 100% spin polarizability; (2), high PMA; (3), low magnetic damping coefficient, can reduce the write current of MTJ, and the magnetic damping coefficient α can be as low as 0.001; (4), high Curie temperature, using Heusler alloy, can maintain iron in a large temperature range Magnetism helps MTJ to work in a larger temperature range; (5), the lattice mismatch is small, and the lattice mismatch with the barrier layer 402 is small. For magnesium oxide (MgO), MgO and Co ₂ The lattice mismatch of FeAl is small and easy to manufacture. Using Heusler alloy, without the non-ferromagnetic layer 307 between the heavy metal layer 306 and the third ferromagnetic layer 305, a lattice structure can be produced, which can reduce the aging or breakdown of the barrier layer 302, improve device reliability, and reduce the RA value ( The RA value is the product of the resistance value and the cross-sectional area of the MTJ. Reducing the RA value can increase the reading speed), increase the reading speed, reduce the barrier tunneling current, and improve thermal stability and integration.

Optionally, as shown in FIG. 5, FIG. 5 is a schematic structural diagram of another MTJ disclosed in an embodiment of the present invention. The MTJ in FIG. 5 also includes a non-ferromagnetic layer 307, which is located between the heavy metal layer 306 and the Between the third ferromagnetic layer 305, the non-ferromagnetic layer 307 is the first metal material, the first metal material comprises any one in copper, gold, ruthenium, tantalum, hafnium, and the thickness of the non-ferromagnetic layer 307 is 0.1～ 2nm.

When the first ferromagnetic layer 301, the second ferromagnetic layer 303 and the third ferromagnetic layer 305 are all Heussler alloys, the MTJ can also include a non-ferromagnetic layer 307, and the non-ferromagnetic layer 307 is the first metal material , the first metal material includes any one of copper, gold, ruthenium, tantalum, and hafnium. After the non-ferromagnetic layer 307 is added, the PMA can be enhanced and the writing current can be reduced.

In one embodiment, the metal oxide material includes magnesium oxide or aluminum oxide.

The barrier layer 302 is made of metal oxide, which is used to generate a tunneling effect, which can improve TMR. The non-ferromagnetic layer 307 is made of metal oxide, which can make the third ferromagnetic layer 305 have a lattice structure, thereby enhancing the PMA of the third ferromagnetic layer 305 and reducing the writing current. Preferably, the barrier layer 302 can be made of magnesium oxide. When the barrier layer 302 is made of magnesium oxide, and the first ferromagnetic layer 301 and the second ferromagnetic layer 303 are made of Heusler alloy, the lattice mismatch is small and the lattice defects less, easy to synthesize.

In one embodiment, the first ferromagnetic layer 301 further includes a second metal material, and the second metal material includes any one of tantalum, ruthenium, and tungsten.

In addition to the mixed metal material, the first ferromagnetic layer 301 may also include a second metal material, and the first ferromagnetic layer 301 itself may include three layers, for example, as shown in FIG. 6 , which is a disclosure of an embodiment of the present invention. The structure schematic diagram of another MTJ, the upper layer and the lower layer in Fig. 6 are both cobalt-platinum (CoPt) mixed metal materials, and the middle layer is any one of tantalum, ruthenium, and tungsten. Implementing the MTJ shown in FIG. 6 can improve the stability of the magnetization direction of the first ferromagnetic layer 301 .

In one embodiment, the thickness of the buffer layer 304 is 0.1-1 nm, and the non-ferromagnetic material includes any one of tantalum, ruthenium, tungsten, vanadium, copper, niobium, iridium, molybdenum, and chromium.

The buffer layer 304 is made of non-ferromagnetic materials, such as tantalum, ruthenium, tungsten, vanadium, copper, niobium, iridium, molybdenum, chromium and the like. By adjusting the thickness and material of the buffer layer 304 , the second ferromagnetic layer 303 and the third ferromagnetic layer 305 can be controlled to form ferromagnetic coupling or antiferromagnetic coupling. E.g:;

The antiferromagnetic coupling range of tantalum Ta is 0.5nm-0.9nm, and the maximum antiferromagnetic coupling is reached at 0.7nm; the ferromagnetic coupling range is 0.1nm-0.5nm;

The antiferromagnetic coupling range of ruthenium Ru is 0.1nm-0.6nm, and the maximum antiferromagnetic coupling is reached at 0.3nm; the ferromagnetic coupling range is 0.6nm-1.0nm;

The antiferromagnetic coupling range of tungsten W is 0.25nm-0.85nm, and the maximum antiferromagnetic coupling is reached at 0.55nm; the ferromagnetic coupling range is 0.1nm-0.5nm;

The antiferromagnetic coupling range of vanadium V is 0.6nm-1.0nm, and the antiferromagnetic coupling reaches the maximum at 0.9nm; the ferromagnetic coupling range is 0.1nm-0.6nm;

The antiferromagnetic coupling range of copper Cu is 0.5nm-1.0nm, and the maximum antiferromagnetic coupling is reached at 0.8nm; the ferromagnetic coupling range is 0.1nm-0.5nm;

The antiferromagnetic coupling range of niobium Nb is 0.7nm-1.0nm, and the antiferromagnetic coupling reaches the maximum at 0.95nm; the ferromagnetic coupling range is 0.1nm-0.7nm;

The antiferromagnetic coupling interval of iridium Ir is 0.1nm-0.7nm, and the antiferromagnetic coupling reaches the maximum at 0.4nm; the ferromagnetic coupling interval is 0.7nm-1.0nm;

The antiferromagnetic coupling range of molybdenum Mo is 0.22nm-0.82nm, and the antiferromagnetic coupling reaches the maximum at 0.52nm;

The antiferromagnetic coupling range of chromium Cr is 0.1nm-1nm, and the antiferromagnetic coupling reaches the maximum at 0.7nm;

Since the antiferromagnetic coupling does not require an external magnetic field, the antiferromagnetic coupling is preferred in the embodiment of the present invention.

In one embodiment, the thickness of the first ferromagnetic layer 301 is 1-20 nm. The magnetization direction of the first ferromagnetic layer 301 can be fixed, which can improve data storage stability.

In one embodiment, the barrier layer 302 has a thickness of 0.1-2 nm. Preferably, the barrier layer 302 has a thickness of 1 nm, and increasing the thickness of the barrier layer 302 can increase the TMR value and improve read reliability.

In one embodiment, the thickness of the second ferromagnetic layer 303 is 0.2-3 nm, and the thickness of the third ferromagnetic layer 305 is 0.2-3 nm. The magnetization direction of the third ferromagnetic layer 305 can be reversed more easily to achieve low power consumption writing, and the second ferromagnetic layer 303 can be reversed through ferromagnetic coupling or antiferromagnetic coupling, so that the second ferromagnetic layer 303 is more stable Storing data.

In one embodiment, the material of the heavy metal layer 306 includes one or more combinations of tantalum, ruthenium, aluminum, platinum, tungsten or copper, and the thickness of the heavy metal layer 306 is 5-200 nm. With a larger Hall angle, the current passing through the heavy metal layer 306 can generate a larger spin-orbit moment SOT, which helps to achieve low power consumption switching.

In one embodiment, the shape of the MTJ is one of rectangular, circular or elliptical.

By implementing the MTJ shown in Figure 3, compared with the MTJ shown in Figure 1, the volume of the ferromagnetic layer is increased, the interfacial anisotropy can be improved, and the thermal stability is improved compared with the MTJ shown in Figure 1. Compared with the MTJ shown in FIG. 1 and FIG. 2, the MTJ shown in FIG. 3 adopts SOT to realize the reversal of the magnetization direction of the third ferromagnetic layer 305. Since the magnetization direction of the SOT and the third ferromagnetic layer 305 are not collinear, The flipping speed is fast. When writing data, the write current does not need to pass through the MTJ, which reduces the possibility of barrier layer aging or breakdown, thereby improving the reliability of the MTJ. At the same time, because the write current does not need to pass through the MTJ, the write current can be reduced. , thereby reducing power consumption.

Please refer to FIG. 7. FIG. 7 is a schematic structural diagram of a magnetic memory disclosed in an embodiment of the present invention. As shown in FIG. 7, the magnetic memory includes multiple MTJs and multiple switch tubes as shown in FIG. 3, wherein:

Each MTJ includes a read terminal RP, a write terminal WP and a common terminal GND, the read terminal RP is located on the first ferromagnetic layer 301 of the MTJ, the write terminal WP is located at one end of the heavy metal layer 306 of the MTJ, and the common terminal GND Located at the other end of the heavy metal layer 306 of the MTJ, the common terminal GND of the MTJ is connected to the bit line BL through a switch tube, the reading terminal RP of the MTJ is connected to the reading line RL, and the writing terminal WP of the MTJ is connected to the source line SL;

When the switch is turned on, if one of BL and SL is applied with a high voltage and the other is applied with a low voltage, data is written into the MTJ;

When the switch is turned on, if one of BL and RL is applied with a high voltage and the other is applied with a low voltage, the data is read from the MTJ.

In the embodiment of the present invention, the magnetic memory may include Magnetic Random Access Memory (English: Magnetic Random Access Memory, MRAM for short). The magnetic memory includes a plurality of MTJs and a plurality of switch tubes T corresponding to the above-mentioned multiple MTJs, and the switch tube T may be a metal-oxide-semiconductor field-effect transistor (English: Metal-Oxide-Semiconductor Field-Effect Transistor, MOSFET, MOS tube for short) , MTJ0, MTJ1, MTJ2, MTJ3...etc in Fig. 7. The common terminal GND of each MTJ is connected to the bit line BL through the switch tube, for example, the common terminal GND0 of MTJ0 is connected to the bit line BL0 through the switch tube T0, the common terminal GND1 of MTJ1 is connected to the bit line BL1 through the switch tube T1, and the common terminal of MTJ2 GND2 is connected to the bit line BL2...etc. through the switch tube T2. The reading end RP of each MTJ is connected to the reading line RL, for example, the reading end RP0 of MTJ0 is connected to the reading line RL0, the reading end RP1 of MTJ1 is connected to the reading line RL1, and the reading end RP2 of MTJ2 is connected to the reading line RL2...etc. The write terminal WP of each MTJ is connected to the source line SL, for example, the write terminal WP0 of MTJ0 is connected to the source line SL0, the write terminal WP1 of MTJ1 is connected to the source line SL1, and the write terminal WP2 of MTJ2 is connected to the source line SL2... ...Wait.

When writing data into the magnetic memory, for example, if it is necessary to write data "0" into MTJ0, turn on the switch tube T0 (if the switch tube T0 is a MOS tube, apply a high level to WL0 to make the switch tube T0 conduction), apply high voltage to SL0, apply low voltage to BL0, and disconnect RL0; if you need to write data "1" into MTJ0, turn on switch T0, apply low voltage to SL0, apply high voltage to BL0, and disconnect RL0 open. When writing data into the MTJ, the current does not need to pass through the MTJ, but only through the heavy metal layer of the MTJ, so the write power consumption is reduced, the possibility of aging or breakdown of the barrier layer in the MTJ is reduced, and the reliability of the magnetic memory is improved. .

When reading data from the magnetic memory, for example, if you need to read the data in MTJ0, turn on the switch tube T0, apply a high voltage to RL0, apply a low voltage to BL0, turn off SL0, and read the data in MTJ0 through the read amplifier. Current, the current read by the read amplifier is compared with the reference reference current to judge the data information stored in it, for example, when the current read by the read amplifier is greater than the reference reference current, it is determined that the data stored in MTJ0 is " 0", when the current read by the sense amplifier is less than the reference current, it is determined that the data stored in MTJ0 is "1".

Implementing the magnetic memory shown in Figure 7, using SOT, can increase the inversion speed of the magnetization direction of the ferromagnetic layer in the MTJ, improve the read and write speed, the read and write paths are independent, and the write current does not need to pass through the barrier layer in the MTJ, which reduces the write time. The input power consumption is reduced, the possibility of aging or breakdown of the barrier layer in the MTJ is reduced, and the reliability of the magnetic memory is improved.

A magnetic tunnel junction and a magnetic memory disclosed in the embodiments of the present invention have been described above in detail. In this paper, specific examples are used to illustrate the principle and implementation of the present invention. The descriptions of the above embodiments are only used to help understand the present invention. method and its core idea; at the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation and scope of application. In summary, the content of this specification should not be understood as Limitations on the Invention.

Claims (134)

1. a kind of magnetic tunnel-junction MTJ, which is characterized in that from top to bottom successively include the first ferromagnetic layer, barrier layer, second ferromagnetic Layer, buffer layer, third ferromagnetic layer and heavy metal layer, in which:

First ferromagnetic layer, second ferromagnetic layer and the third ferromagnetic layer include mixed-metal materials, the potential barrier Layer includes metal oxide materials, and the buffer layer includes nonferromagnetic material；The MTJ realizes institute using spin(-)orbit square SOT State the overturning of the direction of magnetization of third ferromagnetic layer；The mixed-metal materials include heusler alloy；

The direction of magnetization of first ferromagnetic layer is fixed-direction, and second ferromagnetic layer and the third ferromagnetic layer form anti-iron Magnetic coupling, the buffer layer with a thickness of 0.1~1nm, the nonferromagnetic material include tantalum, ruthenium, tungsten, vanadium, copper, niobium, iridium, molybdenum, Any one of chromium；

When Injection Current in the heavy metal layer, the different electronics of spin direction is to vertical with electric current in the heavy metal layer Direction is mobile, and the interface accumulation between the heavy metal layer bottom and the heavy metal layer and third ferromagnetic layer, forms respectively Erect spin stream, to generate spin orbital moment SOT between the heavy metal layer and the third ferromagnetic layer；Wherein, described The direction of the spin(-)orbit square SOT generated between third ferromagnetic layer and the heavy metal layer and the magnetization side of the third ferromagnetic layer To not conllinear.

2. MTJ according to claim 1, which is characterized in that the MTJ includes reading end, write-in end and common end, described It reads end to be located on first ferromagnetic layer, said write end is located at one end of the heavy metal layer, and the common end is located at institute State the other end of heavy metal layer；

When a high voltage in the common end and said write end, another adds low-voltage, and the reading end disconnects and connecting When connecing, data are written into the MTJ；

When a high voltage in the common end and the reading end, another adds low-voltage, and said write end disconnects and connecting When connecing, data are read from the MTJ.

3. MTJ according to claim 1, which is characterized in that the interface perpendicular magnetic anisotropic PMA of second ferromagnetic layer Greater than the interface PMA of the third ferromagnetic layer.

4. MTJ according to claim 2, which is characterized in that the interface perpendicular magnetic anisotropic PMA of second ferromagnetic layer Greater than the interface PMA of the third ferromagnetic layer.

5. MTJ according to claim 1, which is characterized in that the MTJ further includes non-ferromagnetic layers, the non-ferromagnetic layers position Between the heavy metal layer and the third ferromagnetic layer, the non-ferromagnetic layers are the first metal material, first metal material Material include any one of copper, gold, ruthenium, tantalum, hafnium, the non-ferromagnetic layers with a thickness of 0.1~2nm.

6. described in any item MTJ according to claim 1~5, which is characterized in that the metal oxide materials include magnesia Or aluminium oxide.

7. described in any item MTJ according to claim 1~5, which is characterized in that first ferromagnetic layer further includes the second metal Material, second metal material include any one of tantalum, ruthenium, tungsten.

8. MTJ according to claim 6, which is characterized in that first ferromagnetic layer further includes the second metal material, described Second metal material includes any one of tantalum, ruthenium, tungsten.

9. described in any item MTJ according to claim 1~5, which is characterized in that first ferromagnetic layer with a thickness of 1~ 20nm。

10. MTJ according to claim 6, which is characterized in that first ferromagnetic layer with a thickness of 1~20nm.

11. MTJ according to claim 7, which is characterized in that first ferromagnetic layer with a thickness of 1~20nm.

12. MTJ according to claim 8, which is characterized in that first ferromagnetic layer with a thickness of 1~20nm.

13. described in any item MTJ according to claim 1~5, which is characterized in that the barrier layer with a thickness of 0.1~2nm.

14. MTJ according to claim 6, which is characterized in that the barrier layer with a thickness of 0.1~2nm.

15. MTJ according to claim 7, which is characterized in that the barrier layer with a thickness of 0.1~2nm.

16. MTJ according to claim 8, which is characterized in that the barrier layer with a thickness of 0.1~2nm.

17. MTJ according to claim 9, which is characterized in that the barrier layer with a thickness of 0.1~2nm.

18. MTJ according to claim 10, which is characterized in that the barrier layer with a thickness of 0.1~2nm.

19. MTJ according to claim 11, which is characterized in that the barrier layer with a thickness of 0.1~2nm.

20. MTJ according to claim 12, which is characterized in that the barrier layer with a thickness of 0.1~2nm.

21. described in any item MTJ according to claim 1~5, which is characterized in that second ferromagnetic layer with a thickness of 0.2~ 3nm, the third ferromagnetic layer with a thickness of 0.2~3nm.

22. MTJ according to claim 6, which is characterized in that second ferromagnetic layer with a thickness of 0.2~3nm, it is described Third ferromagnetic layer with a thickness of 0.2~3nm.

23. MTJ according to claim 7, which is characterized in that second ferromagnetic layer with a thickness of 0.2~3nm, it is described Third ferromagnetic layer with a thickness of 0.2~3nm.

24. MTJ according to claim 8, which is characterized in that second ferromagnetic layer with a thickness of 0.2~3nm, it is described Third ferromagnetic layer with a thickness of 0.2~3nm.

25. MTJ according to claim 9, which is characterized in that second ferromagnetic layer with a thickness of 0.2~3nm, it is described Third ferromagnetic layer with a thickness of 0.2~3nm.

26. MTJ according to claim 10, which is characterized in that second ferromagnetic layer with a thickness of 0.2~3nm, it is described Third ferromagnetic layer with a thickness of 0.2~3nm.

27. MTJ according to claim 11, which is characterized in that second ferromagnetic layer with a thickness of 0.2~3nm, it is described Third ferromagnetic layer with a thickness of 0.2~3nm.

28. MTJ according to claim 12, which is characterized in that second ferromagnetic layer with a thickness of 0.2~3nm, it is described Third ferromagnetic layer with a thickness of 0.2~3nm.

29. MTJ according to claim 13, which is characterized in that second ferromagnetic layer with a thickness of 0.2~3nm, it is described Third ferromagnetic layer with a thickness of 0.2~3nm.

30. MTJ according to claim 14, which is characterized in that second ferromagnetic layer with a thickness of 0.2~3nm, it is described Third ferromagnetic layer with a thickness of 0.2~3nm.

31. MTJ according to claim 15, which is characterized in that second ferromagnetic layer with a thickness of 0.2~3nm, it is described Third ferromagnetic layer with a thickness of 0.2~3nm.

32. MTJ according to claim 16, which is characterized in that second ferromagnetic layer with a thickness of 0.2~3nm, it is described Third ferromagnetic layer with a thickness of 0.2~3nm.

33. MTJ according to claim 17, which is characterized in that second ferromagnetic layer with a thickness of 0.2~3nm, it is described Third ferromagnetic layer with a thickness of 0.2~3nm.

34. MTJ according to claim 18, which is characterized in that second ferromagnetic layer with a thickness of 0.2~3nm, it is described Third ferromagnetic layer with a thickness of 0.2~3nm.

35. MTJ according to claim 19, which is characterized in that second ferromagnetic layer with a thickness of 0.2~3nm, it is described Third ferromagnetic layer with a thickness of 0.2~3nm.

36. MTJ according to claim 20, which is characterized in that second ferromagnetic layer with a thickness of 0.2~3nm, it is described Third ferromagnetic layer with a thickness of 0.2~3nm.

37. described in any item MTJ according to claim 1~5, which is characterized in that the heavy metal layer material include tantalum, ruthenium, One of aluminium, platinum, tungsten or copper or multiple combinations, the heavy metal layer with a thickness of 5~200nm.

38. MTJ according to claim 6, which is characterized in that the heavy metal layer material include tantalum, ruthenium, aluminium, platinum, tungsten or One of copper or multiple combinations, the heavy metal layer with a thickness of 5~200nm.

39. MTJ according to claim 7, which is characterized in that the heavy metal layer material include tantalum, ruthenium, aluminium, platinum, tungsten or One of copper or multiple combinations, the heavy metal layer with a thickness of 5~200nm.

40. MTJ according to claim 8, which is characterized in that the heavy metal layer material include tantalum, ruthenium, aluminium, platinum, tungsten or One of copper or multiple combinations, the heavy metal layer with a thickness of 5~200nm.

41. MTJ according to claim 9, which is characterized in that the heavy metal layer material include tantalum, ruthenium, aluminium, platinum, tungsten or One of copper or multiple combinations, the heavy metal layer with a thickness of 5~200nm.

42. MTJ according to claim 10, which is characterized in that the heavy metal layer material includes tantalum, ruthenium, aluminium, platinum, tungsten Or one of copper or multiple combinations, the heavy metal layer with a thickness of 5~200nm.

43. MTJ according to claim 11, which is characterized in that the heavy metal layer material includes tantalum, ruthenium, aluminium, platinum, tungsten Or one of copper or multiple combinations, the heavy metal layer with a thickness of 5~200nm.

44. MTJ according to claim 12, which is characterized in that the heavy metal layer material includes tantalum, ruthenium, aluminium, platinum, tungsten Or one of copper or multiple combinations, the heavy metal layer with a thickness of 5~200nm.

45. MTJ according to claim 13, which is characterized in that the heavy metal layer material includes tantalum, ruthenium, aluminium, platinum, tungsten Or one of copper or multiple combinations, the heavy metal layer with a thickness of 5~200nm.

46. MTJ according to claim 14, which is characterized in that the heavy metal layer material includes tantalum, ruthenium, aluminium, platinum, tungsten Or one of copper or multiple combinations, the heavy metal layer with a thickness of 5~200nm.

47. MTJ according to claim 15, which is characterized in that the heavy metal layer material includes tantalum, ruthenium, aluminium, platinum, tungsten Or one of copper or multiple combinations, the heavy metal layer with a thickness of 5~200nm.

48. MTJ according to claim 16, which is characterized in that the heavy metal layer material includes tantalum, ruthenium, aluminium, platinum, tungsten Or one of copper or multiple combinations, the heavy metal layer with a thickness of 5~200nm.

49. MTJ according to claim 17, which is characterized in that the heavy metal layer material includes tantalum, ruthenium, aluminium, platinum, tungsten Or one of copper or multiple combinations, the heavy metal layer with a thickness of 5~200nm.

50. MTJ according to claim 18, which is characterized in that the heavy metal layer material includes tantalum, ruthenium, aluminium, platinum, tungsten Or one of copper or multiple combinations, the heavy metal layer with a thickness of 5~200nm.

51. MTJ according to claim 19, which is characterized in that the heavy metal layer material includes tantalum, ruthenium, aluminium, platinum, tungsten Or one of copper or multiple combinations, the heavy metal layer with a thickness of 5~200nm.

52. MTJ according to claim 20, which is characterized in that the heavy metal layer material includes tantalum, ruthenium, aluminium, platinum, tungsten Or one of copper or multiple combinations, the heavy metal layer with a thickness of 5~200nm.

53. MTJ according to claim 21, which is characterized in that the heavy metal layer material includes tantalum, ruthenium, aluminium, platinum, tungsten Or one of copper or multiple combinations, the heavy metal layer with a thickness of 5~200nm.

54. MTJ according to claim 22, which is characterized in that the heavy metal layer material includes tantalum, ruthenium, aluminium, platinum, tungsten Or one of copper or multiple combinations, the heavy metal layer with a thickness of 5~200nm.

55. MTJ according to claim 23, which is characterized in that the heavy metal layer material includes tantalum, ruthenium, aluminium, platinum, tungsten Or one of copper or multiple combinations, the heavy metal layer with a thickness of 5~200nm.

56. MTJ according to claim 24, which is characterized in that the heavy metal layer material includes tantalum, ruthenium, aluminium, platinum, tungsten Or one of copper or multiple combinations, the heavy metal layer with a thickness of 5~200nm.

57. MTJ according to claim 25, which is characterized in that the heavy metal layer material includes tantalum, ruthenium, aluminium, platinum, tungsten Or one of copper or multiple combinations, the heavy metal layer with a thickness of 5~200nm.

58. MTJ according to claim 26, which is characterized in that the heavy metal layer material includes tantalum, ruthenium, aluminium, platinum, tungsten Or one of copper or multiple combinations, the heavy metal layer with a thickness of 5~200nm.

59. MTJ according to claim 27, which is characterized in that the heavy metal layer material includes tantalum, ruthenium, aluminium, platinum, tungsten Or one of copper or multiple combinations, the heavy metal layer with a thickness of 5~200nm.

60. MTJ according to claim 28, which is characterized in that the heavy metal layer material includes tantalum, ruthenium, aluminium, platinum, tungsten Or one of copper or multiple combinations, the heavy metal layer with a thickness of 5~200nm.

61. MTJ according to claim 29, which is characterized in that the heavy metal layer material includes tantalum, ruthenium, aluminium, platinum, tungsten Or one of copper or multiple combinations, the heavy metal layer with a thickness of 5~200nm.

62. MTJ according to claim 30, which is characterized in that the heavy metal layer material includes tantalum, ruthenium, aluminium, platinum, tungsten Or one of copper or multiple combinations, the heavy metal layer with a thickness of 5~200nm.

63. MTJ according to claim 31, which is characterized in that the heavy metal layer material includes tantalum, ruthenium, aluminium, platinum, tungsten Or one of copper or multiple combinations, the heavy metal layer with a thickness of 5~200nm.

64. MTJ according to claim 32, which is characterized in that the heavy metal layer material includes tantalum, ruthenium, aluminium, platinum, tungsten Or one of copper or multiple combinations, the heavy metal layer with a thickness of 5~200nm.

65. MTJ according to claim 33, which is characterized in that the heavy metal layer material includes tantalum, ruthenium, aluminium, platinum, tungsten Or one of copper or multiple combinations, the heavy metal layer with a thickness of 5~200nm.

66. MTJ according to claim 34, which is characterized in that the heavy metal layer material includes tantalum, ruthenium, aluminium, platinum, tungsten Or one of copper or multiple combinations, the heavy metal layer with a thickness of 5~200nm.

67. MTJ according to claim 35, which is characterized in that the heavy metal layer material includes tantalum, ruthenium, aluminium, platinum, tungsten Or one of copper or multiple combinations, the heavy metal layer with a thickness of 5~200nm.

68. MTJ according to claim 36, which is characterized in that the heavy metal layer material includes tantalum, ruthenium, aluminium, platinum, tungsten Or one of copper or multiple combinations, the heavy metal layer with a thickness of 5~200nm.

69. described in any item MTJ according to claim 1~5, which is characterized in that the shape of the MTJ be rectangle, circle or One of ellipse.

70. MTJ according to claim 6, which is characterized in that the shape of the MTJ is rectangle, in round or ellipse It is a kind of.

71. MTJ according to claim 7, which is characterized in that the shape of the MTJ is rectangle, in round or ellipse It is a kind of.

72. MTJ according to claim 8, which is characterized in that the shape of the MTJ is rectangle, in round or ellipse It is a kind of.

73. MTJ according to claim 9, which is characterized in that the shape of the MTJ is rectangle, in round or ellipse It is a kind of.

74. MTJ according to claim 10, which is characterized in that the shape of the MTJ is rectangle, in round or ellipse One kind.

75. MTJ according to claim 11, which is characterized in that the shape of the MTJ is rectangle, in round or ellipse One kind.

76. MTJ according to claim 12, which is characterized in that the shape of the MTJ is rectangle, in round or ellipse One kind.

77. MTJ according to claim 13, which is characterized in that the shape of the MTJ is rectangle, in round or ellipse One kind.

78. MTJ according to claim 14, which is characterized in that the shape of the MTJ is rectangle, in round or ellipse One kind.

79. MTJ according to claim 15, which is characterized in that the shape of the MTJ is rectangle, in round or ellipse One kind.

80. MTJ according to claim 16, which is characterized in that the shape of the MTJ is rectangle, in round or ellipse One kind.

81. MTJ according to claim 17, which is characterized in that the shape of the MTJ is rectangle, in round or ellipse One kind.

82. MTJ according to claim 18, which is characterized in that the shape of the MTJ is rectangle, in round or ellipse One kind.

83. MTJ according to claim 19, which is characterized in that the shape of the MTJ is rectangle, in round or ellipse One kind.

84. MTJ according to claim 20, which is characterized in that the shape of the MTJ is rectangle, in round or ellipse One kind.

85. MTJ according to claim 21, which is characterized in that the shape of the MTJ is rectangle, in round or ellipse One kind.

86. MTJ according to claim 22, which is characterized in that the shape of the MTJ is rectangle, in round or ellipse One kind.

87. MTJ according to claim 23, which is characterized in that the shape of the MTJ is rectangle, in round or ellipse One kind.

88. MTJ according to claim 24, which is characterized in that the shape of the MTJ is rectangle, in round or ellipse One kind.

89. MTJ according to claim 25, which is characterized in that the shape of the MTJ is rectangle, in round or ellipse One kind.

90. MTJ according to claim 26, which is characterized in that the shape of the MTJ is rectangle, in round or ellipse One kind.

91. MTJ according to claim 27, which is characterized in that the shape of the MTJ is rectangle, in round or ellipse One kind.

92. MTJ according to claim 28, which is characterized in that the shape of the MTJ is rectangle, in round or ellipse One kind.

93. MTJ according to claim 29, which is characterized in that the shape of the MTJ is rectangle, in round or ellipse One kind.

94. MTJ according to claim 30, which is characterized in that the shape of the MTJ is rectangle, in round or ellipse One kind.

95. MTJ according to claim 31, which is characterized in that the shape of the MTJ is rectangle, in round or ellipse One kind.

96. MTJ according to claim 32, which is characterized in that the shape of the MTJ is rectangle, in round or ellipse One kind.

97. MTJ according to claim 33, which is characterized in that the shape of the MTJ is rectangle, in round or ellipse One kind.

98. MTJ according to claim 34, which is characterized in that the shape of the MTJ is rectangle, in round or ellipse One kind.

99. MTJ according to claim 35, which is characterized in that the shape of the MTJ is rectangle, in round or ellipse One kind.

100. MTJ according to claim 36, which is characterized in that the shape of the MTJ is rectangle, in round or ellipse One kind.

101. the MTJ according to claim 37, which is characterized in that the shape of the MTJ is rectangle, in round or ellipse One kind.

102. the MTJ according to claim 38, which is characterized in that the shape of the MTJ is rectangle, in round or ellipse One kind.

103. MTJ according to claim 39, which is characterized in that the shape of the MTJ is rectangle, in round or ellipse One kind.

104. MTJ according to claim 40, which is characterized in that the shape of the MTJ is rectangle, in round or ellipse One kind.

105. MTJ according to claim 41, which is characterized in that the shape of the MTJ is rectangle, in round or ellipse One kind.

106. MTJ according to claim 42, which is characterized in that the shape of the MTJ is rectangle, in round or ellipse One kind.

107. MTJ according to claim 43, which is characterized in that the shape of the MTJ is rectangle, in round or ellipse One kind.

108. MTJ according to claim 44, which is characterized in that the shape of the MTJ is rectangle, in round or ellipse One kind.

109. MTJ according to claim 45, which is characterized in that the shape of the MTJ is rectangle, in round or ellipse One kind.

110. MTJ according to claim 46, which is characterized in that the shape of the MTJ is rectangle, in round or ellipse One kind.

111. MTJ according to claim 47, which is characterized in that the shape of the MTJ is rectangle, in round or ellipse One kind.

112. MTJ according to claim 48, which is characterized in that the shape of the MTJ is rectangle, in round or ellipse One kind.

113. MTJ according to claim 49, which is characterized in that the shape of the MTJ is rectangle, in round or ellipse One kind.

114. MTJ according to claim 50, which is characterized in that the shape of the MTJ is rectangle, in round or ellipse One kind.

115. MTJ according to claim 51, which is characterized in that the shape of the MTJ is rectangle, in round or ellipse One kind.

116. MTJ according to claim 52, which is characterized in that the shape of the MTJ is rectangle, in round or ellipse One kind.

117. MTJ according to claim 53, which is characterized in that the shape of the MTJ is rectangle, in round or ellipse One kind.

118. MTJ according to claim 54, which is characterized in that the shape of the MTJ is rectangle, in round or ellipse One kind.

119. MTJ according to claim 55, which is characterized in that the shape of the MTJ is rectangle, in round or ellipse One kind.

120. MTJ according to claim 56, which is characterized in that the shape of the MTJ is rectangle, in round or ellipse One kind.

121. MTJ according to claim 57, which is characterized in that the shape of the MTJ is rectangle, in round or ellipse One kind.

122. MTJ according to claim 58, which is characterized in that the shape of the MTJ is rectangle, in round or ellipse One kind.

123. MTJ according to claim 59, which is characterized in that the shape of the MTJ is rectangle, in round or ellipse One kind.

124. MTJ according to claim 60, which is characterized in that the shape of the MTJ is rectangle, in round or ellipse One kind.

125. MTJ according to claim 61, which is characterized in that the shape of the MTJ is rectangle, in round or ellipse One kind.

126. MTJ according to claim 62, which is characterized in that the shape of the MTJ is rectangle, in round or ellipse One kind.

127. MTJ according to claim 63, which is characterized in that the shape of the MTJ is rectangle, in round or ellipse One kind.

128. MTJ according to claim 64, which is characterized in that the shape of the MTJ is rectangle, in round or ellipse One kind.

129. MTJ according to claim 65, which is characterized in that the shape of the MTJ is rectangle, in round or ellipse One kind.

130. MTJ according to claim 66, which is characterized in that the shape of the MTJ is rectangle, in round or ellipse One kind.

131. MTJ according to claim 67, which is characterized in that the shape of the MTJ is rectangle, in round or ellipse One kind.

132. MTJ according to claim 68, which is characterized in that the shape of the MTJ is rectangle, in round or ellipse One kind.

133. MTJ according to claim 69, which is characterized in that the shape of the MTJ is rectangle, in round or ellipse One kind.

134. a kind of magnetic memory, which is characterized in that including it is multiple as the described in any item MTJ of claim 1~133 and with institute State the corresponding switching tube of MTJ, in which:

The MTJ includes reading end, write-in end and common end, first ferromagnetic layer for reading end and being located at the MTJ On, said write end is located at one end of the heavy metal layer of the MTJ, and the common end is located at the huge sum of money of the MTJ Belonging to the other end of layer, the common end of the MTJ connects bit line BL by switching tube, and the reading end of the MTJ connects read line RL, The write-in end of the MTJ connects source line SL；

When switching tube conducting, if a high voltage in the BL and SL, another adds low-voltage, described in Data are written in MTJ；

When switching tube conducting, if a high voltage in the BL and RL, another adds low-voltage, from described Data are read in MTJ.