Magnetic memory with magnetic tunnel contact, using spin-orbit coupling-based switching.

Abstract

Magnetic storage (100, 100', 100'', 100''', 200, 200', 250, 300, 300', 300'', 300''', 300'''', 300''''), comprising the following: a plurality of magnetic contacts (110, 110', 110'', 110''', 210, 260, 310, 310', 310'', 310''', 310''''), wherein each of the plurality of magnetic contacts (110, 110', 110'', 110''', 210, 260, 310, 310', 310'', 310''', 310''') has a data storage layer (112, 112', 112'', 112''', 212, 212''') wherein the data storage layer (112, 112', 112'', 112''', 212) is magnetic; and at least one active spin-orbit coupling layer, active SO layer (120, 120', 120'', 120''', 220, 270, 320, 320', 320', 320'', 320''''), adjacent to the data storage layer (112, 112', 112'', 112''', 212,) of the magnetic contact (110, 110', 110'', 110''', 210, 260, 310, 310', 310'', 310''', 310'''), wherein the at least one active SO layer (120, 120', 120'', 120''', 220, 270, 320, 320', 320'', 320''', 320'''') is configured so that it exerts an SO torque on the data storage layer (112, 112', 112'', 112''', 212) due to a current,which is connected by the at least one active SO layer (120, 120', 120'', 120''', 220, 270, 320, 320', 320''', 320'''', 320'''') in a direction substantially perpendicular to a direction between the at least one active SO layer (120, 120', 120'', 120''', 220, 270, 320, 320', 320'', 320''', 320'''') and the data storage layer (112, 112', 112'', 112''', 212,) of a magnetic contact (110, 110', 110'', 110''', 210, 260, 310, 310', 310'', 310'''', 310'''') of the majority of magnetic contacts (110, 110', 110'', 110'''', 210, 260, 310, 310', 310'', 310''', 310''') nearest to the at least one active SO layer (120, 120', 120'', 120''', 220, 270, 320, 320', 320'', 320''', 320''''); Without the current, at least one active SO layer (120, 120', 120", 120"', 220, 270, 320, 320', 320", 320"', 320"") is also configured to exert no SO torque on the data storage layer (112, 112', 112", 112"', 212), where the data storage layer (112,112', 112", 112"', 212) is configured so that it can be switched using at least the SO torque, , wherein at least one active SO layer (120, 120', 120", 120"', 220, 270, 320, 320', 320", 320"', 320"") extends over at least two of the plurality of magnetic contacts (110, 110', 110", 110"', 210, 260, 310, 310', 310", 310"', 310"").

Description

BACKGROUND OF THE INVENTION

[0001] Magnetic storage devices, especially magnetic random access memories (MRAMs), have attracted increasing interest due to their potential for high read / write speeds, excellent lifetime, non-volatility, and low power consumption during operation. An MRAM can store information using magnetic materials as an information recording medium. One type of MRAM is spin transfer torque (STT) random access memory. An STT-RAM uses magnetic contacts that are at least partially written by a current driven through the magnetic contact. This spin-polarized current exerts a spin torque on the magnetic moments within the contact.As a result, (a) layer(s) which have magnetic moments which react to the spin torque can be switched into a desired state.

[0002] For example, it illustrates Fig. Figure 1 shows a conventional magnetic tunneling junction (MTJ) 10, such as can be used in a conventional STT-RAM. The conventional MTJ 10 is located on a lower contact 11, uses conventional seed layer(s) 12, and has a conventional antiferromagnetic (AFM) layer 14, a conventional pinned layer or reference layer 16, a conventional tunnel barrier layer 18, a conventional free layer 20, and a conventional cover layer 22. The upper contact 24 is also shown. Conventional contacts 11 and 24 are used when driving the current in a current-perpendicular-to-plane (CPP) direction, or along the z-axis, as in Fig. Figure 1 shows that the conventional seed layer(s) 12 are typically used to aid in the growth of subsequent layers, such as the AFM layer 14, which has a desired crystal structure. The conventional tunnel barrier layer 18 is non-magnetic and is, for example, a thin insulator such as MgO.

[0003] The conventional pinned layer 16 and the conventional free layer 20 are magnetic. The magnetization 17 of the conventional reference layer 16 is fixed or pinned in a specific direction, typically by an exchange interaction with the AFM layer 14. Although depicted as a simple (single) layer, the conventional reference layer 16 may have multiple layers. For example, the conventional reference layer 16 may be a synthetic antiferromagnetic (SAF) layer, which has magnetic layers that are antiferromagnetically coupled by thin conductive layers such as Ru. In such an SAF, multiple magnetic layers may be nested or interposed with a thin layer of Ru. In another embodiment, the coupling via the Ru layers may be ferromagnetic.Furthermore, other versions of the conventional MTJ 10 may have an additional pinned layer (not shown) which is separated from the free layer 20 by an additional non-magnetic barrier or conductive layer (not shown).

[0004] The conventional free layer 20 has a variable magnetization 21. Although shown as a single layer, the conventional free layer 20 can also have multiple layers. For example, the conventional free layer 20 can be a synthetic layer, which may have magnetic layers coupled by thin conductive layers, such as Ru, in an antiferromagnetic or ferromagnetic manner. Although shown as in the plane, the magnetization 21 of the conventional free layer 20 can have a perpendicular or perpendicular anisotropy. Similarly, the magnetization 17 of the conventional pinned layer 16 can also be perpendicular to the plane.

[0005] To switch the magnetization 21 of the conventional free layer 20, a current is driven perpendicular to the plane (in the z-direction). The charge carriers are spin-polarized and exert a torque on the magnetization 21 of the conventional free layer. The spin-transfer torque on the magnetic moment 21 of the conventional free layer 20 is initially small when the magnetic moment 21 is parallel to the light axis (the stable state). As such, the stable state of the magnetic moment 21 also corresponds to a stagnation point during switching. Due to thermal fluctuations, the magnetic moment 21 can rotate from an arrangement with the light axis of the conventional free layer 20. The spin-transfer torque can then act to an increasing effect, and the magnetic moment of the free layer 20 is switched.When a sufficient current is driven from the upper contact 24 to the lower contact 11, the magnetization 21 of the conventional free layer 20 can switch so that it is parallel to the magnetization 17 of the conventional reference layer 16. When a sufficient current is driven from the lower contact 11 to the upper contact 24, the magnetization 21 of the free layer can switch so that it is antiparallel to that of the reference layer 16. The differences in the magnetic configurations correspond to different magnetic resistances and therefore different logic states (for example, a logic '0' and a logic '1') of the conventional MTJ 10.

[0006] When used in STT-RAM applications, it is desirable to switch the free layer 20 of the conventional MTJ at a relatively low current to avoid damage to the conventional magnetic contact 10, to reduce the size of the transistor providing this current (not shown), and to lower the power consumption for the memory operation. Additionally, it is desirable to use a short current pulse when programming the conventional magnetic element 10 at higher data rates. For example, current pulses on the order of 20–30 ns or less are desirable to allow the magnetization of the conventional free layer 20 to switch more quickly.

[0007] Although the conventional MTJ 10 can be written using a spin transfer and can be used in an STT RAM, there are disadvantages. For example, the write error rates can be higher than desired for memory with an acceptable pulse width. The write error rate (WER) is the probability that a cell (that is, the magnetization 21 of the free layer 20 of the conventional magnetic contact) will not switch when subjected to a current at least equal to the typical switching current. It is desirable that the WER 10 -9 or less. However, very high currents may be required to achieve switching of the conventional free layer 20 at this WER value. Additionally, it has been determined that the WER can be challenging to achieve an improvement for shorter write current pulses. For example, Fig. 2. A graph 50 shows trends in WERs for pulses of different widths. It should be noted that current data is not shown or plotted in graph 50. Instead, graph 50 is intended to display trends. The pulse width from longest to shortest is shown for curves 52, 54, 56, and 58. As can be seen in graph 50, for higher voltages, the WER applied to contact 10 has a steeper slope. Thus, applying a higher voltage for the same pulse width can result in a significant decrease in the WER. However, as the pulse widths in curves 54, 56, and 58 become shorter, the slope of these curves decreases. For a decreasing pulse width, it is less likely that an increase in voltage and / or current will result in a decrease in the WER.Even high voltages / currents do not lead to a lower error rate with sufficiently short pulses. Consequently, memory modules using the conventional MTJ 10 can have unacceptably high error rates (WER) that cannot be remedied by increasing the voltage.

[0008] Furthermore, although a single magnetic tunnel contact in Fig. As shown in Figure 1, dual magnetic tunnel contacts are often used to obtain a sufficiently high spin-transfer torque for switching. The dual magnetic tunnel contact has a single free layer enclosed, or sandwiched, by two tunnel barrier layers. Each tunnel barrier layer is located between the free layer and a reference layer. The second (upper) tunnel barrier layer of a dual magnetic tunnel contact can be challenging to grow, so it is developed with a suitable crystal structure. Furthermore, to achieve such a high torque, the reference layers have their magnetic moments fixed in opposite directions. As a result, there is a cancellation of the magnetic resistance, which reduces the read signal. Such a reduction in signal is undesirable.

[0009] Therefore, what is needed is a method and a system that improves the performance of spin-transfer torque-based storage devices. The method and system described herein address such a need.

[0010] Document US 2012 / 0098077A1 relates to a writable magnetic element comprising a stack of layers forming a magnetic writing layer, wherein the stack comprises a central layer of at least one magnetic material having a magnetization direction parallel to the plane of the central layer, wherein the layer is arranged between a first and a second outer layer of non-magnetic materials, wherein the first outer layer comprises a first non-magnetic material and the second outer layer comprises a second non-magnetic material different from the first non-magnetic material, wherein at least the second non-magnetic material is electrically conductive.A device is included for allowing a writing current to flow through the second outer layer and the central layer in a current flow direction parallel to the plane of the central layer at an angle α in the range of 90°±60°, in particular 90°±30° and in particular 90°±15° with respect to the magnetization direction, in order to generate an effective magnetic field in the central layer, wherein the current is applied either in a first direction or in a second direction opposite to the first in order to align the magnetization direction in a first magnetization direction or in a second magnetization direction opposite to the first.

[0011] Document US 2012 / 0018822A1 relates to a writable magnetic element comprising a stack of layers having a magnetic writing layer, wherein the stack has a central layer of at least one magnetic material having a magnetization direction perpendicular to the plane of the central layer, wherein the central layer is arranged between a first and a second outer layer of non-magnetic materials, wherein the first outer layer comprises a first non-magnetic material and the second outer layer comprises a second non-magnetic material that is different from the first non-magnetic material, wherein at least the second non-magnetic material is electrically conductive.and comprising a device for causing a current flow through the second outer layer in a current flow direction parallel to the plane of the central layer and a device for applying a magnetic field along a magnetic field direction perpendicular to the plane of the central layer.

[0012] The task is to improve corresponding magnetic storage devices.

[0013] The problem is solved by the magnetic storage device according to claim 1. Further embodiments are described in the dependent claims. BRIEF DESCRIPTION OF SOME VIEWS OF THE DRAWINGS Fig. Figure 1 shows a conventional magnetic contact. Fig. Figure 2 shows a write error rate versus a voltage for a conventional spin-transfer torque RAM. Fig. Figure 3 shows an exemplary embodiment of a magnetic contact which is switched using a spin-orbit coupling or interaction. Fig. Figure 4 shows an exemplary embodiment of another magnetic tunnel contact which is switched using spin-orbit coupling. Fig. Figure 5 shows an exemplary embodiment of voltage pulses used in programming a magnetic contact which is switched using spin-orbit coupling. Fig. Figure 6 shows another exemplary embodiment of a magnetic contact which is switched using spin-orbit coupling. Fig. Figure 7 shows another exemplary embodiment of a magnetic contact which is switched using spin-orbit coupling. Fig. Figure 8 shows another exemplary embodiment of a magnetic contact which is switched using spin-orbit coupling. Fig. Figure 9 shows another exemplary embodiment of a magnetic contact which is switched using spin-orbit coupling. Fig. Figure 10 shows another exemplary embodiment of a magnetic contact which is switched using spin-orbit coupling. Fig. Figure 11 shows another exemplary embodiment of a magnetic contact which is switched using spin-orbit coupling. Fig. Figure 12 shows another exemplary embodiment of a magnetic contact which is switched using spin-orbit coupling. Fig. Figure 13 shows an exemplary embodiment of magnetic contacts which are switched using spin-orbit coupling. Fig. Figure 14 shows another exemplary embodiment of magnetic contacts which are switched using spin-orbit coupling. Fig. Figure 15 shows another exemplary embodiment of magnetic contacts which are switched using spin-orbit coupling. Fig. Figure 16 shows another exemplary embodiment of magnetic contacts which are switched using spin-orbit coupling. Fig. Figure 17 shows another exemplary embodiment of magnetic contacts which are switched using spin-orbit coupling. Fig. Figure 18 shows another exemplary embodiment of magnetic contacts which are switched using spin-orbit coupling. Fig. Figure 19 is a flowchart which represents an exemplary embodiment of a method for providing (a) magnetic contact(s) which are switched using spin-orbit coupling. Fig. Figure 20 is a flowchart which represents an exemplary embodiment of a method for programming (a) magnetic contact(s) which are switched using spin-orbit coupling. DETAILED DESCRIPTION OF THE INVENTION

[0014] The exemplary embodiments relate to magnetic contacts that can be used in magnetic devices, such as magnetic storage devices, and to the devices that use such magnetic contacts. Various modifications to the exemplary embodiments and the generic principles and features described herein will be readily apparent. The exemplary embodiments are described primarily with respect to different methods and systems that are provided for in certain implementations. However, the methods and systems will effectively operate in other implementations as well. Phrases such as "exemplary embodiment," "an embodiment," and "another embodiment" may refer to the same or different embodiments, as well as to multiple embodiments.The embodiments will be described with respect to systems and / or devices that have specific components or parts. However, the systems and / or devices may have more or fewer components than those shown, and variations in the arrangement and type of components are possible. The exemplary embodiments will also be described in the context of specific processes that have certain steps. However, the process and system also work effectively for other processes that have different and / or additional steps and steps in different sequences that are not inconsistent with the exemplary embodiments.

[0015] The exemplary embodiments describe methods and systems for providing a magnetic memory that uses a magnetic contact switched via spin-orbit coupling, as well as a method for programming the magnetic memory. The magnetic memory has magnetic contacts and at least one active spin-orbit (SO) layer. Each of the magnetic contacts has a data storage layer, which is magnetic. The active SO layer(s) are adjacent to the data storage layer of the magnetic contact.The active SO layer(s) is / are configured to exert an SO torque on the data storage layer due to a current passing through the at least one active SO layer in a direction substantially perpendicular to a direction between the at least one active SO layer and the data storage layer of a magnetic contact of the plurality of magnetic contacts that is closest to the at least one active SO layer. The data storage layer is configured such that it is switchable using at least the SO torque.

[0016] The exemplary embodiments are described in the context of specific magnetic contacts and magnetic storage devices that have certain components. A method and system are also described in the context of the current understanding of spin-orbit coupling, spin transfer, magnetic anisotropy, and other physical phenomena. However, the method and system described herein are not dependent on any specific physical explanation. Furthermore, the method and system are described in the context of magnetic contacts, active spin-orbit layers, and / or other structures that have certain layers. In addition, certain components are described as magnetic, ferromagnetic, and ferrimagnetic. When used herein, the term magnetic may include ferromagnetic, ferrimagnetic, or similar structures.Accordingly, when used herein, the terms "magnetic" or "ferromagnetic" include, but are not limited to, ferromagnets and ferrimagnets. The method and system are also described in connection with individual magnetic contacts. Furthermore, when used herein, "in-plane" means substantially within or parallel to the plane of one or more of the layers of a magnetic contact. In contrast, "perpendicular" corresponds to a direction that is substantially perpendicular to one or more of the layers of the magnetic contact.

[0017] Fig. Figure 3 shows an exemplary embodiment of a section of a magnetic memory 100 which uses spin-orbit coupling during switching. For clarity, Fig. Figure 3 is not to scale. Additionally, sections of the magnetic memory 100, such as bit lines, row and column selectors, and selection devices such as transistors for each cell, are not shown. The magnetic memory 100 comprises a magnetic contact 110 and an active spin-orbit coupling (SO) layer 120. The magnetic contact 110 can be part of a memory cell, which may also include selection device(s) such as transistor(s) and / or other magnetic contacts.

[0018] In the embodiment shown, the magnetic contact 110 comprises a data storage layer 112, a non-magnetic spacer layer 114, and a reference layer 116. The spacer layer 114 is non-magnetic. In some embodiments, each spacer layer 114 is an insulator, for example, a tunnel barrier layer. In such embodiments, each spacer layer 114 may comprise crystalline MgO, which may increase the TMR and spin transfer efficiency and / or spin-orbit coupling for the magnetic contact 110. In other embodiments, the spacer layer 114 may be a conductor, such as Cu. In alternative embodiments, the spacer layer 114 may have a different structure, for example, a granular layer having conductive channels in an insulating matrix.

[0019] The data storage layer 112 is a free layer 112 which has a switchable magnetic moment (not shown). When the magnetic contact 110 is inactive (not switched), the magnetic moment of the free layer 112 lies along the light axis of the free layer 112. It is desirable that the magnetic moment of the reference layer 112 be substantially fixed in place during operation of the magnetic storage 100. The reference layer 116 is shown as a single layer. In other embodiments, however, the reference layer 116 can be a multilayer which includes, but is not limited to, a synthetic antiferromagnet, having ferromagnetic layers separated by a non-magnetic layer(s), which may be Ru.In some embodiments, the magnetic contact 110 also includes a pinning layer, such as an antiferromagnetic layer (not shown), which fixes the magnetic moment of the reference layer 116 in place. In other embodiments, the magnetic moment of the reference layer 116 is fixed in a different manner. The free layer and the reference layer 112 and 116 are ferromagnetic and can therefore contain one or more of Fe, Ni, and Co. Although magnetic moments are not shown, the magnetic moments of layers 112 and 116 can be perpendicular to the plane in some embodiments. Accordingly, each of layers 112 and / or 116 can have a perpendicular anisotropy field, which corresponds to its out-of-plane demagnetization field (typically a significant fraction of 4πM). s). In other embodiments, the magnetic moments are in the plane.

[0020] The magnetic moment of the free layer 112 is switched using the spin-orbit coupling effect, which is described below. In some embodiments, the magnetic moment of the free layer 112 is switched using only the spin-orbit coupling effect. In other embodiments, however, the free layer 112 can be switched using a combination of effects. For example, the magnetic moment of the free layer 112 can be switched using a spin-transfer torque as a primary effect, which may be supported by a torque induced by spin-orbit coupling. In other embodiments, however, the primary switching mechanism is a torque induced by spin-orbit coupling.In such embodiments, another effect, including but not limited to spin transmission torque during switching and / or selecting the magnetic contact 110, may provide support.

[0021] The active SO layer 120 is a layer that exhibits strong spin-orbit coupling and can be used to switch the magnetic moments of the free layer 112. The active SO layer 120 can be used to generate a spin-orbit field H. SO can be used. More precisely, a current driven in a plane through the active SO layer 120 and the accompanying spin-orbit coupling can be used to generate the spin-orbit field H. SO lead. This spin-orbit field H SO is equivalent to the spin-orbit torque T SO , on a magnetization T SO = -γ[MxH SO] in the free layer 112. This mutually correlated torque and field are therefore referred to interchangeably as a spin-orbit field and a spin-orbit torque. This reflects the fact that spin-orbit coupling is the origin of the spin-orbit torque and the spin-orbit field. This terminology also distinguishes this spin-orbit (SO = spin orbit) torque from the more conventional spin-transfer torque (STT = spin transfer torque). A spin-orbit torque occurs for a current driven in a plane in the active SO layer 120 and spin-orbit coupling. In contrast, a spin-transfer torque is expected due to a current perpendicular to the plane, flowing through the free layer 112, the spacer layer 114, and the reference layer 116, which injects spin-polarized charge carriers into the free layer 112. The spin-orbit torque T SOThe magnetic moment of the free layer 112 can quickly deflect or displace it from its equilibrium state parallel to the light axis. The spin-orbit torque T SO The magnetization of the free layer can tend to change considerably faster than a conventional STT torque of a similar maximum amplitude. In some embodiments, switching can be completed using a spin-orbit torque. In other embodiments, a different mechanism, such as a spin transfer, can be used to complete a switching operation. The spin-orbit field / spin-orbit torque that is generated can therefore be used to switch the magnetic moment of the free layer 112.

[0022] In some embodiments, the SO layer can exhibit several combinations of two effects: the spin Hall effect and the Rashba effect. In many active SO layers, spin-orbit coupling exhibits both the spin Hall effect and the Rashba effect. However, one of the two dominates. Accordingly, the spin Hall effect and the Rashba effect are described below. The spin Hall effect is generally considered to be a bulk effect. Materials exhibiting the spin Hall effect often contain heavy metals or are doped with heavy metals. For example, such materials can be selected from X doped with M and Y doped with M.X includes Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Cd, In, Sb, Te, Hf, Ta (including a high-resistance amorphous β-Ta), W, Re, Os, Ir, Pt, Au, Hg, Tl, Pb, Bi, Po, At, and / or their combinations; M includes at least one of Al, Ti, V, Cr, Mn, Cu, Zn, Ag, Hf, Ta, W, Re, Pt, Au, Hg, Pb, Si, Ga, GaMn or GaAs, and Y includes at least one of V, Cr, Mn, Fe, Co, Ni, P, S, Zn, Ga, Ge, As, Se, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, In Sb, Te, I, Lu, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg, Tl, Pb, Bi, Po, At, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb. In some embodiments, the active SO layer may include 120 or consist of Ir doped with Cu and / or Bi doped with Cu. The doping level is generally in the range of 0.1 to 10 atomic percent. Other materials can be used in other embodiments.

[0023] For the spin Hall effect, a current J is used. SOin the plane of the active SO layer 120 (that is, an in-plane current, essentially in the xy-plane in Fig. 3) driven. In other words, the current is driven perpendicular to the direction between the active SO layer 120 and the data storage / free layer 112 (that is, perpendicular to the normal to the surface, perpendicular to the z-direction in Fig. 3) Charge carriers having spins of a specific orientation perpendicular to the direction of the current and to the surface normal (z-direction) accumulate on the surfaces of the active SO layer 120. In the embodiment described in Fig. As shown in Figure 3, the charge carriers, which have spins in the y-direction, accumulate at the surface or at the top of the active SO layer 120, which is described by a unit polarization vector p SOFigure 122 shows that many of these spin-polarized charge carriers diffuse into the free layer. This diffusion leads to the torque T. SO on the magnetization of the free layer 112. Since a torque on the magnetization is equivalent to the effective field on the magnetization, it can be determined by T SO = -γ[MxH SO ] can be expressed equivalently as the spin accumulation corresponding to the field H SO on the free layer 112. The spin-orbit field for the spin Hall effect is the cross product of the spin-orbit polarization 122 and the magnetic moment of the free layer 112 and is given by: HSO α(JSO*PSO / 2t*e)mxpSO

[0024] Here, t is the thickness of the free layer 112, e is the electron charge, m is the unit vector along the magnetization of the data storage layer 112, and p SOis the unit vector along the direction of spin polarization 122. As such, the magnitude of the torque is proportional to an in-plane current density J. SO and a spin polarization of the charge carriers P SO For some embodiments in which the spin Hall effect is the only SO coupling or SO interaction, P SO directly related to the so-called Hall angle Τ SO In general, P SO A characteristic of the geometry and material(s) used for the active SO layer 120 and for the adjacent layers. For different materials, the P SO The values ​​should be 0.1–1. Larger values ​​of the SO polarization P SO This leads to larger polarizations and therefore larger spin orbit fields and torques.

[0025] The spin Hall effect can be used when switching the magnetic contact 110 if the polarization caused by the spin Hall effect p SO The induced torque is parallel to the light axis of the free layer 112. To determine the spin-orbit torque T SO To obtain this, the current pulse is driven in the plane through the active SO layer 120. The resulting spin-orbital torque T SO This counteracts a damping torque, which leads to the switching of the magnetization of the free layer 112 in an analogous manner to conventional STT switching.

[0026] Another source of the spin orbit field H SOIn the active SO layer 120, the spin-orbit coupling at the interfaces or transitions can be related. The magnitude of the spin-orbit field in this case often relates to the size of the crystal field, which is frequently high at the transition. Due to the mismatch of the lattice parameters of the adjacent layers, the presence of heavy metals at the transition, and other effects, the spin-orbit coupling at some transitions can be considerably large. A strong spin-orbit effect at the transition, which is associated with the gradient of the crystal field in the perpendicular direction to the transition plane, is often referred to as the Rashba effect. However, when used here, the Rashba effect refers to spin-orbit coupling at the transition regardless of its origin and direction.It should be noted that in at least some embodiments, the transitions for the active SO layer 120 should differ in order to achieve a significant Rashba effect. For example, the Rashba effect can occur for the active SO layer 120, which is / has a Pt layer adjacent to the magnetic contact 110, a Co layer for the free layer 112, and an aluminum oxide or a non-magnetic MgO layer 114. In some embodiments, other materials can be used.

[0027] The effect of spin-orbit coupling at the junction (i.e., the Rashba effect) on the magnetization is twofold. First, spin accumulation can build up at the junction. The unit vector of the spin polarization of this spin accumulation is p. SOThe Rashba effect is typically perpendicular to the crystal field and the current direction. Many active SO layers 120 have a crystal field perpendicular to the plane of the layer 120. As such, the spin-orbit polarization would be p SO 122 in one plane, as in Fig. Figure 3 shows that, alternatively, the SO layer 120 can have a crystal field in the plane or inclined to the plane. As such, the active SO layer 120 has a spin-orbit polarization perpendicular to the plane (not shown) in Fig. 3 or inclined accordingly to the plane (in Fig. 3 not shown). In such embodiments, the active SO layer 120 can be a surface alloy. For example, the active SO layer 120 can comprise at least one of Cu, Zn, Ga, Ge, As, Se, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, In, Sn, Sb, Te, I, Lu, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg, Tl, Pb, Bi, Po, At, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and / or combinations thereof. In other embodiments, the active SO layer 120 can comprise surface alloys of X / Y, for example, atoms of X located on a (111) surface of a host material Y such that the top surface contains atomic layers of a mixture of X and Y. X contains at least one of Cu, Zn, Ga, Ge, As, Se, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, In, Sn, Sb, Te, I, Lu, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg, Tl, Pb, Bi, Po, At, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Y contains at least one of Si, Zn, Cu, Ag, Au, W, Zn, Cr, Pt, Pd.In many embodiments, X comprises two or three different materials. In some embodiments, at least 0.1 to no more than three monolayers of X are deposited. In some such embodiments, approximately ⅓ of a monolayer of X is deposited. In some embodiments, this may be one or more of the following: substitution Bi / Ag, substitution Pb / Ag, substitution Sb / Ag, substitution Bi / Si, substitution Ag / Pt, substitution Pb / Ge, substitution Bi / Cu, and a bilayer or bilayer comprising a layer located on a surface of Au, Ag, Cu, or Si. In other embodiments, alloys such as InGaAs, HgCdTe, or bilayers LaAlO3 / SrTiO may be used. 3, LaTiO3 / SrTiO3 are used. In other embodiments, other materials can be used. For some embodiments, the Rashba effect is converted to the spin-orbital torque T. SO and a corresponding spin-orbit field H SOto the free layer, which is given by the expression in paragraph

[039] . Here, the unit polarization vector p can be SO be in the plane, inclined, or perpendicular to the plane, as explained above. The polarization P SO For the Rashba effect, the value can be 0.1–1 for some embodiments; for some other embodiments, it can be greater than 1. Larger values ​​of polarization P SO This leads to larger polarizations and therefore larger spin-orbit fields. In other embodiments, the Rashba effect can lead to the spin-orbit field influencing the magnetization of the free layer, which is given by: HSO α(JSO*PSO / 2d*e)pSO

[0028] For the Rashba effect, the magnitude or order of magnitude of the spin-orbit torque due to the spin-orbit field is proportional to the in-plane current density J. SO and the polarization P SO J SOis therefore perpendicular to the direction between the active SO layer 120 and the free layer 112 (that is, in the xy-plane and perpendicular to the surface normal). Again, p SO The unit vector in the direction of spin-orbit polarization. The spin-orbit polarization P SO For these embodiments, a characteristic of the material(s) used for the active SO layer 120 is required. The polarization P SO For the Rashba effect, the polarization can be 0.1–1 for some embodiments. For some other embodiments, the polarization can be greater than 1. Larger values ​​of polarization P SO This leads to larger polarizations and therefore larger spin-orbit fields. For other embodiments, the spin-orbit field H SOThe Rashba effect is given by a combination of two terms, one given by an equation in paragraph

[042] and another in

[046] . The contribution of each of these terms depends on the material and the geometric properties of the transition.

[0029] If the unit polarization vector p SO Because the Rashba effect is parallel to the light axis of the free layer 112, the Rashba effect can be used to switch the magnetic contact 110, similar to what is described for the spin Hall effect. To switch the free layer 112, an in-plane current pulse (J) is applied. SO ) driven through the active SO layer 120. The current pulse generates the spin-orbit field H. SOin the manner described above. The torque corresponding to the component of the SO field given by the equation in paragraph

[042] will be directed opposite to the magnetic damper torque and can switch a magnetization of the free layer in an analogous manner to STT and similar to that discussed above for the spin Hall effect. The component of the SO field given by the equation in paragraph

[046] is opposite to the intrinsic anisotropy field of the free layer Hk. If H SO becomes larger than H K The magnetization also switches. If both components of the spin-orbit field are present, two effects can help each other. It should be noted that in the preceding case (T SO becomes larger than the damping term) the spin-orbit field H SO typically 1 / α × smaller than what is needed for the latter case (H SObecomes larger than the anisotropic field H K ), where α is the Gilbert damping constant of the free layer, typically 0.001-0.05.

[0030] Accordingly, the magnetic memory 100 can utilize the spin-orbit coupling and the spin-orbit field generated by the SO layer 120 when switching the magnetic moment of the free layer 112. In some embodiments, the active SO layer 120 can rely on one or both of the spin Hall effect and the Rashba effect to generate the spin-orbit field H. SOto generate. Accordingly, when used herein, terms such as "spin-orbit effect," "spin-orbit field," and / or "spin-orbit couplings" may include spin-orbit coupling via the Rashba effect, the spin Hall effect, some combinations of the two effects, and / or some other spin-orbit couplings or interactions, or spin-orbit coupling-like effects. The spin-orbit fields may exert a torque on the magnetic moment of the data storage / free layer 112. This spin-orbit torque may be used in switching the magnetic moment of the free layer 112. In some embodiments, the spin-orbit field assists in switching the magnetic moment of the free layer 112. Another mechanism, such as a spin-transfer torque, is the primary switching mechanism. In other embodiments, the spin-orbit torque is the primary switching mechanism for the magnetic moment of the free layer 112.In some embodiments, however, the spin-orbit torque can be assisted by another mechanism, such as a spin-transfer torque. This assistance can occur during the switching of the magnetic moment of the free layer 112 and / or during the selection of the magnetic contact to be switched.

[0031] Since the spin-orbit torque can be used to switch the magnetic moment of the free layer 112, the performance of the memory 100 can be improved. As discussed above, the spin-orbit torque generated by the active SO layer 120 can reduce the switching time of the magnetic contact 110. The spin-orbit torque typically has a high efficiency P SO and is proportional to the current J SOSince this current density is in the plane and does not flow through the spacer layer 114, the spin-orbit current can be increased without damaging the magnetic contact 110. As a result, the spin-orbit field and spin-orbit torque can be increased. Consequently, the write time can be reduced and the write error rate improved. Therefore, the performance of the memory 100 can be improved.

[0032] Fig. Figure 4 represents an exemplary embodiment of a magnetic storage device 100'. For clarity, Fig. Figure 4 is not to scale. The magnetic memory 100' is analogous to the magnetic memory 100. Accordingly, similar components have analogous designations. The magnetic memory 100' therefore has a magnetic contact 110' and an active SO layer 120', which are analogous to the magnetic contact 110 and the active SO layer 120, respectively. The magnetic contact 110' has a data storage / free layer 112', a non-magnetic spacer layer 114', and a reference layer 116', which are analogous to the storage / free layer 112, the non-magnetic spacer layer 114, and the reference layer 116, respectively. Accordingly, the structure and function of components 110' and 120' are analogous to those described above for components 110 and 120. The magnetic moment 113' of the free layer 112' is stable perpendicular to the plane.The magnetic moment 113' is therefore parallel to the light axis 115' of the free layer 112' in the embodiment shown, and the magnetic moment 117' of the reference layer 116' is likewise perpendicular to the plane.

[0033] The primary switching mechanism for the magnetic contact 110' is a spin-transmission torque. Accordingly, a switching current J STT The primary switching current is driven perpendicular to the plane (along the z-axis) through the magnetic contact 110'. However, a spin-orbit coupling torque is used to assist the switching. The in-plane spin-orbit current J SO is therefore driven by the active SO layer 120'. The spin-orbit current is in the xy-plane, which is also the plane of the layers of memory 100'. The active SO layer 120' has a spin-orbit polarization, which generates spin-orbit fields such as H. SO can arise. The spin orbit field HSO It can have components due to the spin Hall effect, the Rashba effect, or both. Furthermore, although shown perpendicular to the in-plane spin orbit current, in other embodiments the spin orbit field can be in a different direction. The active SO layer 120' can have the same structure, function, and constituent material(s) as described above. Accordingly, the active SO layer 120' can be used to assist in switching the magnetic contact 110'.

[0034] To assist in switching the magnetic contact 110', the spin-orbit polarization p SO perpendicular to the light / stable axis 113' of the free layer 112. The light axis 115' is perpendicular to the plane, while the spin-orbit polarization lies in the plane (for example, in the xy-plane). The spin-orbit torque T SOThe perpendicularity to the plane magnetic moment of the free layer 112' can quickly deflect from its equilibrium state parallel to the light axis. The spin-orbital torque T SO can be maximized in the initial position, thus enabling a remarkably large inclination of the magnetic moment of the free layer 112' at the beginning after the SO current pulse is applied. Accordingly, the spin-orbital torque T inclines SO The magnetization of the free layer is remarkably faster than a conventional STT torque of a similar maximum amplitude. Indeed, for a conventional magnetic moment of a reference layer that is collinear with the magnetic moment of the free layer, the conventional STT torque is small in the first few moments after the STT pulse is applied. SOThe magnetic moments of the free layer are similarly inclined to states corresponding to a logical 1 or 0 (the top and bottom positions of the magnetic moment, respectively). However, the magnetic moment cannot readily switch to the opposite orientation. Therefore, a spin-carry torque (STT) can be applied to switch the magnetic moment of the free layer 112'. In addition to the in-plane current pulse for the active SO layer, an STT current pulse can be driven perpendicular to the plane to complete the switching. The STT torque is greater for larger inclinations of the magnetization of the free layer 112' from the equilibrium position. The STT torque reaches a maximum when the magnetic moment of the free layer 112' is perpendicular to the light axis 115' of the free layer. Therefore, if the magnetization is notably influenced by the SO torque T SOIf inclined, then the STT torque switches the magnetization faster. Since the spin-orbit torque T SO Since the magnetization can be quickly tilted from the equilibrium position, and in this tilted position the STT torque can quickly switch the magnetization to a new equilibrium position, the overall switching time can be significantly reduced compared to the case where only the conventional STT torque is used. Furthermore, write error rates can be significantly improved. Therefore, spin-orbit coupling can be used to assist in switching the magnetic moment of the free layer 112'.

[0035] Since the total switching time for larger inclinations of the magnetization of the free layer 112' is determined by the spin-orbit torque T SO If it is reduced, it is for the size of the spin-orbit torque T SO and a corresponding field H SOIt is important that it is sufficiently high. Therefore, it is desirable that the spin-orbit field be a significant percentage of the anisotropy field for the magnetic contact 110'. In some embodiments, it is desirable that the spin-orbit field be at least 10% and no more than 50% of the anisotropy field for the magnetic contact 110'. In other embodiments, however, the spin-orbit field may have a different value.

[0036] To reliably tilt the magnetization of the free layer, the SO field pulse is sufficiently short for some embodiments. In such embodiments, the total duration of the SO field pulse is less than half the magnetization precession time for increased performance. For some embodiments, the magnetic precession time is equal to 1 / 2 (2π / γH). K ), where H KThe anisotropy field of the free layer 112' is given. Therefore, the SO current pulse can be at least 30 ps and no more than 3 ns long, but it depends on Hk. If, instead, the transmitted pulse width is on the order of the precession time (2π / γH) K (for some embodiments) then the magnetic moment returns to the stagnation point parallel to the light axis. The SO field H R This cannot improve the switching speed. If the pulse width is longer than the oscillation duration, for example 1 nanosecond or more, then any potential magnetization tendency cannot be controlled.

[0037] For some other embodiments, if the SO field H SO which has the form described in the expression in paragraph

[039] , and the H SO -field is sufficiently high, the spin-orbit field H SOable to rotate the magnetic moment of the free layer 112' as far as parallel (or antiparallel) to the polarization vector p SO For a free layer 112', whose light axis is perpendicular to the plane, this corresponds to an orientation perpendicular to the light axis. In this case, this results in a very large amplitude of the SO torque T. SO As long as the current pulse is driven through the active SO layer 120', the magnetic moment can remain rotated from the light axis. Therefore, if the spin-orbit current pulse has a sufficiently large size and width, the magnetic moment can remain pinned in the plane due to the spin Hall effect. For such embodiments, there is no limit to the duration of the SO field pulse. Furthermore, the STT is maximized when the initial inclination of the free layer magnetization is perpendicular to the light axis.

[0038] If the inclination of the free layer magnetization due to the spin-orbit torque is not very large (for example, less than π / 4 radians for some embodiments) and no STT torque is applied, then the magnetization can return to the initial magnetic state after the end of the SO field pulse. However, if the inclination is larger, the magnetization has a high chance of returning in the opposite direction. If the inclination, which is determined by T SO If the induced current is approximately π / 2 and no STT pulse is applied, the magnetization may have an equal chance of returning to the initial state and switching to the opposite state. Therefore, for a large inclination caused by T SO Information is induced in the cell by the spin-orbital torque T. SObe disturbed or erased. For some embodiments, an optimal inclination due to the SO effect is determined by the balance between speed (larger inclinations) and a limitation on the non-disturbance of the initial memory state (smaller inclinations).

[0039] To switch the magnetic moment 113' of the free layer 112', an in-plane spin orbit (SO) current pulse (J) is applied. SO ) through the active SO layer 120'. In other words, the spin-orbit current pulse is driven perpendicular to the direction between the active SO layer 120' and the free layer 112' (for example, perpendicular to the z-direction). The SO current pulse generates the spin-orbit field H. SO in the manner described above. The spin-orbit field H SOThe magnetic moment 113' of the free layer 112' is disturbed from its equilibrium state along the light axis 115' for sufficiently short pulse widths of the current J. SO If the spin-carry current J STT When applied, the magnetic moment 113' of the free layer 112' can be switched. The switching of the magnetic contact 110' can be improved. For example, Fig. 5 a graph 150, which represents the timing of current pulses used in programming memory 100'. Referring to the Fig. Plots 152 and 154, shown in graph 150, are shown for illustrative purposes only and are not intended to represent specific pulses of the real world.

[0040] A SO current pulse 152, which has a width t SO and a size J SO has, is driven by the active SO layer 120'. It is desirable that the width t SOThe short duration of the SO current pulse 152 is desirable to ensure that the magnetic moment 113', which is perturbed by any section of the spin-orbit field generated by the Rashba effect, does not precess back to the stagnation point. Therefore, it is desirable that the width of the SO current pulse 152 be relatively narrow, for example, 0.1–3 nanoseconds. In some such embodiments, the width of the SO current pulse 152 is on the order of 30 picoseconds to 0.1 nanoseconds. Furthermore, since the SO current pulse 152 lies in the plane of the active SO layer 120', its magnitude, or order of magnitude, can be large. For example, the current density J can be SO on the order of 1×10 8 A / cm 2 to be, if the free layer has a high H K has a current on the order of 0.01–1 mA. For some other applications, the current density can be on the order of 1 × 10 7 A / cm 2be.

[0041] After the start of the SO current pulse, the spin transfer torque (STT) current pulse 154, which has a width t STT and a size J STT has been driven perpendicular to the plane through the magnetic contact 110'. Accordingly, the STT current pulse 154 can begin before the magnetic moment 113' has a chance to precess back to the stagnation point. In the embodiment described in Fig. As shown in Figure 5, the STT current pulse 154 begins before the SO current pulse 152 ends. In other embodiments, however, the STT current pulse 154 can start at or after the SO current pulse 152 has ended. If the STT current pulse 154 starts after the SO current pulse 152 has ended, then it is desirable that only a small amount of time, for example, no more than a few oscillation durations or oscillation periods of the magnetic moment 113', elapses between the end of the SO current pulse 152 and the start of the STT current pulse 154. The magnitude of the STT current pulse 154 can be significantly smaller than that of the SO current pulse 152, since the STT current pulse 154 is perpendicular to the plane. For example, J STT on the order of 1×10 6 A / cm 2The width of the STT current pulse 154 can be as long as is required to switch the magnetic contact 110'. However, since the SO current pulse 152 is also used, the switching can be even faster.

[0042] Using current pulses 152 and 154, the magnetic storage 100' can be switched faster. The SO current pulse 152 through the active SO layer 120' generates a spin-orbit field that perturbs the magnetic moment 113 from the stagnation point along the light axis 115'. The spin-transfer torque due to the STT current pulse 154 through the magnetic contact 110' can then have a greater effect on switching the magnetic moment 113'. Thus, the STT torque can be used to switch the magnetic moment 113' of the magnetic contact 110' faster.

[0043] Since the spin-orbit torque can be used when switching the magnetic moment 113' of the free layer 112', the performance of the memory 100' can be improved. The spin-orbit torque generated by the active SO layer 120' allows the magnetic contact 110' to be programmed at an increased speed. Because the spin-orbit torque has high efficiency and is proportional to the size of the in-plane spin-orbit current pulse 152, the spin-orbit torque can be large. The large spin-orbit torque can therefore disturb the magnetic moment 113 from the stagnation point. The width and size of the spin-transfer torque pulse 154 can be reduced while writing to the magnetic memory 100'. Consequently, the write time can be reduced and the write error rate improved. The performance of the memory 100' can thus be improved.

[0044] Fig. Figure 6 represents an exemplary embodiment of a 100'' magnetic storage device. For clarity, Fig. Figure 6 is not to scale. The magnetic memory 100'' is analogous to the magnetic memory 100. Consequently, similar components have analogous designations. The magnetic memory 100'' therefore has a magnetic contact 110'' and an active SO layer 120'', which are analogous to the magnetic contact 110 and the active SO layer 120, respectively. The magnetic contact 110'' has a data storage / free layer 112', a non-magnetic spacer layer 114'', and a reference layer 116'', which are analogous to the storage / free layer 112, the non-magnetic spacer layer 114, and the reference layer 116, respectively. Therefore, the structure and function of components 110'' and 120'' are analogous to those described above for components 110 and 120. The magnetic moment 113'' of the free layer 112' is stable in the plane.The magnetic moment 113'' is therefore parallel to the light axis 115'' of the free layer 112''. In the embodiment shown, the magnetic moment 117'' of the reference layer 116'' is also in the plane. For some embodiments, this in-plane light axis direction is perpendicular to the direction of the current J. SO in the SO layer 120''. One result is p SO parallel to the slight axis 115'' of the free layer 112''.

[0045] The magnetic contact 110'' is switched using a spin-orbit torque as the primary switching mechanism. In some embodiments, the spin-orbit torque is generated by the spin Hall effect and / or the Rashba effect. The active SO layer 120'' can therefore have the same structure, function, and constituent material(s) as described above. The in-plane current J SOThe current driven by the active SO layer 120' is the primary switching current. However, other mechanisms, discussed below, can be used in selecting the magnetic contact 110'' and thus assist in programming the magnetic contact 110''. Furthermore, other mechanisms and / or other materials can be used in other embodiments.

[0046] To program the magnetic contact 110'', the spin-orbit field is generated, whereby the spin-orbit polarization p SO along the light / stable axis 115'' of the free layer 112'' in the direction in which the magnetic moment 113'' is desired to be switched. The spin-orbit current required to be driven through the active SO layer 120'' is on the order of J STT -some MA / cm 2 In the embodiment which is described in Fig. As shown in Figure 6, it is desirable for the magnetic moment 113'' to change direction so that it is in the +y direction. To switch the magnetic moment 113'' to the -y direction, the spin-orbit current J is SO driven in the opposite direction to that shown. The spin-orbit field 122'', which is generated by the spin-orbit coupling, applies a spin-orbit torque to the magnetic moment 113'', which switches the magnetic moment 113'' in the desired direction.

[0047] Since the spin-orbit torque switches the magnetic moment 113'' of the free layer 112'', the efficiency of the memory 100' can be improved. Since the SO current is in-plane for the active SO layer 120'', and therefore does not flow through the spacer layer 114'', the current density J can be increased. SO be large. For example, the current density can be on the order of 1×10 8 A / cm 2This would correspond to a current on the order of 0.01–1 mA. Such a large current can generate a large spin-orbit field and therefore a greater spin-orbit torque on the magnetic contact 113''. In other words, an overdrive stage of the magnetic contact 110'' can be achieved more easily. Furthermore, the magnetic contact 110'' can be a single magnetic contact instead of a dual magnetic contact with two reference layers. This can lead to issues such as magnetoresistance cancellation and issues with the growth of the barrier layers in a dual contact. Therefore, the performance of the memory 100'' can be improved.

[0048] Fig. Figure 7 represents an exemplary embodiment of a magnetic storage device 100'''. For clarity, Fig. Figure 7 is not to scale. The magnetic memory 100''' is analogous to the magnetic memories 100 / 100''. Consequently, similar components have similar designations. The magnetic memory 100'' therefore has a magnetic contact 110''' and an active SO layer 120''', which are analogous to the magnetic contact 110 / 110'' and the active SO layer 120 / 120''. The magnetic contact 110''' has a data storage / free layer 112'', a non-magnetic spacer layer 114''', and a reference layer 116''', which are analogous to the storage / free layer 112 / 112'', the non-magnetic spacer layer 114 / 114'', and the reference layer 116 / 116''. Accordingly, the structure and function of components 110''' and 120''' are analogous to those described above for components 110 / 110'' and 120 / 120''. The magnetic moment 113'' of the free layer 112'' is stable and perpendicular to the plane.The magnetic moment 113'' is therefore parallel to the light axis 115''' of the free layer 112''. In the embodiment shown, the magnetic moment 117''' of the reference layer 116''' is also perpendicular to the plane.

[0049] The magnetic contact 110'' is switched using a spin-orbit torque as the primary switching mechanism. In some embodiments, the spin-orbit torque is generated by the Rashba effect. The active SO layer 120'' can therefore have the same structure, function, and constituent material(s) as described above for the Rashba effect. In other embodiments, however, other mechanisms and / or materials may be used. The in-plane current J SOThe current driven by the active SO layer 120''' is the primary switching current. However, other mechanisms can be used in selecting the magnetic contact 110''' and thus support the programming of the magnetic contact 110''.

[0050] To program the magnetic contact 110''', the spin-orbit field is generated, where the spin-orbit polarization p SO along the light / stable axis 115'' of the free layer 112''' in the direction in which the magnetic moment 113''' is desired. In some embodiments, the spin-orbit field is primarily or entirely generated by the Rashba effect. The spin-orbit current required to drive through the active SO layer 120''' is on the order of J STT - some MA / cm 2 In the embodiment which is described in Fig. As shown in Figure 7, it is desirable for the magnetic moment 113''' to change direction so that it is in the +z direction. To switch the magnetic moment 113''' to the -z direction, the spin-orbit current J is SO driven in the opposite direction to that shown. The spin-orbit field 122''', which is generated by the spin-orbit coupling, applies a spin-orbit torque to the magnetic moment 113', whereby the magnetic moment 113'' is switched in the desired direction.

[0051] The magnetic storage 100''' shares the advantages of the magnetic storage 100''. Since the spin-orbit torque switches the magnetic moment 113''' of the free layer 112''', the performance of the storage 100'' can be increased. Since the SO current for the active SO layer 120'' is in the plane, the current density J can be SObe large. Therefore, an overdrive stage of the magnetic contact 110'' can be achieved more easily. Furthermore, the magnetic contact 110'' can be a single magnetic contact instead of a dual magnetic contact, which has two reference layers. Therefore, there are issues such as magnetoresistance cancellation and issues with the growth of the barrier layers for a dual contact. Therefore, the performance of the memory 100'' can be improved.

[0052] Accordingly, spin-orbit coupling can be used as a mechanism for switching the magnetic moment of the data storage / free layer 112 / 112' / 112" / 112" of a magnetic contact. Spin-orbit coupling can assist in switching, such as spin-transfer-moment switching, or it can be used as the primary switching mechanism. Spin-orbit coupling allows for higher torque because the in-plane spin-orbit current can be greater, enabling faster switching with improved write error rates. Additionally, the use of dual magnetic contacts, which are favored for STT RAM memory but have a number of disadvantages, can be avoided. Consequently, the performance of magnetic memory 100, 100', 100" and / or 100'' can be improved.

[0053] Fig. Figure 8 represents an exemplary embodiment of a magnetic storage device 200 which uses or employs a magnetic contact 210 that is switched using spin-orbit coupling. For clarity, Fig. Figure 8 is not to scale. The magnetic memory 200 is analogous to the magnetic memories 100, 100', 100" and 100"'. Accordingly, similar components have analogous designations. The magnetic memory 200 therefore has a magnetic contact 210 and an active SO layer 220, which are analogous to the magnetic contact 110 / 110' / 110" / 110"' and the active SO layer 120 / 120' / 120" / 120"'. The magnetic contact 210 has a data storage / free layer 212, a non-magnetic spacer layer 214, and a reference layer 216, which are analogous to the storage / free layer 112 / 112' / 112" / 112"', the non-magnetic spacer layer 114 / 114' / 114" / 114"', and the reference layer 116 / 116' / 116" / 116'". Therefore, the structure and function of components 210 and 220 are analogous to those described above for components 110 / 110' / 110" / 110"' and 120 / 120' / 120" / 120'" respectively.For example, the free layer 212 can have a slight axis in the plane or perpendicular to the plane and is used to store data. The reference layer 216 can also have its magnetic moments fixed in the plane or perpendicular to the plane. The magnetic contact 210 can be switched using spin-orbit coupling, either as a primary mechanism or to support another mechanism, such as a spin-transfer torque as described above.

[0054] In addition to the magnetic contact 210, the magnetic memory 200 has a selector 218 corresponding to each magnetic contact 210. In the embodiment shown, a memory cell has one magnetic contact 210 and one selector 218. The selector 218 is a transistor and can be coupled to a bit line. In the embodiment shown, a magnetic memory 200 can also have an optional spin-diffusion insertion layer 230. The optional spin-diffusion insertion layer 230 for some embodiments is a metal. In other embodiments, however, this layer can be a thin insulating material, for example, crystalline MgO or another oxide or insulating layer. The resistance area (RA) of such a layer should be small, for example, less than 2 ohm-µm. 2In other embodiments, the optional spin-diffusion insertion layer 230 can be a multilayer comprising two or more layers of different materials. The optical spin-diffusion insertion layer 230 can be used to decrease the contribution to the spin-orbit field given by the equation in paragraph

[045] and / or to increase the contribution to the spin-orbit field given by an equation in paragraph

[041] , if it is desired that this be the primary contribution used in switching the magnetic contact 210. The optional spin-diffusion insertion layer 230 can also be used to provide an improved nucleation layer for the free layer 212 and / or to reduce free layer damping, which may be associated with proximity to the active SO layer 220.

[0055] Although only one magnetic contact 210 in Fig. As shown in Figure 8, the active SO layer extends over several magnetic contacts. Therefore, the active SO layer 220 can also function as a word line. Furthermore, the active SO layer 220 is shown to have a substantially constant thickness (dimension in the z-direction) and width (dimension in the y-direction). In some embodiments, the thickness and / or width of the active SO layer is reduced, at least beneath the magnetic contact 210. In such embodiments, the spin-orbit current density is increased in the region of the magnetic contact 210. Therefore, switching using spin-orbit coupling can be improved.

[0056] The magnetic memory 200 shares the advantages of the magnetic memories 100, 100', 100'', and 100'''. Since the spin-orbit torque is used when switching the magnetic moment 213 of the free layer 212, the performance of the memory 200 can be improved. Because the SO current for the active SO layer 220 is in the plane, the current density J can be SO be large. Therefore, a faster stage of the magnetic contact 210 can be achieved more easily. Furthermore, the magnetic contact 210 can be a single magnetic contact instead of a dual magnetic contact, which has two reference layers. Therefore, there are issues such as magnetoresistance cancellation and issues with the growth of the barrier layers for a dual contact. Therefore, the performance of the memory 200 can be improved.

[0057] Fig. Figure 9 represents an exemplary embodiment of a magnetic storage device 200' which employs a magnetic contact 210' that is switched using spin-orbit coupling. For clarity, Fig. Figure 9 is not to scale. The magnetic memory 200' is analogous to the magnetic memories 200, 100, 100', 100'', 100'''. Accordingly, similar components have analogous designations. The magnetic memory 200' therefore has a magnetic contact 210' and an active SO layer 220', which are analogous to the magnetic contact 210 / 110 / 110' / 110'' / 110''' and the active SO layer 220 / 120 / 120' / 120'' / 120'''. The magnetic contact 210' has a data storage / free layer 212', a non-magnetic spacer layer 214' and a reference layer 216', which are analogous to the storage / free layer 212 / 112 / 112' / 112" / 112"', the non-magnetic spacer layer 214 / 114 / 114' / 114" / 114"', and the reference layer 216 / 116 / 116' / 116" / 116"'.Accordingly, the structure and function of components 210' and 220' are analogous to those described above for components 210 / 110 / 110' / 110" / 110"' and 220 / 120 / 120' / 120" / 120'". For example, the free layer 212' can have a slight axis in the plane or perpendicular to the plane and is used to store data. The reference layer 216' can likewise have its magnetic moment fixed in the plane or perpendicular to the plane. The magnetic contact 210' can be switched using spin-orbit coupling or spin-orbit interaction, either as a primary mechanism or to support another mechanism, such as a spin-transfer torque, as described above. The magnetic storage 200' can also have an optional spin diffusion insertion layer 230' analogous to the optional spin diffusion insertion layer 230.For simplicity, the SO-field 222' is shown in the y-direction. The SO-field 222' can be in another direction, including but not limited to perpendicular to the plane (for example, in the positive or negative z-direction).

[0058] The magnetic memory 200' also includes a word line 240. The word line 240 extends over several magnetic contacts 210' and thus several memory cells. The active SO layer 220' is electrically coupled to the word line but is located within the area of ​​a single magnetic contact 210'. Thus, in the embodiment shown, each active SO layer 220' corresponds to a magnetic contact 210'. In the embodiment shown, the active SO layer 220' extends over the word line 240. In other embodiments, however, the top surface of the active SO layer 220' can be substantially flush with the top surface of the word line 240, if positioned differently. In the embodiment shown, the bottom surface of the active SO layer 220' is located within the word line 240.Accordingly, the active SO layer 220' can be located in a recess within the word line 240. In other embodiments, however, the base of the active SO layer 220' can be located elsewhere. Alternatively, the active SO layer 220' can have a thickness less than or equal to that of the word line 240 and be located in an opening in the word line. In such embodiments, the current density through the active SO layer 220' can be greater than in the surrounding word line 240. The active SO layer 220' is also shown extending to the edges of the magnetic contact 210'. In other embodiments, however, the active SO layer 220' can extend further than the magnetic contact 210' in the xy-plane.

[0059] The magnetic memory 200 shares the advantages of the magnetic memories 200, 100, 100', 100" and 100"'. Since the spin-orbit torque is used when switching the magnetic moment 213' of the free layer 212', the performance of the memory 200' can be improved. Since the SO current for the active SO layer 220 is in the plane, the current density J can be SO be large. Accordingly, a faster stage of the magnetic contact 210' can be achieved more easily. Furthermore, the magnetic contact 210' can be a single magnetic contact instead of a dual magnetic contact, which has two reference layers. Accordingly, there are issues such as magnetoresistance cancellation and issues with the growth of the barrier layers for a dual contact. Accordingly, the performance of the memory 200' can be improved.

[0060] Fig. Figure 10 represents an exemplary embodiment of a magnetic storage device 200" which employs a magnetic contact 210" that is switched using spin-orbit coupling. For clarity, Fig. Figure 10 is not to scale. The magnetic memory 200" is analogous to the magnetic memories 200, 200', 100, 100', 100", 100"'. Accordingly, similar components have analogous designations. The magnetic memory 200" therefore has a magnetic contact 210" and an active SO layer 220", which are analogous to the magnetic contact 210 / 210' / 110 / 110' / 110" / 110"' and the active SO layer 220 / 220' / 120 / 120' / 120" / 120"'. The magnetic contact 210" has a data storage / free layer 212", a non-magnetic spacer layer 214" and a reference layer 216'', which are analogous to the storage / free layer 212 / 212' / 112 / 112' / 112'' / 112''', the non-magnetic spacer layer 214 / 214'114 / 114' / 114'' / 114''' and the reference layer 216 / 216' / 116 / 116' / 116'' / 116'''.Accordingly, the structure and function of components 210'' and 220'' are analogous to those described above for components 210 / 210' / 110 / 110' / 110'' / 110''' and 220 / 220' / 120 / 120' / 120'' / 120'''. For example, the free layer 212'' can have a slight axis in the plane or perpendicular to the plane, and it is used to store data. The reference layer 216'' can likewise have its magnetic moment fixed in the plane or perpendicular to the plane. The magnetic contact 210'' can be switched using spin-orbit coupling, either as a primary mechanism or to support another mechanism, such as a spin-transfer torque, as described above. The magnetic storage 200'' can also have an optional spin diffusion insertion layer 230'' analogous to the optional spin diffusion insertion layer 230 / 230'.For simplicity, the SO-field 222'' is shown in the y-direction. However, the SO-field 222'' can be in another direction, including but not limited to perpendicular to the plane (for example, in the positive or negative z-direction).

[0061] The magnetic memory 202' also has a word line 240' analogous to the word line 240. The word line 240' extends over several magnetic contacts 210' and thus over several memory cells. The active SO layer 220'' is electrically coupled to the word line, but it is located in the area of ​​a single magnetic contact 210''. Thus, in the embodiment shown, each active SO layer 220'' corresponds to a magnetic contact 210''. In the embodiment shown, the active SO layer 220'' extends above and below the word line 240'. In the embodiment shown, the active layer 220' is located in an opening within the word line 240'. In other embodiments, however, the top and / or bottom of the active SO layer 220'' may be positioned differently. The active SO layer 220' is also shown to extend to the edges of the magnetic contact 210''.In other embodiments, however, the active SO layer 220" can extend further than the magnetic contact 210" in the xy-plane.

[0062] The 200" magnetic memory shares the advantages of the 200, 200', 100, 100', 100" and 100"' magnetic memories. Since the spin-orbit torque is used when switching the magnetic moment 213" of the free layer 212", the performance of the 200" memory can be improved. Because the SO current for the active SO layer 220" is in the plane, the current density J can be SOIt should be large. Therefore, a faster magnetic contact speed of 210" can be achieved more easily. Furthermore, the magnetic contact 210" can be a single magnetic contact instead of a dual magnetic contact with two reference layers. Therefore, there are issues such as magnetoresistance cancellation and issues with the growth of the barrier layers for a dual contact. Therefore, the performance of the 200" memory can be improved.

[0063] Fig. Figure 11 represents an exemplary embodiment of a magnetic storage device 200"' which employs a magnetic contact 210"' that is switched using spin-orbit coupling. For clarity, Fig. Figure 11 is not to scale. The magnetic storage device 200'' is analogous to the magnetic storage devices 200, 200', 200", 100, 100', 100", 100''. Accordingly, similar components have analogous designations. The magnetic storage 200"' therefore has a magnetic contact 210"' and an active SO layer 220"', which are analogous to the magnetic contact 210 / 210' / 210" / 110 / 110' / 110" / 110"' and the active SO layer 220 / 220' / 220" / 120 / 120' / 120" / 120"'. The magnetic contact 210"' has a data storage / free layer 212"', a non-magnetic spacer layer 214"' and a reference layer 216"', which are analogous to the storage / free layer 212 / 212' / 212" / 112 / 112' / 112" / 112"' and the non-magnetic spacer layer. 214 / 214' / 214" / 114 / 114' / 114" / 114"' and the reference layer 216 / 216' / 216" / 116 / 116' / 116" / 116"'.Accordingly, the structure and function of components 210"' and 220"' are analogous to those described above for components 210 / 210' / 210" / 110 / 110' / 110" / 110"' and 220 / 220' / 220" / 120 / 120' / 120" / 120"'. For example, the free layer 212''' can have an easy axis in the plane or perpendicular to the plane, and it is used to store data. The reference layer 216''' can likewise have its magnetic moment fixed in the plane or perpendicular to the plane. The magnetic contact 210''' can be switched using spin-orbit coupling, either as a primary mechanism or to support another mechanism, such as a spin-transfer torque, as described above. The magnetic storage 200''' can also have an optional spin diffusion insertion layer 230''' analogous to the optional spin diffusion insertion layer 230 / 230' / 230''.For simplicity, the SO field 222''' is shown in the y-direction. However, the SO field 222''' can be in another direction, including but not limited to perpendicular to the plane (for example, in the positive or negative z-direction).

[0064] The magnetic memory 200''' also has a word line 240'' analogous to the word line 240 / 240'. The word line 240'' extends over several magnetic contacts 210'' and thus several memory cells. The active SO layer 220'' is electrically coupled to the word line but is localized or placed within the region of a single magnetic contact 210'''. In the embodiment shown, the active SO layer 220''' is adjacent to the magnetic contact 210'''. The active SO layer 220''' is not directly beneath the free layer 212'''. Instead, another section of the word line 240'' is beneath the magnetic contact 210'''. The active SO layer 220''' can be located at some distance from the magnetic contact 210'''. This separation should not be very large, typically less than the width of the MTJ. However, for some other embodiments it can be larger than this, up to 100 nm.

[0065] The magnetic memory 200''' shares the advantages of the magnetic memories 200, 200', 200'', 100, 100', 100'', and 100'''. Since the spin-orbit torque is used when switching the magnetic moment 213''' of the free layer 212''', the performance of the memory 200''' can be improved. Since the SO current for the active SO layer 220''' is in the plane, the current density J can be SO be large. Therefore, a faster magnetic contact level of 210''' can be achieved more easily. Furthermore, the magnetic contact 210''' can be a single magnetic contact instead of a dual magnetic contact, which has two reference layers. Therefore, there are issues such as magnetoresistance cancellation and issues with the growth of the barrier layers for a dual contact. Therefore, the performance of the memory 200''' can be improved.

[0066] Fig. Figure 12 represents an exemplary embodiment of a magnetic storage device 200'''' which employs a magnetic contact 210'''' that is switched using spin-orbit coupling. For clarity, Fig. Figure 12 is not to scale. The magnetic memory 200'''' is analogous to the magnetic memories 200, 200', 200'', 200''', 100, 100', 100'', 100'''. Accordingly, similar components have analogous designations. The magnetic memory 200''' therefore has a magnetic contact 210'''' and an active SO layer 220''', which are analogous to the magnetic contact 210 / 210' / 210'' / 210''' / 110 / 110' / 110'' / 110''' and the active SO layer 220 / 220' / 220'' / 220''' / 120 / 120' / 120'''. The magnetic contact 210'''' has a data storage / free layer 212'''', a non-magnetic spacer layer 214'''' and a reference layer 216'''', which are analogous to the storage / free layer 212 / 212' / 212'' / 212''' / 112 / 112' / 112'' / 112''', the non-magnetic spacer layer 214 / 214' / 214'' / 214''' / 114 / 114' / 114'' / 114''' and the reference layer 216 / 216' / 216'' / 216'''' / 116 / 116' / 116'' / 116''''.Accordingly, the structure and function of components 210'''' and 220'''' are analogous to those described above for components 210 / 210' / 210'' / 210'''' / 110 / 110' / 110'' / 110''' and 220 / 220' / 220'''' / 220''' / 120 / 120' / 120'' / 120'''. For example, the free layer 212'''' can have a slight axis in the plane or perpendicular to the plane, and it is used to store data. The reference layer 216'''' can likewise have its magnetic moment fixed in the plane or perpendicular to the plane. The magnetic contact 210'''' can be switched using spin-orbit coupling, either as a primary mechanism or to support another mechanism, such as a spin-transfer torque, as described above. The magnetic storage 200'''' can also have an optional spin diffusion insertion layer 230'''' analogous to the optional spin diffusion insertion layer 230 / 230' / 230'' / 230'''.For simplicity, the SO field 222'''' is shown in the y-direction. However, the SO field 222'''' can be in another direction, including but not limited to perpendicular to the plane (for example, in the positive or negative z-direction).

[0067] The magnetic storage device 200''' also includes a transistor 245, which can be part of a conductive line. The transistor has a source 247 and a drain 248, which are separated by the active SO layer 220''''. The transistor 245 also has a gate (not shown), which can be offset from the magnetic contact 210'''' in the y-direction. Thus, the active SO layer 220''' can be part of a channel through which the in-plane spin orbit current flows.

[0068] The magnetic memory 200''' shares the advantages of the magnetic memories 200, 200', 200'', 200'''', 100, 100', 100'', and 100''''. Since the spin-orbit torque is used when switching the magnetic moment 213'''' of the free layer 212'''', the performance of the memory 200'''' can be improved. Since the SO current for the active SO layer 220'''' is in the plane, the current density J can be SO be large. Therefore, a faster magnetic contact stage of 210'''' can be achieved more easily. Furthermore, the magnetic contact 210'''' can be a single magnetic contact instead of a dual magnetic contact, which has two reference layers. Therefore, there are issues such as magnetoresistance cancellation and issues with the growth of the barrier layers for a dual contact. Therefore, the performance of the memory 200'''' can be improved.

[0069] Fig. Figure 13 presents an exemplary embodiment of a magnetic storage device 250 which employs a magnetic contact 260 that is switched using a feature that mimics spin-orbit coupling. For clarity, Fig. Figure 13 is not to scale. The magnetic memory 250 is analogous to the magnetic memories 200, 200', 200'', 200'''', 200'''', 100, 100', 100'', 100'''. Accordingly, similar components have analogous designations. The magnetic memory 250 therefore has a magnetic contact 260 and a structure 270, which are analogous to the magnetic contact 210 / 210' / 210'' / 210''' / 210'''' / 110 / 110' / 110'' / 110''' and the active SO layer 220 / 220' / 220'' / 220'' / 220'''' / 120 / 120' / 120'' / 120'''. The magnetic contact 260 has a data storage / free layer 262, a non-magnetic spacer layer 264 and a reference layer 266, which are analogous to the storage / free layer 212 / 212' / 212'' / 212'''' / 212'''' / 112 / 112' / 112'' / 112'''', the non-magnetic spacer layer 214 / 214' / 214' / 214''' / 214'''' / 114 / 114' / 114'' / 114'''' and the reference layer 216 / 216' / 216'' / 216'''' / 216'''' / 116 / 116' / 116'' / 116''''.Accordingly, the structure and function of components 260 and 270 are analogous to those described above for components 210 / 210' / 210'' / 210'''' / 210'''' / 110 / 110' / 110'' / 110''' and 220 / 220' / 220' / 220'''' / 220'''' / 120 / 120' / 120'' / 120'''. For example, the free layer 262 can have a slight axis in the plane or perpendicular to the plane and is used to store data. The reference layer 266 can also have its magnetic moment fixed in the plane or perpendicular to the plane. The magnetic contact 260 can be switched using polarized charge carriers analogous to spin-orbit coupling, either as a primary mechanism or to support another mechanism, such as a spin-transfer torque, as described above.The magnetic storage 250 can also have an optional spin diffusion insertion layer 280 analogous to the optional spin diffusion insertion layer 230 / 230' / 230'' / 230''' / 230''''.

[0070] In the context of the present application, the magnetic memory 250 is considered to employ spin-orbit coupling when switching the magnetic contacts 260, since a structure 270 analogous to the active SO layer is used. More precisely, the structure 270, which is external to the magnetic contacts 260, provides a spin-polarized in-plane current, which is used when switching the magnetic contact 260. Thus, the switching mechanism for the memory 250 imitates spin-orbit coupling.

[0071] In the magnetic storage device 250, the structure 270 is formed analogously to the active SO layer from a combination of a highly conductive word line 276 and at least one spin-polarized injector 274. In the embodiment described in Fig. As shown in Figure 13, only a single spin-polarized current injector 224 is used. In other embodiments, however, several spin-polarized injectors can be used. For example, two injectors with opposite spin polarities can be used. Alternatively, a single polarized spin injector 274 can be used, but with the direction of the current reversed. The spin-polarized current injector 274 polarizes the spins of the charge carriers for a current driven through the spin-polarized current injector 274. For example, the spin-polarized current injector 274 can be a magnetic layer. Furthermore, a single spin-polarized injector 274 is desirable to provide polarized spins for several magnetic contacts 260. Accordingly, the high-conductivity word line 276 is at least one conductive layer with a long spin diffusion length.For example, the spin diffusion length is at least 100 nanometers in some embodiments. In some such embodiments, the spin diffusion length is at least 1 micron. For example, in one embodiment, the high-conductivity word line 276 can be a graphene line. The long spin diffusion length is desirable so that the spin-polarized charge carriers from the injector 274 can traverse the word line 276 and reach at least one magnetic contact 260 without undergoing significant scattering that would destroy the spin information of the charge carrier.

[0072] Since the current is polarized by the injector 274 and acquires its spin information as it moves through the high-conductivity word line 276, the polarized current acts in a manner similar to the spin polarization described above for the spin Hall and Rashba effects. Therefore, the combination of the injector 274 and the high-conductivity word line 276 functions analogously to the active SO layers 220 / 220' / 220'' / 220''' / 220'''' / 120 / 120' / 120'' / 120'''. In other words, the spin-polarized current can provide a field and torque analogous to the spin-orbit field and torque. Using the spin-polarized current either as a primary switching mechanism or to assist in switching, the magnetic contacts 260 can be written or described in an analogous manner as described above.

[0073] The magnetic memory 250 shares the advantages of the magnetic memories 200, 200', 200", 200'', 200''", 100, 100', 100" and 100''. Since the spin-orbit torque is used when switching the magnetic moment of the free layer, the performance of the memory 250 can be improved. Because the SO current for the active SO layer 270 is in the plane, the current density J can be SO be large. Therefore, a faster speed setting for magnetic contact 260 can be achieved more easily. Furthermore, magnetic contact 260 can be a single magnetic contact instead of a dual magnetic contact with two reference layers. Therefore, there are issues such as magnetoresistance cancellation and issues with the growth of the barrier layers for a dual contact. Therefore, the performance of memory 250 can be improved.

[0074] Accordingly, memories 200, 200', 200", 200"', 200"" and 250 each represent different configurations of the active SO layer 220, 220', 220", 220"', 220"" and 270. Regarding memories 100, 100', 100" and 100"', the magnetic contacts 210, 210', 210", 210"' and 260 can utilize spin-orbit torque as a primary switching mechanism or to assist the primary switching mechanism. When a spin-orbit torque is used without more than one primary switching mechanism, any magnetic contact 110, 110', 110", 110"', 210, 210', 210", 210"', 210"" and 260 along the active SO layer or word line containing the active SO layer can be switched. Therefore, a mechanism for selecting the magnetic contact to be written to is desirable.

[0075] Fig. Figure 14 represents an exemplary embodiment of a magnetic storage device 300, which uses magnetic contacts 310 that are primarily switched using spin-orbit coupling. For clarity, Fig. Figure 14 is not to scale. The magnetic memory 300 is analogous to the magnetic memories 100, 100', 100", 100"', 200, 200', 200", 200"', 200"" and 250. Accordingly, similar components have analogous designations. The magnetic memory 300 therefore has magnetic contacts 310, selectors 318 and an active SO layer 320, which are analogous to the magnetic contacts, selectors and active SO layers described above. Although not shown, the magnetic contact 310 has a data storage / free layer, a non-magnetic spacer layer and a reference layer, which are analogous to those described above. Accordingly, the structure and function of components 310 and 320 are analogous to those described above. Although the active SO layer 320 is shown as a word line, other configurations may be used in other embodiments.Optional spin-diffusion insertion layers 330 are also shown. These layers 330 are analogous to the optional spin-diffusion insertion layers 230, 230', 230", 230'', 230"" and / or 280. The free layers of the magnetic contacts 310 can each have a slight axis in the plane or perpendicular to the plane.

[0076] In memory 300, spin-orbit coupling switching is supported by a spin-transfer torque. Specifically, the active SO layer 320 is configured such that a desired combination of spin-orbit torque H SO and the spin-transfer torque is sufficient to switch the magnetic contact. For example, in the embodiment shown, the first spin-transfer selection current J generates STT-Sel1 an STT torque with the effective STT field H1 in the same direction as the spin-orbit field H SO It should be noted that although H1 and H SOBoth are shown in the xy-plane; in another embodiment, fields H1 and H SO in other directions, including perpendicular to the plane. Therefore, this magnetic contact is influenced by H SO and H1 switched. The spin transfer selection current J STT-Sel2 However, it is driven in the opposite direction. Therefore, the spin-transfer torque with the field H2 is in the opposite direction to the spin-orbit field H. SO The combined action of H SO The negative H2 is insufficient to switch the magnetic contact. Therefore, magnetic contact 310 is not switched, even if the spin-orbit torque H SOThe spin-transfer selection current alone is sufficient to program the magnetic contact 310. In other embodiments, the selection can be performed in a different manner. For example, in some embodiments, the spin-transfer selection current is driven only by magnetic contacts 310 that are to be programmed. In such embodiments, the spin-orbit torque is not sufficient to program the magnetic contact 310 without a spin-transfer torque in the same direction. In other embodiments, the spin-transfer selection current is driven only by magnetic contacts that are not to be programmed. In such embodiments, the spin-orbit torque is sufficient to program the magnetic contact 310 by itself. However, the combination of the spin-orbit torque and a spin-transfer torque in the opposite direction is not sufficient to program the magnetic contact.Accordingly, the magnetic memory 300 uses a spin transfer torque to select the magnetic contact 310 to be described, and uses a spin orbit torque as a primary switching mechanism.

[0077] The magnetic memory 300 shares the advantages of the magnetic memories 100, 100', 100", 100"', 200, 200', 200", 200"', 200"" and / or 250. Since the spin-orbit torque is used when switching the magnetic moment of the free layer, the performance of the memory 300 can be improved. Furthermore, the desired magnetic contact 310, which is programmable, can be selected using the spin-transfer torque. Therefore, the performance of the memory 300 can be improved.

[0078] Fig. Figure 15 represents an exemplary embodiment of a magnetic storage device 300' which uses magnetic contacts 310' that are primarily switched using spin-orbit coupling. For clarity, Fig. Figure 15 is not to scale. The magnetic memory 300' is analogous to the magnetic memories 100, 100', 100", 100"', 200, 200', 200", 200"', 200"", 250, and 300. Accordingly, similar components have analogous designations. The magnetic memory 300' therefore comprises magnetic contacts 310', selectors 318', and an optional spin-diffusion insertion layer 330' and an active SO layer 320', which are analogous to the magnetic contacts, selectors, spin-diffusion insertion layers, and active SO layers described previously. Although not shown, the magnetic contact 310' comprises a data storage / free layer, a non-magnetic spacer layer, and a reference layer, which are analogous to those described previously. Accordingly, the structure and function of components 310' and 320' are analogous to those described above.Although the active SO layer 320' is shown as a word line, other configurations may be used in other embodiments. The free layers of the magnetic contacts 310' may each have an slight axis in the plane or perpendicular to the plane.

[0079] In the memory 300', spin-orbit coupling switching is assisted by heat. In the embodiment shown, heat is introduced into the desired magnetic contact 310 by driving a heating current J. Heat generated by the magnetic contact. For the magnetic contact, which is heated, or has been heated, the anisotropic field is on H k1 It has been reduced. This anisotropy field is sufficiently small that the spin-orbit field H SOexerts a sufficient torque to switch the magnetic contact 310'. In contrast, magnetic contacts 310, which are not to be switched, are not heated and therefore have a higher anisotropic field of H. k2 The spin-orbit torque H SO is insufficient to switch the magnetic moment of the free layer for the unheated magnetic contacts 310'. Therefore, the magnetic memory 300' uses heating of the magnetic contacts 310 to select the magnetic contact 310 to be written and uses a spin-orbit torque as a primary switching mechanism. It should be noted that although H k1 , H k2 and H SO Both are shown in the xy-plane; in another embodiment, the fields H k1 , H k2 and H SO in another direction, including perpendicular to the plane.

[0080] The 300' magnetic memory shares the advantages of the 100, 100', 100", 100'', 200, 200', 200", 200', 200''", 250, and / or 300 magnetic memories. Since the spin-orbit torque is used when switching the magnetic moment of the free layer, the performance of the 300 memory can be improved. Furthermore, the desired magnetic contact 310, which is programmable, can be selected using the spin-transfer torque. Therefore, the performance of the 300' memory can be improved.

[0081] Fig. Figure 16 represents an exemplary embodiment of a magnetic storage device 300'' which uses magnetic contacts 310'' that are primarily switched using spin-orbit coupling. For clarity, Fig. Figure 16 is not to scale. The 300'' magnetic memory is analogous to the 100, 100', 100'', 100''', 200, 200', 200'', 200''', 200''', 250, 300, and 300' magnetic memories. Accordingly, similar components have analogous designations. The 300'' magnetic memory therefore comprises magnetic contacts 310'', selectors 318'', and an optional spin-diffusion insertion layer 330'' and an active SO layer 320', which are analogous to the magnetic contacts, selectors, spin-diffusion insertion layers, and active SO layers described previously. Although not shown, the magnetic contact 310' has a data storage / free layer, a non-magnetic spacer layer, and a reference layer, which are analogous to those described previously. Therefore, the structure and function of components 310'' and 320'' are analogous to those described above.Although the active SO layer 320'' is shown as a word line, other configurations may be used in other embodiments. The free layers of the magnetic contacts 310' may each have an slight axis in the plane or perpendicular to the plane. It should be noted that although H. k1 , H k2 and H SO Both are shown in the xy-plane; in another embodiment, the fields H k1 , H k2 and H SO in another direction, including perpendicular to the plane.

[0082] In the memory 300'', spin-orbit coupling switching is supported by a voltage-controlled anisotropy. This can be achieved by using a non-magnetic barrier layer in the magnetic contact 310', which has a sufficiently large dielectric constant and a high RA. The right-angle magnetic anisotropy can be sensitive to the voltage applied across the contact. In the illustrated embodiment, a control voltage V is applied. Control1 applied via a magnetic contact 310". For a magnetic contact 310", which has a slight axis in the plane, the control voltage increases the right-angle magnetic anisotropy to H k1 The increase in anisotropy perpendicular to the light axis can allow the magnetic contact 310 to be switched. The magnetic contacts 310, which cannot be switched, have a different voltage V. Control2, which can be 0, is applied. As a result, such magnetic contacts 310"' have a reduced right-angle anisotropic field of H k2 Such magnetic contacts 310" cannot switch. In other embodiments, the magnetic contacts can have their light axes perpendicular to the plane. In such embodiments, applying the control voltage V results in Control1 This still leads to an increase in the perpendicular anisotropy. However, the magnetic contact will not switch because the anisotropy along the light axis has increased. In contrast, applying the control voltage V reduces this. Control2 the relative right-angled anisotropy. As a result, such a magnetic contact 310"' has a lower anisotropic field of H k2 The spin-orbit torque H SOThe magnetic moment of the free layer switches the lower magnetic contacts 310" of right-angle anisotropy. Accordingly, the magnetic memory 300" uses a voltage-controlled anisotropy of the magnetic contact 310 to select the magnetic contact 310 to be written to, and it uses a spin-orbit torque as a primary switching mechanism.

[0083] The 300" magnetic memory shares the advantages of the 100, 100', 100", 100'', 200, 200', 200", 200'', 200'', 300, and / or 300' magnetic memories. Since the spin-orbit torque is used when switching the magnetic moment of the free layer, the performance of the 300" memory can be improved. Furthermore, the selected magnetic contact 310", which is programmable, can be chosen using voltage-controlled anisotropies. Therefore, the performance of the 300' memory can be improved.

[0084] Fig. Figure 17 represents an exemplary embodiment of a magnetic storage device 300"' which uses magnetic contacts 310"' that are primarily switched using spin-orbit coupling. For clarity, Fig. Figure 17 is not to scale. The 300"' magnetic storage device is analogous to the 100, 100', 100", 100"', 200, 200', 200", 200"', 200"", 250, 300, 300' and 300". Accordingly, similar components have analogous designations. The magnetic storage 300"' therefore comprises magnetic contacts 310"', selectors 318"', an optional spin-diffusion insertion layer 330"', and an active SO layer 320"', which are analogous to the magnetic contacts, selectors, spin-diffusion insertion layers, and active SO layers described above. Although not shown, the magnetic contact 310"' comprises a data storage / free layer, a non-magnetic spacer layer, and a reference layer, which are analogous to those described above. Thus, the structure and function of components 310"' and 320"' are analogous to those described above.Although the active SO layer 320" is shown as a word line, other configurations may be used in other embodiments. The free layers of the magnetic contacts 310"' may each have an slight axis in the plane or perpendicular to the plane. It should be noted that although H. SO1 and H SO2 Both are shown in the xy-plane; in another embodiment, the fields H SO1 and H SO2 in another direction, including perpendicular to the plane.

[0085] In the memory 300"', spin-orbit coupling switching is supported by resistor control. In the illustrated embodiment, the resistance of resistor 335 is controlled by resistor selection transistors 336. Thus, the resistors 335 are variable resistance elements. Resistor R1 has a high resistance relative to the resistance of the active SO layer 320"'. Therefore, the current in the active SO layer 320" is not conducted through resistor 335. As such, the spin-orbit torque, which is determined by H SO1 The generated current is still sufficient to switch the magnetic element 310'''. For the resistance R2, which is smaller relative to the active SO layer 320''', the spin-orbit current J is... SO through the resistor R2. The accumulation of charge carriers on the upper surface of layer 320"' is reduced. The spin-orbit field H SO2is also reduced. Therefore, the spin-orbit field generated above R2 is insufficient to write to magnetic contact 310'''. Therefore, the magnetic memory 300''' uses resistance changes for the magnetic contacts 310 to select the magnetic contact 310 to be written to, and uses a spin-orbit torque as a primary switching mechanism.

[0086] The 300''' magnetic memory shares the advantages of the 100, 100', 100'', 100''', 200, 200', 200''', 200'''', 250, 300, 300', and 300'' magnetic memories. Since the spin-orbit torque is used when switching the magnetic moment of the free layer, the performance of the 300''' memory can be improved. Furthermore, the desired magnetic contact 310''', which is programmable, can be selected using a spin-transfer torque. Therefore, the performance of the 300''' memory can be improved.

[0087] Fig. Figure 18 represents an exemplary embodiment of a magnetic storage device 300'''' which uses magnetic contacts 310'''' that are primarily switched using spin-orbit coupling. For clarity, Fig. Figure 18 is not to scale. The magnetic memory 300'''' is analogous to the magnetic memories 100, 100', 100'', 100'''', 200, 200', 200'''', 200'''', 250, 300, 300', 300'', and 300'''. Accordingly, similar components have analogous designations. The magnetic memory 300'''' therefore has magnetic contacts 310'''', selection devices 318'''', and an optional spin-diffusion insertion layer 330'''' and an active SO layer 320'''', which are analogous to the magnetic contacts, selection devices, spin-diffusion insertion layers, and active SO layers described previously. Although not shown, the magnetic contact 310'''' has a data storage / free layer, a non-magnetic spacer layer, and a reference layer, which are analogous to those described previously. Therefore, the structure and function of components 310'''' and 320'''' are analogous to those described above.Although the active SO layer 320''' is shown as a word line, other configurations may be used in other embodiments. The free layers of the magnetic contacts 310''' may each have an slight axis in the plane or perpendicular to the plane. It should be noted that although H. SO1 and H SO2 Both are shown in the xy-plane; in another embodiment, the fields H SO1 and H SO2 in another direction, including perpendicular to the plane.

[0088] In memory 300'''', spin-orbit coupling switching is supported by heating the active SO layer 320'''' using heaters 340. The heaters 340 are controlled by heater selection transistors 342. When the heating element, such as heater 1, is inactive, the active SO layer 320'''' can generate the desired spin-orbit field H. SO1to generate switching of the magnetic contact 310''''. However, the heater 2 can be operated. The active SO layer 320 is heated, which increases the relaxation of the SO-induced spin clusters and thus the spin-orbit field H. SO2 reduced. The generated spin-orbit field is insufficient to write to the magnetic contact 310''''. Therefore, the magnetic memory 300'''' uses heating of the active SO layer 320'''' to select the magnetic contact 310'''' to be written to, and uses a spin-orbit torque as a primary switching mechanism.

[0089] The 300'''' magnetic memory shares the advantages of the 100, 100', 100'', 100'''', 200, 200', 200'''', 200'''', 250, 300, 300', 300'', and 300'''' magnetic memories. Since the spin-orbit torque is used when switching the magnetic moment of the free layer, the performance of the 300'''' memory can be improved. Furthermore, the desired magnetic contact 310''', which is programmable, can be selected using a spin-transfer torque. Therefore, the performance of the 300''' memory can be improved.

[0090] Fig. Figure 19 is a flowchart illustrating an exemplary embodiment of a method 400 for providing a magnetic storage device having a magnetic contact (or contacts) which is switched using spin-orbit coupling. For simplification, some steps may be omitted, combined, and / or nested. The method 400 is described in the context of the magnetic storage device 100. However, the method can also be used to provide other magnetic storage devices, including but not limited to the magnetic storage devices 100', 100", 100"', 200, 200', 200", 200"', 200"", 250, 300, 300', 300", 300"', and / or 300"".

[0091] The active SO layer 120 is provided via step 402. In some embodiments, step 402 includes the provision of a layer suitable for the spin Hall effect. In other embodiments, a layer suitable for the Rashba effect is provided. In still other embodiments, the active SO layer 120 may utilize a combination of the spin Hall and Rashba effects. Other spin-orbit coupling or spin-orbit interaction mechanisms may also be provided. Step 402 may also include the structuring of the active SO layer. A spin diffusion layer (not shown in the magnetic memory 100) is optionally provided via step 404. If provided, the spin diffusion layer is located between the active SO layer 120 and the magnetic contacts 110.

[0092] The magnetic contacts 110 are provided via step 406. In some embodiments, step 406 includes the provision of a free layer 112, a non-magnetic layer such as a tunnel barrier layer 114, and a reference layer 116. The fabrication of the magnetic memory 100 can then be completed. Accordingly, by using method 400, the advantages of one or more of the magnetic memories 100, 100', 100", 100"', 200, 200', 200", 200"', 200"", 250, 300, 300', 300"' and / or 300"" can be achieved.

[0093] Fig. Figure 20 is a flowchart which provides an exemplary embodiment of a method 450 for programming a magnetic contact (magnetic contacts) which are switched using spin-orbit coupling. Method 450 can be used with one or more of the following memory units: 100, 100', 100", 100"', 200, 200', 200", 200"', 200", 250, 300, 300', 300"', and / or 300"". For simplification, some steps may be omitted, combined, and / or nested. Method 450 is described in the context of magnetic memory unit 100. However, Method 450 can be used with other magnetic contacts, including but not limited to magnetic memory units 100, 100', 100", 100"', 200, 200', 200", 200"', 200", 250, 300, 300', 300"', and / or 100"". 300".

[0094] A spin-orbit write current is applied in the plane via step 452. The spin-orbit write current can be applied as a pulse. The duration and the rate of increase or amplitude of the pulse may be desired to be short, for example, no more than 0.1–3 nanoseconds for spin-orbit coupling-assisted switching. Other pulse durations may be used in other embodiments. In some embodiments, the pulse duration may be longer if spin-orbit coupling is the primary switching mechanism.

[0095] A spin-carry torque write current is optionally driven through the magnetic contact via step 454. Step 454 is performed when spin-orbit coupling is used to assist with spin-carry torque writing. If spin-orbit coupling is used as the primary write mechanism, then step 454 can be omitted. The current in step 454 can also be applied as a pulse, as described above (for example, regarding...). Fig.5) The current pulse applied in step 454 is desired to start after the pulse in step 452 has begun. The current pulse can also start during, before, or after the spin-orbit writing current pulse has ended. The spin-transfer writing current pulse is desired to begin no later than the time required for some precessions of the magnetic moment of the free layer after the end of the spin-orbit coupling writing pulse. Thus, the writing of the cells can be completed using steps 452 and 454.

[0096] Additionally, the magnetic contacts 110 to be written to can be selected via step 456. For example, a spin-transfer torque, heating of the magnetic contact 110, voltage control of the magnetic anisotropy, resistance control via the active SO layer 120, heating of the active SO layer 120, some combination of the above, and / or other mechanisms can be used to select the cells to be written to. Step 456 can also be performed at essentially the same time as step 452. Thus, the desired magnetic contact 110 can be programmed in the magnetic memory 100. It should be noted that the magnetic contacts 110 can be read by driving a read current through the magnetic contacts 110 and determining whether the magnetic contacts 110 are in a high-resistance or low-resistance state.

[0097] Accordingly, using method 450, the magnetic memory locations 100, 100', 100", 100"', 200, 200', 200", 200"', 200"", 250, 300, 300', 300", 300"' and / or 300"" can be programmed. Therefore, the advantages of the magnetic memory locations 100, 100', 100", 100"', 200, 200', 200", 200"', 200"", 250, 300, 300', 300", 300"' and / or 300"" can be achieved.

[0098] A method and a system for providing a magnetic contact and a memory, which is produced using the magnetic contact, has been described. Various combinations of features in the magnetic memories 100, 100', 100", 100"', 200, 200', 200", 200"', 200"", 250, 300, 300', 300", 300"' and / or 300"" can be combined.

Claims

[1] Magnetic storage (100, 100', 100'', 100''', 200, 200', 250, 300, 300', 300'', 300'''', 300''''), comprising the following: a plurality of magnetic contacts (110, 110', 110'', 110''', 210, 260, 310, 310', 310'', 310''', 310''''), wherein each of the plurality of magnetic contacts (110, 110', 110'', 110''', 210, 260, 310, 310', 310'', 310''', 310''') has a data storage layer (112, 112', 112'', 112''', 212, 212''') wherein the data storage layer (112, 112', 112'', 112''', 212) is magnetic; and at least one active spin-orbit coupling layer, active SO layer (120, 120', 120'', 120''', 220, 270, 320, 320', 320', 320'', 320''''), adjacent to the data storage layer (112, 112', 112'', 112''', 212,) of the magnetic contact (110, 110', 110'', 110''', 210, 260, 310, 310', 310'', 310''', 310'''), wherein the at least one active SO layer (120, 120', 120'', 120''', 220, 270, 320, 320', 320'', 320''', 320'''') is configured so that it exerts an SO torque on the data storage layer (112, 112', 112'', 112''', 212) due to a current,which is connected by the at least one active SO layer (120, 120', 120'', 120''', 220, 270, 320, 320', 320''', 320'''', 320'''') in a direction substantially perpendicular to a direction between the at least one active SO layer (120, 120', 120'', 120''', 220, 270, 320, 320', 320'', 320''', 320'''') and the data storage layer (112, 112', 112'', 112''', 212,) of a magnetic contact (110, 110', 110'', 110''', 210, 260, 310, 310', 310'', 310'''', 310'''') of the majority of magnetic contacts (110, 110', 110'', 110'''', 210, 260, 310, 310', 310'', 310''', 310''') nearest to the at least one active SO layer (120, 120', 120'', 120''', 220, 270, 320, 320', 320'', 320''', 320''''); Without the current, at least one active SO layer (120, 120', 120", 120"', 220, 270, 320, 320', 320", 320"', 320"") is also configured to exert no SO torque on the data storage layer (112, 112', 112", 112"', 212), where the data storage layer (112,112', 112", 112"', 212) is configured so that it can be switched using at least the SO torque, wherein at least one active SO layer (120, 120', 120", 120"', 220, 270, 320, 320', 320", 320"', 320"") extends over at least two of the plurality of magnetic contacts (110, 110', 110", 110"', 210, 260, 310, 310', 310", 310"', 310""). [2] Magnetic storage device (100, 100', 100", 100"', 200, 250, 300, 300', 300", 300"', 300"") according to claim 1, wherein each of the plurality of magnetic contacts (110, 110', 110", 110"', 210, 260, 310, 310', 310", 310"', 310"") further comprises a reference layer (116, 116', 116", 116"', 216, 266) and a non-magnetic spacer layer (114, 114', 114", 114"', 214, 264), wherein the non-magnetic spacer layer (114, 114', 114", 114"', 214, 264) is located between the data storage layer (112, 112', 112", 112"', 212) and the reference layer (116, 116', 116", 116"', 216, 266), where the data storage layer (112, 112', 112", 112"', 212) is a free layer (112, 112', 112", 112"', 212). [3] Magnetic storage device (100, 100', 100", 100"', 200, 250, 300, 300', 300", 300"', 300"") according to claim 1, further comprising: a spin-diffusion insertion layer (230, 280) for each of the at least one active SO layer (120, 120', 120", 120"', 220, 270, 320, 320', 320", 320"', 320""), wherein the spin-diffusion insertion layer (230, 280) is between the data storage layer (112, 112', 112", 112"', 212) and the at least one active SO layer (120, 120', 120", 120"', 220, 270, 320, 320', 320", 320"', 320""). [4] Magnetic storage (100, 100', 100", 100"', 200, 250, 300, 300', 300", 300"', 300"") according to claim 1, wherein the at least one active SO layer (120, 120', 120", 120"', 220, 270, 320, 320', 320", 320"', 320"") is selected from a first SO layer (120, 120', 120", 120"', 220, 270, 320, 320', 320", 320"', 320"") of X and a second SO layer (120, 120', 120", 120"', 220, 270, 320, 320', 320", 320'', 320"") of M doped with Y, wherein X comprises at least one of Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Cd, In, Sb, Te, Hf, Ta, amorphous β-Ta, W, Re, Os, Ir, Pt, Au, Hg, Tl, Pb, Bi, Po, and At, wherein M comprises at least one of Al, Ti, V, Cr, Mn, Cu, Zn, Ag, Hf, Ta, W, Re, Pt, Au, Hg, Pb, Si, Ga, GaMn, and GaAs, and wherein Y comprises at least one of V, Cr, Mn, Fe, Co, Ni, P, S, Zn, Ga, Ge, As, Se, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, In, Sb, Te, I, Lu, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg, Tl, Pb, Bi, Po, At, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, and Yb. [5] Magnetic storage device (100, 100', 100", 100"', 200, 250, 300, 300', 300", 300"', 300"") according to claim 1, wherein the at least one active SO layer (120, 120', 120", 120"', 220, 270, 320, 320', 320", 320"', 320"") comprises at least one of Cu, Zn, Ga, Ge, As, Se, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, In, Sn, Sb, Te, I, Lu, Hf, Ta, amorphous β-Ta, W, Re, Os, Ir, Pt, Au, Hg, Tl, Pb, Bi, Po, At, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, and Yb. [6] Magnetic storage (100, 100', 100", 100"', 200, 250, 300, 300', 300", 300"', 300"") according to claim 5, wherein the active SO layer (120, 120', 120", 120"', 220, 270, 320, 320', 320", 320"', 320"") is adjacent to the data storage layer (112, 112', 112", 112"', 212), wherein the data storage layer (112, 112', 112", 112"', 212) comprises at least one of Co, Fe, Ni, Mn, and wherein the magnetic contact (110, 110', 110" 110"', 210, 210',260, 310, 310', 310", 310"', 310"") has an insulating layer adjacent to the data storage layer (112, 112', 112", 112"', 212), wherein the insulating layer adjacent to the data storage layer (112, 112', 112", 112"', 212 has at least one of an aluminum oxide and one of a magnesium oxide. [7] Magnetic storage (100, 100', 100", 100"', 200, 250, 300, 300', 300", 300"', 300"") according to claim 1, wherein the at least one active SO layer (120, 120', 120", 120"', 220, 270, 320, 320', 320", 320"', 320"") is an active SO word line. [8] Magnetic storage device (100, 100', 100", 100"', 200, 250, 300, 300', 300", 300"', 300"") according to claim 1, further comprising: at least one word line, which corresponds to the majority of the magnetic contacts (110, 110', 110", 110"', 210, 260, 310, 310', 310", 310"', 310""), wherein the at least one active SO layer (120, 120', 120", 120"', 220, 270, 320, 320', 320", 320"', 320"") is located between the data storage layer (112, 112', 112", 112", 212) and the at least one word line. [9] Magnetic storage device (100, 100', 100'', 100''', 200, 250, 300, 300', 300'', 300'', 300'''') according to claim 8, wherein the at least one word line has at least one opening which corresponds to each of the at least one active SO layer (120, 120', 120'', 120'', 220, 270, 320, 320', 320'', 320'''', 320'''').

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