WO2019005034A1

WO2019005034A1 - In-plane tilt in perpendicular magnetic tunnel junction devices using an in-plane magnet layer

Info

Publication number: WO2019005034A1
Application number: PCT/US2017/039713
Authority: WO
Inventors: Charles C. Kuo; Juan G. ALZATE VINASCO; Mark L. Doczy; Kaan OGUZ; Kevin P. O'brien
Original assignee: Intel Corporation
Priority date: 2017-06-28
Filing date: 2017-06-28
Publication date: 2019-01-03

Abstract

Apparatuses including perpendicular magnetic tunnel junctions having free and fixed magnet layers with perpendicular magnetic anisotropy separated by a barrier layer and an in- plane magnet layer with in-plane magnetic anisotropy adjacent to the free magnet layer and opposite the fixed magnet layer, systems incorporating such apparatuses, and methods for forming them are discussed.

Description

IN-PLANE TILT IN PERPENDICULAR MAGNETIC TUNNEL JUNCTION DEVICES

USING AN IN-PLANE MAGNET LAYER

TECHNICAL FIELD

Embodiments of the invention generally relate to magnetic tunnel junction devices with reduced incubation time before spin torque transfer switching and more particularly relate to magnetic tunnel junctions having free and fixed magnet layers separated by a barrier layer and related devices and manufacturing techniques.

BACKGROUND

In some implementations, magnetic memory devices such as spin transfer torque memory (STTM) include a magnetic tunnel junction (MTJ) for switching and detecting the state of the memory. For example, the magnetic tunnel junction may include fixed and free magnets separated by a barrier layer such that the fixed and free magnets have perpendicular magnetic anisotropy. In the detection of the memory state, a magnetic tunnel junction resistance of the memory is established by the relative magnetization of the fixed and free magnets. When the magnetization directions are parallel, the magnetic tunnel junction resistance is in a low state and, when the magnetization directions are anti-parallel, the magnetic tunnel junction resistance is in a high state. The relative magnetization directions are provided or written to the memory by varying the magnetization direction of the free magnet while the magnetization direction of the fixed magnet remains, as the name implies, fixed. The magnetization direction of the free magnet is changed by passing a driving current polarized by the fixed magnet through the free magnet. The switching of the magnetization direction of the free magnet includes an incubation

(e.g., delay) time before spin transfer torque switching occurs with the applied drive current. Such a delay time may be disadvantageous as it slows write operations of the memory device. Furthermore, overcoming such delay times with increased drive current may disadvantageously increase the power usage of the memory. As such, existing techniques do not provide for magnetic tunnel junction devices or structures with low delay times and/or low drive currents. Such problems may become critical as devices such as memory devices having increased speed, reduced drive current, and low power consumption are needed in various applications. BRIEF DESCRIPTION OF THE DRAWINGS

The material described herein is illustrated by way of example and not by way of limitation in the accompanying figures. For simplicity and clarity of illustration, elements illustrated in the figures are not necessarily drawn to scale. For example, the dimensions of some elements may be exaggerated relative to other elements for clarity. Furthermore, where considered appropriate, reference labels have been repeated among the figures to indicate corresponding or analogous elements. In the figures:

FIG. 1A is an exploded isometric view of an example magnetic tunnel junction device structure; FIG. IB is a collapsed side view of the example magnetic tunnel junction device structure;

FIG. 2 illustrates an example state switching context for an magnetic tunnel junction device structure;

FIG. 3 illustrates an example multi-material free magnet layer;

FIG. 4A is an exploded isometric view of an example magnetic tunnel junction device structure;

FIG. 4B is a collapsed side view of the example magnetic tunnel junction device structure;

FIG. 5 is a flow diagram illustrating an example process for fabricating magnetic tunnel junction device structures;

FIGS. 6A, 6B, 6C, 6D are side views of example magnetic tunnel junction device structures as particular fabrication operations are performed;

FIG. 7 is a schematic of a non-volatile memory device including a magnetic tunnel junction device structure having an in-plane magnetic layer;

FIG. 8 illustrates an example cross-sectional die layout including example magnetic tunnel junction device structure; FIG. 9 illustrates a system in which a mobile computing platform and/or a data server machine employs a magnetic tunnel junction device having an in-plane magnet layer; and FIG. 10 is a functional block diagram of a computing device, all arranged in accordance with at least some implementations of the present disclosure.

DETAILED DESCRIPTION One or more embodiments or implementations are now described with reference to the enclosed figures. While specific configurations and arrangements are discussed, it should be understood that this is done for illustrative purposes only. Persons skilled in the relevant art will recognize that other configurations and arrangements may be employed without departing from the spirit and scope of the description. It will be apparent to those skilled in the relevant art that techniques and/or arrangements described herein may also be employed in a variety of other systems and applications other than what is described herein.

Reference is made in the following detailed description to the accompanying drawings, which form a part hereof, wherein like numerals may designate like parts throughout to indicate corresponding or analogous elements. It will be appreciated that for simplicity and/or clarity of illustration, elements illustrated in the figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity. Further, it is to be understood that other embodiments may be utilized and structural and/or logical changes may be made without departing from the scope of claimed subject matter. It should also be noted that directions and references, for example, up, down, top, bottom, over, under, and so on, may be used to facilitate the discussion of the drawings and embodiments and are not intended to restrict the application of claimed subject matter. Therefore, the following detailed description is not to be taken in a limiting sense and the scope of claimed subject matter defined by the appended claims and their equivalents.

In the following description, numerous details are set forth, however, it will be apparent to one skilled in the art, that the present invention may be practiced without these specific details. In some instances, well-known methods and devices are shown in block diagram form, rather than in detail, to avoid obscuring the present invention. Reference throughout this specification to "an embodiment" or "in one embodiment" means that a particular feature, structure, function, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. Thus, the appearances of the phrase "in an embodiment" in various places throughout this specification are not necessarily referring to the same embodiment of the invention. Furthermore, the particular features, structures, functions, or characteristics may be combined in any suitable manner in one or more embodiments. For example, a first embodiment may be combined with a second embodiment anywhere the two embodiments are not specified to be mutually exclusive.

The terms "coupled" and "connected," along with their derivatives, may be used herein to describe structural relationships between components. It should be understood that these terms are not intended as synonyms for each other. Rather, in particular embodiments, "connected" may be used to indicate that two or more elements are in direct physical or electrical contact with each other. "Coupled" may be used to indicated that two or more elements are in either direct or indirect (with other intervening elements between them) physical or electrical contact with each other, and/or that the two or more elements co-operate or interact with each other (e.g., as in a cause an effect relationship).

The terms "over," "under," "between," "on", and/or the like, as used herein refer to a relative position of one material layer or component with respect to other layers or components. For example, one layer disposed over or under another layer may be directly in contact with the other layer or may have one or more intervening layers. Moreover, one layer disposed between two layers may be directly in contact with the two layers or may have one or more intervening layers. In contrast, a first layer "on" a second layer is in direct contact with that second layer. Similarly, unless explicitly stated otherwise, one feature disposed between two features may be in direct contact with the adjacent features or may have one or more intervening features.

Furthermore, the terms "substantially," "close," "approximately," "near," and "about," generally refer to being within +/- 10% of a target value. The term layer as used herein may include a single material or multiple materials.

Magnetic tunnel junction apparatuses, devices, systems, computing platforms, and methods are described below related to magnetic tunnel junction devices having enhanced switching characteristics.

As described above, it may be advantageous to provide magnetic tunnel junction devices having reduced incubation (e.g., delay) times and/or reduced drive currents for switching the devices. Such magnetic tunnel junction devices may provide increased operation speeds and/or power savings. In an embodiment, a magnetic tunnel junction apparatus or device includes a magnetic tunnel junction having a fixed magnet layer and a free magnet layer separated by a barrier layer such that the fixed and free magnet layers have perpendicular magnetic anisotropy. For example, the perpendicular magnetic anisotropy is substantially perpendicular to planes of the fixed and free magnet layers (and in-line with their thicknesses). Such perpendicular magnetic anisotropy may be contrasted with in-plane magnetic anisotropy, which is parallel or in-plane with respect to the plane of the layer. The perpendicular magnetic anisotropy of the fixed and free magnet layers may be provided or established based on the thickness of the layers and/or the interfaces of the layers with their respective adjoining materials. Furthermore, the magnetic tunnel junction apparatus includes an in-plane magnet layer adjacent to the free magnet layer and opposite the fixed magnet layer (e.g., opposite the fixed magnet layer with respect to the barrier layer and the free magnet layer) such that the in-plane magnet layer has in-plane magnetic anisotropy. As discussed, the in-plane magnetic anisotropy is substantially parallel to or in-plane with the in-plane magnet layer.

The in-plane magnetic anisotropy of the in-plane magnet layer may be provided or established based on the thickness of the layer. The magnetic field from the in-plane magnet layer may cant or tilt the magnetization direction or magnetic moment of the free layer in the direction of the in-plane magnetic anisotropy. Such a cant or tilt of the magnetization direction or magnetic moment of the free layer may change the starting angle between the magnetization direction of the free magnet layer and the magnetization direction of the fixed magnet layer (e.g., which would otherwise be essentially zero). Thereby, the free layer may more easily switch with the applied drive current, which may provide for reduced incubation time and drive current. In some embodiments, the magnetic tunnel junction devices or apparatuses having a magnetic tunnel junction including a fixed and free magnet layers with perpendicular magnetic anisotropy separated by a barrier layer and an in-plane magnet layer having in-plane magnetic anisotropy adjacent to the free magnet layer and opposite the fixed magnet layer may be integrated into a non-volatile memory device. For example, the non-volatile memory device may include a first terminal electrode coupled to the in-plane magnet layer and a second terminal electrode coupled to the fixed magnet layer. The first and second electrodes may be coupled to memory cell circuitry including, for example, a bit line, a word line, a source line, and select transistor as is discussed further herein. Such non-volatile memory devices or memory cells may be provide within a memory array for example. These and additional embodiments are discussed further herein with respect to the figures. FIG. 1A is an exploded isometric view of an example magnetic tunnel junction device structure 100 and FIG. IB is a collapsed side view of magnetic tunnel junction device structure 100, arranged in accordance with at least some implementations of the present disclosure. As shown, FIG. 1A provides an exploded isometric view in three dimensional space provided by the illustrated x-, y-, and z-axes and FIG. IB provides a side view along the x-z plane or the y-z plane.

As shown, magnetic tunnel junction device structure 100 may include a terminal electrode 102, an in-plane magnet layer 103, a cap layer 105, a free magnet layer 106, a barrier layer 108, a fixed magnet layer 109, and a terminal electrode 111. Furthermore, free magnet layer 106, barrier layer 108, and fixed magnet layer 109 may provide a magnetic tunnel junction 101 of magnetic tunnel junction device structure 100. As shown, magnetic tunnel junction 101 includes fixed magnet layer 109 and free magnet layer 106 separated by barrier layer 108. As is discussed further below, fixed magnet layer 109 and free magnet layer 106 have perpendicular magnetic anisotropy. Magnetic tunnel junction device structure 100 also includes in-plane magnet layer 103 adjacent to free magnet layer 106 and opposite fixed magnet layer 109.

As shown, in-plane magnet layer 103 has an in-plane magnetic anisotropy 104. In-plane magnet layer 103 may be characterized as an in-plane magnet, an in-plane magnetic layer, a follower layer, an in-plane magnet follower layer an in-plane free layer follower, or the like. Furthermore, in-plane magnetic anisotropy 104 may be characterized as a magnetic direction, a magnetic moment, an easy axis, or the like. As shown, in-plane magnetic anisotropy 104 is in- plane such that a direction of in-plane magnetic anisotropy 104 is along a plane of in-plane magnet layer 103 (e.g., in a direction along the x-y plane) orthogonal to a thickness of in-plane magnet layer 103 (which is in a direction along the z-axis). In-plane magnetic anisotropy 104 is also orthogonal to a direction of drive current provided to magnetic tunnel junction device structure 100 and to a direction from fixed magnet layer 109 through barrier layer 108 to free magnet layer 106 (which are also in a direction along the z-axis). For example, terminal electrode 102, in-plane magnet layer 103, cap layer 105, free magnet layer 106, barrier layer 108, fixed magnet layer 109, and terminal electrode 111 each have thicknesses that are "vertically" aligned along the z-axis and each is disposed "horizontally" along the x-y plane such that the length and width of each is "in-plane" and the thickness is perpendicular thereto.

Furthermore, free magnet layer 106 and fixed magnet layer 109 have perpendicular magnetic isotropies. For example, fixed magnet layer 109 has a perpendicular magnetic anisotropy 110 and free magnet layer 106 has a perpendicular magnetic anisotropy (not shown), such perpendicular magnetic anisotropies may be characterized as magnetic directions, magnetic moments, easy axes, or the like. As shown with respect to perpendicular magnetic anisotropy 110, the perpendicular magnetic anisotropies of free magnet layer 106 and fixed magnet layer 109 have a direction (e.g. , along the z-axis) perpendicular to the planes of free magnet layer 106 and fixed magnet layer 109 (which are a direction along the x-y plane). The perpendicular magnetic anisotropies are parallel to or in line with a direction of drive current provided to magnetic tunnel junction device structure 100 and with a direction from fixed magnet layer 109 through barrier layer 108 to free magnet layer 106 (which are in a direction along the z-axis).

As shown, in-plane magnetic anisotropy 104 may cant or tilt the perpendicular magnetic anisotropy of free magnet layer 106 to provide a canted or tilted magnetic moment 107 in a parallel state 120 of magnetic tunnel junction device structure 100 and a canted or tilted magnetic moment 117 in an anti-parallel state 130 of magnetic tunnel junction device structure 100. For example, magnetic tunnel junction device structure 100 may be characterized as having an in- plane tilt such that in-plane magnetic anisotropy 104 of in-plane magnet layer 103 provides an in- plane tilt to the magnetic moment of free magnet layer 106.

For example, in operation as part of a memory device, a tunnel magnetoresistance (TMR) of magnetic tunnel junction device structure 100 may be sensed (e.g., via terminal electrodes 102, 1 11). In parallel state 120 (e.g., with perpendicular magnetic anisotropy 1 10 and magnetic moment 107 substantially aligned), the TMR may be relatively low while in anti-parallel state 130 (i.e., with magnetic moment 107 substantially misaligned or opposing perpendicular magnetic anisotropy 1 10) the TMR may be relatively high. Furthermore, to change the state of the memory device, a polarized drive current may be provided (e.g., via terminal electrodes 102, 1 11) to switch from magnetic moment 107 of parallel state 120 to magnetic moment 1 17 of anti- parallel state 130 or vice versa. For example, switching between magnetic moment 107 of parallel state 120 to magnetic moment 1 17 of anti-parallel state 130 or vice versa may be provided by a drive current polarized by perpendicular magnetic anisotropy 110 of fixed magnet layer 1 11 such that providing a positive or negative voltage across terminal electrodes 102, 11 1 provides the switching of free magnet layer 106.

FIG. 2 illustrates an example state switching context 200 for magnetic tunnel junction device structure 100, arranged in accordance with at least some implementations of the present disclosure. State switching context 200 may also apply to magnetic tunnel junction device structure 400, which is discussed herein below. FIG. 2 illustrates state switching context 200 for free magnet layer 106 for example. As shown, free magnet layer 106 has a perpendicular magnetic anisotropy as illustrated by easy axis 201. For example, in the absence of in-plane magnetic anisotropy 104 as provided by in-plane magnet layer 103, the magnetic moment of free magnet layer 106 would align with easy axis 201.

Also as shown in FIG. 2, a magnetic moment 202 of free magnet layer 106 (in the illustrated parallel state, please refer to FIG. 1) may be canted or tilted by an angle, Θ, with respect to easy axis 201 based on the influence of magnetic field 204 as provided by in-plane magnetic anisotropy 104 of in-plane magnet layer 103. For example, magnetic field 204 may be from in-plane magnetic anisotropy 104 of in-plane magnet layer 103. Magnetic field 204 may be characterized as a stray field of in-plane magnet layer 103, a stray magnetic field of in-plane magnet layer 103, or the like. Magnetic field 204 may have any suitable magnetic field strength. In an embodiment, in-plane magnet layer 103 has a weaker magnetism than free magnet layer 106. In an embodiment, magnetic field 204 has a field strength of not more than 100 Oersteds. In an embodiment, magnetic field 204 has a field strength in the range of 10 to 50 Oersteds. In an embodiment, magnetic field 204 has a field strength in the range of 50 to 80 Oersteds. In an embodiment, magnetic field 204 has a field strength in the range of 80 to 100 Oersteds. By providing a relatively weak or small magnetic field 204, the stability of free magnet layer 106 may be maintained while advantageous canting or tilting of magnetic moment 202 is provided. Furthermore, such a relatively weak or small magnetic field 204 may not degrade the TMR of magnetic tunnel junction device structure 100. The canting or tilting of magnetic moment 202 may be any suitable angle with respect to easy axis 201. In an embodiment, the angle, Θ, between magnetic moment 202 and easy axis 201 is in the range of 5 to 10 degrees In an embodiment, the angle between magnetic moment 202 and easy axis 201 is in the range of 10 to 20 degrees. In an embodiment, the angle between magnetic moment 202 and easy axis 201 is in the range of 20 to 30 degrees. Although discussed with respect to particular field strengths and canting angles, any suitable field strengths and angles may be used.

In operation, switching from magnetic moment 202 to magnetic moment 205 under the control of spin polarized current 203 may be made easier by canting or tilting magnetic moment 202 with respect to easy axis 201. For example, in the absence of magnetic field 204 as provided by in-plane magnet layer 103, such switching from in-plane with easy axis in the +z-direction to in-plane with easy axis in the -z-direction may be more difficult. By easing the switching from magnetic moment 202 to magnetic moment 205 (or vice versa), lower spin polarized current 203 may be used (reducing power consumption) and/or reduced incubation (e.g., delay) times may be achieved (increasing operation frequency). For example, the spin transfer torque (STT) required to switch from magnetic moment 202 to magnetic moment 205 (or vice versa) may be proportional to cos(6) such that an increase in canting or tilting may provide easier switching. It is also noted that the spin transfer torque (STT) required to switch from magnetic moment 202 to magnetic moment 205 (or vice versa) may not be linearly proportional to sin(6). For example, even a small angle may provide significant improvements. Furthermore, larger angles may provide for instability in the magnetic tunnel junction device structure 100 such that free magnet layer 106 is less stable in maintaining the pertinent magnetic moment of the memory state being held.

Returning now to FIGS. 1A and IB, in-plane magnet layer 103 may include any suitable material or material stack, thickness, or other characteristics that provides in-plane magnetic anisotropy 104. In an embodiment, in-plane magnet layer 103 includes a ferromagnetic material. For example, the thickness of the ferromagnetic material of in-plane magnet layer 103 may establish or provide for in-plane magnetic anisotropy 104. For example, a relatively thick ferromagnetic material may provide for in-plane magnetic anisotropy 104 while providing too thin of a material would provide undesired perpendicular magnetic anisotropy. In an

embodiment, in-plane magnet layer 103 may include a ferromagnetic material having a thickness (i.e., in the z-direction) of not less than 2 nm. In an embodiment, in-plane magnet layer 103 has a thickness in the range of not less than 2 nm to not more than 3 nm. In an embodiment, in-plane magnet layer 103 includes a ferromagnetic material that has a thickness in the range of not less than 2 nm to not more than 3 nm. In an embodiment, in-plane magnet layer 103 has a thickness in the range of not less than 2 nm to not more than 4 nm. In an embodiment, in-plane magnet layer 103 includes one or more of cobalt, iron, boron, and/or nickel. In an embodiment, in-plane magnet layer 103 includes cobalt iron boron (CoFeB). In an embodiment, in-plane magnet layer 103 is a single material while, in other embodiments, in-plane magnet layer 103 includes a stack or layers of differing materials. As shown, in-plane magnet layer 103 may be adjacent to and coupled to terminal electrode 102. In-plane magnet layer 103 may be in contact with terminal electrode 102 or intervening layer(s) may be provided therebetween. Furthermore, in the illustrated embodiment, in-plane magnet layer 103 is adjacent to cap layer 105 (e.g., typically an oxide such as magnesium oxide). In-plane magnet layer 103 may be in contact with cap layer 105 or intervening layer(s) may be provided therebetween. In some embodiments, the thickness of in- plane magnet layer 103 may be increased to compensate for the surface anisotropy caused by the in-plane magnet layer 103 / cap layer 105 boundary.

At the other end of magnetic tunnel junction device structure 100, fixed magnet layer 109 may include any suitable material or material stack, thickness, or other characteristics that provides perpendicular magnetic anisotropy 1 10. Fixed magnet layer 109 may be characterized as a fixed magnet, a fixed magnetic layer, a reference layer, or the like. In an embodiment, fixed magnet layer 109 includes a ferromagnetic material. As shown, fixed magnet layer 109 may be adjacent to and coupled to terminal electrode 11 1. Fixed magnet layer 109 may be in contact with terminal electrode 11 1 or intervening layer(s) may be provided therebetween. In an embodiment, the thickness of the ferromagnetic material of fixed magnet layer 109 and/or the interaction of fixed magnet layer 109 with barrier layer 108 may provide for perpendicular magnetic anisotropy 1 10.

For example, the thickness of a ferromagnetic layer (i.e., fixed or free magnetic layer) may determine its equilibrium magnetization direction. When the thickness of the ferromagnetic layer is above a certain threshold (depending on the material), the ferromagnetic layer exhibits a magnetization direction which is in-plane. When the thickness of the ferromagnetic layer is below a certain threshold (again depending on the material), the ferromagnetic layer exhibits a magnetization direction that is perpendicular to the plane of the magnetic layer. For example, as discussed, a relatively thin ferromagnetic material may provide for perpendicular magnetic anisotropy 110 while providing too thick of a material for fixed magnet layer 109 (or free magnet layer 106) would provide undesired in-plane magnetic anisotropy. Other factors may also influence or determine the direction of magnetization for a ferromagnetic layer. For example, factors such as surface anisotropy (depending on the adjacent layers or a multi -layer composition of the ferromagnetic layer) and/or crystalline anisotropy (depending on stress and the crystal lattice structure modification) may also determine or contribute to the direction of magnetization.

In some embodiments, fixed magnet layer 109 includes a ferromagnetic material having a thickness (i.e., in the z-direction) of not more than 1.5 nm. In an embodiment, fixed magnet layer 109 has a thickness in the range of not less than 0.7 nm to not more than 2 nm. In an

embodiment, fixed magnet layer 109 has a thickness in the range of not less than 0.7 nm to not more than 1.5 nm. In an embodiment, fixed magnet layer 109 includes one or more of cobalt, iron, boron, and/or nickel. In an embodiment, fixed magnet layer 109 includes cobalt iron boron (CoFeB). In an embodiment, fixed magnet layer 109 is a single material while, in other embodiments, fixed magnet layer 109 includes a stack or layers of differing materials.

Furthermore, the interaction of fixed magnet layer 109 and barrier layer 108 may aid and/or provide perpendicular magnetic anisotropy 1 10 through the surface anisotropy therebetween. For example, although barrier layer 108 may be any suitable material, the selection of a magnesium oxide (MgO) may be advantageous in providing perpendicular magnetic anisotropy 110 of fixed magnet layer 109. For example, across a barrier between fixed magnet layer 109 and barrier layer 108, bonds between iron atoms of fixed magnet layer 109 and oxygen atoms of barrier layer may be formed and such bonds may provide or aid perpendicular magnetic anisotropy 110 of fixed magnet layer 109. As discussed further herein, such bonds as well as the crystal structure of a magnesium oxide barrier layer 108 may be provided via an anneal process.

Barrier layer 108 may include any suitable material or materials at any suitable thickness that provides a magnetic tunnel junction between fixed magnet layer 109 and free magnet layer 106. Barrier layer 108 may be characterized as a tunnel barrier, a tunnel barrier layer, a spin filter, or the like. As discussed, in an embedment, barrier layer 108 includes MgO. Barrier layer 108 may also have any suitable thickness. For example, barrier layer 108 may have a thickness (i.e., in the z-direction) of about 1 nm. In an embodiment, barrier layer 108 is MgO having a thickness in the range of not less than 0.5 nm to not more than 2 nm.

Free magnet layer 106 may include any suitable material or material stack, thickness, or other characteristics that provides perpendicular magnetic anisotropy, which may be canted or tilted to provide magnetic moments 107, 117. Free magnet layer 106 may be characterized as a free magnet, a free magnetic layer, a free layer, or the like. In an embodiment, free magnet layer 106 includes a ferromagnetic material. In an embodiment, the thickness of the ferromagnetic material of free magnet layer 106 and/or the interaction of free magnet layer 106 with barrier layer 108 may provide for the perpendicular magnetic anisotropy of free magnet layer 106. For example, as discussed, a relatively thin ferromagnetic material may provide for perpendicular magnetic anisotropy while providing too thick of a material would provide undesired in-plane magnetic anisotropy. For example, free magnet layer 106 may include a ferromagnetic material having a thickness (i.e., in the z-direction) of not more than 1.5 nm. In an embodiment, free magnet layer 106 has a thickness in the range of not less than 0.7 nm to not more than 2 nm. In an embodiment, free magnet layer 106 has a thickness in the range of not less than 0.7 nm to not more than 1.5 nm. In an embodiment, free magnet layer 106 includes one or more of cobalt, iron, boron, and/or nickel. In an embodiment, free magnet layer 106 includes cobalt iron boron (CoFeB).

As discussed with respect to fixed magnet layer 109, the interactions of free magnet layer 106 with barrier layer 108 and cap layer 105 may aid and/or provide the perpendicular magnetic anisotropy of free magnet layer 106 through surface anisotropy between free magnet layer 106 and barrier layer 108 and cap layer 105. For example, across a barrier between free magnet layer 106 and a MgO barrier layer 108 and an oxide cap layer 105, bonds between iron atoms of free magnet layer 106 and oxygen atoms of barrier layer 108 and oxygen atoms of cap layer 105 may provide or aid the perpendicular magnetic anisotropy of free magnet layer 106. In an embodiment, free magnet layer 106 is a single material while, in other

embodiments, free magnet layer 106 includes a stack or layers of differing materials. In some embodiments, free magnet layer 106 includes a stack of materials such that the materials of the stack include one or more of: Co and Pt; Co and Pd; Co and Ni; MgO, CoFeB, Ta, CoFeB, and MgO; MgO, CoFeB, W, CoFeB, and MgO; MgO, CoFeB, V, CoFeB, and MgO; MgO, CoFeB, Mo, CoFeB, and MgO; Mn_xGa_y, materials with Llo symmetry, and/or materials with tetragonal crystal structure.

FIG. 3 illustrates an example multi-material free magnet layer 300, arranged in accordance with at least some implementations of the present disclosure. For example, free magnet layer 300 may be implemented as free magnet layer 106 herein. As shown, in an embodiment, free magnet layer 300 includes first and second cobalt iron boron (CoFeB) layers 301, 303 separated by an insert layer 302. Insert layer 302 may be any suitable material or materials and insert layer 302 may be characterized as a separation layer, an insert, or the like. In an embodiment, insert layer 302 includes one or more of tungsten, tantalum, or molybdenum.

First CoFeB layer 301, insert layer 302, and second CoFeB layer 303 may have any suitable thicknesses. In an embodiment, CoFeB layer 301 has a thickness (i.e., in the z-direction) in the range of not less than 0.3 nm to not more than 1 nm. In an embodiment, insert layer 302 has a thickness (i.e., in the z-direction) in the range of not less than 0.2 nm to not more than 0.4 nm. In an embodiment, CoFeB layer 303 has a thickness (i.e., in the z-direction) in the range of not less than 0.6 nm to not more than 2 nm. In an embodiment, CoFeB layer 301 has a thickness in the range of not less than 0.5 nm to not more than 0.7 nm, insert layer 302 has a thickness in the range of not less than 0.2 nm to not more than 0.4 nm, and CoFeB layer 303 has a thickness in the range of not less than 1.2 nm to not more than 1.5 nm.

Returning to FIGS. 1A and IB, as discussed, in-plane magnet layer 103 may provide a relatively weak or small magnetic field 204 (please refer to FIG. 2) to cant or tilt the

perpendicular magnetic anisotropy of free magnet layer 106. In some embodiments, the magnetization of in-plane magnet layer 103 may be less than one or both of free magnet layer 106 and fixed magnet layer 109. For example, a magnetic permeability of in-plane magnet layer 103 may be less than a magnetic permeability of free magnet layer 106 and/or a magnetic permeability fixed magnet layer 109. The magnetic permeability of such materials may depend on their thicknesses, their material compositions, or the like. In an embodiment, each of in-plane magnet layer 103, free magnet layer 106, magnetic permeability fixed magnet layer 109 include ferromagnetic materials such as Co_xFeyB_z alloys such that x, y, and z indicate the percentages or fractions of each element in the alloy. In an embodiment, the iron (Fe) concentration of in-plane magnet layer 103 is less than that of one or both of free magnet layer 106 and fixed magnet layer 109. Furthermore, magnetic field 204 may be varied based on the thickness of in-plane magnet layer 103 such that a thicker in-plane magnet layer 103 may provide a stronger magnetic field.

Furthermore, the strength of magnetic field 204 may be controlled by the distance between in-plane magnet layer 103 and free magnet layer 106 such that a greater distance decreases the strength of magnetic field 204. The distance between in-plane magnet layer 103 and free magnet layer 106 may controlled by the thickness of cap layer 105 and/or any other intervening layers between in-plane magnet layer 103 and free magnet layer 106. In an embodiment, as discussed with respect to FIGS. 4A and 4B, a metal spacer may also be provided between in-plane magnet layer 103 and free magnet layer 106. In other embodiments, cap layer 105 may be omitted. In an embodiment, cap layer 105 may be omitted and a magnetic buffer layer comprising any suitable low magnetism material or non-ferromagnetic material may be provided between in-plane magnet layer 103 and free magnet layer 106 such as a nitride layer, a non-ferromagnetic metal layer, or the like.

As discussed, magnetic tunnel junction 101 includes fixed magnet layer 109 and free magnet layer 106 separated by barrier layer 108. Furthermore, in-plane magnet layer 103 is adjacent to free magnet layer 106 (with an optional cap layer 105 and/or other intervening layers therebetween) and opposite fixed magnet layer 109. For example, free magnet layer 106 is opposite fixed magnet layer 109 with respect to barrier layer 108 and magnetic tunnel junction 101. In some embodiments, in-plane magnet layer 103 may be on (e.g., in direct contact with) free magnet layer 106 although, as discussed, cap layer 105 may aid in providing the

perpendicular magnetic anisotropy of free magnet layer 106.

Cap layer 105, when employed, may include any suitable material or materials at any suitable thickness that provides enhanced or improved perpendicular magnetic anisotropy of free magnet layer 106. For example, cap layer 105 may include any suitable oxide material such as magnesium oxide, aluminum oxide (AI2O3), or the like. Cap layer 105 may be characterized as a cap, a cap oxide, a cap material layer, an oxide layer, or the like. Cap layer 105 may also have any suitable thickness. For example, cap layer 105 may have a thickness (i.e., in the z-direction) of about 1 nm. In an embodiment, cap layer 105 is MgO having a thickness in the range of not less than 0.5 nm to not more than 2 nm. In an embodiment, cap layer 105 is on free magnet layer 106. As discussed, barrier layer 108 and cap layer 105 may be any suitable material(s). In some embodiments, one or both of barrier layer 108 and cap layer 105 may include one or more of magnesium oxide, aluminum oxide, tungsten oxide, vanadium oxide, indium oxide, ruthenium oxide, magnesium aluminum oxide, hafnium oxide, or tantalum oxide.

Furthermore, although cap layer 105 may enhance in the generation of the perpendicular magnetic anisotropy of free magnet layer 106, cap layer 105 may otherwise provide undesirable tunnel magnetoresistance in magnetic tunnel junction device structure 100. To mitigate such undesirable magnetoresistance, a metal spacer may be provided over or on cap layer 105. FIG. 4A is an exploded isometric view of an example magnetic tunnel junction device structure 400 and FIG. 4B is a collapsed side view of magnetic tunnel junction device structure 400, arranged in accordance with at least some implementations of the present disclosure. As shown, FIG. 4A provides an exploded isometric view in three dimensional space provided by the illustrated x-, y-, and z-axes and FIG. IB provides a side view along the x-z plane or the y-z plane.

As shown in FIGS. 4A and 4B, magnetic tunnel junction device structure 400 may include terminal electrode 102, in-plane magnet layer 103, cap layer 105, a metal spacer 401, free magnet layer 106, barrier layer 108, fixed magnet layer 109, and terminal electrode 111.

Magnetic tunnel junction device structure 400 may include any materials, configurations, characteristics, or the like discussed with respect to magnetic tunnel junction device structure 100. For example, elements of magnetic tunnel junction device structure 400 having shared reference numbers with respect to elements of magnetic tunnel junction device structure 100 may have any of the same characteristic to those described with respect to FIGS. 1 A and IB, but are not limited to such.

As shown, magnetic tunnel junction device structure 400 may include metal spacer 401 on and/or within cap layer 105. As discussed, cap layer 105 may provide undesirable

magnetoresistance in magnetic tunnel junction device structure 400. To mitigate or reduce the magnetoresistance caused by cap layer 105, the surface of cap layer 105 adjacent to in-plane magnet layer 103 may be damaged by the formation of metal spacer 401. For example, the surface of cap layer 105 adjacent to in-plane magnet layer 103 may be damaged to an amorphous or non-crystalline or textured state during the deposition of metal spacer 401. In an embodiment, metal spacer 401 is on cap layer 105. In an embodiment, metal spacer 401 is at least partially embedded in cap layer 105. Metal spacer 401 may include any suitable material or materials that may damage the surface of cap layer 105 adjacent to in-plane magnet layer 103 during the formation of metal spacer 401. For example, metal spacer 401 may include one or more of tantalum, tungsten, zirconium, hafnium, or the like. As discussed further herein, during the deposition of metal spacer 401 , the weight of the deposited species may damage the surface of cap layer 105 adjacent to in-plane magnet layer 103 to reduce the magnetoresistance caused by cap layer 105.

Returning to FIGS. lA and IB, terminal electrodes 102, 11 1 may include any suitable material or materials that provide coupling to magnetic tunnel junction device structure 100. In some embodiments, terminal electrodes 102, 11 1 include one or more of tantalum, tungsten, platinum, copper, or the like.

As shown, in an embodiment, the component layers 102, 103, 105, 106, 108, 109, 11 1 of magnetic tunnel junction device structure 100 may have a substantially circular cross section (e.g., cross sections provided in the x-y plane). However, component layers 102, 103, 105, 106,

108, 109, 1 11 of magnetic tunnel junction device structure 100 may have any suitable cross sectional shape such as oval, square, rectangular, or the like. Furthermore, the cross sectional length and width (i.e., in the x- and y-directions) of component layers 102, 103, 105, 106, 108,

109, 1 11 of magnetic tunnel junction device structure 100 may be any suitable dimensions. Component layers 102, 103, 105, 106, 108, 109, 11 1 may include individual layers having a single material, multiple material layer stacks, or a combination thereof. Furthermore, as indicated with respect to the exploded view provided by FIGS. 1 A and 4A, component layers 102, 103, 105, 106, 108, 109, 11 1 of magnetic tunnel junction device structure 100 may include any suitable intervening layers. As shown in the collapsed view provided by FIGS. IB and 4B, in some embodiments, no intervening layers may be provided. For example, one or more of component layers 102, 103, 105, 106, 108, 109, 1 11 of magnetic tunnel junction device structure 100 may be on one another.

FIG. 5 is a flow diagram illustrating an example process 500 for fabricating magnetic tunnel junction device structures, arranged in accordance with at least some implementations of the present disclosure. For example, process 500 may be implemented to fabricate magnetic tunnel junction device structure 100 and/or magnetic tunnel junction device structure 400 as discussed herein. In the illustrated implementation, process 500 may include one or more operations as illustrated by operations 501-511. However, embodiments herein may include additional operations, certain operations being omitted, or operations being performed out of the order provided. In an embodiment, process 500 may fabricate magnetic tunnel junction device structure 631 over a substrate 601 as discussed further herein with respect to FIGS. 6A-6D.

Process 500 may begin at operation 501 , where a substrate may be received for processing. The substrate may include any suitable substrate such as a silicon wafer or the like. In some embodiments, the substrate includes underlying devices or electrical interconnects or the like. In an embodiment, substrate 601 may be received and processed as discussed with respect to FIGS. 6A-6D.

Processing may continue at operations 502-509, which may be characterized collectively as disposition or deposition operations 512. At each of operations 502-509, the indicated layer (a terminal electrode layer at operation 502, a fixed magnet layer at operation 503, a barrier layer at operation 504, a free magnet layer at operation 505, a cap layer at operation 506, a metal spacer layer at operation 507, an in-plane magnet layer at operation 508, and a terminal electrode layer at operation 509) may be disposed over the layer disposed at the previous operation (or over the received substrate for the terminal electrode layer disposed at operation 502).

Each of the indicated layers may be disposed using any suitable technique or techniques such as deposition techniques. In an embodiment, one, some or all of the layers are deposited using physical vapor deposition techniques. As will be appreciated, such layers may be deposited on the layer disposed at the previous operation (or on the received substrate for the terminal electrode layer disposed at operation 502) or an intervening layer or layers may be between the layer being disposed at the current operation and the layer disposed at the previous operation. Furthermore, some of the layers may be optional. In some embodiments, no metal spacer may be disposed and the in-plane magnet layer may be disposed over or on the cap layer. In some embodiments, no cap layer and no metal spacer may be disposed and the in-plane magnet layer may be disposed over or on the free magnet layer. In an embodiment, the layers disposed at operations 512 are deposited in situ (e.g., in place without being moved or altered between operations) without exposing the layers to an atmospheric environment between such depositions. For example, the layers disposed at operations 512 may be deposited using sequential in situ physical vapor depositions.

For example, at operation 502, a terminal electrode layer may be disposed on or over the substrate received at operation 501 using any suitable technique or techniques such as deposition techniques (e.g., physical vapor deposition). The terminal electrode layer may have any characteristics discussed herein with respect to terminal electrodes 102, 111. At operation 503, a fixed magnet layer may be disposed on or over the terminal electrode layer using any suitable technique or techniques such as deposition techniques (e.g., physical vapor deposition). The fixed magnet layer may have any characteristics discussed herein with respect to fixed magnet layer 109. At operation 504, a barrier layer may be disposed on or over the fixed magnet layer using any suitable technique or techniques such as deposition techniques (e.g., physical vapor deposition). The barrier layer may have any characteristics discussed herein with respect to barrier layer 108. At operation 505, a free magnet layer may be disposed on or over the barrier layer using any suitable technique or techniques such as deposition techniques (e.g., physical vapor deposition). The free magnet layer may have any characteristics discussed herein with respect to free magnet layer 106. At operation 506, a cap layer may be disposed on or over the free magnet layer using any suitable technique or techniques such as deposition techniques (e.g., physical vapor deposition). The cap layer may have any characteristics discussed herein with respect to cap layer 105. At operation 507, a metal spacer layer may be disposed on the cap layer using any suitable technique or techniques such as deposition techniques (e.g., physical vapor deposition). The metal spacer layer may have any characteristics discussed herein with respect to metal spacer 401. At operation 508, an in-plane magnet layer may be disposed on or over the metal spacer layer using any suitable technique or techniques such as deposition techniques (e.g., physical vapor deposition). The in-plane magnet layer may have any characteristics discussed herein with respect to in-plane magnet layer 103. At operation 509, an terminal electrode layer may be disposed on or over the in-plane magnet layer using any suitable technique or techniques such as deposition techniques (e.g., physical vapor deposition). The terminal electrode layer may have any characteristics discussed herein with respect to terminal electrodes 102, 1 11.

Although discussed with respect to depositions in the order of: terminal electrode layer, fixed magnet layer, barrier layer, free magnet layer, cap layer, metal spacer layer, in-plane magnet layer, and terminal electrode layer, in some embodiments, the order may be reversed and the metal spacer layer may be omitted. In such embodiments, the depositions are in the order of: terminal electrode layer, in-plane magnet layer, cap layer, free magnet layer, barrier layer, fixed magnet layer, and terminal electrode layer. Processing may continue from operations 512 at operation 510 where the layers deposited at operations 512 may be patterned. As discussed, in some embodiments, one or more of the layers illustrated in operations 512 may be skipped. The layers received at operation 510 may be patterned using any suitable technique or techniques such as photolithography operations or the like. In an embodiment, a photoresist partem is provided, the terminal electrode disposed at operation 509 is patterned and used as a hard mask to partem the underlying layers. As shown, operation 510 may generate patterned layers including a patterned bottom or first terminal electrode layer, a patterned fixed magnet layer, a patterned barrier layer, a patterned free magnet layer, a patterned cap layer (if implemented), a patterned metal spacer layer (if implemented), a patterned in-plane magnet layer, and a patterned top or second terminal electrode. Processing may continue at operation 511 , where the patterned layers may be annealed and a magnetic field may be applied to the patterned layers to generate a magnetic tunnel junction device structure such as magnetic tunnel junction device structure 100 or magnetic tunnel junction device structure 400. The discussed annealing may be performed at any suitable temperature(s) and duration(s) to set the crystalline structure of the barrier layer and/or to drive boron from one or more of the patterned free magnet layer, the patterned fixed magnet layer, or patterned in-line magnet layer, if applicable. In an embodiment, the anneal operation(s) have a maximum temperature in the range of about 350 to 400°C. Furthermore, the applied magnetic field may be at any suitable field strength such as 1 to 5 Teslas for any suitable duration. Such magnetic field application may establish the magnetism of one or more layers of the in-plane magnet layer, the free magnet layer 106, or the fixed magnet layer. The anneal and magnetic field application may be performed separately or at lest partially simultaneously. FIGS. 6A, 6B, 6C, 6D are side views of example magnetic tunnel junction device structures as particular fabrication operations are performed, arranged in accordance with at least some implementations of the present disclosure. FIGS. 6A, 6B, 6C, 6D illustrates side views of magnetic tunnel junction device structures along the x-z plane or y-z plane in FIGS. 1 A and IB and FIGS. 4A and 4B. As shown in FIG. 6A, magnetic tunnel junction device structure 600 includes substrate 601. For example, substrate 601 may be any substrate such as a substrate wafer received at operation 501. In some examples, substrate 601 may include a semiconductor material such as monocrystalline silicon substrate, a silicon on insulator, or the like. In various examples, substrate 601 may include metallization interconnect layers for integrated circuits or electronic devices such as transistors, memories, capacitors, resistors, optoelectronic devices, switches, or any other active or passive electronic devices separated by an electrically insulating layer, for example, an interlay er dielectric, a trench insulation layer, or the like.

FIG. 6B illustrates a magnetic tunnel junction device structure 611 similar to magnetic tunnel junction device structure 600, after the disposition of a terminal electrode layer 610, a fixed magnet layer 609, a barrier layer 608, a free magnet layer 606, a cap layer 605, a metal spacer layer 604, an in-plane magnet layer 603, and a terminal electrode layer 602. The illustrated layers may be formed using any suitable technique or techniques such as deposition techniques including physical vapor deposition or any other operations discussed with respect to operations 512 or elsewhere herein. As shown, the illustrated layers may be formed in a bulk manner over substrate 601 and in a horizontal manner (e.g., along the x-y plane of substrate 601).

FIG. 6C illustrates a magnetic tunnel junction device structure 621 similar to magnetic tunnel junction device structure 611, after the patterning of terminal electrode layer 610, fixed magnet layer 609, barrier layer 608, free magnet layer 606, cap layer 605, metal spacer layer 604, in-plane magnet layer 603, and terminal electrode layer 602 to provide a patterned terminal electrode layer 620, a patterned fixed magnet layer 619, a patterned barrier layer 618, a patterned free magnet layer 616, a patterned cap layer 615, a patterned metal spacer layer 614, a patterned in-plane magnet layer 613, and a patterned terminal electrode layer 612. The illustrated layers may be patterned using any suitable technique or techniques. In an embodiment,

photolithography techniques may be used to provide a patterned resist layer over terminal electrode layer 602 and etch techniques may be used to pattern the illustrated layers. In an embodiment, the partem of the resist layer may be transferred to terminal electrode layer 602, which may be used as a hardmask to pattern the other layers. FIG. 6D illustrates a magnetic tunnel junction device structure 631 similar to magnetic tunnel junction device structure 621, after one or more annealing operations and the application of a magnetic field to and magnetic tunnel junction device structure 621 to provide terminal electrode 102, in-plane magnet layer 103, cap layer 105, metal spacer 401, free magnet layer 106, barrier layer 108, fixed magnet layer 109, and terminal electrode 111 as discussed herein with respect to FIGS. 1 A and IB and FIGS. 4A and 4B. The discussed annealing operation(s) may be at any suitable temperature(s) and duration(s). In an embodiment, the anneal operation(s) have a maximum temperature in the range of about 350 to 400°C. Such annealing operation(s) may crystallize MgO in barrier layer 108 and/or match the crystalline structure of barrier layer 108 to adjoining CoFeB magnet layers and/or drive boron from one or more layers of in-plane magnet layer 103, free magnet layer 106, or fixed magnet layer 109. Furthermore, the applied magnetic field may be at any suitable field strength such as 1 to 5 Teslas for any suitable duration. Such magnetic field application may establish the magnetism of one or more layers of in-plane magnet layer 103, free magnet layer 106, or fixed magnet layer 109. In an embodiment, the annealing and magnetic field application may be performed at least partially simultaneously such that the annealing is performed in the presence of a 1 to 5 Tesla magnetic field. For example, the annealing duration and the magnetic field application durations may at least partially overlap. In other embodiments, the annealing and magnetic field application may be performed separately.

FIGS. 6A, 6B, 6C, 6D illustrate an example process flow for magnetic tunnel junction device structure 100, magnetic tunnel junction device structure 400, or other magnetic tunnel junction device structures as discussed herein. In various examples, additional operations may be included or certain operations may be omitted. In particular, the illustrated process may provide for magnetic tunnel junction device structures having top terminal electrodes, in-plane magnet layers, cap layers, metal spacers, free magnet layers, barrier layers, fixed magnet layers, and bottom terminal electrodes. However, some of such layers may be omitted or additional intervening layers may be provided. For example, magnetic tunnel junction device structures having only top terminal electrodes, in-plane magnet layers, free magnet layers, barrier layers, fixed magnet layers, and bottom terminal electrodes may be fabricated.

In an embodiment, process 500 and the process flow illustrated with respect to FIGS. 6A, 6B, 6C, 6D provides for: depositing a fixed magnet layer over a substrate, a barrier layer over the fixed magnet layer, a free magnet layer over the barrier layer, and an in-plane magnet layer over the free magnet layer; patterning the fixed magnet layer, the barrier layer, the free magnet layer, and the in-plane magnet layer to provide a magnetic tunnel junction device including a patterned fixed magnet layer, a patterned barrier layer, a patterned free magnet layer, and a patterned in- plane magnet layer; annealing the magnetic tunnel junction device; and applying a magnetic field to the magnetic tunnel junction device.

FIG. 7 is a schematic of a non-volatile memory device 701 including a magnetic tunnel junction device structure having an in-plane magnetic layer, arranged in accordance with at least some implementations of the present disclosure. For example, non-volatile memory device 701 may provide a spin transfer torque memory (STTM) bit cell of a spin transfer torque random access memory (STTRAM). Non-volatile memory device 701 may be implemented in any suitable component or device or the like such as any component discussed with respect to FIGS. 9 and 10. In an embodiment, non-volatile memory device 701 is implemented in a non-volatile memory that is coupled to a processor. For example, the non-volatile memory and processor may be implemented by a system having any suitable form factor. In an embodiment, the system further includes an antenna and a battery such that each of the antenna and the battery are coupled to the processor.

As shown, non-volatile memory device 701 includes a magnetic tunnel junction device structure 710. In the illustrated example, magnetic tunnel junction device structure 710 includes terminal electrode 102, in-plane magnet layer 103, free magnet layer 106, barrier layer 108, fixed magnet layer 109, and terminal electrode 1 11 such that free magnet layer 106, barrier layer 108, fixed magnet layer 109 provide a magnetic tunnel junction 101 of magnetic tunnel junction device structure 710. As shown, magnetic tunnel junction 101 includes fixed magnet layer 109 and free magnet layer 106 separated by barrier layer 108. As discussed herein, fixed magnet layer 109 and free magnet layer 106 have perpendicular magnetic anisotropy. Furthermore, magnetic tunnel junction device structure 710 includes in-plane magnet layer 103 adjacent to free magnet layer 106 and opposite fixed magnet layer 109 such that the in-plane magnet layer 103 has in- plane magnetic anisotropy. Also as shown, magnetic tunnel junction 101 is between terminal electrodes 102, 11 1 , which are coupled to circuitry of non-volatile memory device 701 as discussed below, with terminal electrode 103 coupled to in-plane magnet layer 103 and terminal electrode 1 11 coupled to fixed magnet layer 109.

Although illustrated with terminal electrode 102, in-plane magnet layer 103, free magnet layer 106, barrier layer 108, fixed magnet layer 109, and terminal electrode 11 1, magnetic tunnel junction device structure 710 may include any magnetic tunnel junction device structure discussed herein such as magnetic tunnel junction device structure 100 (e.g., including cap layer 105 between in-plane magnet layer 103 and free magnet layer 106) or magnetic tunnel junction device structure 400 (e.g., including cap layer 105 between in-plane magnet layer 103 and free magnet layer 106 and metal spacer 401 on cap layer 105 and between cap layer 105 and in-plane magnet layer 103).

Also as shown, non-volatile memory device 701 includes a first metal interconnect 792 (e.g., a bit line), a second metal interconnect 791 (e.g., source line), a transistor 715 (e.g., a select transistor) having a first terminal 716, a second terminal 717, and a third terminal 718, and a third metal interconnect 793 (e.g., a word line). Terminal electrode 102 of magnetic tunnel junction device structure 710 is coupled to first metal interconnect 792 and terminal electrode 1 11 of magnetic tunnel junction device structure 710 is coupled to second terminal 717 of transistor 715. Furthermore, first terminal 716 (e.g., a gate terminal) of transistor 715 is coupled to third metal interconnect 793 and third terminal 718 of transistor 715 is coupled to second metal interconnect 791. Such connections may be made in any manner conventional in the art. In Spin Hall Effect (SHE) implementations, terminal electrode 102 is further coupled to a fourth metal interconnect 794 (e.g., maintained at a reference potential relative to first metal interconnect 792). Non-volatile memory device 701 may further include additional read and write circuitry (not shown), a sense amplifier (not shown), a bit line reference (not shown), and the like, as understood by those skilled in the art of non-volatile memory devices. A plurality of non-volatile memory devices 701 may be operably connected to one another to form a memory array (not shown) such that the memory array may be incorporated into a non-volatile memory device.

In operation, non-volatile memory device 701 uses magnetic tunnel junction 101 for switching and detection of the memory state of magnetic tunnel junction 101. For example, non- volatile memory device 701 is read by accessing or sensing the memory state as implemented by a parallel or non-parallel magnetic direction of free magnet layer 106 of magnetic tunnel junction 101. More specifically, the magnetoresistance of magnetic tunnel junction 101 is established by the magnetic direction stored by free magnet layer 106. When the magnetic direction of free magnet layer 106 is substantially parallel (e.g., although canted by in-plane magnet layer 103) with respect to the magnetic direction of fixed magnet layer 109, the magnetic tunnel junction 101 has a low resistance state and, when the magnetic direction of free magnet layer 106 is substantially anti-parallel (e.g., although canted by in-plane magnet layer 103) with respect to the magnetic direction of fixed magnet layer 109, the magnetic tunnel junction 101 has a high resistance state. Such a low or high resistance state may be detected via the circuitry of nonvolatile memory device 701. For write operations, the magnetic direction of free magnet layer 106 is optionally switched between parallel and anti-parallel directions by passing, again via the circuitry of non-volatile memory device 701, a driving current polarized by fixed magnet layer 109 through free magnet layer 106 such that, for example, a positive voltage applied to free magnet layer 106 switches the magnetization direction of free magnet layer 106 to anti-parallel and a negative voltage switches the magnetization direction of free magnet layer 106 to parallel.

As discussed herein, in-plane magnet layer 103 may cant or tilt the magnetic direction of free magnet layer 106 (in both the parallel and anti -parallel states) such that the described switching may occur more easily (e.g., faster) and/or with a lesser drive current such that nonvolatile memory device 701 may operate at a higher frequency and/or with lower power requirements. Also as discussed herein, in-plane magnet layer 103 may cant or tilt the magnetic direction of free magnet layer 106 with a relatively weak stray magnetic field such that the stored magnetic direction of free magnet layer 106 is robust (e.g., not susceptible to arbitrary switching).

As shown, non-volatile memory device 701 includes terminal electrodes 102, 111 and magnetic tunnel junction 101 between terminal electrodes 102, 111 such that magnetic tunnel junction 101 includes fixed magnet layer 109 and free magnet layer 106 separated by barrier layer 108. As discussed herein fixed magnet layer 109 and free magnet layer 106 have in-plane magnetic anisotropy. Also as shown, in-plane magnet layer 103 is adjacent to free magnet layer 106, opposite fixed magnet layer 109, and between terminal electrodes 102, 111. Non-volatile memory device 701 also includes transistor 715 such that terminal electrode 102 is coupled to first metal interconnect 792 (e.g., a bit line), terminal electrode 111 is coupled to second terminal 717 of transistor 715, first terminal 716 of transistor 715 is coupled to third metal interconnect 793 (e.g., a word line), and third terminal 718 of transistor 715 is coupled to second metal interconnect 791 (e.g., source line). As shown, in an embodiment, terminal electrode 102 is coupled to in-plane magnet layer 103 and terminal electrode 111 is coupled to fixed magnet layer 109. In another embodiment, the stack of layers 103, 106, 108, 109 are flipped and terminal electrode 102 is coupled to fixed magnet layer 109 and terminal electrode 111 is coupled to in- plane magnet layer 103. The magnetic tunnel junction device structures discussed herein may be provided in any suitable device (e.g., STTM, STTRAM, etc.) or platform (e.g., computing, mobile, automotive, internet of things, etc.) using any suitable die layout, architecture or the like. Furthermore, nonvolatile memory device 701 or any magnetic tunnel junction device structures may be located on a substrate such as a bulk semiconductor material as part of a wafer. In an embodiment, the substrate is a bulk semiconductor material as part of a chip that has been separated from a wafer. One or more layers of interconnects and/or devices may be between the magnetic tunnel junction device structures and the substrate and/or one or more layers of interconnects and/or devices may be between the magnetic tunnel junction device structures and interconnects above the magnetic tunnel junction device structures.

FIG. 8 illustrates an example cross-sectional die layout 800 including example magnetic tunnel junction device structure 710, arranged in accordance with at least some implementations of the present disclosure. For example, cross-sectional die layout 800 illustrates magnetic tunnel junction device structure 710 formed in metal 3 (M3) and metal 2 (M2) layer regions thereof. Although illustrated with respect to magnetic tunnel junction device structure 710, any magnetic tunnel junction device structure discussed herein may be implemented in the die layout of FIG. 8. As shown in FIG. 8, cross-sectional die layout 800 illustrates an active region having a transistor MN including diffusion region 801 , a gate terminal 802, a drain terminal 804, and a source terminal 803. For example, transistor MN may implement transistor 715 (with gate terminal 802 being first terminal 716, drain terminal 804 being second terminal 717, and source terminal 803 being third terminal 718), the source line (SL) may implement second metal interconnect 791, and the bit-line may implement first metal interconnect 792.

As shown, source terminal 803 is coupled to SL (source line) via poly or via, where the SL is formed in metal 0 (M0). In some embodiments, drain terminal 804 is coupled to MOa (also in metal 0) through a via 805. Drain terminal 804 is coupled to magnetic tunnel junction device structure 710 through via 0-1 (e.g., a via layer that connects metal 0 to metal 1 layers), metal 1 (Ml), via 1 -2 (e.g., a via layer that connects metal 1 to metal 2 layers), and metal 2 (M2).

Magnetic tunnel junction device structure 710 is coupled to a bit-line in metal 4 (M4). In some embodiments, magnetic tunnel junction device structure 710 is formed in the metal 3 (M3) region. In some embodiments, transistor MN is formed in or on the front side of a die while magnetic tunnel junction device structure 710 is located in or the back end of the die. In some embodiments, magnetic tunnel junction device structure 710 is located in the back end metal layers or via layers for example in Via 3.

Although illustrated with magnetic tunnel junction device structure 710 formed in metal 3 (M3), magnetic tunnel junction device structure 710 may be formed in any suitable layer of cross-sectional die layout 800. In some embodiments, magnetic tunnel junction device structure 710 is formed in metal 2 and/or metal 1 layer regions. In such embodiments, magnetic tunnel junction device structure 710 may directly connect to MOa and the bit-line may be formed in metal 3 or metal 4.

FIG. 9 illustrates a system 900 in which a mobile computing platform 905 and/or a data server machine 906 employs a magnetic tunnel junction device having an in-plane magnet layer, arranged in accordance with at least some implementations of the present disclosure. Data server machine 906 may be any commercial server, for example, including any number of high- performance computing platforms disposed within a rack and networked together for electronic data processing, which in the exemplary embodiment includes a packaged device 950. For example, device 950 (e.g., a memory or processor) may include a magnetic tunnel junction device having an in-plane magnet layer. In an embodiment, device 950 includes a non-volatile memory including a magnetic tunnel junction device having an in-plane magnet layer such as any magnetic tunnel junction device structure discussed herein. As discussed below, in some examples, device 950 may include a system on a chip (SOC) such as SOC 960, which is illustrated with respect to mobile computing platform 905.

Mobile computing platform 905 may be any portable device configured for each of electronic data display, electronic data processing, wireless electronic data transmission, or the like. For example, mobile computing platform 905 may be any of a tablet, a smart phone, a laptop computer, etc., and may include a display screen (e.g., a capacitive, inductive, resistive, or optical touchscreen), a chip-level or package-level integrated system 910, and a battery 915. Although illustrated with respect to mobile computing platform 905, in other examples, chip- level or package-level integrated system 910 and a battery 915 may be implemented in a desktop computing platform, an automotive computing platform, an internet of things platform, or the like. Whether disposed within integrated system 910 illustrated in expanded view 920 or as a stand-alone packaged device within data server machine 906, SOC 960 may include memory circuitry and/or processor circuitry 940 (e.g., RAM, a microprocessor, a multi-core

microprocessor, graphics processor, etc.), a PMIC 930, a controller 935, and a radio frequency integrated circuit (RFIC) 925 (e.g., including a wideband RF transmitter and/or receiver

(TX/RX)). As shown, one or more magnetic tunnel junction devices having in-plane magnet layers such as any magnetic tunnel junction device structure discussed herein may be employed via memory circuitry and/or processor circuitry 940. In some embodiments, RFIC 925 includes a digital baseband and an analog front end module further comprising a power amplifier on a transmit path and a low noise amplifier on a receive path). Functionally, PMIC 930 may perform battery power regulation, DC-to-DC conversion, etc., and so has an input coupled to battery 915, and an output providing a current supply to other functional modules. As further illustrated in

FIG. 9, in the exemplary embodiment, RFIC 925 has an output coupled to an antenna (not shown) to implement any of a number of wireless standards or protocols, including but not limited to Wi- Fi (IEEE 802.11 family), WiMAX (IEEE 802.16 family), IEEE 802.20, long term evolution (LTE), Ev-DO, HSPA+, HSDPA+, HSUPA+, EDGE, GSM, GPRS, CDMA, TDMA, DECT, Bluetooth, derivatives thereof, as well as any other wireless protocols that are designated as 3G, 4G, 5G, and beyond. Memory circuitry and/or processor circuitry 940 may provide memory functionality for SOC 960, high level control, data processing and the like for SOC 960. In alternative implementations, each of the SOC modules may be integrated onto separate ICs coupled to a package substrate, interposer, or board. FIG. 10 is a functional block diagram of a computing device 1000, arranged in

accordance with at least some implementations of the present disclosure. Computing device 1000 or portions thereof may be implemented via one or both of data server machine 906 or mobile computing platform 905, for example, and further includes a motherboard 1002 hosting a number of components, such as but not limited to a processor 1001 (e.g., an applications processor) and one or more communications chips 1004, 1005. Processor 1001 may be physically and/or electrically coupled to motherboard 1002. In some examples, processor 1001 includes an integrated circuit die packaged within the processor 1001. In general, the term "processor" may refer to any device or portion of a device that processes electronic data from registers and/or memory to transform that electronic data into other electronic data that may be stored in registers and/or memory.

In various examples, one or more communication chips 1004, 1005 may also be physically and/or electrically coupled to the motherboard 1002. In further implementations, communication chips 1004 may be part of processor 1001. Depending on its applications, computing device 1000 may include other components that may or may not be physically and electrically coupled to motherboard 1002. These other components may include, but are not limited to, volatile memory (e.g., DRAM) 1007, 1008, non-volatile memory (e.g., ROM) 1010, a graphics processor 1012, flash memory, global positioning system (GPS) device 1013, compass 1014, a chipset 1006, an antenna 1016, a power amplifier 1009, a touchscreen controller 1011, a touchscreen display 1017, a speaker 1015, a camera 1003, and a battery 1018, as illustrated, and other components such as a digital signal processor, a crypto processor, an audio codec, a video codec, an accelerometer, a gyroscope, and a mass storage device (such as hard disk drive, solid state drive (SSD), compact disk (CD), digital versatile disk (DVD), and so forth), or the like.

Communication chips 1004, 1005 may enable wireless communications for the transfer of data to and from the computing device 1000. The term "wireless" and its derivatives may be used to describe circuits, devices, systems, methods, techniques, communications channels, etc., that may communicate data through the use of modulated electromagnetic radiation through a non- solid medium. The term does not imply that the associated devices do not contain any wires, although in some embodiments they might not. Communication chips 1004, 1005 may implement any of a number of wireless standards or protocols, including but not limited to those described elsewhere herein. As discussed, computing device 1000 may include a plurality of communication chips 1004, 1005. For example, a first communication chip may be dedicated to shorter range wireless communications such as Wi-Fi and Bluetooth and a second

communication chip may be dedicated to longer range wireless communications such as GPS, EDGE, GPRS, CDMA, WiMAX, LTE, Ev-DO, and others. For example, any component of computing device 1000 may include or utilize one or more magnetic tunnel junction devices having an in-plane magnet layer such as any magnetic tunnel junction device structure(s) discussed herein.

As used in any implementation described herein, the term "module" refers to any combination of software, firmware and/or hardware configured to provide the functionality described herein. The software may be embodied as a software package, code and/or instruction set or instructions, and "hardware", as used in any implementation described herein, may include, for example, singly or in any combination, hardwired circuitry, programmable circuitry, state machine circuitry, and/or firmware that stores instructions executed by programmable circuitry. The modules may, collectively or individually, be embodied as circuitry that forms part of a larger system, for example, an integrated circuit (IC), system on-chip (SoC), and so forth.

While certain features set forth herein have been described with reference to various implementations, this description is not intended to be construed in a limiting sense. Hence, various modifications of the implementations described herein, as well as other implementations, which are apparent to persons skilled in the art to which the present disclosure pertains are deemed to lie within the spirit and scope of the present disclosure.

The following examples pertain to further embodiments.

In one or more first embodiments, an apparatus comprises a magnetic tunnel junction including a fixed magnet layer and a free magnet layer separated by a barrier layer, the fixed and free magnet layers having perpendicular magnetic anisotropy and an in-plane magnet layer adjacent to the free magnet layer and opposite the fixed magnet layer, the in-plane magnet layer having in-plane magnetic anisotropy.

In one or more second embodiments, for any of the first embodiments, the in-plane magnet layer comprises cobalt, iron, and boron and has a thickness of not less than 2 nanometers.

In one or more third embodiments, for any of the first or second embodiments, the in- plane magnet layer comprises a ferromagnetic material and has a thickness of not less than 2 nanometers and not more than 3 nanometers.

In one or more fourth embodiments, for any of the first through third embodiments, the in-plane magnet layer applies a magnetic field of not more than 100 Oersteds to the free magnet layer.

In one or more fifth embodiments, for any of the first through fourth embodiments, a magnetic permeability of the in-plane magnet layer is less than a magnetic permeability of the free magnet layer.

In one or more sixth embodiments, for any of the first through fifth embodiments, the apparatus further comprises an oxide layer between the free magnet layer and the in-plane magnet layer. In one or more seventh embodiments, for any of the first through sixth embodiments, the apparatus further comprises an oxide layer between the free magnet layer and the in-plane magnet layer such that the oxide layer is on the free magnet layer and the oxide layer comprises at least one of magnesium oxide or aluminum oxide.

In one or more eighth embodiments, for any of the first through seventh embodiments, the apparatus further comprises an oxide layer between the free magnet layer and the in-plane magnet layer and a metal spacer layer between the oxide layer and the free magnet layer.

In one or more ninth embodiments, for any of the first through eighth embodiments, the apparatus further comprises an oxide layer between the free magnet layer and the in-plane magnet layer and a metal spacer layer between the oxide layer and the free magnet layer such that the metal spacer layer is on the oxide layer.

In one or more tenth embodiments, for any of the first through ninth embodiments, the apparatus further comprises an oxide layer between the free magnet layer and the in-plane magnet layer and a metal spacer layer between the oxide layer and the free magnet layer, such that the metal spacer layer is on the oxide layer and the metal spacer layer comprises at least one of tantalum, tungsten, zirconium, or hafnium.

In one or more eleventh embodiments, for any of the first through tenth embodiments, the fixed magnet layer comprises cobalt, iron, and boron and has a thickness of not more than 1.5 nanometers, the barrier layer comprises magnesium oxide, the free magnet layer comprises cobalt, iron, and boron and has a thickness of not more than 2 nanometers, and the in-plane magnet layer comprises cobalt, iron, and boron and has a thickness of not less than 2 nanometers.

In one or more twelfth embodiments, for any of the first through eleventh embodiments, the fixed magnet layer comprises cobalt, iron, and boron and has a thickness of not more than 1.5 nanometers, the barrier layer comprises magnesium oxide, the free magnet layer comprises cobalt, iron, and boron and has a thickness of not more than 2 nanometers, and the in-plane magnet layer comprises cobalt, iron, and boron and has a thickness of not less than 2 nanometers such that the free magnet layer comprises an insert layer between first and second cobalt iron boron layers, the insert layer comprising at least one of tungsten, tantalum, or molybdenum. In one or more thirteenth embodiments, a system includes a processor and a non-volatile memory coupled to the processor, the non-volatile memory including an apparatus according to any of the first through twelfth embodiments.

In one or more fourteenth embodiments, for any of the thirteenth embodiments, the system further includes an antenna coupled to the processor and a battery coupled to the processor.

In one or more fifteenth embodiments, a system includes a means for storing data including an apparatus according to any of the first through twelfth embodiments and a means for processing the stored data coupled to the means for storing data.

In one or more sixteenth embodiments, for any of the fifteenth embodiments, the system further includes a means for transmitting wireless data coupled to the means for processing the stored data.

In one or more seventeenth embodiments, a non-volatile memory device comprises a first electrode, a second electrode coupled to a bit line of a memory array, a magnetic tunnel junction between the first and second electrodes, the magnetic tunnel junction including a fixed magnet layer and a free magnet layer separated by a barrier layer, the fixed and free magnet layers having perpendicular magnetic anisotropy, an in-plane magnet layer adjacent to the free magnet layer and opposite the fixed magnet layer, the in-plane magnet layer having in-plane magnetic anisotropy, and a transistor with a first terminal coupled to the first electrode, a second terminal coupled to a source line of the memory array, and a third terminal coupled to a word line of the memory array.

In one or more eighteenth embodiments, for any of the seventeenth embodiments, the first electrode is coupled to the in-plane magnet layer and the second electrode is coupled to the fixed magnet layer.

In one or more nineteenth embodiments, for any of the seventeenth or eighteenth embodiments, the in-plane magnet layer comprises cobalt, iron, and boron and has a thickness of not less than 2 nanometers.

In one or more twentieth embodiments, for any of the seventeenth through nineteenth embodiments, a magnetic permeability of the in-plane magnet layer is less than a magnetic permeability of the free magnet layer and the in-plane magnet layer applies a magnetic field of not more than 100 Oersteds to the free magnet layer.

In one or more twenty-first embodiments, for any of the seventeenth through nineteenth embodiments, the non-volatile memory device further comprises an oxide layer between the free magnet layer and the in-plane magnet layer and a metal spacer layer between the oxide layer and the free magnet layer.

In one or more twenty-second embodiments, for any of the seventeenth through twenty- first embodiments, the fixed magnet layer comprises cobalt, iron, and boron and has a thickness of not more than 1.5 nanometers, the barrier layer comprises magnesium oxide, the free magnet layer comprises cobalt, iron, and boron and has a thickness of not more than 2 nanometers, and the in-plane magnet layer comprises cobalt, iron, and boron and has a thickness of not less than 2 nanometers.

In one or more twenty -third embodiments, a system comprises a means for storing data including a magnetic tunnel junction including a fixed magnet layer and a free magnet layer separated by a barrier layer, the fixed and free magnet layers having perpendicular magnetic anisotropy and an in-plane magnet layer adjacent to the free magnet layer and opposite the fixed magnet layer, the in-plane magnet layer having in-plane magnetic anisotropy, and a means for processing the stored data coupled to the means for storing data.

In one or more twenty -fourth embodiments, for any of the twent -third embodiments, the first electrode is coupled to the in-plane magnet layer and the second electrode is coupled to the fixed magnet layer.

In one or more twenty-fifth embodiments, for any of the twenty -third or twenty-fourth embodiments, the in-plane magnet layer comprises cobalt, iron, and boron and has a thickness of not less than 2 nanometers.

In one or more twenty-sixth embodiments, for any of the twenty -third through twenty- fifth embodiments, a magnetic permeability of the in-plane magnet layer is less than a magnetic permeability of the free magnet layer and the in-plane magnet layer applies a magnetic field of not more than 100 Oersteds to the free magnet layer. In one or more twenty-seventh embodiments, for any of the twenty -third through twenty- sixth embodiments, the system further comprises an oxide layer between the free magnet layer and the in-plane magnet layer and a metal spacer layer between the oxide layer and the free magnet layer.

In one or more twenty-eighth embodiments, for any of the twenty -third through twenty- seventh embodiments, the fixed magnet layer comprises cobalt, iron, and boron and has a thickness of not more than 1.5 nanometers, the barrier layer comprises magnesium oxide, the free magnet layer comprises cobalt, iron, and boron and has a thickness of not more than 2 nanometers, and the in-plane magnet layer comprises cobalt, iron, and boron and has a thickness of not less than 2 nanometers.

In one or more twenty -ninth embodiments, a method comprises depositing a fixed magnet layer over a substrate, a barrier layer over the fixed magnet layer, a free magnet layer over the barrier layer, and an in-plane magnet layer over the free magnet layer, patterning the fixed magnet layer, the barrier layer, the free magnet layer, and the in-plane magnet layer to provide a magnetic tunnel junction device including a patterned fixed magnet layer, a patterned barrier layer, a patterned free magnet layer, and a patterned in-plane magnet layer, annealing the magnetic tunnel junction device, and applying a magnetic field to the magnetic tunnel junction device.

In one or more thirtieth embodiments, for any of the twenty -ninth embodiments, said depositing comprises in situ sequential physical vapor deposition of the fixed magnet layer, the barrier layer, the free magnet layer, and the in-plane magnet layer.

In one or more thirty-first embodiments, for any of the twenty-ninth or thirtieth embodiments, said annealing and said applying the magnetic field are performed simultaneously and the magnetic field has a peak magnetic field of not less than 1 Tesla.

In one or more thirty-second embodiments, for any of the twenty -ninth through thirty -first embodiments, said depositing comprises in situ sequential physical vapor deposition of the fixed magnet layer, the barrier layer, the free magnet layer, and the in-plane magnet layer and/or said annealing and said applying the magnetic field are performed simultaneously with the magnetic field having a peak magnetic field of not less than 1 Tesla. In one or more thirty -third embodiments, for any of the twenty-ninth through thirty- second embodiments, said depositing further comprises depositing an oxide cap layer on the free magnet layer and a metal spacer layer on the oxide cap layer.

In one or more thirty-fourth embodiments, for any of the twenty -ninth through thirty -third embodiments, the in-plane magnet layer comprises a ferromagnetic material and has a thickness of not less than 2 nanometers and not more than 3 nanometers.

In one or more thirty -fifth embodiments, for any of the twenty -ninth through thirty- fourth embodiments, the fixed magnet layer comprises cobalt, iron, and boron and has a thickness of not more than 1.5 nanometers, the barrier layer comprises magnesium oxide, the free magnet layer comprises cobalt, iron, and boron and has a thickness of not more than 2 nanometers, and the in-plane magnet layer comprises cobalt, iron, and boron and has a thickness of not less than 2 nanometers.

In one or more thirty-sixth embodiments, for any of the twenty -ninth through thirty- fifth embodiments, the in-plane magnet layer comprises a ferromagnetic material and has a thickness of not less than 2 nanometers and not more than 3 nanometers and/or the fixed magnet layer comprises cobalt, iron, and boron and has a thickness of not more than 1.5 nanometers.

It will be recognized that the invention is not limited to the embodiments so described, but can be practiced with modification and alteration without departing from the scope of the appended claims. For example, the above embodiments may include specific combination of features. However, the above embodiments are not limited in this regard and, in various implementations, the above embodiments may include the undertaking only a subset of such features, undertaking a different order of such features, undertaking a different combination of such features, and/or undertaking additional features than those features explicitly listed. The scope of the invention should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.

Claims

What is claimed is: 1. An apparatus comprising:

a magnetic tunnel junction including a fixed magnet layer and a free magnet layer separated by a barrier layer, the fixed and free magnet layers having perpendicular magnetic anisotropy; and

an in-plane magnet layer adjacent to the free magnet layer and opposite the fixed magnet layer, the in-plane magnet layer having in-plane magnetic anisotropy.

2. The apparatus of claim 1, wherein the in-plane magnet layer comprises cobalt, iron, and boron and has a thickness of not less than 2 nanometers.

3. The apparatus of claim 1, wherein the in-plane magnet layer comprises a ferromagnetic material and has a thickness of not less than 2 nanometers and not more than 3 nanometers.

4. The apparatus of claim 1, wherein the in-plane magnet layer applies a magnetic field of not more than 100 Oersteds to the free magnet layer.

5. The apparatus of claim 1 , wherein a magnetic permeability of the in-plane magnet layer is less than a magnetic permeability of the free magnet layer.

6. The apparatus of claim 1, further comprising:

an oxide layer between the free magnet layer and the in-plane magnet layer.

7. The apparatus of claim 6, wherein the oxide layer is on the free magnet layer and wherein the oxide layer comprises at least one of magnesium oxide or aluminum oxide.

8. The apparatus of claim 6, further comprising:

a metal spacer layer between the oxide layer and the free magnet layer, wherein the metal spacer layer is on the oxide layer and the metal spacer layer comprises at least one of tantalum, tungsten, zirconium, or hafnium.

9. The apparatus of claim 1 , wherein the fixed magnet layer comprises cobalt, iron, and boron and has a thickness of not more than 1.5 nanometers, the barrier layer comprises magnesium oxide, the free magnet layer comprises cobalt, iron, and boron and has a thickness of not more than 2 nanometers, and the in-plane magnet layer comprises cobalt, iron, and boron and has a thickness of not less than 2 nanometers.

10. A system comprising:

a processor; and

a non-volatile memory coupled to the processor, the non-volatile memory including an apparatus according to any of claims 1 to 9.

1 1. The system of claim 10, further comprising:

an antenna coupled to the processor; and

a battery coupled to the processor.

12. A system comprising:

a means for storing data including an apparatus according to any of claims 1 to 9; and a means for processing the stored data coupled to the means for storing data.

13. The system of claim 16, further comprising:

a means for transmitting wireless data coupled to the means for processing the stored data.

14. A non-volatile memory device comprising:

a first electrode;

a second electrode coupled to a bit line of a memory array;

a magnetic tunnel junction between the first and second electrodes, the magnetic tunnel junction including a fixed magnet layer and a free magnet layer separated by a barrier layer, the fixed and free magnet layers having perpendicular magnetic anisotropy;

an in-plane magnet layer adjacent to the free magnet layer and opposite the fixed magnet layer, the in-plane magnet layer having in-plane magnetic anisotropy; and

a transistor with a first terminal coupled to the first electrode, a second terminal coupled to a source line of the memory array, and a third terminal coupled to a word line of the memory array.

15. The non-volatile memory device of claim 14, wherein the first electrode is coupled to the in-plane magnet layer and the second electrode is coupled to the fixed magnet layer.

16. The non-volatile memory device of claim 14, wherein the in-plane magnet layer comprises cobalt, iron, and boron and has a thickness of not less than 2 nanometers.

17. The non-volatile memory device of claim 14, wherein a magnetic permeability of the in- plane magnet layer is less than a magnetic permeability of the free magnet layer and wherein the in-plane magnet layer applies a magnetic field of not more than 100 Oersteds to the free magnet layer.

18. The non-volatile memory device of claim 14, further comprising:

an oxide layer between the free magnet layer and the in-plane magnet layer; and a metal spacer layer between the oxide layer and the free magnet layer.

19. The non-volatile memory device of claim 14, wherein the fixed magnet layer comprises cobalt, iron, and boron and has a thickness of not more than 1.5 nanometers, the barrier layer comprises magnesium oxide, the free magnet layer comprises cobalt, iron, and boron and has a thickness of not more than 2 nanometers, and the in-plane magnet layer comprises cobalt, iron, and boron and has a thickness of not less than 2 nanometers.

20. A method comprising:

depositing a fixed magnet layer over a substrate, a barrier layer over the fixed magnet layer, a free magnet layer over the barrier layer, and an in-plane magnet layer over the free magnet layer;

patterning the fixed magnet layer, the barrier layer, the free magnet layer, and the in-plane magnet layer to provide a magnetic tunnel junction device including a patterned fixed magnet layer, a patterned barrier layer, a patterned free magnet layer, and a patterned in-plane magnet layer;

annealing the magnetic tunnel junction device; and

applying a magnetic field to the magnetic tunnel junction device.

21. The method of claim 20, wherein said depositing comprises in situ sequential physical vapor deposition of the fixed magnet layer, the barrier layer, the free magnet layer, and the in- plane magnet layer.

22. The method of claim 20, wherein said annealing and said applying the magnetic field are performed simultaneously and wherein the magnetic field has a peak magnetic field of not less than 1 Tesla.

23. The method of claim 20, wherein said depositing further comprises depositing an oxide cap layer on the free magnet layer and a metal spacer layer on the oxide cap layer.

24. The method of claim 20, wherein the in-plane magnet layer comprises a ferromagnetic material and has a thickness of not less than 2 nanometers and not more than 3 nanometers.

25. The method of claim 20, wherein the fixed magnet layer comprises cobalt, iron, and boron and has a thickness of not more than 1.5 nanometers, the barrier layer comprises magnesium oxide, the free magnet layer comprises cobalt, iron, and boron and has a thickness of not more than 2 nanometers, and the in-plane magnet layer comprises cobalt, iron, and boron and has a thickness of not less than 2 nanometers.