Magnetic recording medium having a tungsten pre-seed layer

Abstract

Various apparatuses, systems, methods, and media are disclosed to provide a magnetic recording medium having a tungsten (W) pre-seed layer. The W pre-seed layer has higher electrical conductivity than a CrTi pre-seed layer having a similar thickness. In one embodiment, the W pre-seed layer is made of about 95 atomic percent or greater than 95 atomic percent W. The W pre-seed layer has a lower resistivity than the CrTi pre-seed layer. Thus, if similar electrical conductivity is achieved, the thickness of the W pre-seed layer can be reduced compared to the thickness of the CrTi pre-seed layer. Magnetic recording materials deposited on top of the W pre-seed layer having the reduced thickness provide comparable crystalline orientation and recording performance to those magnetic recording materials deposited on top of a thicker CrTi pre-seed layer having similar electrical conductivity.

Description

TECHNICAL FIELD

[0001] The present disclosure relates in some aspects to magnetic recording media for use with magnetic recording devices, and more specifically to magnetic recording media having a pre-seed layer made of tungsten (W). BACKGROUND

[0002] Magnetic storage systems, such as hard disk drives (HDDs), are used in a wide variety of devices in both stationary and mobile computing environments. Examples of devices incorporating magnetic storage systems include desktop computers, portable notebook computers, portable hard drives, digital versatile disc (DVD) players, high-definition television (HDTV) receivers, vehicle control systems, cellular or mobile phones, television set-top boxes, digital cameras, digital video cameras, video game consoles, and portable media players.

[0003] A typical disk drive includes a magnetic storage medium in the form of one or more flat disks or platters. The disks are typically formed of two primary substances, a substrate material that gives it structure and rigidity, and a magnetic media coating that holds the magnetic pulses or torques representing data in the recording layer within the coating. A typical disk drive also includes read and write heads, usually in the form of magnetic transducers that can sense and / or change the magnetic field stored on the recording layer of the disk. When the magnetic storage medium uses a non-conductive substrate, a pre-seed layer can be deposited on the non-conductive substrate so that a bias voltage can be applied during deposition of some or all of the subsequent media films to form the magnetic storage medium. The pre-seed layer should have sufficient electrical conductivity to facilitate the deposition process. SUMMARY

[0004] The following presents a simplified summary of some aspects of the disclosure to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated features of the disclosure, and is not intended to identify key or critical elements of the disclosure or to delineate the scope of any or all aspects thereof. Its sole purpose is to present various concepts of some aspects of the disclosure in a simplified form as a prelude to the more detailed description that is presented later.

[0005] In one embodiment, the magnetic recording medium includes a rigid substrate, a pre-seed layer on the rigid substrate, an amorphous soft underlayer (SUL) on the pre-seed layer, a seed layer on the amorphous SUL, and a magnetic recording layer (MRL) on the seed layer. The pre-seed layer includes W. In one aspect, the resistivity of the pre-seed layer is 12 x 10 -8 ohm-m (Ω·m) or less. In one aspect, the thickness of the pre-seed layer is less than 30 nm, such as 14 nm or less.

[0006] In another embodiment, a data storage device includes a slider including the magnetic head and the magnetic recording medium described above. The slider is configured to write information to the magnetic recording layer of the magnetic recording medium.

[0007] In another embodiment, a method for manufacturing a magnetic recording medium is provided. The method provides a rigid substrate and a pre-seed layer on the rigid substrate. The pre-seed layer includes W. The method further provides an amorphous soft underlayer (SUL) on the pre-seed layer. The method further provides a seed layer on the amorphous SUL. The method further provides a magnetic recording layer (MRL) on the seed layer. The method further includes at least one of polishing the pre-seed layer or oxidizing the pre-seed layer.

[0008] These and other aspects of the present disclosure will become more fully understood upon consideration of the following detailed description, in conjunction with the accompanying drawings. Other aspects, features, and embodiments of the present disclosure will become apparent to those of ordinary skill in the art, upon reviewing the following description of specific embodiments of the present disclosure in conjunction with the accompanying drawings. While features of the present disclosure can be discussed relative to a particular embodiment and a figure below, all embodiments of the present disclosure can include one or more of the advantageous features discussed herein. In other words, while one or more embodiments can be discussed as having certain advantageous features, one or more of such features can also be used in accordance with the various embodiments of the present disclosure discussed herein. In similar fashion, while embodiments can be discussed as device, system or method embodiments it is to be understood that such embodiments can be implemented in various devices, systems, and methods. BRIEF DESCRIPTION OF DRAWINGS

[0009] A more particular description will be rendered by reference to specific aspects illustrated in the appended drawings, of which specific aspects are shown. It is appreciated that these drawings are only illustrative and are therefore not to be considered limiting in their scope. The present disclosure will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:

[0010] Figure 1 A top view of a magnetic disk drive configured for magnetic recording in accordance with one aspect of the present disclosure includes a slider and a magnetic recording medium having a tungsten pre-seed layer.

[0011] Figure 2 A top view of a magnetic disk drive configured for magnetic recording in accordance with one aspect of the present disclosure includes a slider and a magnetic recording medium having a tungsten pre-seed layer. Figure 1 A side view of a slider and a magnetic recording medium of

[0012] Figure 3 A side view of a magnetic recording medium having a tungsten (W) pre-seed layer in accordance with one aspect of the present disclosure.

[0013] Figure 4 A flow chart showing a first process for manufacturing a magnetic recording medium having a pre-seed layer made of W in accordance with some aspects of the present disclosure.

[0014] Figure 5 To illustrate the process described above with respect to Figure 3 a flowchart of a process for manufacturing an additional layer on a pre-seed layer of a magnetic recording medium.

[0015] Figure 6 To illustrate a flowchart of a process for manufacturing a magnetic recording medium having a W pre-seed layer according to some aspects of the present disclosure.

[0016] Figure 7 To illustrate a flowchart of a process for manufacturing a magnetic recording medium having a polished pre-seed layer made of W according to some aspects of the present disclosure.

[0017] Figure 8 To illustrate a flowchart of a process for manufacturing a magnetic recording medium having an oxidized pre-seed layer made of W according to some aspects of the present disclosure.

[0018] Figure 9 To illustrate a flowchart of a process for manufacturing a magnetic recording medium having a polished and oxidized pre-seed layer made of W according to some aspects of the present disclosure.

[0019] Figure 10 To illustrate a flowchart of a process for manufacturing a magnetic recording medium having an oxidized and polished pre-seed layer made of W according to some aspects of the present disclosure.

[0020] Figure 11 To illustrate a general system for manufacturing a magnetic recording medium having a pre-seed layer made of W according to some aspects of the present disclosure. DETAILED DESCRIPTION

[0021] In the following detailed description, reference is made to the accompanying drawings, which form a part hereof. In addition to the illustrative aspects, aspects, and features described above, additional aspects, aspects, and features will become apparent in view of the drawings and following detailed description. Descriptions of elements in each of the figures can be made in reference to elements of the other figures. The same numbers can be used in different drawings to designate the same or similar elements.

[0022] The present disclosure relates, in some aspects, to various apparatuses, systems, methods, and media for magnetic storage devices. Some magnetic recording media use a non-conductive substrate, such as glass and ceramic. In such cases, a pre-seed layer can be deposited on the non-conductive substrate so that a bias voltage can be applied to the substrate during deposition of subsequent media films on the substrate. In some examples, the pre-seed layer can be made of a metal alloy including Cr and Ti with or without additional elements. Generally, a CrTi pre-seed layer can need to be relatively thick (e.g., 30 to 60 nm) in order to provide sufficient electrical conductivity for applying a bias voltage during deposition of subsequent media films on the substrate. However, forming a thick pre-seed layer can involve multiple deposition stations (which can be limited by the deposition machine), which can increase manufacturing costs. Moreover, forming a thick pre-seed layer can result in high particle generation and rapid depletion of target material during the deposition process.

[0023] Some aspects of the present disclosure design a magnetic recording medium with a pre-seed layer made of tungsten (W). The W pre-seed layer has higher electrical conductivity than a CrTi pre-seed layer with a similar thickness. In one embodiment, the W pre-seed layer is made of about 95 atomic percent or greater than 95 atomic percent of W. The W pre-seed layer has lower resistivity than the CrTi pre-seed layer. Thus, if similar electrical conductivity is achieved, the thickness of the W pre-seed layer can be reduced compared to the thickness of the CrTi pre-seed layer.

[0024] Figure 1This is a top view of a data storage device 100 (e.g., a disk drive or magnetic recording device) configured for magnetic recording according to one or more aspects of this disclosure. The data storage device 100 includes a slider 108 and a magnetic recording medium 102. The data storage device 100 may include one or more disks / media 102 for storing data. The disks / media 102 reside on a spindle assembly 104 mounted to a drive housing 106. Data may be stored along traces in the magnetic recording layer of the disk 102. Reading and writing of data are performed by a magnetic head 108 (slider) that may have both a write element (e.g., writer 108a) and a read element (e.g., reader 108b). The write element 108a is used to change the properties of the magnetic recording layer of the disk 102 and thereby write information onto the disk 102. In one aspect, the magnetic head 108 may have magnetoresistive (MR) based elements, such as tunneling magnetoresistive (TMR) elements for reading, and write poles having coils energized for writing. In operation, a spindle motor (not shown) rotates the spindle assembly 104, thereby rotating the disk 102 to position the read / write head 108 at a specific location along the desired disk trace 107. The position of the read / write head 108 relative to the disk 102 can be controlled by a control circuitry system 110 (e.g., a microcontroller). Some embodiments of the data storage device 100 are heat-assisted magnetic recording (HAMR), energy-assisted magnetic recording (EAMR), or non-EAMR magnetic data recording systems, including perpendicular magnetic recording (PMR) and shingled magnetic recording (SMR) disk drives or magnetic tape drives.

[0025] Figure 2 for Figure 1 A side view of the slider 108 and the magnetic recording medium 102. The magnetic recording medium 102 may have a pre-seed layer (e.g., made of W (e.g., 95 atomic percent or greater than 95 atomic percent) according to one or more aspects of this disclosure). Figure 3 The pre-seed layer 304 shown. The slider 108 includes a writing element (e.g., a writer) 108a and a reading element (e.g., a reader) 108b positioned along the air bearing surface (ABS) 108c of the slider for writing information to the medium 102 and reading information from the medium 102, respectively.

[0026] Figure 3A side view schematic of a magnetic recording medium 300 having a W pre-seed layer according to one aspect of the disclosure. In some embodiments, the magnetic recording medium 300 can be a PMR, SMR, MAMR, or HAMR medium. The magnetic recording medium 300 has a stack structure with a substrate 302 at a bottom / base layer, a pre-seed layer 304 on the substrate 302, an amorphous soft magnetic underlayer (SUL) 306 on the pre-seed layer 304, a seed layer 308 on the SUL 306, an interlayer 310 on the seed layer 308, an underlayer 312 on the interlayer 310, a magnetic recording layer (MRL) 314 on the underlayer 312, an overcoat layer 316 on the MRL 314. In some embodiments, the medium 300 can have a lubricant layer 318 on the overcoat layer 316.

[0027] In some aspects, the substrate 302 can be made of one or more materials, such as Al alloy, NiP plated Al, glass, glass-ceramic, and / or combinations thereof. In one embodiment, the substrate 302 can be a rigid substrate (e.g., glass or ceramic). In some aspects, the pre-seed layer 304 can be made of a material with suitably low resistivity for applying a bias voltage when using a non-conductive substrate (e.g., glass or ceramic).

[0028] In one aspect, the pre-seed layer 304 can be made of W, such as about 95 atomic percent or greater than 95 atomic percent W. Tungsten is a relatively hard material that makes it suitable as a pre-seed layer that can enhance the scratch resistance of a magnetic recording medium built on top of it. In addition, W has a low resistivity. Thus, a thin pre-seed layer made of W can still provide sufficient electrical conductivity for bias voltage application during deposition of subsequent medium films. In one example, the resistivity of the W pre-seed layer 304 can be about 12 x 10 -8 ohm-m (Ω·m) or less. In one example, the thickness of the W pre-seed layer 304 can be less than about 30 nm, specifically less than about 14 nm, while still providing sufficient electrical conductivity for bias voltage application during fabrication of the magnetic recording medium 300. Generally, the electrical conductivity of the W pre-seed layer 304 is higher than that of a pre-seed layer made of a metal alloy (e.g., CrTi) with a similar thickness. In one example, a W pre-seed layer 304 with a thickness of about 13.7 nm can provide sufficient electrical conductivity to apply a bias voltage for subsequent medium films in a similar manner as a CrTi pre-seed layer with a thickness of about 57.9 nm. In this case, the thickness of the W pre-seed layer 304 can be reduced by about 75% compared to the CrTi pre-seed layer, while the magnetic recording medium deposited on top of the W pre-seed layer and the CrTi pre-seed layer has comparable crystalline orientation and recording performance.

[0029] In some aspects, the amorphous SUL 306 can be made of a material with high permeability, high saturation magnetization, and low coercivity, such as CoFe and one or more elements selected from the group consisting of Mo, Nb, Ta, W, B, Zr, and combinations thereof. In some aspects, the seed layer 308 can be made of any suitable material known in the art. The seed layer 308 has a certain lattice structure and crystalline orientation that can determine the crystalline orientation of layers grown / deposited on the seed layer 308, such as the interlayer 310. In one embodiment, the seed layer 308 can be made of a Ni alloy. In one embodiment, the seed layer 308 can be made of Ru and Al with or without additional elements and / or oxides. In some aspects, the MRL 314 can be made of a CoPt alloy with or without additional other elements or oxides. In some aspects, the MRL 314 can be made of FePt or an alloy selected from FePtX, where X is a material selected from Cu, Ni, and combinations thereof. In some examples, the crystalline orientation of the MRL 314 can facilitate PMR, SMR, MAMR, or HAMR. In some aspects, the overcoat layer 316 can be made of carbon. In some aspects, the lubricant layer 318 can be made of a polymer-based lubricant. In some aspects, the MRL 314 can include one or more recording layers that can be interleaved with an exchange control layer. The recording layers can have the same thickness or different thicknesses.

[0030] As used herein, the terms "over," "under," "upper" and "between" refer to the relative positioning of one layer with respect to other layers. Thus, a layer deposited or disposed over or under another layer can be in direct contact with the other layer or can have one or more intervening layers. Further, a layer deposited or disposed between layers can be in direct contact with the layers or can have one or more intervening layers.

[0031] Figure 4 A flowchart of a process 400 for fabricating a magnetic recording medium having a W pre-seed layer according to some aspects of the present disclosure. In one aspect, the process 400 can be used or modified to fabricate the medium described above with respect to Figure 3 In some aspects, the fabricated medium can be used in a data storage device 100 for Figure 1 In some aspects, the fabricated medium can be used in a data storage device 100 for

[0032] In block 402, the process provides a rigid substrate (e.g., the rigid substrate 302). In some aspects, the substrate can be made of one or more materials, such as an Al alloy, a NiP plated Al, a glass, a glass-ceramic, and / or combinations thereof. In block 404, the process provides a W pre-seed layer (e.g., the pre-seed layer 304) on the substrate. In one embodiment, the W pre-seed layer can be made of about 95 atomic percent or greater than 95 atomic percent of W. In one embodiment, the W pre-seed layer has a thickness of about 12 x 10 -8The resistivity is Ω·m (at 20°C) or lower. In one example, the thickness of the W pre-seed layer may be less than about 14 nm. In block 406, the process provides an additional layer of magnetic recording medium (e.g., one or more of the following layers: SUL, seed layer, interlayer, underlayer, MRL, outer coating, and lubricant layer) on the pre-seed layer.

[0033] Figure 5 To illustrate the above regarding Figure 3 The flowchart describes a process 500 for fabricating an additional layer for a magnetic recording medium. In block 502, the process may provide a SUL (e.g., amorphous SUL 306) on a pre-seed layer. In block 504, the process may provide a seed layer (e.g., seed layer 308) on the SUL. In block 506, the process may provide an interlayer (e.g., interlayer 310) on the seed layer. In block 508, the process may provide a bottom layer (e.g., bottom layer 312) on the interlayer. In block 510, the process may provide a magnetic recording layer (e.g., MRL 314) on the bottom layer. In one embodiment, the magnetic recording layer may comprise one or more magnetic recording layers for magnetically storing data, such as PMR, SMR, MAMR, and HAMR. In block 512, the process may provide an outer coating (e.g., outer coating 316) on the MRL.

[0034] Figure 6 This is a flowchart illustrating a method 600 for manufacturing a magnetic recording medium having a W pre-seed layer according to an embodiment. In one aspect, method 600 can be performed using the system 1100 described below to manufacture the above-described method. Figure 3 The magnetic storage medium described. In some aspects, the manufacturing of the medium can be used for... Figure 1 In the data storage device 100.

[0035] In block 602, the method provides a rigid substrate. For example, the rigid substrate could be... Figure 3 The magnetic recording medium 300 has a substrate 302. In block 604, the method provides a pre-seed layer on a rigid substrate. The pre-seed layer may be made of W, for example, having 95 atomic percent or greater than 95 atomic percent W. In one example, the W pre-seed layer may be... Figure 3 The pre-seed layer 304 of the magnetic recording medium 300. The method involves placing the substrate in a deposition apparatus 1102 (see...). Figure 11 A pre-seed layer is deposited on the substrate. In one embodiment, the resistivity of the pre-seed layer is 12 x 10⁻⁶. -8Ω-m or less. In one embodiment, the pre-seed layer has a thickness of less than 30 nm (e.g., less than about 14 nm). In one embodiment, the pre-seed layer having the first thickness is configured to have a higher electrical conductivity than a CrTi pre-seed layer having the first thickness. The electrical conductivity of the pre-seed layer is determined based on the material composition (e.g., W or CrTi) and thickness of the pre-seed layer. In one embodiment, the pre-seed layer includes at least 95 atomic percent W.

[0036] In block 606, the method provides an amorphous SUL on the pre-seed layer. In one example, the amorphous SUL can be Figure 3 the SUL 306 of the magnetic recording medium 300. In some examples, the amorphous SUL does not include Cr (chromium). The method can use the deposition apparatus 1102 to deposit the amorphous SUL on the pre-seed layer.

[0037] In block 608, the method provides a seed layer on the amorphous SUL. In one example, the seed layer can be Figure 3 the seed layer 308 of the magnetic recording medium 300. The method can use the deposition apparatus 1102 to deposit the seed layer on the amorphous SUL.

[0038] In block 610, the method provides a magnetic recording layer on the seed layer. The method can use the deposition apparatus 1102 to deposit the magnetic recording layer on the pre-seed layer. In one example, the magnetic recording layer can be Figure 3 the MRL 314 of the magnetic recording medium 300. In some embodiments, the method 600 can provide one or more layers (e.g., seed layer, interlayer, underlayer) between the magnetic recording layer and the pre-seed layer. In one embodiment, the amorphous SUL includes CoFe and one or more elements selected from the group consisting of: Mo, Nb, Ta, W, B, Zr, and combinations thereof.

[0039] Figure 7 is a flowchart illustrating a process 700 for manufacturing a magnetic recording medium having a polished W pre-seed layer, in accordance with some aspects of the present disclosure. In one aspect, the process 700 can be used or modified to manufacture the medium described above with respect to Figure 3 In some aspects, the manufactured magnetic recording medium can be used in the data storage device 100 of Figure 1

[0040] ​In block 702, the process provides a rigid substrate (e.g., rigid substrate 302). In some aspects, the substrate can be made of one or more materials, such as Al alloy, NiP plated Al, glass, glass-ceramic, and / or combinations thereof. In block 704, the process provides a W pre-seed layer (e.g., pre-seed layer 304) on the substrate. In one embodiment, the W pre-seed layer can be made of about 95 atomic percent or greater than 95 atomic percent W. In one embodiment, the W pre-seed layer has a thickness of about 12 x 10 -8 Ω·m (at 20°C) or less. In one example, the W pre-seed layer can have a thickness of less than about 14 nm.

[0041] In block 706, the process polishes the W pre-seed layer. In one aspect, the pre-seed layer can be plasma polished, for example. Polishing can reduce the roughness of the surface of the pre-seed layer. The reduction in roughness of the pre-seed layer can result in improved crystalline texture of subsequently deposited media films (e.g., seed layer, interlayer, underlayer, and magnetic recording layer) on the pre-seed layer, and thus increase the recording performance of the media. In particular, the media SNR, linear recording density, and areal recording density or areal density capacity (ADC) can be improved. Polishing can also be used to reduce the head-media spacing (HMS) and enhance the corrosion resistance of the magnetic recording media.

[0042] In block 708, the process provides additional layers of the magnetic recording media (e.g., one or more of SUL, seed layer, interlayer, underlayer, MRL, overcoat layer, and lubricant layer) on the W pre-seed layer. In one embodiment, the process can use process 500 described above to deposit the additional layers on the pre-seed layer.

[0043] Figure 8 A flowchart of a process 800 for fabricating a magnetic recording media having an oxidation pre-seed layer made of W, in accordance with some aspects of the present disclosure, is shown. In one aspect, process 800 can be used or modified to fabricate the magnetic storage media described above with respect to Figure 3 In some aspects, the fabricated media can be used in data storage device 100 of Figure 1

[0044] In block 802, the process provides a rigid substrate (e.g., rigid substrate 302). In some aspects, the substrate can be made of one or more materials, such as Al alloy, NiP plated Al, glass, glass-ceramic, and / or combinations thereof. In block 804, the process provides a W pre-seed layer (e.g., pre-seed layer 304) on the substrate. In one embodiment, the W pre-seed layer can be made of about 95 atomic percent or greater than 95 atomic percent W. In one embodiment, the W pre-seed layer has a thickness of about 12 x 10 -8 Ω·m (at 20°C) or less. In one example, the W pre-seed layer can have a thickness of less than about 14 nm.​

[0045] In block 806, the process oxidizes the W pre-seed layer. Thus, following oxidation, at least the top surface of the pre-seed layer has at least some oxidized form of its constituent metal compound. For example, oxidation of the pre-seed layer can be used to improve recording performance. In some aspects, oxidation of the pre-seed layer is provided in an amount sufficient to reduce intermixing between the pre-seed layer and the SUL to improve recording performance. In one example, the SUL moment of magnetization (Ms) can become higher and the media orientation can improve. The increase in Ms of the SUL contributes to an increase in OW2 of the media, where OW2 (which can sometimes be referred to as "write capability overwrite" or "reverse overwrite") is a measure of perpendicular overwrite (e.g., a measure of how much old signal remains in the recording medium after a new write signal is applied). In some examples, polar Kerr analysis of the SUL / magnetic seed layer stack indicates that Ms increases from 319 emu / cc when deposited on top of an unoxidized pre-seed to 344 emu / cc when deposited on top of an oxidized pre-seed. In some examples, polar Kerr analysis of the SUL / magnetic seed layer stack indicates that Ms when deposited on top of an oxidized pre-seed is thus increased by 5-10% from the Ms value when deposited on top of an unoxidized pre-seed.

[0046] In block 808, the process provides additional layers of the magnetic recording medium (e.g., one or more of a SUL, a seed layer, an interlayer, an underlayer, an MRL, an overcoat layer, and a lubricant layer) on the W pre-seed layer. In one embodiment, the process can use process 500 described above to deposit the additional layers on the pre-seed layer.

[0047] In some aspects, the magnetic recording medium 300 can have a polished and oxidized pre-seed layer. Figure 9 A flowchart of a first process 900 for fabricating a magnetic recording medium having a polished and oxidized W pre-seed layer in accordance with some aspects of the present disclosure is shown. In one aspect, process 900 can be used or modified to fabricate the magnetic storage medium described above with respect to Figure 3 In some aspects, the fabricated medium can be used in data storage device 100 for Figure 1 In some aspects, the fabricated medium can be used in data storage device 100 for

[0048] In block 902, the process provides a rigid substrate (e.g., rigid substrate 302). In some aspects, the substrate can be made of one or more materials, such as an Al alloy, a NiP plated Al, a glass, a glass-ceramic, and / or combinations thereof. In block 904, the process provides a W pre-seed layer (e.g., pre-seed layer 304) on the substrate. In one embodiment, the pre-seed layer can be made of about 95 atomic percent or greater than 95 atomic percent W. In one embodiment, the W pre-seed layer has a thickness of about 12 x 10 -8resistivity of 12 x 10-6ohm-m (at 20°C) or less. In one example, the thickness of the W pre-seed layer can be less than about 14 nm.

[0049] In block 906, the process polishes the W pre-seed layer. As described above, polishing can reduce the roughness of the pre-seed layer, which can result in improved crystalline texture of subsequently deposited media films (e.g., seed layer, interlayer, underlayer, and magnetic recording layer) on the pre-seed layer, and thus increase the recording performance of the media. In block 908, the process oxidizes the W pre-seed layer. As stated above, oxidation of the pre-seed layer can improve the recording performance of the magnetic recording media. In some aspects, the oxidation of the pre-seed layer is provided in an amount sufficient to reduce intermixing between the pre-seed layer and the SUL to improve the recording performance. In one example, the magnetization (Ms) of the SUL moment can become higher and the media orientation can improve. The increase in Ms of the SUL contributes to the increase in OW2 of the media. The combination of polishing and oxidation of the pre-seed layer can further improve the recording performance of the magnetic recording media compared to using polishing or oxidation alone.

[0050] In block 910, the process provides additional layers of the magnetic recording media (e.g., one or more of the SUL, seed layer, interlayer, underlayer, MRL, overcoat layer, and lubricant layer) on the W pre-seed layer. In one embodiment, the process can use the process 500 described above to deposit the additional layers on the W pre-seed layer.

[0051] Figure 10 A flowchart of a process 1000 for fabricating a magnetic recording media having an oxidized and polished W pre-seed layer in accordance with some aspects of the present disclosure is shown. In one aspect, the process 1000 can be used or modified to fabricate the magnetic storage media described above with respect to Figure 3 In some aspects, the fabricated media can be used in the data storage device 100 of Figure 1 This process 1000 is different from the process 900 described above in the order of oxidizing and polishing the pre-seed layer.

[0052] In block 1002, the process provides a rigid substrate (e.g., the rigid substrate 302). In some aspects, the substrate can be made of one or more materials, such as Al alloy, NiP plated Al, glass, glass-ceramic, and / or combinations thereof. In block 1004, the process provides a W pre-seed layer (e.g., the pre-seed layer 304) on the substrate. In one embodiment, the W pre-seed layer can be made of about 95 atomic percent or greater than 95 atomic percent of W. In one embodiment, the W pre-seed layer has a thickness of about 12 x 10 -8 resistivity of 12 x 10-6ohm-m (at 20°C) or less. In one example, the thickness of the W pre-seed layer can be less than about 14 nm. -8 resistivity of 12 x 10-6ohm-m (at 20°C) or less. In one example, the thickness of the W pre-seed layer can be less than about 14 nm.

[0053] In block 1006, the process oxidizes the W pre-seed layer. As stated above, oxidation of the pre-seed layer can improve the recording performance of the magnetic recording medium. In some aspects, the oxidation of the pre-seed layer is provided in an amount sufficient to reduce intermixing between the pre-seed layer and the SUL to improve the recording performance. In one example, the SUL moment of magnetization (Ms) can become higher and the medium orientation can improve. The increase in Ms of the SUL contributes to an increase in OW2 of the medium. Combining polishing and oxidation of the pre-seed layer can further improve the recording performance of the magnetic recording medium. In block 1008, the process polishes the W pre-seed layer. As described above, polishing can reduce the roughness of the pre-seed layer, which can result in improved crystalline texture of subsequently deposited medium films (e.g., seed layer, interlayer, underlayer, and magnetic recording layer) on the pre-seed layer, and thus increase the recording performance of the medium.

[0054] The order of polishing and oxidation can be determined by the convenience of the operation and the smoothness that can be achieved during polishing. The two processes can be performed sequentially or simultaneously. If a sequential process with polishing followed by oxidation is employed, the conditions of polishing and oxidation can be controlled to provide a combination of the desired smoothness and oxidation level to maximize the recording performance and corrosion resistance of the magnetic recording medium. If a sequential process with oxidation followed by polishing is utilized, the oxidation and polishing conditions can be selected such that not all of the oxidized portion of the pre-seed layer is removed during polishing. If a simultaneous process is selected, a selected amount of oxygen can be used as the only gas or introduced as a secondary gas in addition to other gases or gasses (e.g., krypton or other inert gas) to achieve oxidation while polishing.

[0055] In block 1010, the process provides additional layers of the magnetic recording medium (e.g., one or more of a SUL, seed layer, interlayer, underlayer, MRL, overcoat layer, and lubricant layer) on the W pre-seed layer. In one embodiment, the process can use process 500 described above to deposit the additional layers on the W pre-seed layer.

[0056] Figure 11 An overall system 1100 is shown that can be used to deposit various layers on a substrate to form a magnetic recording medium and to selectively polish and / or oxidize a substrate or a layer on a substrate (e.g., a pre-seed layer). Briefly, the system 1100 includes a deposition apparatus 1102 configured to deposit a pre-seed layer and additional layers of a magnetic recording medium 300 onto a substrate (e.g., substrate 302). The deposition apparatus 1102 can be, for example, configured to perform one or more of: PVD, DC magnetron sputter deposition, ion beam deposition, radio frequency sputter deposition, or CVD, including PECVD, LPCVD, and ALCVD. The deposition apparatus 1102 can include one or more individual apparatus stations, components, or systems for depositing different layers. One example of such a deposition system is the Intevac, Inc. 200 Lean. In conjunction with the deposition apparatus 1102, the system 1100 can include a polishing apparatus 1104 configured to polish a pre-seed layer on a substrate (e.g., substrate 302). The polishing apparatus 1104 can be, for example, configured to perform one or more of: chemical mechanical polishing (CMP), mechanical polishing, or electrochemical mechanical polishing (ECMP).Figure 11 the system of Figures 4 to 10 any one of the methods of Figure 3 the medium of

[0057] The system 1100 can include an oxygen source 1104. Oxygen can be introduced into a deposition chamber of the deposition apparatus 1102 while (or after) the W pre-seed layer is formed so as to oxidize the pre-seed layer. In one embodiment, the deposition apparatus 1102 can deposit the W pre-seed layer in the presence of oxygen supplied by the oxygen source 1104 to oxidize the pre-seed layer by some desired amount (which can be controlled by the amount of oxygen introduced into the chamber and other factors such as deposition temperature, etc.). In one example, where the deposition apparatus is a DC magnetron apparatus operating at a temperature of 50 degrees Celsius, the oxygen source is configured to provide a flow of oxygen into the deposition apparatus for a duration of time set to produce a thickness of oxidized metal within the pre-seed layer and / or an oxygen concentration in the oxidized metal within the pre-seed layer such that the areal density capacity (ADC) of the magnetic recording medium is greater than at least 0.5% of the ADC for a corresponding magnetic recording medium having a pre-seed layer that is not oxidized. The oxygen source 1104 is then turned off and other components (such as a vacuum pump, not shown) can be used to evacuate the oxygen from the deposition chamber of the deposition apparatus 1102 and create a vacuum therein (if appropriate for depositing the remaining layers). In some examples, an inert gas can be introduced into the chamber (if appropriate for depositing the remaining layers). Thus, in some examples, the deposition of the pre-seed layer can be selectively performed in the presence of both an inert gas and oxygen.

[0058] The system 1100 can include a polishing apparatus 1106, including or consisting of a modified carbon etch / deposition apparatus configured without a carbon source so as to produce an inert gas plasma (without carbon particles) for polishing a substrate or pre-seed layer (or other structure or layer). In this regard, a carbon etch / deposition apparatus typically includes a cathode (with a source of carbon material), an anode, and a plasma generation system within a sealed chamber. These components are configured and controlled such that, in use, carbon particles are emitted from the cathode and travel within an ignition plasma in the chamber and accelerate toward the anode, upon which a structure to be coated or etched (such as a substrate) is positioned. The carbon particles strike (or bombard or impact) the structure and deposit a carbon coating onto the target structure, or if the apparatus is so configured, leave an etch pattern. Magnetic containment components can be provided to contain the plasma and to direct the carbon particles in a controlled manner within the chamber.

[0059] The polishing apparatus 1106 can be a modified version of such an apparatus modified to omit the carbon source from the cathode and to inject an inert gas, such as a krypton gas source, into its chamber for polishing a structure, such as a pre-seed layer on a substrate. In use, when the plasma is ignited, inert gas atoms and ions accelerate toward the structure to be polished, which can be adjacent to the anode. The inert gas atoms and ions strike (or bombard or impact) the structure and thereby polish the structure by knocking off (or otherwise moving away) atoms, particles, or other material from the surface of the structure, such as atoms, particles, or material protruding from the surface (and thus contributing to a rough surface). A bias voltage between the plasma generation source and the substrate and / or a voltage between the anode and the cathode can be controlled to select or adjust an amount of polishing to be performed to achieve a desired smoothness or roughness, such as a surface smoothness or roughness below a predetermined smoothness or roughness threshold. For example, a higher magnitude bias voltage and / or voltage can be used to perform a "strong" polishing, whereas a lower magnitude bias voltage and / or voltage can be used to perform a "mid-level" polishing. Additionally or alternatively, an amount of time for which polishing is applied can be adjusted to control an amount of polishing, or a plasma density can be adjusted to control an amount of polishing. Alternatively, a DC magnetron (which uses a target) can be used to polish the structure (although with a DC magnetron, some non-desired particles or material from the target can be deposited on the structure being polished). An RF sputtering station or other plasma system can also be used, so long as it can be adapted to smooth a surface.

[0060] In one embodiment, the polishing apparatus 1106 can be controlled to polish a W pre-seed layer, such as the pre-seed layer 304, to a desired smoothness. The substrate (with the smooth pre-seed layer) is then transferred back to the deposition apparatus 1102 to deposit additional layers of magnetic recording media, such as one or more of a SUL, a seed layer, an interlayer, a bottom layer, an MRL, an overcoat layer, and a lubricant layer. In other examples, if the deposition apparatus is suitably equipped, polishing can be performed within the same deposition apparatus that deposits the pre-seed layer and other layers.

[0061] In one aspect, each of the above processes can perform the sequence of actions in a different order. In another aspect, each process can skip one or more of the actions. In other aspects, one or more of the actions are performed simultaneously. In some aspects, additional actions can be performed.

[0062] Additional Aspects

[0063] The examples set forth herein are to demonstrate certain concepts of the disclosure. The apparatus, devices, or components shown in the preceding figures can be configured to perform one or more of the methods, features, or steps described herein. One skilled in the art will appreciate that the examples given are intended for illustration only and that the disclosure is not limited to any of the examples set forth. Based on the teachings herein one skilled in the art should appreciate that an aspect disclosed herein can be implemented independently of any other aspects. Two or more aspects can be implemented together.

[0064] Aspects of the disclosure have been described above with reference to schematic flowcharts and / or schematic block diagrams of methods, apparatus, systems, and computer program products according to aspects of the present disclosure. It is understood that each block of the schematic flowcharts and / or schematic block diagrams, and combinations of blocks in the schematic flowcharts and / or schematic block diagrams, can be implemented by computer program instructions. Such computer program instructions can be provided to a processor of a computer or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions and / or acts specified in the block or blocks.

[0065] The subject matter described herein can be implemented in hardware, software, firmware, or any combination thereof. As such, the terms "function," "module," and the like as used herein can refer to hardware, which can also include software and / or firmware components, that are employed to facilitate the functionality of the described components. In one example implementation, the subject matter described herein can be implemented using a computer readable medium having computer executable instructions stored therein, which, when executed by a computer (e.g., a processor), control the computer to implement the functionality described herein. Examples of computer readable mediums suitable for implementing the subject matter described herein include non-transitory computer readable mediums, such as disk memory devices, chip memory devices, programmable logic devices, and application specific integrated circuits. Additionally, the computer readable medium that implements the subject matter described herein can be located in a single device or computing platform or can be distributed across multiple devices or computing platforms.

[0066] It should also be noted that in some alternative implementations, the functions noted in the blocks can occur out of the order noted in the figures. For example, two blocks noted in succession can in fact be executed substantially concurrently or the blocks can sometimes be executed in the reverse order, depending upon the functionality involved. These and other variations are contemplated herein. Other steps and methods can be conceived that are functionally, logically, or otherwise equivalent to those shown in the figures and described herein. Although various arrow types and line types can be employed in the flowchart and / or block diagrams, these are merely meant as an example, and one of ordinary skill in the art will recognize that the described aspects can be carried out with a wide variety of arrows, lines, and / or portions of arrows or lines connecting the elements, in a manner not specifically shown in the drawings.

[0067] The various features and processes described above can be used independently of one another or can be combined in various ways. All possible combinations and subcombinations are intended to fall within the scope of the present disclosure. In addition, certain method, event, state, or process blocks can be omitted in some implementations. The methods and processes described herein are also not limited to any particular sequence, and the blocks or states relating thereto can be performed in other sequences that are not specifically illustrated, unless expressly stated otherwise. For example, the tasks or events described can be performed in an order different from specifically disclosed, or multiple tasks or events can be combined in a single block or state. The example tasks or events can be performed in serial, in parallel, or in some other manner. Tasks or events can be added to or removed from the disclosed example aspects. The example systems and components described herein can be configured differently than described. For example, elements can be added to, removed from, or rearranged relative to the disclosed example aspects.

[0068] Those skilled in the art will appreciate that information and signals can be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that can be referenced throughout the above description can be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0069] The word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any aspect described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other aspects. Likewise, the term "aspects" does not require that all aspects include the discussed feature, advantage, or mode of operation.

[0070] While the foregoing description contains many specific aspects of the application, these should not be construed as limiting the scope of the application, but merely as illustrations of particular aspects. Accordingly, the scope of the application should be determined not by the aspects illustrated, but by the appended claims and their equivalents. Furthermore, the use of "a", "an", or "the" to describe the various aspects described herein are used in the sense of "at least one" unless otherwise specified. In other words, one or more of any element, feature, structure, or characteristic described herein can be included in a particular aspect, and aspects can be combined in any and all combinations unless otherwise indicated.

[0071] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of embodiments. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" "comprising", "includes" and / or "including", when used herein, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. That is, these terms can specify the presence of stated features, integers, steps, operations, elements, components, or a group thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or groups thereof. Moreover, it is understood that the word "or" has the same meaning as the Boolean operator "OR", that is, it encompasses either "any" or "all" possibilities unless otherwise indicated. It is also understood that the symbol " / " between two adjacent words has the same meaning as "or". Furthermore, unless otherwise indicated, the word "comprises" and variations thereof such as "comprising" or "comprises" are not intended to exclude the presence of one or more additional features, integers, steps, operations, elements, components or groups thereof but to add additional features, integers, steps, operations, elements, components or groups thereof to the device or process described herein.

[0072] The use of names such as "first," "second," etc., to refer to elements herein does not generally limit the quantity or order of those elements. In fact, these names may be used herein as a convenient way to distinguish two or more elements or examples of elements. Therefore, references to first and second elements do not imply that only two elements may be used herein, or that the first element must precede the second element in some way. Furthermore, unless otherwise stated, a group of elements may comprise one or more elements. Additionally, the terms "at least one of a, b, or c" or "a, b, c, or any combination thereof" as used in the description or claims mean "a or b or c, or any combination of these elements." For example, this term may include a, or b, or c, or a and b, or a and c, or a and b and c, or 2a, or 2b, or 2c, or 2a and b, etc.

[0073] As used herein, the term "determine" encompasses a wide variety of actions. For example, "determine" can include operations, calculations, processing, derivation, investigation, searching (e.g., looking in a table, database, or other data structure), confirmation, and so on. Additionally, "determine" can include receiving (e.g., receiving information), accessing (e.g., accessing data in memory), and the like. Furthermore, "determine" can include parsing, selecting, picking, building, and the like.

Claims

1. A magnetic recording medium, comprising: a rigid substrate; a pre-seed layer on the rigid substrate, the pre-seed layer comprising W and an oxide of W; an amorphous soft underlayer (SUL) on the pre-seed layer; a seed layer on the amorphous SUL; and a magnetic recording layer (MRL) on the seed layer.

3. The magnetic recording medium of claim 2, wherein a thickness of the pre-seed layer is less than 30 nm.

2. The magnetic recording medium according to claim 1, wherein the resistivity of the pre-seed layer is 12 x 10 -8 ohm meter (Ω-m) or less.

4. The magnetic recording medium of claim 3, wherein the thickness of the pre-seed layer is 14 nm or less.

5. The magnetic recording medium of claim 1, wherein an electrical conductivity of the pre-seed layer having a first thickness is configured to be higher than an electrical conductivity of a pre-seed layer comprising Cr and Ti having the first thickness.

6. The magnetic recording medium of claim 1, wherein the pre-seed layer comprises at least 95 atomic percent W.

7. The magnetic recording medium of claim 1, wherein the amorphous SUL comprises CoFe, and one or more elements selected from the group consisting of Mo, Nb, Ta, W, B, Zr, and combinations thereof.

8. The magnetic recording medium of claim 7, wherein the amorphous SUL does not contain Cr.

9. The magnetic recording medium of claim 1, wherein the pre-seed layer comprises at least 95 atomic percent W. wherein the resistivity of the pre-seed layer is 12 x 10 -8 ohm millimeter (Ω.m) or less, and 10. A data storage device, comprising: a slider comprising a head; and the magnetic recording medium of claim 1, wherein the slider is configured to write information to the magnetic recording layer of the magnetic recording medium.

11. A method for manufacturing a magnetic recording medium, the method comprising: providing a rigid substrate; providing a pre-seed layer on the rigid substrate, the pre-seed layer comprising W and an oxide of W; providing an amorphous soft underlayer (SUL) on the pre-seed layer; providing a seed layer on the amorphous SUL; and providing a magnetic recording layer (MRL) on the seed layer.

12. The method of claim 11, further comprising at least one of: polishing the pre-seed layer; or oxidizing the pre-seed layer.

13. The method of claim 11, further comprising: polishing the pre-seed layer; and oxidizing the pre-seed layer after polishing the pre-seed layer.

14. The method of claim 11, further comprising: oxidizing the pre-seed layer; and polishing the pre-seed layer after oxidizing the pre-seed layer.

16. The method of claim 15, wherein a thickness of the pre-seed layer is less than 30 nm.

17. The method of claim 16, wherein the thickness of the pre-seed layer is 14 nm or less.

18. The method of claim 11, wherein an electrical conductivity of the pre-seed layer having a first thickness is configured to be higher than an electrical conductivity of a pre-seed layer comprising Cr and Ti having the first thickness.

19. The method of claim 11, wherein the pre-seed layer comprises at least 95 atomic percent W.

15. The method of claim 11, wherein the pre-seed layer has a resistivity of 12 x 10 -8 ohm-m (Ω-m) or less. ​ ​ ​ ​ 20. The method of claim 11, wherein the amorphous SUL comprises Co, Fe, and one or more elements selected from the group consisting of: Mo, Nb, Ta, W, B, Zr, and combinations thereof.

21. The method of claim 20, wherein the amorphous SUL does not include Cr.

22. The method of claim 11, wherein the resistivity of the pre-seed layer is 12 x 10 -8 ohm millimeter (Ω.m) or less, and wherein the pre-seed layer comprises at least 95 atomic percent W.

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