CN112701217A - Magnetic structure, spin transfer torque-magnetic random access memory and writing method thereof - Google Patents
Magnetic structure, spin transfer torque-magnetic random access memory and writing method thereof Download PDFInfo
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- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N50/00—Galvanomagnetic devices
- H10N50/10—Magnetoresistive devices
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- G—PHYSICS
- G11—INFORMATION STORAGE
- G11C—STATIC STORES
- G11C11/00—Digital stores characterised by the use of particular electric or magnetic storage elements; Storage elements therefor
- G11C11/02—Digital stores characterised by the use of particular electric or magnetic storage elements; Storage elements therefor using magnetic elements
- G11C11/16—Digital stores characterised by the use of particular electric or magnetic storage elements; Storage elements therefor using magnetic elements using elements in which the storage effect is based on magnetic spin effect
- G11C11/165—Auxiliary circuits
- G11C11/1675—Writing or programming circuits or methods
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- Mram Or Spin Memory Techniques (AREA)
Abstract
The invention discloses a magnetic structure of an artificial anti-ferromagnetic free layer regulated by a ferroelectric auxiliary electric field and a spin transfer torque-magnetic random access memory (STT-MRAM), and relates to circuits and devices of magnetic/ferromagnetic/ferroelectric materials or structures and application fields thereof. The magnetic structure includes: a ferroelectric layer capable of generating stable polarization electric field and charge transfer effect and an electric field controlled magnetic tunnel junction based on artificial antiferromagnetic free layer. The artificial antiferromagnetic free layer can realize the conversion of antiferromagnetic coupling and ferromagnetic coupling under the auxiliary regulation and control of the ferroelectric polarization electric field, reduce the writing current density and save the energy consumption.
Description
Technical Field
The invention relates to the field of spintronics, in particular to a Spin-transfer Torque-Magnetic Random Access Memory (STT-MRAM) for regulating and controlling interlayer coupling of an artificial anti-ferromagnetic free layer by a ferroelectric polarization auxiliary electric field and erasing and writing data by using Spin transfer Torque
Background
The core memory cell of the MRAM is a Magnetic Tunnel Junction (MTJ) or a Spin Valve (Spin Valve). The MTJ consists of a reference layer, a nonmagnetic spacer layer, and a free layer, where the reference layer and the free layer are typically ferromagnetic materials, the nonmagnetic spacer layer is an insulator, also known as a tunneling layer, located between the reference layer and the free layer, and electrons mainly tunnel through the MTJ in a tunneling fashion. The magnetization direction of the reference layer is unchanged and the magnetization direction of the free layer can be changed. Data is written to the MTJ in the form of a magnetization state: the MTJ assumes a low resistance state when the magnetization directions of the free layer and the reference layer are parallel for representing a binary state "1" for data storage, and a high resistance state when the magnetization directions of the free layer and the reference layer are anti-parallel for representing a binary state "0".
The spin transfer torque-magnetic random access memory STT-MRAM utilizes spin transfer torque to overturn the magnetization of a free layer to realize data writing, but the critical writing current and the writing time of the STT-MRAM are changed in inverse proportion, so that the writing current needs to be increased when the writing speed is increased, the arrangement density of a memory cell array is limited by the larger spin polarization current, the power consumption is increased, and meanwhile, the generated Joule heat also has a great damage effect on the stability of the device.
In order to solve the problem, the invention provides a ferroelectric auxiliary electric field controlled magnetic random access memory, which can reduce the writing current density and save the power consumption, and is an important technical problem to be solved by the research in the field.
Disclosure of Invention
In view of the above-mentioned drawbacks of the prior art, the technical problem to be solved by the present invention is to solve the problem that the spin transfer torque-random access memory consumes more power while the generated joule heat has a potentially damaging effect on the stability of the device.
In order to achieve the above object, the present invention provides a magnetic structure, which is characterized in that the magnetic structure comprises an electric field controlled magnetic tunnel junction based on an artificial antiferromagnetic free layer, and a ferroelectric layer capable of generating a polarization electric field;
the magnetic tunnel junction includes: the spacer layer is positioned between the fixed layer and the free layer.
The artificial antiferromagnetic free layer includes: a second magnetic layer formed under the spacer layer, a non-magnetic coupling layer formed under the second magnetic layer, and a first magnetic layer formed under the non-magnetic coupling layer.
The ferroelectric layer is formed under the artificial antiferromagnet of the free layer, and an insulating layer can be added between the ferroelectric layer and the artificial antiferromagnet free layer.
The invention also provides a spin-transfer torque-magnetic random access memory characterized in that,
the spin transfer torque-magnetic random access memory includes the magnetic structure, and further includes:
a first electrode over the fixed layer;
a second electrode between the first magnetic layer and the ferroelectric layer;
a third electrode located below the ferroelectric layer;
the first electrode and the second electrode are used for applying vertical current passing through the magnetic tunnel junction;
the third electrode is used for applying voltage pulse to the ferroelectric layer to enable the ferroelectric layer to generate a polarization electric field.
The ferroelectric layer can generate a stable polarization electric field under the action of an external electric field, and the magnetic tunnel junction based on the artificial antiferromagnetic free layer is adjusted and controlled in an auxiliary manner;
preferably, the ferroelectric layer is formed of an insulating or semiconducting ferroelectric material, the ferroelectric layer being formed of one or more of the following materials: PMN-PT ((1-x) [ PbMg)1/3Nb2/3O3]-x[PbTiO3])、PZN-PT((1-x)Pb(Zn1/3Nb2/3)O3]-x[PbTiO3])、PSN-PT(Pb(Sc1/2Nb1/2)-PbTiO3)、Pb(In1/2Nb1/2)-PbTiO3，Pb(Yb1/2Nb1/2)-PbTiO3、BaTiO3、BiFeO3、PbTiO3、SrTiO3、LiNbO3、LiTaO3、HfO2、ZrO2、Hf(1-x)ZrxO2、SiC、GaN、KNbO3、KH2PO4、Pb(Zr1-xTix)O3、LiOsO3、CaTiO3、KTiO3、BaxSr1-xTiO3(BST)、(Pb，La)TiO3(PLT)、LaTiO3、(BiLa)4Ti3O12(BLT)、SrRuO3、BaHfO3、La1-xSrxMnO3、BaMnF4、α-In2Se3、β′-In2Se3、BaNiF4、BaMgF4、BaCuF4、BaZnF4、BaCoF4、BaFeF4、BaMnF4、CuInP2S6、AgBiP2Se6、CuInP2Se6、MoS2、MoTe2、WS2、WSe2、WTe2、BiN、ZnO、SnTe、SnSe、SnS、GeSe、GeS、GeTe、GaAs、P2O3、SiGe、SiTe、SiSn、GeSn、β-GeSe、PbTe、MoSSe、GaTeCl、MAPbI3、MAPbBr3、Ba2PbCl4、PVDF、P(VDF-TrFE)、C13H14ClN5O2Cd、TiO2、Cu2O、SeO3、Sc2CO2、CrN、CrB2、g-C6N8H and a polar chemical group-CH2F, -CHO, -COOH or-CONH2Modified graphene, germanene, stannene, disulfides.
Preferably, the artificial antiferromagnetic free layer can be converted from antiferromagnetic coupling to ferromagnetic coupling under the action of an electric field; and applying a depolarization electric field, and retreating the free layer from the ferromagnetic coupling to the antiferromagnetic coupling, namely regulating the transition between the antiferromagnetic coupling and the ferromagnetic coupling by the electric field.
The magnetization directions of the first magnetic layer and the second magnetic layer are perpendicularly directed out of the plane or parallel to the plane.
Preferably, the ferroelectric layer generates electric polarization under the action of an external electric field to form a polarization electric field, and the direction of the self-generating field of the polarization electric charges is consistent with that of the external electric field. After ferroelectric polarization, positive (negative) charges accumulate on the upper surface and negative (positive) charges accumulate on the lower surface, and at this time, the electrode layer in contact therewith accumulates negative (positive) charges on the lower surface and positive (negative) charges on the upper surface. Because the difference of the electronegativity of the interface is obvious, the obvious charge transfer occurs between the ferroelectric layer and the electrode layer, and the electric field intensity penetrating through the middle electrode layer is effectively amplified (compared with pure electric field regulation), at the moment, the external electric field required by regulating and controlling the free layer to be converted from antiferromagnetic coupling to ferromagnetic coupling can be effectively reduced by the polarization electric field in cooperation with the charge transfer effect, and the writing current density is reduced.
Preferably, the ferroelectric layer can be returned from the saturated electric polarization state to the depolarized state by applying an oscillation damping voltage or a reverse polarization voltage pulse, thereby completing the process of returning the artificial antiferromagnetic free layer from ferromagnetic coupling to antiferromagnetic coupling.
The present invention also provides a method of operating a spin-transfer torque magnetic random access memory, comprising the steps of:
s100, applying a vertical current flowing through the free layer, the spacer layer and the fixed layer, and applying a voltage to the ferroelectric layer to control the ferroelectric layer to apply a polarization electric field to the free layer, so that a first magnetic layer and a second magnetic layer of the free layer are converted into ferromagnetic coupling, thereby writing data to the memory cell;
s200, applying oscillation attenuation voltage or reverse polarization voltage pulse to the ferroelectric layer to generate a depolarization electric field to enable the ferroelectric layer to return to a depolarization state from a saturation electric polarization state, so that the first magnetic layer and the second magnetic layer of the free magnetic layer become anti-ferromagnetic coupling, and data storage is completed in the storage unit;
wherein the data written to the memory cell is dependent on the direction of the vertical current.
Compared with the prior art, the invention has the advantages that:
(1) the invention uses the artificial anti-ferromagnetic structure as the free layer of the magnetic tunnel junction to form a stack structure of 'fixed layer-spacer layer-artificial anti-ferromagnetic free layer', the free layer based on the artificial anti-ferromagnetic structure realizes the conversion of anti-ferromagnetic coupling to ferromagnetic coupling under the regulation and control of an electric field, and combines the current to directly regulate and control the ferromagnetic layer close to the magnetic tunnel junction interlayer, namely the relative orientation of the magnetic moment between the second magnetic layer and the fixed layer, so as to realize data writing, thereby reducing the overturning current of the free layer;
(2) the magnetic tunnel junction is applied to the magnetic random access memory device, and the ferroelectric layer generates a polarization electric field and an interface charge transfer effect to effectively assist in regulating and controlling the magnetic state coupling transformation of the free layer and reduce the overturning current of the free layer, so that the power consumption of the device is reduced, the heating of the device is reduced, the volume of the device is reduced and the array density of the memory cell is improved;
(3) the invention uses an artificially synthesized antiferromagnetic structure as the free layer of the magnetic tunnel junction, has strong anti-interference capability, further develops the application space of the spin electronic device and promotes the development of the novel memory industry.
The conception, the specific structure and the technical effects of the present invention will be further described with reference to the accompanying drawings to fully understand the objects, the features and the effects of the present invention.
Drawings
The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principles of the invention:
fig. 1(a) shows a schematic diagram of a ferroelectric layer accumulating positive charges on its upper surface and negative charges on its lower surface after saturation polarization by an applied electric field;
FIG. 1(b) shows a schematic diagram of applying a reverse polarization pulse electric field to the ferroelectric layer after writing data to make the ferroelectric layer depolarize ferroelectric polarization;
FIG. 1(c) shows another schematic diagram of applying an oscillation-damping pulse electric field Es to make the ferroelectric layer depolarize ferroelectric after writing data;
FIG. 1(d) shows a schematic diagram of applying an oscillation-damping pulse electric field Es to a ferroelectric layer during data writing and storing in a spin-transfer torque magnetic random access memory;
FIG. 1(e) shows a schematic diagram of the application of a reverse polarization pulse to a ferroelectric layer during data writing and storing in a spin-transfer torque magnetic random access memory;
FIG. 2(a) shows a schematic diagram of a ferroelectric assisted electric field modulated artificial antiferromagnetic free layer spin transfer torque magnetic random access memory device;
FIG. 2(b) shows a schematic diagram of a magnetic tunnel junction device based on FIG. 2(a) for controlling the magnitude of the electric field in the artificial antiferromagnetic free layer by adding an insulating layer;
FIG. 3(a) shows a schematic diagram of a spin-transfer torque-magnetic random access memory write data "0";
FIG. 3(b) is a schematic diagram showing a process of applying a reverse electric field to store data "0";
FIG. 3(c) shows a schematic diagram of a process of applying an electric field of an oscillation-damped pulse to save data "0";
FIG. 4 shows a schematic diagram of the spin-transfer torque-magnetic random access memory for performing a data "0" read;
FIG. 5(a) shows a schematic diagram of a spin-transfer torque-magnetic random access memory write data "1";
FIG. 5(b) is a schematic diagram showing a spin transfer torque-magnetic random access memory storing data "1" by applying a reverse electric field;
FIG. 5(c) is a schematic diagram showing a process of applying an electric field of an oscillation-damping pulse to save data "1";
FIG. 6 is a schematic diagram showing the process of the spin transfer torque-magnetic random access memory for completing the reading of data "1";
FIG. 7 illustrates a schematic diagram of a spin-transfer torque magnetic random access memory based on a structure for writing, storing and reading data, although not shown, the spin-transfer torque magnetic random access memory may include a plurality of memory cells shown in FIG. 7 arranged in an array, each memory cell may store data "0" or "1", and a practical application may depend on such an array structure for writing, storing and reading a large amount of binary information;
wherein 11-the first magnetic layer, 12-the non-magnetic coupling layer, 13-the second magnetic layer, 20-the magnetic tunnel junction, 21-the free layer, 22-the spacer layer, 23-the pinned layer, 25-the ferroelectric layer, 26-the insulating layer, 31-the first electrode, 32-the second electrode, 33-the third electrode.
Detailed Description
The technical contents of the preferred embodiments of the present invention will be more clearly and easily understood by referring to fig. 1(a) to 7 of the specification. The present invention may be embodied in many different forms of embodiments and the scope of the invention is not limited to the embodiments set forth herein.
In the drawings, structurally identical elements are represented by like reference numerals, and structurally or functionally similar elements are represented by like reference numerals throughout the several views. The size and thickness of each component shown in the drawings are arbitrarily illustrated, and the present invention is not limited to the size and thickness of each component. The thickness of the components may be exaggerated where appropriate in the figures to improve clarity.
Fig. 1(a) shows a schematic diagram of the ferroelectric layer 25 accumulating positive charges on the upper surface and negative charges on the lower surface after saturation polarization under the action of an applied electric field Ew; fig. 1(b) shows a schematic diagram of applying a reverse polarization pulse electric field Es to the ferroelectric layer 25 after writing data, so as to make the ferroelectric layer depolarize ferroelectric polarization; fig. 1(c) shows another schematic diagram of applying an oscillation-damping pulse electric field Es to the ferroelectric layer 25 after writing data to make the ferroelectric layer depolarize ferroelectric polarization; fig. 1(d) shows that an electric field pulse Ew is first applied to the ferroelectric layer 25, and a ferroelectric polarization field is applied to the free layer 21 to write data; after writing, applying oscillation attenuation electric field pulse Es to the ferroelectric layer 25 to remove ferroelectric polarization, namely finishing data storage; fig. 1(e) shows that an electric field pulse Ew is first applied to the ferroelectric layer 25, and a ferroelectric polarization field is applied to the free layer 21 to write data; after writing, the ferroelectric layer 25 is applied with a reverse polarization electric field pulse Es to perform unsaturated ferroelectric polarization, i.e., data storage is completed. In the figure, an external electric field Ew and a reverse electric field pulse Es are generated by other devices; ew is a uniform electric field pulse, and Es is an oscillation attenuation pulse or a reverse polarization pulse electric field.
The ferroelectric layer 25 may be formed of an insulating or semiconductor ferroelectric material in the present embodiment, and examples of materials that may be used for the ferroelectric layer 25 include, but are not limited to:
PMN-PT((1-x)[PbMg1/3Nb2/3O3]-x[PbTiO3])、PZN-PT((1-x)Pb(Zn1/3Nb2/3)O3]-x[PbTiO3])、PSN-PT(Pb(Sc1/2Nb1/2)-PbTiO3)、Pb(In1/2Nb1/2)-PbTiO3，Pb(Yb1/2Nb1/2)-PbTiO3、BaTiO3、BiFeO3、PbTiO3、SrTiO3、LiNbO3、LiTaO3、HfO2、ZrO2、Hf(1-x)ZrxO2、SiC、GaN、KNbO3、KH2PO4、Pb(Zr1-xTix)O3、LiOsO3、CaTiO3、KTiO3、BaxSr1-xTiO3(BST)、(Pb，La)TiO3(PLT)、LaTiO3、(BiLa)4Ti3O12(BLT)、SrRuO3、BaHfO3、La1-xSrxMnO3、BaMnF4、α-In2Se3、β′-In2Se3、BaNiF4、BaMgF4、BaCuF4、BaZnF4、BaCoF4、BaFeF4、BaMnF4、CuInP2S6、AgBiP2Se6、CuInP2Se6、MoS2、MoTe2、WS2、WSe2、WTe2、BiN、ZnO、SnTe、SnSe、SnS、GeSe、GeS、GeTe、GaAs、P2O3、SiGe、SiTe、SiSn、GeSn、β-GeSe、PbTe、MoSSe、GaTeCl、MAPbI3、MAPbBr3、Ba2PbCl4、PVDF、P(VDF-TrFE)、C13H14ClN5O2Cd、TiO2、Cu2O、SeO3、Sc2CO2、CrN、CrB2、g-C6N8h and a polar chemical group-CH2F, -CHO, -COOH or-CONH2Modified graphene, germanene, stannene, disulfides. Wherein the ferroelectric layer has a thickness in the range of 0.1nm to 500nm, preferably in the range of 1nm to 200nm, more preferably in the range of 10nm to 100 nm.
FIG. 2(a) shows a ferroelectric assisted electric field modulated artificial antiferromagnetic free layer spinA schematic diagram of a transferred moment magnetic random access memory device, which is composed of a magnetic tunnel junction 20, a first electrode 31, a second electrode 32, a third electrode 33, and a ferroelectric layer 25, wherein the magnetic tunnel junction 20 includes a pinned layer 23, a free layer 21, and a spacer layer 22 between the pinned layer 23 and the free layer 21; the magnetization directions of the pinned layer 23 and the free layer 21 are directed perpendicularly out of plane or parallel in plane, and the free layer 21 regulates the transition of its antiferromagnetic coupling and ferromagnetic coupling by an electric field. FIG. 2(b) based on FIG. 2(a), the electric field in the free layer 21 is controlled by adding an insulating layer 26, the thickness of the insulating layer 26 is 0 nm-100nm, the material of the insulating layer is selected from but not limited to Al2O3、MgO、SiO2And the like oxides, nitrides or oxynitrides. In some embodiments, the multilayer structure shown in fig. 2(a) and 2(b) may have various shapes, such as circular, oval, square, rectangular, circular, and the like.
In the present embodiment, the free layer 21 can be controlled by an electric field, the magnetization direction of the free layer 21 points out of plane or parallel to in-plane, the free layer 21 is composed of "first magnetic layer 11-nonmagnetic coupling layer 12-second magnetic layer 13", wherein the materials of the first and second magnetic layers 11 and 13 can be formed by common ferromagnetic materials, including but not limited to: fe. Co, Ni, CoFe, CoFeB, CoCrPt structural material, or (Co/Ni) m, (Co/Pd) n, (Co/Pt) q multilayer repeated stacked magnetic structural material, wherein m, n and q refer to the repeated times of multilayer stacking;
or may be formed of ferromagnetic materials with strong perpendicular magnetocrystalline anisotropy, including but not limited to Fe, Fe-4% Si, Co, CoFe2O4、BaFe12O19Etc.; the magnetization directions of the first and second magnetic layers 11 and 13 are perpendicularly directed out of plane or parallel to in-plane, and the thickness may be in the range of 0.1nm to 8nm, preferably in the range of 0.2nm to 5nm, and more preferably in the range of 0.2nm to 3 nm; in some embodiments, second magnetic layer 13 near pinned layer 23 has a greater magnetic moment than first magnetic layer 11 away from pinned layer 23. For example, second magnetic layer 13 may have a greater thickness than first magnetic layer 11, or second magnetic layer 13 may be formed of a material having a greater magnetic moment than first magnetic layer 11。
The nonmagnetic coupling layer 12 may be formed of a nonmagnetic conductive material including, but not limited to, an alloy consisting of one or more elements of Cu, Rh, Pd, Ag, Ir, Pt, Au, Nb, Ta, Cr, Mo, W, Re, Ru, Os, and the thickness of the nonmagnetic coupling layer 12 may be in the range of 0.1nm to 10nm, and more preferably in the range of 0.2nm to 5 nm.
Before an electric field is applied, the free layer 21 is in an antiferromagnetic state, the diameter of the free layer is 1 nm-100nm, the free layer is placed in an electric field assisted by the ferroelectric layer, the voltage regulation and control required range of the electric field is 0.1V-15V, the antiferromagnetic coupling of the free layer 21 is converted into ferromagnetic coupling, the electric field applied to the free layer 21 is cancelled, the free layer 21 is retreated from the ferromagnetic coupling into the antiferromagnetic coupling, and the conversion of the antiferromagnetic coupling and the ferromagnetic coupling can be regulated and controlled through the electric field.
The pinned layer 23 may be formed of a ferromagnetic or ferrimagnetic metal material and alloys thereof, including but not limited to Fe, Co, Ni, Mn, NiFe, FePd, FePt, CoFe, CoPt, YCo, LaCo, PrCo, NdCo, SmCo, CoFeB, BiMn, or NiMnSb, or a multi-element alloy material made of the ferromagnetic or ferrimagnetic metal in combination with one or more of Hf, Pd, Pt, B, Al, Zr, Ta, Cr, Mo, Nb; or synthetic ferromagnetic or ferrimagnetic materials including, but not limited to, 3d/4d/4f/5d/5 f/rare earth metal layer stacks of artificial multilayer materials such as Co/Ir, Co/Pt, Co/Pd, CoCr/Pt, Co/Au, Ni/Co, etc.; or from a semi-metallic ferromagnetic material, e.g. of the form XYZ or X2Heusler alloys of YZ, wherein X is selected from one or more of Mn, Fe, Co, Ni, Pd or Cu, Y is selected from one or more of Ti, V, Cr, Mn, Fe, Co or Ni, and Z is selected from one or more of Al, Ga, In, Si, Ge, Sn or Sb; or an artificial antiferromagnetic structure, wherein the magnetic layer material is selected from Fe, Co, CoFe, Ni, CoCrPt, CoFeB, (Co/Ni) m, (Co/Pd) n or (Co/Pt) q, m, n, q refer to the number of times of repetition of the multilayer stack, and the coupling layer material is selected from an alloy consisting of one or more elements of Nb, Ta, Cr, Mo, W, Re, Ru, Os, Rh, Ir, Pt, Cu, Ag or Au; in some embodiments, the thickness of the fixed layer 23 may be in the range of 2nm to 40nm, preferably in the range of 2nm to 20nm, morePreferably in the range of 2nm to 10 nm.
The spacer layer 22 is located between the fixed layer 23 and the free layer 21 and may comprise a non-magnetic, electrically conductive material or a non-magnetic, insulating material. When the spacer layer 22 is formed of a non-magnetically conductive material, its thickness is preferably no greater than the spin-electron mean free path of the material. When the spacer layer 22 is formed of a non-magnetic insulating material, it is also commonly referred to as a barrier layer through which electrons can flow between the fixed layer 23 and the free layer 21 by tunneling.
The material of the spacer layer 22 is selected from, but not limited to, oxides, nitrides or oxynitrides, and the constituent elements of the oxides, nitrides or oxynitrides are selected from one or more of Mg, B, Al, Ca, Sr, La, Ti, Hf, V, Ta, Cr, W, Ru, Cu, In, Si or Eu doped to form compounds; or the material of the spacer layer 22 is selected from a non-magnetic metal or alloy, and the constituent elements of the metal or alloy are selected from, but not limited to, one or more of Cu, Ag, Au, Al, Pt, Ta, Ti, Nb, Os, Ru, Rh, Y, Mg, Pd, Cr, W, Mo, or V; or the material of the spacer layer 22 is selected from, but not limited to, SiC, C, or other ceramic materials; in some embodiments, the thickness of the spacer layer 22 may be in the range of 0.1nm to 10nm, preferably in the range of 0.1nm to 5nm, more preferably in the range of 0.1nm to 2 nm.
In other embodiments, the spacer layer 22 may have other configurations, such as a granular layer that incorporates conductive pathways in the insulator system.
In this embodiment, both the pinned layer 23 and the free layer 21 are conductive.
A first electrode 31 is located above the fixed layer 23; a second electrode 32 is located between the first magnetic layer 11 and the ferroelectric layer 25; a third electrode 33 is located below the ferroelectric layer 25; the first electrode 31 and the second electrode 32 are used to apply a perpendicular current through the magnetic tunnel junction. The third electrode 33 is used for applying a voltage pulse to the ferroelectric layer, so that the ferroelectric layer generates a polarization electric field and a charge transfer effect.
In some embodiments, the thickness of the second electrode 32 is less than the thickness of the first electrode 31 and the third electrode 33.
In some embodiments, the first electrode 31, the second electrode 32, and the third electrode 33 may be formed of a metal or an alloy material having good conductivity, including but not limited to Li, Mg, Al, Ca, Sc, Ti, V, Mn, Cu, Zn, Ga, Ge, Sr, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, In, Sn, Sb, Ba, Hf, Ta, W, Re, Os, Ir, Pt, Au, Tl, Pb, Bi, Po, La, Ce, Pr, Nd, Pm, Sm, Gd, Tb, Dy, Ho, Er, Tm, or Yb, and the like, and may also be formed of a carbon-based conductive material, including but not limited to graphite, carbon nanotube, or bamboo charcoal, and the like. The thickness of the first electrode 31 and the third electrode 33 may be in the range of 1nm-1 μm, preferably in the range of 5nm-500nm, more preferably in the range of 10nm-200 nm. The thickness of the second electrode 32 may be smaller than the thickness of the other electrodes, for example, may be in the range of 0.1nm-200nm, preferably in the range of 0.5nm-100nm, and more preferably in the range of 1nm-20nm, so as to facilitate the ferroelectric layer 25 to apply a vertical electric field to the free layer 21.
Fig. 3(a) shows a schematic process diagram of a spin-transfer torque-magnetic random access memory writing data "0", and the process of the spin-transfer torque-magnetic random access memory writing data "0" based on an artificial anti-ferromagnetic free layer under the combined action of ferroelectric auxiliary electric field regulation and spin-transfer torque is as follows: a forward high voltage Vwp is applied to the first electrode 31, the second electrode 32 is grounded, a vertically downward spin current is generated in the magnetic tunnel junction 20, and simultaneously, a forward voltage Vw is applied to the third electrode 33, the ferroelectric layer 25 is polarized in saturation, a polarization electric field is formed, positive charges are accumulated on the upper surface of the ferroelectric layer 25, negative charges are accumulated on the lower surface, and at this time, negative charges are accumulated on the lower surface of the second electrode 32, and positive charges are accumulated on the upper surface. Because the difference of the electronegativity of the interface is obvious, the obvious charge transfer occurs between the ferroelectric layer 25 and the second electrode 32, the electric field intensity penetrating through the spin-orbit torque material layer is amplified, and the ferromagnetic coupling state of the free layer 21 is jointly regulated and controlled by cooperating with the charge transfer effect. . The spin current inverts the magnetic moment of the second magnetic layer 13 to the opposite direction of the magnetic moment of the pinned layer 23 by the spin transfer torque, and at the same time, the free layer 21 is converted from antiferromagnetic coupling to ferromagnetic coupling by the polarization electric field generated from the ferroelectric layer 25 and the charge transfer effect, so that the magnetization direction of the first magnetic layer 11 is parallel to that of the second magnetic layer 13, and writing of data "0" is started. Fig. 3(b) shows a schematic diagram of a process of applying an inverse electric field to store data "0", after removing the voltage of the first electrode 31 or grounding it, and removing the electric field Ew applied to the ferroelectric layer, applying an inverse electric field Es as shown in fig. 1(b), so that ferroelectric unsaturated polarization occurs, the polarization electric field in the vertical direction is reduced, so that the free layer 21 changes from ferromagnetic coupling to antiferromagnetic coupling, the magnetic moment of the second magnetic layer 13 is greater than that of the first magnetic layer 11, so that the magnetic moment of the first magnetic layer 11 is reversed to be antiparallel to the magnetic moment of the second magnetic layer 13, and at this time, the magnetization directions of the pinned layer 23 and the second magnetic layer 13 are antiparallel (high resistance state), thereby completing the storage of data "0". Fig. 3(c) shows a schematic diagram of a process of storing data "0" by applying an oscillation-damping pulse electric field, after removing the voltage of the first electrode 31 or grounding it, and removing the electric field Ew applied to the ferroelectric layer 25, applying the oscillation-damping pulse electric field Es shown in fig. 1(c), so as to generate antiferroelectric polarization, and reduce the polarization electric field in the vertical direction, so that the free layer 21 is changed from ferromagnetic coupling to antiferromagnetic coupling, and the magnetic moment of the second magnetic layer 13 is greater than that of the first magnetic layer 11, so that the magnetic moment of the first magnetic layer 11 is flipped to be antiparallel to the magnetic moment of the second magnetic layer 13, and at this time, the magnetization directions of the pinned layer 23 and the second magnetic layer 13 are antiparallel (high resistance state), thereby completing the storage of data "0".
Fig. 4 shows a process of reading data "0" of the spin transfer torque-magnetic random access memory, in which a small forward voltage Vrp is applied to the first electrode 31, and the second electrode 32 is Grounded (GND), so that the resistance state of the magnetic tunnel junction 20 can be read as a high resistance state by a vertical current formed in the magnetic tunnel junction 20, thereby reading data "0".
Fig. 5(a) to 5(c) show schematic diagrams of a process of writing and storing data "1" in the spin-transfer torque-magnetic random access memory. Fig. 5(a) shows a schematic process of writing data "1" in the spin transfer torque-magnetic random access memory based on the artificial anti-ferromagnetic free layer under the combined action of the ferroelectric auxiliary electric field regulation and the spin transfer torque: a negative high voltage Vwn is applied to the first electrode 31, the second electrode 32 is grounded, a vertically upward spin current is generated in the magnetic tunnel junction 20, and simultaneously, a positive voltage Vw is applied to the third electrode 33, the ferroelectric layer 25 is polarized in saturation, a polarization electric field is formed, positive charges are accumulated on the upper surface of the ferroelectric layer 25, negative charges are accumulated on the lower surface, and at this time, the second electrode 32 accumulates negative charges on the lower surface and positive charges on the upper surface. Because the difference of the electronegativity of the interface is obvious, the obvious charge transfer occurs between the ferroelectric layer 25 and the second electrode 32, the electric field intensity penetrating through the spin-orbit torque material layer is amplified, and the ferromagnetic coupling state of the free layer 21 is jointly regulated and controlled by cooperating with the charge transfer effect. The spin current inverts the magnetic moment of the second magnetic layer 13 to the same direction as the magnetic moment of the pinned layer 23 by the spin transfer torque, and at the same time, the free layer 21 is converted from antiferromagnetic coupling to ferromagnetic coupling by the polarization electric field generated from the ferroelectric layer 25 and the charge transfer effect, so that the magnetization direction of the first magnetic layer 11 is parallel to that of the second magnetic layer 13, and writing of data "1" is started. Fig. 5(b) shows a schematic diagram of a process of applying an inverse electric field to store data "1", after removing the voltage of the first electrode 31 or grounding it, and removing the electric field Ew applied to the ferroelectric layer, applying an inverse electric field Es as shown in fig. 1(b), so that ferroelectric unsaturated polarization occurs, the polarization electric field in the vertical direction is reduced, so that the artificial antiferromagnetic free layer 21 is changed from ferromagnetic coupling to antiferromagnetic coupling, the magnetic moment of the second magnetic layer 13 is greater than that of the first magnetic layer 11, so that the magnetic moment of the first magnetic layer 11 is flipped to be antiparallel to the magnetic moment of the second magnetic layer 13, and at this time, the magnetization directions of the pinned layer 23 and the second magnetic layer 13 are parallel to each other (low resistance state), thereby completing storage of data "1". Fig. 5(c) shows a schematic process of applying the oscillation damping pulse electric field to store data "1", after removing the voltage of the first electrode 31 or grounding it, and removing the electric field Ew applied to the ferroelectric layer, applying the oscillation damping pulse electric field Es as shown in fig. 1(c), so as to generate antiferroelectric polarization, and the polarization electric field in the vertical direction is reduced, so that the free layer 21 is changed from ferromagnetic coupling to antiferromagnetic coupling, and the magnetic moment of the second magnetic layer 13 is greater than that of the first magnetic layer 11, so that the magnetic moment of the first magnetic layer 11 is flipped to be antiparallel to the magnetic moment of the second magnetic layer 13, and at this time, the magnetization directions of the pinned layer 23 and the second magnetic layer 13 are parallel to each other (low resistance state), thereby completing the storage of data "1".
Fig. 6 shows a schematic diagram of a process of reading data "1", in which a small forward voltage Vrp is applied to the first electrode 31, and the second electrode 32 is Grounded (GND), so that the resistance state of the magnetic tunnel junction 20 can be read to be a low resistance state by a vertical current formed in the magnetic tunnel junction 20, thereby reading data "1".
It should be noted that the current direction described here is a positive current direction, i.e. the electron flow direction is actually opposite to the current direction. Although the positive voltage and the negative voltage are described above, it is to be understood that the voltages are relative concepts, and the signs and the magnitudes of the voltages described above may be appropriately changed as long as the required current can be generated. The principles of the present invention may also be applied to embodiments in which the respective magnetic layers have in-plane magnetizations, the STT current may likewise be used to switch the in-plane magnetization direction of the free magnetic layer, and the perpendicular electric field of the ferroelectric layer 25 may likewise cause the artificial antiferromagnetic structure having the in-plane magnetized free layer 21 to switch from the antiferromagnetic coupling state to the ferromagnetic coupling state.
In the above-described process, attention should be paid to the timing problem of applying the ferroelectric polarization electric field and the write current, ensuring that they are applied with an overlap time T0, which may range from 0.05ns to 10ns, and preferably the ferroelectric polarization electric field should be applied no earlier than the application of the current to ensure that the artificial antiferromagnetic structure of the free layer 21 is in the antiferromagnetic coupling state before data writing, further reducing the critical current density at the time of data writing.
Fig. 7 shows a schematic diagram of a structure of a spin-transfer torque magnetic random access memory based on which data is written, stored, and read, and although not shown, the spin-transfer torque magnetic random access memory may include a plurality of memory cells shown in fig. 7 arranged in an array, each memory cell may store data "0" or "1", and a practical application may depend on such an array structure to write, store, and read a large amount of binary information.
As shown in FIG. 7, SL is the source line, WBL is the write bit line, RBL is the read bit line, WWL is the write word line, RWL is the read word line, VCD is the voltage controller, and VCL is the voltage control line. As shown in FIG. 7, the WBL and RBL may share the same wiring, and the WWL and RWL may share the same wiring. The second electrode 32 of the illustrated cell structure is connected to a source line SL, and may be always Grounded (GND). When data is written in and read from the word line WWL/RWL connected to the gate of the control transistor T1, a high level (Vg) is applied to turn on the circuit, and a current is formed in the magnetic tunnel junction 20; when data is stored, no voltage is applied, the circuit is not turned on, and no current flows through the magnetic tunnel junction 20. The third electrode 33 is externally connected to a voltage controller VCD and then connected to a voltage control line VCL, thereby controlling the polarization electric field and the charge transfer effect of the ferroelectric layer 25. Table 1 shows voltages applied to the respective electrodes when "0" and "1" are read and written in the spin transfer torque-magnetic random access memory in the example.
TABLE 1 spin transfer Torque-MRAM applied voltages to respective electrodes for write-read of "0" and "1" in the MRAM
| Operation of | Write "1" | Store "1" | Write "0" | Store "0" | Reading |
| WWL | Vg | 0 | Vg | 0 | 0 |
| WBL | Vwn | 0 | Vwp | 0 | 0 |
| RWL | 0 | 0 | 0 | 0 | Vg |
| RBL | 0 | 0 | 0 | 0 | Vrp |
| VCL | Vw | Vs | Vw | Vs | 0 |
| SL | GND | GND | GND | GND | GND |
The present invention is not limited to the above-mentioned embodiments, and based on the technical solutions disclosed in the present invention, those skilled in the art can make some substitutions and modifications to some technical features without creative efforts according to the disclosed technical contents, and these substitutions and modifications are all within the protection scope of the present invention.
Claims (8)
1. A magnetic structure is characterized in that the magnetic structure comprises an electric field regulated magnetic tunnel junction based on an artificial antiferromagnetic free layer and a ferroelectric layer capable of generating a polarization electric field;
the magnetic tunnel junction includes: the spacer layer is positioned between the fixed layer and the free layer.
2. The magnetic structure as claimed in claim 1, wherein, preferably,
the free layer includes:
a second magnetic layer formed under the spacer layer, a non-magnetic coupling layer formed under the second magnetic layer, a first magnetic layer formed under the non-magnetic coupling layer;
the ferroelectric layer is formed under the free layer, and an insulating layer may be added between the ferroelectric layer and the free layer.
3. A spin transfer torque-magnetic random access memory characterized in that,
the spin-transfer torque-magnetic random access memory includes the magnetic structure of claim 1, further comprising:
a first electrode over the fixed layer;
a second electrode between the first magnetic layer and the ferroelectric layer;
a third electrode located below the ferroelectric layer;
the first electrode and the second electrode are used for applying vertical current passing through the magnetic tunnel junction;
the third electrode is used for applying voltage to the ferroelectric layer to enable the ferroelectric layer to generate a polarization electric field and a charge transfer effect.
4. The spin-transfer torque-magnetic random access memory of claim 3,
the thickness of the second electrode is less than the thickness of the first electrode and the third electrode.
5. A spin-transfer torque-magnetic random access memory according to claim 3, wherein:
the ferroelectric layer can generate a stable polarization electric field under the action of an external electric field, and the magnetic tunnel junction based on the artificial antiferromagnetic free layer is adjusted and controlled in an auxiliary manner;
the ferroelectric layer is formed of an insulating or semiconducting ferroelectric material, the ferroelectric layer being formed of one or more of the following materials: PMN-PT ((1-x) [ PbMg)1/3Nb2/3O3]-x[PbTiO3])、PZN-PT((1-x)Pb(Zn1/3Nb2/3)O3]-x[PbTiO3])、PSN-PT(Pb(Sc1/2Nb1/2)-PbTiO3)、Pb(In1/2Nb1/2)-PbTiO3，Pb(Yb1/2Nb1/2)-PbTiO3、BaTiO3、BiFeO3、PbTiO3、SrTiO3、LiNbO3、LiTaO3、HfO2、ZrO2、Hf(1-x)ZrxO2、SiC、GaN、KNbO3、KH2PO4、Pb(Zr1-xTix)O3、LiOsO3、CaTiO3、KTiO3、BaxSr1-xTiO3(BST)、(Pb，La)TiO3(PLT)、LaTiO3、(BiLa)4Ti3O12(BLT)、SrRuO3、BaHfO3、La1-xSrxMnO3、BaMnF4、α-In2Se3、β′-In2Se3、BaNiF4、BaMgF4、BaCuF4、BaZnF4、BaCoF4、BaFeF4、BaMnF4、CuInP2S6、AgBiP2Se6、CuInP2Se6、MoS2、MoTe2、WS2、WSe2、WTe2、BiN、ZnO、SnTe、SnSe、SnS、GeSe、GeS、GeTe、GaAs、P2O3、SiGe、SiTe、SiSn、GeSn、β-GeSe、PbTe、MoSSe、GaTeCl、MAPbI3、MAPbBr3、Ba2PbCl4、PVDF、P(VDF-TrFE)、C13H14ClN5O2Cd、TiO2、Cu2O、SeO3、Sc2CO2、CrN、CrB2、g-C6N8H and a polar chemical group-CH2F, -CHO, -COOH or-CONH2Modified graphene, germanene, stannene, disulfides.
6. The spin-transfer torque-magnetic random access memory of claim 3,
the free layer can be converted into ferromagnetic coupling from antiferromagnetic coupling under the action of an electric field; applying a depolarization electric field, and enabling the free layer to retreat from the ferromagnetic coupling to the antiferromagnetic coupling, so that the transition of the antiferromagnetic coupling and the ferromagnetic coupling is regulated through the electric field;
the magnetization directions of the first magnetic layer and the second magnetic layer are perpendicularly directed out of the plane or parallel to the plane;
the first magnetic layer and the second magnetic layer are made of ferromagnetic materials and comprise any one of the following components: fe. Co, Ni, CoFe, CoFeB, CoCrPt structural material, or (Co/Ni) m, (Co/Pd) n, (Co/Pt) q multilayer repeated stacked magnetic structural material, wherein m, n and q refer to the repeated times of multilayer stacking;
or may be formed of a ferromagnetic material having a strong perpendicular magnetocrystalline anisotropy, including any of: fe. Fe-4% Si, Co, CoFe2O4、BaFe12O19(ii) a The magnetization directions of the first magnetic layer and the second magnetic layer are perpendicularly directed out of the plane or parallel to the plane;
the nonmagnetic coupling layer may be formed of a nonmagnetic electrically conductive material including an alloy of one or more elements of Cu, Rh, Pd, Ag, Ir, Pt, Au, Nb, Ta, Cr, Mo, W, Re, Ru, Os.
7. A spin-transfer torque-magnetic random access memory according to claim 3, wherein:
the ferroelectric layer generates electric polarization and charge transfer effect under the action of an external electric field, the direction of a self-generating field of polarized charges is consistent with that of the external electric field, and after the ferroelectric layer close to the free layer generates electric polarization, the polarization electric field acts on the free layer, so that the external electric field required for regulating and controlling the transition of the free layer from antiferromagnetic coupling to ferromagnetic coupling can be reduced;
the ferroelectric layer can be brought back to the depolarized state from the saturated electric polarization state by applying an oscillation damping voltage or a reverse polarization voltage pulse, at which point the return of the free layer from ferromagnetic coupling to antiferromagnetic coupling is accomplished.
8. A method of operating a spin-transfer torque magnetic random access memory according to any of claims 3 to 7, comprising the steps of:
s100, applying a vertical current flowing through the free layer, the spacer layer and the fixed layer, and applying a voltage to the ferroelectric layer to control the ferroelectric layer to generate a polarization electric field and a charge transfer effect, so that the first magnetic layer and the second magnetic layer of the free layer are converted into ferromagnetic coupling, thereby writing data to the memory cell;
s200, applying oscillation attenuation voltage or reverse polarization voltage pulse to the ferroelectric layer to generate a depolarization electric field to enable the ferroelectric layer to return to a depolarization state from a saturation electric polarization state, so that the first magnetic layer and the second magnetic layer of the free magnetic layer become anti-ferromagnetic coupling, and data storage is completed in the storage unit;
wherein the data written to the memory cell is dependent on the direction of the vertical current.
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| CN114067875A (en) * | 2021-11-18 | 2022-02-18 | 致真存储(北京)科技有限公司 | Magnetic memory and data erasing method thereof |
| CN116017986A (en) * | 2023-01-17 | 2023-04-25 | 之江实验室 | Logic gate circuit |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20150119509A (en) * | 2014-04-14 | 2015-10-26 | 한양대학교 산학협력단 | Spin transfer torque-magnetic random access memory(stt-mram) element having multi-level resistance |
| CN107946454A (en) * | 2017-11-17 | 2018-04-20 | 南方科技大学 | A kind of magnetic random memory and its wiring method, read method and preparation method |
| CN109037434A (en) * | 2018-07-06 | 2018-12-18 | 西安交通大学 | Tunnel junction element and magnetic random storage device based on artificial antiferromagnetic free layer |
| CN109036485A (en) * | 2017-06-09 | 2018-12-18 | 桑迪士克科技有限责任公司 | The memory cell of erect spin track torque magnetic random access memory |
| CN109244233A (en) * | 2018-07-26 | 2019-01-18 | 西安交通大学 | Magnetic funnel node device and random storage device based on artificial antiferromagnetic fixing layer |
| CN109560193A (en) * | 2018-10-29 | 2019-04-02 | 西安交通大学 | Magnetic texure and SOT-MRAM based on artificial antiferromagnetic fixing layer |
| US20190386202A1 (en) * | 2018-06-19 | 2019-12-19 | Intel Corporation | Spin orbit memory with multiferroic material |
-
2020
- 2020-12-28 CN CN202011586913.8A patent/CN112701217B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20150119509A (en) * | 2014-04-14 | 2015-10-26 | 한양대학교 산학협력단 | Spin transfer torque-magnetic random access memory(stt-mram) element having multi-level resistance |
| CN109036485A (en) * | 2017-06-09 | 2018-12-18 | 桑迪士克科技有限责任公司 | The memory cell of erect spin track torque magnetic random access memory |
| CN107946454A (en) * | 2017-11-17 | 2018-04-20 | 南方科技大学 | A kind of magnetic random memory and its wiring method, read method and preparation method |
| US20190386202A1 (en) * | 2018-06-19 | 2019-12-19 | Intel Corporation | Spin orbit memory with multiferroic material |
| CN109037434A (en) * | 2018-07-06 | 2018-12-18 | 西安交通大学 | Tunnel junction element and magnetic random storage device based on artificial antiferromagnetic free layer |
| CN109244233A (en) * | 2018-07-26 | 2019-01-18 | 西安交通大学 | Magnetic funnel node device and random storage device based on artificial antiferromagnetic fixing layer |
| CN109560193A (en) * | 2018-10-29 | 2019-04-02 | 西安交通大学 | Magnetic texure and SOT-MRAM based on artificial antiferromagnetic fixing layer |
Non-Patent Citations (1)
| Title |
|---|
| AITIAN CHEN等: ""Giant nonvolatile manipulation of magnetoresistance in magnetic tunnel junctions by electric fields via magnetoelectric coupling"", 《NATURE COMMUNICATIONS》, vol. 10, no. 243, pages 2 * |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113328034A (en) * | 2021-04-28 | 2021-08-31 | 中国科学院微电子研究所 | Storage unit and data writing and reading method thereof, memory and electronic equipment |
| CN114067875A (en) * | 2021-11-18 | 2022-02-18 | 致真存储(北京)科技有限公司 | Magnetic memory and data erasing method thereof |
| CN116017986A (en) * | 2023-01-17 | 2023-04-25 | 之江实验室 | Logic gate circuit |
| CN116017986B (en) * | 2023-01-17 | 2023-08-15 | 之江实验室 | Logic gate circuit |
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