Method of manufacturing magnetic recording medium and magnetic recording and reproducing apparatus

Abstract

To provide a manufacturing method of a magnetic recording medium capable of further increasing the recording density by enhancing the perpendicular orientation of a magnetic recording layer, and to provide a magnetic recording and reproducing device equipped with the magnetic recording medium manufactured by the manufacturing method.SOLUTION: A method of manufacturing a magnetic recording medium according to the present invention is a method of manufacturing a magnetic recording medium including, on a non-magnetic substrate, an underlayer, a seed layer, and a magnetic recording layer in this order, wherein the seed layer is formed by forming a film containing two elements of an element α and an element β such that the element α mainly forms a columnar crystal having an fcc structure and the element β mainly forms an amorphous structure, and then etching a surface of the film to form a surface in which the element α and the element β are phase-separated from each other.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing a magnetic recording medium and a magnetic recording and reproducing device. [Background technology]

[0002] Development of magnetic recording media suitable for high recording densities is underway for hard disk drives (HDDs), a type of magnetic recording and reproducing device. Currently available magnetic recording and reproducing devices are equipped with so-called perpendicular magnetic recording media, in which the easy axis of magnetization in the magnetic film is oriented perpendicularly. Perpendicular magnetic recording media have a small demagnetizing field at the boundary regions between recording bits, even when recording densities are increased, resulting in clear bit boundaries and suppressing noise increases. Furthermore, perpendicular magnetic recording media have excellent thermal fluctuation characteristics because they minimize the reduction in recording bit volume associated with increased recording densities.

[0003] As such a perpendicular magnetic recording medium, for example, Patent Document 1 discloses a perpendicular magnetic recording medium that is stacked in this order: a non-magnetic orientation control layer whose main component is at least one selected from the group consisting of silver, palladium, and ruthenium; a non-magnetic seed layer having silver grains with an fcc structure and amorphous germanium grain boundaries; a non-magnetic intermediate layer formed from a ruthenium alloy; and a perpendicular magnetic recording layer formed from cobalt or iron and platinum. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-196752 Summary of the Invention [Problem to be solved by the invention]

[0005] The demand for higher recording densities in magnetic recording media continues unabated, and magnetic recording media are being required to have even better characteristics than ever before. Specifically, to increase the recording density of magnetic recording media, it is necessary to further reduce the size of the magnetic particles that make up the magnetic recording layer and improve the perpendicular orientation of the magnetic particles.

[0006] The present invention has been proposed in light of the above-mentioned conventional circumstances, and aims to provide a method for manufacturing a magnetic recording medium that improves the perpendicular orientation of the magnetic recording layer and enables even higher recording density, and a magnetic recording and reproducing device equipped with a magnetic recording medium manufactured by this manufacturing method. [Means for solving the problem]

[0007] The present invention provides the following means. [1] A method for manufacturing a magnetic recording medium having an underlayer, a seed layer, and a magnetic recording layer on a non-magnetic substrate in this order, comprising: A method for manufacturing a magnetic recording medium, wherein the seed layer is formed as a film containing two elements, element α and element β, in which the element α is formed as mainly columnar crystals with an fcc structure and the element β is formed as mainly amorphous structure, and the surface of the film is then etched to form a surface in which the element α and the element β are phase-separated from each other. [2] The method for producing a magnetic recording medium according to [1], further comprising forming a surface on which the element α and the element β are phase-separated, and then forming a film of an alloy mainly containing the element α on the surface. [3] The method for producing a magnetic recording medium according to [1] or [2], wherein argon gas is used for the etching. [4] The underlayer is formed to include, from the non-magnetic substrate side, a first underlayer, a second underlayer, and a third underlayer; the first underlayer mainly contains any one of Ru, Cr, and Ni, the second underlayer mainly contains the element α, The method for producing a magnetic recording medium according to any one of [1] to [3], wherein the third underlayer mainly contains any one of Ru, Cr, and Mo. [5] The element α is any one of Ag, Au, Al, and Pd, The method for producing a magnetic recording medium according to any one of [1] to [4], wherein the element β is either Ge or Si. [6] forming an intermediate layer between the seed layer and the magnetic recording layer; the intermediate layer is a layer mainly containing Ru, The method for producing a magnetic recording medium according to any one of [1] to [5], wherein the magnetic recording layer is a layer containing mainly Co, Cr, and Pt. [7] forming an intermediate layer between the seed layer and the magnetic recording layer; the intermediate layer primarily comprises an NaCl-type compound; The method for producing a magnetic recording medium according to any one of [1] to [6], wherein the magnetic recording layer mainly contains magnetic particles having an L10 structure. [8] A magnetic recording medium is included. the magnetic recording medium comprises an underlayer, a seed layer, and a magnetic recording layer, in this order, on a non-magnetic substrate; The seed layer is formed as a film containing two elements, element α and element β, in which the element α is formed as a columnar crystal with a fcc structure and the element β is formed as a amorphous structure, and then the surface of the film is etched to form a surface in which the element α and the element β are phase-separated from each other. [Effects of the Invention]

[0008] The present invention improves the perpendicular orientation of the magnetic recording layer, enabling even higher recording densities. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a cross-sectional view showing an example of the configuration of a magnetic recording medium manufactured by a method for manufacturing a magnetic recording medium according to an embodiment of the present invention. [Figure 2] 1 is a perspective view showing an example of a magnetic recording and reproducing device that uses a magnetic recording medium manufactured by a method for manufacturing a magnetic recording medium according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] A method for manufacturing a magnetic recording medium and a magnetic recording and reproducing device according to an embodiment of the present invention will be described in detail below with reference to the drawings. The drawings used in the following description may show characteristic portions enlarged for convenience in order to make the features easier to understand, and the dimensional ratios of each component may not necessarily be the same as in reality. In this specification, unless otherwise specified, "to" indicating a numerical range means that the numerical values ​​before and after it are included as the lower and upper limits. Furthermore, when only the upper limit value in a numerical range expressed by "to" is given in units, it also means that the lower limit value is given in the same units.

[0011] The method for manufacturing a magnetic recording medium according to this embodiment is a method for manufacturing a magnetic recording medium having an underlayer, a seed layer, and a magnetic recording layer on a non-magnetic substrate in this order, and the seed layer is formed as a film containing two elements, element α and element β, where element α is formed as a columnar crystal with a fcc structure and element β is formed as a mainly amorphous structure, and then the surface of the film is etched to form a surface where element α and element β are phase-separated from each other. The method for manufacturing a magnetic recording medium according to this embodiment can improve the perpendicular orientation of the magnetic recording layer, thereby enabling even higher recording densities.

[0012] Before describing the method for manufacturing a magnetic recording medium according to this embodiment, a magnetic recording medium manufactured by the method for manufacturing a magnetic recording medium according to this embodiment will be described.

[0013] [Magnetic recording media] 1 is a cross-sectional view showing an example of the configuration of a magnetic recording medium manufactured by the method for manufacturing a magnetic recording medium according to this embodiment. As shown in Fig. 1, the magnetic recording medium 1 according to this embodiment includes a non-magnetic substrate 10, on both sides of which a soft magnetic underlayer 20, an underlayer 30, a seed layer 40, an intermediate layer 50, a magnetic recording layer 60, a protective layer 70, and a lubricating layer 80 are sequentially stacked.

[0014] The magnetic recording medium 1 includes an underlayer 30, a seed layer 40, and a magnetic recording layer 60 stacked in this order on a non-magnetic substrate 10.

[0015] The underlayer 30 has the effect of enhancing the crystal orientation of the seed layer 40 formed thereon. Specifically, when the columnar crystals of the element α contained in the seed layer 40 have an fcc structure, the underlayer 30 has the effect of enhancing the orientation of the (111) plane or the (200) plane.

[0016] The underlayer 30 includes, from the non-magnetic substrate 10 side, a first underlayer 31, a second underlayer 32, and a third underlayer 33, and it is preferable that the first underlayer 31 mainly contains one of Ru, Cr, and Ni, the second underlayer 32 mainly contains the element α, and the third underlayer 33 mainly contains one of Ru, Cr, and Mo.

[0017] By using this structure, the magnetic recording medium 1 can reduce the size of the crystal grains constituting the seed layer 40 and improve the orientation of the crystal grains, thereby enabling the columnar crystals starting from the seed layer 40 to be formed with fine grains and high orientation from the intermediate layer 50 to the magnetic recording layer 60. By promoting the reduction in size and magnetic isolation of the magnetic grains contained in the magnetic recording layer 60, the magnetic recording medium 1 can improve the perpendicular orientation of the magnetic recording layer 60 and enable even higher recording densities. Therefore, the magnetic recording medium 1 can significantly improve the signal-to-noise ratio (S / N ratio) during reproduction and improve thermal fluctuation characteristics, thereby demonstrating even better recording characteristics (OW).

[0018] The first underlayer 31 is a layer containing primarily any one of Ru, Cr, and Ni, and is a layer that serves as a starting point for crystal orientation. When the columnar crystals of the element α contained in the seed layer 40 have an fcc structure, the first underlayer 31 can enhance the orientation of the (111) plane or the (200) plane.

[0019] Incidentally, "mainly containing one of Ru, Cr and Ni" means that when the most abundant element constituting the first underlayer 31 is one of Ru, Cr and Ni, the content of any of Ru, Cr and Ni is preferably 50 atomic % or more of the elements constituting the first underlayer 31, and includes the case where it is 100 atomic % of the elements constituting the first underlayer 31.

[0020] The thickness of the first underlayer 31 is preferably within the range of 1 to 10 nm.

[0021] The second underlayer 32 is a layer that mainly contains the element α of the seed layer 40, and by having the same crystal orientation as the seed layer 40, when the columnar crystals of the element α contained in the seed layer 40 have an fcc structure, the orientation of the (111) plane or the (200) plane can be enhanced.

[0022] In addition, "mainly containing element α" means that when the element α is the most abundant element constituting the second underlayer 32, the content of element α is preferably 50 atomic % or more of the elements constituting the second underlayer 32, and also includes the case where it is 100 atomic % of the elements constituting the second underlayer 32.

[0023] The thickness of the second underlayer 32 is preferably within the range of 1 to 10 nm.

[0024] The third underlayer 33 is a layer primarily containing any of Ru, Cr, and Mo, and is preferentially alloyed with the element β at the interface with the seed layer 40. This promotes phase separation between the element α and the element β, and when the columnar crystals of the element α contained in the seed layer 40 have an fcc structure, the third underlayer 33 can enhance the orientation of the (111) plane or the (200) plane. The third underlayer 33 also has the effect of suppressing unintended diffusion of elements from layers on the non-magnetic substrate 10 side to the seed layer 40.

[0025] In addition, "mainly containing one of Ru, Cr, and Mo" means that when the most abundant element constituting the third underlayer 33 is one of Ru, Cr, and Mo, the content of any of Ru, Cr, and Mo is preferably 50 atomic % or more of the elements constituting the third underlayer 33, and includes the case where it is 100 atomic % of the elements constituting the third underlayer 33.

[0026] The thickness of the third underlayer 33 is preferably within the range of 1 to 10 nm.

[0027] The seed layer 40 contains two elements that are phase-separated from each other, the phase of the element α having mainly columnar crystals with an fcc structure, and the phase of the element β having mainly an amorphous structure.

[0028] The seed layer 40 is preferably formed using a eutectic alloy in which the elements α and β are phase-separated. In the case of such a eutectic alloy, the phase of the element α tends to form fine crystals with a uniform grain size, and the phase of the element β tends to form a uniform granular structure by surrounding the crystals of the element α.

[0029] The element α of the seed layer 40 is preferably any one of Ag (having an fcc structure), Au (having an fcc structure), Al (having an fcc structure), and Pd (having an fcc structure), and the element β is preferably any one of Ge and Si. By using such elements for the element α and the element β, the alloy constituting the seed layer 40 becomes a eutectic alloy, the phase of the element α becomes fine columnar crystals with a uniform grain size and an fcc structure, and the phase of the element β becomes an amorphous structure. Therefore, the seed layer 40 tends to have a granular structure consisting of columnar crystals of the element α surrounded by the element β with an amorphous structure. As the alloy constituting the seed layer 40, it is particularly preferable to use, for example, AgGe, AgSi, AlGe, AuGe, or AlSi.

[0030] The thickness of the seed layer 40 is preferably as thin as possible as long as the above structure is maintained, and is preferably, for example, 100 nm or less.

[0031] The magnetic recording layer 60 is primarily composed of a Co—Cr—Pt alloy and may further contain an oxide. The oxide is preferably any of Cr, Si, Ta, Al, Ti, Mg, Co, and B. Among these, TiO2, Cr2O3, SiO2, and B2O3 are particularly suitable. The magnetic recording layer 60 is also preferably made of a composite oxide containing two or more types of oxides. Among these, Cr2O3-SiO2, Cr2O3-TiO2, and Cr2O3-SiO2-TiO2 are particularly suitable.

[0032] The thickness of the magnetic recording layer 60 is preferably 5 to 20 nm. When the thickness of the magnetic recording layer 60 is 5 nm or more, sufficient reproduction output is obtained and deterioration of thermal fluctuation characteristics is suppressed. Furthermore, when the thickness of the magnetic recording layer 60 is 20 nm or less, enlargement of the magnetic grains in the magnetic recording layer 60 is suppressed, and an increase in noise during recording and reproduction is suppressed, and deterioration of recording and reproduction characteristics, such as the S / N ratio and recording characteristics (OW), is suppressed, which is preferable.

[0033] The magnetic recording layer 60 may have a multilayer structure, or a nonmagnetic layer may be inserted between the magnetic recording layers 60 of the multilayer structure. It is preferable to use a material having an hcp structure as the nonmagnetic layer provided between the magnetic recording layers 60. For example, Ru, Ru alloy, CoCr alloy, and CoCrX1 alloy (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) can be suitably used.

[0034] Furthermore, the magnetic recording layer 60 may have a granular structure by adding a grain boundary segregation material to the magnetic recording layer 60. This improves the orientation of the (001) plane of the magnetic recording layer 60. Examples of the grain boundary segregation material include nitrides such as VN, BN, SiN, and TiN, carbides such as C and VC, and borides such as BN, and two or more of these may be used in combination.

[0035] The magnetic recording medium 1 preferably includes an intermediate layer 50 between the seed layer 40 and the magnetic recording layer 60, the intermediate layer 50 being a layer mainly containing Ru or MgO, and the magnetic recording layer 60 being a layer mainly containing a Co-Cr-Pt alloy containing Co, Cr, and Pt.

[0036] Incidentally, "mainly containing Ru or MgO" means that the most abundant element constituting the intermediate layer 50 is Ru or MgO, and the content of Ru or MgO is preferably 50 atomic % or more of the elements constituting the intermediate layer 50, and also includes the case where it accounts for 100% of the elements constituting the intermediate layer 50.

[0037] When an intermediate layer 50 containing mainly Ru or MgO is formed on the seed layer 40, the crystal grains constituting the intermediate layer 50 grow epitaxially as continuous columnar crystals in the thickness direction, while corresponding one-to-one with the crystal grains of the seed layer 40. When a magnetic recording layer 60 is formed on the intermediate layer 50, the crystal grains constituting the magnetic recording layer 60 grow epitaxially as continuous columnar crystals in the thickness direction, while corresponding one-to-one with the crystal grains of the intermediate layer 50.

[0038] In particular, if the crystal grains of element α constituting the seed layer 40 are made of Ag, Au, Al, or Pd with an fcc structure and (111) or (200) orientation, the intermediate layer 50 is made of Ru or MgO with an hcp structure and (200) orientation, and the magnetic recording layer 60 is made of a Co-Cr-Pt alloy with an hcp structure and (002) orientation, the epitaxially grown columnar crystals will be more uniform.

[0039] Preferably, the intermediate layer 50 contains primarily an NaCl-type compound, and the magnetic recording layer 60 contains primarily magnetic grains having an L10 structure.

[0040] Incidentally, "mainly containing NaCl-type compounds" means that the most abundant element constituting the intermediate layer 50 is an NaCl-type compound, and the content of the NaCl-type compound is preferably 50 atomic % or more of the elements constituting the intermediate layer 50, and also includes the case where it is 100% of the elements constituting the intermediate layer 50.

[0041] Furthermore, "mainly containing magnetic grains having an L10 structure" means that the majority of the magnetic grains constituting the magnetic recording layer 60 are magnetic grains having an L10 structure, and the content of magnetic grains having an L10 structure is preferably 50 atomic % or more of the magnetic grains constituting the magnetic recording layer 60, and also includes the case where they account for 100% of the magnetic grains constituting the magnetic recording layer 60.

[0042] Examples of magnetic particles having an L10 structure include FePt alloy particles and CoPt alloy particles. Examples of NaCl-type compounds include MgO, TiO, NiO, TiN, TaN, HfN, NbN, ZrC, HfC, TaC, NbC, and TiC. These may be used alone or in combination.

[0043] When an intermediate layer 50 containing mainly an NaCl-type compound is formed on the seed layer 40, the crystal grains constituting the intermediate layer 50 grow epitaxially as continuous columnar crystals in the thickness direction, while corresponding one-to-one with the crystal grains of the seed layer 40. When a magnetic recording layer 60 is formed on the intermediate layer 50, the crystal grains constituting the magnetic recording layer 60 grow epitaxially as continuous columnar crystals in the thickness direction, while corresponding one-to-one with the crystal grains of the intermediate layer 50.

[0044] In particular, if the first underlayer 31 of the underlayer 30 mainly contains Ni with an fcc structure and (111) orientation, the crystal grains of the element α constituting the seed layer 40 are any of Ag, Au, Al, and Pd with an fcc structure and (111) orientation, the intermediate layer 50 is Ru with a (200) orientation, and the magnetic recording layer 60 is an FePt alloy with an L10 structure and (001) orientation, the epitaxially grown columnar crystals will be more uniform. Furthermore, if the first underlayer 31 of the underlayer 30 is made of Cr with an fcc structure and (200) orientation, the crystal grains of the element α constituting the seed layer 40 are made of Ag, Au, Al, or Pd with an fcc structure and (200) orientation, the intermediate layer 50 is made of MgO, which is an NaCl-type compound and (200) oriented, and the magnetic recording layer 60 is made of an FePt alloy with an L10 structure and (001) orientation, the epitaxially grown columnar crystals will be more uniform. Among these, it is particularly preferable to use Ag as the element α.

[0045] One or more elements selected from the group consisting of Al, Si, Ga, and Ge may be added to magnetic particles having an L10 structure. The amount of these elements added is preferably 2 to 20 mol %, and more preferably 2.5 to 10 mol %. Adding these elements in the above amounts improves the orientation of the (001) plane of the magnetic recording layer 60.

[0046] The other configurations will be described.

[0047] The non-magnetic substrate 10 may be a metal substrate made of a metal material such as aluminum or an aluminum alloy, or a non-metal substrate made of a non-metal material such as glass, ceramics, silicon, silicon carbide, or carbon. It is also possible to use a metal or non-metal substrate having a NiP layer or NiP alloy layer formed on the surface thereof by, for example, plating or sputtering.

[0048] Soft magnetic underlayer 20 is provided to increase the component of magnetic flux generated from the magnetic head that is perpendicular to the surface of non-magnetic substrate 10, and to more firmly fix the direction of magnetization of magnetic recording layer 60, in which information is recorded, in a direction perpendicular to non-magnetic substrate 10. This effect is particularly noticeable when a single-pole head for perpendicular recording is used as the magnetic head for recording and reproduction.

[0049] For the soft magnetic underlayer 20, for example, a soft magnetic material containing Fe and Ni or Co and having an amorphous or microcrystalline structure can be used. Examples of soft magnetic materials include CoFe-based alloys (such as CoFeTaZr and CoFeZrNb), FeCo-based alloys (such as FeCo and FeCoV), FeNi-based alloys (such as FeNi, FeNiMo, FeNiCr, and FeNiSi), FeAl-based alloys (such as FeAl, FeAlSi, FeAlSiCr, FeAlSiTiRu, and FeAlO), FeCr-based alloys (such as FeCr, FeCrTi, and FeCrCu), FeTa-based alloys (such as FeTa, FeTaC, and FeTaN), FeMg-based alloys (such as FeMgO), FeZr-based alloys (such as FeZrN), FeC-based alloys, FeN-based alloys, FeSi-based alloys, FeP-based alloys, FeNb-based alloys, FeHf-based alloys, and FeB-based alloys.

[0050] The soft magnetic underlayer 20 is composed of two soft magnetic films, and preferably has a Ru film between the two soft magnetic films. By adjusting the thickness of the Ru film to within the range of 0.4 to 1.0 nm or 1.6 to 2.6 nm, the two soft magnetic films form an AFC structure. By having such an AFC structure, the soft magnetic underlayer 20 can suppress so-called spike noise.

[0051] The protective layer 70 suppresses corrosion of the magnetic recording layer 60 and also suppresses damage to the surface of the magnetic recording medium 1 when a magnetic head comes into contact with the magnetic recording medium 1. The protective layer 70 can be made of a material that has conventionally been used as a protective layer, such as a material containing C. The protective layer 70 can be made of, for example, a hard carbon film.

[0052] The thickness of the protective layer 70 is preferably 1 to 10 nm in order to reduce the distance between the head and the magnetic recording medium 1 and achieve high recording density in 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 is improved, and if it is 10 nm or less, the magnetic spacing is reduced, and the SNR (signal / noise ratio (S / N ratio)) of the magnetic recording medium 1 can be improved.

[0053] The lubricating layer 80 can be formed using a liquid lubricant layer. A liquid lubricant that is chemically stable, has low friction, and has low adsorption is preferably used. For example, the liquid lubricant is preferably a perfluoropolyether-based lubricant containing a compound having a perfluoropolyether structure, or a lubricant such as a fluorinated alcohol or a fluorinated carboxylic acid.

[0054] The thickness of the lubricating layer 80 is not particularly limited, but may be, for example, 1 to 3 nm.

[0055] In addition, the magnetic recording medium 1 may include any appropriate layers in addition to the protective layer 70 and the lubricating layer 80. For example, the magnetic recording medium 1 may include an adhesion layer, a soft magnetic underlayer, an orientation control layer, etc. between any of the non-magnetic substrate 10, the underlayer 30, and the magnetic recording layer 60, as needed. The soft magnetic underlayer may include, for example, a first soft magnetic layer, an intermediate layer, and a second soft magnetic layer. The orientation control layer may be a single layer, or may be two or more layers (for example, a first orientation control layer, a second orientation control layer, etc.). Materials for forming the adhesion layer, soft magnetic underlayer, orientation control layer, etc. may be materials commonly used in magnetic recording media.

[0056] [Magnetic recording medium manufacturing method] A method for manufacturing a magnetic recording medium according to this embodiment will be described. In this embodiment, the manufacturing of a magnetic recording medium 1 will be described as an example of a method for manufacturing a magnetic recording medium.

[0057] The method for manufacturing the magnetic recording medium according to this embodiment is a method for manufacturing a magnetic recording medium 1 having an underlayer 30, a seed layer 40, and a magnetic recording layer 60 on a non-magnetic substrate 10 in this order. The seed layer 40 is formed as a film containing two elements, element α and element β, where element α is formed as a columnar crystal with a mainly fcc structure and element β is formed as a mainly amorphous structure, and then the surface of the film is etched to form a surface where element α and element β are phase-separated from each other.

[0058] In the method for manufacturing a magnetic recording medium according to this embodiment, soft magnetic underlayers 20 are formed on both sides of non-magnetic substrate 10 using a sputtering method or the like.

[0059] Next, the underlayer 30 is formed on the surface of the soft magnetic underlayer 20 that is different from the surface on which the non-magnetic substrate 10 is formed.

[0060] The underlayer 30 is formed by stacking a first underlayer 31, a second underlayer 32, and a third underlayer 33 in this order from the non-magnetic substrate 10 side. The method for forming each of the first underlayer 31, the second underlayer 32, and the third underlayer 33 is not particularly limited, and a general thin film forming method, such as a sputtering method, may be used.

[0061] Next, the seed layer 40 is formed on a surface of the underlayer 30 that is different from the surface of the soft magnetic underlayer 20. The method for forming the seed layer 40 is not particularly limited, and a general thin film forming method such as sputtering may be used.

[0062] In this embodiment, such a seed layer 40 is formed by depositing a film containing two elements, element α and element β, so that the element α is mainly formed as columnar crystals with an fcc structure and the element β is mainly formed as an amorphous structure, and then etching the surface to form a surface where the elements α and β are phase-separated from each other.

[0063] The seed layer 40 of this embodiment has the effect of epitaxially growing the crystal grains of the layer formed thereon as continuous columnar crystals in the thickness direction, while having a 1:1 correspondence with the crystal grains of the seed layer 40. However, by clearly separating the phases of the elements α and β at the surface of the seed layer 40, which is the starting point of the epitaxial growth, the epitaxially grown columnar crystals become more uniform.

[0064] In this embodiment, after forming a surface where the elements α and β are phase-separated, it is preferable to further form a film of an alloy containing the element α as a main component on the surface. An alloy containing the element α as a main component is one in which the element α is the most abundant component of the alloy, preferably including a case in which the element α is 50% or more and all of the elements constituting the alloy are the element α. This reduces defects on the crystal surface of the element α, further reduces the amount of element β covering the surface of the element α, and forms a dome-shaped crystal surface of the element α, making it easier to epitaxially grow the crystal grains of a layer formed thereon as continuous columnar crystals in the thickness direction, with a 1:1 correspondence to the crystal grains of the element α.

[0065] In this embodiment, dry etching using an inert gas is preferably used to etch the film containing two elements, element α and element β. Examples of inert gases include argon, helium, xenon, neon, krypton, and nitrogen. Among these, argon gas is particularly preferred. By using argon gas, phase separation of element α and element β on the surface of the seed layer 40 can be more clearly achieved.

[0066] Next, the intermediate layer 50 is formed on a surface of the seed layer 40 that is different from the surface of the underlayer 30. The method for forming the intermediate layer 50 is not particularly limited, and a general thin film forming method, such as a sputtering method, may be used.

[0067] Next, magnetic recording layer 60 is formed on a surface of intermediate layer 50 that is different from the surface of seed layer 40. The method for forming magnetic recording layer 60 is not particularly limited, and a general thin film forming method, such as sputtering, may be used.

[0068] Next, the protective layer 70 is formed on the surface of the magnetic recording layer 60 that is different from the surface on which the intermediate layer 50 is formed.

[0069] Examples of methods for forming the protective layer include RF-CVD (Radio Frequency-Chemical Vapor Deposition), which forms a film by decomposing hydrocarbon gas (raw material gas) using high-frequency plasma; IBD (Ion Beam Deposition), which forms a film by ionizing raw material gas with electrons emitted from a filament; and FCVA (Filtered Cathodic Vacuum Arc), which forms a film using a solid carbon target without using a raw material gas.

[0070] Next, lubricating layer 80 is formed by a general coating method, such as a coating method, on the surface of protective layer 70 that is different from the surface on which magnetic recording layer 60 is formed. This results in magnetic recording medium 1 shown in FIG.

[0071] As described above, the method for manufacturing a magnetic recording medium according to this embodiment forms the seed layer 40 as a film containing two elements, element α and element β, with the element α being primarily columnar crystals with an fcc structure and the element β being primarily amorphous, and then etching the surface to form a surface in which the elements α and β are phase-separated from each other. By clearly defining the phase separation between the elements α and β on the surface of the seed layer 40, the seed layer 40 can form more uniform columnar crystals on the seed layer 40 by epitaxially growing the crystal grains of layers formed on the seed layer 40, such as the intermediate layer 50 and the magnetic recording layer 60, continuously in the thickness direction. Therefore, the method for manufacturing a magnetic recording medium according to this embodiment can improve the perpendicular orientation of the magnetic recording layer 60, enabling even higher recording densities.

[0072] In the method for manufacturing a magnetic recording medium according to this embodiment, it is preferable to form a surface in which the elements α and β are phase-separated when forming the seed layer 40, and then to deposit an alloy primarily containing the element α on that surface. The seed layer 40 facilitates continuous epitaxial growth of crystal grains in the thickness direction of layers formed on the seed layer 40, such as the intermediate layer 50 and the magnetic recording layer 60, thereby facilitating the formation of more 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 perpendicular orientation of the magnetic recording layer 60 and further increase the recording density.

[0073] In the method for manufacturing a magnetic recording medium according to this embodiment, argon gas is preferably used to etch a film containing two elements, element α and element β, during the formation of the seed layer 40. By using argon gas, phase separation between element α and element β on the surface of the seed layer 40 can be more clearly achieved. This facilitates continuous epitaxial growth of crystal grains in the thickness direction of layers formed on the seed layer 40, such as the intermediate layer 50 and the magnetic recording layer 60, and thus facilitates the formation of more 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 perpendicular orientation of the magnetic recording layer 60 and further increase the recording density.

[0074] In the method for manufacturing a magnetic recording medium according to this embodiment, the underlayer 30 is formed to include, from the non-magnetic substrate 10 side, a first underlayer 31, a second underlayer 32, and a third underlayer 33. Preferably, the first underlayer 31 contains primarily any of Ru, Cr, and Ni, the second underlayer 32 contains primarily the element α, and the third underlayer 33 contains primarily any of Ru, Cr, and Mo. This arrangement enhances the (111) plane orientation or the (200) plane orientation and suppresses unintended element diffusion into the seed layer 40 when the columnar crystals of the element α contained in the seed layer 40 have an fcc structure. This facilitates the formation of columnar crystals with enhanced (111) plane orientation or (200) plane orientation on the seed layer 40 in layers formed on the seed layer 40, such as the intermediate layer 50 and the magnetic recording layer 60. Therefore, the method for manufacturing a magnetic recording medium according to this embodiment can further improve the perpendicular orientation of the magnetic recording layer 60 and further increase the recording density.

[0075] In the method for manufacturing a magnetic recording medium according to this embodiment, it is preferable that the element α is any one of Ag, Au, Al, and Pd, and the element β is any one of Ge and Si. This allows the crystal grains of layers formed on the seed layer 40, such as the intermediate layer 50 and the magnetic recording layer 60, to grow epitaxially continuously and more uniformly in the thickness direction, thereby forming more 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 perpendicular orientation of the magnetic recording layer 60 and further increase the recording density.

[0076] In the method for manufacturing a magnetic recording medium according to this embodiment, it is preferable that the intermediate layer 50 be a layer containing primarily Ru, and the magnetic recording layer 60 be a layer containing primarily Co, Cr, and Pt. This allows the crystal grains of the magnetic recording layer 60 formed on the intermediate layer 50 to grow epitaxially more uniformly and continuously in the thickness direction, so that the magnetic recording layer 60 can be formed with more uniform columnar crystals. Therefore, the method for manufacturing a magnetic recording medium according to this embodiment can further improve the perpendicular orientation of the magnetic recording layer 60, and further improve the recording density.

[0077] In the method for manufacturing a magnetic recording medium according to this embodiment, it is preferable that the intermediate layer 50 primarily contains an NaCl-type compound, and the magnetic recording layer 60 primarily contains magnetic grains having an L10 structure. This allows the crystal grains of the magnetic recording layer 60 formed on the intermediate layer 50 to grow epitaxially more uniformly and continuously in the thickness direction, so that the magnetic recording layer 60 can be formed with more uniform columnar crystals. Therefore, the method for manufacturing a magnetic recording medium according to this embodiment can further improve the perpendicular orientation of the magnetic recording layer 60, thereby further improving the recording density.

[0078] The method for manufacturing a magnetic recording medium according to this embodiment can manufacture a magnetic recording medium 1 having the above-described characteristics, and therefore, even if a thermally assisted recording method or a microwave assisted recording method is used as the recording method for the obtained magnetic recording medium 1, the magnetic recording layer 60 has a high recording density, and magnetic information can be sufficiently recorded on the magnetic recording layer 60 by the recording magnetic field of a magnetic head. Therefore, the magnetic recording medium 1 obtained by the method for manufacturing a magnetic recording medium according to this embodiment can be suitably used in a magnetic recording and reproducing device having an even higher recording density.

[0079] [Magnetic recording and playback device] A magnetic recording and reproducing device (also referred to as a "magnetic recording device") equipped with the magnetic recording medium according to this embodiment will be described. The magnetic recording and reproducing device according to this embodiment is not particularly limited in form as long as it has the magnetic recording medium according to this embodiment.

[0080] 2 is a perspective view showing an example of a magnetic recording and reproducing device that uses the magnetic recording medium according to this embodiment. As shown in FIG. 2, the magnetic recording and reproducing device 100 includes a perpendicular magnetic recording medium 101, a medium drive unit 102 that rotates the perpendicular magnetic recording medium 101, a magnetic head 103 that records and reproduces information on the perpendicular magnetic recording medium 101, a head drive unit 104 that moves the magnetic head 103 relative to the perpendicular magnetic recording medium 101, and a recording and reproducing signal processing system 105. The perpendicular magnetic recording medium 101 is the magnetic recording medium 1 shown in FIG. 1 above. The recording and reproducing signal processing system 105 processes data input from an external device and sends a recording signal to the magnetic head 103, and processes a reproduction signal from the magnetic head 103 and sends the data to the outside.

[0081] In the magnetic recording and reproducing device 100, the magnetic recording medium 1 can have even better recording characteristics (OW), and therefore the magnetic recording and reproducing device 100 can have excellent high-density recording.

[0082] Although the embodiments have been described above, they are presented as examples and the present invention is not limited to the above embodiments. The above embodiments can be implemented in various other forms, and various combinations, omissions, substitutions, modifications, etc. can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as set forth in the claims. [Example]

[0083] Hereinafter, the present embodiment will be described in more detail with reference to examples, but the present embodiment is not limited to these examples.

[0084] Example 1 (Magnetic Recording Medium Manufacturing Method) In Example 1, a cleaned glass substrate (manufactured by HOYA Corporation, outer diameter 3.5 inches) was placed in the chamber of a film forming apparatus (C-3010 manufactured by ANELVA Corporation) and the ultimate vacuum was 1×10 -5The deposition chamber was evacuated to a vacuum of 10 Pa. Then, a 10 nm thick adhesion layer was formed on a glass substrate by DC magnetron sputtering using a Cr target. A 25 nm thick soft magnetic underlayer was formed on this adhesion layer by DC magnetron sputtering using a Co-20Fe-5Zr-5Ta {Fe content 20 atomic %, Zr content 5 atomic %, Ta content 5 atomic %, balance Co} target at a substrate temperature of 100°C or less. A 0.7 nm thick Ru layer was then formed on the soft magnetic underlayer by DC magnetron sputtering, and a 25 nm thick soft magnetic underlayer was then formed again by DC magnetron sputtering using a Co-20Fe-5Zr-5Ta target.

[0085] Next, a first underlayer having a thickness of 5 nm was formed on the soft magnetic underlayer by DC magnetron sputtering using a target of 82Ni-3W-15Fe {W content 3 atomic %, Fe content 15%, balance Ni}.

[0086] Next, a second underlayer having a thickness of 2 nm was formed on the first underlayer by DC magnetron sputtering using an Ag target.

[0087] Next, a third underlayer having a thickness of 0.3 nm was formed on the second underlayer by DC magnetron sputtering using a Ru target.

[0088] Next, a seed layer was formed on the third underlayer. A 5-nm-thick film was formed by RF sputtering using a 40Ag-60Ge target with Ag as the element α and Ge as the element β, and then the surface was dry-etched using argon gas. The dry etching was performed with an argon gas pressure of 7 Pa in the processing equipment and a substrate bias of 200 V, 250 kHz, and 1616 ns pulse bias. The etching time was 7 seconds. A 1-nm-thick film was then formed by DC magnetron sputtering using an Ag target.

[0089] Next, a 20 nm thick intermediate layer was formed using a Ru target. The sputtering pressure was 0.8 Pa to form a 10 nm thick Ru film, and then the sputtering pressure was 1.5 Pa to form a 10 nm thick Ru film.

[0090] Next, a three-layer magnetic recording layer was deposited on the intermediate layer by DC magnetron sputtering. Specifically, a 9-nm-thick first magnetic recording layer was deposited using a target of 91(Co15Cr16Pt)-6(SiO2)-3(TiO2) (Cr content 15 atomic %, Pt content 16 atomic %, the remainder being an alloy of 91 mol % Co, 6 mol % oxide of SiO2, and 3 mol % oxide of TiO2). The sputtering pressure was 2 Pa.

[0091] Next, a 6-nm-thick second magnetic recording layer was deposited on the first magnetic recording layer using a target of 92(Co11Cr18Pt)-5(SiO2)-3(TiO2) (11 atomic % Cr, 18 atomic % Pt, and the remainder being 92 mol % Co alloy, 5 mol % SiO2 oxide, and 3 mol % TiO2 oxide). The sputtering pressure was 2 Pa.

[0092] Next, a third magnetic recording layer with a thickness of 7 nm was deposited on the second magnetic recording layer using a target of Co20Cr14Pt3B (Cr content 20 atomic %, Pt content 14 atomic %, B content 3 atomic %, balance Co) at a sputtering pressure of 0.6 Pa.

[0093] Next, a protective layer having a thickness of 3 nm was formed on the third magnetic recording layer by a CVD method, and then a lubricating film made of perfluoropolyether was formed to a thickness of 1 nm by a dipping method, thereby obtaining the magnetic recording medium of Example 1. The configuration of each layer of the produced magnetic recording medium is shown in Tables 1 to 3.

[0094] The magnetic recording media thus fabricated were observed using a transmission electron microscope (JEM-ARM200F NEOARM, manufactured by JEOL Ltd., accelerating voltage: 200 kV) to measure the average particle size D of the magnetic particles constituting the first to third magnetic recording layers, and the particle size dispersion σ / D normalized by this average particle size D. The c-axis orientation dispersion (Δθ50) of the intermediate layer was also evaluated using X-ray diffraction. Δθ50 was measured using the diffraction peak of the (002) plane, regardless of whether the intermediate layer was composed of Ru or MgO. The evaluation results are shown in Tables 2 and 3. Note that 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 and the higher the orientation.

[0095] Tables 1 to 3 show the manufacturing conditions for the magnetic particles in the first to third underlayers, seed layer, intermediate layer, and magnetic recording layer of the magnetic recording medium.

[0096] (Magnetic properties of magnetic recording media) The magnetic properties (coercive force Hc, saturation magnetic field strength Hs) of the magnetic recording medium were measured using a magneto-optical Kerr effect measuring device. The measurement results are shown in Table 3.

[0097] <Examples 2 to 13 and Comparative Examples 1 to 8> Magnetic recording media were fabricated in the same manner as in Example 1, but the manufacturing conditions for the first to third underlayers, seed layer, intermediate layer, and magnetic recording layer were changed as shown in Tables 1 to 3. In Examples 1 to 8, Comparative Examples 1 to 8 were cases in which argon gas etching and deposition of element α were not performed to form the seed layer. In addition, Examples 9 to 13 were cases in which the conditions for argon gas etching and deposition of element α were changed in Example 1. Note that the substrate temperature was 250°C when depositing the intermediate layer made of MgO in Example 6, and 450°C when depositing the magnetic recording layer made of FePt. The evaluation results are shown in Tables 2 and 3.

[0098] [Table 1]

[0099] [Table 2]

[0100] [Table 3]

[0101] As can be seen from Tables 2 and 3, the magnetic recording media of each example exhibited higher coercivity Hc and saturation magnetic field strength Hs than the comparative examples manufactured using magnetic particles in the magnetic recording layer having the same composition, thereby improving the magnetic properties.

[0102] Therefore, when forming a seed layer on the underlayer, a film containing two elements, element α and element β, is formed, with element α being mainly columnar crystals with an fcc structure and element β being mainly amorphous, and then the surface is etched to form a surface where element α and element β are phase-separated from each other, thereby forming a seed layer.It has been confirmed that this improves the magnetic properties of the magnetic recording layer of the manufactured magnetic recording medium.Therefore, the magnetic recording medium obtained by the magnetic recording medium manufacturing method of each embodiment has a magnetic recording layer with a high recording density, and when used in a magnetic storage device, it can be said that the magnetic storage device can have a high recording capacity. [Explanation of symbols]

[0103] 1. Magnetic recording media 10 Non-magnetic substrate 20 Soft magnetic underlayer 30 Base layer 31 First base layer 32 Second base layer 33 Third Underlayer 40 seed layer 50 Middle Class 60 Magnetic Recording Layer 70 protective layer 80 Lubricating layer 100 Magnetic recording and reproducing device 101 Perpendicular magnetic recording media

Claims

1. 1. A method for manufacturing a magnetic recording medium having an underlayer, a seed layer, and a magnetic recording layer on a non-magnetic substrate in this order, comprising: A method for manufacturing a magnetic recording medium, wherein the seed layer is formed as a film containing two elements, element α and element β, in which the element α is formed as a columnar crystal with a fcc structure and the element β is formed as a amorphous structure, and then the surface of the film is etched to form a surface in which the element α and the element β are phase-separated from each other.

2. 2. The method for producing a magnetic recording medium according to claim 1, wherein after forming a surface in which the element α and the element β are phase-separated from each other, a film of an alloy mainly containing the element α is further formed on the surface.

3. 3. The method for manufacturing a magnetic recording medium according to claim 1, wherein argon gas is used for the etching.

4. the underlayer is formed to include, from the non-magnetic substrate side, a first underlayer, a second underlayer, and a third underlayer; the first underlayer mainly contains any one of Ru, Cr, and Ni; the second underlayer mainly contains the element α, 3. The method for manufacturing a magnetic recording medium according to claim 1, wherein the third underlayer mainly contains any one of Ru, Cr, and Mo.

5. the element α is any one of Ag, Au, Al, and Pd, 3. The method for manufacturing a magnetic recording medium according to claim 1, wherein the element β is either Ge or Si.

6. forming an intermediate layer between the seed layer and the magnetic recording layer; the intermediate layer is a layer mainly containing Ru, 3. The method for manufacturing a magnetic recording medium according to claim 1, wherein the magnetic recording layer is a layer containing mainly Co, Cr, and Pt.

7. forming an intermediate layer between the seed layer and the magnetic recording layer; the intermediate layer primarily comprises an NaCl-type compound; The magnetic recording layer is L1 ０ 3. The method for producing a magnetic recording medium according to claim 1, wherein the magnetic recording medium mainly contains magnetic particles having a structure.

8. a magnetic recording medium; the magnetic recording medium comprises an underlayer, a seed layer, and a magnetic recording layer, in this order, on a non-magnetic substrate; The seed layer is formed as a film containing two elements, element α and element β, in which the element α is formed as a columnar crystal with a fcc structure and the element β is formed as a amorphous structure, and then the surface of the film is etched to form a surface in which the element α and the element β are phase-separated from each other.

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