Magnetoresistive device and method thereof

Abstract

A magnetoresistive device's magnetoresistive stack or structure includes one or more electrodes or conductive lines, a magnetically fixed region, a magnetically free region disposed between the electrodes or conductive lines, and a dielectric layer disposed between the free region and the fixed region. The magnetoresistive device may also include a spin Hall (SH) material adjacent to at least a portion of the free region, and one or more intercalation layers including an antiferromagnetic material.

Description

[0001] Cross-references to related applications

[0002] This application claims priority to U.S. non-provisional application No. 16 / 750,264, filed January 23, 2020, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to magnetoresistive devices and methods for manufacturing and / or using the disclosed magnetoresistive devices.

[0004] Brief

[0005] In one or more embodiments, this disclosure relates to a magnetoresistive device having a magnetoresistive stack or structure (e.g., part of a magnetoresistive storage device and / or a magnetoresistive sensor / transducer device) and a method of manufacturing and operating said magnetoresistive device. In one embodiment, an exemplary magnetoresistive stack of this disclosure (e.g., for use in a magnetic tunnel junction (MTJ) magnetoresistive device) comprises one or more layers of magnetic or ferromagnetic material.

[0006] In summary, the magnetoresistive stack for a storage device (e.g., a magnetoresistive random access memory (MRAM)) disclosed herein includes at least one non-magnetic layer (e.g., at least one dielectric layer, or a non-magnetic but conductive layer) disposed between a "fixed" magnetic region and a "free" magnetic region, each of the "fixed" and "free" magnetic regions comprising one or more layers of ferromagnetic material. Information is stored in the magnetoresistive memory stack by switching, programming, and / or controlling the direction of the magnetization vector in the magnetic layer of the free magnetic region. The direction of the magnetization vector in the free magnetic region can be adjacent to or through the magnetoresistive memory stack by applying a write signal (e.g., one or more current pulses). Conversely, the magnetization vector in the magnetic layer of the fixed magnetic region is magnetically fixed in a predetermined direction during the application of the write signal. The magnetoresistive memory stack has a first magnetic state when the magnetization vector of the free magnetic region adjacent to the non-magnetic layer is in the same direction as the magnetization vector of the fixed magnetic region adjacent to the non-magnetic layer. Conversely, the magnetoresistive memory stack has a second magnetic state when the magnetization vector of the free magnetic region adjacent to the non-magnetic layer is in the opposite direction to the magnetization vector of the fixed magnetic region adjacent to the non-magnetic layer. The magnetoresistive memory stack has different resistances in the first and second magnetic states. For example, the resistance value of the second magnetic state may be relatively higher than that of the first magnetic state. In response to a read current applied, for example, through the magnetoresistive stack, the magnetic state of the magnetoresistive memory stack is determined or read based on the resistance value of the stack.

[0007] As magnetic memory devices (e.g., MRAM) advance to smaller process nodes to increase density, the size of individual MTJ bits must shrink laterally to accommodate tighter pitches and space between bits. However, as the size and / or aspect ratio of MTJ bits decreases, their shape magnetic anisotropy also decreases. With reduced shape anisotropy, the energy barrier of the MTJ may decrease. However, with a lower energy barrier, data retention and / or thermal stability of the MTJ bit may also decrease. Typically, the decrease in the energy barrier of the MTJ bit can be corrected by increasing the vertical anisotropy or magnetic moment of the free region by changing the composition / material / thickness of the free region. However, doing so may also increase the critical current of the MTJ bit (described in more detail below). MTJ bits with high critical currents experience a greater amount of periodic on-off and degradation during write and / or reset operations, negatively impacting the robustness of the MTJ device (i.e., MRAM).

[0008] This disclosure relates to means (e.g., means comprising a magnetoresistive structure and / or stack) and methods for writing or otherwise switching the magnetic state of a magnetoresistive memory device via STT and / or SOT switching schemes. More specifically, the following description describes embodiments of MTJ geometries that integrate SOT and / or STT switching mechanisms, individually or in combination, to provide improved switching efficiency, enabling the switching of high-energy-barrier MTJ bits without using unnecessarily high write currents. However, the scope of this disclosure is defined by the appended claims and not by any feature of the resulting means or methods. Attached Figure Description

[0009] Embodiments of this disclosure may be implemented in conjunction with aspects illustrated in the accompanying drawings. These drawings illustrate different aspects of this disclosure, and where appropriate, reference numerals indicating similar structures, components, materials, and / or elements are similarly labeled in the different drawings. It should be understood that various combinations of these structures, components, and / or elements are contemplated and are within the scope of this disclosure, in addition to those specifically shown.

[0010] For simplicity and clarity, the accompanying drawings depict the general structure and / or configuration of the various embodiments described herein. For ease of illustration, the drawings depict different layers / regions of the illustrated magnetoresistive stack as having uniform thickness and well-defined boundaries with straight edges. However, those skilled in the art will recognize that in practice, different layers typically have non-uniform thicknesses. Furthermore, at the interfaces between adjacent layers, the materials of these layers may alloy together or migrate into one or another material, making their boundaries indistinct. Descriptions and details of well-known features (e.g., interconnections, etc.) and techniques may be omitted to avoid obscuring other features. Elements in the figures are not necessarily drawn to scale. The dimensions of some features may be exaggerated relative to others to improve understanding of the exemplary embodiments. The drawings are simplifications provided to aid in illustrating the relative positioning of the various regions / layers and describing the various processing steps. Those skilled in the art will understand that these regions are not necessarily drawn to scale and should not be considered as representing proportional relationships between different regions / layers. Furthermore, while some regions / layers and features are illustrated as having straight 90-degree edges, in practice or in actual practice, these regions / layers may be more “rounded,” curved, and / or gradually sloping.

[0011] Furthermore, those skilled in the art will understand that although multiple layers with defined interfaces are shown in the figures, in some cases, with time and / or exposure to high temperatures, the material of some layers may migrate into or interact with the materials of other layers, presenting a more dispersed interface between these layers. It should be noted that, even without specific mention, aspects described in conjunction with one embodiment can be applied to other embodiments and can be used in conjunction with other embodiments.

[0012] Furthermore, numerous embodiments are described and illustrated herein. This disclosure is neither limited to any single aspect or embodiment thereof, nor to any combination and / or arrangement of such aspects and / or embodiments. Moreover, each aspect and / or embodiment of this disclosure may be used alone or in combination with one or more other aspects and / or embodiments of this disclosure. For the sake of brevity, certain arrangements and combinations are not discussed and / or described separately herein. It is important to note that embodiments or implementations described herein as “exemplary” should not be construed as being more preferred or advantageous than other embodiments or implementations, for example; rather, it is intended to reflect or indicate that the embodiments involved are “exemplary” embodiments. Furthermore, even though the accompanying drawings and this written disclosure appear to depict the magnetoresistive stacks of the disclosed magnetoresistive device in a specific construction order (e.g., from bottom to top), it should be understood that the depicted magnetoresistive stacks may have a different order (e.g., the reverse order (i.e., from top to bottom)).

[0013] Figure 1-16A schematic diagram of a region of a magnetoresistive structure utilizing an SOT and / or STT switching mechanism according to one or more embodiments of the present disclosure is shown.

[0014] Figure 17A A schematic diagram of a region of a magnetoresistive structure utilizing an SOT and / or STT switching mechanism according to one or more embodiments of the present disclosure is shown.

[0015] Figure 17B A depiction of one or more embodiments according to this disclosure is shown. Figure 17A A top view of the cross-section of the magnetoresistive structure shown;

[0016] Figure 18 A side view depicting a magnetoresistive structure during a stage of manufacturing according to one or more embodiments of the present disclosure is shown;

[0017] Figure 19 The illustration shows a side view depicting a magnetoresistive structure during a stage of manufacturing according to one or more embodiments of the present disclosure;

[0018] Figure 20 A side view depicting a magnetoresistive structure during a stage of manufacturing according to one or more embodiments of the present disclosure is shown;

[0019] Figure 21 A side view depicting a magnetoresistive structure during a stage of manufacturing according to one or more embodiments of the present disclosure is shown;

[0020] Figure 22A A side view depicting a magnetoresistive structure during a stage of manufacturing according to one or more embodiments of the present disclosure is shown;

[0021] Figure 22B It shows Figure 22A Vertical side view of the magnetoresistive structure shown;

[0022] Figure 22C It shows Figure 22A and 22B A top view of the magnetoresistive structure shown;

[0023] Figure 23 A side view depicting a magnetoresistive structure during a stage of manufacturing according to one or more embodiments of the present disclosure is shown;

[0024] Figure 24A A side view depicting a magnetoresistive structure during a stage of manufacturing according to one or more embodiments of the present disclosure is shown;

[0025] Figure 24B It shows Figure 24A Vertical side view of the magnetoresistive structure shown;

[0026] Figure 24C It shows Figure 24A and 24B A top view of the magnetoresistive structure shown;

[0027] Figure 25-27 This is a flowchart illustrating one or more exemplary processes for manufacturing a magnetoresistive structure utilizing SOT and / or STT switching mechanisms;

[0028] Figure 28 This is a schematic diagram of an exemplary magnetoresistive memory stack electrically connected to a selection device (e.g., an access transistor) in a magnetoresistive memory cell configuration.

[0029] Figure 29A and 29B This is a schematic block diagram of an integrated circuit including discrete memory devices and embedded memory devices, each memory device including an MRAM (in one embodiment, it represents one or more MRAM arrays having a plurality of magnetoresistive memory stacks according to certain embodiments of the present disclosure).

[0030] Similarly, numerous embodiments are described and illustrated herein. This disclosure is neither limited to any single aspect or embodiment thereof, nor to any combination and / or arrangement of such aspects and / or embodiments. Each aspect and / or embodiment of this disclosure may be used alone or in combination with one or more other aspects and / or embodiments of this disclosure. For the sake of brevity, many of these combinations and arrangements are not discussed separately herein. Detailed Implementation

[0031] It should be noted that all numerical values ​​disclosed herein (including all disclosed thickness values, limits, and ranges) may deviate from the disclosed values ​​by ±10% (unless a different deviation is specified). For example, the thickness of a layer disclosed as "t" units thick can vary from (t-0.1t) to (t+0.1t) units. Furthermore, all relevant terms such as "approximately," "substantially," and "approximately" are used to indicate a possible deviation of ±10% (unless otherwise stated or specified). Additionally, in the claims, for example, the values, limits, and / or ranges of the thickness and atomic composition of the described layers / regions also represent said values, limits, and / or ranges by ±10%.

[0032] It should be noted that the descriptions set forth herein are merely illustrative in nature and are not intended to limit the embodiments of the subject matter or the application and use of such embodiments. Any implementation described herein as exemplary should not be construed as preferred or advantageous to other implementations. Rather, the term "exemplary" is used in the sense of example or "illustrative," not "ideal." The terms "comprising," "including," "having," "having," and any variations thereof are used synonymously to indicate or describe non-exclusive inclusion. Thus, an apparatus or method using such terms may include not only those elements or steps but also other elements and steps not expressly listed or inherent to such apparatus and methods. Furthermore, the terms "first," "second," etc., used herein do not indicate any order, quantity, or importance but are used to distinguish one element from another. Similarly, terms of relative orientation, such as "top," "bottom," etc., are used with reference to the orientation of the structures shown in the described figures. Moreover, the terms "a" and "an" used herein do not indicate a limitation of quantity but indicate the presence of at least one of the cited items.

[0033] It should also be noted that although exemplary embodiments are described in the context of MTJ stacks / structures, the invention can also be implemented in conjunction with giant magnetoresistive (GMR) stacks / structures, wherein a conductor (e.g., a copper layer) is located between two ferromagnetic regions / layers / materials. Embodiments of this disclosure can be used in conjunction with other types of magnetoresistive stacks / structures, wherein such stacks / structures include fixed magnetic regions. For the sake of brevity, the discussions and descriptions presented in this disclosure will not be specifically repeated in the context of GMR or other magnetoresistive stacks / structures (e.g., anisotropic magnetoresistive (AMR) devices), but the discussions and figures described below should be interpreted as fully applicable to GMR and other magnetoresistive stacks / structures (e.g., AMR-type devices).

[0034] In this disclosure, the term "region" is generally used to refer to one or more layers. That is, a region (as used herein) may include a single layer of material (deposit, film, coating, etc.) or a multilayer of material stacked on top of another (i.e., a multilayer structure). Furthermore, while different regions and / or layers in the disclosed magnetoresistive devices may be referred to by specific names (e.g., bottom electrode, top electrode, fixed magnetic region, free magnetic region) in the following description, this is merely for ease of description and is not intended as a functional description or a description of the relative positions / orientations of the layers. Moreover, while the following description and figures appear to depict a particular orientation of the layers relative to each other, those skilled in the art will understand that such descriptions and depictions are merely exemplary. For example, while a free region of a magnetoresistive stack may be described as being "above" the spin Hall (SH) material, in some respects the entire depicted magnetoresistive structure may be flipped so that the free region is "below" the SH material.

[0035] In one exemplary embodiment, the magnetoresistive structure of the magnetoresistive device disclosed herein can be implemented as an STT and / or SOTMRAM element. In such embodiments, the magnetoresistive structure may include an intermediate layer disposed (e.g., sandwiched) between two ferromagnetic regions to form an MTJ device or an MTJ-type device. Of the two ferromagnetic regions disposed on either side of the intermediate layer, one ferromagnetic region may be a fixed (or pinned) magnetic region, while the other ferromagnetic region may be a free magnetic region. The term "free" is intended to refer to a ferromagnetic region having a magnetic moment that can significantly deflect or shift in response to an applied magnetic field or spin-polarized current for switching the magnetic moment vector. Accordingly, the terms "fixed" or "pinned" are used to refer to a ferromagnetic region having a magnetic moment vector that is substantially unresponsive to such an applied magnetic field or spin-polarized current. As is known in the art, the resistance of the described magnetoresistive structure can be varied based on whether the magnetization direction (e.g., direction of the magnetic moment) of the free region adjacent to the nonmagnetic layer (e.g., tunneling barrier) is arranged parallel or antiparallel to the magnetization direction (e.g., direction of the magnetic moment) of the fixed region adjacent to the nonmagnetic layer. Typically, if the two regions have the same magnetization arrangement, the resulting relatively lower resistance is considered a digital "0", while if the arrangement is antiparallel, the resulting relatively higher resistance is considered a digital "1". A memory device (e.g., MRAM) may include multiple magnetoresistive structures / stacks, which may be referred to as memory cells or elements, arranged in an array of columns and rows. By measuring the current through each cell, the resistance of each cell can be read, thereby allowing the data stored in the memory array to be read.

[0036] In some embodiments, the free magnetic region and the fixed magnetic region may each comprise multiple layers of magnetic or ferromagnetic materials, such as materials comprising one or more of the ferromagnetic elements nickel (Ni), iron (Fe), and cobalt (Co), alloys or engineered materials having one or more of the elements palladium (Pd), platinum (Pt), magnesium (Mg), manganese (Mn), chromium (Cr), and boron (B), and one or more synthetic antiferromagnetic structures (SAF) or synthetic ferromagnetic structures (SyF). One or more of the magnetic material layers may further comprise one or more layers of non-magnetic materials (e.g., ruthenium (Ru), copper (Cu), aluminum (Al), tantalum (Ta), titanium (Ti), niobium (Nb), vanadium (V), zirconium (Zr), iridium (Ir), and one or more alloys thereof, and in some embodiments, tungsten (W) and molybdenum (Mo). An intermediate layer (e.g., a dielectric layer) may be, for example, one or more layers of alumina and / or magnesium oxide.

[0037] In magnetoresistive devices utilizing the SOT switching mechanism, the magnetization of the free region of the magnetoresistive stack can be switched by driving a current pulse through the SH material adjacent to (e.g., in contact with or near) the free region. Examples of SH materials include, but are not limited to: platinum (Pt), β-tungsten (β-W), tantalum (Ta), palladium (Pd), hafnium (Hf), gold (Au), alloys containing gold (e.g., AuPt, AuCu, AuW), alloys containing bismuth (Bi) and selenium (Se) (e.g., Bi2Se3 or (BiSe)2Te3), alloys containing copper (Cu) and one or more of platinum (Pt), bismuth (Bi), iridium (Ir), or lead (Pb) (e.g., CuPt alloy, CuBi alloy, CuIr alloy, CuPb alloy), alloys containing silver (Ag) and bismuth (Bi) (e.g., AgBi alloy), alloys containing manganese (Mn) and one or more of platinum (Pt), iridium (Ir), palladium (Pd), or iron (Fe) (e.g., PtMn alloy, IrMn alloy, PdMn alloy, FeMn alloy), or combinations thereof.

[0038] The average current required to change the magnetic state of a free region is called the critical current (Ic). The critical current represents the current required to "write" data into a magnetoresistive memory cell. Lowering the critical current is desirable to allow for smaller access transistors per cell and to enable the production of higher-density, lower-cost memories, among other things. A lower critical current can also lead to longer lifespan and / or durability of magnetoresistive memory cells.

[0039] The embodiments described herein utilize a substance known as a spin current to switch or facilitate switching the magnetic state of a free region in an MTJ or similar device. A current flowing through the SH material adjacent to (and / or in contact with) the free region results in a spin torque acting on the free region, due to the injection of a spin current into the free region by spin-dependent scattering of electrons from the SH material. The direction of the applied spin current is determined by the polarity of the current through the SH material and the polarity of the SH material itself. The spin current is injected into the free region in a direction perpendicular to the boundary (or interface) where the free region and the SH material intersect and orthogonal to the direction of current flow. The spin torque applied to the free region by the spin current affects the magnetic state of the free region in a manner similar to the spin-polarized tunneling current flowing through an MTJ in a conventional STT magnetic tunnel junction. Since the function of the STT magnetic tunnel junction is well known in the art, it will not be described further here.

[0040] Similar to the write current in conventional STT MTJ devices, in devices using the SOT switching mechanism, the direction of the torque applied by the spin current depends on the current direction in the SH material. In other words, the current direction in the adjacent free region within the SH material determines the direction of the torque applied to the free region. Therefore, the free region can switch between two stable states based on the torque applied by the current flowing in one or the other direction in the adjacent SH material. In some embodiments, the free region can switch between two stable magnetic states based on the torque applied by the STT current flowing through the MTJ in either direction. The magnetic state of the free region can also be switched by the torque caused by the STT current applied through the MTJ bit and the spin torque generated by the spin current injected from one or more SH materials by the applied current flowing through one or more SH materials.

[0041] In some embodiments, the torque applied solely by the spin current (i.e., the SOT current) is used to switch the free region to a specific magnetic state, while in other embodiments, the spin current acts as an "auxiliary" force to reduce the amplitude of the STT write current required to switch the magnetic state of the free region, wherein the STT write current flows through the entire MTJ stack to generate a spin-polarized tunneling current between the free and stationary regions. Reading the data stored in the MTJ stack is performed as in a conventional STT MTJ device. For example, a read current smaller than the critical current of the MTJ stack is applied to the MTJ stack to sense the resistance of the MTJ stack. As those skilled in the art will recognize, many techniques are available for detecting or sensing the resistance of the MTJ stack. In some embodiments, the resistance sensed based on the read current can be compared to a reference resistance to determine the state of the free region. In some embodiments, a self-reference read operation is performed, wherein the resistance through the MTJ is sensed, then the MTJ is written to (or reset) such that the free region is in a known state, and then the resistance is sensed again and compared to the initially sensed resistance. The initial state of the free region can then be determined based on whether the resistance sense has changed based on the write or reset operation. In some other embodiments, a midpoint reference read operation can be performed.

[0042] For the sake of brevity, conventional techniques related to semiconductor processes may not be described in detail here. Exemplary embodiments can be fabricated using known photolithography processes. The fabrication of integrated circuits, microelectronic devices, microelectromechanical devices, microfluidic devices, and photonic devices involves the creation of several layers or regions of material (e.g., including one or more layers) that interact in some way. One or more of these regions can be patterned such that the various regions of the layer have different electrical or other properties, and they can be interconnected within the region or with other regions to form electrical components and circuits. These regions can be created by selectively introducing or removing various materials. The patterns defining such regions are typically created by photolithography processes. For example, a photoresist layer is applied to a layer covering a wafer substrate. A photomask (containing transparent and opaque areas) is used to selectively expose the photoresist by a form of radiation (e.g., ultraviolet light, electrons, or X-rays). The photoresist exposed to or not exposed to radiation is removed by the application of a developer. Etching can then be used / applied, thereby patterning the layer (or material) not protected by the remaining photoresist. Alternatively, an additive process can be used, in which a photoresist is used as a template to build the structure.

[0043] As described above, in one aspect, the described embodiments relate to a method of manufacturing a magnetoresistive stack having one or more conductive electrodes, vias, or conductors on either side of a magnetic material stack. As described in further detail below, the magnetic material stack may include a number of different material regions, some of which include magnetic materials while others do not. In one embodiment, the manufacturing method includes sequentially depositing, growing, sputtering, evaporating, and / or providing (collectively referred to herein as “deposit”) regions that form the magnetoresistive stack after further processing (e.g., etching).

[0044] In some embodiments, the disclosed magnetoresistive stack may be formed between a top electrode / via / line and a bottom electrode / via / line, and it allows access to the stack by allowing circuitry (e.g., electrical connections) to the magnetoresistive device and other components. Between the electrodes / via / lines are multiple regions, including at least one fixed magnetic region (hereinafter referred to as a fixed region) and at least one free magnetic region (hereinafter referred to as a free region), and one or more intermediate layers (e.g., dielectric layers) that form a tunnel barrier between the fixed and free regions. Each of the fixed and free regions may include, among other things, multiple ferromagnetic layers. In some embodiments, the fixed region (e.g., fixed region 160 discussed below) may include a synthetic antiferromagnetic material (SAF). In some embodiments, the top electrode (and / or) and bottom electrode may be removed, and bit lines and / or SH material may be formed on top of the stack. Furthermore, each magnetoresistive stack may be positioned adjacent to the SH material. The SH material may be configured to carry current and impart spin current on the free regions during write and reset operations. In one or more embodiments, one or more electrodes of the magnetoresistive stack may include SH material. In other embodiments, a magnetoresistive stack may be formed between the top and bottom electrodes and adjacent to the SH material, which is independently connected to the current source. In such embodiments, the magnetoresistive structure or device may be referred to as a three-terminal magnetoresistive device.

[0045] According to one or more embodiments, the magnetoresistive structure may include a reference layer, a transition layer, and / or a cap region. For example, the transition layer may facilitate, enhance, or otherwise assist in the formation of a reference layer over an intermediate layer (e.g., a dielectric layer) without adversely affecting the properties of the reference layer or the intermediate layer. The transition layer may include a nonferromagnetic transition metal, such as tantalum (Ta), titanium (Ti), tungsten (W), molybdenum (Mo), or combinations and alloys thereof.

[0046] The reference layer may comprise one or more layers of material that facilitate and enhance the growth of one or more overlying regions (e.g., including the anchoring region of the SAF) during the fabrication of the magnetoresistive structure 100. The reference layer may comprise, for example, cobalt (Co), iron (Fe), and boron (B), such as a cobalt-iron-boron alloy (CoFeB), a cobalt-iron-boron-tantalum alloy (CoFeBTa), a cobalt-iron-tantalum alloy (CoFeTa), or a combination thereof. In some embodiments, the reference layer may comprise one or more alloys comprising iron (Fe), cobalt (Co), or nickel (Ni), and other elements with relatively high electronegativity (e.g., elements with electronegativity greater than that of iron (Fe)). For example, the reference layer may include one or more alloys, such as an alloy having the formula XY, where X is selected from the list including: cobalt (Co), iron (Fe), nickel (Ni), cobalt-iron (CoFe), iron-nickel (FeNi), and cobalt-nickel (CoNi), and Y is selected from the list including: silicon (Si), copper (Cu), rhenium (Re), tin (Sn), boron (B), molybdenum (Mo), ruthenium (Ru), palladium (Pd), osmium (Os), iridium (Ir), rhodium (Rh), platinum (Pt), tungsten (W), and carbon (C). The alloy contains one or more elements whose electronegativity is greater than that of iron (Fe) (e.g., silicon (Si), copper (Cu), rhenium (Re), tin (Sn), boron (B), molybdenum (Mo), ruthenium (Ru), palladium (Pd), osmium (Os), iridium (Ir), rhodium (Rh), platinum (Pt), tungsten (W), and carbon (C)).

[0047] Now for reference Figure 1-16 The relative positions and orientations of various magnetoresistive structures (e.g., free regions, intermediate layers, fixed regions, one or more SH materials and / or one or more other layers or regions) are shown. Figure 1-16 The simplified illustrations in the diagrams do not necessarily show all regions and layers of the exemplary magnetoresistive structure, but are intended to illustrate the relative positions and locations of several exemplary regions. Furthermore, although... Figure 1-16 The area depicted is rectangular, but this is only for simplicity and clarity. The magnetoresistive structure described herein can have rectangular, trapezoidal, pyramidal, cylindrical, or other shapes.

[0048] Still referencing Figure 1-16 The magnetoresistive structure 100 may include one or more regions or layers between the lines, strips, or regions of the SH material 110 and the top electrode 180. For example, as Figure 1As shown, the free region 120 can be disposed on and in contact with the SH material 110. The intermediate layer 130 can be disposed on and in contact with the free region 120. The fixed region 160 can be disposed on the other side of the intermediate layer 130, away from the free region 120. In some embodiments, the fixed region 160 can be disposed on and in contact with the intermediate layer 130. The magnetoresistive structure 100 may include one or more additional regions or layers, such as a cap region 170. The cap region 170 can be disposed above and in contact with the fixed region 160. The top electrode 180 can be disposed above the fixed region 160, for example, above and in contact with the cap region 170.

[0049] Refer again Figure 1-16 For read operations, current can flow from the SH material 110 through the magnetoresistive structure 100 to the top electrode 180. For write and / or reset operations, current can flow along the SH material 110, transferring spin current to the free region 120. Additionally, write current can also flow from the SH material 110 through the magnetoresistive structure 100 to the top electrode 180 to help switch the magnetic state of the free region 120.

[0050] According to one or more embodiments, the magnetoresistive structure 100 may include one or more intercalation layers adjacent to the cap region 170 and / or the transition layer 150. Each of the one or more intercalation layers may include one or more antiferromagnetic (AFM) material layers, such as platinum-manganese (PtMn) alloys, iridium-manganese (IrMn) alloys, iron-manganese (FeMn) alloys, chromium (Cr), and / or combinations thereof. In embodiments where the magnetoresistive structure 100 includes more than one intercalation layer, the composition of one intercalation layer may be the same as that of another intercalation layer, and / or the composition of one intercalation layer may be different from that of at least one other intercalation layer.

[0051] refer to Figure 2-5 The magnetoresistive structure 100 may include an insertion layer 201 disposed between the reference layer 140 and the top electrode 180. For example, the reference layer 140... Figure 2 The magnetoresistive structure 100 may include an insertion layer 201 disposed between the cap region 170 and the top electrode 180. In some embodiments, such as... Figure 3 In the illustrated embodiment, the magnetoresistive structure 100 may include an insertion layer 201 disposed between the fixed region 160 and the cap region 170. (See reference...) Figure 4 The magnetoresistive structure 100 may include an insertion layer 201 disposed between the transition layer 150 and the fixed region 160. Alternatively, the magnetoresistive structure 100 may also include an insertion layer 201 disposed between the reference layer 140 and the transition layer 150, such as... Figure 5 As shown.

[0052] The insertion layer 201 may have a thickness of less than or equal to about 2 nanometers (nm), such as less than or equal to about 1.5 nm, less than or equal to about 1 nm, about 1 nm to about 2 nm, about 1 nm to about 1.5 nm, about 0.5 nm to about 1.5 nm, about 0.5 nm to about 1.0 nm, about 0.7 nm, about 0.5 nm, or any other suitable thickness that will not adversely affect the bidirectional transport of current from the SH material 110 to the top electrode 180.

[0053] refer to Figure 6-11 The magnetoresistive structure 100 may include a first insertion layer 201 and a second insertion layer 202. As described above, the terms "first," "second," etc., do not indicate any order, quantity, or importance, but are used to distinguish one element from another. The first insertion layer 201 may have the same composition as the second insertion layer 202, or the insertion layers 201 and 202 may have different compositions. As described above, the second insertion layer 202 may have a similar thickness to the first insertion layer 201. In some embodiments, the thickness of the second insertion layer 202 may be less than the thickness of the first insertion layer 201. In other embodiments, the thickness of the second insertion layer 202 may be greater than the thickness of the first insertion layer 201.

[0054] For example, refer to Figure 6 The magnetoresistive structure 100 may include a first insertion layer 201 disposed between the fixed region 160 and the cap region 170, and a second insertion layer 202 disposed between the cap region 170 and the top electrode 180. In some embodiments, for example Figure 7 In the illustrated embodiment, the magnetoresistive structure 100 may include a first insertion layer 201 disposed between the transition layer 150 and the fixed region 160, and a second insertion layer 202 disposed between the cap region 170 and the top electrode 180. (See reference...) Figure 8 The magnetoresistive structure 100 may include a first insertion layer 201 disposed between a reference layer 140 and a transition layer 150, and a second insertion layer 202 disposed between a cap region 170 and a top electrode 180. In some embodiments, the magnetoresistive structure 100 may include: a first insertion layer 201 disposed between the transition layer 150 and a fixed region 160; and a second insertion layer 202 disposed between the fixed region 160 and the cap region 170, such as... Figure 9 As shown. Reference Figure 10The magnetoresistive structure 100 may include a first insertion layer 201 disposed between the reference layer 140 and the transition layer 150, and a second insertion layer 202 disposed between the fixed region 160 and the cap region 170. Alternatively, the magnetoresistive structure 100 may include: a first insertion layer 201 disposed between the reference layer 140 and the transition layer 150; and a second insertion layer 202 disposed between the transition layer 150 and the fixed region 160, such as... Figure 11 As shown.

[0055] refer to Figure 12-15 The magnetoresistive structure 100 may include a first insertion layer 201, a second insertion layer 202, and a third insertion layer 203. The first insertion layer 201 may have the same composition as the second insertion layer 202 and the third insertion layer 203, or one or more insertion layers 201, 202, and 203 may have a different composition than at least one other insertion layer 201, 202, and 203. The third insertion layer 203 may have a thickness similar to that of the first insertion layer 201 or the second insertion layer 202, as described above. In some embodiments, the thickness of the third insertion layer 203 may be less than the thickness of the first insertion layer 201 and / or the second insertion layer 202. Alternatively or additionally, the thickness of the third insertion layer 203 may be greater than the thickness of the first insertion layer 201 and / or the second insertion layer 202.

[0056] For example, refer to Figure 12 The magnetoresistive structure 100 may include a first insertion layer 201 disposed between the transition layer 150 and the fixed region 160, a second insertion layer 202 disposed between the fixed region 160 and the cap region 170, and a third insertion layer 203 disposed between the cap region 170 and the top electrode 180. In another example, such as Figure 13 As shown, the magnetoresistive structure 100 may include a first insertion layer 201 disposed between the reference layer 140 and the transition layer 150, a second insertion layer 202 disposed between the transition layer 150 and the fixed region 160, and a third insertion layer 203 disposed between the cap region 170 and the top electrode 180. (Refer to...) Figure 14 In some embodiments, the magnetoresistive structure 100 may include a first insertion layer 201 disposed between the reference layer 140 and the transition layer 150, a second insertion layer 202 disposed between the fixed region 160 and the cap region 170, and a third insertion layer 203 disposed between the cap region 170 and the top electrode 180. In some examples, the magnetoresistive structure 100 may include a first insertion layer 201 disposed between the reference layer 140 and the transition layer 150, a second insertion layer 202 disposed between the transition layer 150 and the fixed region 160, and a third insertion layer 203 disposed between the fixed region 160 and the cap region 170, such as... Figure 15 As shown.

[0057] refer to Figure 16 The magnetoresistive structure 100 may include four insertion layers (e.g., a first insertion layer 201, a second insertion layer 202, a third insertion layer 203, and a fourth insertion layer 204). In some embodiments, the fourth insertion layer 204 may have the same composition as the first insertion layer 201, the second insertion layer 202, and / or the third insertion layer 203. Alternatively or additionally, one or more insertion layers 201, 202, 203, 204 may have a different composition than at least one of the other insertion layers 201, 202, 203, 204. As described above, the fourth insertion layer 204 may have a thickness similar to that of the first insertion layer 201, the second insertion layer 202, or the third insertion layer 203. In some embodiments, the thickness of the fourth insertion layer 204 may be less than the thickness of the first insertion layer 201, the second insertion layer 202, and / or the third insertion layer 203. Alternatively or additionally, the thickness of the fourth insertion layer 204 may be greater than the thickness of the first insertion layer 201, the second insertion layer 202, and / or the third insertion layer 203.

[0058] Still referencing Figure 16 The magnetoresistive structure 100 may include a first insertion layer 201 disposed between the reference layer 140 and the transition layer 150, a second insertion layer 202 disposed between the transition layer 150 and the fixed region 160, a third insertion layer 203 disposed between the fixed region 160 and the cap region 170, and a fourth insertion layer 204 disposed between the cap region 170 and the top electrode 180.

[0059] Without being theoretically limited, the inclusion of one or more insert layers 201, 202, 203, 204 can induce a local magnetic field. For example, after forming the magnetoresistive structure 100, one or more subsequent processing steps (e.g., annealing) can be performed to induce magnetic moments in one or more insert layers 201, 202, 203, 204, thereby generating a local magnetic field. The induced local magnetic field can promote, improve, and / or maintain the transfer of spin current from the SH material 110 to the free region 120.

[0060] For example, refer to Figure 17AThe magnetoresistive structure 100 may include an insert layer 201. The magnetic moment of the insert layer 201 (indicated by arrow 301) can induce a local stray magnetic field 304. The local stray magnetic field 304 may have an amplitude of approximately 10 Oe to approximately 600 Oe. When a current (indicated by arrow 302) passes through the SH material 110, a spin current (indicated by arrow 303) is transferred from the SH material 110 to the free region 120. The induced local stray magnetic field 304 can improve the transfer of the spin current 303 from the SH material 110 to the free region 120 if the magnetic moment of one or more insert layers (e.g., insert layer 201) is parallel or antiparallel to the current 302 passing through the SH material 110.

[0061] Figure 17B The section cut along line 17B-17B is shown. Figure 17A The cross-section of the magnetoresistive structure 100 is shown. Figure 17B As shown, one or more insert layers (e.g., insert layer 201) may be oval, elongated, elliptical, or other non-rectangular shapes. One or more other layers and / or regions of the magnetoresistive structure 100 (e.g., free region 120, intermediate layer 130, reference layer 140, transition layer 150, fixed region 160, cap region 170) may be oval, elongated, elliptical, or other non-rectangular shapes. The magnetoresistive structure 100, including one or more layers and / or regions with non-rectangular shapes, may have shape anisotropy, which contributes to the magnetic moment of one or more magnetic or antiferromagnetic layers of the magnetoresistive structure 100.

[0062] After forming one or more layers and / or regions of the magnetoresistive structure 100, further processing steps may be performed to ensure that the magnetoresistive device structure has the desired magnetic properties. For example, further processing steps may include an annealing step to fix the magnetism of one or more insert layers 201, 202, 203, 204 and / or one or more magnetic layers (e.g., the magnetic layer of the fixing region 160). During annealing, an external magnetic field may be applied. The amplitude and / or direction of the local stray magnetic field 304 induced by one or more insert layers 201, 202, 203, 204 may depend at least in part on the angle of the magnetic field applied during annealing. During annealing, a magnetic field (e.g., the direction in which current travels through the SH material 110) may be applied to the lines of the SH material 110 in the xy plane with an incident direction of approximately 35° to approximately 55° (e.g., approximately 40° to 50°, or approximately 45°). Other suitable incident angles can be used so that the resulting insert layers 201, 202, 203, 204 have magnetic moments that are parallel or antiparallel to the direction in which the current flows through the SH material 110.

[0063] As previously described, one or more devices or systems may include a series of magnetoresistive structures 100 positioned along a linear SH material 110. The layers and regions of each magnetoresistive structure 100 above the connected SH material 110 may be referred to as a stack 200. For example, refer to... Figure 18 The magnetoresistive structure 100 shown, with stack 200, includes a free region 120, an intermediate layer 130, a reference layer 140, a transition layer 150, a fixed region 160, a cap region 170, and a top electrode 180. In other embodiments, stack 200 may include one or more insert layers 201, 202, 203, 204. Segments of SH material 110 may be connected to a series of stacks 200 arranged in lines or other arrays.

[0064] In the above method, an external magnetic field is required during annealing to disrupt the symmetry of the magnetoresistive structure 100 and induce magnetic moments in one or more layers and / or regions of the stack 200. Alternatively or additionally, one or more layers and / or regions of the magnetoresistive structure 100 can be etched in a certain way to create an asymmetric magnetoresistive structure 100, imparting the desired magnetism to one or more layers and / or regions of the stack 200. Figure 18-24C In the diagram, the stack 200 shown is similar to Figure 1 The stack 100 is shown. However, this is for illustrative purposes only, and the embodiment method can be used with any stack 200 or magnetoresistive structure 100 described herein.

[0065] refer to Figure 18-24C Similar to Figure 17A and 17B Each magnetoresistive structure 100 is drawn such that the SH material 110 is located in the xy plane and each layer and / or region of each stack 200 is located in a generally parallel xy plane shifted along the z-axis. Figure 18-24C The orientation of each region, layer, and structure shown is for clarity only. Other configurations, placements, and orientations of layers and / or regions are also conceived.

[0066] Now refer to Figure 18-24C Exemplary methods for fabricating magnetoresistive stacks with SOT switching (e.g., magnetoresistive stacks including one of the geometric features discussed above) are discussed. As previously mentioned, this document may not specifically describe common, conventional techniques associated with semiconductor fabrication. Instead, the description herein aims to highlight some aspects of the exemplary methods for fabricating the magnetoresistive structures described herein.

[0067] Figure 18 A magnetoresistive structure in the manufacturing process according to one or more embodiments of the present disclosure is shown. For example, in at least one embodiment, Figure 18The magnetoresistive structure is shown after the formation of SH material 110, free region 120, intermediate layer 130, reference layer 140, transition layer 150, fixed region 160, cap region 170, and top electrode 180. As described above, each layer or region can be located in the xy plane and shifted along the z-axis from each adjacent layer or region.

[0068] In some embodiments, after the SH material 110, free region 120, intermediate layer 130, reference layer 140, transition layer 150, fixed region 160, cap region 170, and top electrode 180 have been formed, at least a portion of the top electrode 180, cap region 170, fixed region 160, transition layer 150, reference layer 140, and / or intermediate layer 130 can be removed (e.g., etched). For example, refer to the figure. Figure 19 After at least a portion of the top electrode 180, cap region 170, fixed region 160, transition layer 150, reference layer 140, and / or intermediate layer 130 is removed, the diameter (e.g., width along the x and / or y axes) of the remaining portions of the reference layer 140, transition layer 150, fixed region 160, cap region 170, and top electrode 180 may be smaller than the diameter of the free region 120. In some embodiments, portions of the reference layer 140 are removed up to the edge of the intermediate layer 130. In other embodiments, these portions of the reference layer 140 may be “over-etched.” In other words, a portion of the intermediate layer 130 may be removed together with said portions of the top electrode 180, cap region 170, fixed region 160, transition layer 150, reference layer 140, and / or intermediate layer 130.

[0069] In some embodiments, after at least a portion of the top electrode 180, cap region 170, fixing region 160, transition layer 150, reference layer 140 and / or intermediate layer 130 is removed, one or more oxides (e.g., auxiliary oxides, silicon dioxide, etc.) or nitrides (e.g., Si) are applied. x N y It can be applied to the stack (e.g., etched magnetoresistive stack) by means of, for example, physical vapor deposition (PVD), chemical vapor deposition (CVD), other thin film manufacturing processes and / or other techniques known in the art. Figure 20 An etched magnetoresistive structure (i.e., an oxide-coated magnetoresistive stack) coated with an auxiliary oxide is shown according to one or more embodiments.

[0070] Still referencing Figure 20In one or more embodiments, an oxide region 190 is formed over the intermediate layer 130, reference layer 140, transition layer 150, fixing region 160, cap region 170, and / or top electrode 180. As used herein, oxide region 190 may refer to a region comprising an oxide (e.g., auxiliary oxide, silicon dioxide, etc.) and / or a nitride (e.g., Si). x N y In some embodiments, the oxide-coated magnetoresistive stack may include one or more oxide regions 190 disposed above and in contact with the intermediate layer 130. The oxide regions 190 may cover the entire top surface of the top electrode 180 and / or the intermediate layer 130. In other embodiments, only a portion of the top surface intermediate layer 130 is covered by the oxide regions 190. In some embodiments, the oxide may be applied such that the oxide regions 190 contact or completely cover the thickness of the reference layer 140, transition layer 150, fixing region 160, capping region 170, and / or top electrode 180. The oxide regions 190 may conformally surround the magnetoresistive stack and cover the vertical sidewalls of one or more regions of the magnetoresistive stack (e.g., reference layer 140, transition layer 150, fixing region 160, capping region 170, and / or top electrode 180).

[0071] In some embodiments, after forming the oxide region 190, one or more etching processes (e.g., etching, grinding, and / or otherwise polishing processes of one or more layers) may be performed on the oxide-coated magnetoresistive stack. For example, refer to Figure 21 At least a portion of the oxide region 190, the intermediate layer 130, and / or the free region 120 can be removed from the oxide-coated magnetoresistive structure. In some embodiments, at least a portion of the free region 120 can be removed such that one or more sidewalls of the free region 120 have tapered edges (i.e., the free region 120 includes tapered sidewalls). For example, the diameter (e.g., the width in the x or y direction) of the bottom surface of the free region 120 (e.g., the surface in contact with the SH material 110) can be greater than the diameter of the top surface of the free region 120 (e.g., the surface in contact with the intermediate layer 130).

[0072] refer to Figures 22A-22CAfter forming the free region 120 including the tapered sidewalls, at least a portion of the intermediate layer 130, the free region 120, and / or the SH material 110 can be removed to form a stack 200 that is asymmetrical about the longitudinal axis of the SH material 110. For example, the cross-section near the top of the stack 200 (e.g., the cross-section including the top electrode 180 and the oxide region 190) can have a smaller diameter than the cross-section near the bottom of the stack 200 (e.g., the cross-section including the free region 120). In some embodiments, the free region 120 can be “over-etched.” In other words, a portion of the SH material 110 below the etched portion of the free region 120 can also be removed by etching.

[0073] refer to Figure 22A After removing at least a portion of the intermediate layer 130, the free region 120, and / or the SH material 110, the cross-section of the stack 200 in the zy plane is symmetrical about the longitudinal axis of the stack 200. As previously described, when current 302 passes through the SH material 110, spin current 303 is injected from the SH material 110 into the free region 120. Figure 22B As shown, after removing at least a portion of the intermediate layer 130, the free region 120, and / or the SH material 110, the cross-section of the stack 200 in the zy plane is asymmetrical about the longitudinal axis of the stack 200. Figure 22B As shown, towards the removed portion of free region 120 (e.g., towards the sidewall that is no longer conical), the magnetic moments 305 of free region 120 combine to form a total magnetic moment in free region 120. This asymmetric magnetic moment can help impart desired magnetic properties to the stack 200 and / or promote, enhance, maintain, or otherwise assist the transfer of spin current 303 from SH material 110 to free region 120. Although the right wall of free region 120 is in Figure 22B The free region 120 is shown as vertical, but this is only an example. In other embodiments, the free region 120 may still have tapered sidewalls as long as the composite magnetic moment 305 of the free region 120 is asymmetrical.

[0074] Figures 22A-22C The shape of the stack shown can be formed, for example, by performing selective angular etching on a magnetoresistive stack 200 including a free region 120 with tapered sidewalls. As those skilled in the art will recognize, typically, the substrate being etched is rotated during etching (e.g., by ion beam etching (IBE)). In some embodiments, when angular etching is performed, the magnetoresistive structure does not rotate, thereby removing more material on one side of the stack 200 compared to the opposite side of the stack 200.

[0075] Refer again Figure 20The oxide-coated magnetoresistive stack shown can be selectively etched at an angle to remove at least a portion of the oxide region 190. In some embodiments, the magnetoresistive structure is not rotated during the angle etching, thereby removing more material on one side of the stack 200 compared to the opposite side. After removing a portion of the oxide region 190 from the oxide-coated magnetoresistive stack, an asymmetric magnetoresistive stack 200 can be formed, for example... Figure 23 The stack 200 shown.

[0076] Still referencing Figure 23 After at least a portion of the oxide region 190 is removed, the magnetoresistive stack 200 may include one or more oxide regions 190 disposed above and in contact with the intermediate layer 130. The oxide region 190 may cover the entire top surface of the intermediate layer 130 and / or the top electrode 180 of the substrate. In other embodiments, only a portion of the top surface intermediate layer 130 is covered by the oxide region 190. In some embodiments, the oxide region 190 contacts or completely covers the thickness of the reference layer 140, transition layer 150, fixing region 160, capping region 170, and / or top electrode 180. Even after at least a portion of the oxide region 190 is removed, the oxide region 190 may conformally surround the magnetoresistive stack and cover the vertical sidewalls of one or more regions of the magnetoresistive stack (e.g., reference layer 140, transition layer 150, fixing region 160, capping region 170, and / or top electrode 180).

[0077] Selective angular etching is performed on the oxide-coated magnetoresistive stack (resulting in, for example...). Figure 23 Following the asymmetric structure shown, at least a portion of the SH material 110, free region 120, intermediate layer 130, reference layer 140, transition layer 150, fixed region 160, cap region 170, top electrode 180, and / or cap region 170 can be removed to create an asymmetric magnetoresistive structure, for example... Figures 24A-24C The structure shown is illustrated. In some embodiments, at least a portion of the free region 120 may be removed, such that one or more sidewalls of the free region 120 have tapered edges (i.e., the free region 120 includes tapered sidewalls). For example, the diameter (e.g., the width in the x or y direction) of the bottom surface of the free region 120 (e.g., the surface that contacts the SH material 110) may be greater than the diameter of the top surface of the free region 120 (e.g., the surface that contacts the intermediate layer 130).

[0078] refer to Figures 24A-24CAfter forming the free region 120 including the tapered sidewalls, the stack 200 may be asymmetrical with respect to the longitudinal axis of the SH material 110. For example, the cross-section near the top of the stack 200 (e.g., the cross-section including the top electrode 180 and the oxide region 190) may have a smaller diameter than the cross-section near the bottom of the stack 200 (e.g., the cross-section including the free region 120). In some embodiments, the free region 120 may be “over-etched.” In other words, a portion of the SH material 110 beneath the etched portion of the free region 120 may also be removed by etching.

[0079] refer to Figure 24A As shown, after forming the free region 120 with tapered sidewalls, the cross-section of the stack 200 in the zy plane is symmetrical about the longitudinal axis of the stack 200. As previously described, when current 302 passes through the SH material 110, spin current 303 is injected from the SH material 110 into the free region 120. (Reference) Figure 24B After forming the free region 120 with tapered sidewalls, the cross-section of the stack 200 in the zy plane is asymmetrical with respect to the longitudinal axis of the stack 200. For example... Figure 24B As shown, the magnetic moments 305 of the free region 120 combine to form a total magnetic moment in the free region 120 toward the removed portion of the free region 120 (e.g., toward the sidewalls that no longer taper). As described above, this asymmetric magnetic moment can help impart desired magnetic properties to the stack 200 and / or facilitate, enhance, retain, or otherwise assist the transfer of spin current 303 from the SH material 110 to the free region 120. Although the right wall of the free region 120 is shown angled relative to the vertical axis and not parallel to the right wall of the intermediate layer 130, this is merely an example. In other embodiments, the free region 120 may have one or more vertical sidewalls, provided that the composite magnetic moments 305 of the free region 120 are asymmetric.

[0080] Figure 25 This is a flowchart of a method 400 for manufacturing a magnetoresistive structure 100 utilizing STT and / or SOT switching according to one or more embodiments of the present disclosure. Method 400 may include forming SH material segments 110 (step 401). Method 400 may further include forming a magnetoresistive stack 200 including one or more insert layers 201, 202, 203, 204, wherein each insert layer 201, 202, 203, 204 includes an antiferromagnetic material (step 402). In some embodiments, method 400 may include applying a magnetic field to the magnetoresistive stack 200 (step 403). Method 400 may also include annealing the magnetoresistive stack 200, wherein, after annealing, one or more insert layers 201, 202, 203, 204 have magnetic moments parallel or antiparallel to the SH material segments (step 404).

[0081] Figure 26 This is a flowchart of a method 500 for manufacturing a magnetoresistive structure 100 utilizing STT and / or SOT switching according to one or more embodiments of the present disclosure. Method 500 may include forming a magnetoresistive stack 200 comprising a dielectric layer (e.g., intermediate layer 130) and a free region 120 on a segment of SH material 110 (step 501). Method 500 may further include removing at least a portion of one or more layers of the magnetoresistive stack 200, such that at least a portion of the dielectric layer (e.g., intermediate layer 130) is exposed, and forming an etched magnetoresistive stack (step 502). In some embodiments, method 500 may include depositing an auxiliary oxide on the etched magnetoresistive stack to form an oxide region 190 (step 503). Method 500 may further include removing at least a portion of each of the auxiliary oxide (e.g., from oxide region 190), the dielectric layer, and the free region 120 to form a free region 120 comprising tapered sidewalls (step 504). In some examples, method 500 may also include using selective angular etching to remove at least a portion of the free region 120, including the tapered sidewalls (step 505).

[0082] Figure 27 This is a flowchart of a method 600 for manufacturing a magnetoresistive structure 100 utilizing STT and / or SOT switching according to one or more embodiments of the present disclosure. Method 600 may include forming a magnetoresistive stack 200 comprising a dielectric layer (e.g., intermediate layer 130) and a free region 120 on a segment of SH material 110 (step 601). Method 600 may further include removing at least a portion of one or more layers of the magnetoresistive stack 200, such that at least a portion of the dielectric layer (e.g., intermediate layer 130) is exposed, and forming an etched magnetoresistive stack (step 602). In some embodiments, method 600 may include depositing an auxiliary oxide on the etched magnetoresistive stack to form an oxide region 190 (step 603). Method 600 may further include removing at least a portion of the auxiliary oxide using selective angular etching (e.g., removal from oxide region 190) (step 604). In some examples, method 600 may also include removing at least a portion of the auxiliary oxide (e.g., from oxide region 190), dielectric layer (e.g., intermediate layer 130), and free region 120 to form free region 120 including tapered sidewalls.

[0083] As described above, the magnetoresistive device of this disclosure, which includes one or more switching geometries described herein, can be implemented in a sensor architecture or a memory architecture (and other architectures, etc.). For example, in a memory configuration, the magnetoresistive device can be electrically connected to an access transistor and configured to be coupled or connected to various conductors that can carry one or more control signals, such as... Figure 28As shown. The magnetoresistive device disclosed herein can be used in any suitable application, including, for example, in a memory configuration. In this case, according to certain aspects of certain embodiments of the present disclosure, the magnetoresistive device can be formed as an integrated circuit that includes discrete memory devices (e.g., such as...). Figure 29A (as shown), or formed as an embedded storage device having logic therein (e.g., as shown) Figure 29B As shown), each includes an MRAM, and in one embodiment it represents one or more MRAM arrays having multiple magnetoresistive stacks.

[0084] In one embodiment, a magnetoresistive device is disclosed. The device includes a top electrode, a magnetically fixed region, a magnetically free region located above or below the magnetically fixed region, and an intermediate region (e.g., a dielectric layer) located between the magnetically fixed region and the magnetically free region. The magnetoresistive device may further include a spin Hall material adjacent to at least a portion of the free region and an intercalation layer disposed between the spin Hall material and the top electrode, wherein the intercalation layer comprises an antiferromagnetic material.

[0085] Various embodiments of the disclosed magnetoresistive device may additionally or alternatively include one or more of the following features: the intercalation layer may include manganese; the SH material may include at least one of the following: platinum, β-tungsten, tantalum, palladium, hafnium, gold, gold-containing alloys, bismuth and selenium-containing alloys, copper-containing alloys, manganese, iridium, selenium-containing alloys, or one or more combinations thereof; the intercalation layer may have a thickness of less than or equal to about 2.0 nanometers; the intercalation layer may be a first intercalation layer, and the device may further include a second intercalation layer; a transition layer between the dielectric layer and the fixed region, and a cap region between the fixed region and the top electrode, wherein the first intercalation layer, the second intercalation layer, or both are in contact with the cap region or the transition layer; and / or a third intercalation layer is in contact with the cap region or the transition layer.

[0086] In another embodiment, a magnetoresistive device is disclosed. The magnetoresistive device may include a magnetically fixed region, a magnetically free region located above or below the magnetically fixed region, and an intermediate region (e.g., a dielectric layer) located between the magnetically fixed region and the magnetically free region. A spin Hall channel material may be adjacent to at least a portion of the magnetically free region. A cap region may be located on the fixed region opposite to the free region. The device may include a transition layer between the intermediate layer and the fixed region, and at least one insert layer adjacent to the cap region or the transition layer, wherein the at least one insert layer comprises an antiferromagnetic material.

[0087] Various embodiments of the disclosed magnetoresistive device may additionally or alternatively include one or more of the following features: the intercalation layer may include manganese; the intercalation layer may further include iridium or platinum; the intercalation layer may have a thickness of less than or equal to about 2.0 nanometers; a current flowing through the SH material in a first direction may switch the free region to a first magnetic state, and a current flowing in a second direction may switch the free region to a second magnetic state; the fixed region may include a synthetic antiferromagnetic structure (SAF); the at least one intercalation layer may be a first intercalation layer, and the device may further include a second intercalation layer adjacent to the cap region or the transition layer; and / or the device may further include a reference layer between the transition layer and the dielectric layer.

[0088] In another embodiment, a method for manufacturing a magnetoresistive device is disclosed. The method may include forming segments of an SH material and forming a magnetoresistive stack in contact with the SH material, wherein the magnetoresistive stack includes a dielectric layer and free regions configured to switch between a first magnetic state and a second magnetic state. The method may further include removing at least a portion of one or more layers of the magnetoresistive stack to form an etched magnetoresistive stack. The method may further include depositing an oxide (and / or nitride) to form at least one oxide region. The method may further include removing at least a portion of the oxide region and / or removing at least a portion of the free regions to form free regions including tapered sidewalls.

[0089] Various embodiments of the disclosed method may also include one or more of the following features: a second etching step, including: a step of removing at least a portion of the oxide region, a step of removing at least a portion of the free region, or both; selective angular etching; removing at least a portion of one or more layers of the magnetoresistive stack to form the etched magnetoresistive stack may include exposing at least a portion of the dielectric layer; and / or after forming the free region including tapered sidewalls, the magnetoresistive stack may be asymmetrical about the longitudinal axis of the magnetoresistive stack perpendicular to the surface of the SH material that contacts the free region.

[0090] Although various embodiments of the present disclosure have been described and detailed, it will be apparent to those skilled in the art that various modifications can be made without departing from the present disclosure.

Claims

1. A magnetoresistive device, comprising: Top electrode; A fixed region below the top electrode has a fixed magnetic state; The cap area above the fixed area and below the top electrode; A free region below a fixed region, wherein the free region is configured to have a first magnetic state and a second magnetic state; The dielectric layer between the free region and the fixed region; A transition layer between the dielectric layer and the fixed region; A reference layer between the transition layer and the dielectric layer; Spin Hall material adjacent to at least a portion of the free region; and A first insertion layer is disposed between the spin Hall material and the top electrode, in contact with the cap region or transition layer, and a second insertion layer is disposed between the spin Hall material and the top electrode, in contact with the cap region or transition layer, wherein each of the first and second insertion layers comprises an antiferromagnetic material.

2. The apparatus of claim 1, wherein, At least one of the first or second insert layer includes manganese.

3. The device according to claim 1, wherein the spin Hall material comprises at least one of the following: platinum, β-tungsten, tantalum, palladium, hafnium, gold, alloys containing gold, alloys containing bismuth and selenium, alloys containing copper, alloys containing manganese, iridium, and selenium, or one or more combinations thereof.

4. The apparatus of claim 1, wherein the insertion layer has a thickness of less than or equal to 2.0 nm.

5. The device of claim 1, further comprising a third insertion layer, the third insertion layer being in contact with the cap region or the transition layer.

6. A magnetoresistive device, comprising: A fixed region with a fixed magnetic state; The free region is configured to switch between a first magnetic state and a second magnetic state; The dielectric layer between the free region and the fixed region; Spin Hall material adjacent to at least a portion of the free region; The cap area above the fixed area; A transition layer between the dielectric layer and the fixed region; and At least one insert layer is adjacent to the cap region or transition layer, wherein the at least one insert layer comprises an antiferromagnetic material, the transition layer comprises a nonferromagnetic transition metal, and wherein the transition layer is configured to assist in the formation of a reference layer between the dielectric layer and the at least one insert layer.

7. The apparatus of claim 6, wherein, The at least one insert layer comprises manganese.

8. The apparatus of claim 7, wherein, The at least one insert layer also includes iridium or platinum.

9. The apparatus of claim 8, wherein the at least one insertion layer has a thickness of less than or equal to 2.0 nm.

10. The apparatus of claim 6, wherein a current flowing through the spin Hall material in a first direction switches the free region to the first magnetic state, and wherein a current flowing in a second direction switches the free region to the second magnetic state.

11. The apparatus of claim 6, wherein, The fixed region includes a synthetic antiferromagnetic structure (SAF).

12. The apparatus of claim 6, wherein, The at least one insert layer is a first insert layer, and the device further includes a second insert layer adjacent to the cap region or the transition layer.

13. The apparatus of claim 6, further comprising a reference layer between the transition layer and the dielectric layer.

14. A method for manufacturing a magnetoresistive device, the method comprising: The segment that forms the spin Hall material; A magnetoresistive stack is formed in contact with the spin Hall material, wherein the magnetoresistive stack comprises: a fixed region having a fixed magnetic state, a dielectric layer, a free region configured to switch between a first magnetic state and a second magnetic state, a transition layer between the dielectric layer and the fixed region, the transition layer comprising a nonferromagnetic transition metal, and at least one insert layer adjacent to the cap region or the transition layer, the at least one insert layer comprising an antiferromagnetic material. Remove at least a portion of one or more layers of the magnetoresistive stack to form an etched magnetoresistive stack; An oxide is deposited on the etched magnetoresistive stack to form at least one oxide region; Remove at least a portion of the oxide region; and At least a portion of the free region is removed to form a free region including a conical sidewall.

15. The method of claim 14, wherein the step of removing at least a portion of one or more layers of the magnetoresistive stack to form the etched magnetoresistive stack is a first etching step; and The second etching step comprises: The step of removing at least a portion of the oxide region, the step of removing at least a portion of the free region, or both.

16. The method as described in claim 14, characterized in that, The step of removing at least a portion of the oxide region, the step of removing at least a portion of the free region, or both include selective angular etching.

17. The method of claim 14, wherein removing at least a portion of one or more layers of the magnetoresistive stack to form the etched magnetoresistive stack comprises: Exposing at least a portion of the dielectric layer.

18. The method according to claim 14, wherein, After forming a free region including tapered sidewalls, the magnetoresistive stack is asymmetrical about its longitudinal axis, which is perpendicular to the surface of the spin Hall material in contact with the free region.

Images