Method for manufacturing magnetic recording medium and magnetic recording / reproducing device

Abstract

The purpose of the present invention is to provide: a method for manufacturing a magnetic recording medium, which can improve the vertical orientation of a magnetic recording layer and can further increase the recording density; and a magnetic recording / reproducing device provided with a magnetic recording medium manufactured by the manufacturing method. The method for manufacturing a magnetic recording medium according to the present invention is a method for manufacturing a magnetic recording medium provided with an underlayer, a seed layer, and a magnetic recording layer in this order on a non-magnetic substrate, the seed layer being formed by forming a film containing two elements, i.e., an element [alpha] and an element [beta], the element [alpha] being mainly a columnar crystal having an fcc structure, and the element [beta] being mainly a columnar crystal having an fcc structure. After the film is formed such that the element [beta] mainly has an amorphous structure, the surface of the film is etched to form a surface in which the element [alpha] and the element [beta] are separated from each other.

Description

Technical Field

[0001] This invention relates to a method for manufacturing a magnetic recording medium and a magnetic recording regeneration apparatus. Background Technology

[0002] In hard disk drives (HDDs), a type of magnetic recording playback device, magnetic recording media suitable for high recording densities have been developed. Currently commercially available magnetic recording playback devices use so-called perpendicular magnetic recording media, where the easy magnetization axis within a magnetic film is vertically oriented. With perpendicular magnetic recording media, the influence of demagnetizing magnetic fields in the boundary regions between storage bits is minimal at high recording densities, resulting in distinct bit boundaries and suppressing subsequent noise increases. Furthermore, the reduction in storage bit volume associated with high recording density in perpendicular magnetic recording media is minimal, thus exhibiting excellent thermal fluctuation characteristics.

[0003] As such a perpendicular magnetic recording medium, for example, Patent Document 1 discloses a perpendicular magnetic recording medium having the following layers stacked in sequence: a non-magnetic orientation control layer having at least one of the group consisting of silver, palladium and ruthenium as the main component; a non-magnetic seed layer having silver particles that maintain the fcc structure and germanium grain boundaries that are amorphous; a non-magnetic intermediate layer formed of a ruthenium alloy; and a perpendicular magnetic recording layer formed of cobalt or iron and platinum.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2013-196752 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] The demand for higher recording density in magnetic recording media has never ceased, and the required characteristics of magnetic recording media are to be improved beyond those of the past. Specifically, in order to increase the recording density of magnetic recording media, the magnetic particles that make up the magnetic recording layer need to be made finer than before, and the vertical orientation of the magnetic particles needs to be improved.

[0009] The present invention was made in view of the prior art and aims to provide a method for manufacturing a magnetic recording medium that improves the vertical orientation of the magnetic recording layer and further achieves a high recording density, and a magnetic recording regeneration apparatus having a magnetic recording medium manufactured by the method.

[0010] Methods for solving problems

[0011] The present invention provides the following methods.

[0012] [1] A method for manufacturing a magnetic recording medium, comprising a method for manufacturing a magnetic recording medium having a substrate layer, a seed layer and a magnetic recording layer sequentially disposed on a non-magnetic substrate.

[0013] The seed layer is formed by making a film containing two elements, α and β, in which α mainly forms columnar crystals with an fcc structure and β mainly forms an amorphous structure. Then, the surface of the film is etched to form a surface in which α and β are separated from each other.

[0014] [2] According to the manufacturing method of magnetic recording medium described in [1], after forming a surface in which the above-mentioned element α and the above-mentioned element β are separated from each other, an alloy mainly containing the above-mentioned element α is further formed on the surface.

[0015] [3] Argon gas is used in the above etching process according to the manufacturing method of the magnetic recording medium described in [1] or [2].

[0016] [4] In the method for manufacturing a magnetic recording medium according to any one of [1] to [3], the substrate layer is formed from the non-magnetic substrate side in a manner that includes a first substrate layer, a second substrate layer, and a third substrate layer.

[0017] The aforementioned first base layer mainly comprises any one of Ru, Cr, and Ni.

[0018] The second basal layer mentioned above mainly contains element α.

[0019] The aforementioned third basal layer mainly contains any one of Ru, Cr, and Mo.

[0020] [5] The method for manufacturing a magnetic recording medium according to any one of [1] to [4], wherein the element α is any one of Ag, Au, Al and Pd.

[0021] The element β mentioned above is either Ge or Si.

[0022] [6] According to the method for manufacturing a magnetic recording medium according to any one of [1] to [5], an intermediate layer is formed between the seed layer and the magnetic recording layer.

[0023] The aforementioned intermediate layer is primarily composed of Ru.

[0024] The aforementioned magnetic recording layer is a layer mainly composed of Co, Cr, and Pt.

[0025] [7] According to the method for manufacturing a magnetic recording medium according to any one of [1] to [6], an intermediate layer is formed between the seed layer and the magnetic recording layer.

[0026] The aforementioned intermediate layer mainly contains NaCl-type compounds.

[0027] The aforementioned magnetic recording layer mainly contains magnetic particles with an L10 structure.

[0028] [8] A magnetic recording and reproducing apparatus having a magnetic recording medium,

[0029] The aforementioned magnetic recording medium comprises, sequentially, a substrate layer, a seed layer, and a magnetic recording layer on a non-magnetic substrate.

[0030] The seed layer is formed by making a film containing two elements, α and β, in which α mainly forms columnar crystals with an fcc structure and β mainly forms an amorphous structure. Then, the surface of the film is etched to form a surface in which α and β are separated from each other.

[0031] The effects of the invention

[0032] This invention can improve the vertical orientation of the magnetic recording layer, thereby achieving a higher recording density. Attached Figure Description

[0033] Figure 1 This is a cross-sectional view showing an example of the structure of a magnetic recording medium manufactured by the manufacturing method of the magnetic recording medium according to an embodiment of the present invention.

[0034] Figure 2 This is a perspective view showing an example of a magnetic recording reproduction apparatus that uses a magnetic recording medium manufactured by the manufacturing method of the magnetic recording medium according to an embodiment of the present invention. Detailed Implementation

[0035] Hereinafter, a method for manufacturing a magnetic recording medium and a magnetic recording reproduction apparatus according to embodiments of the present invention will be described in detail with reference to the accompanying drawings. Furthermore, the accompanying drawings used in the following description may sometimes be enlarged representations of parts of features for ease of understanding and convenience; the dimensions and ratios of the constituent elements may not be identical to the actual dimensions. In this specification, the tilde “~” indicating a numerical range means that, unless otherwise specified, the values ​​described before and after it include both the lower and upper limits. Moreover, when only the unit of the upper limit value is described in the numerical range indicated by “~”, the lower limit value is also in the same unit.

[0036] The method for manufacturing a magnetic recording medium according to this embodiment involves sequentially comprising a substrate layer, a seed layer, and a magnetic recording layer on a non-magnetic substrate. The seed layer is formed by fabricating a film containing two elements, α and β, where element α primarily forms a columnar crystal with an fcc structure and element β primarily forms an amorphous structure. The surface of this film is then etched to create a surface where elements α and β are separated from each other. According to the method for manufacturing a magnetic recording medium according to this embodiment, the vertical orientation of the magnetic recording layer can be improved, enabling further increases in recording density.

[0037] When describing the manufacturing method of the magnetic recording medium according to this embodiment, the magnetic recording medium manufactured by the manufacturing method of the magnetic recording medium according to this embodiment will be described.

[0038] [Magnetic recording media]

[0039] Figure 1 This is a cross-sectional view showing an example of the structure of a magnetic recording medium manufactured by the manufacturing method of the magnetic recording medium according to this embodiment. Figure 1 As shown, the magnetic recording medium 1 of this embodiment has a soft magnetic liner layer 20, a base layer 30, a seed layer 40, an intermediate layer 50, a magnetic recording layer 60, a protective layer 70 and a lubricating layer 80, which are sequentially stacked on both sides of the non-magnetic substrate 10.

[0040] The magnetic recording medium 1 is formed by sequentially stacking a base layer 30, a seed layer 40 and a magnetic recording layer 60 on a non-magnetic substrate 10.

[0041] The base layer 30 has the effect of improving the crystal orientation of the seed layer 40 formed thereon. Specifically, when the columnar crystal of element α contained in the seed layer 40 has an fcc structure, the base layer 30 has the effect of improving the orientation of the (111) plane or the orientation of the (200) plane.

[0042] Preferably, the substrate 30, starting from the non-magnetic substrate 10 side, includes a first substrate 31, a second substrate 32, and a third substrate 33. The first substrate 31 mainly contains any one of Ru, Cr, and Ni, the second substrate 32 mainly contains element α, and the third substrate 33 mainly contains any one of Ru, Cr, and Mo.

[0043] By using such a structure, the magnetic recording medium 1 can miniaturize the crystalline particles constituting the seed layer 40, thereby improving the orientation of the crystalline particles. This allows for the formation of fine, highly oriented columnar crystals from the intermediate layer 50 to the magnetic recording layer 60, starting from the seed layer 40. By promoting the miniaturization and magnetic isolation of the magnetic particles contained in the magnetic recording layer 60, the magnetic recording medium 1 can improve the vertical orientation of the magnetic recording layer 60, further increasing the recording density. Therefore, the magnetic recording medium 1 significantly improves the signal-to-noise ratio (S / N ratio) during playback while also improving thermal fluctuation characteristics, thereby achieving even better recording characteristics (OW).

[0044] The first base layer 31 is a layer mainly containing any one of Ru, Cr and Ni, and serves as the starting point for crystal orientation. When the columnar crystal of element α contained in the seed layer 40 has an fcc structure, the first base layer 31 can improve the orientation of the (111) plane or the orientation of the (200) plane.

[0045] In addition, if any one of Ru, Cr and Ni is the most abundant element among the elements constituting the first base layer 31, the content of any one of Ru, Cr and Ni is preferably 50 atomic% or more of the elements constituting the first base layer 31, and 100 atomic% of the elements constituting the first base layer 31.

[0046] The thickness of the first substrate layer 31 is preferably in the range of 1 to 10 nm.

[0047] The second base layer 32 is a layer that mainly contains element α of the seed layer 40. By forming the same crystal orientation as the seed layer 40, the orientation of the (111) plane or the orientation of the (200) plane can be improved when the columnar crystal of element α contained in the seed layer 40 is an fcc structure.

[0048] In addition, if the main component element α is the most abundant element among the elements constituting the second base layer 32, the content of the main component element α is preferably 50 atomic% or more of the elements constituting the second base layer 32, and 100 atomic% of the elements constituting the second base layer 32.

[0049] The thickness of the second substrate layer 32 is preferably in the range of 1 to 10 nm.

[0050] The third substrate layer 33 is a layer mainly containing any one of Ru, Cr, and Mo, and is preferentially alloyed with element β at the interface with the seed layer 40. Thus, while promoting phase separation of element α and element β, and in the case where the columnar crystals of element α contained in the seed layer 40 have an fcc structure, the third substrate layer 33 can improve the orientation of the (111) plane or the (200) plane. Furthermore, the third substrate layer 33 has the effect of suppressing the diffusion of unwanted elements from the non-magnetic substrate 10 side to the seed layer 40.

[0051] In addition, if any one of Ru, Cr and Mo is the most abundant element among the elements constituting the third base layer 33, the preferred content of any one of Ru, Cr and Mo is 50 atomic% or more of the elements constituting the third base layer 33, and 100 atomic% of the elements constituting the third base layer 33.

[0052] The thickness of the third substrate layer 33 is preferably in the range of 1 to 10 nm.

[0053] Seed layer 40 contains two elements that are phase-separated from each other. The phase of element α mainly has columnar crystals with an fcc structure, while the phase of element β mainly has an amorphous structure.

[0054] The seed layer 40 is preferably formed using a eutectic alloy in which element α and element β phases are separated. In the case of such a eutectic alloy, the phase of element α readily forms fine crystals with uniform grain size, and the phase of element β surrounds the crystals of element α, thereby readily forming a uniform granular structure.

[0055] Preferably, element α of the seed layer 40 is any one of Ag (with an fcc structure), Au (with an fcc structure), Al (with an fcc structure), and Pd (with an fcc structure), and element β is any one of Ge and Si. By using elements α and β, the alloy constituting the seed layer 40 becomes a eutectic alloy, the phase of element α becomes columnar crystals with a uniformly sized, fine fcc structure, and the phase of element β becomes an amorphous structure. Therefore, the seed layer 40 readily becomes a granular structure containing columnar crystals of element α and an amorphous structure of element β surrounding the columnar crystals of element α. As the alloy constituting the seed layer 40, AgGe, AgSi, AlGe, AuGe, and AlSi are particularly preferred, for example.

[0056] The thickness of the seed layer 40 is such that the above structure can be maintained, and it is preferably as thin as possible, for example, preferably less than 100 nm.

[0057] The magnetic recording layer 60 may use a Co-Cr-Pt alloy as the main component and further include oxides. As oxides, oxides of any of Cr, Si, Ta, Al, Ti, Mg, Co, and B are preferred. Among these, TiO2, Cr2O3, SiO2, and B2O3 are particularly suitable. Furthermore, the magnetic recording layer 60 preferably contains composite oxides with two or more oxides added. Among these, Cr2O3-SiO2, Cr2O3-TiO2, and Cr2O3-SiO2-TiO2 are particularly suitable.

[0058] The thickness of the magnetic recording layer 60 is preferably 5 to 20 nm. If the thickness of the magnetic recording layer 60 is 5 nm or more, sufficient reproduction output is obtained, and the reduction of thermal fluctuation characteristics is suppressed. Furthermore, if the thickness of the magnetic recording layer 60 is 20 nm or less, the hypertrophy of magnetic particles in the magnetic recording layer 60 is suppressed, the increase of noise during recording reproduction is suppressed, and the deterioration of recording reproduction characteristics represented by the S / N ratio and recording characteristics (OW) is suppressed, which is therefore preferred.

[0059] The magnetic recording layer 60 can be a multilayer structure, and non-magnetic layers can be added between the multilayer magnetic recording layers 60. As the non-magnetic layer disposed between the magnetic recording layers 60, a material with an hcp structure is preferably used. For example, Ru, Ru alloys, CoCr alloys, and CoCrX1 alloys (X1 represents at least one or more elements selected from Pt, Ta, Zr, Re, Ru, Cu, Nb, Ni, Mn, Ge, Si, O, N, W, Mo, Ti, V, Zr, and B) are suitable.

[0060] Furthermore, by adding a grain boundary segregation material to the magnetic recording layer 60, the magnetic recording layer 60 can be made into a granular structure. This improves the orientation of the (001) plane of the magnetic recording layer 60. Examples of grain boundary segregation materials include nitrides such as VN, BN, SiN, and TiN; carbides such as C and VC; and borides such as BN. Two or more of these materials can be used in combination.

[0061] The magnetic recording medium 1 includes an intermediate layer 50 between the seed layer 40 and the magnetic recording layer 60. The intermediate layer 50 is a layer mainly containing Ru or MgO, and the magnetic recording layer 60 is preferably a layer mainly containing a Co-Cr-Pt alloy containing Co, Cr and Pt.

[0062] In addition, Ru or MgO is the most abundant element among the elements constituting the intermediate layer 50, preferably Ru or MgO content, which includes more than 50 atomic percent of the elements constituting the intermediate layer 50, and 100% of the elements constituting the intermediate layer 50.

[0063] If an intermediate layer 50, mainly comprising Ru or MgO, is formed on the seed layer 40, the crystalline particles constituting the intermediate layer 50 correspond to the crystalline particles of the seed layer 40 in a 1:1 ratio, and simultaneously grow epitaxially as continuous columnar crystals in the thickness direction. Furthermore, if a magnetic recording layer 60 is formed on the intermediate layer 50, the crystalline particles constituting the magnetic recording layer 60 correspond to the crystalline particles of the intermediate layer 50 in a 1:1 ratio, and simultaneously grow epitaxially as continuous columnar crystals in the thickness direction.

[0064] In particular, if the crystal particles of element α constituting the seed layer 40 are any of Ag, Au, Al and Pd with an fcc structure oriented (111) or (200), the intermediate layer 50 is Ru or MgO with an hcp structure oriented (200), and the magnetic recording layer 60 is a Co-Cr-Pt alloy with an hcp structure oriented (002), the epitaxially grown columnar crystals become more uniform.

[0065] In addition, the intermediate layer 50 preferably mainly contains NaCl-type compounds, and the magnetic recording layer 60 mainly contains magnetic particles with an L10 structure.

[0066] In addition, the element constituting the intermediate layer 50 is mainly composed of NaCl-type compounds, and the content of NaCl-type compounds is preferably more than 50 atomic percent of the elements constituting the intermediate layer 50, and 100% of the elements constituting the intermediate layer 50.

[0067] Furthermore, the magnetic particles that mainly contain L10 structures are the most abundant magnetic particles constituting the magnetic recording layer 60. The content of magnetic particles containing L10 structures is preferably 50 atomic percent or more of the magnetic particles constituting the magnetic recording layer 60, and 100% of the magnetic particles constituting the magnetic recording layer 60.

[0068] Examples of magnetic particles with an L10 structure include, for example, FePt alloy particles and CoPt alloy particles. Furthermore, examples of NaCl-type compounds include, for example, MgO, TiO, NiO, TiN, TaN, HfN, NbN, ZrC, HfC, TaC, NbC, and TiC. These can be used individually or in combination of two or more.

[0069] If an intermediate layer 50, primarily comprising a NaCl-type compound, is formed on the seed layer 40, the crystalline particles constituting the intermediate layer 50 correspond to the crystalline particles of the seed layer 40 in a 1:1 ratio, and thus grow epitaxially as continuous columnar crystals in the thickness direction. Furthermore, if a magnetic recording layer 60 is formed on the intermediate layer 50, the crystalline particles constituting the magnetic recording layer 60 correspond to the crystalline particles of the intermediate layer 50 in a 1:1 ratio, and thus grow epitaxially as continuous columnar crystals in the thickness direction.

[0070] In particular, the first substrate layer 31 of the substrate layer 30 is mainly composed of Ni with an (111) orientation in the fcc structure, the crystal particles of element α constituting the seed layer 40 are any one of Ag, Au, Al, and Pd with an (111) orientation in the fcc structure, the intermediate layer 50 is Ru with a (200) orientation, and the magnetic recording layer 60 is FePt alloy with a (001) orientation in the L10 structure, thereby making the epitaxially grown columnar crystals more uniform. Furthermore, the first substrate layer 31 of the substrate layer 30 is Cr with a (200) orientation in the fcc structure, the crystal particles of element α constituting the seed layer 40 are any one of Ag, Au, Al, and Pd with a (200) orientation in the fcc structure, the intermediate layer 50 is MgO with a (200) orientation of a NaCl-type compound, and the magnetic recording layer 60 is FePt alloy with a (001) orientation in the L10 structure, thereby making the epitaxially grown columnar crystals more uniform. Among these, Ag is particularly preferred as element α.

[0071] One or more elements selected from the group consisting of Al, Si, Ga, and Ge can be added to the magnetic particles having the L10 structure. The amount of these elements added is preferably 2 to 20 mol%, more preferably 2.5 to 10 mol%. If these elements are added in the amounts described above, the orientation of the (001) plane of the magnetic recording layer 60 is improved.

[0072] Explain the other components.

[0073] As the non-magnetic substrate 10, for example, a metal substrate containing metallic materials such as aluminum and aluminum alloys can be used, or a non-metallic substrate containing non-metallic materials such as glass, ceramics, silicon, silicon carbide, and carbon can be used. Furthermore, substrates on which a NiP layer or a NiP alloy layer is formed, for example, using a plating method or sputtering method, can be used.

[0074] The soft magnetic liner layer 20 is configured to increase the vertical component of the magnetic flux generated from the magnetic head relative to the substrate surface of the non-magnetic substrate 10, while more firmly fixing the magnetization direction of the magnetic recording layer 60 on which information is recorded to the direction perpendicular to the non-magnetic substrate 10. Its effect becomes particularly significant when a single magnetic pole head for perpendicular recording is used as the magnetic head for recording and playback.

[0075] As the soft magnetic liner layer 20, for example, a soft magnetic material having an amorphous or microcrystalline structure containing Fe, Ni, or Co can be used. Examples of soft magnetic materials include, for example, CoFe alloys (such as CoFeTaZr and CoFeZrNb), FeCo alloys (such as FeCo and FeCoV), FeNi alloys (such as FeNi, FeNiMo, FeNiCr, and FeNiSi), FeAl alloys (such as FeAl, FeAlSi, FeAlSiCr, FeAlSiTiRu, and FeAlO), FeCr alloys (such as FeCr, FeCrTi, and FeCrCu), FeTa alloys (such as FeTa, FeTaC, and FeTaN), FeMg alloys (such as FeMgO), FeZr alloys (such as FeZrN), FeC alloys, FeN alloys, FeSi alloys, FeP alloys, FeNb alloys, FeHf alloys, and FeB alloys.

[0076] The soft magnetic liner layer 20 is preferably composed of two soft magnetic films, with a Ru film disposed between the two soft magnetic films. By adjusting the thickness of the Ru film within the range of 0.4–1.0 nm or 1.6–2.6 nm, the two soft magnetic films form an AFC structure. By having such an AFC structure, the soft magnetic liner layer 20 is able to suppress so-called spike noise.

[0077] The protective layer 70 inhibits corrosion of the magnetic recording layer 60 while also preventing damage to the surface of the magnetic recording medium 1 when the magnetic head comes into contact with it. The protective layer 70 can be made of materials commonly used as protective layers, for example, materials containing carbon. Examples of protective layers 70 include, for instance, hard carbon films.

[0078] The thickness of the protective layer 70 is preferably 1 to 10 nm from the perspective of reducing the distance between the head and the magnetic recording medium 1 and achieving a high recording density of the magnetic recording medium 1. If the thickness of the protective layer 70 is 1 nm or more, the corrosion resistance of the magnetic recording layer 60 becomes good; if it is less than 10 nm, the magnetic spacing becomes smaller, and the SNR (signal-to-noise ratio) of the magnetic recording medium 1 can be improved.

[0079] The lubricating layer 80 can be formed using a liquid lubricant layer. Suitable liquid lubricants are chemically stable, low-friction, and have low adsorption properties. For example, perfluoropolyether-based lubricants containing compounds having a perfluoropolyether structure, fluorinated alcohols, and fluorinated carboxylic acids are preferred.

[0080] The thickness of the lubricating layer 80 is not particularly limited; for example, it can be 1 to 3 nm.

[0081] Furthermore, in addition to the protective layer 70 and the lubricating layer 80, the magnetic recording medium 1 may appropriately include any other layers. For example, the magnetic recording medium 1 may, as needed, include an adhesive layer, a soft magnetic substrate layer, an alignment control layer, etc., between any of the non-magnetic substrate 10, the base layer 30, and the magnetic recording layer 60. The soft magnetic substrate layer may, for example, be composed of a first soft magnetic layer, an intermediate layer, and a second soft magnetic layer. The alignment control layer may be one layer or two layers (e.g., a first alignment control layer, a second alignment control layer, etc.) or more. The materials used to form the adhesive layer, the soft magnetic substrate layer, the alignment control layer, etc., can be general materials used in magnetic recording media.

[0082] [Manufacturing methods for magnetic recording media]

[0083] This embodiment describes a method for manufacturing a magnetic recording medium. Furthermore, in this embodiment, as an example of a method for manufacturing a magnetic recording medium, the manufacture of magnetic recording medium 1 will be described.

[0084] The method for manufacturing a magnetic recording medium according to this embodiment is a method for manufacturing a magnetic recording medium 1 on a non-magnetic substrate 10, wherein a base layer 30, a seed layer 40 and a magnetic recording layer 60 are sequentially provided. The seed layer 40 is formed by forming a film containing two elements, element α and element β, such that element α mainly forms columnar crystals with an fcc structure and element β mainly forms an amorphous structure. After forming the film, the surface of the film is etched to form a surface in which element α and element β are separated from each other.

[0085] In the method for manufacturing a magnetic recording medium according to this embodiment, a soft magnetic liner layer 20 is formed on both sides of a non-magnetic substrate 10 using a sputtering method or the like.

[0086] Next, a base layer 30 is formed on the surface of the soft magnetic liner layer 20 that is different from the non-magnetic substrate 10.

[0087] The substrate 30 is formed by sequentially stacking a first substrate 31, a second substrate 32, and a third substrate 33 from the non-magnetic substrate 10 side. The method for forming each of the first substrate 31, the second substrate 32, and the third substrate 33 is not particularly limited, and a general thin film formation method can be used, such as sputtering.

[0088] Next, a seed layer 40 is formed on the side of the substrate 30 that is different from the soft magnetic liner layer 20. The method for forming the seed layer 40 is not particularly limited, and general thin film formation methods can be used, such as sputtering.

[0089] In this embodiment, the seed layer 40 is formed by making a film containing two elements, α and β, such that α mainly forms columnar crystals with an fcc structure and β mainly forms an amorphous structure. After forming the film, its surface is etched to form a surface in which α and β are separated from each other.

[0090] In this embodiment, the seed layer 40 has the effect of epitaxial growth of continuous columnar crystals as the crystal particles of the layer formed thereon corresponding to the crystal particles of the seed layer 40 in a 1:1 ratio. On the surface of the seed layer 40, which serves as the starting point of its epitaxial growth, the phase separation of element α and element β becomes clear, thereby making the epitaxially grown columnar crystals more uniform.

[0091] In this embodiment, after forming a surface where elements α and β are separated from each other, an alloy whose surface mainly comprises element α is further formed. An alloy mainly comprising element α means that element α is the most abundant element among the constituent elements of the alloy; preferably, element α accounts for 50% or more, including cases where all constituent elements of the alloy are element α. This reduces defects on the crystalline surface of element α, further reduces element β on the surface covered by element α, and makes the crystalline surface of element α hemispherical, thus facilitating the epitaxial growth of the layer formed on it as continuous columnar crystals in the thickness direction, with a 1:1 correspondence between the crystalline particles of the layer formed and the crystalline particles of element α.

[0092] In this embodiment, the etching of the film containing two elements, α and β, is preferably performed using dry etching with an inert gas. Examples of inert gases include argon, helium, xenon, neon, krypton, and nitrogen, with argon being particularly preferred. By using argon, the phase separation of element α and element β on the surface of the seed layer 40 can be performed more clearly.

[0093] Next, an intermediate layer 50 is formed on the side of the seed layer 40 that is different from the base layer 30. The method for forming the intermediate layer 50 is not particularly limited, and general thin film formation methods can be used, such as sputtering.

[0094] Next, a magnetic recording layer 60 is formed on the side of the intermediate layer 50 that is different from the seed layer 40. The method for forming the magnetic recording layer 60 is not particularly limited; general thin film formation methods can be used, such as sputtering.

[0095] Next, a protective layer 70 is formed on the side of the magnetic recording layer 60 that is different from the intermediate layer 50.

[0096] Methods for forming a protective layer include, for example, RF-CVD (Radio Frequency-Chemical Vapor Deposition), which decomposes hydrocarbon gas (raw material gas) using high-frequency plasma to form a film; IBD (Ion Beam Deposition), which uses electrons emitted from the beam to ionize the raw material gas to form a film; and FCVA (Filtered Cathodic Vacuum Arc), which forms a film using a solid carbon target without using a raw material gas.

[0097] Next, a lubricating layer 80 is formed on the surface of the protective layer 70 that is different from the magnetic recording layer 60 using a conventional coating method, such as a coating process. Thus, a lubricating layer 80 is obtained. Figure 1 The magnetic recording medium 1 shown.

[0098] Thus, the method for manufacturing the magnetic recording medium according to this embodiment forms a seed layer 40 by forming a film containing two elements, α and β, where element α mainly forms columnar crystals with an fcc structure and element β mainly forms an amorphous structure. After forming the film, its surface is etched to form a surface where element α and element β are separated from each other. On the surface of the seed layer 40, by making the phase separation of element α and element β clear, the seed layer 40, for example, can continuously epitaxially grow the crystal particles of layers formed on the seed layer 40, such as the intermediate layer 50 and the magnetic recording layer 60, in the thickness direction, thereby enabling the formation of more uniform columnar crystals on the seed layer 40. Therefore, the method for manufacturing the magnetic recording medium according to this embodiment can improve the vertical orientation of the magnetic recording layer 60, making further high recording density possible.

[0099] In the method for manufacturing a magnetic recording medium according to this embodiment, it is preferable that, after forming a surface where elements α and β are separated from each other during the formation of the seed layer 40, an alloy mainly comprising element α is further formed on its surface. For example, the seed layer 40 is facilitated by allowing the crystalline particles of the layers formed on the seed layer 40, such as the intermediate layer 50 and the magnetic recording layer 60, to continuously epitaxially grow in the thickness direction, thereby facilitating the further formation of uniform columnar crystals on the seed layer 40. Therefore, the method for manufacturing a magnetic recording medium according to this embodiment can further improve the vertical orientation of the magnetic recording layer 60 and further increase the recording density.

[0100] In the method for manufacturing a magnetic recording medium according to this embodiment, when forming the seed layer 40, argon gas is preferably used for etching the film containing two elements, α and β. By using argon gas, the phase separation of element α and element β on the surface of the seed layer 40 can be performed more clearly. Therefore, for example, by facilitating the continuous epitaxial growth of crystalline particles of the layers formed on the seed layer 40, such as the intermediate layer 50 and the magnetic recording layer 60, in the thickness direction, it is easier to further form uniform columnar crystals on the seed layer 40. As a result, the method for manufacturing a magnetic recording medium according to this embodiment can further improve the vertical orientation of the magnetic recording layer 60 and further improve the recording density.

[0101] In the method for manufacturing a magnetic recording medium according to this embodiment, it is preferable that the substrate layer 30 is formed from the non-magnetic substrate 10 side, comprising a first substrate layer 31, a second substrate layer 32, and a third substrate layer 33, wherein the first substrate layer 31 mainly comprises any one of Ru, Cr, and Ni, the second substrate layer 32 mainly comprises element α, and the third substrate layer 33 mainly comprises any one of Ru, Cr, and Mo. Therefore, when the columnar crystals of element α contained in the seed layer 40 have an fcc structure, the orientation of the (111) plane or the (200) plane can be improved, while the unexpected diffusion of elements into the seed layer 40 can be suppressed. Therefore, columnar crystals that improve the orientation of the (111) plane or the (200) plane of the layers formed on the seed layer 40, such as the intermediate layer 50 and the magnetic recording layer 60, can be easily formed on the seed layer 40. Therefore, the method for manufacturing a magnetic recording medium according to this embodiment can further improve the vertical orientation of the magnetic recording layer 60 and further improve the recording density.

[0102] In the method for manufacturing the magnetic recording medium according to this embodiment, element α is preferably any one of Ag, Au, Al and Pd, and element β is any one of Ge and Si.

[0103] Therefore, for example, the crystal particles of the layers formed on the seed layer 40, such as the intermediate layer 50 and the magnetic recording layer 60, can be epitaxially grown continuously and more uniformly in the thickness direction, thereby enabling the formation of uniform columnar crystals on the seed layer 40. Thus, the method for manufacturing the magnetic recording medium according to this embodiment can further improve the vertical orientation of the magnetic recording layer 60 and further increase the recording density.

[0104] In the method for manufacturing a magnetic recording medium according to this embodiment, the intermediate layer 50 is preferably a layer mainly containing Ru, and the magnetic recording layer 60 is a layer mainly containing Co, Cr, and Pt. This allows the crystal particles of the magnetic recording layer 60 formed on the intermediate layer 50 to grow continuously and more uniformly in the thickness direction, thereby enabling the magnetic recording layer 60 to be formed with more uniform columnar crystals. Therefore, the method for manufacturing a magnetic recording medium according to this embodiment can further improve the vertical orientation of the magnetic recording layer 60 and further increase the recording density.

[0105] In the method for manufacturing a magnetic recording medium according to this embodiment, the intermediate layer 50 preferably mainly comprises a NaCl-type compound, and the magnetic recording layer 60 is a layer mainly comprising magnetic particles having an L10 structure. Therefore, by enabling the crystalline particles of the magnetic recording layer 60 formed on the intermediate layer 50 to grow continuously and more uniformly in the thickness direction, the magnetic recording layer 60 can be further formed with uniform columnar crystals. Thus, the method for manufacturing a magnetic recording medium according to this embodiment can further improve the vertical orientation of the magnetic recording layer 60 and further increase the recording density.

[0106] The method for manufacturing a magnetic recording medium according to this embodiment can produce a magnetic recording medium 1 having the characteristics described above. Therefore, even when using heat-assisted recording or microwave-assisted recording as the recording method of the obtained magnetic recording medium 1, the magnetic recording layer 60 has a high recording density, thereby enabling sufficient recording of magnetic information on the magnetic recording layer 60 by the recording magnetic field of the magnetic head. Therefore, the magnetic recording medium 1 obtained by the method for manufacturing a magnetic recording medium according to this embodiment is suitable for use in a magnetic recording playback apparatus with even higher recording density.

[0107] [Magnetic Recording Reproduction Device]

[0108] This describes a magnetic recording playback apparatus (also called a "magnetic recording device") that incorporates the magnetic recording medium described in this embodiment. The magnetic recording playback apparatus described in this embodiment is not particularly limited in form as long as it incorporates the magnetic recording medium described in this embodiment.

[0109] Figure 2 This is a perspective view showing an example of a magnetic recording and reproducing apparatus using the magnetic recording medium described in this embodiment. Figure 2 As shown, the magnetic recording playback apparatus 100 includes: a perpendicular magnetic recording medium 101, a medium driving unit 102 for rotating the perpendicular magnetic recording medium 101, a magnetic head 103 for recording playback information for the perpendicular magnetic recording medium 101, a head driving unit 104 for moving the magnetic head 103 relative to the perpendicular magnetic recording medium 101, and a recording playback signal processing system 105. The perpendicular magnetic recording medium 101 uses the above-described... Figure 1The magnetic recording medium 1 is shown. In addition, the recording and playback signal processing system 105 can process data input from the outside and transmit the recording signal to the magnetic head 103, and process the playback signal from the magnetic head 103 and transmit the data to the outside.

[0110] In the magnetic recording playback apparatus 100, the magnetic recording medium 1 is further able to have excellent recording characteristics (OW), so the magnetic recording playback apparatus 100 can have excellent high-density recording.

[0111] As described above, embodiments have been illustrated, but these embodiments are merely examples and do not limit the invention. The embodiments described above can be implemented in various other ways, and various combinations, omissions, substitutions, modifications, etc., can be made without departing from the spirit of the invention. These embodiments and their variations are included within the scope and spirit of the invention, and are included within the scope of the invention as described in the claims and its equivalents.

[0112] Example

[0113] The following examples illustrate this implementation in more detail, but this implementation is not limited to these examples.

[0114] <Example 1>

[0115] (Manufacturing method of magnetic recording medium)

[0116] In Example 1, a cleaned glass substrate (manufactured by HOYA, 3.5 inches in diameter) was placed in the chamber of a film deposition apparatus (manufactured by Anelva, C-3010) as a non-magnetic substrate. The film deposition chamber was depressurized and evacuated until a vacuum of 1×10⁻⁶ was reached. -5 Pa. Then, on the glass substrate, using a Cr target, a 10 nm thick bonding layer was formed by DC magnetron sputtering. On this bonding layer, with the substrate temperature below 100 °C, using a Co-20Fe-5Zr-5Ta target {Fe content 20 atomic%, Zr content 5 atomic%, Ta content 5 atomic%, remainder Co}, a 25 nm thick soft magnetic liner layer was formed by DC magnetron sputtering. On the soft magnetic liner layer, a 0.7 nm thick Ru layer was formed by DC magnetron sputtering, and then again using a Co-20Fe-5Zr-5Ta target, a 25 nm thick soft magnetic liner layer was formed by DC magnetron sputtering.

[0117] Next, on the soft magnetic liner layer, using an 82Ni-3W-15Fe target (W content 3 atomic%, Fe content 15%, remaining Ni) and DC magnetron sputtering, a first substrate layer with a thickness of 5 nm was formed.

[0118] Next, on the first substrate layer, an Ag target is used to form a second substrate layer with a thickness of 2 nm by DC magnetron sputtering.

[0119] Next, using a Ru target, a third substrate layer with a thickness of 0.3 nm was formed on the second substrate layer by DC magnetron sputtering.

[0120] Next, a seed layer is formed on the third substrate layer. Using a 40Ag-60Ge target and α-Ag, a 5nm thick film is deposited via RF sputtering. The surface is then dry-etched using argon gas. The dry etching process uses an argon gas pressure of 7Pa as the substrate bias, employing a pulsed bias of 200V, 250kHz, and 1616ns. The etching time is 7 seconds. Then, using an Ag target and a DC magnetron sputtering method, a 1nm thick film is formed, thus creating the seed layer.

[0121] Next, using a Ru target, an intermediate layer with a thickness of 20 nm was formed. Additionally, during the formation of the intermediate layer, the sputtering pressure was set to 0.8 Pa, and after forming a Ru film with a thickness of 10 nm, the sputtering pressure was set to 1.5 Pa, and another Ru film with a thickness of 10 nm was formed.

[0122] Next, a three-layer magnetic recording layer was formed on the intermediate layer using DC magnetron sputtering. Specifically, a first magnetic recording layer with a thickness of 9 nm was formed using a target of 91(Co15Cr16Pt)-6(SiO2)-3(TiO2) {Cr content 15 atomic%, Pt content 16 atomic%, the remaining Co alloy is 91 mol%, SiO2 oxide is 6 mol%, and TiO2 oxide is 3 mol%}. The sputtering pressure at this time was 2 Pa.

[0123] Next, on the first magnetic recording layer, a second magnetic recording layer with a thickness of 6 nm was formed using a target of 92(Co11Cr18Pt)-5(SiO2)-3(TiO2) {Cr content 11 atomic%, Pt content 18 atomic%, the remaining Co alloy is 92 mol%, SiO2 oxide is 5 mol%, TiO2 oxide is 3 mol%}. Additionally, the sputtering pressure at this time was 2 Pa.

[0124] Next, on the second magnetic recording layer, a third magnetic recording layer with a thickness of 7 nm was formed using a target of Co20Cr14Pt3B {Cr content 20 atomic%, Pt content 14 atomic%, B content 3 atomic%, and the remainder Co}. The sputtering pressure at this time was 0.6 Pa.

[0125] Next, on the third magnetic recording layer, a protective layer with a thickness of 3 nm was formed by CVD, and then a lubricating film containing perfluoropolyether with a thickness of 1 nm was formed by impregnation, thereby obtaining the magnetic recording medium of Example 1. The composition of each layer of the fabricated magnetic recording medium is shown in Tables 1 to 3.

[0126] The fabricated magnetic recording medium was observed using a transmission electron microscope (JEM-ARM200F NEOARM, manufactured by Nippon Electron Ltd., accelerating voltage: 200kV). The average particle size D of the magnetic particles constituting the first to third magnetic recording layers was measured, as well as the particle size dispersion σ / D, which was normalized using this average particle size D. Furthermore, the c-axis orientation dispersion (Δθ50) of the intermediate layer was evaluated by X-ray diffraction. Δθ50 was measured using the diffraction peaks of the (002) plane, even when the intermediate layer consisted of either Ru or MgO. The evaluation results are shown in Tables 2 and 3. In addition, the smaller the values ​​of the average particle size D, particle size dispersion σ / D, and c-axis orientation dispersion Δθ50, the finer the magnetic particles are, resulting in higher orientation.

[0127] The manufacturing conditions of the magnetic particles in the magnetic recording medium, including the first to third base layers, seed layer, intermediate layer, and magnetic recording layer, are shown in Tables 1 to 3.

[0128] (Magnetic properties of magnetic recording media)

[0129] The magnetic properties (coercivity Hc, saturation magnetic field strength Hs) of the magnetic recording medium were measured using a magneto-optical Kerr effect measurement device. The measurement results are shown in Table 3.

[0130] <Examples 2-13, Comparative Examples 1-8>

[0131] The magnetic recording medium was fabricated in the same manner as in Example 1, but the fabrication conditions for the first to third substrate layers, seed layers, intermediate layers, and magnetic recording layers were changed as shown in Tables 1 to 3. Examples 1 to 8 are comparative examples where argon etching and element α film formation were not performed during seed layer formation. Examples 9 to 13 are examples where the conditions for argon etching and element α film formation in Example 1 were changed. Additionally, in Example 6, the substrate temperature was 250°C during the formation of the MgO-containing intermediate layer, and the substrate temperature was 450°C during the formation of the FePt-containing magnetic recording layer. The evaluation results are shown in Tables 2 and 3.

[0132] [Table 1]

[0133]

[0134] [Table 2]

[0135]

[0136] [Table 3]

[0137]

[0138] As shown in Tables 2 and 3, compared with the comparative examples manufactured using magnetic particles with the same composition of magnetic recording layer, the magnetic recording media of each embodiment showed higher values ​​for coercivity Hc and saturation magnetic field strength Hs, thus improving magnetic properties.

[0139] Therefore, by forming a seed layer on the substrate layer, a film containing two elements, α and β, is created, where element α mainly forms columnar crystals with an fcc structure and element β mainly forms an amorphous structure. After the film is formed, its surface is etched to create a surface where element α and element β are separated from each other, thus forming a seed layer. This confirms that the magnetic properties of the magnetic recording layer of the manufactured magnetic recording medium are improved. Therefore, the magnetic recording medium obtained by the manufacturing method of the magnetic recording medium according to the various embodiments has a magnetic recording layer with high recording density, thereby enabling the magnetic storage device to have a high recording capacity when used in a magnetic storage device.

[0140] Explanation of symbols

[0141] 1. Magnetic recording media

[0142] 10 Non-magnetic substrates

[0143] 20 Soft magnetic lining layer

[0144] 30 Basal layer

[0145] 31 First basal layer

[0146] 32 Second basal layer

[0147] 33 Third basal layer

[0148] 40 seed layers

[0149] 50 Intermediate Layer

[0150] 60 magnetic recording layers

[0151] 70 protective layers

[0152] 80 Lubricating layer

[0153] 100 Magnetic Recording Reproduction Device

[0154] 101 Perpendicular magnetic recording medium

Claims

1. A method for manufacturing a magnetic recording medium, comprising a method for manufacturing a magnetic recording medium having a substrate layer, a seed layer, and a magnetic recording layer sequentially disposed on a non-magnetic substrate. The seed layer is formed by fabricating a film containing two elements, α and β, where α is mainly a columnar crystal with an fcc structure and β is mainly an amorphous structure. After the film is formed, the surface of the film is etched to form a surface in which α and β are separated from each other.

2. The method for manufacturing a magnetic recording medium according to claim 1, After forming a surface on which the elements α and β are separated from each other, an alloy mainly comprising the element α is further formed on this surface.

3. The method for manufacturing the magnetic recording medium according to claim 1 or 2, The etching process uses argon gas.

4. The method for manufacturing the magnetic recording medium according to claim 1 or 2, The substrate layer is formed from the non-magnetic substrate side in a manner comprising a first substrate layer, a second substrate layer, and a third substrate layer. The first base layer mainly comprises any one of Ru, Cr, and Ni. The second basal layer mainly contains element α. The third basal layer mainly comprises any one of Ru, Cr and Mo.

5. The method for manufacturing the magnetic recording medium according to claim 1 or 2, The element α is any one of Ag, Au, Al, and Pd. The element β is either Ge or Si.

6. The method for manufacturing a magnetic recording medium according to claim 1 or 2, An intermediate layer is formed between the seed layer and the magnetic recording layer. The intermediate layer is a layer that mainly contains Ru. The magnetic recording layer is a layer mainly composed of Co, Cr and Pt.

7. The method for manufacturing a magnetic recording medium according to claim 1 or 2, An intermediate layer is formed between the seed layer and the magnetic recording layer. The intermediate layer mainly contains NaCl-type compounds. The magnetic recording layer mainly contains magnetic particles with an L10 structure.

8. A magnetic recording and playback device, It has a magnetic recording medium, The magnetic recording medium comprises a substrate layer, a seed layer, and a magnetic recording layer sequentially on a non-magnetic substrate. The seed layer is formed by fabricating a film containing two elements, α and β, where α is mainly a columnar crystal with an fcc structure and β is mainly an amorphous structure. After the film is formed, the surface of the film is etched to form a surface in which α and β are separated from each other.

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