CN112968125B - Device for driving magnetic flip magnetic moment by spin orbit torque without external field and preparation method - Google Patents
Device for driving magnetic flip magnetic moment by spin orbit torque without external field and preparation method Download PDFInfo
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Abstract
The invention discloses a device for driving magnetic flip magnetic moment by external field-free spin orbit moment and a preparation method thereof, wherein the device sequentially comprises the following components from bottom to top: a substrate; functional layer comprising CoFe2O4Layer of CoFe2O4The layer provides an in-plane magnetic anisotropy field by using the inverse effect of magnetostriction; the spin orbit torque layer is used for overturning the magnetization direction of a free layer in the magnetic tunnel junction under the action of a magnetic anisotropy field; the magnetic tunnel junction comprises a free layer and a reference layer, wherein a barrier tunneling layer is arranged between the free layer and the reference layer, and the magnetic tunnel junction records information through the magnetization direction of the free layer; a protective layer for preventing oxidation or corrosion of the tunnel junction; CoFe2O4The layer is used for reducing the current shunting effect of the spin-orbit torque layer during writing, and CoFe2O4The load is applied, the inverse effect of magnetostriction is utilized to provide an in-plane magnetic anisotropy field, the in-plane magnetic anisotropy field is used for providing an external magnetic field required by magnetic reversal for the free layer, the magnetic reversal magnetic moment is driven by the spin orbit torque without the external field, the reversal current is reduced, and the power consumption is reduced.
Description
Technical Field
The invention relates to the technical field of magnetic memories, in particular to a device for driving magnetic flip magnetic moment by spin orbit torque without an external field and a preparation method thereof.
Background
With the development of computer technology, it has been difficult to maintain moore's law by the progress of semiconductor processes alone. Therefore, the method for improving the performance by compensating the short board in the current computer system through structural change and introducing new principles and devices becomes a well-known and feasible method. In current computer architectures, the main bottleneck limiting the increase in computing performance is memory. For this reason, a number of new memory technologies have been proposed and are being extensively studied, such as phase change memory (PRAM), ferroelectric memory (FeRAM), Resistive Random Access Memory (RRAM), and magnetic memory (MAM), to which the present invention relates.
Current magnetic hard disk storage technology is gradually evolving from the beginning of low efficiency magnetic tapes or disks by increasing the sensitivity and efficiency of read and write heads. This mode of recording information using magnetism has been evolving to develop into the Hard Disk Drive (HDD) of today. In recent years, the speed of HDDs has been greatly increased by Solid State Disks (SSD) using NAND Flash, and even due to the reduction of the process, the advantages of large capacity and high density originally have been traced. Subsequently, MRAM structures are proposed that use the oersted field generated by the current to change the magnetization direction of the free layer in Spin Valves (SVs) or tunnel magnetic junctions (MTJs) by using the resistance difference generated by the giant magnetoresistance effect (GMR) or tunneling magnetoresistance effect (TMR). However, the operating range of the oersted field is too large to be restricted, and the magnetization direction of the neighboring cell is easily affected, which causes a problem of scalability. And later methods that use the spin transfer torque effect (STT) of spin current to flip the free layer overcome this drawback. A series of problems arise with barrier layers due to the need to pass through an ultra-thin tunnel barrier layer of about 1nm of the MTJ for both reading and writing. First, an excessively thick barrier layer greatly increases the bias voltage for the write current, and consumes excessive power. Then too thin barrier layers can reduce the perpendicular anisotropy (PMA) and Tunneling Magnetoresistance (TMR) effects of the free layer, causing instability of the MRAM. The above-described shortcomings of STT-MRAM are well addressed by studies of Spin Orbit Torque (SOT) technology. SOT-MRAM uses spin current (or spin accumulation) generated by Spin Hall Effect (SHE) in heavy metals and Rashba effect (spin-orbit coupling effect) at the boundary to flip the adjacent free layer, thus eliminating the need to deliberately pass current through the MTJ and thus separating the write and read paths. However, the conventional SOT structure needs to additionally add an external magnetic field to realize magnetic inversion under the action of the external magnetic field.
Disclosure of Invention
In order to solve the technical scheme, the invention discloses a device for driving magnetic overturning magnetic moment by external field-free spin orbit moment, which can realize magnetic overturning without additionally arranging an external field auxiliary SOT structure, reduce working current and reduce power consumption, and has the following specific scheme.
The invention discloses a device for driving magnetic flip magnetic moment by external field-free spin orbit moment, which sequentially comprises the following components from bottom to top:
a substrate;
functional layer comprising CoFe2O4Layer of said CoFe2O4The layer provides an in-plane magnetic anisotropy field by using the inverse effect of magnetostriction;
the spin orbit torque layer is used for overturning the magnetization direction of a free layer in the magnetic tunnel junction under the action of the magnetic anisotropy field;
the magnetic tunnel junction comprises the free layer and a reference layer, a barrier tunneling layer is arranged between the free layer and the reference layer, and the magnetic tunnel junction is used for recording information through the magnetization direction of the free layer;
a protective layer for preventing oxidation or corrosion of the MTJ;
wherein, the CoFe2O4The layer is used to reduce the current shunting effect of the spin-orbit torque layer during writing.
According to some embodiments of the invention, the functional layer further comprises a stress enhancement layer comprising any one or a combination of: BiFeO3Layer, SrTiO3Layer, or SiGexA layer for enhancing the CoFe2O4Thermal stability of the layer, and increasing the strength of the magnetic anisotropy field.
According to some embodiments of the invention, the functional layer has a thickness of 1nm to 600nm, and the CoFe is2O4The thickness of the layer is 1nm-500 nm.
According to some embodiments of the invention, the substrate has a thickness of 300 μm to 500 μm, the substrate comprising any one of: si, SiO2、MgO、Al2O3、BiFeO3Or SrTiO3。
According to some embodiments of the invention, the spin orbit torque layer comprises any one or an alloy of: pt, Ta, W, BiSex、BiTexOr WPtx。
According to some embodiments of the invention, the reference layer comprises a CoFeB layer, the free layer comprises a CoFeB layer, and the barrier tunneling layer comprises a MgO layer having a thickness of 1nm to 5 nm.
The invention also discloses a preparation method of the device for driving the magnetic flip magnetic moment by the spin orbit torque without the external field, which comprises the following steps:
growing a functional layer on a substrate, the functional layer comprising CoFe2O4Layer of said CoFe2O4The layer is used for providing an in-plane magnetic anisotropy field by utilizing the inverse effect of magnetostriction;
growing a spin-orbit torque layer on the functional layer, wherein the spin-orbit torque layer is used for reversing the magnetization direction of a ferromagnetic layer in the magnetic tunnel junction under the action of the magnetic anisotropy field;
growing the MTJ on the spin-orbit torque layer, wherein the MTJ comprises the free layer and a reference layer, a barrier tunneling layer is disposed between the free layer and the reference layer, and the MTJ is configured to record information through a magnetization direction of the free layer;
depositing a protective layer over the tunnel junction, the protective layer for preventing oxidation or corrosion of the tunnel junction;
carrying out glue homogenizing, photoetching or exposure through an electron beam exposure system on the protective layer, and developing to manufacture a mask with a preset pattern;
and etching the structure of the device based on the mask, depositing the protective layer for the second time, and depositing an electrode structure.
According to some embodiments of the invention, the functional layer further comprises a stress enhancement layer comprising any one or a combination of: BiFeO3Layer, SrTiO3Layer, or SiGexA layer for enhancing the CoFe2O4Thermal stability of the layer, and increasing the strength of the magnetic anisotropy field.
According to some embodiments of the invention, the functional layer is grown on the substrate by physical vapor deposition.
According to some embodiments of the invention, the CoFe is grown2O4After the layer, for the CoFe2O4Annealing the layer to strengthen the CoFe2O4The strength of the in-plane magnetic anisotropy field provided by the layer.
The invention adopts the technical scheme that CoFe is utilized2O4The material has larger magnetostriction performance through CoFe2O4The load is applied, the inverse effect of magnetostriction is utilized to provide an in-plane magnetic anisotropy field, the in-plane magnetic anisotropy field is used for providing magnetic overturning power for the spin orbit torque layer, the spin orbit torque without the external field drives the magnetic overturning magnetic moment, the overturning current is reduced, and the power consumption is reduced. Furthermore, CoFe2O4The conductive material is an insulating material, so that the current shunt effect in the writing process of the spin orbit torque layer can be reduced, the working current is reduced, and the power consumption is reduced.
Drawings
FIG. 1 is a schematic diagram of a device for driving a magnetic switching moment without an external field spin orbit torque according to an embodiment of the invention;
FIG. 2 is a flow chart that schematically illustrates a method for fabricating a device for driving a magnetic switching moment without an external field spin-orbit torque, in accordance with an embodiment of the present invention;
FIG. 3 is a schematic flow chart illustrating a method for fabricating a device for driving a magnetic flip moment without an external field spin orbit torque according to an embodiment of the present invention;
FIG. 4 is a SEM diagram of a device for driving a magnetic flip moment without an external field spin-orbit moment according to an embodiment of the invention;
FIG. 5 is a graph schematically illustrating electrical test results for a device having a magnetic flip moment driven by an external field spin orbit torque without an external field according to an embodiment of the present invention;
FIG. 6 is a graph schematically illustrating current-driven flop test results for a device without an external field spin orbit torque driving magnetic flop magnetic moment, in accordance with an embodiment of the present invention.
Detailed Description
In order that the objects, technical solutions and advantages of the present invention will become more apparent, the present invention will be further described in detail with reference to the accompanying drawings in conjunction with the following specific embodiments.
It is to be understood that such description is merely illustrative and not intended to limit the scope of the present invention. In the following detailed description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the embodiments of the invention. It may be evident, however, that one or more embodiments may be practiced without these specific details. Furthermore, in the following description, descriptions of well-known technologies are omitted so as to avoid unnecessarily obscuring the concepts of the present invention.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "comprising" as used herein indicates the presence of the features, steps, operations but does not preclude the presence or addition of one or more other features.
All terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art unless otherwise defined. It is noted that the terms used herein should be interpreted as having a meaning consistent with the context of the specification and should not be interpreted in an idealized or overly formal sense, such as, for example, magnetostrictive, meaning that an object, when magnetized in a magnetic field, elongates or contracts in the direction of magnetization and changes significantly in size when the current through the coil changes or the distance from the magnet changes; the magnetostriction effect refers to the effect that the geometric dimension of a magnetic substance is reversibly changed due to the change of the condition of an external magnetic field in the magnetization process; the magnetostriction reverse effect means that the size of a magnetic substance changes under the action of load to generate a magnetic field; as another example, cobalt ferrite (chemical formula CoFe)2O4) It is a magnetostrictive material with coercive force and resistivity several tens times higher than that of magnetic alloy, high-frequency magnetic permeability and magnetocrystalline anisotropy as high as 2.7X 105 J.m-3。
In order to realize the SOT-MRAM, the Hall angle of the spin Hall effect and the Rashba interface effect are improved on one hand, and an external field parallel to a current applied in the process of turning the SOT structure is replaced on the other hand.
In order to solve the technical scheme, the invention discloses a device for driving magnetic flip magnetic moment by spin orbit moment without an external field, which can realize magnetic flip of MTJ without additionally arranging an external field auxiliary SOT structure, reduce working current and reduce power consumption, and has the following specific scheme.
Fig. 1 schematically shows a structural diagram of a device for driving a magnetic switching magnetic moment by an external field-free spin-orbit torque according to an embodiment of the present invention.
According to some embodiments of the present invention, the present invention discloses a device for driving magnetic flip moment without external field spin orbit moment, as shown in fig. 1, the device comprises, from bottom to top: a substrate, a functional layer, a spin-orbit torque layer, a magnetic tunnel junction, and a protective layer.
According to some embodiments of the present invention, the substrate includes a ceramic substrate, a resin substrate, a metal or metal matrix composite, and the like.
According to some embodiments of the invention, the substrate has good electrical insulation and is a substrate for carrying the device structure.
According to some embodiments of the invention, the substrate comprises any one of: si, SiO2、MgO、Al2O3、BiFeO3Or SrTiO3。
According to some embodiments of the invention, the substrate has a thickness of 300 μm to 500 μm.
According to some embodiments of the invention, the functional layer comprises CoFe2O4Layer of CoFe2O4The layer provides an in-plane magnetic anisotropy field using the inverse effect of magnetostriction.
According to some embodiments of the invention, the CoFe is under load2O4The layer generates a magnetic field based on the inverse effect of magnetostriction, i.e. provides an in-plane magnetic anisotropy field.
According to some embodiments of the present invention, the spin-orbit torque layer is used to switch the magnetization direction of the free layer in a MTJ under the influence of a magnetic anisotropy field.
According to some embodiments of the invention, a tunneling junction includes a free layer and a reference layer with a barrier tunneling layer disposed therebetween, the tunneling junction for recording information by a magnetization direction of the free layer.
According to some embodiments of the present invention, the functional layer cooperates with the SOT layer to change the magnetization direction of the free layer, i.e., to write data.
According to some embodiments of the present invention, reading of data is achieved by reading the magnetization direction of the free layer.
According to some embodiments of the invention, the CoFe-based material is selected from the group consisting of Cu, Fe, Cu, and Cu2O4The insulation of the layer can reduce the current shunt effect of the SOT layer in the writing process, and the energy consumption of the SOT-MRAM is reduced.
According to some embodiments of the invention, CoFe2O4The preparation process of the layer and the SOT layer is compatible with the preparation process of the MTJ, so that the production efficiency is improved, and the production cost is reduced.
According to some embodiments of the invention, the CoFe-based material is selected from the group consisting of Cu, Fe, Cu, and Cu2O4The inverse effect of the magnetostriction of the layer can pin the magnetic moment direction of the ferromagnetic layer, so that a magnetic field can be stably provided, and the stability of a free layer in the magnetic tunnel junction can be improved.
According to some embodiments of the invention, the CoFe is annealed by a thermal annealing apparatus2O4The layer is thermally annealed to increase the CoFe content2O4The coercive force of the layer further improves the strength of the in-plane magnetic anisotropy field.
According to some embodiments of the invention, the reference layer comprises a CoFeB layer, the free layer comprises a CoFeB layer, and the barrier tunneling layer comprises a MgO layer. The specific principle of mtj is the prior art and is not the invention of the present application, and those skilled in the art can obtain the mtj by referring to the relevant information, and will not be described in detail herein.
According to some embodiments of the present invention, the MgO layer has a thickness of 1nm to 5nm to ensure that the resistance of the MTJ is within a range readable by the power control circuit.
According to some embodiments of the present invention, it is preferable that the thickness of the MgO layer is 1nm, and the resistance of the read mtj is accurate.
According to some embodiments of the present invention, the protective layer is used to prevent oxidation or corrosion of the MTJ layer.
According to some embodiments of the invention, the protective layer comprises any one or a combination of: SiO 22、AlOxTaN, TiN or MgO.
According to some embodiments of the invention, the protective layer is deposited by magnetron sputtering or electron beam evaporation.
According to some embodiments of the invention, the protective layer has a thickness of 1-500 nm.
According to some embodiments of the invention, the protective layer with a thickness of 50nm has a good effect, and can save materials and reduce the processing difficulty as much as possible while ensuring sufficient protective capability.
According to some embodiments of the invention, the functional layer further comprises a stress enhancement layer.
According to some embodiments of the invention, the stress enhancement layer comprises any one or a combination of: BiFeO3Layer, SrTiO3Layer, or SiGexAnd (3) a layer.
According to some embodiments of the invention, the stress enhancement layer is used to enhance CoFe2O4Thermal stability of the layer.
According to some embodiments of the invention, a stress enhancement layer is used to assist the CoFe2O4The layer provides a magnetic anisotropy field, and particularly can improve the strength of the magnetic anisotropy field, so that the capability of the SOT layer for switching the magnetization direction of the free layer is improved.
According to some embodiments of the invention, the functional layer has a thickness of 1nm to 600nm, CoFe2O4The thickness of the layer is 1nm-500 nm.
According to some embodiments of the invention, CoFe2O4The effect of stress is more pronounced the thinner the layer thickness, but too thin CoFe2O4The layer cannot guarantee its magnetostrictive effect.
According to some embodiments of the invention, CoFe2O4The effect is better when the thickness of the layer is 15 nm.
According to some embodiments of the invention，CoFe2O4The total thickness of the layer and the stress enhancement layer is not more than 600 nm.
According to some embodiments of the present invention, the stress enhancement layer has a thickness of 10nm, which is preferable, and not only can ensure sufficient amplification, but also can keep the production cost low.
According to some embodiments of the invention, the spin orbit torque layer comprises any one or an alloy of: pt, Ta, W, BiSex、BiTexOr WPtx。
According to some embodiments of the invention, the spin-orbit torque layer is grown by magnetron sputtering or electron beam evaporation.
Fig. 4 schematically illustrates an SEM image of a device with no external field spin orbit torque driving magnetic flip moment according to some embodiments of the present invention, and fig. 4 illustrates an electron microscope image of the device, from which it can be seen that the size of the device provided by the present invention is in the micrometer scale.
Fig. 2 schematically shows a flowchart of a method for manufacturing a device for driving a magnetic flip moment without an external field spin orbit moment according to an embodiment of the present invention, and fig. 3 schematically shows a flowchart of a method for manufacturing a device for driving a magnetic flip moment without an external field spin orbit moment according to an embodiment of the present invention.
The invention also discloses a preparation method of the device for driving the magnetic flip magnetic moment by the spin orbit torque without the external field, which comprises the steps of S1 to S6 as shown in FIG. 2 and FIG. 3.
According to some embodiments of the invention, step S1: a functional layer is grown on a substrate.
According to some embodiments of the present invention, the substrate includes a ceramic substrate, a resin substrate, a metal or metal matrix composite, and the like.
According to some embodiments of the invention, the substrate has good electrical insulation and is a substrate for carrying the structure of the device.
According to some embodiments of the invention, the substrate comprises any one of: si, SiO2、MgO、Al2O3、BiFeO3Or SrTiO3。
According to some embodiments of the invention, the substrate is grown to a thickness of 300 μm to 500 μm.
According to some embodiments of the invention, the functional layer comprises CoFe2O4Layer of CoFe2O4The layers are used to provide an in-plane magnetic anisotropy field using the inverse effect of magnetostriction.
According to some embodiments of the invention, the functional layer comprises CoFe2O4Layer of CoFe2O4The layer provides an in-plane magnetic anisotropy field using the inverse effect of magnetostriction.
According to some embodiments of the invention, the CoFe is under load2O4The layer provides an in-plane magnetic anisotropy field based on the inverse effect of magnetostriction.
According to some embodiments of the invention, step S2: and growing a spin orbit torque layer on the functional layer.
According to some embodiments of the present invention, the spin-orbit torque layer is used to switch the magnetization direction of the ferromagnetic layer in a MTJ under the influence of a magnetic anisotropy field.
According to some embodiments of the invention, step S3: a magnetic tunnel junction is grown on the spin-orbit torque layer.
According to some embodiments of the invention, a tunneling junction includes a free layer and a reference layer with a barrier tunneling layer disposed therebetween, the tunneling junction for recording information by a magnetization direction of the free layer.
According to some embodiments of the present invention, the functional layer cooperates with the SOT layer to change the magnetization direction of the free layer, i.e., to write data.
According to some embodiments of the present invention, reading of data is achieved by reading the magnetization direction of the free layer.
According to some embodiments of the invention, the CoFe-based material is selected from the group consisting of Cu, Fe, Cu, and Cu2O4The insulation of the layer can reduce the current shunt effect of the SOT layer in the writing process, and the energy consumption of the SOT-MRAM is reduced.
According to some embodiments of the invention, CoFe2O4The layers and SOT layers are fabricated in a process that is compatible with the MTJ layers,the production efficiency is improved, and the production cost is reduced.
According to some embodiments of the invention, the CoFe-based material is selected from the group consisting of Cu, Fe, Cu, and Cu2O4The inverse effect of the magnetostriction of the layer may improve the stability of the free layer in the mtj.
According to some embodiments of the invention, the CoFe is annealed by a thermal annealing apparatus2O4The layer is thermally annealed to increase the CoFe content2O4The coercive force of the layer further improves the strength of the in-plane magnetic anisotropy field.
According to some embodiments of the invention, step S4: a protective layer is deposited over the tunnel junction, the protective layer serving to protect the tunnel junction from oxidation or corrosion.
According to some embodiments of the present invention, the protective layer is used to prevent oxidation or corrosion of the MTJ layer.
According to some embodiments of the invention, the protective layer comprises any one or a combination of: SiO 22、AlOxTaN, TiN or MgO.
According to some embodiments of the invention, the protective layer is deposited by magnetron sputtering or electron beam evaporation.
According to some embodiments of the invention, the protective layer has a thickness of 1-500 nm.
According to some embodiments of the invention, the protective layer has a thickness of 200nm, 300nm or 400 nm.
According to some embodiments of the invention, step S5: and (3) coating photoresist on the protective layer, carrying out photoetching or exposure through an electron beam exposure system, and developing to prepare a mask with a preset pattern.
According to some embodiments of the invention, step S6: and etching the structure of the device based on the mask, secondarily depositing a protective layer and depositing an electrode structure.
According to some embodiments of the present invention, the protective layer is deposited twice in order to prevent the structure of the device from being damaged during the manufacturing process.
According to some embodiments of the invention, the functional layer further comprises a stress enhancement layer comprising any one or a combination of: BiFeO3Layer, SrTiO3Layer, or SiGexLayer, stress enhancement layer for CoFe enhancement2O4Thermal stability of the layer, and increasing the strength of the magnetic anisotropy field.
According to some embodiments of the invention, the functional layer is grown on the substrate by physical vapor deposition.
FIG. 5 is a graph schematically illustrating electrical test results for a device having a magnetic flip moment driven by an external field spin orbit torque without an external field according to an embodiment of the present invention; FIG. 6 is a graph schematically illustrating current driven flop test results for a device without an external field spin orbit torque driven magnetic flop magnetic moment, in accordance with an embodiment of the present invention.
According to some embodiments of the present invention, as shown in FIG. 5, a device CoFe is provided for the present invention2O4The results of the anisotropic magnetoresistance test of the CoFeB ferromagnetic layer grown on the material, specifically, the changes of the resistance and the in-plane and out-plane magnetic fields were measured by using four probes, and it can be seen from the results of FIG. 5 that CoFe2O4The material induces an in-plane magnetic field in the CoFeB layer.
According to some embodiments of the present invention, as shown in fig. 6, the test results of current-driven magnetic switching (using the hall bar structure as shown in fig. 4) for the device provided by the present invention, specifically, applying a current to the horizontal hall bar and measuring a voltage on the vertical hall bar, show that the current through the SOT layer drives the switching of the magnetization direction of the ferromagnetic layer in the absence of an external magnetic field.
For the graph of the magnetization intensity of the device provided by the invention under the action of current, the magnetization direction of the free layer in the MTJ is reversed by adopting the current.
The invention adopts the technical scheme that CoFe is utilized2O4The material has larger magnetostriction performance through CoFe2O4The load is applied, the in-plane magnetic anisotropy field is provided by using the inverse effect of magnetostriction, the in-plane magnetic anisotropy field is used for providing magnetic flip power for the spin orbit torque layer, the spin orbit torque without an external field drives the magnetic flip magnetic moment, the flip current is reduced, and the power consumption is reduced. Furthermore, CoFe2O4Is a ferromagnetic material, and isThe insulating material can reduce the current shunting effect in the writing process of the spin orbit torque layer, reduce the working current and reduce the power consumption.
Using CoFe2O4The magnetostriction reverse effect can pin the magnetic moment direction of the ferromagnetic layer, so that a magnetic field is more stably provided, and the integral robustness of the device can be improved.
The device structure and the process flow provided by the invention can be well compatible with the current semiconductor process, and the practicability is stronger.
So far, the embodiments of the present disclosure have been described in detail with reference to the accompanying drawings. It is to be noted that, in the attached drawings or in the description, the implementation modes not shown or described are all the modes known by the ordinary skilled person in the field of technology, and are not described in detail. In addition, the above definitions of the components are not limited to the specific structures, shapes or manners mentioned in the embodiments, and those skilled in the art may easily modify or replace them.
It is also noted that, unless otherwise indicated, the numerical parameters set forth in the specification and attached claims are approximations that can vary depending upon the desired properties sought to be obtained by the present disclosure. In particular, all numbers expressing dimensions, range conditions, and so forth, used in the specification and claims are to be understood as being modified in all instances by the term "about". Generally, the expression is meant to encompass variations of ± 10% in some embodiments, 5% in some embodiments, 1% in some embodiments, 0.5% in some embodiments by the specified amount.
It will be appreciated by a person skilled in the art that various combinations and/or combinations of features described in the various embodiments and/or in the claims of the invention are possible, even if such combinations or combinations are not explicitly described in the invention. In particular, various combinations and/or combinations of the features recited in the various embodiments and/or claims of the present invention may be made without departing from the spirit or teaching of the invention. All such combinations and/or associations are within the scope of the present invention.
The above-mentioned embodiments are intended to illustrate the objects, technical solutions and advantages of the present invention in further detail, and it should be understood that the above-mentioned embodiments are only exemplary embodiments of the present invention and are not intended to limit the present invention, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (10)
1. The utility model provides a device of no external field spin orbit moment drive magnetic flip moment of magnetization which characterized in that, the device includes from bottom to top in proper order:
a substrate;
functional layer comprising CoFe2O4Layer of said CoFe2O4The layer provides an in-plane magnetic anisotropy field by using the inverse effect of magnetostriction;
the spin orbit torque layer is used for overturning the magnetization direction of a free layer in the magnetic tunnel junction under the action of the magnetic anisotropy field;
the magnetic tunnel junction comprises the free layer and a reference layer, a barrier tunneling layer is arranged between the free layer and the reference layer, and the magnetic tunnel junction is used for recording information through the magnetization direction of the free layer;
a protective layer for preventing oxidation or corrosion of the MTJ;
wherein, the CoFe2O4The layer is used to reduce the current shunting effect of the spin-orbit torque layer during writing.
2. The device of claim 1, wherein the functional layer further comprises a stress enhancement layer comprising any one or a combination of: BiFeO3Layer, SrTiO3A layer, or SiGex layer, the stress enhancement layer for increasing the CoFe2O4Thermal stability of the layer, and increasing the strength of the magnetic anisotropy field.
3. Device according to claim 1 or 2, characterized in that the thickness of the functional layer is between 1nm and 600nm, the CoFe2O4The thickness of the layer is 1nm-500 nm.
4. The device according to claim 1 or 2, wherein the substrate has a thickness of 300 μm to 500 μm, the substrate comprising either: si, SiO2、MgO、Al2O3、BiFeO3Or SrTiO3。
5. The device of claim 1 or 2, wherein the spin-orbit torque layer comprises any one or an alloy of: pt, Ta, W, BiSex、BiTexOr WPtx。
6. The device of claim 1 or 2, wherein the reference layer comprises a CoFeB layer, the free layer comprises a CoFeB layer, and the barrier tunneling layer comprises a MgO layer having a thickness of 1nm-5 nm.
7. A preparation method of a device for driving magnetic flip magnetic moment by spin orbit torque without external field is characterized by comprising the following steps:
growing a functional layer on a substrate, the functional layer comprising CoFe2O4Layer of said CoFe2O4The layer is used for providing an in-plane magnetic anisotropy field by utilizing the inverse effect of magnetostriction;
growing a spin-orbit torque layer on the functional layer, wherein the spin-orbit torque layer is used for reversing the magnetization direction of a ferromagnetic layer in the magnetic tunnel junction under the action of the magnetic anisotropy field;
growing the MTJ on the spin-orbit torque layer, wherein the MTJ comprises a free layer and a reference layer, a barrier tunneling layer is disposed between the free layer and the reference layer, and the MTJ is configured to record information through a magnetization direction of the free layer;
depositing a protective layer over the tunnel junction, the protective layer for preventing oxidation or corrosion of the tunnel junction;
carrying out glue homogenizing, photoetching or exposure through an electron beam exposure system and developing on the protective layer to manufacture a mask with a preset pattern;
and etching the structure of the device based on the mask, depositing the protective layer for the second time, and depositing an electrode structure.
8. The method of claim 7, wherein the functional layer further comprises a stress enhancement layer comprising any one or a combination of: BiFeO3Layer, SrTiO3A layer, or SiGex layer, the stress enhancement layer for increasing the CoFe2O4Thermal stability of the layer, and increasing the strength of the magnetic anisotropy field.
9. The method according to claim 7 or 8, wherein the functional layer is grown on the substrate by physical vapor deposition.
10. The method according to claim 7 or 8, wherein the CoFe is growing2O4After layering, for the CoFe2O4Annealing the layer to strengthen the CoFe2O4The strength of the in-plane magnetic anisotropy field provided by the layer.
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| WO2017034564A1 (en) * | 2015-08-26 | 2017-03-02 | Intel Corporation | Single pulse magneto-strictive switching via hybrid magnetization stack |
| CN106688041A (en) * | 2014-09-25 | 2017-05-17 | 英特尔公司 | Strain assisted spin torque switching spin transfer torque memory |
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| CN106688041A (en) * | 2014-09-25 | 2017-05-17 | 英特尔公司 | Strain assisted spin torque switching spin transfer torque memory |
| WO2017034564A1 (en) * | 2015-08-26 | 2017-03-02 | Intel Corporation | Single pulse magneto-strictive switching via hybrid magnetization stack |
| WO2017214628A1 (en) * | 2016-06-10 | 2017-12-14 | Cornell University | Semiconductor circuits and devices based on low-energy consumption semiconductor structures exhibiting multi-valued magnetoelectric spin hall effect |
| WO2019005173A1 (en) * | 2017-06-30 | 2019-01-03 | Intel Corporation | Magnetostrictive logic with unipolar piezoelectric stack |
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