Magnetic recording media with sacrificial layer and corresponding etching process to minimize head-to-media pitch

Abstract

Various apparatuses, systems, methods, and media are disclosed to provide a thermally assisted magnetic recording (HAMR) media that includes a sacrificial layer and a corresponding etching process that minimizes head-to-media pitch. The medium may include the sacrificial layer and capping layer, where each of the layers is etched to reduce roughness. The sacrificial layer is configured to ensure an etch rate that allows selective etching and may be deposited on the capping layer and may remain along a grain boundary of the capping layer after etching. The remainder of the sacrificial layer may form a discontinuous layer including layer segments positioned along grain boundaries of the capping layer. The sacrificial layer may be made of a non-magnetic material different from a material of the capping layer or a material of a protective layer deposited on the etched capping layer.

Description

Technical Field

[0001] In some aspects, the present disclosure relates to magnetic recording media. More particularly, but not exclusively, the present disclosure relates to magnetic recording media configured with a sacrificial layer and corresponding etching methods that minimize head-to-media spacing. Background Art

[0002] Magnetic storage systems such as hard disk drives (HDDs) are used in a 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 disk drives, high definition television (HDTV) receivers, television set-top boxes, video game controllers, and portable media players.

[0003] A typical disk drive includes a magnetic storage medium in the form of one or more flat disks. The disk is usually formed of a few main substances, namely a substrate material that gives it structure and rigidity, a magnetic recording layer that holds the magnetic pulses or magnetic moments that store digital data, and a media protection layer and a lubricant layer to protect the magnetic recording layer. 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 moments stored on the recording layer of the disk.

[0004] Heat-assisted magnetic recording (HAMR) systems can increase the areal density of information recorded magnetically on various magnetic media. To achieve higher areal densities for magnetic storage, smaller magnetic grain sizes, such as less than 6 nanometers (nm), may be required. In HAMR, high temperatures are applied to the media during the write process to facilitate recording to small magnetic grains. High temperatures can be achieved using a near-field transducer of a laser diode coupled to a slider within a HAMR disk drive.

[0005] A smooth media interface is important for achieving high areal density and reducing flying height. In the case of HAMR media, the magnetic grain topology grown at high temperatures is typically not smooth. The capping layer and carbon protective layer conform to the media grain structure beneath them, resulting in a relatively high roughness (e.g., about 6 to 8 angstroms) at the media interface. Therefore, more carbon protective layers (e.g., increased thickness) are required to ensure that the media has sufficient smoothness to pass standard media performance benchmarks. In this case, the magnetic spacing (the distance between the recording layer grains and the head) is made relatively large by using a thick carbon protective layer, and the recording performance is significantly reduced. Aspects of the present disclosure are intended to address these and other problems. Summary of the invention

[0006] A brief overview of some aspects of the disclosure is presented below to provide a basic understanding of these aspects. This overview is not an extensive overview of all contemplated features of the disclosure, and is neither intended to identify key or important elements of all aspects of the disclosure, nor to delineate the scope of any or all aspects of the disclosure. Its sole purpose is to present various concepts of some aspects of the disclosure in a simplified form as a preface to a more detailed description presented later.

[0007] In one aspect, the present disclosure provides a magnetic recording medium, which includes: a substrate; a heat sink layer, which is located on the substrate; a magnetic recording layer (MRL), which is located on the heat sink layer, the MRL including a plurality of recording grains, which are separated by separators at grain boundaries of the plurality of recording grains; a capping layer, which is located on the MRL and includes magnetic material at positions corresponding to the plurality of recording grains and capping separators at positions corresponding to the grain boundaries; and a sacrificial layer, which is embedded in the capping layer at a position corresponding to the grain boundary, the sacrificial layer including a non-magnetic material different from the capping separators, wherein a top surface of the capping layer and a top surface of the sacrificial layer are substantially coplanar.

[0008] In another aspect, the present disclosure provides a magnetic recording medium, which includes: a substrate; a heat sink layer, which is located on the substrate; a magnetic recording layer (MRL), which is located on the heat sink layer, the MRL including a plurality of recording grains, the plurality of recording grains being separated by separators at the grain boundaries of the plurality of recording grains; a capping layer, which is located on the MRL and includes a magnetic material arranged on each of the plurality of recording grains and another material arranged at the grain boundaries; a discontinuous sacrificial layer, which includes a plurality of segments, each of which is located on the capping layer at a position corresponding to the grain boundaries, the sacrificial layer including a material different from that of the capping layer; a protective layer, which is located on the capping layer; and a lubricant layer, which is located on the protective layer.

[0009] In another aspect, the present disclosure provides a method for manufacturing a magnetic recording medium, the method comprising: providing a substrate; providing a heat sink layer on the substrate; providing a magnetic recording layer (MRL) on the heat sink layer; providing a capping layer on the MRL, the capping layer comprising a magnetic material; providing a sacrificial layer on the capping layer, the sacrificial layer comprising a material different from the magnetic material of the capping layer; etching the sacrificial layer and a portion of the capping layer; and providing a protective layer on the etched sacrificial layer and the etched portion of the capping layer.

[0010] By reading the subsequent detailed description, these and other aspects of the present disclosure will be more fully understood. By reading the following description of the specific embodiments of the present disclosure in conjunction with the accompanying drawings, other aspects, features and specific implementations of the present disclosure will become apparent to those of ordinary skill in the art. Although the features of the present disclosure can be discussed with respect to certain specific implementations and the accompanying drawings below, all specific implementations of the present disclosure may include one or more of the advantageous features discussed herein. In other words, although one or more specific implementations may be discussed as having certain advantageous features, one or more of these features may also be used according to the various specific implementations of the present disclosure discussed herein. Similarly, although certain specific implementations may be discussed below as device specific implementations, system specific implementations or method specific implementations, it should be understood that such specific implementations may be implemented in various devices, systems and methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] A more specific description is included below with reference to specific aspects shown in the accompanying drawings. Understanding that these drawings depict only certain aspects of the disclosure and are therefore not to be considered limiting of its scope, the disclosure is described and explained with additional specificity and detail through the use of the accompanying drawings, in which:

[0012] Figure 1 is a top schematic diagram of an exemplary data storage device configured for heat-assisted magnetic recording (HAMR) including a slider and HAMR media with an etched sacrificial layer and a reduced head-to-media spacing according to aspects of the present disclosure.

[0013] Figure 2 According to aspects of the present disclosure Figure 1 Schematic side view of an exemplary slider and HAMR medium.

[0014] Figure 3 is a schematic side view of an exemplary HAMR media including, among other layers, a discontinuous sacrificial layer and a capping layer that are each etched to reduce head-to-media spacing according to aspects of the present disclosure.

[0015] Figure 4 is a schematic side view of an exemplary HAMR media including, among other layers, a discontinuous sacrificial layer and a capping layer that are each etched to reduce the head-to-media spacing and the grain structure of the magnetic recording layer according to aspects of the present disclosure.

[0016] Figures 5a to 5i A series of cross-sectional views of a magnetic media workpiece and corresponding actions performed on the magnetic media workpiece in a process for reducing the surface roughness of the magnetic media using selective etching of sacrificial and capping layers in accordance with aspects of the present disclosure are shown.

[0017] Figure 6 is a flow chart of an exemplary process for fabricating a HAMR medium including a sacrificial layer and a capping layer, wherein the process etches both the sacrificial layer and the capping layer to reduce roughness, according to aspects of the present disclosure.

[0018] Figure 7 is a graph showing exemplary average roughness and coercivity values ​​for a first test medium without a sacrificial layer and without an etch, a second test medium with a capping layer and an etch of the capping layer but without a sacrificial layer, and a third test medium with a sacrificial layer and a capping layer and an etch of both the sacrificial layer and the capping layer according to aspects of the present disclosure.

[0019] Figure 8 is a graph showing exemplary X-ray diffraction characterization data according to aspects of the present disclosure, including Figure 7 The (002) peak intensity of the magnetic grains within each of the same three test media.

[0020] Fig. 9 is a graph showing read signal-to-noise ratio gain versus protective layer deposition time for a first test medium without an etch of a sacrificial layer and a capping layer, a second test medium with an etch of a sacrificial layer and a capping layer, and a second test medium with an etch of both a sacrificial layer and a capping layer according to aspects of the present disclosure.

[0021] Fig.10 is a graph showing slip versus protective layer thickness for a first test medium without an etch of a sacrificial layer and a capping layer, and a second test medium with an etch of a sacrificial layer and a capping layer, and both sacrificial layers and a capping layer, according to aspects of the present disclosure. DETAILED DESCRIPTION

[0022] In the following detailed description, reference is made to the accompanying drawings that form a part of the detailed description. In addition to the exemplary aspects, aspects and features described above, other aspects, aspects and features will become apparent by reference to the accompanying drawings and the following detailed description. The description of the elements in each figure can refer to the elements of the previous figures. The same numbers can refer to the same elements in the drawings, including alternative aspects of the same elements.

[0023] In some aspects, the present disclosure relates to various apparatus, systems, methods, and media for providing magnetic recording media, such as heat-assisted magnetic recording (HAMR) media, that can provide, among other features, optimized or at least improved magnetic properties within HAMR media. It is noted that HAMR is a type of energy-assisted magnetic recording (EAMR), which is a broad term that encompasses HAMR as well as microwave-assisted magnetic recording (MAMR). At least some aspects of the present disclosure are not limited to HAMR and are applicable to EAMR.

[0024] As mentioned in the introduction above, the head-to-medium spacing needs to be minimized to achieve acceptable or optimized recording performance in the magnetic medium. Based on the non-uniform (e.g., rough) topology of the magnetic grains grown at high temperatures for HAMR, there are challenges in reducing the roughness at the medium surface (e.g., medium interface) above the magnetic grains. Various aspects of the present disclosure relate to HAMR media including a sacrificial layer and a capping layer, wherein each of these layers is etched to reduce the roughness (e.g., the roughness caused by the underlying magnetic grains) and thereby increase the smoothness at the medium interface. The sacrificial layer is configured to ensure an etching rate that allows selective etching (e.g., etching only selected components of the medium, such as the sacrificial layer and the capping layer, without etching the magnetic grains). The sacrificial layer may be deposited on the capping layer, and after etching (e.g., using plasma etching with an inert gas), the sacrificial layer may be retained along the grain boundaries of the capping layer. The remaining portion of the sacrificial layer may form a discontinuous layer including a plurality of segments positioned along the grain boundaries of the capping layer. The sacrificial layer may be made of a material different from that of the capping layer or the material of the protective layer deposited on the etched capping layer (e.g., a non-magnetic material). In one aspect, the sacrificial layer may be embedded in the capping layer at a location corresponding to a grain boundary, wherein the top surface of the capping layer (particularly the capping grain) and the top surface of the sacrificial layer are substantially coplanar.

[0025] Performance testing of HAMR media with a sacrificial layer showed multiple beneficial properties compared to other media designs without a sacrificial layer. For example, the testing showed that HAMR media with a sacrificial layer had a reduced average roughness of the media surface, no damage to the magnetic grain peaks, better signal-to-noise ratio for read operations (e.g., up to 1.8 decibels (dB)), and sufficient slip percentage with a thinner protective layer. The testing showed that other media designs that etched the capping layer without a sacrificial layer damaged the magnetic grains (perhaps through some partial etching), and thereby damaged the recording / magnetic grains, and thus reduced the magnetic recording performance. In a surprising result, the testing showed that HAMR media with an etched sacrificial layer did not damage the magnetic grains, maintained the high strength of the grain peaks, and thus provided better magnetic recording performance than other media designs.

[0026] Illustrative Examples and Implementations

[0027] Figure 1 1 is a top schematic diagram of an exemplary data storage device (e.g., a disk drive or magnetic recording device) configured for heat-assisted magnetic recording (HAMR) according to aspects of the present disclosure, the exemplary data storage device including a slider 108 and a HAMR medium 102 having an etched sacrificial layer and a reduced head-to-media spacing. Figure 1 Not visible in, but can be seen in Figure 2114) is positioned with a head / slider 108. The disk drive 100 may include one or more disks / media 102 to store data. The disks / media 102 reside on a spindle assembly 104, which is mounted to a drive housing 106. Data may be stored along tracks in the magnetic recording layer of the disks 102. Reading and writing of data is accomplished with a head 108 (slider) that may have both a read element and a write element (108a and 108b). The write element 108a is used to change the properties of the magnetic recording layer of the disk 102 and thereby write information thereto. In one aspect, the head 108 may have a magnetoresistive (MR) based element, such as a tunnel magnetoresistive (TMR) element for reading, and a write pole with a coil that may be energized for writing. In operation, a spindle motor (not shown) rotates the spindle assembly 104, and thus the disks 102, to position the head 108 at a specific location along a desired disk track 107. The position of the head 108 relative to the disk 102 may be controlled by a control circuit system 110 (e.g., a microcontroller). Note that while an exemplary HAMR system is shown, at least some aspects of the present disclosure may be used in other HAMR or EAMR magnetic data recording systems or in non-HAMR or non-EAMR magnetic data recording systems, including shingled magnetic recording (SMR) media, perpendicular magnetic recording (PMR) media, or microwave assisted magnetic recording (MAMR) media.

[0028] Figure 2 yes Figure 1 1 and 102. The magnetic recording medium 102 includes an etched sacrificial layer and a capping layer above the magnetic recording layer (the layers are Figure 2 Invisible, but visible Figure 3 and Figure 4 ). The slider 108 can include a submount 112 attached to the top surface of the slider 108. The laser 114 can be attached to the submount 112 and possibly to the slider 108. The slider 108 includes a writing element (e.g., a writer) 108a and a reading element (e.g., a reader) 108b positioned along an air bearing surface (ABS) 108c of the slider to write information to and read information from the medium 102, respectively. In other aspects, the slider can also include a layer of Si or Si cladding 120. This layer is optional.

[0029] In operation, the laser 114 is configured to generate and direct optical energy to a waveguide in the slider (e.g., along the dashed line), which directs the light to a near field transducer (NFT) 122 proximate to an air bearing surface (e.g., bottom surface) 108c of the slider 108. Upon receiving light from the laser 114 via the waveguide, the NFT 122 generates localized thermal energy that heats a portion of the medium 102 within or proximate to both the writing element 108a and the reading element 108b. The expected recording temperature is in the range of approximately 350°C to 400°C. Figure 2 In the illustrated aspect, the laser directed light is disposed within the writer 108a and proximate the trailing edge of the slider. In other aspects, the laser directed light may instead be positioned between the writer 108a and the reader 108b. Figure 1 and Figure 2 A specific example of a HAMR system is shown. In other examples, the magnetic recording medium 102 can be used in other suitable HAMR systems (eg, with other sliders configured for HAMR).

[0030] Figure 3 is a schematic side view of an exemplary HAMR medium 300 including, among other layers, a discontinuous sacrificial layer 314 and a capping layer 312 that are each etched to reduce head-to-medium spacing according to aspects of the present disclosure. Figure 3 The HAMR medium 300 has a stacked structure having a substrate 302 at the bottom / base layer, a soft underlayer (SUL) 304 on the substrate 302, a heat sink layer 306 (which may be formed, for example, of Cr) on the SUL 304, a seed layer 308 on the heat sink layer 306, a magnetic recording layer (MRL) 310 (which may be formed of magnetic grains (e.g., FePt) and one or more segregants) on the seed layer 308, a capping layer 312 (which may be formed of a magnetic material (e.g., CoFe or CoPt) and one or more segregants) on the MRL 310, a discontinuous sacrificial layer 314 (e.g., made of C or other suitable materials) on the capping layer 312, a protective layer 316 (e.g., made of diamond-like carbon (DLC) or other suitable materials) on the sacrificial layer 314 (and possibly on the capping layer 312), and a lubricant layer 318 on the protective layer 316.

[0031] As described in further detail below, the sacrificial layer 314 is deposited on the capping layer 312 and then etched, wherein both the sacrificial layer 314 and the capping layer 312 are etched and, as a result, the sacrificial layer 314 becomes discontinuous such that it is composed of a plurality of segments that are each positioned along grain boundaries corresponding to grain boundaries between magnetic / recording grains established in the MRL 310. The sacrificial layer 314 may be made of a non-magnetic material that is different from the capping layer 312 material (e.g., different from the capping layer magnetic material or separator).

[0032] In some aspects, HAMR medium 300 may include additional layers. In one example, HAMR medium 300 also includes an adhesion layer (which may be formed, for example, of NiTa) on substrate 302 and below SUL 304. In one example, HAMR medium 300 also includes a (heat dissipating) seed layer (which may be formed, for example, of RuAl) on SUL 304 and below heat sink layer 306.

[0033] It is noted that as used herein, the terms "over", "under", "on", and "between" refer to the relative position of one layer with respect to other layers. Thus, a layer deposited or disposed on, over, or under another layer may be in direct contact with the other layer, or may have one or more intervening layers. Additionally, a layer deposited or disposed between layers may be in direct contact with the layers, or may have one or more intervening layers.

[0034] Figure 4 4 is a schematic side view of an exemplary HAMR medium 400 including, among other layers, a discontinuous sacrificial layer 414 and a capping layer 412, each of which is etched to reduce the head-to-media spacing and the grain structure of the magnetic recording layer 410, according to aspects of the present disclosure. Figure 3 HAMR medium, Figure 4The HAMR medium 400 has a stacked structure having a substrate 402 at the bottom / base layer, a soft / amorphous underlayer (SUL) 404 on the substrate 402, a heat sink layer 406 (which may be made of Cr, for example) on the SUL 404, a seed layer 408 on the heat sink layer 406, a magnetic recording layer (MRL) 410 (which may be formed of magnetic grains 410a (e.g., FePt) and one or more separators 410b) on the seed layer 408, and a magnetic recording layer (MRL) 410 on the MRL. A capping layer 412 on 410 (which may be made of a magnetic material 412a (capping grains, e.g., CoFe) and one or more separators 412b on the MRL grains 410a), a discontinuous sacrificial layer 414 on the capping layer 412 (e.g., made of C or other suitable materials), a protective layer 416 on the sacrificial layer 414 and on the capping layer grains 412a (e.g., made of diamond-like carbon (DLC) or other suitable materials), and a lubricant layer 418 on the protective layer 416.

[0035] During media manufacturing, MRL 410 is deposited such that recording grains 410a are formed of one or more magnetic materials (e.g., FePt) and grain boundaries 410b are formed of one or more separators (e.g., C, BN, SiO2, Ag, or TiO2). Note that while MRL 410 is abstractly drawn as a single layer, it may include multiple layers, as previously shown in MRL 310, and in one example, the depicted recording grains 410a and grain separators 410b may represent the topmost layer of a multilayer MRL structure. Capping layer 412 is then deposited on MRL 410 such that capping grains 412a are formed of one or more magnetic materials (e.g., CoFe) on MRL grains 410a, and capping boundaries 412b are formed of one or more capping separators on MRL separators 410b. MRL grains 410a and capping grains 412a may present a fairly rough upper surface. To reduce the roughness caused by grain formation, a sacrificial layer 414 is deposited on the capping layer 412 and etched until at least some of the capping grains 412a have been planarized, as shown in FIG. Figure 4 Thus, the top of the capping die 412a has been etched to be substantially flat and coplanar with the remainder of the sacrificial layer 414 (which is now discontinuous or segmented).

[0036] In one aspect, etching is accomplished using a plasma enhanced etching process utilizing an inert gas. In one aspect, the remaining sacrificial layer 414 is chemically mixed with the capping separator 412b at the grain boundary. In one aspect, the remaining sacrificial layer 414 is embedded in the capping layer 412, and more specifically, in the capping layer separator 412b. In one aspect, either the sacrificial layer 414 or the capping layer 412 has an embedded residue of the inert gas used in the etching process.

[0037] In one aspect, the protective layer 416 is made of amorphous hydrogenated carbon (such as diamond-like carbon (DLC) or non-hydrogenated tetrahedral amorphous carbon (ta-C)), and the sacrificial layer 414 is made of C having properties different from those of the protective layer 416 (e.g., the protective layer after etching). For example, the DLC may be made of hydrogenated carbon having about 30% sp3 bonded atoms and about 70% sp2 bonded atoms, while the C of the sacrificial layer 414 may be made of about 5% sp3 bonded atoms and about 95% sp2 bonded atoms (e.g., after etching), which is also different from the as-deposited state. In one aspect, for example, a sacrificial layer having about 70% sp2 bonded atoms is deposited, which increases to about 95% after etching. In one aspect, the sacrificial layer 414 is made of at least one of C, SiO2, Al2O3, ZrO2, or TiO2. In one aspect, the sp2 percentage is the percentage of sp2 / (sp2+sp3) bonds, and the sp3 percentage is the percentage of sp3 / (sp2+sp3) bonds.

[0038] In one aspect, each of the sacrificial layer 414 and the capping layer 412 includes a remnant of an inert gas used in the etching process, and the inert gas includes at least one of Kr, Ar, or Xe.

[0039] In one aspect, the thickness of the sacrificial layer 414 is less than the thickness of the capping layer 412 .

[0040] In some aspects, the top surface of the capping layer 412 and the top surface of the sacrificial layer 414 are substantially planar (eg, with a deviation from being exactly planar of no more than In one example, the top surfaces of the capping layer 412 and the sacrificial layer 414 are substantially coplanar (eg, the deviation from exact coplanarity is no more than 1 / 2). ).

[0041] Figure 4 The HAMR media 400 has a reduced surface roughness at the capping layer 412 , and therefore, the thickness of the protective layer 416 and the lubricant layer 418 may be reduced to reduce or minimize the head-to-media spacing 430 .

[0042] In some aspects, the layers in the dielectric may have the following thicknesses: substrate 302 / 402 thickness in the range of 0.5 millimeters (mm) to 0.635 mm; SUL 304 / 404 thickness in the range of 85 nanometers (nm) to 130 nm; heat sink layer 306 / 406 thickness in the range of 55 nm to 100 nm; seed layer 308 / 408 thickness in the range of 1 nm to 4 nm; MRL 310 / 410 thickness in the range of 8 nm to 11 nm; capping layer 312 / 412 thickness in the range of 1 nm to 3 nm; sacrificial layer 314 / 414 thickness in the range of 0.5 nm to 1.5 nm; protective layer 416 thickness in the range of 1 nm to 3 nm. to The lubricant layer thickness (if provided) is within to Additionally, based on the specific characteristics of the system (such as its operating temperature, desired data area density, etc.), routine experimentation can be used to determine suitable or preferred layer thicknesses and / or suitable or preferred compound percentage concentrations for use in an actual HAMR system.

[0043] In some examples, the substrate 302 / 402 has an outer diameter (i.e., OD) of about 97 mm and a thickness of about 0.5 mm. In other examples, the OD may be 95 mm or 95.1 mm. (Generally, such disks are referred to as "3.5 inch" disks.) In some aspects, the substrate 302 / 402 may be made of one or more materials such as Al alloy, Al plated with NiP, glass, glass ceramic, and / or combinations thereof.

[0044] In some aspects, the medium further includes an adhesion layer (which may alternatively be referred to as a pre-seed layer) that is used to reduce delamination of layers or films deposited over the adhesion layer. The adhesion layer may be a metal alloy such as NiTa, CrTi, or the like.

[0045] In some aspects, the SUL 304 / 404 may be made of one or more materials such as Co, Fe, Mo, Ta, Nb, B, Cr, or other soft magnetic materials, or combinations thereof. The SUL 304 / 404 may include an amorphous compound to which one or more elements from Mo, Nb, Ta, W, and B are added, or a combination of Co and Fe (e.g., a CoFe alloy). The SUL 304 / 404 may be configured to support the magnetization of the magnetic recording layer structure 310 / 410 during data storage operations. More specifically, the SUL 304 / 404 may be configured to provide a return path for a magnetic field applied during a write operation.

[0046] In some aspects, the media also includes a (heat sink) seed layer to create a growth template for subsequently deposited films, including heat sink layers 306 / 406 and MRLs 310 / 410. Functional goals of the (heat sink) seed layer include small grain size and good crystallographic texture, both of which may be desirable for good media recording performance.

[0047] In some aspects, the heat sink layer 306 / 406 may be made of one or more materials such as Cr (as shown) or Ag, Al, Au, Cu, Mo, Ru, W, CuZr, MoCu, AgPd, CrRu, CrV, CrW, CrMo, CrNd, NiAl, NiTa, combinations thereof, and / or other suitable materials known in the art.

[0048] In some aspects, the dielectric further includes a thermal resistance layer deposited directly on the heat sink layer 306 / 406 to provide thermal resistance to the heat sink layer. The thermal resistance layer can be etched to reduce roughness.

[0049] In some aspects, a seed layer 308 / 408 is provided as a seed layer for the MRL 310 / 410 to provide a thermal barrier and aid nucleation, thereby permitting proper crystal growth within the MRL 310 / 410 so that the MRL 310 / 410 will have a good crystallographic texture with small grains. The seed layer 308 / 408 may be made of MgOTiO (MTO) or possibly MgO. In one aspect, the seed layer may be implemented using multiple layers (e.g., multiple MTO layers or a combination of MgO layers and MTO layers).

[0050] In some aspects, the MRL 310 / 410 includes one or more magnetic recording layers ( Figure 3 and Figure 4 The MRL 310 / 410 may include a magnetic recording sublayer and an exchange control sublayer (ECL). These sublayers together form the MRL structure 310 / 410, which may be, for example, 100 angstroms. to In some aspects, the MRL 310 / 410 may be made of FePt. In some aspects, the MRL 316 may be made of an alloy selected from FePtY, wherein Y is a material selected from Cu, Ni, and combinations thereof. In other aspects, the MRL 310 / 410 may be made of a CoPt alloy instead. In some aspects, the MRL 310 / 410 may be formed of a high anisotropy L10 FePt and a separator (such as C, BN, SiO2, Ag, TiO2, and / or a combination thereof). In some aspects, the MRL is a four-layer MRL. Each layer of the MRL may have a separator, wherein the amount of the separator varies between layers within the MRL.

[0051] In some aspects, the capping layer 312 / 412 may be made of one or more magnetic materials (e.g., Co, Fe, Pt, or Pd) and one or more separators (e.g., B, BN, TiO2, SiO2, C, or AlN).

[0052] In one aspect, the sacrificial layer 314 / 414 is made of C (e.g., non-hydrogenated carbon, as distinguished from hydrogenated carbon, such as DLC or carbon films deposited by CVD or sputtered C). In one aspect, the sacrificial layer 314 / 414 is made of at least one of C, SiO2, Al2O3, ZrO2, or TiO2. At a kinetic energy of about 600 electron volts (eV), these materials can have an etch / sputter rate (in angstroms or s) of 20, 70, 40, 40, 40, respectively. For reference, the etching / sputtering rate of FePt is between 180 and 200 within the range.

[0053] In one aspect, the protective layer 316 / 416 is made of amorphous hydrogenated carbon such as DLC or non-hydrogenated tetrahedral amorphous carbon (ta-C). Either hydrogenated carbon or non-hydrogenated carbon can be used as the material for the sacrificial layer. However, in each case, during the etching process (such as Figures 5a to 5i The remaining sacrificial carbon film properties after etching become significantly different from the original film initially deposited (as shown in block 564 of the process of ). In one aspect, for example, a sacrificial layer having about 70% sp2 bonded atoms is deposited, which increases to about 95% after etching.

[0054] In some aspects, the lubricant layer can be made of a polymer-based lubricant material.

[0055] It is noted that as used herein, the terms "over", "under", "on", and "between" refer to the relative position of one layer with respect to other layers. Thus, a layer deposited or disposed on, over, or under another layer may be in direct contact with the other layer, or may have one or more intervening layers. Additionally, a layer deposited or disposed between layers may be in direct contact with the layers, or may have one or more intervening layers.

[0056] With regard to the processes described herein, these processes may in some cases perform a sequence of actions in different orders. On the other hand, the process may skip one or more actions in the action. In other respects, one or more actions in the action are performed simultaneously. In some respects, additional actions may be performed. Unless otherwise specified, various deposition processes or sub-processes may be used to perform the deposition of at least some of these layers, including but not limited to physical vapor deposition (PVD), sputtering deposition and ion beam deposition, plasma enhanced chemical vapor deposition (PECVD) and other forms of chemical vapor deposition (CVD), low pressure chemical vapor deposition (LPCVD) and atomic layer chemical vapor deposition (ALCVD). In other respects, other suitable deposition techniques known in the art may also be used.

[0057] Figures 5a to 5i A series of cross-sectional views of a magnetic media workpiece 500 and corresponding actions performed on the magnetic media workpiece 500 in a process for reducing the surface roughness of magnetic media using selective etching of sacrificial and capping layers are shown in accordance with aspects of the present disclosure.

[0058] exist Figure 5a In the process, the process first provides (550) a substrate 502. The substrate 502 can be implemented with any of the substrates 302 / 402 described above.

[0059] exist Figure 5b In the process, the process provides (552) a cushion layer 504 on the substrate 502. The cushion layer 504 can be made of any of the materials described above for the cushion layer 304 / 404. In one aspect, the process deposits the cushion layer 504 using any of the deposition techniques described above.

[0060] exist Figure 5c , the process provides (554) a heat sink layer 506 on the cushion layer 504. The heat sink layer 506 can be made of any of the materials described above for the heat sink layer 306 / 406. In one aspect, the process deposits the heat sink layer 506 using any of the deposition techniques described above.

[0061] exist Figure 5d , the process provides (556) a seed layer 508 on the heat sink layer 506. The seed layer 508 can be made of any of the materials described above for the seed layer 308 / 408. In one aspect, the process deposits the seed layer 508 using any of the deposition techniques described above.

[0062] exist Figure 5eIn the process, a magnetic recording layer (MRL) 510 is provided (558) on the seed layer 508. The MRL 510 may be made of any of the materials described above for the MRL 310 / 410, and may be formed of a plurality of layers described above. In one aspect, the process deposits the MRL 510 using any of the deposition techniques described above. In some aspects, the MRL material includes a material that forms recording grains 510a and a material that acts as separators 510b between recording grains (e.g., where the separators divide and define the recording grains at so-called "grain boundaries"). Materials suitable for recording grains 510a (e.g., FePt) and separators 510b (e.g., C, BN, SiO2, AlN, Ag, TiO2) are described above. In one aspect, the separators are made of BN.

[0063] exist Figure 5f , the process provides (560) a capping layer 512 on the MRL 510. The capping layer 512 may include a grain material (e.g., a capping grain 512a made of material formed on or attached to an existing MRL grain 510a) and one or more separators (e.g., a capping separator 512b formed on an existing MRL separator 510a). The capping layer 512 may be made of any of the materials described above for the capping layer 312 / 412, including, for example, CoFe for the capping grain and B for the capping separator. In one aspect, the process deposits the capping layer 512 using any of the deposition techniques described above.

[0064] exist Figure 5g , the process provides (562) a sacrificial layer 514 on the capping layer 512. The sacrificial layer 514 can be made of any of the materials described above for the sacrificial layer 314 / 414, including, for example, one or more of the following: non-hydrogenated C, SiO2, Al2O3, ZrO2, or TiO2. In one aspect, the process deposits the sacrificial layer 514 using any of the deposition techniques described above.

[0065] exist Figure 5hIn one aspect, the process etches (564) the sacrificial layer 514 and portions of the capping layer 514. In one aspect, the process performs the etching (564) using a plasma enhanced etch with an inert gas (such as one or more of Kr, Ar, or Xe). In one aspect, portions of the sacrificial layer 514 remain at the grain boundaries after etching (564), such that the sacrificial layer 514 becomes discontinuous with segments remaining at the grain boundaries. The capping layer 512, and in particular the top portions of the capping grains 512a, are effectively planarized by the etching process. In one aspect, the etching process is carefully adjusted and by using a sacrificial layer (for selective etching) to ensure planarization of the capping grains 512a without etching (or otherwise damaging) the recording grains 510a. In one aspect, etching (564) involves etching the capping grains 512a but not etching the capping boundaries (512b). In one aspect, etching the sacrificial layer and the portion of the capping layer includes etching the sacrificial layer and the portion of the capping layer such that the remaining portion of the sacrificial layer 514 is substantially positioned at the capping boundary. In one aspect, the remaining portion of the sacrificial layer 514 is intermixed (chemically and / or physically) with the capping separator 512b at the grain / capping boundary (e.g., C of the sacrificial layer 514 is intermixed with B or BN of the capping separator 512b).

[0066] In one aspect, etching (564) involves etching the sacrificial layer until the sacrificial layer becomes discontinuous and includes a plurality of segments each positioned at a capping boundary, such as, for example Figure 5h , Figure 5i and Figure 4 shown.

[0067] In one aspect, etching (564) involves etching the sacrificial layer and portions of the capping layer, but does not include etching the MRL.

[0068] In one aspect, etching (564) involves etching the sacrificial layer and is carried out at a rate of less than 100 s per second. The etching rate of the capping layer is performed.

[0069] In one aspect, etching (564) the sacrificial layer and a portion of the capping layer results in planarization of the portion of the capping layer and a remaining portion of the sacrificial layer, such as, for example Figure 5h , Figure 5i and Figure 4 shown.

[0070] exist Figure 5i, the process provides (566) a protective layer 516 on the capping layer 512 and the sacrificial layer 514, and then provides (566) a lubricant layer 518 on the protective layer 516. The protective layer 516 can be made of any of the materials described above for the protective layer 316 / 416, including, for example, DLC. The lubricant layer 518 can be made of any of the materials described above for the lubricant layer 318 / 418, including, for example, a polymer-based lubricant. In one aspect, the process uses any of the deposition techniques described above to deposit the protective layer 516 and / or the lubricant layer 518. In one aspect, Figure 5i HAMR medium and Figure 4 The medium is essentially the same.

[0071] In one aspect, the protective layer is made of diamond-like carbon (DLC) and the sacrificial layer is made of C having different properties than DLC (eg, DLC is formed of hydrogenated carbon while the sacrificial layer carbon is not hydrogenated).

[0072] As described above, HAMR media such as media 500 or media 300 / 400 may also have additional intermediate layers (eg, such as adhesion layers, heat sink seed layers, thermal resistance layers, etc.).

[0073] In one aspect, Figures 5a to 5i The process shown may be used to manufacture any of the HAMR media described above, including, for example, HAMR media 102 , 300 , 400 , and 500 .

[0074] It is noted that as used herein, the terms "over", "under", "on", and "between" refer to the relative position of one layer with respect to other layers. Thus, a layer deposited or disposed on, over, or under another layer may be in direct contact with the other layer, or may have one or more intervening layers. Additionally, a layer deposited or disposed between layers may be in direct contact with the layers, or may have one or more intervening layers.

[0075] With regard to the processes described herein, these processes may in some cases perform a sequence of actions in different orders. On the other hand, the process may skip one or more actions in the action. In other respects, one or more actions in the action are performed simultaneously. In some respects, additional actions may be performed. Unless otherwise specified, various deposition processes or sub-processes may be used to perform the deposition (or provision) of at least some of these layers, including but not limited to physical vapor deposition (PVD), sputtering deposition and ion beam deposition, plasma enhanced chemical vapor deposition (PECVD) and other forms of chemical vapor deposition (CVD), low pressure chemical vapor deposition (LPCVD) and atomic layer chemical vapor deposition (ALCVD). In other respects, other suitable deposition techniques known in the art may also be used.

[0076] Figure 6 6 is a flow chart of an exemplary process 600 for manufacturing a HAMR medium including a sacrificial layer and a capping layer, wherein the process etches both the sacrificial layer and the capping layer to reduce roughness, according to aspects of the present disclosure. In one aspect, process 600 can be used to manufacture any of the HAMR media described above, including, for example, HAMR media 102, 300, 400, and 500.

[0077] At block 602, the process provides a substrate (e.g., 302, 402, 502). At block 604, the process provides a heat sink layer (e.g., 306, 406, 506) on the substrate. In one aspect, the process may additionally provide a soft magnetic underlayer (SUL, e.g., 304, 404, 504) on the substrate and provide the heat sink layer on the SUL. At block 606, the process provides a magnetic recording layer (MRL, e.g., 310, 410, 510) on the heat sink layer. In one aspect, the process may additionally provide a seed layer (e.g., 308, 408, 508) on the heat sink layer, and then provide the MRL on the seed layer. At block 608, the process provides a capping layer (e.g., 312, 412, 512) on the MRL.

[0078] At box 610, the process provides a sacrificial layer (e.g., 314, 414, 514) on the capping layer. At box 612, the process etches the sacrificial layer (e.g., 314, 414, 514) and the capping layer (e.g., 312, 412, 512). In one aspect, the process etches the capping grains (412a, 512a) but does not etch the capping separators (412b, 512b). In one aspect, the process etches the sacrificial layer until it becomes discontinuous and includes a plurality of segments, each of which is positioned at a grain boundary (e.g., at a position corresponding to the capping separator). At box 614, the process provides a protective layer (e.g., 316, 416, 516) on the etched sacrificial layer and the etched portion of the capping layer. In one aspect, the protective layer is made of DLC or another suitable protective layer material. At optional block 616 , the process provides a lubricant layer (eg, 318 , 418 , 518 ) on the protective layer.

[0079] In one aspect, process 600 may include Figures 5a to 5i Any of the actions shown in the illustrated process or described above for the process.

[0080] It is noted that as used herein, the terms "over", "under", "on", and "between" refer to the relative position of one layer with respect to other layers. Thus, a layer deposited or disposed on, over, or under another layer may be in direct contact with the other layer, or may have one or more intervening layers. Additionally, a layer deposited or disposed between layers may be in direct contact with the layers, or may have one or more intervening layers.

[0081] With regard to the processes described herein, these processes may in some cases perform a sequence of actions in different orders. On the other hand, the process may skip one or more actions in the action. In other respects, one or more actions in the action are performed simultaneously. In some respects, additional actions may be performed. Unless otherwise specified, various deposition processes or sub-processes may be used to perform the deposition (or provision) of at least some of these layers, including but not limited to physical vapor deposition (PVD), sputtering deposition and ion beam deposition, plasma enhanced chemical vapor deposition (PECVD) and other forms of chemical vapor deposition (CVD), low pressure chemical vapor deposition (LPCVD) and atomic layer chemical vapor deposition (ALCVD). In other respects, other suitable deposition techniques known in the art may also be used.

[0082] Figure 7 7 is a graph 700 showing exemplary average roughness 702 and coercivity values ​​704 for a first test medium 706 without a sacrificial layer and without an etch, a second test medium 708 with an etch of a capping layer but without a sacrificial layer, and a third test medium 710 with an etch of both a sacrificial layer and a capping layer, according to aspects of the present disclosure. Figure 7 As can be seen from the figure, the average surface roughness (in angstroms or The third test medium 710 has a coercive force (measured in kilo (K) Oersteds (Oe)) lower than the average roughness of each of the first test medium 706 and the second test medium 708 despite the use of selective etching. In addition, despite the use of selective etching, the coercive force (measured in kilo (K) Oersteds (Oe)) of the third test medium 710 remains as high as the coercive force provided by the first test medium 706. On the other hand, the coercive force of the second test medium 708 including the etching of the capping layer is reduced compared to the first or third test media. Such a reduction in coercive force may result in a reduction in recording performance.

[0083] Figure 8 is a graph 800 showing exemplary X-ray diffraction characterization data according to aspects of the present disclosure, including Figure 7The (002) peak intensity 802 of the magnetic grains of the same three test media (706, 708, 710) is shown in Figure 1. The Y-axis shows the peak intensity 802 of the magnetic grains measured in counts per second (CPS). The X-axis shows the 2-θ angle 804 measured in degrees. The 2-θ angle is the angle between the direction of the incident ray beam and the direction of the diffracted X-ray beam, and it is characteristic of the crystal orientation of certain phases. Figure 8 As can be seen in the first test medium 706 without etching and the third test medium 710 including the sacrificial layer and the selective etching exhibit high magnetic grain peak intensity (e.g., for magnetic grains formed of FePt having a (002) crystal orientation). However, the data of the second test medium 708 including etching the capping layer without the sacrificial layer shows a significant reduction in the grain peak intensity. This reduction in peak intensity may lead to a reduction in recording performance.

[0084] Now consider Figure 7 and Figure 8 The data for both, unexpectedly, will show that for the third test media 710 with selective etching, both the coercivity and the magnetic grain peak intensity will remain as high as in the unetched test media (e.g., the first test media 706), especially in view of the data for the second test media 708 (with capping layer etching), which showed a significant reduction in both of these beneficial media properties. In other words, the HAMR media with selective etching described herein provide precision etching that results in a reduction in media surface roughness while maintaining important magnetic recording properties, including high grain coercivity and high grain peak intensity. Although a reduction in media surface roughness may be expected, maintaining relatively high grain coercivity and high grain peak intensity is not expected given that prior test media etches the capping layer without a sacrificial layer and shows reduced levels of these performance characteristics.

[0085] Fig. 9900 is a graph showing read signal-to-noise ratio (SNR) gain 902 versus protective layer deposition time 904 for a first test medium 906 without an etch of a sacrificial layer and a capping layer, a second test medium 910 with an etch of a sacrificial layer and a capping layer, and an etch of both a sacrificial layer and a capping layer, according to aspects of the present disclosure. In one aspect, the first test medium 906 may be associated with a magnetic medium manufactured using the techniques disclosed in U.S. Pat. No. 8,900,465, which may involve etching of a thick carbon layer and then depositing a protective layer on the remaining carbon. The read signal-to-noise ratio gain 902 is measured in decibels (dB). The protective layer deposition time 904 is measured in seconds (s). The data in graph 900 shows that for a protective layer deposition time of about 1.8 seconds, the read SNR gain of the second test medium 910 (etch with sacrificial layer) is about 1 dB higher than the read SNR gain of the first test medium 906 (etch without sacrificial layer and capping layer), and up to 1.8 dB higher for a protective layer deposition time of about 3 seconds. Thus, the read SNR improvement for the second test medium 910 is in the range of 1 dB to 1.8 dB. While this amount may not seem high in the abstract, it results in substantially higher recording performance. The resulting increase in read SNR is unexpected for the same reasons as above.

[0086] Fig.10 1000 is a graph showing slip 1002 versus protective layer thickness 1004 for a first test medium 1006 without an etched sacrificial layer and a capping layer and a second test medium 1010 with an etched sacrificial layer and a capping layer and both according to aspects of the present disclosure. In one aspect, the first test medium 1006 may be associated with a magnetic medium manufactured using the techniques disclosed in U.S. Pat. No. 8,900,465, which may involve etching of a thick carbon layer and then depositing a protective layer on the remaining carbon. In a slip test, a magnetic head flying at a fixed flying height above the disk is used to scan the media surface of the disk for asperity defects. If any defect-driven thermal asperity is detected, the disk may be rejected. The slip 1002 is measured as a percentage and is the ratio of the number of asperity-free disks to the total number of test disks, thereby representing the defect level detected when the head slides on the rotating media, where a higher percentage slip is expected to indicate fewer defects measured at the media surface. The protective layer thickness 1004 is normalized.

[0087] The data in Figure 1000 shows that the first test medium 1006 (without etching of the sacrificial layer and the capping layer) requires a minimum protective layer thickness of about 2.3 times the normalized thickness to obtain a slip rate of 85% (or higher), and has relatively poor / low slip rates in the range of 1.7 times to 2.1 times the normalized protective layer thickness. In contrast, the second test medium 1010 (with selective etching of a portion of the sacrificial layer and the capping layer) achieves a slip rate of over 85% with a protective layer thickness as small as 1.0 normalized thickness or anywhere between 1.1 times and 1.7 times the normalized thickness. Therefore, Fig.10 It is shown that HAMR media with selective etching allows for substantially thinner protective layers (eg, 50% thinner or more). Thus, the head-to-media spacing can be reduced, and magnetic recording performance can be improved. In one aspect, the target slip ratio can be 85% or higher.

[0088] Additional aspects

[0089] The examples set forth herein are provided to illustrate certain concepts of the present disclosure. The devices, equipment or components shown above may be configured to perform one or more of the methods, features or steps described herein. It will be appreciated by those of ordinary skill in the art that these are merely exemplary in nature, and other examples may fall within the scope of the present disclosure and the appended claims. Based on the teachings herein, it will be appreciated by those skilled in the art that the aspects disclosed herein may be implemented independently of any other aspects, and two or more of these aspects may be combined in various ways. For example, any number of aspects set forth herein may be used to implement a device or a method may be practiced. In addition, in addition to or in place of one or more aspects set forth herein, other structures, functions, or structures and functions may be used to implement such a device or such a method may be practiced.

[0090] Various aspects of the present disclosure have been described below with reference to schematic flow charts and / or schematic block diagrams of methods, devices, systems, and computer program products according to aspects of the present disclosure. It should be understood that each frame of the schematic flow chart and / or schematic block diagram, and the combination of frames in the schematic flow chart and / or schematic block diagram can be implemented by computer program instructions. These computer program instructions can be provided to a processor or other programmable data processing device of a computer to produce a machine, so that instructions executed by the processor or other programmable data processing device create a device for implementing the functions and / or actions specified in one or more frames of the schematic flow chart and / or schematic block diagram.

[0091] The subject matter described herein may be implemented in hardware, software, firmware, or any combination thereof. Thus, the terms "function", "module", etc., used herein, may refer to hardware, which may also include software and / or firmware components, for implementing the described features. In an exemplary implementation, the subject matter described herein may be implemented using a computer-readable medium having computer-executable instructions stored thereon, which control the computer to perform the functions described herein when executed by a computer (e.g., a processor). Examples of computer-readable media suitable for implementing the subject matter described herein include non-transitory computer-readable media, such as disk memory devices, chip memory devices, programmable logic devices, and application-specific integrated circuits. In addition, the computer-readable medium implementing the subject matter described herein may be located on a single device or computing platform, or may be distributed across multiple devices or computing platforms.

[0092] It should also be noted that in some alternative implementations, the functions shown in the frame may not occur in the order shown in the figure. For example, in fact, the two frames shown in succession may be performed substantially simultaneously, or these frames may sometimes be performed in the opposite order, depending on the functions involved. Other steps and methods that are equivalent to one or more frames or parts thereof of the drawings shown in function, logic or effect can be envisioned. Although various arrow types and line types can be used in flow charts and / or block diagrams, it should be understood that these arrow types and line types do not limit the scope of the corresponding aspects. For example, an arrow can indicate a waiting or monitoring period of unspecified duration between the enumerated steps of the depicted aspect.

[0093] The various features and processes described above can be used independently of each other, or can be combined in various ways. All possible combinations and sub-combinations are intended to fall within the scope of the present disclosure. In addition, certain methods, events, states or process blocks can be omitted in some specific implementations. The methods and processes described herein are also not limited to any specific sequence, and the blocks or states associated therewith can be performed in other appropriate sequences. For example, the tasks or events described can be performed in a sequence different from that specifically disclosed, or multiple can be combined in a single block or state. Exemplary tasks or events can be performed in series, in parallel or in some other suitable manner. Tasks or events can be added to or removed from the disclosed exemplary aspects. The exemplary systems and components described herein can be configured differently from those described. For example, compared to the disclosed exemplary aspects, elements can be added, removed or rearranged.

[0094] Those skilled in the art will appreciate that any of a variety of different techniques and technologies may be used to represent information and signals. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the above specification may be represented by voltage, current, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0095] 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 "aspect" does not require that all aspects include the discussed feature, advantage, or mode of operation. The term "coupled" is used herein to refer to a direct or indirect coupling between two objects. For example, if object A physically touches object B, and object B touches object C, then object A and object C may still be considered coupled to each other (even if they are not directly physically touching each other). It is also noted that in the context of one component being above another component, the term "above..." as used in this application may be used to refer to a component that is on and / or in (e.g., on a surface of or embedded in) another component. Thus, for example, a first component that is above a second component may mean that (1) the first component is on the second component but not directly contacting the second component, (2) the first component is on (e.g., on a surface of) the second component, and / or (3) the first component is in (e.g., embedded in) the second component. As used in this disclosure, the term "about 'value X'" or "approximately value X" shall mean within 10% of "value X". For example, a value of about 1 or approximately 1 would mean a value in the range of 0.9–1.1. In one aspect, "about" as used herein may alternatively mean 5%. In this disclosure, various ranges of values ​​may be specified, described, and / or claimed. It should be noted that any time a range is specified, described, and / or claimed in the specification and / or claims, it is meant to include the end value (at least in one embodiment). In another embodiment, the range may not include the end value of the range.

[0096] Although the above description includes many specific aspects of the present invention, these should not be interpreted as limiting the scope of the invention, but as examples of its specific aspects. Therefore, the scope of the present invention should not be determined by the aspects shown, but should be determined by the attached claims and their equivalents. In addition, "an aspect", "aspect" or similar language mentioned throughout this specification refers to the specific features, structures or characteristics described in conjunction with this aspect being included in at least one aspect of the present disclosure. Therefore, the phrases "in one aspect (in one aspect)", "in an aspect (in an aspect)" and similar language that appear throughout this specification may but not necessarily all refer to the same aspect, but refer to "one or more but not all aspects", unless otherwise clearly stated.

[0097] The terms used herein are only for the purpose of describing a specific embodiment, and are not intended to limit the embodiment. As used herein, the singular form "a / an" and "the" are also intended to include plural forms (i.e., one or more), unless the context clearly indicates otherwise. The enumerated list of items does not mean that any or all items in the project are mutually exclusive and / or mutually inclusive, unless otherwise clearly stated. It should also be understood that, unless otherwise clearly stated, the terms "comprising", "including", "including", "including", "having" and their variations used herein mean "including but not limited to". That is, these terms can specify the existence of stated features, integers, steps, operations, elements or parts, but do not exclude the existence or addition of one or more other features, integers, steps, operations, elements, parts or their groups. In addition, it should be understood that the word "or" has the same meaning as the Boolean operator "OR", that is, it includes the possibility of "or" and "both", and is not limited to "exclusive or" ("XOR"), unless otherwise clearly stated. It should also be understood that the symbol " / " between two adjacent words has the same meaning as "or", unless otherwise clearly stated. Furthermore, phrases such as "connected to," "coupled to," or "in communication with," are not limited to direct connections unless expressly stated otherwise.

[0098] Various components described in this specification may be described as "comprising" or being made of certain materials or combinations of materials. In one aspect, this may mean that the component is composed of one or more specific materials. In another aspect, this may mean that the component includes one or more specific materials.

[0099] Any reference to an element using names such as "first", "second" etc. herein does not generally limit the quantity or order of those elements. On the contrary, these designations can be used as a convenient method to distinguish two or more elements or element instances in this article. Therefore, the reference to the first and second elements does not mean that only two elements can be used there, or that the first element must be before the second element in some way. In addition, unless otherwise specified, a group of elements may include one or more elements. In addition, the term "at least one of a, b or c" or "a, b, c or any combination thereof" used in the specification or claims refers to "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.

[0100] As used herein, the term "determining" encompasses various actions. For example, "determining" may include arithmetic, calculation, processing, derivation, investigation, lookup (e.g., lookup in a table, database, or another data structure), ascertainment, etc. Also, "determining" may include receiving (e.g., receiving information), accessing (e.g., accessing data in a memory), etc. Also, "determining" may include parsing, selecting, choosing, establishing, etc.

Claims

1. A magnetic recording medium, comprising: substrate; A heat sink layer, the heat sink layer is located on the substrate; a magnetic recording layer (MRL), the magnetic recording layer (MRL) being located on the heat sink layer, the MRL comprising a plurality of recording grains, the plurality of recording grains being separated by separators at grain boundaries of the plurality of recording grains; a capping layer located on the MRL and including magnetic material at positions corresponding to the plurality of recording grains and capping separators at positions corresponding to the grain boundaries; and A sacrificial layer is embedded in the capping layer at a location corresponding to the grain boundary, the sacrificial layer comprising a non-magnetic material different from the capping particles, wherein a top surface of the capping layer and a top surface of the sacrificial layer are substantially coplanar.

2. The magnetic recording medium according to claim 1, further comprising: a protective layer, the protective layer being located on the capping layer; and A lubricant layer is located on the protective layer.

3. The magnetic recording medium according to claim 2: wherein the protective layer comprises amorphous carbon having a first percentage of sp2-bonded atoms; and Wherein the sacrificial layer comprises C having a second percentage of sp2 bonded atoms greater than the first percentage of sp2 bonded atoms.

4. The magnetic recording medium of claim 1, wherein the sacrificial layer comprises at least one of the following: C, SiO2, Al2O3, ZrO2, or TiO2.

5. The magnetic recording medium according to claim 1: wherein each of the sacrificial layer and the capping layer comprises a remnant of an inert gas used in an etching process; and The inert gas comprises at least one of the following: Kr, Ar or Xe. The magnetic recording medium according to claim 1 , wherein a thickness of the sacrificial layer is smaller than a thickness of the capping layer.

7. The magnetic recording medium of claim 1, wherein the top surface of the capping layer and the top surface of the sacrificial layer are substantially flat. 8 . The magnetic recording medium of claim 7 , wherein the top surface of the capping layer and the top surface of the sacrificial layer are substantially flat due to a flattening process applied thereto.

9. A magnetic recording medium, comprising: substrate; A heat sink layer, the heat sink layer is located on the substrate; a magnetic recording layer (MRL), the magnetic recording layer (MRL) being located on the heat sink layer, the MRL comprising a plurality of recording grains, the plurality of recording grains being separated by separators at grain boundaries of the plurality of recording grains; a capping layer located on the MRL and including a magnetic material disposed on each of the plurality of recording grains and another material disposed at the grain boundaries; a discontinuous sacrificial layer, the discontinuous sacrificial layer comprising a plurality of segments, each of the plurality of segments being located on the capping layer at a position corresponding to the grain boundary, the sacrificial layer comprising a material different from that of the capping layer; a protective layer, the protective layer being located on the capping layer; and A lubricant layer is located on the protective layer.

10. The magnetic recording medium according to claim 9: wherein a top surface of the capping layer and a top surface of the sacrificial layer are substantially flat; and Wherein the top surface of the capping layer and the top surface of the sacrificial layer are substantially coplanar. 11 . The magnetic recording medium of claim 10 , wherein the top surface of the capping layer and the top surface of the sacrificial layer are substantially flat due to a flattening process applied thereto.

12. The magnetic recording medium according to claim 9: wherein the protective layer comprises amorphous carbon having a first percentage of sp2-bonded atoms; and Wherein the sacrificial layer comprises C having a second percentage of sp2 bonded atoms greater than the first percentage of sp2 bonded atoms.

13. The magnetic recording medium of claim 9, wherein the sacrificial layer comprises at least one of: C, SiO2, Al2O3, ZrO2, or TiO2.

14. A method for manufacturing a magnetic recording medium, the method comprising: providing a substrate; providing a heat sink layer on the substrate; providing a magnetic recording layer (MRL) on the heat sink layer; providing a capping layer on the MRL, the capping layer comprising a magnetic material; providing a sacrificial layer on the capping layer, the sacrificial layer comprising a material different from the magnetic material of the capping layer; etching the sacrificial layer and portions of the capping layer; as well as A protective layer is provided on the etched sacrificial layer and the etched portion of the capping layer.

15. The method according to claim 14: wherein the MRL comprises a plurality of recording grains, the plurality of recording grains being separated by separators at grain boundaries of the plurality of recording grains; wherein the capping layer comprises capping grains and capping boundaries disposed between the capping grains, the capping grains being located at positions corresponding to the plurality of recording grains; and Wherein etching the sacrificial layer and the portion of the capping layer includes etching the capping grains but not etching the capping boundaries. 16 . The method of claim 15 , wherein etching the sacrificial layer and the portion of the capping layer comprises etching the sacrificial layer and the portion of the capping layer such that a remaining portion of the sacrificial layer is substantially positioned at the capping boundary.

17. The method according to claim 14: wherein the MRL comprises a plurality of recording grains, the plurality of recording grains being separated by separators at grain boundaries of the plurality of recording grains; wherein the capping layer comprises capping grains and capping boundaries disposed between the capping grains, the capping grains being located at positions corresponding to the plurality of recording grains; and Wherein etching the sacrificial layer and the portion of the capping layer comprises etching the sacrificial layer until the sacrificial layer becomes discontinuous and comprises a plurality of segments, each of the plurality of segments being positioned at the capping boundary.

18. The method of claim 14, wherein etching the sacrificial layer and the portion of the capping layer does not include etching the MRL.

19. The method of claim 14, wherein etching the sacrificial layer and the portion of the capping layer is performed at an etch rate of less than 10 angstroms per second.

20. The method of claim 14, wherein etching the sacrificial layer and the portion of the capping layer results in planarization of the portion of the capping layer and a remaining portion of the sacrificial layer.

21. The method according to claim 14, further comprising: providing a lubricant layer on the protective layer; wherein the protective layer comprises amorphous carbon having a first percentage of sp2-bonded atoms; and Wherein the sacrificial layer comprises C having a second percentage of sp2 bonded atoms greater than the first percentage of sp2 bonded atoms.

22. The method of claim 14, wherein the sacrificial layer comprises at least one of: C, SiO2, Al2O3, ZrO2, or TiO2.

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