WO2011087078A1 - Magnetic recording medium manufacturing method and magnetic read/write device - Google Patents

Magnetic recording medium manufacturing method and magnetic read/write device Download PDF

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Publication number
WO2011087078A1
WO2011087078A1 PCT/JP2011/050519 JP2011050519W WO2011087078A1 WO 2011087078 A1 WO2011087078 A1 WO 2011087078A1 JP 2011050519 W JP2011050519 W JP 2011050519W WO 2011087078 A1 WO2011087078 A1 WO 2011087078A1
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Prior art keywords
layer
magnetic
magnetic recording
recording medium
mask layer
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PCT/JP2011/050519
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French (fr)
Japanese (ja)
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正人 福島
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昭和電工株式会社
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    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
    • G11B5/84—Processes or apparatus specially adapted for manufacturing record carriers
    • G11B5/855—Coating only part of a support with a magnetic layer

Definitions

  • the present invention relates to a method for manufacturing a magnetic recording medium used in a hard disk drive (HDD) and the like, and a magnetic recording / reproducing apparatus.
  • the track density has reached 250 kTPI.
  • magnetic recording information between adjacent tracks interferes with each other, and the problem that the magnetization transition region in the boundary region becomes a noise source and the SNR is easily lost. This leads to a deterioration of the bit error rate, which is an obstacle to improvement of the recording density.
  • Such a technique is generally called a discrete track method, and a magnetic recording medium manufactured by the technique is called a discrete track medium.
  • a so-called patterned medium in which the data area in the same track is further divided.
  • a magnetic recording medium using a nonmagnetic substrate having a concavo-convex pattern formed on a surface, forming a magnetic layer thereon, and forming physically separated magnetic recording tracks and servo signal patterns is known (see, for example, Patent Document 1).
  • a ferromagnetic layer is formed on the surface of a substrate having a plurality of irregularities on the surface via a soft magnetic layer, and a protective film is formed on the surface.
  • a magnetic recording area physically separated from the periphery is formed in the convex area.
  • this magnetic recording medium the occurrence of a domain wall in the soft magnetic layer can be suppressed, so that the influence of thermal fluctuation is difficult to occur, and there is no interference between adjacent signals, so that a high-density magnetic recording medium with less noise can be formed. ing.
  • the discrete track method includes a method of forming a track after forming a magnetic recording medium consisting of several thin films, and a magnetic pattern after forming a concavo-convex pattern directly on the substrate surface in advance or on a thin film layer for track formation.
  • a method of forming a thin film of a recording medium see, for example, Patent Documents 2 and 3).
  • the former method is called a magnetic layer processing type.
  • the latter method since the surface is physically processed after the medium is formed, there is a disadvantage that the medium is easily contaminated in the manufacturing process and the manufacturing process becomes very complicated.
  • the latter method is called an embossing die.
  • the medium is not easily contaminated during the manufacturing process, the uneven shape formed on the substrate is inherited by the film formed thereon, so that recording is performed while floating on the medium.
  • the flying posture of the recording / reproducing head for performing reproduction and the flying height become unstable.
  • the magnetic track area of the discrete track medium is formed by injecting ions such as nitrogen and oxygen into a previously formed magnetic layer or by irradiating a laser to change the magnetic characteristics of the portion.
  • a method is disclosed (see, for example, Patent Document 4).
  • a magnetic recording pattern magnetically separated is formed in the magnetic layer by partially implanting ions into the magnetic layer and changing the magnetic characteristics of the portion.
  • a resist layer is provided on the mask layer in order to pattern the mask layer. Then, after implanting ions into the magnetic layer, these mask layer and resist layer are removed.
  • Dry etching is used to remove the resist layer and the mask layer. Dry etching is a method in which a solid substance constituting a resist layer or a mask layer is reacted with a gas to gasify and remove the solid substance. For example, in the case of a C-based solid material, a method of removing it as a CO-based gas or a CN-based gas using oxygen gas or nitrogen gas, and in the case of a SiO 2 -based solid material, this is performed using CF 4 -based gas. A method of removing it as a halogenated gas is known.
  • the surface of the magnetic layer is oxidized, nitrided, or halogenated, so that the oxide, nitride, halogen It has been clarified by the inventor's examination that a compound or the like deteriorates the electromagnetic conversion characteristics of a magnetic recording medium.
  • the present invention has been proposed in order to solve the above-described problems, and uses a method for manufacturing a magnetic recording medium capable of obtaining excellent electromagnetic conversion characteristics, and a magnetic recording medium manufactured by such a manufacturing method.
  • An object of the present invention is to provide a magnetic recording / reproducing apparatus.
  • the present invention provides the following means. (1) A method of manufacturing a magnetic recording medium having magnetically separated magnetic recording patterns, Forming a magnetic layer on at least one surface of the nonmagnetic substrate; Forming a release layer on the magnetic layer; Forming a mask layer on the release layer; Patterning the mask layer and the release layer into a shape corresponding to the magnetic recording pattern; A step of partially modifying or removing a portion of the magnetic layer that is not covered with the mask layer and the release layer; Removing the mask layer and the release layer, When removing the mask layer and the release layer, the release layer is reduced and removed using a reducing gas substantially free of oxygen, nitrogen, and halogen, so that the mask layer and the release layer are magnetically removed.
  • a method of manufacturing a magnetic recording medium comprising removing the layer from above.
  • (2) before patterning the mask layer including a step of forming a resist layer patterned into a shape corresponding to the magnetic recording pattern on the mask layer; After patterning the mask layer into a shape corresponding to the magnetic recording pattern using the resist layer and partially modifying or removing the magnetic layer using the patterned mask layer, the reducing gas is used.
  • the method for producing a magnetic recording medium according to (1) characterized in that the mask layer and the resist layer are removed together with the release layer from the top of the magnetic layer by reducing and removing the release layer using an adhesive.
  • a magnetic recording medium manufactured by the manufacturing method according to any one of (1) to (4) A medium driving unit for driving the magnetic recording medium in a recording direction; A magnetic head for performing a recording operation and a reproducing operation on the magnetic recording medium; Head moving means for moving the magnetic head relative to a magnetic recording medium; A magnetic recording / reproducing apparatus comprising: a recording / reproducing signal processing means for inputting a signal to the magnetic head and reproducing an output signal from the magnetic head.
  • the mask layer is removed together with the release layer from the magnetic layer by reducing and removing the release layer using a reducing gas substantially free of oxygen, nitrogen, and halogen. Therefore, the surface of the magnetic layer is not oxidized, nitrided or halogenated, and as a result, a magnetic recording medium having excellent electromagnetic conversion characteristics can be manufactured. Further, in the magnetic recording / reproducing apparatus provided with such a magnetic recording medium having excellent electromagnetic conversion characteristics, it is possible to further improve the recording density.
  • FIG. 1 is a cross-sectional view for explaining an example of a method of manufacturing a magnetic recording medium to which the present invention is applied.
  • FIG. 2 is a cross-sectional view for explaining another example of a method of manufacturing a magnetic recording medium to which the present invention is applied.
  • FIG. 3 is a perspective view showing a configuration example of the magnetic recording / reproducing apparatus.
  • the method of manufacturing a magnetic recording medium to which the present invention is applied is a non-magnetic method as shown in FIGS. 1A to 1G, for example, when manufacturing a magnetic recording medium having a magnetically separated magnetic recording pattern.
  • a step of forming a magnetic layer 2 on at least one surface of the substrate 1, a step of forming a release layer 3 on the magnetic layer, a step of forming a mask layer 4 on the release layer 3, and a mask layer 4 Forming the resist layer 5 on the substrate, patterning the surface of the resist layer 5 into a shape corresponding to the magnetic recording pattern, and patterning the mask layer 4 and the release layer 3 using the patterned resist layer 5.
  • a magnetic layer 2, a release layer 3, and a mask layer 4 are sequentially laminated on a nonmagnetic substrate 1. To form.
  • the nonmagnetic substrate 31 examples include an Al alloy substrate mainly composed of Al, such as an Al—Mg alloy, a glass substrate such as soda glass, aluminosilicate glass, or crystallized glass, a silicon substrate, a titanium substrate, a ceramic substrate, Various substrates such as a resin substrate can be mentioned, and among them, an Al alloy substrate, a glass substrate, and a silicon substrate are preferably used. Further, the average surface roughness (Ra) of the nonmagnetic substrate 31 is preferably 1 nm or less, more preferably 0.5 nm or less, and further preferably 0.1 nm or less.
  • the magnetic layer 2 may be an in-plane magnetic layer for an in-plane magnetic recording medium or a perpendicular magnetic layer for a perpendicular magnetic recording medium, but a perpendicular magnetic layer is preferable in order to realize a higher recording density.
  • the magnetic layer 2 is preferably formed of an alloy mainly containing Co as a main component.
  • the magnetic layer 2 for perpendicular magnetic recording media for example, soft magnetic FeCo alloys (FeCoB, FeCoSiB, FeCoZr, FeCoZrB, FeCoZrBCu, etc.), FeTa alloys (FeTaN, FeTaC, etc.), Co alloys (CoTaZr, CoZrNB, CoB) Etc.), an intermediate layer made of Ru, etc., and a recording magnetic layer made of 60Co-15Cr-15Pt alloy or 70Co-5Cr-15Pt-10SiO 2 alloy can be used. Further, an orientation control film made of Pt, Pd, NiCr, NiFeCr or the like may be laminated between the soft magnetic layer and the intermediate layer.
  • a laminate of a nonmagnetic CrMo underlayer and a ferromagnetic CoCrPtTa magnetic layer can be used as the magnetic layer 2 for the in-plane magnetic recording medium.
  • the thickness of the recording magnetic layer is 3 nm or more and 20 nm or less, preferably 5 nm or more and 15 nm or less, and may be formed so as to obtain sufficient head input / output according to the type of magnetic alloy used and the laminated structure.
  • the recording magnetic layer needs to have a film thickness of a certain degree or more in order to obtain an output of a certain level or more during reproduction, while parameters indicating recording / reproduction characteristics usually deteriorate as the output increases. Therefore, it is necessary to set an optimum film thickness.
  • the recording magnetic layer is usually formed as a thin film by sputtering.
  • the release layer 3 is made of a material that can be reduced and removed by a reducing gas that does not substantially contain oxygen, nitrogen, or halogen.
  • a reducing gas that does not substantially contain oxygen, nitrogen, or halogen.
  • examples of such substances include carbon, novolak resins, acrylic esters, alicyclic epoxies, and the like. In the present invention, novolak resins are used for ease of etching with reducing gas. It is preferable.
  • a carbon film is preferably used as the mask layer 4.
  • the carbon film can be formed by a sputtering method, a CVD method, or the like, but a carbon film with higher density can be formed by using the CVD method.
  • the thickness of the mask layer 4 is preferably in the range of 5 nm to 40 nm, more preferably in the range of 10 nm to 30 nm. If the thickness of the mask layer 4 is less than 5 nm, the edge portion of the mask layer 4 will fall and the magnetic recording pattern formation characteristics will deteriorate. In addition, ions that have passed through the resist layer 5, the mask layer 4, and the release layer 3 enter the magnetic layer 2, and deteriorate the magnetic properties of the magnetic layer 2. On the other hand, when the thickness of the mask layer 4 is greater than 40 nm, the etching time of the mask layer 4 becomes longer and the productivity is lowered.
  • the resist layer 5 is formed into a magnetic recording pattern by using, for example, a photolithography method or a nanoimprint method. Pattern to the corresponding shape.
  • FIG.1 (c) the uneven
  • a normal photolithography technique can be used as a method for forming the concavo-convex pattern on the resist layer 5.
  • a method of transferring the negative pattern to the resist layer 5 using a stamp having a negative pattern of the magnetic recording pattern is used. It is preferable from the viewpoint of work efficiency.
  • the resist layer 5 is made of a material that is curable by radiation irradiation.
  • a negative pattern of a magnetic recording pattern is transferred to the resist layer 5 using a stamp, or after the pattern transfer step, the resist layer 5 It is preferable to irradiate with radiation. This makes it possible to accurately transfer the stamp shape to the resist layer 5, eliminates sagging of the edge portion of the carbon mask layer 4 in the etching process of the mask layer 4 to be described later, and prevents the mask layer 4 against milling ions.
  • the shielding property can be improved, and the magnetic recording pattern forming characteristics by the mask layer 4 can be improved.
  • the resist layer 5 in the step of transferring a negative pattern using a stamp to the resist layer 5, the resist layer 5 is pressed with a high fluidity, and the resist layer 5 is pressed, and in the pressed state, By irradiating the resist layer 5 with radiation, the resist layer 5 is cured, and then the stamp is separated from the resist layer 5 so that the shape of the stamp can be transferred to the resist layer 5 with high accuracy.
  • a method of irradiating radiation from the opposite side of the stamp that is, the non-magnetic substrate 1 side, a substance capable of transmitting radiation as a stamp material
  • the method of irradiating radiation from the stamp side, the method of irradiating radiation from the side of the stamp, the heat conduction from the stamp or the non-magnetic substrate 1 using radiation having high conductivity with respect to a solid such as heat rays The method of irradiating with radiation can be used.
  • the radiation in this invention means the electromagnetic waves of wide concepts, such as a heat ray, visible light, an ultraviolet-ray, an X-ray, a gamma ray.
  • the material that is cured by irradiation with radiation include a thermosetting resin for heat rays and an ultraviolet curable resin for ultraviolet rays.
  • SiO 2 resist it is preferable to use a SiO 2 resist, and it is particularly preferable to use SOG (Spin On Glass).
  • the SiO 2 resist is highly resistant to dry etching using oxygen gas, and can reduce image blur when forming a concavo-convex pattern corresponding to the magnetic recording pattern on the mask layer 4 made of a carbon film. it can. That is, the mask layer 4 made of a carbon film can be easily processed by dry etching using oxygen gas, while the SiO 2 resist is highly resistant to dry etching using oxygen gas. Then, it becomes possible to process the mask layer 4 into a vertically vertical shape by dry etching, and as a result, a sharp magnetic recording pattern can be formed on the magnetic layer 2.
  • a stamper in which a fine track pattern is formed on a metal plate by using a method such as electron beam drawing can be used as the stamp. Further, since the stamper is required to have hardness and durability that can withstand the above process, for example, Ni or the like is used. However, the material is not particularly limited as long as it meets the above purpose. . Further, in addition to the track for recording normal data, a servo signal pattern such as a burst pattern, a gray code pattern, and a preamble pattern can be formed on the stamp.
  • the thickness of the concave portion 5b of the resist layer 5 is preferably in the range of 0 to 20 nm. This eliminates sagging of the edge portion of the mask layer 4 in the etching process of the mask layer 4, the release layer 3, and the magnetic layer 2, which will be described later, and improves the shielding property against milling ions of the mask layer 4. 4 can improve the formation characteristics of the magnetic recording pattern.
  • the width W of the convex portion 5a is 200 nm or less
  • the width L of the concave portion 5b is preferably 100 nm or less
  • the width W of the convex portion 5a is the width of the magnetic portion (magnetic recording pattern) of the magnetic layer 2
  • the width L of the concave portion 5b is the width of the nonmagnetic portion (recessed portion or modified portion) of the magnetic layer 2. This is because the width P becomes the track pitch, and in order to increase the recording density, it is preferable to make these widths as narrow as possible.
  • the recess 5 b of the resist layer 5, the mask layer 4 and the peeling layer 3 immediately below the resist layer 5 are removed by dry etching using the patterned resist layer 5.
  • the mask layer 4 and the release layer 3 can be patterned into a shape corresponding to the magnetic recording pattern, and the magnetic layer 2 is exposed from between the patterned mask layer 4 and the release layer 3.
  • the resist layer 5 is formed on the mask layer 4, it is possible to prevent the corners of the mask layer 4 from being rounded, and patterning is performed in a vertically standing shape.
  • dry etching such as reactive ion etching or ion milling can be used. Among them, reactive ion etching using an ICP (Inductively Coupled Plasma) apparatus is particularly preferable.
  • ICP Inductively Coupled Plasma
  • dry etching such as reactive ion etching or ion milling can be used.
  • a reactive ion etching apparatus such as ICP or RIE is used. It is preferable to carry out by introducing an inert gas such as Ar gas or N 2 gas.
  • oxygen gas is preferably used, but the subsequent dissolved layer 3 and
  • the dry etching of the magnetic layer 2 is preferably performed by introducing an inert gas such as Ar gas or N 2 gas using a reactive ion etching apparatus such as ICP or RIE. That is, in the present invention, the milling ions of the mask layer 4 and the milling ions of the release layer 3 and the magnetic layer 2 are optimum, for example, the mask layer 4 is an ICP using oxygen gas, and the release layer 3 and the magnetic layer 2 are It is preferable to change to ion milling using Ar, N 2 gas.
  • the remaining edge portion of the magnetic layer 2 can be formed vertically. This is because the peeling layer 3 and the mask layer 4 on the magnetic layer 2 are vertically cut, and the magnetic layer 2 therebelow has the same shape. Thereby, the magnetic layer 2 (magnetic recording pattern 2a) having excellent fringe characteristics can be formed. Even if N 2 gas is used for ion milling in this step, the surface of the magnetic recording pattern 2a is protected by the release layer 3 and the mask layer 4, so that the surface of the magnetic recording pattern 2a is nitrided and has magnetic characteristics. Will not worsen.
  • the release layer 3 is reduced and removed using a reducing gas substantially free of oxygen, nitrogen, and halogen, so that the release layer 3 and the mask layer 4 and The resist layer 5 is removed from above the magnetic layer 2.
  • dry etching is generally used for removing the resist layer 4 and the mask layer 3
  • oxygen, nitrogen, and halogen are generally used as gases having a large etching power. That is, these etching gases are removed as oxides, nitrides, and halides such as CO and CO 2 while oxidizing, nitriding, and halogenating the object to be etched.
  • the magnetic layer 2 (magnetic recording pattern 2a ) was slightly oxidized, nitrided and halogenated, and the oxides, nitrides and halides were found to deteriorate the electromagnetic conversion characteristics of the magnetic recording medium.
  • the release layer 3 is reduced and removed using a reducing gas substantially free of oxygen, nitrogen, and halogen, and the mask layer 4 and the resist layer 5 are formed on the magnetic layer 2 together with the release layer 3. It is intended to be removed (lifted off). Thereby, oxidation, nitridation, and halogenation of the surface of the magnetic layer 2 can be prevented, and the electromagnetic conversion characteristics of the magnetic recording medium can be improved.
  • a substance that can be reduced and removed is used for the release layer 3, and the removal of the mask layer 4 and the resist layer 5 has reducibility for the release layer 3, while oxidizing, nitriding, and halogenating the magnetic layer 2.
  • the reducing gas that substantially does not contain oxygen, nitrogen, or halogen for example, a gas containing hydrogen or the like can be used. More specifically, the hydrogen content is 60% by volume or more, more preferably 80% by volume or more, and the total content of oxygen, nitrogen and halogen is 15% by volume or less, more preferably 10% by volume or less. Gas can be used.
  • the surface of the magnetic layer 2 is irradiated with an inert gas such as Ar, and the surface layer of the magnetic layer 2 is removed by etching in the range of 1 to 2 nm. Is preferred.
  • an inert gas such as Ar
  • the portion having the lowered magnetic properties can be removed, and the effects of the present invention can be further improved.
  • a protective layer 6 covering the surface from which the mask layer 4 and the resist layer 5 have been removed is formed.
  • a method of forming a DLC (Diamond Like Carbon) thin film using P-CVD or the like is used, but the method is not necessarily limited to such a method.
  • the protective layer 6 is formed with a thickness sufficient to be embedded in the portion from which the magnetic layer 2 has been removed.
  • a lubricant film (not shown) is formed by applying a lubricant on the protective layer 6.
  • the lubricant used for the lubricating film include a fluorine-based lubricant, a hydrocarbon-based lubricant, and a mixture thereof, and the lubricating film is usually formed with a thickness of 1 to 4 nm.
  • the magnetic recording medium can be manufactured through the above steps.
  • the release layer 3 is reduced and removed using a reducing gas that does not substantially contain oxygen, nitrogen, or halogen, thereby removing the release layer 3.
  • the mask layer 4 and the resist layer 5 are removed from above the magnetic layer 2, the surface of the magnetic layer 2 is not oxidized, nitrided, or halogenated, and as a result, a magnetic recording medium having excellent electromagnetic characteristics can be obtained. It is possible to manufacture. Further, in the magnetic recording / reproducing apparatus provided with such a magnetic recording medium having excellent electromagnetic conversion characteristics, it is possible to further improve the recording density.
  • the method of manufacturing the magnetic recording medium includes a step of forming a magnetic layer 2 on at least one surface of a nonmagnetic substrate 1 as shown in FIGS. 2 (a) to 2 (g), for example.
  • a step of forming a release layer 3 on the magnetic layer, a step of forming a mask layer 4 on the release layer 3, a step of forming a resist layer 5 on the mask layer 4, and a surface of the resist layer 5 The mask layer 4 and the release layer 3 of the magnetic layer 2 are covered with the step of patterning into a shape corresponding to the magnetic recording pattern, the step of patterning the mask layer 4 and the release layer 3 using the patterned resist layer 5.
  • a step of partially modifying the non-existing portion a step of removing the mask layer 4 and the release layer 3 from the magnetic layer 2, a step of forming the protective layer 6 thereon, and a lubrication on the protective layer 6 Forming a film (not shown).
  • FIGS. 2A to 2D are basically the same as the steps shown in FIGS. 1A to 1D. Therefore, the description of the steps shown in FIGS. 2A to 2D will be omitted.
  • the resist layer 5, the mask layer 4, and the release layer 3 among the magnetic layers 2 under the mask layer 3 are formed using, for example, reactive plasma or reactive ions.
  • the portions that are not covered are partially modified to form magnetically separated magnetic recording patterns 2b between the modified portions 8.
  • the magnetic recording pattern 2b is separated by a nonmagnetic region 7 which is preferably non-magnetic, with a part of the magnetic properties of the magnetic layer 2 modified.
  • a nonmagnetic region 7 which is preferably non-magnetic, with a part of the magnetic properties of the magnetic layer 2 modified.
  • the modification of the magnetic layer 2 for forming the magnetic recording pattern 2b refers to partially changing the coercive force, the residual magnetization, etc. of the magnetic layer 2 in order to pattern the magnetic layer 2.
  • the change refers to lowering the coercive force and lowering the remanent magnetization.
  • the amount of magnetization of the magnetic layer 2 exposed to reactive plasma or reactive ions is 75% or less of the initial (untreated), more preferably 50% or less, and the coercive force is the initial value. It is preferable to adopt a method of 50% or less, more preferably 20% or less.
  • the magnetic layer 2 is not exposed by exposing the magnetic layer 2 already formed to reactive plasma or reactive ions at a location (the modified portion 8) that separates the magnetic recording track and the servo signal pattern portion. It can also be realized by crystallizing. That is, the modification of the magnetic characteristics of the magnetic layer 2 in the present invention includes realization by modifying the crystal structure of the magnetic layer 2.
  • making the magnetic layer 2 amorphous means that the atomic arrangement of the magnetic layer 2 is in an irregular atomic arrangement having no long-range order, and more specifically, less than 2 nm. This means that the microcrystal grains are arranged at random.
  • this atomic arrangement state is confirmed by an analysis method, a peak representing a crystal plane is not recognized by X-ray diffraction or electron beam diffraction, and only a halo is recognized.
  • reactive plasma examples include inductively coupled plasma (ICP) and reactive ion plasma (RIE).
  • reactive ions examples include reactive ions present in the inductively coupled plasma and reactive ion plasma described above.
  • inductively coupled plasma examples include high-temperature plasma obtained by applying high voltage to a gas and generating Joule heat due to eddy current in the plasma by a high-frequency variable magnetic field.
  • Inductively coupled plasma has a high electron density, and can improve the magnetic properties with high efficiency in a magnetic film having a large area, compared to the case where a discrete track medium is manufactured using a conventional ion beam.
  • the reactive ion plasma is a highly reactive plasma in which a reactive gas such as O 2 , SF 6 , CHF 3 , CF 4 , or CCl 4 is added to the plasma.
  • a reactive gas such as O 2 , SF 6 , CHF 3 , CF 4 , or CCl 4 is added to the plasma.
  • the magnetic layer 2 is modified by exposing the magnetic layer 2 to a reactive plasma. This modification is performed by a reaction between a magnetic metal constituting the magnetic layer 2 and atoms or ions in the reactive plasma. It is preferable to realize.
  • the reaction means that atoms in the reactive plasma enter the magnetic metal, change the crystal structure of the magnetic metal, change the composition of the magnetic metal, oxidize the magnetic metal, Examples include nitriding, silicidation of magnetic metal, and the like.
  • oxidize the magnetic layer 2 by containing oxygen atoms as reactive plasma and reacting the magnetic metal constituting the magnetic layer 2 with oxygen atoms in the reactive plasma.
  • oxygen atoms as reactive plasma
  • halogen atoms in the reactive plasma.
  • F atom an F atom
  • the halogen atom may be added to the reactive plasma together with the oxygen atom, or may be added to the reactive plasma without using the oxygen atom.
  • oxygen atoms or the like by adding oxygen atoms or the like to the reactive plasma, the magnetic metal constituting the magnetic layer 2 reacts with oxygen atoms or the like, so that the magnetic characteristics of the magnetic layer 2 can be modified. At this time, the reactivity can be further increased by adding halogen atoms to the reactive plasma.
  • halogen atoms can react with the magnetic alloy to improve the magnetic properties of the magnetic layer 2. Although the details of this reason are not clear, the halogen atoms in the reactive plasma etch foreign matter formed on the surface of the magnetic layer 2, thereby cleaning the surface of the magnetic layer 2 and reacting the magnetic layer 2. It is considered that the property is increased.
  • the cleaned magnetic layer surface and halogen atoms react with high efficiency. It is particularly preferable to use an F atom as the halogen atom having such an effect.
  • the release layer 2 is reduced and removed by using a reducing gas substantially free of oxygen, nitrogen, and halogen, so that the mask together with the release layer 2 is masked. Since the layer 4 and the resist layer 5 are removed from above the magnetic layer 2, the surface of the magnetic layer 2 is not oxidized, nitrided or halogenated, and as a result, a magnetic recording medium having excellent electromagnetic conversion characteristics is manufactured. It is possible. Further, in the magnetic recording / reproducing apparatus provided with such a magnetic recording medium having excellent electromagnetic conversion characteristics, it is possible to further improve the recording density.
  • this invention is not necessarily limited to the thing of the said embodiment, A various change can be added in the range which does not deviate from the meaning of this invention.
  • the concave / convex pattern having a shape corresponding to the magnetic recording pattern 2a can be transferred to the mask layer 4 using a stamp, it is not necessary to provide the resist layer 5 on the mask layer 4.
  • the magnetic recording pattern 2a (which is magnetically separated into the magnetic layer 2 using the patterned mask layer 4). 2b) may be formed.
  • a method of forming a magnetic recording pattern on the magnetic layer 2 a portion of the magnetic layer 2 that is not covered with the release layer 3, the mask layer 4 and the resist layer 5 is partially removed, It is also possible to adopt a method of partially modifying the magnetic characteristics of the recess after forming the recess in the magnetic layer 2.
  • the object of the present invention can be achieved even if the magnetic layer 2 is not separated at the bottom of the magnetic layer 2. Included in the concept of magnetically separated magnetic recording patterns.
  • the present invention can be widely applied to a magnetic recording medium having a magnetically separated magnetic recording pattern.
  • the magnetic recording pattern is 1 bit. Examples thereof include so-called patterned media arranged with a certain regularity, media with magnetic recording patterns arranged in a track shape, and other magnetic recording media including servo signal patterns.
  • the present invention is preferably applied to a so-called discrete type magnetic recording medium in which magnetically separated magnetic recording patterns are magnetic recording tracks and servo signal patterns, from the viewpoint of simplicity in manufacturing.
  • a magnetic recording / reproducing apparatus to which the present invention is applied includes, for example, as shown in FIG. 3, a magnetic recording medium 30 manufactured by the manufacturing method of the present invention, a rotational drive unit 51 that rotationally drives the magnetic recording medium 30, and a magnetic A magnetic head 52 that performs a recording operation and a reproducing operation on the recording medium 30, a head drive unit 53 that moves the magnetic head 52 in the radial direction of the magnetic recording medium 30, a signal input to the magnetic head 52, and an output from the magnetic head 52 And a recording / reproducing signal processing system 54 for reproducing the signal.
  • this magnetic recording / reproducing apparatus by using the discrete track type magnetic recording medium 30, it is possible to eliminate writing blur when performing magnetic recording on the magnetic recording medium 30 and to obtain a high surface recording density. That is, by using the magnetic recording medium 30, a magnetic recording / reproducing apparatus having a high recording density can be configured.
  • the reproducing head width is made narrower than the recording head width in order to eliminate the influence of the magnetization transition region at the track edge portion. What was supported can be operated with both of them approximately the same width. As a result, sufficient reproduction output and high SNR can be obtained.
  • the reproducing unit of the magnetic head 52 by configuring the reproducing unit of the magnetic head 52 with a GMR head or a TMR head, a sufficient signal intensity can be obtained even at a high recording density, and a magnetic recording / reproducing apparatus having a high recording density can be realized. it can. Further, when the flying height of the magnetic head 52 is within the range of 0.005 ⁇ m to 0.020 ⁇ m and the flying height is lower than the conventional height, the output is improved and a high device SNR is obtained, and the large capacity and the high reliability are obtained.
  • the magnetic recording / reproducing apparatus can be provided.
  • the recording density can be further improved.
  • the track density is 100 k tracks / inch or more
  • the linear recording density is 1000 k bits / inch or more
  • the recording density is 100 G bits or more per square inch.
  • a sufficient SNR can also be obtained when recording / reproducing.
  • Example 1 In Example 1, first, the vacuum chamber in which the glass substrate for HD was set was evacuated to 1.0 ⁇ 10 ⁇ 5 Pa or less in advance.
  • the glass substrate used here is composed of Li 2 Si 2 O 5 , Al 2 O 3 —K 2 O, Al 2 O 3 —K 2 O, MgO—P 2 O 5 , Sb 2 O 3 —ZnO.
  • the crystallized glass is made of a material having an outer diameter of 65 mm, an inner diameter of 20 mm, and an average surface roughness (Ra) of 2 angstroms.
  • this glass substrate was subjected to a DC sputtering method using a FeCoB film with a thickness of 60 nm as a soft magnetic layer, a Ru film with a thickness of 10 nm as an intermediate layer, and a 70 Co-5Cr-15Pt— with a thickness of 15 nm as a recording magnetic layer.
  • a 10SiO 2 alloy film, a 70Co-5Cr-15Pt alloy film with a thickness of 14 nm, a novolak resin film with a thickness of 50 nm as a release layer, and a carbon film with a thickness of 20 nm as a mask layer were laminated in this order.
  • a resist was applied thereon by a spin coating method to form a resist layer having a layer thickness of 100 nm.
  • SOG was used as the resist.
  • UV light having a wavelength of 250 nm is applied to the resist layer in a state where the stamp is pressed against the resist layer at a pressure of 1 MPa (about 8.8 kgf / cm 2 ).
  • the resist layer was cured by irradiating from the top of a glass stamp having a transmittance of 95% or more for 10 seconds. Thereafter, the stamp was separated from the resist layer, and an uneven pattern corresponding to the magnetic recording pattern was transferred to the resist layer.
  • the concavo-convex pattern transferred to the resist layer corresponds to a magnetic recording pattern of 271 k tracks / inch, with the convex portion having a circumferential shape having a width of 120 nm and the concave portion having a circumferential shape having a width of 60 nm.
  • the thickness was 80 nm, and the depth of the concave portion of the resist layer was about 5 nm.
  • the angle of the recess with respect to the substrate surface was approximately 90 degrees.
  • the dry etching conditions were as follows: hydrogen gas was 40 sccm, pressure was 0.3 Pa, high-frequency plasma power was 300 W, DC bias was 30 W, and etching time was 30 seconds.
  • portions of the recording magnetic layer not covered with the release layer, mask layer, and resist layer were removed by ion etching.
  • the ion etching conditions were as follows: nitrogen gas was 10 sccm, pressure was 0.1 Pa, high-frequency plasma power was 300 W, DC bias was 30 W, and etching time was 30 seconds. At this time, the depth of the recess formed in the recording magnetic layer was about 10 nm. In addition, in the concave portion of the recording magnetic layer, a region having a depth of about 5 nm from the bottom surface was made nonmagnetic by ion implantation of nitrogen atoms.
  • the release layer was reduced and removed, and the release layer was removed from the magnetic layer together with the resist layer and the mask layer.
  • the reduction conditions were hydrogen gas of 40 sccm, pressure of 0.3 Pa, high-frequency plasma power of 300 W, DC bias of 30 W, and exposure time of 30 seconds.
  • the surface of the recording magnetic layer was etched in the range of about 1 to 2 nm by an ion milling apparatus with an argon gas of 10 sccm, a pressure of 0.5 Pa, and an etching time of 5 seconds.
  • a carbon protective film having a thickness of 5 nm was formed on the surface of the recording magnetic layer by a CVD method, and then a fluorine-based lubricant was applied to 2.0 nm to produce a magnetic recording medium.
  • the electromagnetic conversion characteristics of the magnetic recording medium manufactured by the above method were measured.
  • the evaluation of electromagnetic conversion characteristics was performed using a spin stand. At this time, as the evaluation head, a perpendicular recording head was used for recording and a TuMR head was used for reading. Then, the SNR when a 750 kFCI signal was recorded was measured. As a result, in Example 1, the SNR was 16.2 dB.
  • Example 2 SOG was used for the mask layer, and no resist layer was provided. That is, SOG was applied by spin coating on a novolac resin film to be a release layer to form a mask layer having a layer thickness of 100 nm. Then, using a glass stamp having a positive pattern of the magnetic recording pattern, a 150 W heat ray was irradiated for 10 seconds with this stamp pressed against the mask layer at a pressure of 1 MPa (about 8.8 kgf / cm 2 ). The mask layer was cured. Thereafter, the stamp was separated from the mask layer, and an uneven pattern corresponding to the magnetic recording pattern was transferred to the mask layer.
  • the concave portion of the mask layer was removed by dry etching.
  • the dry etching conditions were argon gas of 40 sccm, pressure of 0.3 Pa, high frequency plasma power of 300 W, DC bias of 30 W, and etching time of 15 seconds.
  • the ion etching conditions were as follows: nitrogen gas was 10 sccm, pressure was 0.1 Pa, high-frequency plasma power was 150 W, DC bias was 30 W, and etching time was 50 seconds.
  • the dry etching conditions were as follows: hydrogen gas was 40 sccm, pressure was 0.3 Pa, high-frequency plasma power was 300 W, DC bias was 30 W, and etching time was 30 seconds.
  • Example 2 a magnetic recording medium was manufactured under the same conditions as in Example 1. As a result, in Example 2, the SNR was 16.3 dB.
  • Comparative Example 1 In Comparative Example 1, the resist layer and the mask layer were removed by dry etching using oxygen plasma.
  • the dry etching conditions were oxygen gas of 40 sccm, pressure of 0.3 Pa, high-frequency plasma power of 300 W, DC bias of 30 W, and etching time of 20 seconds.
  • Comparative Example 2 In Comparative Example 2, the resist layer and the mask layer were removed by dry etching using nitrogen plasma.
  • the dry etching conditions were as follows: nitrogen gas was 40 sccm, pressure was 0.3 Pa, high-frequency plasma power was 300 W, DC bias was 30 W, and etching time was 25 seconds.
  • Example 2 a magnetic recording medium was manufactured under the same conditions as in Example 1. As a result, in Comparative Example 2, the SNR was 15.7 dB.
  • Comparative Example 3 In Comparative Example 3, the resist layer and the mask layer were removed by dry etching using halogen plasma.
  • the dry etching conditions were CF 4 gas of 40 sccm, pressure of 0.3 Pa, high-frequency plasma power of 300 W, DC bias of 30 W, and etching time of 15 seconds.

Abstract

Provided is a magnetic recording medium manufacturing method whereby excellent electromagnetic conversion characteristics can be obtained. Said method includes: a step in which a magnetic layer (2) is formed on at least one surface of a nonmagnetic substrate (1); a step in which a release layer (3) is formed on top of the magnetic layer; a step in which a mask layer (4) is formed on top of the release layer (3); a step in which a resist layer (5) is formed on top of the mask layer (4); a step in which a pattern corresponding to a magnetic recording pattern is formed in the surface of the resist layer (5); a step in which the patterned resist layer (5) is used to pattern the mask layer (4) and the release layer (3); a step in which the parts of the magnetic layer (2) not covered by the mask layer (4) and the release layer (3) are removed; and a step in which a reducing gas that contains essentially no oxygen, nitrogen, or halogens is used to reduce the release layer (3), thereby removing both the release layer (3) and the mask layer (4) from the magnetic layer (2).

Description

磁気記録媒体の製造方法及び磁気記録再生装置Magnetic recording medium manufacturing method and magnetic recording / reproducing apparatus
　本発明は、ハードディスク装置（ＨＤＤ）等に用いられる磁気記録媒体の製造方法及び磁気記録再生装置に関するものである。
  本願は、２０１０年１月１８日に、日本に出願された特願２０１０－００８０２１号に基づき優先権を主張し、その内容をここに援用する。 The present invention relates to a method for manufacturing a magnetic recording medium used in a hard disk drive (HDD) and the like, and a magnetic recording / reproducing apparatus.
This application claims priority on January 18, 2010 based on Japanese Patent Application No. 2010-008021 filed in Japan, the contents of which are incorporated herein by reference.
　近年、磁気ディスク装置、フレキシブルディスク装置、磁気テープ装置等の磁気記録装置の適用範囲は著しく増大され、その重要性が増すと共に、これらの装置に用いられる磁気記録媒体について、その記録密度の著しい向上が図られつつある。特に、ＭＲヘッドやＰＲＭＬ技術の導入以来、面記録密度の上昇は更に激しさを増し、近年ではＧＭＲヘッドやＴＭＲヘッドなども導入されて、１年に１．５倍ものペースで増加を続けている。 In recent years, the application range of magnetic recording devices such as magnetic disk devices, flexible disk devices, and magnetic tape devices has been remarkably increased, and the importance has increased, and the recording density of magnetic recording media used in these devices has been significantly improved. Is being planned. In particular, since the introduction of MR heads and PRML technology, the increase in surface recording density has become even more intense. In recent years, GMR heads and TMR heads have also been introduced and have continued to increase at a rate of 1.5 times a year. Yes.
　これらの磁気記録媒体については、今後更に高記録密度を達成することが要求されている。このため、磁性層の高保磁力化、高信号対雑音比(ＳＮＲ)、及び高分解能を達成することが要求されている。また、近年では線記録密度の向上と同時にトラック密度の増加によって面記録密度を上昇させようとする努力も続けられている。 These magnetic recording media are required to achieve higher recording density in the future. For this reason, it is required to achieve a high coercivity of the magnetic layer, a high signal-to-noise ratio (SNR), and high resolution. In recent years, efforts have been made to increase the surface recording density by increasing the track density as well as improving the linear recording density.
　最新の磁気記録装置においては、トラック密度２５０ｋＴＰＩにも達している。しかしながら、トラック密度を上げていくと、隣接するトラック間の磁気記録情報が互いに干渉し合い、その境界領域の磁化遷移領域がノイズ源となりＳＮＲを損なうという問題が生じ易くなっており、このことはそのままビット・エラー・レートの悪化につながるため、記録密度の向上に対して障害となっている。 In the latest magnetic recording device, the track density has reached 250 kTPI. However, as the track density is increased, magnetic recording information between adjacent tracks interferes with each other, and the problem that the magnetization transition region in the boundary region becomes a noise source and the SNR is easily lost. This leads to a deterioration of the bit error rate, which is an obstacle to improvement of the recording density.
　面記録密度を上昇させるためには、磁気記録媒体上の各記録ビットのサイズをより微細なものとし、各記録ビットに可能な限り大きな飽和磁化と磁性膜厚を確保する必要がある。その一方で、記録ビットを微細化していくと、１ビット当たりの磁化最小体積が小さくなり、熱揺らぎによる磁化反転で記録データが消失するという問題が生じてしまう。 In order to increase the surface recording density, it is necessary to make the size of each recording bit on the magnetic recording medium finer and ensure as much saturation magnetization and magnetic film thickness as possible for each recording bit. On the other hand, when the recording bit is miniaturized, the minimum magnetization volume per bit is reduced, and there arises a problem that the recording data is lost due to magnetization reversal due to thermal fluctuation.
　また、トラック密度を上げていくと、トラック間距離が近づくために、磁気記録装置では極めて高精度のトラックサーボ技術が要求されると同時に、記録を幅広く実行し、再生は隣接トラックからの影響をできるだけ排除するために記録時よりも狭く実行する方法が一般的に用いられている。しかしながら、この方法ではトラック間の影響を最小限に抑えることができる反面、再生出力を十分得ることが困難であり、その結果十分なＳＮＲを確保することが難しいという問題がある。 In addition, as the track density increases, the distance between tracks becomes closer, so the magnetic recording device requires extremely accurate track servo technology.At the same time, recording is performed widely, and playback is affected by adjacent tracks. In order to eliminate as much as possible, a method of executing narrower than the recording is generally used. However, this method can minimize the influence between tracks, but has a problem that it is difficult to obtain a sufficient reproduction output, and as a result, it is difficult to ensure a sufficient SNR.
　このような熱揺らぎの問題やＳＮＲの確保、十分な出力の確保を達成する方法の一つとして、記録媒体表面にトラックに沿った凹凸を形成し、記録トラック同士を物理的に分離することによってトラック密度を上げようとする試みがなされている。このような技術は、一般にディスクリートトラック法と呼ばれており、それによって製造された磁気記録媒体のことをディスクリートトラック媒体と呼んでいる。また、同一トラック内のデータ領域を更に分割した、いわゆるパターンドメディアを製造しようとする試みもある。 As one of the methods for achieving such problems of thermal fluctuation, ensuring SNR, and ensuring sufficient output, by forming irregularities along the tracks on the recording medium surface and physically separating the recording tracks from each other Attempts have been made to increase track density. Such a technique is generally called a discrete track method, and a magnetic recording medium manufactured by the technique is called a discrete track medium. There is also an attempt to manufacture a so-called patterned medium in which the data area in the same track is further divided.
　ディスクリートトラック媒体の一例として、表面に凹凸パターンを形成した非磁性基板を用い、この上に磁性層を形成して、物理的に分離した磁気記録トラック及びサーボ信号パターンを形成してなる磁気記録媒体が知られている（例えば、特許文献１を参照。）。 As an example of a discrete track medium, a magnetic recording medium using a nonmagnetic substrate having a concavo-convex pattern formed on a surface, forming a magnetic layer thereon, and forming physically separated magnetic recording tracks and servo signal patterns Is known (see, for example, Patent Document 1).
　この磁気記録媒体は、表面に複数の凹凸のある基板の表面に軟磁性層を介して強磁性層が形成されており、その表面に保護膜を形成したものである。この磁気記録媒体では、凸部領域に周囲と物理的に分断された磁気記録領域が形成されている。 In this magnetic recording medium, a ferromagnetic layer is formed on the surface of a substrate having a plurality of irregularities on the surface via a soft magnetic layer, and a protective film is formed on the surface. In this magnetic recording medium, a magnetic recording area physically separated from the periphery is formed in the convex area.
　この磁気記録媒体によれば、軟磁性層での磁壁発生を抑制できるため熱揺らぎの影響が出にくく、隣接する信号間の干渉もないので、ノイズの少ない高密度磁気記録媒体を形成できるとされている。 According to this magnetic recording medium, the occurrence of a domain wall in the soft magnetic layer can be suppressed, so that the influence of thermal fluctuation is difficult to occur, and there is no interference between adjacent signals, so that a high-density magnetic recording medium with less noise can be formed. ing.
　ディスクリートトラック法には、何層かの薄膜からなる磁気記録媒体を形成した後にトラックを形成する方法と、予め基板表面に直接、或いはトラック形成のための薄膜層に凹凸パターンを形成した後に、磁気記録媒体の薄膜形成を行う方法がある（例えば、特許文献２，３を参照。）。 The discrete track method includes a method of forming a track after forming a magnetic recording medium consisting of several thin films, and a magnetic pattern after forming a concavo-convex pattern directly on the substrate surface in advance or on a thin film layer for track formation. There is a method of forming a thin film of a recording medium (see, for example, Patent Documents 2 and 3).
　このうち、前者の方法は、磁気層加工型と呼ばれるものである。しかしながら、この方法の場合、媒体形成後に表面に対する物理的な加工が実施されるため、媒体が製造工程において汚染されやすく、かつ製造工程が非常に複雑となるといった欠点がある。一方、後者の方法は、エンボス加工型と呼ばれるものである。しかしながら、この方法の場合、製造工程中に媒体が汚染されにくいものの、基板に形成された凹凸形状がその上に成膜された膜にも引き継がれることになるため、媒体上を浮上しながら記録再生を行う記録再生ヘッドの浮上姿勢や、浮上高さが安定しなくなるといった問題がある。 Of these, the former method is called a magnetic layer processing type. However, in this method, since the surface is physically processed after the medium is formed, there is a disadvantage that the medium is easily contaminated in the manufacturing process and the manufacturing process becomes very complicated. On the other hand, the latter method is called an embossing die. However, in this method, although the medium is not easily contaminated during the manufacturing process, the uneven shape formed on the substrate is inherited by the film formed thereon, so that recording is performed while floating on the medium. There is a problem that the flying posture of the recording / reproducing head for performing reproduction and the flying height become unstable.
　また、ディスクリートトラック媒体の磁気トラック間領域を、予め形成した磁性層に窒素、酸素等のイオンを注入し、または、レーザを照射することにより、その部分の磁気的な特性を変化させて形成する方法が開示されている（例えば、特許文献４を参照。）。 Also, the magnetic track area of the discrete track medium is formed by injecting ions such as nitrogen and oxygen into a previously formed magnetic layer or by irradiating a laser to change the magnetic characteristics of the portion. A method is disclosed (see, for example, Patent Document 4).
特開２００４－１６４６９２号公報JP 2004-164692 A 特開２００４－１７８７９３号公報JP 2004-178793 A 特開２００４－１７８７９４号公報JP 2004-178794 A 特開平５－２０５２５７号公報Japanese Patent Laid-Open No. 5-205257
　ところで、上述した特許文献４に記載の方法では、磁性層に部分的にイオンを注入し、その部分の磁気特性を変えることによって、磁性層に磁気的に分離された磁気記録パターンが形成される。ここで、磁性層に部分的にイオンを注入するためには、磁性層の表面にパターニングしたマスク層を設ける必要がある。また、マスク層をパターニングするために、このマスク層の上にレジスト層を設ける場合もある。そして、磁性層にイオンを注入した後に、これらマスク層やレジスト層が除去される。 By the way, in the method described in Patent Document 4 described above, a magnetic recording pattern magnetically separated is formed in the magnetic layer by partially implanting ions into the magnetic layer and changing the magnetic characteristics of the portion. . Here, in order to partially inject ions into the magnetic layer, it is necessary to provide a patterned mask layer on the surface of the magnetic layer. In some cases, a resist layer is provided on the mask layer in order to pattern the mask layer. Then, after implanting ions into the magnetic layer, these mask layer and resist layer are removed.
　レジスト層及びマスク層の除去には、ドライエッチングが用いられる。ドライエッチングとは、レジスト層やマスク層を構成する固体物質とガスとを反応させて固体物質をガス化し除去する方法である。例えば、Ｃ系の固体物質の場合、酸素ガスや窒素ガスを用いてこれをＣＯ系ガスやＣＮ系ガスとして除去する方法、ＳｉＯ２系の固体物質の場合、ＣＦ４系ガスを用いてこれをハロゲン化ガスとして除去する方法などが知られている。 Dry etching is used to remove the resist layer and the mask layer. Dry etching is a method in which a solid substance constituting a resist layer or a mask layer is reacted with a gas to gasify and remove the solid substance. For example, in the case of a C-based solid material, a method of removing it as a CO-based gas or a CN-based gas using oxygen gas or nitrogen gas, and in the case of a SiO 2 -based solid material, this is performed using CF 4 -based gas. A method of removing it as a halogenated gas is known.
　しかしながら、このような酸素や窒素、ハロゲンなどを用いたドライエッチングによりレジスト層やマスク層を除去すると、磁性層の表面が酸化、窒化、ハロゲン化されることによって、その酸化物や窒化物、ハロゲン化物などが磁気記録媒体の電磁変換特性を低下させることが、本発明者の検討により明らかになった。 However, when the resist layer and the mask layer are removed by dry etching using oxygen, nitrogen, halogen, etc., the surface of the magnetic layer is oxidized, nitrided, or halogenated, so that the oxide, nitride, halogen It has been clarified by the inventor's examination that a compound or the like deteriorates the electromagnetic conversion characteristics of a magnetic recording medium.
　本発明は、上記課題を解決するために提案されたものであり、優れた電磁変換特性が得られる磁気記録媒体の製造方法、並びに、そのような製造方法により製造された磁気記録媒体を用いた磁気記録再生装置を提供することを目的とする。 The present invention has been proposed in order to solve the above-described problems, and uses a method for manufacturing a magnetic recording medium capable of obtaining excellent electromagnetic conversion characteristics, and a magnetic recording medium manufactured by such a manufacturing method. An object of the present invention is to provide a magnetic recording / reproducing apparatus.
　本発明は、以下の手段を提供する。
（１）　磁気的に分離された磁気記録パターンを有する磁気記録媒体の製造方法であって、
　非磁性基板の少なくとも一方の面上に磁性層を形成する工程と、
　前記磁性層の上に剥離層を形成する工程と、
　前記剥離層の上にマスク層を形成する工程と、
　前記マスク層及び剥離層を前記磁気記録パターンに対応した形状にパターニングする工程と、
　前記磁性層の前記マスク層及び剥離層で覆われていない箇所を部分的に改質又は除去する工程と、
　前記マスク層及び剥離層を除去する工程とを含み、
　前記マスク層及び剥離層を除去する際に、実質的に酸素、窒素、ハロゲンを含まない還元性のガスを用いて前記剥離層を還元除去することによって、この剥離層と共に前記マスク層を前記磁性層の上から除去することを特徴とする磁気記録媒体の製造方法。
（２）　前記マスク層をパターニングする前に、当該マスク層の上に前記磁気記録パターンに対応した形状にパターニングされたレジスト層を形成する工程を含み、
　前記レジスト層を用いて前記マスク層を前記磁気記録パターンに対応した形状にパターニングし、前記パターニングされたマスク層を用いて前記磁性層を部分的に改質又は除去した後、前記還元性のガスを用いて前記剥離層を還元除去することによって、この剥離層と共に前記マスク層及びレジスト層を前記磁性層の上から除去することを特徴とする（１）に記載の磁気記録媒体の製造方法。
（３）　前記剥離層として、ノボラック樹脂を用いることを特徴とする（１）又は（２）に記載の磁気記録媒体の製造方法。
（４）　前記還元性のガスとして、水素を用いることを特徴とする（１）～（３）の何れか一項に記載の磁気記録媒体の製造方法。
（５）　（１）～（４）の何れか一項に記載の製造方法により製造された磁気記録媒体と、
　前記磁気記録媒体を記録方向に駆動する媒体駆動部と、
　前記磁気記録媒体に対する記録動作と再生動作とを行う磁気ヘッドと、
　前記磁気ヘッドを磁気記録媒体に対して相対移動させるヘッド移動手段と、
　前記磁気ヘッドへの信号入力と前記磁気ヘッドから出力信号の再生とを行うための記録再生信号処理手段とを備えることを特徴とする磁気記録再生装置。 The present invention provides the following means.
(1) A method of manufacturing a magnetic recording medium having magnetically separated magnetic recording patterns,
Forming a magnetic layer on at least one surface of the nonmagnetic substrate;
Forming a release layer on the magnetic layer;
Forming a mask layer on the release layer;
Patterning the mask layer and the release layer into a shape corresponding to the magnetic recording pattern;
A step of partially modifying or removing a portion of the magnetic layer that is not covered with the mask layer and the release layer;
Removing the mask layer and the release layer,
When removing the mask layer and the release layer, the release layer is reduced and removed using a reducing gas substantially free of oxygen, nitrogen, and halogen, so that the mask layer and the release layer are magnetically removed. A method of manufacturing a magnetic recording medium, comprising removing the layer from above.
(2) before patterning the mask layer, including a step of forming a resist layer patterned into a shape corresponding to the magnetic recording pattern on the mask layer;
After patterning the mask layer into a shape corresponding to the magnetic recording pattern using the resist layer and partially modifying or removing the magnetic layer using the patterned mask layer, the reducing gas is used. The method for producing a magnetic recording medium according to (1), characterized in that the mask layer and the resist layer are removed together with the release layer from the top of the magnetic layer by reducing and removing the release layer using an adhesive.
(3) The method for producing a magnetic recording medium according to (1) or (2), wherein a novolac resin is used as the release layer.
(4) The method for manufacturing a magnetic recording medium according to any one of (1) to (3), wherein hydrogen is used as the reducing gas.
(5) a magnetic recording medium manufactured by the manufacturing method according to any one of (1) to (4);
A medium driving unit for driving the magnetic recording medium in a recording direction;
A magnetic head for performing a recording operation and a reproducing operation on the magnetic recording medium;
Head moving means for moving the magnetic head relative to a magnetic recording medium;
A magnetic recording / reproducing apparatus comprising: a recording / reproducing signal processing means for inputting a signal to the magnetic head and reproducing an output signal from the magnetic head.
　以上のように、本発明では、実質的に酸素、窒素、ハロゲンを含まない還元性のガスを用いて剥離層を還元除去することによって、この剥離層と共にマスク層を磁性層の上から除去することから、磁性層の表面が酸化、窒化、ハロゲン化されることがなく、その結果、電磁変換特性に優れた磁気記録媒体を製造することが可能となる。また、このような電磁変換特性に優れた磁気記録媒体を備えた磁気記録再生装置では、記録密度の更なる向上を図ることが可能である。 As described above, according to the present invention, the mask layer is removed together with the release layer from the magnetic layer by reducing and removing the release layer using a reducing gas substantially free of oxygen, nitrogen, and halogen. Therefore, the surface of the magnetic layer is not oxidized, nitrided or halogenated, and as a result, a magnetic recording medium having excellent electromagnetic conversion characteristics can be manufactured. Further, in the magnetic recording / reproducing apparatus provided with such a magnetic recording medium having excellent electromagnetic conversion characteristics, it is possible to further improve the recording density.
図１は、本発明を適用した磁気記録媒体の製造方法の一例を説明するための断面図である。FIG. 1 is a cross-sectional view for explaining an example of a method of manufacturing a magnetic recording medium to which the present invention is applied. 図２は、本発明を適用した磁気記録媒体の製造方法の他例を説明するための断面図である。FIG. 2 is a cross-sectional view for explaining another example of a method of manufacturing a magnetic recording medium to which the present invention is applied. 図３は、磁気記録再生装置の一構成例を示す斜視図である。FIG. 3 is a perspective view showing a configuration example of the magnetic recording / reproducing apparatus.
　以下、本発明の実施の形態について、図面を参照して詳細に説明する。
　なお、以下の説明で用いる図面は、特徴をわかりやすくするために、便宜上特徴となる部分を拡大して示している場合があり、各構成要素の寸法比率などが実際と同じであるとは限らない。 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
In addition, in the drawings used in the following description, in order to make the features easy to understand, there are cases where the portions that become the features are enlarged for the sake of convenience, and the dimensional ratios of the respective components are not always the same as the actual ones. Absent.
（磁気記録媒体の製造方法）
　先ず、本発明を適用した磁気記録媒体の製造方法の一例について説明する。なお、以下の説明では、磁気記録媒体の片面のみを図示するものとするが、磁気記録媒体の両面について同様の構成とすることが可能である。 (Method of manufacturing magnetic recording medium)
First, an example of a method for manufacturing a magnetic recording medium to which the present invention is applied will be described. In the following description, only one side of the magnetic recording medium is illustrated, but the same configuration can be applied to both sides of the magnetic recording medium.
　本発明を適用した磁気記録媒体の製造方法は、磁気的に分離された磁気記録パターンを有する磁気記録媒体を製造する際に、例えば図１（ａ）～（ｇ）に示すように、非磁性基板１の少なくとも一方の面上に磁性層２を形成する工程と、磁性層の上に剥離層３を形成する工程と、剥離層３の上にマスク層４を形成する工程と、マスク層４の上にレジスト層５を形成する工程と、レジスト層５の表面を磁気記録パターンに対応した形状にパターニングする工程と、パターニングされたレジスト層５を用いてマスク層４及び剥離層３をパターニングする工程と、磁性層２のマスク層４及び剥離層３で覆われていない箇所を部分的に除去する工程と、マスク層４及び剥離層３を磁性層２の上から除去する工程と、この上に保護層６を形成する工程と、保護層６の上に潤滑膜を形成する工程（図示せず。）とを含んでいる。 The method of manufacturing a magnetic recording medium to which the present invention is applied is a non-magnetic method as shown in FIGS. 1A to 1G, for example, when manufacturing a magnetic recording medium having a magnetically separated magnetic recording pattern. A step of forming a magnetic layer 2 on at least one surface of the substrate 1, a step of forming a release layer 3 on the magnetic layer, a step of forming a mask layer 4 on the release layer 3, and a mask layer 4 Forming the resist layer 5 on the substrate, patterning the surface of the resist layer 5 into a shape corresponding to the magnetic recording pattern, and patterning the mask layer 4 and the release layer 3 using the patterned resist layer 5. A step of partially removing portions of the magnetic layer 2 that are not covered with the mask layer 4 and the release layer 3, a step of removing the mask layer 4 and the release layer 3 from above the magnetic layer 2, Forming protective layer 6 on the substrate , And a step of forming a lubricating film on the protective layer 6 (not shown.).
　具体的に、このような磁気記録媒体を製造する際は、先ず、図１（ａ）に示すように、非磁性基板１の上に、磁性層２、剥離層３及びマスク層４を順次積層して形成する。 Specifically, when manufacturing such a magnetic recording medium, first, as shown in FIG. 1A, a magnetic layer 2, a release layer 3, and a mask layer 4 are sequentially laminated on a nonmagnetic substrate 1. To form.
　非磁性基板３１としては、例えば、Ａｌ－Ｍｇ合金などのＡｌを主成分としたＡｌ合金基板、ソーダガラスやアルミノシリケート系ガラス、結晶化ガラスなどのガラス基板、シリコン基板、チタン基板、セラミックス基板、樹脂基板等の各種基板を挙げることができるが、その中でも、Ａｌ合金基板や、ガラス基板、シリコン基板を用いることが好ましい。また、非磁性基板３１の平均表面粗さ（Ｒａ）は、１ｎｍ以下であることが好ましく、より好ましくは０．５ｎｍ以下であり、さらに好ましくは０．１ｎｍ以下である。 Examples of the nonmagnetic substrate 31 include an Al alloy substrate mainly composed of Al, such as an Al—Mg alloy, a glass substrate such as soda glass, aluminosilicate glass, or crystallized glass, a silicon substrate, a titanium substrate, a ceramic substrate, Various substrates such as a resin substrate can be mentioned, and among them, an Al alloy substrate, a glass substrate, and a silicon substrate are preferably used. Further, the average surface roughness (Ra) of the nonmagnetic substrate 31 is preferably 1 nm or less, more preferably 0.5 nm or less, and further preferably 0.1 nm or less.
　磁性層２は、面内磁気記録媒体用の面内磁性層でも、垂直磁気記録媒体用の垂直磁性層でもかまわないが、より高い記録密度を実現するためには垂直磁性層が好ましい。また、磁性層２は、主としてＣｏを主成分とする合金から形成することが好ましい。 The magnetic layer 2 may be an in-plane magnetic layer for an in-plane magnetic recording medium or a perpendicular magnetic layer for a perpendicular magnetic recording medium, but a perpendicular magnetic layer is preferable in order to realize a higher recording density. The magnetic layer 2 is preferably formed of an alloy mainly containing Co as a main component.
　例えば、垂直磁気記録媒体用の磁性層２としては、例えば軟磁性のＦｅＣｏ合金（ＦｅＣｏＢ、ＦｅＣｏＳｉＢ、ＦｅＣｏＺｒ、ＦｅＣｏＺｒＢ、ＦｅＣｏＺｒＢＣｕなど）、ＦｅＴａ合金（ＦｅＴａＮ、ＦｅＴａＣなど）、Ｃｏ合金（ＣｏＴａＺｒ、ＣｏＺｒＮＢ、ＣｏＢなど）等からなる軟磁性層と、Ｒｕ等からなる中間層と、６０Ｃｏ－１５Ｃｒ－１５Ｐｔ合金や７０Ｃｏ－５Ｃｒ－１５Ｐｔ－１０ＳｉＯ２合金からなる記録磁性層とを積層したものを利用できる。また、軟磁性層と中間層との間にＰｔ、Ｐｄ、ＮｉＣｒ、ＮｉＦｅＣｒなどからなる配向制御膜を積層してもよい。一方、面内磁気記録媒体用の磁性層２としては、例えば非磁性のＣｒＭｏ下地層と強磁性のＣｏＣｒＰｔＴａ磁性層とを積層したものなどを利用できる。 For example, as the magnetic layer 2 for perpendicular magnetic recording media, for example, soft magnetic FeCo alloys (FeCoB, FeCoSiB, FeCoZr, FeCoZrB, FeCoZrBCu, etc.), FeTa alloys (FeTaN, FeTaC, etc.), Co alloys (CoTaZr, CoZrNB, CoB) Etc.), an intermediate layer made of Ru, etc., and a recording magnetic layer made of 60Co-15Cr-15Pt alloy or 70Co-5Cr-15Pt-10SiO 2 alloy can be used. Further, an orientation control film made of Pt, Pd, NiCr, NiFeCr or the like may be laminated between the soft magnetic layer and the intermediate layer. On the other hand, as the magnetic layer 2 for the in-plane magnetic recording medium, for example, a laminate of a nonmagnetic CrMo underlayer and a ferromagnetic CoCrPtTa magnetic layer can be used.
　記録磁性層の厚みは、３ｎｍ以上２０ｎｍ以下、好ましくは５ｎｍ以上１５ｎｍ以下とし、使用する磁性合金の種類と積層構造に合わせて、十分なヘッド出入力が得られるように形成すればよい。また、記録磁性層は、再生の際に一定以上の出力を得るのにある程度以上の膜厚が必要であり、一方で記録再生特性を表す諸パラメーターは出力の上昇とともに劣化するのが通例であるため、最適な膜厚に設定する必要がある。記録磁性層は、通常はスパッタ法により薄膜として形成する。 The thickness of the recording magnetic layer is 3 nm or more and 20 nm or less, preferably 5 nm or more and 15 nm or less, and may be formed so as to obtain sufficient head input / output according to the type of magnetic alloy used and the laminated structure. In addition, the recording magnetic layer needs to have a film thickness of a certain degree or more in order to obtain an output of a certain level or more during reproduction, while parameters indicating recording / reproduction characteristics usually deteriorate as the output increases. Therefore, it is necessary to set an optimum film thickness. The recording magnetic layer is usually formed as a thin film by sputtering.
　剥離層３には、実質的に酸素、窒素、ハロゲンを含有しない還元性のガスにより還元除去できる物質を使用する。このような物質としては、例えば、炭素、ノボラック系樹脂、アクリル酸エステル類、脂環式エポキシ類などを挙げることができるが、本発明では、還元性ガスに対するエッチング容易性からノボラック系樹脂を用いることが好ましい。 The release layer 3 is made of a material that can be reduced and removed by a reducing gas that does not substantially contain oxygen, nitrogen, or halogen. Examples of such substances include carbon, novolak resins, acrylic esters, alicyclic epoxies, and the like. In the present invention, novolak resins are used for ease of etching with reducing gas. It is preferable.
　マスク層４としては、例えば炭素膜を用いることが好ましい。また、炭素膜は、スパッタリング法やＣＶＤ法などにより成膜することができるが、ＣＶＤ法を用いた方がより緻密性の高い炭素膜を成膜することができる。 For example, a carbon film is preferably used as the mask layer 4. The carbon film can be formed by a sputtering method, a CVD method, or the like, but a carbon film with higher density can be formed by using the CVD method.
　マスク層４の厚みは、５ｎｍ～４０ｎｍの範囲とすることが好ましく、より好ましくは１０ｎｍ～３０ｎｍの範囲である。マスク層４の厚みが５ｎｍより薄いと、このマスク層４のエッジ部分がだれて磁気記録パターンの形成特性が悪化することになる。また、レジスト層５、マスク層４及び剥離層３を透過したイオンが磁性層２に侵入して、磁性層２の磁気特性を悪化させることになる。一方、マスク層４の厚みが４０ｎｍより厚くなると、このマスク層４のエッチング時間が長くなり生産性が低下することになる。 The thickness of the mask layer 4 is preferably in the range of 5 nm to 40 nm, more preferably in the range of 10 nm to 30 nm. If the thickness of the mask layer 4 is less than 5 nm, the edge portion of the mask layer 4 will fall and the magnetic recording pattern formation characteristics will deteriorate. In addition, ions that have passed through the resist layer 5, the mask layer 4, and the release layer 3 enter the magnetic layer 2, and deteriorate the magnetic properties of the magnetic layer 2. On the other hand, when the thickness of the mask layer 4 is greater than 40 nm, the etching time of the mask layer 4 becomes longer and the productivity is lowered.
　次に、図１（ｂ）に示すように、このマスク層４の上にレジスト層５を形成した後、このレジスト層５を、例えばフォトリソグラフィー法やナノインプリント法などを用いて、磁気記録パターンに対応した形状にパターニングする。これにより、レジスト層５の表面には、図１（ｃ）に示すように、磁気記録パターンに対応した部分が凸部５ａ、その間が凹部５ｂとなる凹凸パターンが形成される。 Next, as shown in FIG. 1B, after a resist layer 5 is formed on the mask layer 4, the resist layer 5 is formed into a magnetic recording pattern by using, for example, a photolithography method or a nanoimprint method. Pattern to the corresponding shape. Thereby, as shown in FIG.1 (c), the uneven | corrugated pattern from which the part corresponding to a magnetic-recording pattern becomes the convex part 5a, and the space | interval becomes the recessed part 5b is formed in the surface of the resist layer 5. FIG.
　レジスト層５に凹凸パターンを形成する方法は、通常のフォトリソグラフィー技術を用いることができるが、磁気記録パターンのネガパターンを有するスタンプを用いて、そのネガパターンをレジスト層５に転写する方法を用いることが作業効率の点から好ましい。 As a method for forming the concavo-convex pattern on the resist layer 5, a normal photolithography technique can be used. However, a method of transferring the negative pattern to the resist layer 5 using a stamp having a negative pattern of the magnetic recording pattern is used. It is preferable from the viewpoint of work efficiency.
　レジスト層５には、放射線照射により硬化性を有する材料を用い、このレジスト層５にスタンプを用いて磁気記録パターンのネガパターンを転写する際、又は、パターン転写工程の後には、レジスト層５に放射線を照射することが好ましい。これにより、レジスト層５にスタンプの形状を精度良く転写することが可能となり、後述するマスク層４のエッチング工程において、炭素マスク層４のエッジの部分のダレを無くし、マスク層４のミリングイオンに対する遮蔽性を向上させ、また、マスク層４による磁気記録パターン形成特性を向上させることができる。 The resist layer 5 is made of a material that is curable by radiation irradiation. When a negative pattern of a magnetic recording pattern is transferred to the resist layer 5 using a stamp, or after the pattern transfer step, the resist layer 5 It is preferable to irradiate with radiation. This makes it possible to accurately transfer the stamp shape to the resist layer 5, eliminates sagging of the edge portion of the carbon mask layer 4 in the etching process of the mask layer 4 to be described later, and prevents the mask layer 4 against milling ions. The shielding property can be improved, and the magnetic recording pattern forming characteristics by the mask layer 4 can be improved.
　具体的に、本発明では、レジスト層５にスタンプを用いてネガパターンを転写する工程に際して、レジスト層５の流動性が高い状態で、レジスト層５にスタンプを押圧し、その押圧した状態で、レジスト層５に放射線を照射することによりレジスト層５を硬化させ、その後、スタンプをレジスト層５から離すことにより、スタンプの形状を精度良く、レジスト層５に転写することが可能となる。 Specifically, in the present invention, in the step of transferring a negative pattern using a stamp to the resist layer 5, the resist layer 5 is pressed with a high fluidity, and the resist layer 5 is pressed, and in the pressed state, By irradiating the resist layer 5 with radiation, the resist layer 5 is cured, and then the stamp is separated from the resist layer 5 so that the shape of the stamp can be transferred to the resist layer 5 with high accuracy.
　レジスト層５にスタンプを押圧した状態で、レジスト層５に放射線を照射する方法としては、スタンプの反対側、すなわち非磁性基板１側から放射線を照射する方法、スタンプの材料として放射線を透過できる物質を選択し、スタンプ側から放射線を照射する方法、スタンプの側面から放射線を照射する方法、熱線のように固体に対して伝導性の高い放射線を用いて、スタンプ又は非磁性基板１からの熱伝導により放射線を照射する方法を用いることができる。 As a method of irradiating the resist layer 5 with radiation while the stamp is pressed against the resist layer 5, a method of irradiating radiation from the opposite side of the stamp, that is, the non-magnetic substrate 1 side, a substance capable of transmitting radiation as a stamp material The method of irradiating radiation from the stamp side, the method of irradiating radiation from the side of the stamp, the heat conduction from the stamp or the non-magnetic substrate 1 using radiation having high conductivity with respect to a solid such as heat rays The method of irradiating with radiation can be used.
　なお、本発明における放射線とは、熱線、可視光線、紫外線、Ｘ線、ガンマ線などの広い概念の電磁波のことを言う。また、放射線を照射することにより硬化する材料としては、例えば、熱線に対しては熱硬化樹脂、紫外線に対しては紫外線硬化樹脂を挙げることができる。 In addition, the radiation in this invention means the electromagnetic waves of wide concepts, such as a heat ray, visible light, an ultraviolet-ray, an X-ray, a gamma ray. Examples of the material that is cured by irradiation with radiation include a thermosetting resin for heat rays and an ultraviolet curable resin for ultraviolet rays.
　また、レジスト層５には、このような材料の中でも、ＳｉＯ２系レジストを用いることが好ましく、その中でも特にＳＯＧ（Spin On Glass）を用いることが好ましい。ＳｉＯ２系レジストは、酸素ガスを用いたドライエッチングに対して耐性が高く、炭素膜からなるマスク層４に磁気記録パターンに対応した凹凸パターンを形成する際に、像のぼけを低減することができる。すなわち、炭素膜からなるマスク層４は、酸素ガスを用いたドライエッチングによって容易に加工が可能であり、一方で、ＳｉＯ２系レジストは、酸素ガスを用いたドライエッチングに対して耐性が高いため、ドライエッチングによりマスク層４を垂直に切り立った形状に加工することが可能となり、その結果、磁性層２にシャープな形状の磁気記録パターンを形成することが可能となる。 Further, among these materials, it is preferable to use a SiO 2 resist, and it is particularly preferable to use SOG (Spin On Glass). The SiO 2 resist is highly resistant to dry etching using oxygen gas, and can reduce image blur when forming a concavo-convex pattern corresponding to the magnetic recording pattern on the mask layer 4 made of a carbon film. it can. That is, the mask layer 4 made of a carbon film can be easily processed by dry etching using oxygen gas, while the SiO 2 resist is highly resistant to dry etching using oxygen gas. Then, it becomes possible to process the mask layer 4 into a vertically vertical shape by dry etching, and as a result, a sharp magnetic recording pattern can be formed on the magnetic layer 2.
　また、上述したパターンを転写する工程では、スタンプとして、例えば、金属プレートに電子線描画などの方法を用いて微細なトラックパターンを形成したスタンパを用いることができる。また、スタンパには、上記プロセスに耐え得る硬度及び耐久性が要求されるため、例えばＮｉなどが使用されるが、上記目的に合致するものであれば、その材質について特に限定されるものではない。さらに、スタンプには、通常のデータを記録するトラックの他にも、バーストパターンや、グレイコードパターン、プリアンブルパターンなどといったサーボ信号のパターンも形成することができる。 In the above-described pattern transfer process, a stamper in which a fine track pattern is formed on a metal plate by using a method such as electron beam drawing can be used as the stamp. Further, since the stamper is required to have hardness and durability that can withstand the above process, for example, Ni or the like is used. However, the material is not particularly limited as long as it meets the above purpose. . Further, in addition to the track for recording normal data, a servo signal pattern such as a burst pattern, a gray code pattern, and a preamble pattern can be formed on the stamp.
　レジスト層５に磁気記録パターンに対応した凹凸パターン（凸部５ａ及び凹部５ｂ）を形成した後、このレジスト層５の凹部５ｂにおける厚みは、０～２０ｎｍの範囲とすることが好ましい。これにより、後述するマスク層４、剥離層３及び磁性層２のエッチング工程において、マスク層４のエッジの部分のダレを無くし、マスク層４のミリングイオンに対する遮蔽性を向上させ、また、マスク層４による磁気記録パターンの形成特性を向上させることができる。 After forming a concavo-convex pattern (convex portion 5a and concave portion 5b) corresponding to the magnetic recording pattern on the resist layer 5, the thickness of the concave portion 5b of the resist layer 5 is preferably in the range of 0 to 20 nm. This eliminates sagging of the edge portion of the mask layer 4 in the etching process of the mask layer 4, the release layer 3, and the magnetic layer 2, which will be described later, and improves the shielding property against milling ions of the mask layer 4. 4 can improve the formation characteristics of the magnetic recording pattern.
　また、レジスト層５の凹凸パターンのうち、凸部５ａの幅Ｗは２００ｎｍ以下、凹部５ｂの幅Ｌは１００ｎｍ以下、その合計の幅Ｐ（＝Ｗ＋Ｌ）は３００ｎｍ以下とすることが好ましく、これらの幅ができるだけ狭くなるように形成することが好ましい。最終的に、凸部５ａの幅Ｗが磁性層２の磁性部分（磁気記録パターン）の幅、凹部５ｂの幅Ｌが磁性層２の非磁性部分（凹部又は改質部）の幅、その合計の幅Ｐがトラックピッチとなるからであり、記録密度を高めるためにはこれらの幅をできるだけ狭くすることが好ましい。 Of the concavo-convex pattern of the resist layer 5, the width W of the convex portion 5a is 200 nm or less, the width L of the concave portion 5b is preferably 100 nm or less, and the total width P (= W + L) is preferably 300 nm or less. It is preferable that the width be as narrow as possible. Finally, the width W of the convex portion 5a is the width of the magnetic portion (magnetic recording pattern) of the magnetic layer 2, and the width L of the concave portion 5b is the width of the nonmagnetic portion (recessed portion or modified portion) of the magnetic layer 2. This is because the width P becomes the track pitch, and in order to increase the recording density, it is preferable to make these widths as narrow as possible.
　次に、図１（ｄ）に示すように、このパターニングされたレジスト層５を用いたドライエッチングにより、レジスト層５の凹部５ｂと、その直下にあるマスク層４及び剥離層３を除去する。これにより、マスク層４及び剥離層３を磁気記録パターンに対応した形状にパターニングすることができ、このパターニングされたマスク層４及び剥離層３の間から磁性層２が露出した状態となる。また、マスク層４の上にレジスト層５が形成されていることにより、このマスク層４の角部が丸まった形状となることが防止され、垂直に切り立った形状でパターニングされる。このマスク層４のパターニングには、反応性イオンエッチング、イオンミリングなどのドライエッチングを用いることができるが、その中でも特に、ＩＣＰ（Ｉｎｄｕｃｔｉｖｅ　Ｃｏｕｐｌｅｄ　Ｐｌａｓｍａ）装置による反応性イオンエッチングを用いることが好ましい。 Next, as shown in FIG. 1 (d), the recess 5 b of the resist layer 5, the mask layer 4 and the peeling layer 3 immediately below the resist layer 5 are removed by dry etching using the patterned resist layer 5. Thereby, the mask layer 4 and the release layer 3 can be patterned into a shape corresponding to the magnetic recording pattern, and the magnetic layer 2 is exposed from between the patterned mask layer 4 and the release layer 3. Further, since the resist layer 5 is formed on the mask layer 4, it is possible to prevent the corners of the mask layer 4 from being rounded, and patterning is performed in a vertically standing shape. For the patterning of the mask layer 4, dry etching such as reactive ion etching or ion milling can be used. Among them, reactive ion etching using an ICP (Inductively Coupled Plasma) apparatus is particularly preferable.
　次に、図１（ｅ）に示すように、このパターニングされたマスク層４を用いたドライエッチングにより、磁性層２の剥離層３、マスク層４及びレジスト層５で覆われていない箇所を部分的に除去する。これにより、当該箇所に凹部７と、凹部７の間に磁気的に分離された磁気記録パターン２ａとが形成される。 Next, as shown in FIG. 1E, a portion of the magnetic layer 2 that is not covered with the release layer 3, the mask layer 4 and the resist layer 5 is partially etched by dry etching using the patterned mask layer 4. To remove. As a result, the concave portion 7 and the magnetic recording pattern 2a magnetically separated between the concave portions 7 are formed at the location.
　磁性層２をパターニングする際は、反応性イオンエッチング、イオンミリングなどのドライエッチングを用いることができるが、この磁性層２のドライエッチングについては、例えばＩＣＰやＲＩＥなどの反応性イオンエッチング装置を用いて、ＡｒガスやＮ２ガス等の不活性ガスを導入して行うことが好ましい。 When patterning the magnetic layer 2, dry etching such as reactive ion etching or ion milling can be used. For dry etching of the magnetic layer 2, for example, a reactive ion etching apparatus such as ICP or RIE is used. It is preferable to carry out by introducing an inert gas such as Ar gas or N 2 gas.
　本発明では、上述したＩＣＰ装置を用いてマスク層４のレジスト層５で覆われていない箇所を反応性イオンエッチングにより除去する際は、酸素ガスを用いることが好ましいものの、その後の溶解層３及び磁性層２のドライエッチングについては、例えばＩＣＰやＲＩＥなどの反応性イオンエッチング装置を用いて、ＡｒガスやＮ２ガス等の不活性ガスを導入して行うことが好ましい。すなわち、本発明では、マスク層４のミリングイオンと剥離層３及び磁性層２のミリングイオンとをそれぞれ最適なもの、例えばマスク層４は酸素ガスを用いたＩＣＰ、剥離層３及び磁性層２はＡｒ、Ｎ２ガスを用いたイオンミリングに変更することが好ましい。 In the present invention, when the portion of the mask layer 4 not covered with the resist layer 5 is removed by reactive ion etching using the above-described ICP apparatus, oxygen gas is preferably used, but the subsequent dissolved layer 3 and The dry etching of the magnetic layer 2 is preferably performed by introducing an inert gas such as Ar gas or N 2 gas using a reactive ion etching apparatus such as ICP or RIE. That is, in the present invention, the milling ions of the mask layer 4 and the milling ions of the release layer 3 and the magnetic layer 2 are optimum, for example, the mask layer 4 is an ICP using oxygen gas, and the release layer 3 and the magnetic layer 2 are It is preferable to change to ion milling using Ar, N 2 gas.
　本発明では、このような方法を採用することにより、残された磁性層２のエッジ部を垂直に形成することが可能となる。これは、磁性層２の上の剥離層３及びマスク層４が垂直に切り立った形状であるため、その下の磁性層２も同様の形状となるためである。これにより、フリンジ特性の優れた磁性層２（磁気記録パターン２ａ）を形成することができる。なお、この工程でイオンミリングにＮ２ガスを使用しても、磁気記録パターン２ａの表面は剥離層３及びマスク層４によって保護されているため、磁気記録パターン２ａの表面が窒化されて磁気特性を悪化させることはない。 In the present invention, by adopting such a method, the remaining edge portion of the magnetic layer 2 can be formed vertically. This is because the peeling layer 3 and the mask layer 4 on the magnetic layer 2 are vertically cut, and the magnetic layer 2 therebelow has the same shape. Thereby, the magnetic layer 2 (magnetic recording pattern 2a) having excellent fringe characteristics can be formed. Even if N 2 gas is used for ion milling in this step, the surface of the magnetic recording pattern 2a is protected by the release layer 3 and the mask layer 4, so that the surface of the magnetic recording pattern 2a is nitrided and has magnetic characteristics. Will not worsen.
　次に、図１（ｆ）に示すように、実質的に酸素、窒素、ハロゲンを含まない還元性のガスを用いて剥離層３を還元除去することによって、この剥離層３と共にマスク層４及びレジスト層５を磁性層２の上から除去する。 Next, as shown in FIG. 1 (f), the release layer 3 is reduced and removed using a reducing gas substantially free of oxygen, nitrogen, and halogen, so that the release layer 3 and the mask layer 4 and The resist layer 5 is removed from above the magnetic layer 2.
　ここで、レジスト層４やマスク層３の除去には、一般的にドライエッチングが使用され、エッチング力の大きなガスとして、一般的に酸素、窒素、ハロゲンが使用されている。すなわち、これらのエッチングガスは、被エッチング物を酸化、窒化、ハロゲン化しながら、ＣＯやＣＯ２などの酸化物、窒化物、ハロゲン化物として除去する。 Here, dry etching is generally used for removing the resist layer 4 and the mask layer 3, and oxygen, nitrogen, and halogen are generally used as gases having a large etching power. That is, these etching gases are removed as oxides, nitrides, and halides such as CO and CO 2 while oxidizing, nitriding, and halogenating the object to be etched.
　しかしながら、本発明者による検討の結果、磁気記録パターン２ａを形成した後のレジスト層５やマスク層４の除去に、エッチングガスとして酸素、窒素、ハロゲンを使用すると、磁性層２（磁気記録パターン２ａ）の表面がわずかに酸化、窒化、ハロゲン化し、その酸化物、窒素物、ハロゲン化物が磁気記録媒体の電磁変換特性を低下させることが明らかになった。 However, as a result of studies by the present inventors, when oxygen, nitrogen, or halogen is used as an etching gas to remove the resist layer 5 and the mask layer 4 after the magnetic recording pattern 2a is formed, the magnetic layer 2 (magnetic recording pattern 2a ) Was slightly oxidized, nitrided and halogenated, and the oxides, nitrides and halides were found to deteriorate the electromagnetic conversion characteristics of the magnetic recording medium.
　そこで、本発明では、実質的に酸素、窒素、ハロゲンを含まない還元性のガスを用いて剥離層３を還元除去し、この剥離層３と共にマスク層４及びレジスト層５を磁性層２の上から除去（リフトオフ）することを趣旨とする。これにより、磁性層２の表面の酸化、窒化、ハロゲン化を防止し、磁気記録媒体の電磁変換特性の改善を図ることが可能である。 Therefore, in the present invention, the release layer 3 is reduced and removed using a reducing gas substantially free of oxygen, nitrogen, and halogen, and the mask layer 4 and the resist layer 5 are formed on the magnetic layer 2 together with the release layer 3. It is intended to be removed (lifted off). Thereby, oxidation, nitridation, and halogenation of the surface of the magnetic layer 2 can be prevented, and the electromagnetic conversion characteristics of the magnetic recording medium can be improved.
　すなわち、本発明では、剥離層３に還元除去できる物質を使用し、マスク層４及びレジスト層５の除去に、剥離層３に対する還元性を持ちながら、磁性層２に対する酸化性、窒化性、ハロゲン化性をほとんど持たないガスを使用する。 In other words, in the present invention, a substance that can be reduced and removed is used for the release layer 3, and the removal of the mask layer 4 and the resist layer 5 has reducibility for the release layer 3, while oxidizing, nitriding, and halogenating the magnetic layer 2. Use gas that has almost no chemical effect.
　実質的に酸素、窒素、ハロゲンを含有しない還元性のガスとしては、例えば水素等を含むガスを用いることができる。より具体的には、水素の含有量が６０体積％以上、より好ましくは８０体積％以上であって、酸素、窒素、ハロゲンの合計含有量が１５体積％以下、より好ましくは１０体積％以下のガスを用いることができる。 As the reducing gas that substantially does not contain oxygen, nitrogen, or halogen, for example, a gas containing hydrogen or the like can be used. More specifically, the hydrogen content is 60% by volume or more, more preferably 80% by volume or more, and the total content of oxygen, nitrogen and halogen is 15% by volume or less, more preferably 10% by volume or less. Gas can be used.
　また、レジスト層５及びマスク層４を除去した後は、磁性層２の表面にＡｒなどの不活性ガスを照射して、この磁性層２の表層を１～２ｎｍの範囲でエッチングにより除去することが好ましい。これにより、磁性層２の一部に、改質により磁気特性が低下した部位が生じていた場合であっても、その磁気特性の低下した部位を除去することができ、本発明の効果をより高めることができる。すなわち、上述したレジスト層５やマスク層４の除去に、実質的に酸素、窒素、ハロゲンを含有しない還元性のガスを使用しても、これらのガスに不可避的に酸素等が含有されると、磁性層２の表面がわずかに酸化等される場合があるからである。 Further, after removing the resist layer 5 and the mask layer 4, the surface of the magnetic layer 2 is irradiated with an inert gas such as Ar, and the surface layer of the magnetic layer 2 is removed by etching in the range of 1 to 2 nm. Is preferred. As a result, even if a part of the magnetic layer 2 has a portion where the magnetic properties have been lowered due to the modification, the portion having the lowered magnetic properties can be removed, and the effects of the present invention can be further improved. Can be increased. That is, even if a reducing gas that does not substantially contain oxygen, nitrogen, or halogen is used to remove the resist layer 5 or the mask layer 4 described above, oxygen or the like is inevitably contained in these gases. This is because the surface of the magnetic layer 2 may be slightly oxidized.
　次に、図１（ｇ）に示すように、マスク層４及びレジスト層５が除去された面上を覆う保護層６を形成する。この保護層６の形成には、一般的にＤＬＣ(Diamond Like Carbon)薄膜をＰ－ＣＶＤなどを用いて成膜する方法が用いられるが、このような方法に必ずしも限定されるものではない。また、この保護層６は、磁性層２が除去された部分に埋め込まれるのに十分な厚みで形成される。 Next, as shown in FIG. 1G, a protective layer 6 covering the surface from which the mask layer 4 and the resist layer 5 have been removed is formed. For the formation of the protective layer 6, generally, a method of forming a DLC (Diamond Like Carbon) thin film using P-CVD or the like is used, but the method is not necessarily limited to such a method. The protective layer 6 is formed with a thickness sufficient to be embedded in the portion from which the magnetic layer 2 has been removed.
　その後、保護層６の上に潤滑剤を塗布することによって潤滑膜（図示せず。）を形成する。この潤滑膜に用いる潤滑剤としては、フッ素系潤滑剤、炭化水素系潤滑剤及びこれらの混合物などを挙げることができ、通常１～４ｎｍの厚さで潤滑膜を形成する。そして、以上の工程を経ることによって、磁気記録媒体を製造することができる。 Then, a lubricant film (not shown) is formed by applying a lubricant on the protective layer 6. Examples of the lubricant used for the lubricating film include a fluorine-based lubricant, a hydrocarbon-based lubricant, and a mixture thereof, and the lubricating film is usually formed with a thickness of 1 to 4 nm. The magnetic recording medium can be manufactured through the above steps.
　以上のように、本発明を適用した磁気記録媒体の製造方法では、実質的に酸素、窒素、ハロゲンを含まない還元性のガスを用いて剥離層３を還元除去することによって、この剥離層３と共にマスク層４及びレジスト層５を磁性層２の上から除去するため、磁性層２の表面が酸化、窒化、ハロゲン化されることがなく、その結果、電磁変換特性に優れた磁気記録媒体を製造することが可能である。また、このような電磁変換特性に優れた磁気記録媒体を備えた磁気記録再生装置では、記録密度の更なる向上を図ることが可能である。 As described above, in the method of manufacturing a magnetic recording medium to which the present invention is applied, the release layer 3 is reduced and removed using a reducing gas that does not substantially contain oxygen, nitrogen, or halogen, thereby removing the release layer 3. In addition, since the mask layer 4 and the resist layer 5 are removed from above the magnetic layer 2, the surface of the magnetic layer 2 is not oxidized, nitrided, or halogenated, and as a result, a magnetic recording medium having excellent electromagnetic characteristics can be obtained. It is possible to manufacture. Further, in the magnetic recording / reproducing apparatus provided with such a magnetic recording medium having excellent electromagnetic conversion characteristics, it is possible to further improve the recording density.
　次に、本発明を適用した磁気記録媒体の製造方法の他例について説明する。
　本例は、上記磁性層２に磁気記録パターン２ａを形成する方法として、図１に示すように、磁性層２を部分的に除去する代わりに、図２に示すように、磁性層２の磁気特性を部分的に改質する方法を採用する。 Next, another example of a method for manufacturing a magnetic recording medium to which the present invention is applied will be described.
In this example, as a method of forming the magnetic recording pattern 2a on the magnetic layer 2, instead of partially removing the magnetic layer 2 as shown in FIG. A method of partially modifying the characteristics is adopted.
　具体的に、この磁気記録媒体の製造方法は、例えば図２（ａ）～図２（ｇ）に示すように、非磁性基板１の少なくとも一方の面上に磁性層２を形成する工程と、磁性層の上に剥離層３を形成する工程と、剥離層３の上にマスク層４を形成する工程と、マスク層４の上にレジスト層５を形成する工程と、レジスト層５の表面を磁気記録パターンに対応した形状にパターニングする工程と、パターニングされたレジスト層５を用いてマスク層４及び剥離層３をパターニングする工程と、磁性層２のマスク層４及び剥離層３で覆われていない箇所を部分的に改質する工程と、マスク層４及び剥離層３を磁性層２の上から除去する工程と、この上に保護層６を形成する工程と、保護層６の上に潤滑膜を形成する工程（図示せず。）とを含んでいる。 Specifically, the method of manufacturing the magnetic recording medium includes a step of forming a magnetic layer 2 on at least one surface of a nonmagnetic substrate 1 as shown in FIGS. 2 (a) to 2 (g), for example. A step of forming a release layer 3 on the magnetic layer, a step of forming a mask layer 4 on the release layer 3, a step of forming a resist layer 5 on the mask layer 4, and a surface of the resist layer 5 The mask layer 4 and the release layer 3 of the magnetic layer 2 are covered with the step of patterning into a shape corresponding to the magnetic recording pattern, the step of patterning the mask layer 4 and the release layer 3 using the patterned resist layer 5. A step of partially modifying the non-existing portion, a step of removing the mask layer 4 and the release layer 3 from the magnetic layer 2, a step of forming the protective layer 6 thereon, and a lubrication on the protective layer 6 Forming a film (not shown).
　このうち、図２（ａ）～（ｄ）に示す工程は、上記図１（ａ）～（ｄ）に示す工程と基本的に同じである。このため、これら図２（ａ）～（ｄ）に示す工程の説明については省略するものとする。 Among these, the steps shown in FIGS. 2A to 2D are basically the same as the steps shown in FIGS. 1A to 1D. Therefore, the description of the steps shown in FIGS. 2A to 2D will be omitted.
　次に、図２（ｅ）に示すように、例えば反応性プラズマや反応性イオンを用いて、マスク層３の下にある磁性層２のうち、レジスト層５、マスク層４及び剥離層３で覆われていない箇所を部分的に改質し、改質部８の間に磁気的に分離された磁気記録パターン２ｂを形成する。 Next, as shown in FIG. 2 (e), the resist layer 5, the mask layer 4, and the release layer 3 among the magnetic layers 2 under the mask layer 3 are formed using, for example, reactive plasma or reactive ions. The portions that are not covered are partially modified to form magnetically separated magnetic recording patterns 2b between the modified portions 8.
　本発明において、磁気記録パターン２ｂとは、磁気記録媒体を表面側から見た場合、磁性層２の一部の磁気特性を改質した、好ましくは非磁性化した非磁性領域７により分離された状態のものを言う。すなわち、磁性層２が表面側から見て分離されていれば、磁性層２の底部において分離されていなくとも、本発明の目的を達成することが可能であり、本発明において磁気記録パターン２ｂの概念に含まれる。 In the present invention, when the magnetic recording medium is viewed from the surface side, the magnetic recording pattern 2b is separated by a nonmagnetic region 7 which is preferably non-magnetic, with a part of the magnetic properties of the magnetic layer 2 modified. Say things in state. That is, if the magnetic layer 2 is separated from the surface side, the object of the present invention can be achieved even if the magnetic layer 2 is not separated at the bottom of the magnetic layer 2. Included in the concept.
　また、磁気記録パターン２ｂを形成するための磁性層２の改質とは、磁性層２をパターン化するために、この磁性層２の保磁力、残留磁化等を部分的に変化させることを指し、その変化とは、保磁力を下げ、残留磁化を下げることを指す。 Further, the modification of the magnetic layer 2 for forming the magnetic recording pattern 2b refers to partially changing the coercive force, the residual magnetization, etc. of the magnetic layer 2 in order to pattern the magnetic layer 2. The change refers to lowering the coercive force and lowering the remanent magnetization.
　特に、磁気特性の改質として、反応性プラズマや反応性イオンにさらした箇所の磁性層２の磁化量を当初（未処理）の７５％以下、より好ましくは５０％以下、保磁力を当初の５０％以下、より好ましくは２０％以下とする方法を採用するのが好ましい。このような方法を用いてディスクリートトラック型の磁気記録媒体を製造することにより、本媒体に磁気記録を行う際の書きにじみをなくし、高い面記録密度の磁気記録媒体を提供することが可能となる。 In particular, as a modification of the magnetic characteristics, the amount of magnetization of the magnetic layer 2 exposed to reactive plasma or reactive ions is 75% or less of the initial (untreated), more preferably 50% or less, and the coercive force is the initial value. It is preferable to adopt a method of 50% or less, more preferably 20% or less. By manufacturing a discrete track type magnetic recording medium using such a method, it is possible to eliminate writing bleeding when performing magnetic recording on this medium and to provide a magnetic recording medium having a high surface recording density. .
　さらに、本発明では、磁気記録トラック及びサーボ信号パターン部を分離する箇所（改質部８）を、すでに成膜された磁性層２を反応性プラズマや反応性イオンにさらして磁性層２を非晶質化することにより実現することも可能である。すなわち、本発明における磁性層２の磁気特性の改質は、磁性層２の結晶構造の改変によって実現することも含む。 Further, according to the present invention, the magnetic layer 2 is not exposed by exposing the magnetic layer 2 already formed to reactive plasma or reactive ions at a location (the modified portion 8) that separates the magnetic recording track and the servo signal pattern portion. It can also be realized by crystallizing. That is, the modification of the magnetic characteristics of the magnetic layer 2 in the present invention includes realization by modifying the crystal structure of the magnetic layer 2.
　本発明において、磁性層２を非晶質化するとは、磁性層２の原子配列を、長距離秩序を持たない不規則な原子配列の形態とすることを指し、より具体的には、２ｎｍ未満の微結晶粒がランダムに配列した状態とすることを指す。そしてこの原子配列状態を分析手法により確認する場合は、Ｘ線回折または電子線回折により、結晶面を表すピークが認められず、また、ハローが認められるのみの状態とする。 In the present invention, making the magnetic layer 2 amorphous means that the atomic arrangement of the magnetic layer 2 is in an irregular atomic arrangement having no long-range order, and more specifically, less than 2 nm. This means that the microcrystal grains are arranged at random. When this atomic arrangement state is confirmed by an analysis method, a peak representing a crystal plane is not recognized by X-ray diffraction or electron beam diffraction, and only a halo is recognized.
　反応性プラズマとしては、誘導結合プラズマ（ＩＣＰ；Ｉｎｄｕｃｔｉｖｅｌｙ　Ｃｏｕｐｌｅｄ　Ｐｌａｓｍａ）や反応性イオンプラズマ（ＲＩＥ；Ｒｅａｃｔｉｖｅ　Ｉｏｎ　Ｐｌａｓｍａ）が例示できる。また、反応性イオンとしては、上述した誘導結合プラズマ、反応性イオンプラズマ内に存在する反応性のイオンが例示できる。 Examples of reactive plasma include inductively coupled plasma (ICP) and reactive ion plasma (RIE). Examples of reactive ions include reactive ions present in the inductively coupled plasma and reactive ion plasma described above.
　誘導結合プラズマとしては、気体に高電圧をかけることによってプラズマ化し、さらに高周波数の変動磁場によってそのプラズマ内部に渦電流によるジュール熱を発生させることによって得られる高温のプラズマを例示できる。誘導結合プラズマは、電子密度が高く、従来のイオンビームを用いてディスクリートトラックメディアを製造する場合に比べ、広い面積の磁性膜において、高い効率で磁気特性の改質を実現することができる。 Examples of inductively coupled plasma include high-temperature plasma obtained by applying high voltage to a gas and generating Joule heat due to eddy current in the plasma by a high-frequency variable magnetic field. Inductively coupled plasma has a high electron density, and can improve the magnetic properties with high efficiency in a magnetic film having a large area, compared to the case where a discrete track medium is manufactured using a conventional ion beam.
　反応性イオンプラズマとは、プラズマ中にＯ２、ＳＦ６、ＣＨＦ３、ＣＦ４、ＣＣｌ４等の反応性ガスを加えた反応性の高いプラズマである。このようなプラズマを用いることにより、磁性層２の磁気特性の改質をより高い効率で実現することが可能となる。 The reactive ion plasma is a highly reactive plasma in which a reactive gas such as O 2 , SF 6 , CHF 3 , CF 4 , or CCl 4 is added to the plasma. By using such plasma, it is possible to realize the modification of the magnetic characteristics of the magnetic layer 2 with higher efficiency.
　本発明では、磁性層２を反応性プラズマにさらすことにより磁性層２を改質するが、この改質は、磁性層２を構成する磁性金属と反応性プラズマ中の原子またはイオンとの反応により実現するのが好ましい。 In the present invention, the magnetic layer 2 is modified by exposing the magnetic layer 2 to a reactive plasma. This modification is performed by a reaction between a magnetic metal constituting the magnetic layer 2 and atoms or ions in the reactive plasma. It is preferable to realize.
　この場合、反応とは、磁性金属に反応性プラズマ中の原子等が侵入し、磁性金属の結晶構造が変化すること、磁性金属の組成が変化すること、磁性金属が酸化すること、磁性金属が窒化すること、磁性金属が珪化すること等が例示できる。 In this case, the reaction means that atoms in the reactive plasma enter the magnetic metal, change the crystal structure of the magnetic metal, change the composition of the magnetic metal, oxidize the magnetic metal, Examples include nitriding, silicidation of magnetic metal, and the like.
　特に、反応性プラズマとして酸素原子を含有させ、磁性層２を構成する磁性金属と反応性プラズマ中の酸素原子とを反応させることにより、磁性層２を酸化させることが好ましい。磁性層２を部分的に酸化させることにより、酸化部分の残留磁化及び保磁力等を効率よく低減させることが可能となるため、短時間の反応性プラズマ処理により、磁気記録パターンを有する磁気記録媒体を製造することが可能となるからである。 In particular, it is preferable to oxidize the magnetic layer 2 by containing oxygen atoms as reactive plasma and reacting the magnetic metal constituting the magnetic layer 2 with oxygen atoms in the reactive plasma. By partially oxidizing the magnetic layer 2, it is possible to efficiently reduce the remanent magnetization, coercive force, etc. of the oxidized portion, so that a magnetic recording medium having a magnetic recording pattern can be obtained by a reactive plasma treatment in a short time. It is because it becomes possible to manufacture.
　また、反応性プラズマには、ハロゲン原子を含有させることが好ましい。特に、ハロゲン原子として、Ｆ原子を用いることが好ましい。ハロゲン原子は、酸素原子と一緒に反応性プラズマ中に添加して用いてもよく、また酸素原子を用いずに反応性プラズマ中に添加してもよい。上述したように、反応性プラズマに酸素原子等を加えることにより、磁性層２を構成する磁性金属と酸素原子等が反応して磁性層２の磁気特性を改質させることが可能となる。この際、反応性プラズマにハロゲン原子を含有させることにより、この反応性をさらに高めることが可能となる。 In addition, it is preferable to contain halogen atoms in the reactive plasma. In particular, it is preferable to use an F atom as the halogen atom. The halogen atom may be added to the reactive plasma together with the oxygen atom, or may be added to the reactive plasma without using the oxygen atom. As described above, by adding oxygen atoms or the like to the reactive plasma, the magnetic metal constituting the magnetic layer 2 reacts with oxygen atoms or the like, so that the magnetic characteristics of the magnetic layer 2 can be modified. At this time, the reactivity can be further increased by adding halogen atoms to the reactive plasma.
　また、反応性プラズマ中に酸素原子を添加していない場合においても、ハロゲン原子が磁性合金と反応して、磁性層２の磁気特性を改質させることが可能となる。この理由の詳細は明らかではないが、反応性プラズマ中のハロゲン原子が、磁性層２の表面に形成している異物をエッチングし、これにより磁性層２の表面が清浄化し、磁性層２の反応性が高まることが考えられる。 In addition, even when oxygen atoms are not added to the reactive plasma, halogen atoms can react with the magnetic alloy to improve the magnetic properties of the magnetic layer 2. Although the details of this reason are not clear, the halogen atoms in the reactive plasma etch foreign matter formed on the surface of the magnetic layer 2, thereby cleaning the surface of the magnetic layer 2 and reacting the magnetic layer 2. It is considered that the property is increased.
　また、清浄化した磁性層表面とハロゲン原子とが高い効率で反応することが考えられる。このような効果を有するハロゲン原子としてＦ原子を用いるのが特に好ましい。 Also, it is conceivable that the cleaned magnetic layer surface and halogen atoms react with high efficiency. It is particularly preferable to use an F atom as the halogen atom having such an effect.
　次に、図２（ｆ）以降に示す工程についても、上記図１（ｆ）以降に示す工程と基本的に同じである。このため、図２（ｆ）以降に示す工程の説明については省略するものとする。 Next, the steps shown in FIG. 2 (f) and thereafter are basically the same as the steps shown in FIG. 1 (f) and thereafter. For this reason, the description of the steps shown in FIG.
　したがって、この図２に示す磁気記録媒体の製造方法においても、実質的に酸素、窒素、ハロゲンを含まない還元性のガスを用いて剥離層２を還元除去することによって、この剥離層２と共にマスク層４及びレジスト層５を磁性層２の上から除去するため、磁性層２の表面が酸化、窒化、ハロゲン化されることがなく、その結果、電磁変換特性に優れた磁気記録媒体を製造することが可能である。また、このような電磁変換特性に優れた磁気記録媒体を備えた磁気記録再生装置では、記録密度の更なる向上を図ることが可能である。 Therefore, also in the method of manufacturing the magnetic recording medium shown in FIG. 2, the release layer 2 is reduced and removed by using a reducing gas substantially free of oxygen, nitrogen, and halogen, so that the mask together with the release layer 2 is masked. Since the layer 4 and the resist layer 5 are removed from above the magnetic layer 2, the surface of the magnetic layer 2 is not oxidized, nitrided or halogenated, and as a result, a magnetic recording medium having excellent electromagnetic conversion characteristics is manufactured. It is possible. Further, in the magnetic recording / reproducing apparatus provided with such a magnetic recording medium having excellent electromagnetic conversion characteristics, it is possible to further improve the recording density.
　なお、本発明は、上記実施形態のものに必ずしも限定されるものではなく、本発明の趣旨を逸脱しない範囲において種々の変更を加えることが可能である。
　例えば、本発明では、上記マスク層４にスタンプを用いて磁気記録パターン２ａに対応した形状の凹凸パターンを転写できる場合は、このマスク層４の上に上記レジスト層５を設ける必要がなく、この場合、マスク層４にスタンプを用いて磁気記録パターンに対応した凹凸パターンを転写した後、このパターニングされたマスク層４を用いて、上記磁性層２に磁気的に分離された磁気記録パターン２ａ（２ｂ）を形成すればよい。 In addition, this invention is not necessarily limited to the thing of the said embodiment, A various change can be added in the range which does not deviate from the meaning of this invention.
For example, in the present invention, when the concave / convex pattern having a shape corresponding to the magnetic recording pattern 2a can be transferred to the mask layer 4 using a stamp, it is not necessary to provide the resist layer 5 on the mask layer 4. In this case, after a concave / convex pattern corresponding to the magnetic recording pattern is transferred to the mask layer 4 using a stamp, the magnetic recording pattern 2a (which is magnetically separated into the magnetic layer 2 using the patterned mask layer 4). 2b) may be formed.
　また、本発明では、上記磁性層２に磁気記録パターンを形成する方法として、上記磁性層２の剥離層３、マスク層４及びレジスト層５で覆われていない箇所を部分的に除去して、磁性層２に凹部を形成した後、この凹部の磁気特性を部分的に改質する方法を採用することも可能である。 Further, in the present invention, as a method of forming a magnetic recording pattern on the magnetic layer 2, a portion of the magnetic layer 2 that is not covered with the release layer 3, the mask layer 4 and the resist layer 5 is partially removed, It is also possible to adopt a method of partially modifying the magnetic characteristics of the recess after forming the recess in the magnetic layer 2.
　また、本発明では、磁性層２が表面側から見て分離されていれば、磁性層２の底部において分離されていなくとも、本発明の目的を達成することが可能であり、本発明の磁気的に分離された磁気記録パターンの概念に含まれる。 In the present invention, if the magnetic layer 2 is separated from the surface side, the object of the present invention can be achieved even if the magnetic layer 2 is not separated at the bottom of the magnetic layer 2. Included in the concept of magnetically separated magnetic recording patterns.
　なお、本発明は、磁気的に分離された磁気記録パターンを有する磁気記録媒体に対して幅広く適用することが可能であり、この磁気記録パターンを有する磁気記録媒体としては、磁気記録パターンが１ビットごとに一定の規則性をもって配置された、いわゆるパターンドメディアや、磁気記録パターンがトラック状に配置されたメディア、その他、サーボ信号パターン等を含む磁気記録媒体を挙げることができる。本発明は、この中でも磁気的に分離された磁気記録パターンが磁気記録トラック及びサーボ信号パターンである、いわゆるディスクリート型の磁気記録媒体に適用することが、その製造における簡便性から好ましい。 The present invention can be widely applied to a magnetic recording medium having a magnetically separated magnetic recording pattern. As a magnetic recording medium having this magnetic recording pattern, the magnetic recording pattern is 1 bit. Examples thereof include so-called patterned media arranged with a certain regularity, media with magnetic recording patterns arranged in a track shape, and other magnetic recording media including servo signal patterns. Among these, the present invention is preferably applied to a so-called discrete type magnetic recording medium in which magnetically separated magnetic recording patterns are magnetic recording tracks and servo signal patterns, from the viewpoint of simplicity in manufacturing.
（磁気記録再生装置）
　次に、本発明を適用した磁気記録再生装置（ＨＤＤ）について説明する。
　本発明を適用した磁気記録再生装置は、例えば図３に示すように、上記本発明の製造方法により製造された磁気記録媒体３０と、磁気記録媒体３０を回転駆動する回転駆動部５１と、磁気記録媒体３０に対する記録動作と再生動作とを行う磁気ヘッド５２と、磁気ヘッド５２を磁気記録媒体３０の径方向に移動させるヘッド駆動部５３と、磁気ヘッド５２への信号入力と磁気ヘッド５２から出力信号の再生とを行うための記録再生信号処理系５４とを備えている。 (Magnetic recording / reproducing device)
Next, a magnetic recording / reproducing apparatus (HDD) to which the present invention is applied will be described.
A magnetic recording / reproducing apparatus to which the present invention is applied includes, for example, as shown in FIG. 3, a magnetic recording medium 30 manufactured by the manufacturing method of the present invention, a rotational drive unit 51 that rotationally drives the magnetic recording medium 30, and a magnetic A magnetic head 52 that performs a recording operation and a reproducing operation on the recording medium 30, a head drive unit 53 that moves the magnetic head 52 in the radial direction of the magnetic recording medium 30, a signal input to the magnetic head 52, and an output from the magnetic head 52 And a recording / reproducing signal processing system 54 for reproducing the signal.
　この磁気記録再生装置では、上記ディスクリートトラック型の磁気記録媒体３０を用いることにより、この磁気記録媒体３０に磁気記録を行う際の書きにじみをなくし、高い面記録密度を得ることが可能である。すなわち、上記磁気記録媒体３０を用いることで記録密度の高い磁気記録再生装置を構成することが可能となる。また、上記磁気記録媒体３０の記録トラックを磁気的に不連続に加工したことによって、従来はトラックエッジ部の磁化遷移領域の影響を排除するために再生ヘッド幅を記録ヘッド幅よりも狭くして対応していたものを、両者をほぼ同じ幅にして動作させることができる。これにより十分な再生出力と高いＳＮＲを得ることができるようになる。 In this magnetic recording / reproducing apparatus, by using the discrete track type magnetic recording medium 30, it is possible to eliminate writing blur when performing magnetic recording on the magnetic recording medium 30 and to obtain a high surface recording density. That is, by using the magnetic recording medium 30, a magnetic recording / reproducing apparatus having a high recording density can be configured. In addition, by processing the recording track of the magnetic recording medium 30 magnetically discontinuously, conventionally, the reproducing head width is made narrower than the recording head width in order to eliminate the influence of the magnetization transition region at the track edge portion. What was supported can be operated with both of them approximately the same width. As a result, sufficient reproduction output and high SNR can be obtained.
　さらに、磁気ヘッド５２の再生部をＧＭＲヘッド又はＴＭＲヘッドで構成することにより、高記録密度においても十分な信号強度を得ることができ、高記録密度を持った磁気記録再生装置を実現することができる。また、この磁気ヘッド５２の浮上量を０．００５μｍ～０．０２０μｍの範囲内とし、従来より低い高さで浮上させると、出力が向上して高い装置ＳＮＲが得られ、大容量で高信頼性の磁気記録再生装置を提供することができる。 Furthermore, by configuring the reproducing unit of the magnetic head 52 with a GMR head or a TMR head, a sufficient signal intensity can be obtained even at a high recording density, and a magnetic recording / reproducing apparatus having a high recording density can be realized. it can. Further, when the flying height of the magnetic head 52 is within the range of 0.005 μm to 0.020 μm and the flying height is lower than the conventional height, the output is improved and a high device SNR is obtained, and the large capacity and the high reliability are obtained. The magnetic recording / reproducing apparatus can be provided.
　さらに、最尤復号法による信号処理回路を組み合わせるとさらに記録密度を向上でき、例えば、トラック密度１００ｋトラック／インチ以上、線記録密度１０００ｋビット／インチ以上、１平方インチ当たり１００Ｇビット以上の記録密度で記録・再生する場合にも十分なＳＮＲが得られる。 Further, when the signal processing circuit based on the maximum likelihood decoding method is combined, the recording density can be further improved. For example, the track density is 100 k tracks / inch or more, the linear recording density is 1000 k bits / inch or more, and the recording density is 100 G bits or more per square inch. A sufficient SNR can also be obtained when recording / reproducing.
　以下、実施例により本発明の効果をより明らかなものとする。なお、本発明は、以下の実施例に限定されるものではなく、その要旨を変更しない範囲で適宜変更して実施することができる。 Hereinafter, the effects of the present invention will be made clearer by examples. In addition, this invention is not limited to a following example, In the range which does not change the summary, it can change suitably and can implement.
（実施例１）
　実施例１では、先ず、ＨＤ用ガラス基板をセットした真空チャンバを予め１．０×１０－５Ｐａ以下に真空排気した。ここで使用したガラス基板は、Ｌｉ２Ｓｉ２Ｏ５、Ａｌ２Ｏ３－Ｋ２Ｏ、Ａｌ２Ｏ３－Ｋ２Ｏ、ＭｇＯ－Ｐ２Ｏ５、Ｓｂ２Ｏ３－ＺｎＯを構成成分とする結晶化ガラスを材質とし、外径が６５ｍｍ、内径が２０ｍｍ、平均表面粗さ（Ｒａ）が２オングストロームである。 Example 1
In Example 1, first, the vacuum chamber in which the glass substrate for HD was set was evacuated to 1.0 × 10 −5 Pa or less in advance. The glass substrate used here is composed of Li 2 Si 2 O 5 , Al 2 O 3 —K 2 O, Al 2 O 3 —K 2 O, MgO—P 2 O 5 , Sb 2 O 3 —ZnO. The crystallized glass is made of a material having an outer diameter of 65 mm, an inner diameter of 20 mm, and an average surface roughness (Ra) of 2 angstroms.
　次に、このガラス基板にＤＣスパッタリング法を用いて、軟磁性層として層厚６０ｎｍのＦｅＣｏＢ膜、中間層として層厚１０ｎｍのＲｕ膜と、記録磁性層として層厚１５ｎｍの７０Ｃｏ－５Ｃｒ－１５Ｐｔ－１０ＳｉＯ２合金膜、層厚１４ｎｍの７０Ｃｏ－５Ｃｒ－１５Ｐｔ合金膜と、剥離層として層厚５０ｎｍのノボラック樹脂膜と、マスク層として層厚２０ｎｍの炭素膜とをこの順で積層した。 Next, this glass substrate was subjected to a DC sputtering method using a FeCoB film with a thickness of 60 nm as a soft magnetic layer, a Ru film with a thickness of 10 nm as an intermediate layer, and a 70 Co-5Cr-15Pt— with a thickness of 15 nm as a recording magnetic layer. A 10SiO 2 alloy film, a 70Co-5Cr-15Pt alloy film with a thickness of 14 nm, a novolak resin film with a thickness of 50 nm as a release layer, and a carbon film with a thickness of 20 nm as a mask layer were laminated in this order.
　次に、この上に、レジストをスピンコート法により塗布し、層厚１００ｎｍのレジスト層を形成した。なお、レジストには、ＳＯＧを用いた。そして、磁気記録パターンのポジパターンを有するガラス製のスタンプを用いて、このスタンプを１ＭＰａ（約８．８ｋｇｆ／ｃｍ２）の圧力でレジスト層に押し付けた状態で、波長２５０ｎｍの紫外線を、紫外線の透過率が９５％以上であるガラス製のスタンプの上部から１０秒間照射し、レジスト層を硬化させた。その後、スタンプをレジスト層から分離し、レジスト層に磁気記録パターンに対応した凹凸パターンを転写した。 Next, a resist was applied thereon by a spin coating method to form a resist layer having a layer thickness of 100 nm. Note that SOG was used as the resist. Then, using a glass stamp having a positive pattern of the magnetic recording pattern, UV light having a wavelength of 250 nm is applied to the resist layer in a state where the stamp is pressed against the resist layer at a pressure of 1 MPa (about 8.8 kgf / cm 2 ). The resist layer was cured by irradiating from the top of a glass stamp having a transmittance of 95% or more for 10 seconds. Thereafter, the stamp was separated from the resist layer, and an uneven pattern corresponding to the magnetic recording pattern was transferred to the resist layer.
　なお、レジスト層に転写した凹凸パターンは、２７１ｋトラック／インチの磁気記録パターンに対応しており、凸部が幅１２０ｎｍの円周状、凹部が幅６０ｎｍの円周状であり、レジスト層の層厚は８０ｎｍ、レジスト層の凹部の深さは約５ｎｍであった。また、凹部の基板面に対する角度は、ほぼ９０度であった。 The concavo-convex pattern transferred to the resist layer corresponds to a magnetic recording pattern of 271 k tracks / inch, with the convex portion having a circumferential shape having a width of 120 nm and the concave portion having a circumferential shape having a width of 60 nm. The thickness was 80 nm, and the depth of the concave portion of the resist layer was about 5 nm. The angle of the recess with respect to the substrate surface was approximately 90 degrees.
　次に、レジスト層の凹部の箇所、並びにその下のマスク層及び剥離層をドライエッチングで除去した。ドライエッチングの条件は、水素ガスを４０ｓｃｃｍ、圧力を０．３Ｐａ、高周波プラズマ電力を３００Ｗ、ＤＣバイアスを３０Ｗ、エッチング時間を３０秒とした。 Next, the concave portion of the resist layer, and the mask layer and release layer thereunder were removed by dry etching. The dry etching conditions were as follows: hydrogen gas was 40 sccm, pressure was 0.3 Pa, high-frequency plasma power was 300 W, DC bias was 30 W, and etching time was 30 seconds.
　次に、記録磁性層の剥離層、マスク層及びレジスト層で覆われていない箇所をイオンエッチングにより除去した。イオンエッチングの条件は、窒素ガスを１０ｓｃｃｍ、圧力を０．１Ｐａ、高周波プラズマ電力を３００Ｗ、ＤＣバイアスを３０Ｗ、エッチング時間を３０秒とした。このとき、記録磁性層に形成される凹部の深さは約１０ｎｍであった。また、記録磁性層の凹部では、底面から深さ約５ｎｍの領域が窒素原子のイオン注入により非磁性化していた。 Next, portions of the recording magnetic layer not covered with the release layer, mask layer, and resist layer were removed by ion etching. The ion etching conditions were as follows: nitrogen gas was 10 sccm, pressure was 0.1 Pa, high-frequency plasma power was 300 W, DC bias was 30 W, and etching time was 30 seconds. At this time, the depth of the recess formed in the recording magnetic layer was about 10 nm. In addition, in the concave portion of the recording magnetic layer, a region having a depth of about 5 nm from the bottom surface was made nonmagnetic by ion implantation of nitrogen atoms.
　次に、剥離層を還元除去し、この剥離層をレジスト層及びマスク層と共に磁性層上から除去した。この還元条件は、水素ガスを４０ｓｃｃｍ、圧力を０．３Ｐａ、高周波プラズマ電力を３００Ｗ、ＤＣバイアスを３０Ｗ、曝露時間を３０秒とした。その後、イオンミリング装置により、アルゴンガスを１０ｓｃｃｍ、圧力を０．５Ｐａ、エッチング時間を５秒として、記録磁性層の表面を約１～２ｎｍの範囲でエッチングした。 Next, the release layer was reduced and removed, and the release layer was removed from the magnetic layer together with the resist layer and the mask layer. The reduction conditions were hydrogen gas of 40 sccm, pressure of 0.3 Pa, high-frequency plasma power of 300 W, DC bias of 30 W, and exposure time of 30 seconds. Thereafter, the surface of the recording magnetic layer was etched in the range of about 1 to 2 nm by an ion milling apparatus with an argon gas of 10 sccm, a pressure of 0.5 Pa, and an etching time of 5 seconds.
　次に、記録磁性層の表面にＣＶＤ法にてカーボン保護膜を５ｎｍ成膜し、その後、フッ素系潤滑剤を２．０ｎｍ塗布して磁気記録媒体を製造した。 Next, a carbon protective film having a thickness of 5 nm was formed on the surface of the recording magnetic layer by a CVD method, and then a fluorine-based lubricant was applied to 2.0 nm to produce a magnetic recording medium.
　以上の方法で製造した磁気記録媒体の電磁変換特性を測定した。電磁変換特性の評価は、スピンスタンドを用いて実施した。このとき、評価用のヘッドには、記録には垂直記録ヘッド、読み込みにはＴｕＭＲヘッドを用いた。そして、７５０ｋＦＣＩの信号を記録したときのＳＮＲを測定した。その結果、実施例１では、ＳＮＲが１６．２ｄＢであった。 The electromagnetic conversion characteristics of the magnetic recording medium manufactured by the above method were measured. The evaluation of electromagnetic conversion characteristics was performed using a spin stand. At this time, as the evaluation head, a perpendicular recording head was used for recording and a TuMR head was used for reading. Then, the SNR when a 750 kFCI signal was recorded was measured. As a result, in Example 1, the SNR was 16.2 dB.
（実施例２）
　実施例２では、マスク層にＳＯＧを使用し、レジスト層を設けなかった。すなわち、剥離層となるノボラック樹脂膜の上に、ＳＯＧをスピンコート法により塗布し、層厚１００ｎｍのマスク層を形成した。そして、磁気記録パターンのポジパターンを有するガラス製のスタンプを用いて、このスタンプを１ＭＰａ（約８．８ｋｇｆ／ｃｍ２）の圧力でマスク層に押し付けた状態で、１５０Ｗの熱線を１０秒間照射し、マスク層を硬化させた。その後、スタンプをマスク層から分離し、マスク層に磁気記録パターンに対応した凹凸パターンを転写した。 (Example 2)
In Example 2, SOG was used for the mask layer, and no resist layer was provided. That is, SOG was applied by spin coating on a novolac resin film to be a release layer to form a mask layer having a layer thickness of 100 nm. Then, using a glass stamp having a positive pattern of the magnetic recording pattern, a 150 W heat ray was irradiated for 10 seconds with this stamp pressed against the mask layer at a pressure of 1 MPa (about 8.8 kgf / cm 2 ). The mask layer was cured. Thereafter, the stamp was separated from the mask layer, and an uneven pattern corresponding to the magnetic recording pattern was transferred to the mask layer.
　次に、マスク層の凹部の箇所をドライエッチングで除去した。ドライエッチングの条件は、アルゴンガスを４０ｓｃｃｍ、圧力を０．３Ｐａ、高周波プラズマ電力を３００Ｗ、ＤＣバイアスを３０Ｗ、エッチング時間を１５秒とした。 Next, the concave portion of the mask layer was removed by dry etching. The dry etching conditions were argon gas of 40 sccm, pressure of 0.3 Pa, high frequency plasma power of 300 W, DC bias of 30 W, and etching time of 15 seconds.
　次に、記録磁性層のマスク層で覆われていない箇所をイオンエッチングにより除去した。イオンエッチングの条件は、窒素ガスを１０ｓｃｃｍ、圧力を０．１Ｐａ、高周波プラズマ電力を１５０Ｗ、ＤＣバイアスを３０Ｗ、エッチング時間を５０秒とした。 Next, the portion of the recording magnetic layer not covered with the mask layer was removed by ion etching. The ion etching conditions were as follows: nitrogen gas was 10 sccm, pressure was 0.1 Pa, high-frequency plasma power was 150 W, DC bias was 30 W, and etching time was 50 seconds.
　次に、マスク層をドライエッチングにより除去した。ドライエッチングの条件は、水素ガスを４０ｓｃｃｍ、圧力を０．３Ｐａ、高周波プラズマ電力を３００Ｗ、ＤＣバイアスを３０Ｗ、エッチング時間を３０秒とした。 Next, the mask layer was removed by dry etching. The dry etching conditions were as follows: hydrogen gas was 40 sccm, pressure was 0.3 Pa, high-frequency plasma power was 300 W, DC bias was 30 W, and etching time was 30 seconds.
　それ以外は、実施例１と同様の条件で磁気記録媒体を製造した。その結果、実施例２では、ＳＮＲが１６．３ｄＢであった。 Other than that, a magnetic recording medium was manufactured under the same conditions as in Example 1. As a result, in Example 2, the SNR was 16.3 dB.
（比較例１）
　比較例１では、レジスト層及びマスク層の除去を、酸素プラズマを用いたドライエッチングにより行った。このドライエッチングの条件は、酸素ガスを４０ｓｃｃｍ、圧力を０．３Ｐａ、高周波プラズマ電力を３００Ｗ、ＤＣバイアスを３０Ｗ、エッチング時間を２０秒とした。 (Comparative Example 1)
In Comparative Example 1, the resist layer and the mask layer were removed by dry etching using oxygen plasma. The dry etching conditions were oxygen gas of 40 sccm, pressure of 0.3 Pa, high-frequency plasma power of 300 W, DC bias of 30 W, and etching time of 20 seconds.
　それ以外は、実施例１と同様の条件で磁気記録媒体を製造した。その結果、比較例１では、ＳＮＲが１５．６ｄＢであった。 Other than that, a magnetic recording medium was manufactured under the same conditions as in Example 1. As a result, in Comparative Example 1, the SNR was 15.6 dB.
（比較例２）
　比較例２では、レジスト層及びマスク層の除去を、窒素プラズマを用いたドライエッチングにより行った。このドライエッチングの条件は、窒素ガスを４０ｓｃｃｍ、圧力を０．３Ｐａ、高周波プラズマ電力を３００Ｗ、ＤＣバイアスを３０Ｗ、エッチング時間を２５秒とした。 (Comparative Example 2)
In Comparative Example 2, the resist layer and the mask layer were removed by dry etching using nitrogen plasma. The dry etching conditions were as follows: nitrogen gas was 40 sccm, pressure was 0.3 Pa, high-frequency plasma power was 300 W, DC bias was 30 W, and etching time was 25 seconds.
　それ以外は、実施例１と同様の条件で磁気記録媒体を製造した。その結果、比較例２では、ＳＮＲが１５．７ｄＢであった。 Other than that, a magnetic recording medium was manufactured under the same conditions as in Example 1. As a result, in Comparative Example 2, the SNR was 15.7 dB.
（比較例３）
　比較例３では、レジスト層及びマスク層の除去を、ハロゲンプラズマを用いたドライエッチングにより行った。このドライエッチングの条件は、ＣＦ４ガスを４０ｓｃｃｍ、圧力を０．３Ｐａ、高周波プラズマ電力を３００Ｗ、ＤＣバイアスを３０Ｗ、エッチング時間を１５秒とした。 (Comparative Example 3)
In Comparative Example 3, the resist layer and the mask layer were removed by dry etching using halogen plasma. The dry etching conditions were CF 4 gas of 40 sccm, pressure of 0.3 Pa, high-frequency plasma power of 300 W, DC bias of 30 W, and etching time of 15 seconds.
　それ以外は、実施例１と同様の条件で磁気記録媒体を製造した。その結果、比較例３では、ＳＮＲが１５．１ｄＢであった。 Other than that, a magnetic recording medium was manufactured under the same conditions as in Example 1. As a result, in Comparative Example 3, the SNR was 15.1 dB.
　１…非磁性基板　２…磁性層　２ａ，２ｂ…磁気記録パターン　３…剥離層　４…マスク層　５…レジスト層　６…保護層　７…凹部　８…改質部
　３０…磁気記録媒体　５１…回転駆動部　５２…磁気ヘッド　５３…ヘッド駆動部　５４…記録再生信号処理系 DESCRIPTION OF SYMBOLS 1 ... Nonmagnetic board | substrate 2 ... Magnetic layer 2a, 2b ... Magnetic recording pattern 3 ... Release layer 4 ... Mask layer 5 ... Resist layer 6 ... Protective layer 7 ... Recessed part 8 ... Modification part 30 ... Magnetic recording medium 51 ... Rotation drive part 52 ... Magnetic head 53 ... Head drive unit 54 ... Recording / reproduction signal processing system

Claims (5)

  1. 　磁気的に分離された磁気記録パターンを有する磁気記録媒体の製造方法であって、
    　非磁性基板の少なくとも一方の面上に磁性層を形成する工程と、
    　前記磁性層の上に剥離層を形成する工程と、
    　前記剥離層の上にマスク層を形成する工程と、
    　前記マスク層及び剥離層を前記磁気記録パターンに対応した形状にパターニングする工程と、
    　前記磁性層の前記マスク層及び剥離層で覆われていない箇所を部分的に改質又は除去する工程と、
    　前記マスク層及び剥離層を前記磁性層の上から除去する工程とを含み、
    　前記マスク層及び剥離層を除去する際に、実質的に酸素、窒素、ハロゲンを含まない還元性のガスを用いて前記剥離層を還元除去することによって、この剥離層と共に前記マスク層を前記磁性層の上から除去することを特徴とする磁気記録媒体の製造方法。     A method for producing a magnetic recording medium having a magnetically separated magnetic recording pattern, comprising:
    Forming a magnetic layer on at least one surface of the nonmagnetic substrate;
    Forming a release layer on the magnetic layer;
    Forming a mask layer on the release layer;
    Patterning the mask layer and the release layer into a shape corresponding to the magnetic recording pattern;
    A step of partially modifying or removing a portion of the magnetic layer not covered with the mask layer and the release layer;
    Removing the mask layer and the release layer from above the magnetic layer,
    When removing the mask layer and the release layer, the release layer is reduced and removed using a reducing gas that substantially does not contain oxygen, nitrogen, or halogen, so that the mask layer and the release layer are magnetically removed. A method of manufacturing a magnetic recording medium, comprising removing the layer from above.
  2. 　前記マスク層をパターニングする前に、当該マスク層の上に前記磁気記録パターンに対応した形状にパターニングされたレジスト層を形成する工程を含み、
    　前記レジスト層を用いて前記マスク層を前記磁気記録パターンに対応した形状にパターニングし、前記パターニングされたマスク層を用いて前記磁性層を部分的に改質又は除去した後、前記還元性のガスを用いて前記剥離層を還元除去することによって、この剥離層と共に前記マスク層及びレジスト層を前記磁性層の上から除去することを特徴とする請求項１に記載の磁気記録媒体の製造方法。     Forming a resist layer patterned into a shape corresponding to the magnetic recording pattern on the mask layer before patterning the mask layer;
    After patterning the mask layer into a shape corresponding to the magnetic recording pattern using the resist layer and partially modifying or removing the magnetic layer using the patterned mask layer, the reducing gas is used. 2. The method of manufacturing a magnetic recording medium according to claim 1, wherein the mask layer and the resist layer are removed together with the release layer from the top of the magnetic layer by reducing and removing the release layer using an adhesive.
  3. 　前記剥離層として、ノボラック樹脂を用いることを特徴とする請求項１に記載の磁気記録媒体の製造方法。 2. The method of manufacturing a magnetic recording medium according to claim 1, wherein a novolac resin is used as the release layer.
  4. 　前記還元性のガスとして、水素を用いることを特徴とする請求項１に記載の磁気記録媒体の製造方法。 2. The method of manufacturing a magnetic recording medium according to claim 1, wherein hydrogen is used as the reducing gas.
  5. 　請求項１～４の何れか一項に記載の製造方法により製造された磁気記録媒体と、
    　前記磁気記録媒体を記録方向に駆動する媒体駆動部と、
    　前記磁気記録媒体に対する記録動作と再生動作とを行う磁気ヘッドと、
    　前記磁気ヘッドを磁気記録媒体に対して相対移動させるヘッド移動手段と、
    　前記磁気ヘッドへの信号入力と前記磁気ヘッドから出力信号の再生とを行うための記録再生信号処理手段とを備えることを特徴とする磁気記録再生装置。     A magnetic recording medium manufactured by the manufacturing method according to any one of claims 1 to 4,
    A medium driving unit for driving the magnetic recording medium in a recording direction;
    A magnetic head for performing a recording operation and a reproducing operation on the magnetic recording medium;
    Head moving means for moving the magnetic head relative to a magnetic recording medium;
    A magnetic recording / reproducing apparatus comprising: a recording / reproducing signal processing means for inputting a signal to the magnetic head and reproducing an output signal from the magnetic head.
PCT/JP2011/050519 2010-01-18 2011-01-14 Magnetic recording medium manufacturing method and magnetic read/write device WO2011087078A1 (en)

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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008065944A (en) * 2006-09-08 2008-03-21 Ulvac Japan Ltd Forming method of pattern of magnetic layer, manufacturing method of magnetoresistive element, and manufacturing method of magnetic storage medium
JP2008090881A (en) * 2006-09-29 2008-04-17 Tdk Corp Manufacturing method of magnetic recording medium
JP2009283076A (en) * 2008-05-22 2009-12-03 Tdk Corp Stamper, irregular pattern formation method, and manufacturing method of information recording medium

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008065944A (en) * 2006-09-08 2008-03-21 Ulvac Japan Ltd Forming method of pattern of magnetic layer, manufacturing method of magnetoresistive element, and manufacturing method of magnetic storage medium
JP2008090881A (en) * 2006-09-29 2008-04-17 Tdk Corp Manufacturing method of magnetic recording medium
JP2009283076A (en) * 2008-05-22 2009-12-03 Tdk Corp Stamper, irregular pattern formation method, and manufacturing method of information recording medium

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