Yptbi 1:1:1 composition design using krypton sputtering in a deposition system

Abstract

The present disclosure relates generally to topological semimetal (TSM)-based spin-orbit torque (SOT) devices and methods of forming TSM layers. The TSM layer of the SOT device includes YPtBi having a 1:1:1 stoichiometric ratio. The YPtBi has a density between about 9.7 g / cc to about 11.2 g / cc. Kr, Ar, or Xe gas is used to sputter the YPtBi to form the YPtBi layer or film. Trace amounts of Kr, Ar, or Xe are detectable in the YPtBi layer, where the YPtBi layer includes about 1% Kr, Ar, or Xe. In forming the YPtBi layer, one or more targets including: YPtBi; YPt and Bi; PtBi and Y; Y, Pt, and Bi; or YBi and Pt can be used. In embodiments where two targets are used to form the YPtBi layer, different amounts of power can be applied to each target.

Description

Cross-references to related applications

[0001] This application claims the benefit of U.S. Patent Application Serial No. 19 / 011,206, filed January 6, 2025, and U.S. Provisional Patent Application Serial No. 63 / 554,533, filed February 16, 2024, which is incorporated herein by reference. Background Technology

[0002] Invention Field

[0003] The embodiments disclosed herein generally relate to spin-orbit torque (SOT) devices comprising a topological half-metal (TSM) layer.

[0004] Related technical descriptions

[0005] YPtBi layers are narrow-bandgap topological half-metals exhibiting a giant spin Hall effect and high electrical conductivity. YPtBi is a material proposed for various spin-orbit torque (SOT) device applications, such as spin Hall layers for magnetoresistive random access memory (MRAM) devices, magnetic recording read heads, sensors, and energy-assisted magnetic recording (EAMR) magnetic recording heads. However, several obstacles may exist in utilizing YPtBi materials in commercial SOT applications. For example, YPtBi materials require specific buffer layers and / or sandwiches, as well as optimal processing conditions to achieve the desired orientation.

[0006] Therefore, there is a need for an improved SOT device that utilizes a TSM layer with a desired crystal orientation. Summary of the Invention

[0007] This disclosure generally relates to a spin-orbit torque (SOT) device based on topological half-metals (TSMs) and a method for forming a TSM layer. The TSM layer of the SOT device comprises YPtBi with a stoichiometric ratio of 1:1:1. The YPtBi has a density between about 9.7 g / cc and about 11.2 g / cc. Kr, Ar, or Xe gases are used to sputter the YPtBi to form a YPtBi layer or film. Trace amounts of Kr, Ar, or Xe are detectable in the YPtBi layer, wherein the YPtBi layer contains about 1% or less of Kr, Ar, or Xe. When forming the YPtBi layer, one or more targets comprising YPtBi, YPt and Bi, PtBi and Y, or YBi and Pt can be used. In embodiments where two targets are used to form the YPtBi layer, different amounts of power can be applied to each target. The 1:1:1 stoichiometric ratio of YPtBi results in a high spin Hall angle during operation.

[0008] In one embodiment, the spin orbital torque (SOT) device includes a YPtBi layer having a stoichiometric ratio of 1:1:1 and a density between about 9.7 g / cc and about 11.2 g / cc.

[0009] In another embodiment, a method for forming a YPtBi film having a 1:1:1 stoichiometric ratio includes: loading a substrate onto a chuck heated to about 300°C to about 600°C in a deposition chamber; loading a YPt target and a Bi target in the deposition chamber; adjusting the flow rate, pressure, and substrate bias of a Kr, Ar, or Xe gas in the deposition chamber; and applying power and the Kr, Ar, or Xe gas to sputter the YPt target and the Bi target to form a film comprising a YPtBi film having a 1:1:1 stoichiometric ratio and a density between about 9.7 g / cc and about 11.2 g / cc.

[0010] In another embodiment, a method for forming a YPtBi film having a stoichiometric ratio of 1:1:1 includes: loading a substrate onto a chuck heated to about 300°C to about 600°C in a deposition chamber; placing one of the following target combinations in the deposition chamber: 1) a YBi target and a Pt target; 2) a PtBi target and a Bi target; or 3) a Y target, a Pt target, and a Bi target; adjusting the Kr, Ar, or Xe gas flow rate, pressure, and substrate bias of the deposition chamber; and applying power and Kr, Ar, or Xe gas to sputter the YBi target and the Pt target to form a YPtBi film having a stoichiometric ratio of 1:1:1 and a density between about 9.7 g / cc and about 11.2 g / cc. Attached Figure Description

[0011] Therefore, a detailed understanding of the foregoing features of this disclosure, a more specific description of this disclosure, and the foregoing brief overview can be obtained by referring to the embodiments, some of which are illustrated in the accompanying drawings. However, it should be noted that the drawings only exemplify typical embodiments of this disclosure and should therefore not be construed as limiting its scope, as this disclosure allows for other equally effective embodiments.

[0012] Figure 1 This is a schematic diagram of some embodiments of a magnetic media driver that includes a magnetic recording head with an SOT MTJ device.

[0013] Figure 2 This is a partial cross-sectional view of some implementations of a read / write head with an SOT MTJ device.

[0014] Figures 3A and 3B illustrate spin-orbit torque (SOT) devices according to various embodiments.

[0015] Figures 4A to 4C A method for forming YPtBi with a 1:1:1 composition according to various embodiments is shown.

[0016] Figure 5A A graph according to one embodiment is shown, which illustrates the relationship between the power (W) applied to a Bi target and the power (W) applied to a YPt target.

[0017] Figure 5B A graph according to one embodiment is shown, which illustrates the relationship between the stoichiometry of YPt and the Kr gas flow rate (sccm).

[0018] Figure 6A In MAMR magnetic recording heads such as Figure 1 A schematic cross-sectional view of the SOT device used in the MAMR magnetic recording head of a driver or other suitable magnetic media driver.

[0019] Figures 6B to 6C It has Figure 6A A schematic MFS view of a portion of the MAMR magnetic recording head of an SOT device.

[0020] Figure 7 This is a schematic cross-sectional view of the SOT MTJ used as an MRAM device.

[0021] For ease of understanding, the same reference numerals are used where possible to denote the same elements common in the figures. It is conceivable that elements disclosed in one embodiment may be advantageously used in other embodiments without specific description. Detailed Implementation

[0022] In the following text, reference is made to embodiments of this disclosure. However, it should be understood that this disclosure is not limited to the specifically described embodiments. Rather, any combination of the following features and elements (whether or not related to different embodiments) is contemplated to implement and practice this disclosure. Furthermore, while embodiments of this disclosure may achieve advantages over other possible solutions and / or the prior art, whether a given embodiment achieves a particular advantage is not a limitation of this disclosure. Therefore, the following aspects, features, embodiments, and benefits are merely illustrative and should not be considered elements or limitations of the appended claims unless expressly stated in the claims. Similarly, reference to “this disclosure” should not be construed as a generalization of any inventive subject matter disclosed herein and should not be considered an element or limitation of the appended claims unless expressly stated in the claims.

[0023] This disclosure generally relates to a spin-orbit torque (SOT) device based on topological half-metals (TSMs) and a method for forming a TSM layer. The TSM layer of the SOT device comprises YPtBi with a stoichiometric ratio of 1:1:1. The YPtBi has a density between about 9.7 g / cc and about 11.2 g / cc. Kr, Ar, or Xe gases are used to sputter the YPtBi to form a YPtBi layer or film. Trace amounts of Kr, Ar, or Xe are detectable in the YPtBi layer, wherein the YPtBi layer contains about 1% or less of Kr, Ar, or Xe. When forming the YPtBi layer, a target comprising one or more of the following can be used: Y, Bi, and Pt; YPtBi; YPt and Bi; PtBi and Y; or YBi and Pt. In embodiments using two targets to form the YPtBi layer, different amounts of power can be applied to each target. The 1:1:1 stoichiometric ratio of YPtBi results in a high spin Hall angle during operation.

[0024] Figure 1 This is a schematic diagram of some embodiments of a magnetic media drive 100 including a magnetic recording head with an SOT MTJ device. Such a magnetic media drive may be a single drive or include multiple drives. For illustration, a single disk drive 100 is shown according to some embodiments. As shown, at least one rotatable disk 112 is supported on a spindle 114 and rotated by a drive motor 118. Magnetic recording on each disk 112 is in the form of any suitable pattern of data tracks, such as a toroidal pattern of concentric data tracks (not shown) on the disk 112.

[0025] At least one slider 113 is positioned near the disk 112, and each slider 113 supports one or more head assemblies 121 including SOT devices. As the disk 112 rotates, the sliders 113 move radially in and out above the disk surface 122, allowing the head assemblies 121 to access different tracks of the disk 112 for writing desired data. Each slider 113 is attached to an actuator arm 119 via a suspension 115. The suspension 115 provides a slight spring force that biases the slider 113 toward the disk surface 122. Each actuator arm 119 is attached to an actuator device 127. Figure 2 The actuator component 127 shown may be a voice coil motor (VCM). The VCM includes a coil capable of moving within a fixed magnetic field, the direction and speed of which the coil moves are controlled by a motor current signal supplied by a control unit 129.

[0026] During operation of the disk drive 100, the rotation of the disk 112 creates an air bearing between the slider 113 and the disk surface 122, which applies an upward force or lift to the slider 113. Thus, during normal operation, the air bearing counteracts the slight spring force of the suspension 115 and supports the slider 113 away from and slightly above the disk surface 122 with a small, substantially constant gap.

[0027] Various components of the disk drive 100 are operated by control signals (such as access control signals and internal clock signals) generated by the control unit 129. The control unit 129 typically includes logic control circuitry, storage components, and a microprocessor. The control unit 129 generates control signals that control various system operations, such as drive motor control signals on line 123 and head position and seek control signals on line 128. The control signals on line 128 provide a desired current distribution to optimally move and position the slider 113 onto the desired data track on the disk 112. Write and read signals are transmitted through the recording channel 125 to and from the write and read heads on component 121.

[0028] The above description of typical magnetic media drivers and Figure 1 The accompanying illustrations are for illustrative purposes only. It should be apparent that a magnetic media drive may contain a large number of media or disks and actuators, and each actuator may support multiple sliders.

[0029] Figure 2 This is a partial cross-sectional side view of some embodiments of a read / write head 200 with an SOT device. The read / write head 200 faces the magnetic medium 112. The read / write head 200 may correspond to Figure 1 The described head assembly 121. The read / write head 200 includes a media-facing surface (MFS) 212 (such as a gas-bearing surface) facing the disk 112, the write head 210, and the magnetic read head 211. Figure 2 As shown, the magnetic medium 112 moves past the write head 210 in the direction indicated by arrow 232, and the read / write head 200 moves in the direction indicated by arrow 234.

[0030] In some embodiments, the magnetic read head 211 is a magnetoresistive (MR) read head having an MR sensing element 204 located between MR shields S1 and S2. In other embodiments, the magnetic read head 211 is an MTJ read head including a magnetic tunnel junction (MTJ) sensing device 204 disposed between MR shields S1 and S2. The magnetic field of adjacent magnetized regions in the disk 112 can be detected as a recording bit by the MR (MTJ) sensing element 204. SOT devices of various embodiments can be incorporated into the read head 211 as sensing elements. Examples of SOT read heads are described in Patent Application No. 17 / 828,226, which is assigned to the same assignee as this application and is incorporated herein by reference. Another example of a SOT readhead is described in co-pending patent application No. 18 / 367,877, entitled “Non-Localized Spin Valve Reader Hybridized With Spin Orbit Torque Layer,” filed September 13, 2023, and in co-pending patent application No. 18 / 367,882, entitled “Non-Localized Spin Valve Multi-Free-Layer Reader Hybridized With Spin Orbit Torque Layers,” filed September 13, 2023, which are incorporated herein by reference.

[0031] The write head 210 includes a center or master pole 220, a front shield 206, a rear shield 240, an optional spin-orbit torque (SOT) device 250, and a coil 218 that excites the master pole 220. The coil 218 may have a "pancake" structure, rather than... Figure 2The illustrated "spiral" structure, a "pancake-shaped" structure, is wound around the back contact between the main electrode 220 and the tail shield 240. For example, when included to achieve, for example, microwave-assisted magnetic recording (MAMR) effects, the SOT device 250 is formed in the gap 254 between the main electrode 220 and the tail shield 240. The main electrode 220 includes a tail cone 242 and a front cone 244. The tail cone 242 extends from a recessed position in the MFS 212. The front cone 244 extends from a recessed position in the MFS 212. The tail cone 242 and the front cone 244 may have the same taper and the taper is measured relative to the longitudinal axis 260 of the main electrode 220. In some embodiments, the main electrode 220 does not include the tail cone 242 and the front cone 244. Conversely, the main electrode 220 includes a tail side (not shown) and a front side (not shown), and the tail side and the front side are substantially parallel. The main electrode 220 may be a magnetic material, such as an FeCo alloy. The front shield 206 and the tail shield 240 may contain magnetic materials (such as a NiFe alloy). In some embodiments, the tail shield 240 may include a tail shield thermal seed layer 241. The tail shield thermal seed layer 241 may contain a high-torque sputtering material, such as CoFeN, FeXN, or FeX, wherein X includes at least one of N, Al, Ni, Co, Ta, Re, Ir, Pt, Rh, Ta, Zr, and Ti. In some embodiments, the tail shield 240 does not include a tail shield thermal seed layer.

[0032] Figures 3A and 3B illustrate spin-orbit torque (SOT) devices 300 and 350 according to various embodiments. SOT device 300 and SOT device 350 can be used individually. Figure 1 MAMR recording head of the 100-speed driver Figure 2 The reader and / or writer portion of the head 200, or other suitable magnetic media driver. SOT device 300 and SOT device 350 can each be individually a sensor or MRAM application (such as...). Figure 7 The MTJ in the example MRAM implementation disclosed herein, and the spin charge conversion layer / structure in logic circuits that can be used in artificial intelligence chips. Aspects of SOT device 300 and SOT device 350 can be combined with each other.

[0033] The SOT device 300 of Figure 3A includes a seed layer 302, a buffer layer 304 disposed above the seed layer 302, a first migration barrier layer 306 disposed above the buffer layer 304, a topological half-metal (TSM) layer 312 disposed on the first migration barrier layer 306, a sandwich layer 310 disposed on the TSM layer 312, a ferromagnetic (FM) layer 316 disposed on the sandwich layer 310, and a capping layer 318 disposed on the FM layer 316. The sandwich layer 310 includes a second migration barrier layer 308 disposed on the TSM layer 312 and a sub-sandwich layer 314 disposed on the second migration barrier layer 308. The first migration barrier layer 306 may contain a different material than the second migration barrier layer 308. In some embodiments, the second migration barrier layer 308 and the sub-sandwich layer 314 are considered to be separate layers rather than the sandwich layer 310. The buffer layer 304 may have a (100) orientation, a (111) orientation, or a (110) orientation. In some implementations, the buffer layer 304 includes a first migration barrier layer 306.

[0034] The SOT device 350 of Figure 3B includes a seed layer 302, an FM layer 316 disposed on the seed layer 302, a mezzanine layer 310 disposed on the FM layer 316, a TSM layer 312 disposed on the mezzanine layer 310, a first migration barrier layer 306 disposed on the TSM layer 312, a buffer layer 304 disposed on the first migration barrier layer 306, and a capping layer 318 disposed on the buffer layer 304. The mezzanine layer 310 includes a sub-mezzanine layer 314 disposed on the FM layer 316 and a second migration barrier layer 308 disposed between the sub-mezzanine layer 314 and the TSM layer 312. The first migration barrier layer 306 may contain a different material than the second migration barrier layer 308. The sub-mezzanine layer 314 may have a (100) orientation, a (110) orientation, or a (111) orientation. In some embodiments, the buffer layer 304 includes the first migration barrier layer 306.

[0035] In both SOT devices 300 and 350, the first migration barrier layer 306 and the second migration barrier layer 308 are configured to contact the TSM layer 312, such that the TSM layer 312 is sandwiched between the first migration barrier layer 306 and the second migration barrier layer 308. The buffer layer 304, the interlayer 310, and the capping layer 318 promote symmetrical epitaxial crystal growth of the TSM layer 312 while minimizing shunt. The migration barrier layers 306 and 308 further facilitate epitaxial growth and, due to minimal chemical interactions, prevent diffusion out of the TSM layer 312 and prevent material from diffusing from the buffer layer 304, the interlayer 310, and the capping layer 318 into the TSM layer 312.

[0036] TSM layer 312 contains YPtBi with either a (100) or (110) orientation. The YPtBi has a stoichiometric ratio of 1:1:1 and a density between about 9.7 g / cc and about 11.2 g / cc, such as about 11 g / cc or greater. The YPtBi in TSM layer 312 may contain trace, detectable amounts of Kr, such as about 1% or less of Kr. TSM layer 312 containing YPtBi with a 1:1:1 stoichiometric ratio achieves the highest spin Hall angle during operation. The method for achieving this high density is described below. Figures 4A to 5B In the middle. The TSM layer 312 has a thickness of about 100 Å to about 140 Å (such as about 120 Å) in the y direction.

[0037] The first migration barrier layer 306 may contain a different material than the second migration barrier layer 308. The first migration barrier layer 306 and the second migration barrier layer 308 not only effectively reduce element migration, but they are also typically high-resistivity layers, reducing interlayer current shunting and acting to transfer (100) or (110) epitaxial growth from one layer to the next, or to the topological SOT layer, thereby reducing interface roughness. The barrier layers may be selected from three different groups of non-magnetic materials.

[0038] The first group of materials used for barrier layer 306 and barrier layer 308 includes the following options: (1) B2 (AB) binary alloys with high lattice parameters, high electrical resistance, and atomically ordered stoichiometry, such as RuHf alloys and Zr-X alloys, wherein X is one or more of Co, Cu, Ru and Rh; (2) Ti-Y alloys, wherein Y is one or more of Au, Ru and Rh; or (3) B2 ternary A (BxC1-x) alloys with stoichiometry, such as (HfTi).5Ru, Ru(AlV).5, (AlMo).5Ti and CoZrX, wherein X is one or more of Ti, Fe, Ni, Nb and Mo (examples include Co(Ti.3Zr.7), (Co.8Fe.2)Zr, (CoNi).5Zr, Co(Nb.25Zr.75)). Barrier layers 306 and 308 may also be disordered, non-stoichiometric binary, ternary, or more elemental bcc alloys, wherein multiple elements are selected from the group consisting of Ta, Hf, W, Ir, Pt, Y, Zr, Nb, Mo, Mg, Sc, Ti, V, Cr, Fe, Co, Ni, Cu, Ru, Rh, and Ag, wherein all of these elements have lattice parameters in the range of 2.87 Å to 3.38 Å.

[0039] The second material group used for barrier layer 306 and barrier layer 308 is an fcc material having a lattice parameter of about 4.08 Å to 4.75 Å, such as oxides of Ti, Mg, Ni, Zn or Zr; or an XN or XC composite material, wherein X is one or more of Sc, Ti, V, Cr, Zr, Nb, Ta, Hf and W, and alloy composites of the above.

[0040] The third group of materials used for barrier layers 306 and 308 are tetragonal oxides, such as MO2 materials, having an a-axis lattice parameter in the range of 4.35 Å to 4.75 Å and a c-axis lattice parameter in the range of 2.85 Å to 3.19 Å. Examples of such materials include those in which M is one of the following: Ti, Cr, Ru, Rh, Sn, Sb or Ir; or alloys of CrNb, CrV and WV; or any combination thereof.

[0041] The first two barrier layer material groups can be used with either a (100) textured layer or a (110) textured layer to form (100) textured barrier layer 306, (100) textured barrier layer 308, or (110) textured barrier layer 306, (110) textured barrier layer 308. The texturing of the third barrier layer material group (i.e., MO2 tetragonal oxide) will depend on the type of textured layer. For a (100) textured layer, MO2 tetragonal oxide will produce (001) textured MO2 tetragonal oxide, which can then be used to produce (100) textures in other layers. For the (110) textured layer, the MO2 tetragonal oxide will produce a (110) textured tetragonal MO2 oxide layer, but only for oxides with an a / c ratio close to sqrt(2), such as oxides where M is Os, Ir, Ru, Rh, or Pd. The first migration barrier layer 306 may contain a different material than the second migration barrier layer 308. Each barrier layer 306 and barrier layer 308 may include one or more barrier layers, depending on the application used to optimize the growth, electroshunting, or element migration characteristics between layers.

[0042] Seed layer 302 comprises an amorphous or nanocrystalline material. Seed layer 302 may include a laminated structure comprising one or more materials selected from the group consisting of NiTa, RuAl, MgO, MgTiO, CrMo, CoFeTa, NiFeGe, NiFeTa, NiW, Ru, IrAl, and combinations thereof. Seed layer 302 has a thickness of about 10 Å to about 30 Å (such as about 20 Å) in the y-direction.

[0043] Buffer layer 304 may comprise a combination of materials selected from the group consisting of (100) textured layers or (110) textured layers or mixtures thereof, wherein the group consisting of (a)-(k) is listed below: (a) bcc metals or alloys having a-axis lattice parameters in the range of 2.9 Å to about 3.4 Å, such as Ta, W, Mo, Nb, WTi, and CrMo; (b) B2 metals having the same range of lattice parameters, such as binary alloys of RuAl, RuHf, Zr-X alloys (where X is one or more of Co, Cu, Ru, and Rh) or Ti-Y alloys (where Y is one or more of Au, Ru, and Rh); (c) B2 ternary alloys, such as HfRuTi, RuAlV, AlTiMo and CoZrX, wherein X is Ti, Fe, Ni, Nb and Mo, or one or more of any combination thereof; (d) (100) textured fcc materials and (110) textured fcc materials, such as oxides of Ti, Mg, Ni, Zn and Zr, XN or XC composites, wherein X is Sc, Ti, V, Cr, Zr, Nb, Ta, Hf and W, and alloy composites thereof, having a lattice parameter of about 4.08 Å to about 4.75 Å; (e) (001) textured tetragonal oxides, such as MO2 materials, having an a-axis lattice parameter in a range similar to the above range, wherein M is Ti, Cr, Ru, Rh, Sn, Sb and Ir, or one or more of their alloy composites; (f) (110) textured tetragonal MO2, wherein the a / c ratio is close to sqrt(2), such as where M It is one or more of Os, Ir, Ru, Rh, Sn, Sb and Pd; (g) a half-metal or all-metal with a high lattice parameter fcc in the range of 5.9 Å to 6.7 Å; (110) a textured Heusler alloy or (100) a textured Heusler alloy, such as MnSbPt (6.20 Å) or Sc2VGe (a=6.65 Å) and Pd2SnY (6.70 Å); (h) having space group 216 and similar. Other spinel cubic materials with lattice parameters, such as YNiBi, YPdBi, NiBiGd, AgMgSb and BiXPt (where X is a rare earth element from Gd to Lu); (i) (100) textured layer materials, such as X-Al, where X is one or more of Co, Ni, Ru, Rh and Ir; (j) heated Cr or CrX alloys, where X is one or more of Mo, Mn, Ti, Ru and W; and (k) combinations thereof.

[0044] Those skilled in the art can use a combination of nanocrystalline conditioning layers and other bcc seed layer materials; alloy seed layer films (such as the Cr-X alloy mentioned above); or by using thin (001)hcp Ru seeds to grow bcc metal along a close-packing direction, thereby producing the aforementioned strongly (110) textured bcc or bcc alloy films with lattice parameters in the range of 2.9 Å to 3.4 Å. These highly textured (110) bcc or bcc alloy films can then be used to grow fcc (110) textured buffer layer films with the aforementioned lattice parameters of about 4.08 Å to 4.75 Å; the aforementioned (110) textured binary or ternary or more elemental B2 alloys; or high lattice parameter fcc Hessler or spinel with lattice parameters in the range of about 5.9 Å to 6.7 Å mentioned above, which can be used as high-resistivity or migration buffer layers on which (110) textured YPtBi SOT layers can be grown. As mentioned above, the (110) textured buffer layer of MO2 oxide can also be used for those oxides with an a / c ratio close to sqrt(2).

[0045] Those skilled in the art can also grow bcc metals or B2 materials and alloys with strong (100) textures and lattice parameters in the range of about 2.9 Å to 3.4 Å, similar to the RuAl or heated Cr-X alloys mentioned above. These (100) textured layers can be used to grow strong fcc (100) textured buffer layers with lattice parameters in the range of 4.08 Å to 4.75 Å mentioned above; (100) textured Hessler alloys or spinel-type structures with lattice parameters in the range of 5.9 Å to 6.75 Å mentioned above; or (001) textured MO2 tetragonal oxides with axial lattice parameters in the range of 4.1 Å to 4.75 Å mentioned above.

[0046] Typically, a buffer layer located between the textured seed layer and the SOT layer can provide better control over the electrical shunting between the seed layer and the SOT layer, or serve as a migration barrier layer to prevent the SOT layer and the seed layer from mixing, or provide better epitaxial growth for the YPtBi or BiSbX SOT layer.

[0047] FM layer 316 has a thickness of about 5 Å to about 15 Å and may contain NiFe, CoFe, NiFeX, CoFeX, FeX, or NiX, where X is one or more of Co, Ni, Cu, Si, Al, Mn, Ge, Ta, Hf, or B. FM layer 316 may contain any combination of magnetic layers or alloys of these elements that produce low coercivity, negative magnetostriction FM layer 316, or a multilayer combination with other higher polarization materials (such as Hessler alloys or high-Ni alloy FM layers). Sub-layer 314 may contain MgO, CoFeB, Co, CoFe, NiFe, or a material similar to FM layer 316. Sub-layer 314 and interlayer 310 together have a thickness of about 20 Å or less in the y-direction.

[0048] The capping layer 318 may comprise a non-magnetic, high-resistivity material, such as: thin ceramic oxides or nitrides of TiN, SiN, MgTiO, and MgO; amorphous / nanocrystalline metals, such as NiFeTa, NiTa, NiHf, NiFeHf, CoHf, CoFeHf, NiWTa, NiFeW, NiW, WRe; or nitrides, oxides, or borides of the elements mentioned above, compounds, and / or alloys such as NiTaN, NiFeTaN, NiWTaN, NiWN, WReN, TaN, WN, TaOx, WOx, WB, HfB, NiHfB, NiFeHfB, CoHfB, and CoFeHfB, where x is a number. In some embodiments, a material with a lower atomic number (Z) is preferably used in the capping layer 318 to reduce sputtering intermixing with the FM layer 316. High-Z alloys may be used in the following cases: when combined with the migration barrier layer below, or when the high-Z element is used with high-resistivity oxides, nitrides, or borides. The capping layer 318 may comprise a multilayer combination of materials as mentioned above, and the overall thickness of the capping layer 318 is less than or equal to about 100 Å (nominal about 15 Å to about 50 Å).

[0049] Figures 4A to 4C Methods 400, 430, and 450 according to various embodiments for forming YPtBi with a 1:1:1 composition are shown respectively. Methods 400, 430, and 450 can each be used to generate the TSM layer 312 of FIG3A to FIG3B.

[0050] exist Figure 4A In method 400, at block 402, a substrate is loaded onto a chuck heated to a temperature of approximately 300°C to approximately 600°C in a deposition chamber. The deposition chamber can be any known deposition chamber, such as a physical vapor deposition (PVD) chamber.

[0051] At box 404, one of the following target combinations is placed in the deposition chamber: 1) a YPt target and a Bi target; 2) a YBi target and a Bi target; or 3) a PtBi target and a Y target. Due to the preferential sputtering of Bi, the target may not be a 50 / 50 target. Therefore, the target may contain less than about 50% Bi. At box 406, the Kr, Ar, or Xe gas flow rate, pressure, and substrate bias are adjusted within the deposition chamber. The Kr, Ar, or Xe gas flow rate can be from about 25 sccm to about 55 sccm, such as about 40 sccm. The pressure can be from about 0.2 mTorr to about 20 mTorr, or about 0.2 mTorr or less, while maintaining a stable plasma. The substrate bias can be from about 20 V to about 200 V, such as about 50 V ± 25 V.

[0052] At frame 408, power and a Kr, Ar, or Xe gas are applied to a selected target to sputter the target onto the substrate to form a film comprising YPtBi having a stoichiometric ratio or composition of 1:1:1. Different power levels can be applied to each target during sputtering. For example, when both a YPt and a Bi target are selected, a first power of about 90 W to about 200 W can be used when sputtering the YPt target, while a second power of about 20 W to about 50 W can be used when sputtering the Bi target. In some embodiments, the power applied to the Bi target is about 20% to about 30% of the power applied to the YPt target, or the ratio of the YPt target to the Bi target is about 5:1.

[0053] By utilizing different power levels and adjusting the flow rates of Kr, Ar, or Xe gases, YPtBi films can achieve a stoichiometry of 1:1:1 and a high density between about 9.7 g / cc and about 11.2 g / cc. In some embodiments, the density of the YPtBi film is greater than about 11 g / cc. Furthermore, trace amounts of Kr can be detected in the finished film. For example, about 0.5 atomic% to about 2.0 atomic% of Kr, Ar, or Xe can be detected as dopants.

[0054] exist Figure 4B In method 430, at block 432, a substrate is loaded onto a chuck heated to a temperature of approximately 300°C to approximately 600°C in a deposition chamber. The deposition chamber can be any known deposition chamber, such as a physical vapor deposition (PVD) chamber.

[0055] At box 434, Y, Pt, and Bi targets are placed in the deposition chamber. At box 436, the gas flow rate, pressure, and substrate bias within the deposition chamber are adjusted. The gas flow rate can be from about 25 sccm to about 55 sccm, such as about 40 sccm. The pressure can be from about 0.2 mTorr to about 20 mTorr, or about 0.2 mTorr or less, while maintaining a stable plasma. The substrate bias can be from about 20 V to about 200 V, such as about 50 V ± 25 V. At box 438, power and Kr, Ar, or Xe gas are applied to the Y, Pt, and Bi targets to sputter the targets onto the substrate to form a film comprising YPtBi with a 1:1:1 stoichiometric ratio or composition. Different power levels can be applied to each target during sputtering. For example, when sputtering a Y target, a first power of about 100W to about 500W (such as about 115W to about 125W) can be used; when sputtering a Bi target, a second power of about 20W to about 300W (such as about 25W to about 30W) can be used; and when sputtering a Pt target, a third power of about 20W to about 500W can be used. In some embodiments, the power applied to the Pt target is about 20% to about 30% of the power applied to the YBi target.

[0056] By utilizing different power levels and adjusting the flow rates of Kr, Ar, or Xe gases, YPtBi films can achieve a stoichiometry of 1:1:1 and a high density between about 9.7 g / cc and about 11.2 g / cc. In some embodiments, the density of the YPtBi film is greater than about 11 g / cc. Furthermore, trace amounts of Kr can be detected in the finished film. For example, about 0.1 atomic% to about 2.5 atomic% of Kr, Ar, or Xe can be detected as dopants.

[0057] exist Figure 4C In method 450, at block 452, a substrate is loaded onto a chuck heated to a temperature of approximately 300°C to approximately 600°C in a deposition chamber. The deposition chamber can be any known deposition chamber, such as a physical vapor deposition (PVD) chamber.

[0058] At box 454, a YPtBi target is placed in the deposition chamber. For example, to form the YPtBi target, the following amounts can be used: approximately 10 g to approximately 15 g of Y, approximately 20 g to approximately 30 g of Pt, and approximately 20 g to approximately 40 g of Bi. At box 456, the gas flow rate, pressure, and substrate bias within the deposition chamber are adjusted. The gas flow rate can be approximately 25 sccm to approximately 55 sccm, such as approximately 40 sccm. The pressure can be approximately 0.2 mTorr to approximately 20 mTorr, or approximately 0.2 mTorr or less, while maintaining a stable plasma. The substrate bias can be approximately 20 V to approximately 200 V, such as approximately 50 V ± 25 V.

[0059] At frame 458, power and a Kr, Ar, or Xe gas are applied to a YPtBi target to sputter the target onto the substrate to form a film comprising YPtBi having a 1:1:1 stoichiometry or composition. The power applied to the YPtBi target can be from about 20 W to about 500 W. Adjusting the power level and gas flow rate allows the YPtBi film to achieve a 1:1:1 stoichiometry and a high density between about 9.7 g / cc and about 11.2 g / cc. In some embodiments, the density of the YPtBi film is greater than about 11 g / cc. Furthermore, trace amounts of Kr, Ar, or Xe can be detected in the finished film. For example, about 0.1 atomic% to about 2.5 atomic% of Kr, Ar, or Xe can be detected as dopants.

[0060] Figure 5A A graph 500 is shown according to one embodiment, which shows that, in order to read a 1:1:1 composition, the power ratio between the power (W) applied to the Bi target and the power (W) applied to the YPt target is fixed. Figure 5B A graph 550 is shown according to one embodiment, illustrating the stoichiometry of YPt difference between Pt and Y in a sputtered YPtBi film, controlled by the Kr gas flow rate (sccm). While graphs 500 and 550 correspond to those using YPt and Bi targets respectively... Figure 4A Method 400, but these charts are intended only as examples and can be applied to... Figures 4B to 4C Methods 430 and 450. Kr gas is used as an example, but the gas could also be Ar or Xe.

[0061] As shown in Tables 500 and 550, when YPtBi films are deposited at a Kr gas flow rate of about 40 sccm, and power of about 20 W to about 45 W is applied to the Bi target and power of about 90 W to about 200 W is applied to the YPt (50 / 50) target, the resulting YPtBi with a stoichiometric ratio of 1:1:1 achieves a high density between about 9.7 g / cc and about 11.2 g / cc.

[0062] As also shown in Figure 550, when the Kr gas flow rate is between about 15 sccm and about 55 sccm (e.g., about 15 sccm), when the power from Bi and YPt in Figure 500 is applied to the Bi target and the YPt target respectively, a 1:1 relative Y to Pt stoichiometry is achieved in the YPtBi film with a non-stoichiometric YPt (49 / 51) target (±2%Δ).

[0063] Figure 6A In MAMR magnetic recording heads such as Figure 1 A schematic cross-sectional view of an SOT device 600 used in a MAMR magnetic recording head of a driver 100 or other suitable magnetic media driver. The SOT device 600 includes a TSM layer 312 oriented such as the TSM layer 312 and buffer layer 304 of FIG. 3A or the TSM layer 312 and buffer layer 304 of FIG. 3B, formed over a buffer layer 304 (which is formed over a substrate 601). Thus, the TSM layer 312 may contain YPtBi with a (100) orientation or YCtBi with a (110) orientation. A spin torque layer (STL) 670 is formed over the TSM layer 312. The STL 670 contains a ferromagnetic material, such as one or more layers of CoFe, CoIr, NiFe, and CoFeX alloys, where X = B, Ta, Re, or Ir.

[0064] In some embodiments, a current shunt blocking layer 660 is disposed between the TSM layer 312 and the STL 670. The current shunt blocking layer 660 reduces the current flowing from the TSM layer 312 to the STL 670, but allows spin-orbit coupling between the TSM layer 312 and the STL 670. In some embodiments, the current shunt blocking layer 660 comprises a magnetic material that provides greater spin-orbit coupling between the TSM layer 312 and the STL 670 compared to a non-magnetic material. In some embodiments, the current shunt blocking layer 660 comprises a magnetic material of FeCo, FeCoM, FeCoMO, FeCoMMeO, FeCoM / MeO stack, FeCoMNiMnMgZnFeO, FeCoM / NiMnMgZnFeO stack, multiple layers / stacks thereof, or combinations thereof, wherein M is one or more of B, Si, P, Al, Hf, Zr, Nb, Ti, Ta, Mo, Mg, Y, Cu, Cr, and Ni. Me is one or more of Si, Al, Hf, Zr, Nb, Ti, Ta, Mg, Y, or Cr. In some embodiments, the current shunt blocking layer 660 is formed with a thickness of about 10 Å to about 100 Å. In some aspects, a current shunt blocking layer 660 with a thickness greater than 100 Å can reduce the spin-orbit coupling between the TSM layer 312 and the STL 670. In some aspects, a current shunt blocking layer with a thickness less than 10 Å may not be sufficient to reduce the current from the TSM layer 312 to the STL 670.

[0065] In some embodiments, additional layers, such as spacer layer 680 and pinning layer 690, are formed above STL 670. Pinning layer 690 may partially pin STL 670. Pinning layer 690 comprises one or more layers of PtMn, NiMn, IrMn, IrMnCr, CrMnPt, FeMn, other antiferromagnetic materials, or combinations thereof. Spacer layer 680 comprises one or more layers of magnesium oxide, aluminum oxide, other nonmagnetic materials, or combinations thereof.

[0066] Figures 6B to 6C It has Figure 6A A schematic MFS view of some embodiments of a portion of the MAMR magnetic recording head 210 of an SOT device 600. The MAMR magnetic recording head 210 may be... Figure 2 magnetic recording head or Figure 1 The MAMR magnetic recording head 210 is a drive 100 or another suitable magnetic media drive, such as a magnetic tape drive. The MAMR magnetic recording head 210 includes a master pole 220 and a tail shield 240 along the track direction. An SOT device 600 is disposed in the gap between the master pole and the tail shield 240.

[0067] While MRAM device 600 generally corresponds to the top SOT embodiment of FIG. 3B, other MRAM implementations (where the layers of MRAM device 600 are reversed) may correspond to or conform to the bottom SOT embodiment of FIG. 3A. TSM layer 312, RL 610, and buffer layer 302 in FIG. 6 may correspond to various layer configurations in FIG. 3A through FIG. 3B. For example, TSM layer 312 may correspond to TSM layer 312. Thus, TSM layer 312 may contain YPtBi with a (100) orientation or YCtBi with a (110) orientation. RL 610 may correspond to FM layer 316. Buffer layer 304 may correspond to buffer layer 304.

[0068] During operation, a spin current is generated in the BiSb layer by the charge current of the TI layer or layer stack 312, which acts as a spin Hall layer. Spin-orbit coupling between the BiSb layer and the spin-torque layer (STL) 670 causes switching or precession of the magnetization of the STL 670 through spin-orbit coupling from the spin current of the TSM layer 312. This switching or precession of the STL 670's magnetization can generate an auxiliary AC electric field to the write field. Compared to spin-torque-based MAMR magnetic recording heads, the SOT-based energy-assisted magnetic recording head has several times the power efficiency. Figure 6B As shown, due to the anisotropic shape of the STL 670, due to... Figure 6A The pinning layer 690 and / or the hard bias element near the STL 670 cause the easy magnetization axis of the STL 670 to be perpendicular to the MFS. For example... Figure 6C As shown, due to the anisotropic shape of the STL 670, due to... Figure 6A The pinning layer 690 and / or the complex biasing element close to the STL 670 cause the easy magnetization axis of the STL 670 to be parallel to the MFS.

[0069] Figure 7 This is a schematic cross-sectional view of an SOT MTJ 701 used as an MRAM device 700. The MRAM device 700 includes a reference layer (RL) 710, a spacer layer 720 above the RL 710, a recording layer 730 above the spacer layer 720, a buffer layer 704 above a current shunt barrier layer 740 above the recording layer 730, and a TSM layer or layer stack 312 above the buffer layer 304. The TSM layer 312 and buffer layer 304 can be the TSM layer 312 and buffer layer 304 of FIG. 3A or the TSM layer 332 and buffer layer 360 of FIG. 3B. Therefore, the TSM layer 312 can contain YPtBi with a (100) orientation or YCtBi with a (110) orientation.

[0070] RL 710 comprises one or more layers of CoFe, other ferromagnetic materials, or combinations thereof. Spacer layer 720 comprises one or more layers of magnesium oxide, aluminum oxide, other dielectric materials, or combinations thereof. Recording layer 730 comprises one or more layers of CoFe, NiFe, other ferromagnetic materials, or combinations thereof.

[0071] As noted above, in some embodiments, a current shunt blocking layer 740 is disposed between the buffer layer 304 and the recording layer 730. The current shunt blocking layer 740 reduces the current flowing from the TSM layer 312 to the recording layer 730. The current shunt blocking layer 740 still allows spin-orbit coupling between the TSM layer 312 and the recording layer 730. For example, writing to an MRAM device can be achieved through spin-orbit coupling between the TSM layer and the recording layer 730, which allows the magnetization of the recording layer 730 to be switched via spin-orbit coupling from the spin current of the TSM layer 312. In some embodiments, the current shunt blocking layer 740 comprises a magnetic material that provides greater spin-orbit coupling between the TSM layer 312 and the recording layer 730 compared to a non-magnetic material. In some embodiments, the current shunt blocking layer 740 comprises a magnetic material of FeCoM, FeCoMO, FeCoMMeO, FeCoM / MeO stack, FeCoMNiMnMgZnFeO, FeCoM / NiMnMgZnFeO stack, multiple layers / stacks thereof, or combinations thereof, wherein M is one or more of B, Si, P, Al, Hf, Zr, Nb, Ti, Ta, Mo, Mg, Y, Cu, Cr, and Ni; and Me is Si, Al, Hf, Zr, Nb, Ti, Ta, Mg, Y, or Cr.

[0072] Figure 7 The MRAM device 700 may include other layers, such as pinning layers, pinning structures (e.g., synthetic antiferromagnetic (SAF) pinning structures), electrodes, gates, and other structures. Other MRAM devices besides the structure of FIG. 6 may be formed using the TSM layer 312 located above the buffer layer 304 to form the SOT MTJ 701.

[0073] Therefore, a high spin Hall angle can be achieved in SOT devices by utilizing YPtBi films with a stoichiometric ratio of 1:1:1 and a density of approximately 9.7 g / cc to approximately 11.2 g / cc.

[0074] In one embodiment, the spin orbital torque (SOT) device includes a YPtBi layer having a stoichiometric ratio of 1:1:1 and a density between about 9.7 g / cc and about 11.2 g / cc.

[0075] The YPtBi layer comprises about 0.1 atomic% to about 2.5 atomic% of Kr, Ar, or Xe. The YPtBi layer has a (100) orientation, a (111) orientation, or a (110) orientation. The SOT device also includes a buffer layer disposed adjacent to the YPtBi layer. The buffer layer comprises a material selected from the group consisting of: X-Al, wherein X is one or more of Co, Ni, Ru, Rh, and Ir; Cr or CrX alloys, wherein X is one or more of Mo, Mn, Ti, Ru, and W; and RuAl, WX, or Ta-X alloys with MgO and TiO, wherein X is one or more of Ta, Hf, W, V, Ti, Nb, and Mo. The buffer layer comprises a material selected from the group consisting of: RuHf; Zr-X alloy, wherein X is one or more of Co, Cu, Ru, and Rh; Ti-Y alloy, wherein Y is one or more of Au, Ru, and Rh; B2 ternary A (BxC1-x) alloy; B2 binary alloy; CoZrX, wherein X is one or more of Ti, Fe, Ni, Nb, and Mo; two or more elements selected from the group consisting of: Ta, Hf, W, Ir, Pt, Y, Zr, Nb, Mo, Mg, Sc, Ti, V, Cr, Fe, Co, Ni, Cu, Ru, Rh, and Ag; oxides of Ti, Mg, Ni, Zn, or Zr; XN or XC composite material, wherein X is one or more of Sc, Ti, V, Cr, Zr, Nb, Ta, Hf, and W; and MO2 material, wherein M is one or more of Ti, Cr, Ru, Rh, Sn, Sb, Ir, CrNb, CrV, and WV. A magnetic recording head including the SOT device. A magnetic recording device including magnetic recording. A magnetoresistive memory including the SOT device.

[0076] In another embodiment, a method for forming a YPtBi film having a 1:1:1 stoichiometric ratio includes: loading a substrate onto a chuck heated to about 300°C to about 600°C in a deposition chamber; placing a YPt target and a Bi target in the deposition chamber; adjusting the flow rate, pressure, and substrate bias of a Kr, Ar, or Xe gas in the deposition chamber; and applying power and the Kr, Ar, or Xe gas to sputter the YPt target and the Bi target to form a film comprising a YPtBi film having a 1:1:1 stoichiometric ratio.

[0077] A first power is applied to sputter a YPt target, and a second power is applied to sputter a Bi target. The first power is greater than the second power. The second power is about 20% to about 30% of the first power. The flow rate of the Kr, Ar, or Xe gas is about 20 sccm to about 50 sccm. The YPtBi film with a 1:1:1 stoichiometric ratio has a density between about 9.7 g / cc and about 11.2 g / cc. A spin-orbit torque (SOT) device includes a YPtBi film with a 1:1:1 stoichiometric ratio formed by this method.

[0078] In yet another embodiment, a method for forming a YPtBi film having a stoichiometric ratio of 1:1:1 includes: loading a substrate onto a chuck heated to about 300°C to about 600°C in a deposition chamber; placing one of the following target combinations in the deposition chamber: 1) a YBi target and a Pt target; 2) a PtBi target and a Y target; or a Y target, a Pt target, and a Bi target; adjusting the Kr, Ar, or Xe gas flow rate, pressure, and substrate bias of the deposition chamber; and applying power and Kr, Ar, or Xe gas to sputter the YBi target and the Pt target to form a film comprising a YPtBi film having a stoichiometric ratio of 1:1:1.

[0079] The pressure is from about 0.2 mTorr to about 20 mTorr. The substrate bias is from about 25 V to about 75 V. The Kr, Ar, or Xe gas flow rate is from about 20 sccm to about 50 sccm. The YPtBi film with a 1:1:1 stoichiometric ratio has a density between about 9.7 g / cc and about 11.2 g / cc. The spin-orbit torque (SOT) device includes a YPtBi film with a 1:1:1 stoichiometric ratio formed by this method.

[0080] While the foregoing content pertains to embodiments of this disclosure, other and additional embodiments of this disclosure may be contemplated without departing from the essential scope of this disclosure, which is defined by the appended claims.

Claims

1. A spin-orbit torque (SOT) device, the SOT device comprising: A YPtBi layer having a stoichiometric ratio of 1:1:1, the YPtBi layer having a density between about 9.7 g / cc and about 11.2 g / cc.

2. The SOT device of claim 1, wherein the YPtBi layer comprises about 0.1 atomic% to about 2.5 atomic% of Kr, Ar or Xe.

3. The SOT device according to claim 1, wherein the YPtBi layer has a (100) orientation, a (111) orientation, or a (110) orientation.

4. The SOT device according to claim 1, wherein the SOT device further comprises a buffer layer disposed adjacent to the YPtBi layer.

5. The SOT device of claim 4, wherein the buffer layer comprises a material selected from the group consisting of: X-Al, where X is one or more of Co, Ni, Ru, Rh and Ir; Cr or CrX alloys, wherein X is one or more of Mo, Mn, Ti, Ru, and W; and Alloys of RuAl, WX, or Ta-X with MgO and TiO, wherein X is one or more of Ta, Hf, W, V, Ti, Nb, and Mo.

6. The SOT device of claim 4, wherein the buffer layer comprises a material selected from the group consisting of: RuHf; Zr-X alloy, wherein X is one or more of Co, Cu, Ru and Rh; Ti-Y alloy, wherein Y is one or more of Au, Ru and Rh; B2 ternary A (BxC1-x) alloy; B2 binary alloy; CoZrX, where X is one or more of Ti, Fe, Ni, Nb and Mo; Choose two or more elements from the following groups: Ta, Hf, W, Ir, Pt, Y, Zr, Nb, Mo, Mg, Sc, Ti, V, Cr, Fe, Co, Ni, Cu, Ru, Rh, and Ag; Oxides of Ti, Mg, Ni, Zn or Zr; XN or XC composite materials, wherein X is one or more of Sc, Ti, V, Cr, Zr, Nb, Ta, Hf, and W; and MO2 material, wherein M is one or more of Ti, Cr, Ru, Rh, Sn, Sb, Ir, CrNb, CrV and WV.

7. A magnetic recording head, the magnetic recording head comprising the SOT device according to claim 1.

8. A magnetic recording device, the magnetic recording device comprising the magnetic recording head according to claim 7.

9. A magnetoresistive memory, the magnetoresistive memory comprising the SOT device according to claim 1.

10. A method for forming a YPtBi film having a stoichiometric ratio of 1:1:1, the method comprising: The substrate is loaded into a chuck in the deposition chamber and heated to a temperature of approximately 300°C to approximately 600°C. YPt and Bi targets are placed in the deposition chamber; Adjust the Kr, Ar, or Xe gas flow rate, pressure, and substrate bias in the deposition chamber; as well as Power and Kr, Ar or Xe gas are applied to sputter the YPt target and the Bi target to form a film comprising a YPtBi film having a stoichiometric ratio of 1:1:1 and a density between about 9.7 g / cc and about 11.2 g / cc.

11. The method of claim 10, wherein a first power is applied to sputter the YPt target, and a second power is applied to sputter the Bi target.

12. The method of claim 11, wherein the first power is greater than the second power.

13. The method of claim 11, wherein the second power is 20% to 30% of the first power.

14. The method of claim 10, wherein the Kr, Ar, or Xe gas flow rate is from about 20 sccm to about 50 sccm.

15. A spin orbital torque (SOT) device, the SOT device comprising a YPtBi film having a stoichiometric ratio of 1:1:1 formed by the method according to claim 10.

16. A method for forming a YPtBi film having a stoichiometric ratio of 1:1:1, the method comprising: The substrate is loaded into a chuck in the deposition chamber and heated to a temperature of approximately 300°C to approximately 600°C. Place one of the following target combinations in the deposition chamber: YBi and Pt targets; PtBi and Y targets; or Y-targets, Pt-targets, and Bi-targets; Adjust the Kr, Ar, or Xe gas flow rate, pressure, and substrate bias in the deposition chamber; and Power and Kr, Ar, or Xe gas are applied to sputter the YBi target and the Pt target to form a film comprising a YPtBi film having a stoichiometric ratio of 1:1:1 and a density between about 9.7 g / cc and about 11.2 g / cc.

17. The method of claim 16, wherein the pressure is from about 0.2 mTorr to about 20 mTorr.

18. The method of claim 16, wherein the substrate bias is from about 25V to about 75V.

19. The method of claim 16, wherein the Kr, Ar, or Xe gas flow rate is from about 20 sccm to about 50 sccm.

20. A spin orbital torque (SOT) device, the SOT device comprising a YPtBi film having a stoichiometric ratio of 1:1:1 formed by the method according to claim 16.

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