Nitrogen-doped oxides for reducing bandgap

Abstract

Nitrogen doping of the insulating layer can lower the bandgap of the magnetic memory device. Nitrogen doping of magnesium oxide (MgO) is challenging. Cations can be added to allow the magnesium to remain on the nitrogen dopant without highly oxidizing or nitriding the cation. The resulting nitrogen-doped MgXO (where X is the cation) has a lower bandgap than very similar barrier layers that have neither nitrogen nor cations, improving thermal and electrical reliability. The nitrogen-doped MgXO is non-stoichiometric, while oxynitrides are stoichiometric, relatively speaking. Example cations that can be used include aluminum, titanium, vanadium, chromium, and scandium.

Description

[0001] Cross-references to related applications

[0002] This application claims the benefit and priority of U.S. Nonprovisional Application Serial No. 18 / 407,553, filed on January 9, 2024. Background Technology Summary of the Invention

[0004] Nitrogen doping of the insulating layer can reduce the band gap of magnetic storage devices. Nitrogen-doped magnesium oxide (MgO) is challenging. Cations can be added to allow magnesium to remain on the nitrogen dopant without highly oxidizing or nitriding the cations. The resulting nitrogen-doped MgXO (where X is a cation) has a lower band gap compared to a very similar barrier layer that has neither nitrogen nor cations, thus improving thermal and electrical reliability. Nitrogen-doped MgXO is non-stoichiometric, whereas nitrogen oxides are stoichiometric. Example cations that can be used include aluminum, titanium, vanadium, chromium, and scandium.

[0005] In one embodiment, a magnetic recording head includes: a first shield; a second shield; and a non-stoichiometric nitrogen-doped MgXO layer disposed between the first shield and the second shield, wherein X is a cation.

[0006] In another embodiment, a spin-orbit torque (SOT) device includes: a spin-orbit torque (SOT) layer; a ferromagnetic layer; and a first nitrogen-doped MgXO layer disposed between the SOT layer and the ferromagnetic layer, wherein X is a cation.

[0007] In another embodiment, a device includes: a non-stoichiometric nitrogen-doped MgXO layer, wherein X is a cation; a first ferromagnetic layer disposed on the non-stoichiometric nitrogen-doped MgXO layer; and a capping layer disposed on the first ferromagnetic layer. Attached Figure Description

[0008] Therefore, by referring to the embodiments, one can obtain a way to understand the above-described features of this disclosure in detail, a more specific description of this disclosure, and the above brief overview, some of which are illustrated in the accompanying drawings. However, it should be noted that the drawings only illustrate typical embodiments of this disclosure and should therefore not be considered as limiting its scope, as this disclosure allows for other equally effective embodiments.

[0009] Figure 1 This is a schematic diagram of some implementation schemes of a magnetic media driver.

[0010] Figure 2 This is a partial cross-sectional side view of some implementations of the read / write head.

[0011] Figures 3A to 3C are a series of curves showing the nitrogen content of nitrogen-doped MgTiO at different deposition times.

[0012] Figure 4A and Figure 4B The effective RA ratio and the variation of nitrogen content with thickness are illustrated between nitrogen-doped MgTiO and undoped MgTiO.

[0013] Figure 5 This is a schematic diagram of a SOT stack according to one implementation scheme.

[0014] Figure 6 This is a schematic diagram of a sensor according to one implementation scheme.

[0015] Figure 7 This is a schematic diagram of a sensor according to another embodiment.

[0016] 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

[0017] 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 over the prior art, whether a particular advantage is achieved by a given embodiment is not a limitation of this disclosure. Therefore, the following aspects, features, embodiments, and advantages are merely illustrative and should not be considered as 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 as elements or limitations of the appended claims unless expressly stated in the claims.

[0018] It has been shown that nitrogen doping into insulating layers can reduce the band gap. Nitrogen-doped magnesium oxide (MgO) is challenging. Cations can be added to allow magnesium to remain on the nitrogen dopant without highly oxidizing or nitriding the cations. The resulting nitrogen-doped MgXO (where X is a cation) exhibits a lower band gap compared to very similar barrier layers that have neither nitrogen nor cations, thus improving thermal and electrical reliability. Nitrogen-doped MgXO is non-stoichiometric, whereas nitrogen oxides are stoichiometric. Example cations that can be used include aluminum, titanium, vanadium, chromium, and scandium.

[0019] Figure 1 This is a schematic diagram of some embodiments of a magnetic media drive 100. Such a magnetic media drive 100 may be a single drive or include multiple drives. For ease of 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 records on each disk 112 are 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.

[0020] At least one slider 113 is positioned near the disk 112, and each slider 113 supports one or more head assemblies 121. As the disk 112 rotates, the slider 113 moves 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. The actuator device 127 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 are controlled by a motor current signal supplied by a control unit 129.

[0021] 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 at small, substantially constant intervals.

[0022] Various components of the disk drive 100 are controlled during operation by control signals (such as access control signals and internal clock signals) generated by the control unit 129. Typically, the control unit 129 includes logic control circuitry, storage devices, 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 via the recording channel 125 to and from the write and read heads on component 121.

[0023] The above description of typical magnetic media drivers and Figure 1The 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.

[0024] Figure 2 This is a partial cross-sectional side view of some embodiments of the read / write head 200. 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. Read / write head 200 includes a media-facing surface (MFS) 212 (such as a gas-bearing surface or air-bearing surface (ABS)) facing the disk 112, a write head 210, and a read head 211. (As...) 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.

[0025] The write head 210 includes a master pole 220, a front shield 206, a rear shield 240, an optional enhancement device 250, and a coil 218 for activating the master pole 220. The coil 218 may have a "pancake" shape, rather than... Figure 2 The illustrated "spiral" structure, a "pancake-shaped" structure, is wound around the back contact between the main electrode 220 and the tail shield 240. When included to achieve, for example, microwave-assisted magnetic recording (MAMR) effects, an enhancement device 250 in the form of a spin-torque oscillator is formed in the gap 254 between the main electrode 220 and the tail shield 240. The enhancement device 250 may also be in the form of a stack of materials comprising one or more conductive, magnetic, and / or non-magnetic materials to provide an auxiliary write effect. In other embodiments, to provide a heat-assisted magnetic recording (HAMR) effect, a near-field transducer (NFT) coupled to an external light source may be disposed near the main electrode to provide localized heating on the magnetic recording medium 112, thereby reducing its coercivity for the auxiliary write effect.

[0026] The main electrode 220 includes a tail cone 242 and a front cone 244. The tail cone 242 extends from a recessed location in the MFS 212. The front cone 244 extends from a recessed location 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. Instead, 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 be magnetic materials, such as a NiFe alloy. In some embodiments, the tail shield 240 may include a tail shield thermal buffer layer 241. The tail shield thermal buffer layer 241 may comprise 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 buffer layer.

[0027] In some embodiments, the magnetic read head 211 is a magnetoresistive (MR) read head, which includes an MR sensing element 204 located between shields S1 and S2. In other embodiments, the magnetic read head 211 is a magnetic tunnel junction (MTJ) read head, which includes an MTJ sensing element 204 located between 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. The MTJ configuration may include two magnetic layers separated by a barrier layer. The barrier layer typically contains MgO and has a significant impact on the overall performance of the MTJ and the entire sensor and read head. In other embodiments, the magnetic read head 211 includes a material stack between the two shields S1 and S2 for providing sensing based on the spin-orbit torque (SOT) effect. MgO may also be used within the layers used for such SOT material stacks.

[0028] Typically, increasing the thickness of the barrier layer has led to a higher resistivity-area (RA) product, which reduces the signal-to-noise ratio (SNR) of the entire MTJ or sensor stack. As will be discussed herein, nitrogen-doped MgXO layers as barrier layers reduce the bandgap compared to conventional MgO barrier layers. Nitrogen-doped MgXO layers achieve much thicker TMR barrier elements with the same resistivity-area (RA) product, thereby improving the thermal and electrical reliability of the barrier layer. In particular, the increased barrier layer thickness by this method provides increased resistance to migration while still maintaining a small RA. A small RA is beneficial to a better signal-to-noise ratio (SNR) for the entire MTJ or sensor stack. Additionally, since nitrogen doping can reduce the grain size, the barrier grain size of the epitaxial stack is maintained or enhanced. It should be noted that although the barrier layer characteristics have been discussed in the context of magnetic recording read heads, MTJs have a variety of other applications beyond read heads in magnetic recording devices, such as in magnetoresistive random access memory (MRAM) and sensor and / or logic applications. Therefore, this disclosure is not limited to read heads.

[0029] Figures 3A through 3C are a series of graphs illustrating the increase in nitrogen content with increasing total deposition time, indicating N doping in MgTiO. In Figure 3A, the Y-axis represents the estimated concentrations of Mg, Ti, N, and O in atomic percentages from the XPS technique, while the X-axis is the XPS sputtering time in minutes for a 40-second deposition process. In Figure 3B, the Y-axis represents the estimated concentrations of Mg, Ti, N, and O in atomic percentages from the GDS technique, while the X-axis is the GDS sputtering time in seconds for a 200-second deposition process. In Figure 3C, the Y-axis represents the estimated GDS concentrations of Mg, Ti, N, and O in atomic percentages, while the X-axis represents the GDS sputtering time in seconds for a 240-second deposition process. In each case from Figures 3A to 3C, the increase in sputtering time indicates that the increase in nitrogen content is roughly correlated with the increase in each of Mg, Ti, and O. Therefore, Figures 3A to 3C show that nitrogen doping is occurring in MgTiO, and the doping amount increases with thickness (deposition time).

[0030] Table I below illustrates the effect of nitrogen on RA, and specifically shows that the RA ratio of nitrogen-doped MgTiO (identified as N-MgTiO in Table I) to that of undoped MgTiO decreases with increasing thickness (see columns 5 and 8 below from the left). RA was measured on a TMR stack in which a barrier is sandwiched between a free CoFe layer and a reference or pinned CoFe layer, which is biased by AFM exchange. The RA product was measured on this TMR stack using in-plane current technique (CIPT). For each RA of undoped MgTiO and nitrogen-doped MgTiO, the corresponding RA of each increases with increasing thickness, but at a much lower rate than that of undoped MgTiO (columns 4 and 7). Furthermore, annealing increases the RA of MgTiO by a much greater amount than that of nitrogen-doped MgTiO. Table I also shows the XPS nitrogen concentration of the films.

[0031] Table I-RA Comparison

[0032]

[0033] Figure 4A The data in Table I are plotted against columns 5 and 8 relative to column 1, showing the decrease in the RA ratio (Y-axis) of nitrogen-doped MgTiO compared to undoped MgTiO with increasing thickness (X-axis). For thicker films, the RA ratio decreases significantly, indicating that the band gap decreases with increasing nitrogen content. The horizontal line at 1.0 indicates the decrease in the band gap with increasing nitrogen content. Figure 4A For the specific nitrogen gas flow example, the minimum thickness is approximately 10 angstroms. Beyond this thickness, the band gap of N2-doped MgTiO is smaller than that of undoped N2. Depending on the deposition conditions (such as the nitrogen gas flow), the thickness threshold with a ratio below 1.0 may change. Higher nitrogen deposition conditions are expected to decrease this threshold thickness, while lower nitrogen deposition should increase it. Figure 4B The XPS nitrogen concentration as a function of thickness is shown. Figure 4B The vertical scale represents the average XPS nitrogen concentration measured in the actual CIPT-RA wafer stack shown in Table I, while the horizontal axis represents the thickness of the nitrogen-doped MgTiO layer in angstroms. Clearly, the XPS nitrogen content (atomic percentage) increases linearly with the thickness of the nitrogen-doped MgTiO layer. The sensitivity (slope) will depend on the deposition conditions. Therefore, Table I, along with Figures 3A to 3C and... Figures 4A to 4BTogether, it is shown that the nitrogen-doped MgXO (N-MgTiO in Table I) layer reduces the band gap. A reduced band gap allows the device to operate at lower voltages and has a thicker blocking thickness. The nitrogen-doped MgXO layer is different from MgXON. In other words, nitrogen-doped magnesium cation oxide is different from magnesium cation oxynitride. Oxides are stoichiometric, while nitrogen-doped oxides are non-stoichiometric. The embodiments disclosed herein are nitrogen-doped oxides, not oxynitrides. In other words, the embodiments disclosed herein are for non-stoichiometric nitrogen-doped MgXO, not stoichiometric oxynitrides (e.g., MgXON).

[0034] Figure 5 This is a schematic diagram of a SOT stack according to some embodiments. The SOT stack can be fabricated using SOT layers (e.g., BiSb layers with (012) orientation) that have a large spin Hall angle effect and high conductivity. Such layers can be used in conjunction with ferromagnetically free layers to form spin-orbit torque (SOT) based magnetic tunnel junction (MTJ) devices. Various embodiments include spin-orbit torque devices, for example, in magnetic recording heads, such as as part of read heads and / or microwave-assisted magnetic recording (MAMR) write heads. In another example, the SOT stack can be used in a magnetoresistive random access memory (MRAM) device. The SOTMTJ device can be a vertical stack configuration or an in-plane stack configuration.

[0035] In one implementation, the SOT stack can be a magnetic recording head (such as...) Figure 2 This is part of the read head 211 or write head 210. In other embodiments, the SOT stack may be part of a magnetoresistive random access memory (MRAM) cell, a magnetic sensor, or an SOT-based logic element that can be used in AI applications. Various end-application embodiments are further described in commonly owned U.S. Patent No. 11,763,973 B2 entitled “Buffer layers and interlayers that promote BiSbX(012) alloy orientation for SOT and MRAM devices,” the disclosure of which is incorporated herein by reference. However, in this disclosure, the SOT layers are not limited to BiSbX(012) alloy and may be fabricated using other material options and orientations.

[0036] Generally, the SOT stack 500 comprises functional layers of SOT layer 516 and ferromagnetic layer 510, separated by various layers including an intermediate layer 514 and a nitrogen-doped MgXO layer 512. Depending on the end application (e.g., top or bottom), the placement of the SOT layer 516 and ferromagnetic layer 510 may be reversed. Additionally, as disclosed in the co-owned '973 patent cited above, additional layers may be added to the entire stack depending on the application.

[0037] Figure 5 An example stack configuration is provided. The SOT stack 500 includes a first non-magnetic conductive layer 502. The SOT stack 500 is used in magnetic recording heads and is positioned between the main poles and the shield (e.g., as shown in the image). Figure 2 In embodiments between reinforcing elements 250, the conductive layer 502 may be disposed on the main electrode. In other embodiments, the conductive layer 502 may be an electrical contact (electrode) or disposed on an electrical contact. Suitable materials for the first nonmagnetic conductive layer 502 include nonmagnetic metal layers with low resistivity (such as Ta, Ru) or nanocrystalline nonmagnetic layers with high resistivity (such as alloys, such as NiFeX, CoFeX, where X = W, Ta, or Hf). A seed layer 504 is disposed on the first nonmagnetic conductive layer 502. Suitable materials for the seed layer 504 include textured layers (such as RuAl) for epitaxial stacking and standard AFM for providing AP coupling to the FM 510 layer. A first nitrogen-doped MgXO layer 506 is disposed on the seed layer 504. The first nitrogen-doped MgXO layer 506 is a nonstoichiometric layer. A second nonmagnetic conductive layer 508 is disposed on the first nitrogen-doped MgXO layer 506. Suitable materials for the second nonmagnetic conductive layer 508 include ruthenium. A ferromagnetic layer 510 is disposed on the second non-magnetic conductive layer 508. Suitable materials for the ferromagnetic layer 510 include NiFe, CoFe, NiFeX, CoFeX, FeX, or NiX, where X = Cr, Co, Ni, Cu, Si, Ge, Al, Ti, V, Mn, Zr, Nb, Mo, Rh, W, Ta, Hf, Re, Ir, Pt, and C, N, B, and combinations thereof.

[0038] A second nitrogen-doped MgXO layer 512 is disposed on the first ferromagnetic layer 510. The second nitrogen-doped MgXO layer 512 is a non-stoichiometric layer. The second nitrogen-doped MgXO layer 512 is substantially the same as the first nitrogen-doped MgXO layer 506. A first intermediate layer 514 is disposed on the second nitrogen-doped MgXO layer 512. Suitable materials for the first intermediate layer 514 include amorphous / nanocrystalline nonmagnetic materials, including NiFe, CoFe, NiFeX, CoFeX, FeX, NiX, or CuX, where X = Cr, Co, Ni, Cu, Si, Al, Mn, Si, Ge, Zr, Nb, Mo, Ta, Hf, W, Ir, N, and B, and combinations thereof.

[0039] SOT layer 516 is disposed on intermediate layer 514. Suitable materials for SOT layer 516 include undoped BiSb or doped BiSbX, wherein the dopant is less than about 10%, and wherein X is extracted from elements that do not readily interact with Bi or Sb, such as Cu, Ag, Si, Ge, Mn, Ni, Co, Mo, Sn, C, B, N, In, Te, Se, Y, Zr, Nb, Mo, Ta, W, Pt, Ir, Ti, or alloys of one or more of the foregoing elements, such as CuAg, CuNi, CoCu, AgSn. Other suitable SOT materials may include YBiPt and [other SOT material options, such as topological insulators or heavy metal materials with suitable spin-orbit torque characteristics, such as BiSe, WTe, CdTe, Pt, Ta, W, β-tungsten, β-tantalum, YBiPtX, wherein X is as listed above, and combinations thereof].

[0040] A second intermediate layer 518 is disposed on the SOT layer 516 and contains a material similar to that of intermediate layer 514. A third nitrogen-doped MgXO layer 520 is disposed on the second intermediate layer 518. The third nitrogen-doped MgXO layer 520 is a non-stoichiometric layer. The third nitrogen-doped MgXO layer 520 is substantially the same as the first nitrogen-doped MgXO layer 506 and the second nitrogen-doped MgXO layer 512. A conductive capping layer 522 is disposed on the third nitrogen-doped MgXO layer 520. The capping layer 522 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 NiFeGe, NiFeTa, NiTa, NiHf, NiFeHf, CoHf, CoFeHf, NiWTa, NiFeW, NiW, WRe, β-Ta and β-W; or nitrides, oxides or borides of the above elements, 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.

[0041] In various embodiments, the first nitrogen-doped MgXO layer 506 and the third nitrogen-doped MgXO layer 520 can be optional. Due to the aforementioned bandgap reduction properties of the MgXO layers, the second nitrogen-doped MgXO layer 512 between the SOT layer 516 and the ferromagnetic layer 510 reduces shunting, which enhances the overall functional effectiveness in the interaction between the two layers. The first nitrogen-doped MgXO layer 506 can also be used to reduce shunting, and the third nitrogen-doped MgXO layer 512 can serve as a capping layer. It is important to note that when there is more than one nitrogen-doped MgXO layer in the structure, the nitrogen-doped MgXO layers are substantially identical. Although there may be slight differences due to trace impurities (i.e., less than 0.5 atomic percent in total), the composition of the nitrogen-doped MgXO layers is the same. The term "substantially" is intended to allow impurities that do not alter the function of the nitrogen-doped MgXO layer. Impurities greater than 0.5 atomic percent will be considered outside the range of "substantially identical". The nitrogen-doped MgXO layer serves as a diffusion barrier layer.

[0042] Figure 6This is a schematic diagram of a sensor 600 according to one embodiment. Sensor 600 is a TMR sensor. Sensor 600 includes a first non-magnetic conductive layer 602 disposed on S1. Suitable materials for the first non-magnetic conductive layer 602 include Ta, Ru, NiFeTa, NiCr, CoHf, NiAl, and RuAl. A seed layer 604 is disposed on the first non-magnetic conductive layer 602. Suitable materials for the seed layer 604 include NiAl and RuAl. An antiferromagnetic (AFM) layer 606 is disposed on the seed layer 604. Suitable materials for the AFM layer 606 include IrMn. A ferromagnetic layer 607 is disposed on the AFM layer 606. Suitable materials for the ferromagnetic layer 607 include NiFe, CoFe, NiFeX, CoFeX, FeX, or NiX, where X = Cr, Co, Ni, Cu, Si, Ge, Al, Ti, V, Mn, Zr, Nb, Mo, Rh, W, Ta, Hf, Re, Ir, Pt, and C, N, B, and combinations thereof.

[0043] A nitrogen-doped MgXO layer 608 is disposed on the ferromagnetic layer 607. The nitrogen-doped MgXO layer 608 is a non-stoichiometric layer. A ferromagnetic layer 610 is disposed on the nitrogen-doped MgXO layer 608. Suitable materials for the ferromagnetic layer 610 include NiFe, CoFe, NiFeX, CoFeX, FeX, or NiX, where X = Cr, Co, Ni, Cu, Si, Ge, Al, Ti, V, Mn, Zr, Nb, Mo, Rh, W, Ta, Hf, Re, Ir, Pt, and C, N, B, and combinations thereof. In some embodiments, the ferromagnetic layer 610 is a free layer whose magnetization direction responds to an external field to be sensed, and the ferromagnetic layer 607 is a pinned layer whose magnetization direction is fixed. A capping layer 612 is disposed on the ferromagnetic layer 610. The capping layer 612 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 NiFeGe, NiFeTa, NiTa, NiHf, NiFeHf, CoHf, CoFeHf, NiWTa, NiFeW, NiW, WRe, β-Ta, and β-W; or nitrides, oxides, or borides of the aforementioned elements, 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. S2 will be disposed on the capping layer 612.

[0044] Figure 7This is a schematic diagram of a sensor 700 according to another embodiment. Sensor 700 is a dual free-layer (DFL) sensor. Sensor 700 includes a first non-magnetic conductive layer 702 disposed on S1. Suitable materials for the first non-magnetic conductive layer 702 include Ta, Ru, NiFeTa, NiFeGe, NiGe, NiCr, CoHf, NiAl, and RuAl. A seed layer 704 is disposed on the first non-magnetic conductive layer 702. Suitable materials for the seed layer 704 include NiAl and RuAl. A first ferromagnetic layer 706 is disposed on the seed layer 704. Suitable materials for the first ferromagnetic layer 706 include NiFe, CoFe, NiFeX, CoFeX, FeX, or NiX, where X = Cr, Co, Ni, Cu, Si, Ge, Al, Ti, V, Mn, Zr, Nb, Mo, Rh, W, Ta, Hf, Re, Ir, Pt, and C, N, B, and combinations thereof.

[0045] A nitrogen-doped MgXO layer 708 is disposed on the first ferromagnetic layer 706. The nitrogen-doped MgXO layer 708 is a non-stoichiometric layer. A second ferromagnetic layer 710 is disposed on the nitrogen-doped MgXO layer 708. Suitable materials for the second ferromagnetic layer 710 include NiFe, CoFe, NiFeX, CoFeX, FeX, or NiX, where X = Cr, Co, Ni, Cu, Si, Ge, Al, Ti, V, Mn, Zr, Nb, Mo, Rh, W, Ta, Hf, Re, Ir, Pt, and C, N, B, and combinations thereof. In some embodiments, both the first ferromagnetic layer 706 and the second ferromagnetic layer 710 are free layers, and they form a double free layer in the DFL sensor. A capping layer 712 is disposed on the second ferromagnetic layer 710. The capping layer 712 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 NiFeGe, NiFeTa, NiTa, NiHf, NiFeHf, CoHf, CoFeHf, NiWTa, NiFeW, NiW, WRe, β-Ta, and β-W; or nitrides, oxides, or borides of the aforementioned elements, 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. S2 will be disposed on the capping layer 712.

[0046] It should be noted that Figures 6 to 7The TMR and DFL sensor stacks described are not limited to sensor applications or magnetic recording applications. In other embodiments, such a stack or a portion thereof may be part of an MRAM memory cell including a magnetic tunnel junction (MTJ) or a stand-alone sensor external to a magnetic recording device. More generally, the disclosed nitrogen-doped MgXO layer can be used as a barrier layer for any application of the MTJ. For example, the nitrogen-doped MgXO layer can be used as a barrier layer separating two ferromagnetic layers, which can be used as pinned layers or free layers, such as in a configuration used in an MRAM cell. Furthermore, Figure 6 and Figure 7 The shielding components S1 and S2 disclosed herein are optional, for example, when the sensor is used in a stand-alone sensor application and is not inside the magnetic recording head.

[0047] By using non-stoichiometric nitrogen-doped MgXO layers in various device stacks for magnetic recording, memory, logic and other applications, the band gap can be reduced with a small RA while maintaining a thicker barrier thickness / good reliability.

[0048] In one embodiment, a magnetic recording head includes: a first shield; a second shield; and a non-stoichiometric nitrogen-doped MgXO layer disposed between the first and second shields, wherein X is a cation. Nitrogen is present in an amount of less than 10 atomic percent. Nitrogen is present in an amount of less than 5 atomic percent. X is selected from the group consisting of Al, Sc, Ti, V, Cr, Zn, Zr, Nb, Mo, Ta, Hf, W, and combinations thereof. The nitrogen-doped MgXO layer is disposed within a spin-orbit torque structure. The first shield is a front-end shield, the second shield is a tail-end shield, the head also includes a master pole, and the spin-orbit torque structure is disposed between the master pole and the tail-end shield. The nitrogen-doped MgXO layer is a first nitrogen-doped MgXO layer, the head also includes a second nitrogen-doped MgXO layer, and the first and second nitrogen-doped MgXO layers are substantially identical. The magnetic head further includes: a first free layer; and a second free layer, wherein a nitrogen-doped MgXO layer is disposed between the first free layer and the second free layer. The magnetic head also includes: an antiferromagnetic (AFM) layer; an FM layer and a free layer, wherein a nitrogen-doped MgXO layer is disposed between the AFM layer and the free layer. A magnetic storage device including a magnetic head is also envisioned.

[0049] In another embodiment, a spin-orbit torque (SOT) device includes: a spin-orbit torque (SOT) layer; a ferromagnetic layer; and a first nitrogen-doped MgXO layer disposed between the SOT layer and the ferromagnetic layer, wherein X is a cation. The SOT device also includes an intermediate layer between the SOT layer and the ferromagnetic layer. X is selected from the group consisting of Al, Sc, Ti, V, Cr, Zn, Zr, Nb, Mo, Ta, Hf, W, and combinations thereof. The SOT device also includes a second nitrogen-doped MgXO layer disposed between the ferromagnetic layer and an electrode or shield, or between the SOT layer and an electrode or shield. A magnetic storage device including an SOT device is also envisioned. A magnetoresistive random access memory (MRAM) device including an SOT device is also envisioned.

[0050] In another embodiment, a device includes: a non-stoichiometric nitrogen-doped MgXO layer, wherein X is a cation; a first ferromagnetic layer disposed on the non-stoichiometric nitrogen-doped MgXO layer; and a capping layer disposed on a second ferromagnetic layer. The device further includes an antiferromagnetic (AFM) layer and the first ferromagnetic layer, wherein the non-stoichiometric nitrogen-doped MgXO layer is disposed between the first and second ferromagnetic layers. The device also includes a second ferromagnetic layer, wherein the non-stoichiometric nitrogen-doped MgXO layer is disposed between the second and first ferromagnetic layers. A magnetic head for a magnetic storage device is also envisioned, the magnetic storage device including the device. A magnetic storage device including a magnetic head is also envisioned. A magnetoresistive random access memory (MRAM) device is also envisioned, the magnetoresistive random access memory (MRAM) device including the device.

[0051] While the foregoing describes embodiments of this disclosure, other and additional embodiments of this disclosure may be contemplated without departing from the basic scope of this disclosure, the scope of which is defined by the appended claims.

Claims

1. A magnetic recording head, the magnetic recording head comprising: First shielding component; Second shielding component; and A non-stoichiometric nitrogen-doped MgXO layer is disposed between the first shield and the second shield, wherein X is a cation.

2. The magnetic head according to claim 1, wherein the nitrogen is present in an amount of less than 10 atomic percentages.

3. The magnetic head according to claim 2, wherein the nitrogen is present in an amount of less than 5 atomic percentages.

4. The magnetic head according to claim 1, wherein X is selected from the group consisting of Al, Sc, Ti, V, Cr, Zn, Zr, Nb, Mo, Ta, Hf, W and combinations thereof.

5. The magnetic head according to claim 1, wherein the nitrogen-doped MgXO layer is disposed within a spin-orbit torque structure, the spin-orbit torque structure comprising: Spin-orbit torque (SOT) layer; Ferromagnetic layer; and The nitrogen-doped MgXO layer is disposed between the SOT layer and the ferromagnetic layer.

6. The magnetic head according to claim 5, wherein the first shield is a front shield, wherein the second shield is a tail shield, wherein the magnetic head further includes a main pole, and wherein the spin-orbit torque structure is disposed between the main pole and the tail shield or the front shield.

7. The magnetic head according to claim 5, wherein the nitrogen-doped MgXO layer is a first nitrogen-doped MgXO layer, wherein the magnetic head further comprises a second nitrogen-doped MgXO layer, and wherein the first nitrogen-doped MgXO layer and the second nitrogen-doped MgXO layer are substantially the same.

8. The magnetic head according to claim 1, further comprising: First ferromagnetic free layer; and The second ferromagnetic free layer, wherein the nitrogen-doped MgXO layer is disposed between the first ferromagnetic free layer and the second ferromagnetic free layer.

9. The magnetic head according to claim 1, further comprising: Antiferromagnetic (AFM) layer; Ferromagnetic layer; and A ferromagnetic free layer, wherein the nitrogen-doped MgXO layer is disposed between the ferromagnetic layer and the ferromagnetic free layer.

10. A magnetic storage device, the magnetic storage device comprising the magnetic head according to claim 1.

11. A spin-orbit torque (SOT) device, the spin-orbit torque (SOT) device comprising: Spin-orbit torque (SOT) layer; Ferromagnetic layer; and A first nitrogen-doped MgXO layer is disposed between the SOT layer and the ferromagnetic layer, wherein X is a cation.

12. The SOT device according to claim 11, wherein the SOT device further comprises an intermediate layer between the SOT layer and the ferromagnetic layer.

13. The SOT device of claim 11, wherein X is selected from the group consisting of Al, Sc, Ti, V, Cr, Zn, Zr, Nb, Hf, W and combinations thereof.

14. The SOT device according to claim 11, wherein the SOT device further comprises a second nitrogen-doped MgXO layer, the second nitrogen-doped MgXO layer being disposed between the ferromagnetic layer and the electrode or shielding member, or disposed between the SOT layer and the electrode or shielding member.

15. A magnetic storage device comprising the SOT device according to claim 11.

16. A magnetoresistive random access memory (MRAM) device, the magnetoresistive random access memory (MRAM) device comprising the SOT device according to claim 11.

17. A device, the device comprising: Non-stoichiometric nitrogen-doped MgXO layer, where X is a cation; and First ferromagnetic layer; and The second ferromagnetic layer, wherein the non-stoichiometric nitrogen-doped MgXO layer is disposed between the first ferromagnetic layer and the second ferromagnetic layer.

18. The device of claim 17, further comprising an antiferromagnetic (AFM) layer.

19. A magnetic head for a magnetic storage device, the magnetic head comprising the device according to claim 17.

20. A magnetic storage device, the magnetic storage device comprising the magnetic head according to claim 19.

21. A magnetoresistive random access memory (MRAM) device, the magnetoresistive random access memory (MRAM) device comprising the device according to claim 17.

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