CN117577445A - Method for realizing spin orbit moment without external magnetic field, multilayer film structure, hall rod and magnetic random access memory - Google Patents
Method for realizing spin orbit moment without external magnetic field, multilayer film structure, hall rod and magnetic random access memory Download PDFInfo
- Publication number
- CN117577445A CN117577445A CN202210936818.9A CN202210936818A CN117577445A CN 117577445 A CN117577445 A CN 117577445A CN 202210936818 A CN202210936818 A CN 202210936818A CN 117577445 A CN117577445 A CN 117577445A
- Authority
- CN
- China
- Prior art keywords
- layer
- moment
- ferromagnetic layer
- film structure
- multilayer film
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 230000005291 magnetic effect Effects 0.000 title claims abstract description 43
- 238000000034 method Methods 0.000 title claims abstract description 34
- 230000005294 ferromagnetic effect Effects 0.000 claims abstract description 113
- 229910052760 oxygen Inorganic materials 0.000 claims abstract description 32
- 239000001301 oxygen Substances 0.000 claims abstract description 32
- -1 oxygen ions Chemical class 0.000 claims abstract description 27
- 125000004430 oxygen atom Chemical group O* 0.000 claims abstract description 23
- 230000000694 effects Effects 0.000 claims abstract description 17
- 230000003647 oxidation Effects 0.000 claims abstract description 16
- 238000007254 oxidation reaction Methods 0.000 claims abstract description 16
- 230000008859 change Effects 0.000 claims abstract description 4
- 239000000463 material Substances 0.000 claims description 36
- 229910052751 metal Inorganic materials 0.000 claims description 27
- 239000002184 metal Substances 0.000 claims description 27
- 238000003780 insertion Methods 0.000 claims description 25
- 230000037431 insertion Effects 0.000 claims description 25
- 230000005012 migration Effects 0.000 claims description 14
- 238000013508 migration Methods 0.000 claims description 14
- 238000004544 sputter deposition Methods 0.000 claims description 13
- 239000000758 substrate Substances 0.000 claims description 10
- 229910019236 CoFeB Inorganic materials 0.000 claims description 5
- 238000000137 annealing Methods 0.000 claims description 5
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 5
- 238000002360 preparation method Methods 0.000 claims description 5
- 229910001385 heavy metal Inorganic materials 0.000 claims description 4
- 239000011810 insulating material Substances 0.000 claims description 4
- 239000007769 metal material Substances 0.000 claims description 4
- 229910003321 CoFe Inorganic materials 0.000 claims description 2
- 229910020068 MgAl Inorganic materials 0.000 claims description 2
- 229910052715 tantalum Inorganic materials 0.000 claims description 2
- 229910052721 tungsten Inorganic materials 0.000 claims description 2
- 229910052735 hafnium Inorganic materials 0.000 claims 1
- 229910052750 molybdenum Inorganic materials 0.000 claims 1
- 230000000284 resting effect Effects 0.000 claims 1
- 238000013016 damping Methods 0.000 abstract description 5
- 239000010408 film Substances 0.000 description 31
- 230000001105 regulatory effect Effects 0.000 description 16
- 238000005516 engineering process Methods 0.000 description 13
- 239000002120 nanofilm Substances 0.000 description 13
- 238000009396 hybridization Methods 0.000 description 6
- 230000015654 memory Effects 0.000 description 6
- 238000010586 diagram Methods 0.000 description 5
- 238000012545 processing Methods 0.000 description 5
- 230000001276 controlling effect Effects 0.000 description 4
- 230000010287 polarization Effects 0.000 description 4
- 239000000243 solution Substances 0.000 description 4
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 3
- 238000000151 deposition Methods 0.000 description 3
- 230000008021 deposition Effects 0.000 description 3
- 238000005566 electron beam evaporation Methods 0.000 description 3
- 230000005415 magnetization Effects 0.000 description 3
- 238000001755 magnetron sputter deposition Methods 0.000 description 3
- 238000001259 photo etching Methods 0.000 description 3
- 239000004065 semiconductor Substances 0.000 description 3
- 229910052814 silicon oxide Inorganic materials 0.000 description 3
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 2
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 2
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 2
- 230000008901 benefit Effects 0.000 description 2
- 238000012512 characterization method Methods 0.000 description 2
- 230000000295 complement effect Effects 0.000 description 2
- 229910044991 metal oxide Inorganic materials 0.000 description 2
- 150000004706 metal oxides Chemical class 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 229910052710 silicon Inorganic materials 0.000 description 2
- 239000010703 silicon Substances 0.000 description 2
- 239000010409 thin film Substances 0.000 description 2
- 238000012546 transfer Methods 0.000 description 2
- 230000007306 turnover Effects 0.000 description 2
- 229910005900 GeTe Inorganic materials 0.000 description 1
- 238000000231 atomic layer deposition Methods 0.000 description 1
- 230000004888 barrier function Effects 0.000 description 1
- 230000033228 biological regulation Effects 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 230000001808 coupling effect Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 238000013135 deep learning Methods 0.000 description 1
- 239000008367 deionised water Substances 0.000 description 1
- 229910021641 deionized water Inorganic materials 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000001312 dry etching Methods 0.000 description 1
- 230000009977 dual effect Effects 0.000 description 1
- 230000002708 enhancing effect Effects 0.000 description 1
- 238000005530 etching Methods 0.000 description 1
- 230000005284 excitation Effects 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 238000010884 ion-beam technique Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000001451 molecular beam epitaxy Methods 0.000 description 1
- 238000004088 simulation Methods 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 230000005641 tunneling Effects 0.000 description 1
- 238000004506 ultrasonic cleaning Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F41/00—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties
- H01F41/14—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for applying magnetic films to substrates
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F10/00—Thin magnetic films, e.g. of one-domain structure
- H01F10/08—Thin magnetic films, e.g. of one-domain structure characterised by magnetic layers
- H01F10/10—Thin magnetic films, e.g. of one-domain structure characterised by magnetic layers characterised by the composition
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F10/00—Thin magnetic films, e.g. of one-domain structure
- H01F10/08—Thin magnetic films, e.g. of one-domain structure characterised by magnetic layers
- H01F10/10—Thin magnetic films, e.g. of one-domain structure characterised by magnetic layers characterised by the composition
- H01F10/12—Thin magnetic films, e.g. of one-domain structure characterised by magnetic layers characterised by the composition being metals or alloys
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F41/00—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties
- H01F41/14—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for applying magnetic films to substrates
- H01F41/30—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for applying magnetic films to substrates for applying nanostructures, e.g. by molecular beam epitaxy [MBE]
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F41/00—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties
- H01F41/14—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for applying magnetic films to substrates
- H01F41/30—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for applying magnetic films to substrates for applying nanostructures, e.g. by molecular beam epitaxy [MBE]
- H01F41/301—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for applying magnetic films to substrates for applying nanostructures, e.g. by molecular beam epitaxy [MBE] for applying ultrathin or granular layers
Abstract
The invention provides a method for realizing spin orbit moment without an external magnetic field, a multilayer film structure, a Hall rod and a magnetic random access memory. The method is to change the ratio of the quasi-field moment to the quasi-damping moment in the spin orbit moment by utilizing the oxidation engineering effect on the multilayer film structure; the use of oxidation engineering effects to vary the magnitude of the ratio of field-like moment to damping-like moment in spin-orbit torque is achieved by affecting the non-ferromagnetic layer with oxygen atoms and/or oxygen ions, comprising: after the multilayer film structure is prepared, standing is performed, or a voltage is applied between the oxide layer and the ferromagnetic layer, so that oxygen atoms and/or oxygen ions migrate to the interface between the non-ferromagnetic layer and the ferromagnetic layer. The invention changes the ratio of the field-like moment to the damping-like moment in the spin orbit moment by utilizing the oxidation engineering effect, and simultaneously utilizes the extra out-of-plane spin orbit moment to generate the in-plane bias field, thereby finally realizing the magnetic moment overturning without a magnetic field, and having simple structure and simple and convenient operation.
Description
Technical Field
The invention relates to the technical field of magnetic random access memories, in particular to a method for improving spin orbit torque overturning efficiency of a multilayer film structure, the multilayer film structure, a Hall rod and a magnetic random access memory.
Background
With the continuous development of complementary metal oxide semiconductor (Complementary Metal Oxide Semiconductor, CMOS) technology, conventional memories based on semiconductors encounter power consumption bottlenecks, which inevitably generate large static power consumption due to leakage currents. Magnetic random access memory (Magnetic Random Access Memory, MRAM) with non-volatile, high performance, low power consumption is considered an efficient and promising solution. In addition, the memory has good compatibility with the CMOS post-process, so the memory can be applied to a traditional computer storage system and can be expanded to other emerging computing fields such as deep learning, probability computing and the like. The basic memory cell in a magnetic random access memory is called a magnetic tunnel junction (Magnetic Tunnel Junction, MTJ) which consists of two ferromagnetic layers with a tunneling barrier layer sandwiched between them. One of the ferromagnetic layers is called a reference layer, the magnetization direction of which is unchanged; the other ferromagnetic layer is called the free layer, and the magnetization direction is parallel or antiparallel to the reference layer, thereby realizing the low resistance state and the high resistance state of the magnetic tunnel junction, and can be represented by binary numbers of "0" and "1".
Currently, the main magnetic random access memory writing method is as follows: spin-Transfer Torque (STT) and Spin-Orbit Torque (SOT). The spin orbit moment is to add a layer of non-ferromagnetic layer below the ferromagnetic layer, input charge flow to the non-ferromagnetic layer, generate self-rotational flow in the non-ferromagnetic layer through spin orbit coupling effect, and make the magnetic moment in the ferromagnetic layer achieve the purpose of magnetic inversion by using the spin orbit moment induced by the self-rotational flow. Compared with spin transfer torque, the spin orbit torque has the advantages of higher speed, higher durability, lower power consumption and the like, and can realize magnetic inversion in the range of nanoseconds or even subnanoseconds.
At present, there are two methods for improving spin-orbit torque flip efficiency: one is to improve the flipping efficiency by regulating the resistivity of the non-ferromagnetic layer, and the other is to insert an ultra-thin light metal layer between the non-ferromagnetic layer and the ferromagnetic layer to modify the effect of interfacial spin transparency, thereby enhancing spin injection. However, the above regulation method has a single advantage because power consumption is increased due to joule heat when a high-resistance material is introduced. Furthermore, during sputter growth, it is often difficult to avoid oxidation of the ferromagnetic layer material, which oxidation is mainly due to energetic oxygen ions of the oxide layer during sputtering, as well as oxygen migration caused after annealing. Thus, there is a large difference from the ideal interface. In view of this, a way of providing an excellent interface and a method of improving spin-orbit torque flip efficiency of a magnetic memory are particularly important.
Disclosure of Invention
In order to solve the above problems, an object of the present invention is to provide a new method for realizing spin orbit torque without external magnetic field, which is to use oxidation engineering effect to realize magnetic moment inversion without magnetic field.
To achieve the above object, in one aspect, the present invention provides a method for achieving spin-orbit torque without an external magnetic field, wherein the method is to change the ratio of the field-like moment to the damping-like moment in the spin-orbit torque by using an oxidation engineering effect on a multilayer film structure, wherein:
the multilayer film structure comprises an oxide layer, a ferromagnetic layer and a nonferromagnetic layer which are sequentially arranged;
the ratio of the field-like moment to the damping-like moment in the spin orbit moment is changed by using oxygen atoms and/or oxygen ions to influence the nonferromagnetic layer, and the method specifically comprises the following steps of: after the multilayer film structure is prepared, standing is performed, so that oxygen atoms and/or oxygen ions migrate to the interface between the nonferromagnetic layer and the ferromagnetic layer, or voltage is applied between the oxide layer and the ferromagnetic layer, so that the oxygen atoms and/or oxygen ions migrate to the interface between the nonferromagnetic layer and the ferromagnetic layer.
According to an embodiment of the present invention, since a thicker magnetic dead layer (thickness of about 0.1 to 0.3 nm) exists in a thinner ferromagnetic layer (thickness of about 1 to 1.2 nm), in this case, oxygen atoms and/or oxygen ions can migrate to the interface between the non-ferromagnetic layer and the ferromagnetic layer during the standing after the multilayer film structure is produced.
According to a specific embodiment of the present invention, preferably, the migration of oxygen atoms and/or oxygen ions includes one or a combination of two or more of migration of high-energy oxygen ions of the oxide layer during sputtering, migration of oxygen atoms in the oxide layer, and oxygen migration caused after annealing.
According to a specific embodiment of the present invention, as the doping of oxygen atoms/oxygen ions acts on the non-ferromagnetic layer, the orbital hybridization of the non-ferromagnetic layer is affected, the interface between the non-ferromagnetic layer and the ferromagnetic layer is further affected, and the ratio of the field-like moment to the damping-like moment is regulated, preferably, the ratio of the field-like moment to the damping-like moment in the spin-orbit moment is-8 to +8, and more preferably +3 to +5.
According to a specific embodiment of the present invention, preferably, when oxygen atoms and/or oxygen ions are migrated by applying a voltage, the applied voltage is-20V to 20V; the time for applying the voltage is 5s-60s.
According to a specific embodiment of the present invention, preferably, the time of rest is around 7 days, for example 7-30 days.
According to a specific embodiment of the present invention, the thickness of the non-ferromagnetic layer is preferably 0.1 to 10nm, preferably 2 to 10nm, more preferably 5 to 10nm.
According to a specific embodiment of the present invention, the material of the non-ferromagnetic layer may be selected from one or a combination of two or more of heavy metal materials or topologically insulating materials, preferably a strong spin-orbit coupling material.
According to a specific embodiment of the present invention, preferably, the heavy metal material is selected from one or a combination of two or more of Ta, pt, W, ir, mo; more preferably Ta.
According to a particular embodiment of the invention, preferably, the topologically insulating material is selected from Bi 2 Se 3 ，Bi 2 Te 3 ，Bi x Sb 1-x ，Sb 2 Te 3 And (Bi) x Sb 1-x ) 2 Te 3 One or a combination of two or more of Bi x Sb 1-x X of (2) may be about 0.9; said (Bi) x Sb 1-x ) 2 Te 3 The value of x in (c) ranges from about 0 to about 1.
According to a specific embodiment of the present invention, preferably, the non-ferromagnetic layer material is attached to the substrate material.
According to a specific embodiment of the present invention, the ferromagnetic layer preferably has a thickness of 0.2 to 2nm, preferably 0.2 to 1.3nm, more preferably 1 to 1.3nm.
According to a specific embodiment of the present invention, the material of the ferromagnetic layer may be selected from one or a combination of two or more of CoFeB, feB, coFe.
According to a specific embodiment of the present invention, preferably, the CoFeB comprises Co 20 Fe 60 B 20 ，Co 40 Fe 40 B 20 Or Co 60 Fe 20 B 20 Etc., where the numbers represent percentages of elements and are not limited to the ratios of elements described herein. Preferably, the CoFeB is Co 20 Fe 60 B 20 。
According to a particular embodiment of the invention, preferably the FeB comprises Fe 80 B 20 Etc., where the numbers represent percentages of elements and are not limited to the ratios of elements described herein.
According to a particular embodiment of the invention, preferably, the CoFe comprises Co 50 Fe 50 ，Co 20 Fe 80 Or Co 80 Fe 20 Etc., where the numbers represent percentages of elements and are not limited to the ratios of elements described herein.
According to a specific embodiment of the present invention, the oxide layer preferably has a thickness of 0.01 to 3.5nm, preferably 1 to 2.5nm, more preferably 2 to 2.5nm.
According to a specific embodiment of the present invention, the material of the oxide layer may be selected from MgO, al 2 O 3 ，MgAl 2 O 4 One or a combination of two or more of them; mgO is preferred.
According to a specific embodiment of the present invention, preferably, an ultra-thin metal insertion layer is provided between the ferromagnetic layer and the oxide layer of the multilayer film structure. The migration amount of oxygen atoms can be regulated by providing an ultra-thin metal insertion layer.
According to a specific embodiment of the present invention, the thickness of the ultra-thin metal insertion layer is preferably 0.01 to 0.8nm, more preferably 0.2 to 0.8nm, and still more preferably 0.2 to 0.6nm. The effect of the oxygen atom content on the non-ferromagnetic layer can be further affected by controlling the thickness of the ultra-thin metal insertion layer.
According to a specific embodiment of the present invention, the material of the ultra-thin metal insertion layer may be selected from one or a combination of two or more of Mg, ti, al, hf; mg is preferred.
According to the specific embodiment of the invention, the ferromagnetic layer, the non-ferromagnetic layer, the ultrathin metal insertion layer and the oxide layer can be grown by a magnetron sputtering technology, molecular beam epitaxy or atomic layer deposition.
The invention also provides application of the method for realizing spin orbit moment without an external magnetic field in preparing an electronic device with a multilayer film structure; preferably, the electronic device is a magnetic random access memory device.
According to some embodiments of the invention, the application comprises growing a multilayer film on silicon oxide, further producing an electronic device by a micro-nano processing operation method.
According to some embodiments of the present invention, the layers of material are grown on a substrate or other multi-layer film in a bottom-to-top order, and the device is then fabricated by conventional micro-nano processing, with each thin film layer having a substantially equal cross-sectional area.
The invention also provides a multilayer film structure comprising a non-ferromagnetic layer, a ferromagnetic layer and an oxide layer arranged in sequence; preferably, an ultrathin metal insertion layer is arranged between the ferromagnetic layer and the oxide layer; the multilayer film structure is prepared by the method for realizing spin orbit moment without external magnetic field.
The invention also provides a Hall rod, which comprises a substrate, a non-ferromagnetic layer, a ferromagnetic layer, an oxide layer and an electrode film layer which are sequentially arranged; preferably, an ultrathin metal insertion layer is arranged between the ferromagnetic layer and the oxide layer; the Hall rod is prepared by the method without external magnetic field spin orbit moment.
The invention also provides a magnetic random access memory which contains the multilayer film structure or the Hall rod.
According to some embodiments of the present invention, the layers of material are grown on a substrate or other multi-layer film in a bottom-to-top order, and the device is then fabricated by conventional micro-nano processing, with each thin film layer having a substantially equal cross-sectional area. The micro-nano processing technology operation method comprises one or more than two of photoetching, ion beam etching and electron beam evaporation.
The invention changes the ratio of the field-like moment to the damping-like moment in the spin orbit moment by utilizing the oxidation engineering effect, and simultaneously utilizes the extra out-of-plane spin orbit moment to generate the in-plane bias field, thereby finally realizing the magnetic moment overturning without a magnetic field, and having simple structure and simple and convenient operation.
Drawings
Fig. 1 is a schematic view of a multilayer nanofilm provided in example 1.
Fig. 2 is a schematic diagram showing the structure breaking symmetry of the multilayer nanofilm of example 1.
Fig. 3 is a schematic diagram of the multilayer nanofilm of example 1 to achieve field-free moment flipping.
FIG. 4 is a schematic diagram of the structure of a regulated multilayer nanofilm in example 2.
Detailed Description
The technical solution of the present invention will be described in detail below for a clearer understanding of technical features, objects and advantageous effects of the present invention, but should not be construed as limiting the scope of the present invention.
Example 1
This embodiment provides a multilayer film structure, the structure of which is shown in fig. 1. The multilayer film structure comprises a non-ferromagnetic layer, a ferromagnetic layer, an ultrathin metal insertion layer and an oxide layer which are sequentially arranged; wherein:
the material of the non-ferromagnetic layer is Ta, and the thickness is 10nm;
the ferromagnetic layer is Co 20 Fe 60 B 20 Thickness is 1.2nm;
the material of the first metal insertion layer (ultrathin metal insertion layer) is Mg, and the thickness is 0.6nm;
the material of the oxide layer was MgO, with a thickness of 3.5nm.
In the embodiment, a magnetron sputtering technology is combined with a material characterization means to optimize growth conditions, and a non-ferromagnetic layer, a ferromagnetic layer, an ultrathin metal insertion layer and an oxide layer are sequentially grown on a silicon oxide substrate through preparation of a high-quality film, so that perpendicular magnetic anisotropy of the film is realized at room temperature.
The multilayer film structure provided in this example was prepared by the following steps:
ultrasonic cleaning of wafer with acetone, ethanol and deionized water using magnetismDirect current sputtering deposition metal layer material and radio frequency sputtering deposition oxide layer material of the sputtering control technology; the deposition time of each layer of material was tightly calibrated to control the sputtering rate, ta, at a rate ofCo 20 Fe 60 B 20 Is +.>The rate of Mg is->The MgO rate is +.>
After sputtering is completed, standing for about one week or applying voltage between the oxide layer and the ferromagnetic layer, and transferring oxygen atoms/oxygen ions to an interface between the non-ferromagnetic layer and the ferromagnetic layer through oxidation engineering effect to influence the track hybridization of the non-ferromagnetic layer, further influence the interface between the non-ferromagnetic layer and the ferromagnetic layer and further regulate and control the ratio of field-like moment/damping-like moment.
The preparation of the micron-sized Hall rod can be realized by adopting a photoetching technology, an electron beam evaporation technology, a stripping technology and the like to process the patterns of the film.
In sputter growth, co is generally difficult to avoid 20 Fe 60 B 20 Is oxidized mainly from high-energy oxygen ions of the MgO layer during sputtering and oxygen migration caused after annealing. Therefore, the out-of-plane spin orbit torque can be realized by utilizing the oxidation engineering effect to induce an in-plane bias field, meanwhile, the ratio of a field-like moment component to a damping-like moment component in the spin orbit torque is improved, the intrinsic field-like moment to damping-like moment ratio of the material before oxidation treatment is smaller than +3, and the ratio can be improved to about +4 through the oxidation engineering effect.
Fig. 2 is a schematic diagram showing the structure breaking symmetry of the multilayer nanofilm of example 1. In this embodiment, the ferromagnetic layer is relatively thin and has a relatively thick magnetic dead layer, so that oxygen atoms can migrate by standing for about one week; the unit cell structure of the non-ferromagnetic layer is affected by the migration of oxygen atoms to create out-of-plane spin-orbit torque polarization. The symmetry operation is broken at the non-ferromagnetic layer/highly symmetric ferromagnetic layer interface or in systems with vertical structural gradients.
Current-induced spin polarization unit vector sigma and magneto-electric tensor χ and charge flow j c Related to the following. Consider the most general form of χ as:
sigma is in its most general form:
one fairly straightforward way to study χ is through group symmetry. If a system has a set of symmetry operations { R }, then χ should be characterized as:
only χ zx Or χ zy Current-induced sigma while remaining non-zero after application of all symmetry operations { R } z Can exist. In the single unit cell section of the non-ferromagnetic layer material of the present invention, there are ubiquitous dual rotational symmetry along the vertical axis, multiple specular symmetries, which will lead to χ zx With χ zy All 0. The damage of structural symmetry can be realized by using external doping, so that the χ at the interface of the nonferromagnetic layer/the high-symmetry ferromagnetic layer zx With χ zy Can take a non-zero value and ultimately produce out-of-plane spin-orbit torque polarization upon current excitation.
Fig. 3 is a schematic diagram of the multilayer nanofilm of example 1 to achieve field-free moment flipping. In this embodiment, the result obtained by the micro-magnetic simulation method is: when the similar field/similar damping ratio is larger, the external in-plane magnetic field required by spin orbit moment overturning is obviously reduced, and the similar damping moment overcomes damping to do positive work in the process of magnetic moment precession, so that magnetic moment overturning occurs. The larger field-like moment improves the working efficiency of the damping-like moment and assists the overturning. The external in-plane magnetic field and the current density required by the turnover are reduced, and the low-power-consumption turnover is realized.
Example 2
The embodiment provides a regulated multilayer nano-film structure, and the structure of the regulated multilayer nano-film structure is shown in fig. 4.
The regulating and controlling multilayer nano film structure comprises a non-ferromagnetic layer, a ferromagnetic layer, an ultrathin metal insertion layer, an oxide layer and an electrode film which are arranged on a silicon substrate from bottom to top in growth sequence, wherein a voltage source is arranged between the electrode film and the ferromagnetic layer; wherein:
the material of the non-ferromagnetic layer is Ta, and the thickness is 10nm;
the ferromagnetic layer is Co 20 Fe 60 B 20 Thickness is 1.2nm;
the material of the ultrathin metal insertion layer is Mg, and the thickness is 0.6nm;
the material of the oxide layer was MgO, with a thickness of 3.5nm.
In the embodiment, a magnetron sputtering technology is combined with a material characterization means to optimize growth conditions, and a nonferromagnetic layer, a ferromagnetic layer, an ultrathin metal insertion layer, an oxide layer and an electrode film layer are sequentially grown on a silicon oxide substrate through preparation of a high-quality film. The film is subjected to pattern processing by adopting a photoetching technology, a dry etching technology, an electron beam evaporation technology and a stripping technology, so that the preparation of the micron-sized Hall rod is realized.
In sputter growth, co is generally difficult to avoid 20 Fe 60 B 20 Oxidized mainly from high-energy oxygen ions of the MgO layer during sputtering and oxygen migration caused after annealing;
after sputtering is completed, a voltage of more than +5V is applied by a voltage source and is maintained for 60s, oxygen atoms/oxygen ions migrate to the interface between the non-ferromagnetic layer and the ferromagnetic layer through oxidation engineering effect, so that the track hybridization of the non-ferromagnetic layer is influenced, the interface between the non-ferromagnetic layer and the ferromagnetic layer is further influenced, and the ratio of field-like moment/damping-like moment is regulated and controlled.
The voltage source is used for regulating and controlling the migration of oxygen ions: when oxygen ions exist in the ferromagnetic layer, the oxygen ions can change saturation magnetization intensity, anisotropic energy and the like, so that the track hybridization on the interface between the non-ferromagnetic layer and the ferromagnetic layer is further changed, and the interface effect of the multilayer nano film is further regulated; when oxygen ions exist in the non-ferromagnetic layer, the oxygen ions break the structural symmetry of the non-ferromagnetic layer, so that the polarization direction of out-of-plane spin-orbit moment is regulated and controlled, and meanwhile, the ratio of a quasi-field to quasi-damping is changed, so that the low-power consumption non-magnetic spin-orbit moment overturning is realized.
Example 3
This embodiment provides a multilayer film structure, the structure of which is shown in fig. 1. The multilayer film structure comprises a non-ferromagnetic layer, a ferromagnetic layer, an ultrathin metal insertion layer and an oxide layer which are sequentially arranged; wherein:
the material of the non-ferromagnetic layer is Pt, and the thickness is 2nm;
the ferromagnetic layer is Co and has a thickness of 0.8nm;
the material of the first metal insertion layer (ultrathin metal insertion layer) is Mg, and the thickness is 0.2nm;
the material of the oxide layer is MgO, and the thickness is 2.5nm;
after sputtering of each layer is completed, standing is performed for about one week, or voltage is applied between the oxide layer and the ferromagnetic layer (for example, voltage of more than +5V is applied and maintained for 60 s), oxygen atoms/oxygen ions migrate to the interface between the non-ferromagnetic layer and the ferromagnetic layer through oxidation engineering effect, so that the track hybridization of the non-ferromagnetic layer is influenced, the interface between the non-ferromagnetic layer and the ferromagnetic layer is further influenced, and the ratio of field-like moment/damping-like moment is regulated.
Example 4
The embodiment provides a regulated multilayer nano-film structure, and the structure of the regulated multilayer nano-film structure is shown in fig. 4.
The regulating and controlling multilayer nano film structure comprises a non-ferromagnetic layer, a ferromagnetic layer, an ultrathin metal insertion layer, an oxide layer and an electrode film which are arranged on a silicon substrate from bottom to top in growth sequence, wherein a voltage source is arranged between the electrode film and the ferromagnetic layer; wherein:
the material of the non-ferromagnetic layer is Bi 2 Te 3 The thickness is 8nm;
the ferromagnetic layer is made of Fe 3 GeTe 2 The thickness is 4nm;
the material of the ultrathin metal insertion layer is Mg, and the thickness is 0.2nm;
the material of the oxide layer is MgO, and the thickness is 2.5nm;
after the sputtering of each layer is completed, a voltage is applied between the oxide layer and the ferromagnetic layer through a voltage source (for example, a voltage of more than +5V is applied and maintained for 60 seconds), oxygen atoms/oxygen ions migrate to the interface between the non-ferromagnetic layer and the ferromagnetic layer through an oxidation engineering effect, the track hybridization of the non-ferromagnetic layer is affected, the interface between the non-ferromagnetic layer and the ferromagnetic layer is further affected, and the ratio of the field-like moment/damping-like moment is regulated.
Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present invention, and are not limiting; although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present invention.
Claims (10)
1. A method for realizing spin orbit moment without external magnetic field, wherein the method is to change the ratio of field-like moment to damping-like moment in spin orbit moment by utilizing oxidation engineering effect on a multilayer film structure, wherein:
the multilayer film structure comprises an oxide layer, a ferromagnetic layer and a nonferromagnetic layer which are sequentially arranged;
the ratio of the field-like moment to the damping-like moment in the spin orbit moment is changed by using oxygen atoms and/or oxygen ions to influence the nonferromagnetic layer, and the method specifically comprises the following steps of: after the multilayer film structure is prepared, standing is carried out, so that oxygen atoms and/or oxygen ions migrate to an interface between the nonferromagnetic layer and the ferromagnetic layer, or voltage is applied between the oxide layer and the ferromagnetic layer, so that the oxygen atoms and/or the oxygen ions migrate to the interface between the nonferromagnetic layer and the ferromagnetic layer;
preferably, the migration of oxygen atoms and/or oxygen ions includes one or a combination of two or more of migration of high-energy oxygen ions of the oxide layer during sputtering, migration of oxygen atoms in the oxide layer, and oxygen migration caused after annealing;
preferably, the ratio of the field-like moment to the damping-like moment in the spin orbit moment is-8 to +8, more preferably +3 to +5;
preferably, the applied voltage is from-20V to 20V; the time for applying the voltage is 5s-60s.
2. The method of claim 1, wherein the thickness of the non-ferromagnetic layer is 1-10nm, preferably 2-10nm, more preferably 5-10nm;
preferably, the material of the non-ferromagnetic layer is selected from one or a combination of more than two of heavy metal materials or topological insulating materials;
preferably, the heavy metal material is selected from one or more than two of Ta, pt, W, ir and Mo; more preferably Ta;
preferably, the topologically insulating material is selected from Bi 2 Se 3 ，Bi 2 Te 3 ，Bi x Sb 1-x ，Sb 2 Te 3 And (Bi) x Sb 1-x ) 2 Te 3 One or a combination of two or more of them;
more preferably, the Bi x Sb 1-x X in (2) is 0.9;
more preferably, the (Bi x Sb 1-x ) 2 Te 3 The value of x in (2) ranges from 0 to 1;
more preferably, the non-ferromagnetic layer material is attached over the substrate material.
3. A method according to claim 1 or 2, wherein the ferromagnetic layer has a thickness of 0.2-2nm, preferably 0.2-1.3nm, more preferably 1-1.3nm;
preferably, the ferromagnetic layer is made of one or more materials selected from CoFeB, feB, coFe;
preferably, the CoFeB comprises Co 20 Fe 60 B 20 ，Co 40 Fe 40 B 20 Or Co 60 Fe 20 B 20 The method comprises the steps of carrying out a first treatment on the surface of the More preferably Co 20 Fe 60 B 20 ；
Preferably, the FeB comprises Fe 80 B 20 ；
Preferably, the CoFe comprises Co 50 Fe 50 ，Co 20 Fe 80 Or Co 80 Fe 20 。
4. A method according to any one of claims 1-3, wherein the oxide layer has a thickness of 0.01-3.5nm, preferably 1-2.5nm, more preferably 2-2.5nm;
preferably, the material of the oxide layer is selected from MgO, al 2 O 3 ，MgAl 2 O 4 One or a combination of two or more of them; mgO is more preferable.
5. The method of any of claims 1-4, wherein an ultra-thin metal insertion layer is disposed between the ferromagnetic layer and the oxide layer of the multilayer film structure;
preferably, the thickness of the ultra-thin metal insertion layer is 0.01 to 0.8nm, more preferably 0.2 to 0.8nm, still more preferably 0.2 to 0.6nm;
preferably, the material of the ultrathin metal insertion layer is selected from one or more than two of Mg, ti, al and Hf; mg is more preferred.
6. The method of any one of claims 1-5, wherein the resting time is 7 days to 30 days.
7. Use of the method of any one of claims 1-6 for the preparation of an electronic device having a multilayer film structure;
preferably, the electronic device is a magnetic random access memory device.
8. A multilayer film structure comprising a non-ferromagnetic layer, a ferromagnetic layer, and an oxide layer disposed in that order; preferably, an ultrathin metal insertion layer is arranged between the ferromagnetic layer and the oxide layer;
the multilayer film structure is prepared by the method of any one of claims 1-6.
9. A Hall rod comprises a substrate, a non-ferromagnetic layer, a ferromagnetic layer, an oxide layer and an electrode film layer which are sequentially arranged; preferably, an ultrathin metal insertion layer is arranged between the ferromagnetic layer and the oxide layer;
the hall bar is prepared by the method of any one of claims 1-6.
10. A magnetic random access memory comprising the multilayer film structure of claim 8 or the hall bar of claim 9.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210936818.9A CN117577445A (en) | 2022-08-05 | 2022-08-05 | Method for realizing spin orbit moment without external magnetic field, multilayer film structure, hall rod and magnetic random access memory |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210936818.9A CN117577445A (en) | 2022-08-05 | 2022-08-05 | Method for realizing spin orbit moment without external magnetic field, multilayer film structure, hall rod and magnetic random access memory |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN117577445A true CN117577445A (en) | 2024-02-20 |
Family
ID=89859465
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210936818.9A Pending CN117577445A (en) | 2022-08-05 | 2022-08-05 | Method for realizing spin orbit moment without external magnetic field, multilayer film structure, hall rod and magnetic random access memory |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117577445A (en) |
-
2022
- 2022-08-05 CN CN202210936818.9A patent/CN117577445A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Yang et al. | Ionic liquid gating control of RKKY interaction in FeCoB/Ru/FeCoB and (Pt/Co) 2/Ru/(Co/Pt) 2 multilayers | |
| Gushi et al. | Large current driven domain wall mobility and gate tuning of coercivity in ferrimagnetic Mn4N thin films | |
| US9343658B2 (en) | Magnetic memory bits with perpendicular magnetization switched by current-induced spin-orbit torques | |
| EP2820680B1 (en) | Engineered magnetic layer with improved perpendicular anisotropy using glassing agents for spintronic applications | |
| US8592927B2 (en) | Multilayers having reduced perpendicular demagnetizing field using moment dilution for spintronic applications | |
| Wang et al. | Voltage-induced switching in magnetic tunnel junctions with perpendicular magnetic anisotropy | |
| EP2873079B1 (en) | Engineered magnetic layer with improved perpendicular anisotropy using glassing agents for spintronic applications | |
| CN107636851B (en) | Perpendicular magnetic memory with symmetric fixed layer | |
| KR102658922B1 (en) | Semiconductor device and method of making the same | |
| US10170687B2 (en) | Spin torque majority gate device | |
| US11031544B2 (en) | Memory device with superparamagnetic layer | |
| CN110112286B (en) | Magnetic tunnel junction device for magnetic random access memory | |
| KR102384258B1 (en) | perpendicular magnetic memory with reduced switching current | |
| CN108335977A (en) | Manufacture the method and magnetic memory of magnetic knot | |
| TWI643367B (en) | Material composition for foming free layer of magnetic device, free layer and magnetic element | |
| Song et al. | Field‐free spin‐orbit torque switching of perpendicular magnetization by making full use of spin Hall effect | |
| CN117577445A (en) | Method for realizing spin orbit moment without external magnetic field, multilayer film structure, hall rod and magnetic random access memory | |
| CN113488584A (en) | FePt material-based magnetization switching device, external magnetic field-free switching method and application | |
| CN115589764A (en) | Magnetic random access memory unit and preparation method and use method thereof | |
| Zhao et al. | Controlling domain wall and field-free spin–orbit torque switching in synthetic antiferromagnets | |
| US11785859B2 (en) | Voltage-controlled magnetoresistance device comprising layered magnetic material and layered ferroelectric material | |
| Wu et al. | Electrically manipulating exchange bias and realizing multiple remanent states in platinum/cobalt/iridium manganese heterostructures | |
| CN115884602A (en) | Dual-mode voltage-regulated MRAM (magnetic random Access memory) storage unit based on ferroelectric/ferromagnetic material coupling, and regulation method and preparation method thereof | |
| CN113903855A (en) | Method for improving overturning efficiency of spin orbit torque of multilayer film structure, magnetic tunnel junction and magnetic random access memory | |
| KR101093976B1 (en) | METHOD FOR FABRICATING PERPENDICULAR MAGNETIC ANISOTROPY CoFeB FILMS AND MAGNETIC RANDOM ACCESS MEMORY FABRICATED USING THE SAME |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |