WO2010058792A1 - Method for manufacturing magnetic storage medium, magnetic storage medium, and information storage device - Google Patents

Method for manufacturing magnetic storage medium, magnetic storage medium, and information storage device Download PDF

Info

Publication number
WO2010058792A1
WO2010058792A1 PCT/JP2009/069560 JP2009069560W WO2010058792A1 WO 2010058792 A1 WO2010058792 A1 WO 2010058792A1 JP 2009069560 W JP2009069560 W JP 2009069560W WO 2010058792 A1 WO2010058792 A1 WO 2010058792A1
Authority
WO
WIPO (PCT)
Prior art keywords
magnetic
storage medium
film
manufacturing
ion implantation
Prior art date
Application number
PCT/JP2009/069560
Other languages
French (fr)
Japanese (ja)
Inventor
賢治 佐藤
努 田中
拓也 渦巻
勉 西橋
正 森田
一弘 渡辺
Original Assignee
株式会社アルバック
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 株式会社アルバック filed Critical 株式会社アルバック
Publication of WO2010058792A1 publication Critical patent/WO2010058792A1/en

Links

Images

Classifications

    • 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

  • This case relates to a manufacturing method for manufacturing a magnetic storage medium, a magnetic storage medium, and an information storage device including the magnetic storage medium.
  • HDDs Hard disk drives
  • mass storage devices capable of high-speed data access and high-speed transfer.
  • the surface recording density has been increasing at a high annual rate so far, and further improvement in recording density is still required.
  • This interference is a generic term for a phenomenon in which magnetic recording information is overwritten on a non-target adjacent track during recording, or a phenomenon in which crosstalk occurs due to a leakage magnetic field from a non-target adjacent track during reproduction. It is a thing. These phenomena all cause a decrease in the S / N ratio of the reproduction signal, and cause a deterioration in error rate.
  • Discrete track type magnetic storage media and bit patterned magnetic storage media have been proposed as a method for realizing a short bit length and high track density by avoiding these interference and thermal fluctuation phenomena (for example, patents).
  • Reference 1 Discrete track type magnetic storage media and bit patterned magnetic storage media have been proposed as a method for realizing a short bit length and high track density by avoiding these interference and thermal fluctuation phenomena.
  • bit-patterned magnetic storage media the positions of recording bits are determined in advance, magnetic material dots are formed at the determined recording bit positions, and the dots are made of a non-magnetic material. The When the dots of the magnetic material are separated from each other in this way, the magnetic interaction between the dots is small, and the above-described interference and thermal fluctuation phenomenon are avoided.
  • Patent Document 1 As a manufacturing method of the bit patterned magnetic storage medium, a conventional manufacturing method proposed in Patent Document 1 will be described.
  • FIG. 1 is a diagram showing a conventional manufacturing method of a bit patterned magnetic storage medium.
  • the magnetic film 2 is formed on the substrate 1 in the film forming step (A).
  • a resist 3 made of an ultraviolet curable resin is applied on the magnetic film 2, and a mold 4 having nano-sized holes 4 a is placed on the resist 3.
  • the resist 3 enters the nano-sized hole 4a, and the dots 3a of the resist 3 are formed.
  • the resist 3 is irradiated with ultraviolet rays through the mold 4, so that the resist 3 is cured and the dots 3 a are printed on the magnetic film 2. Further, after the resist 3 is cured, the mold 4 is removed.
  • etching is performed in the etching step (C), so that the magnetic film is removed leaving the magnetic dots 2 a protected by the dots 3 a of the resist 3.
  • the dots 3 a of the resist 3 are removed by chemical treatment, and only the magnetic dots 2 a remain on the substrate 1.
  • the space between the magnetic dots 2a is filled with a nonmagnetic material. Thereafter, the surface is flattened through a flattening step (E), whereby the bit patterned magnetic storage medium 6 is completed (F).
  • ions are implanted to change the magnetic characteristics, so that complicated manufacturing processes such as etching, filling, and flattening are not required, and an increase in manufacturing cost can be significantly suppressed.
  • bit patterned magnetic storage medium As an example.
  • such a problem is not limited to the bit-patterned magnetic storage medium, and is also a problem that applies to, for example, a discrete track magnetic storage medium. That is, such a problem is commonly applied to a magnetic storage medium of a type including a magnetic part in which information is magnetically recorded and a low magnetic part having a saturation magnetization smaller than the saturation magnetization of the magnetic part. It is.
  • an object of the present application is to provide a simple manufacturing method capable of manufacturing a magnetic storage medium of the above type, and a magnetic storage medium and an information storage device of the above type that can be manufactured by such a simple manufacturing method. To do.
  • a magnetic storage medium manufacturing method of a basic form for achieving the above object is A magnetic film forming process of forming a magnetic film with an Sm—Co based alloy;
  • the magnetic film includes an ion implantation process in which ions are locally implanted into other regions excluding a predetermined protective region.
  • a magnetic storage medium of a basic form that achieves the above object is A substrate, A magnetic part provided on the substrate and having a magnetic film formed of an Sm—Co alloy and on which information is magnetically recorded; And a low magnetic part having a film to be implanted in which ions are implanted into a magnetic film continuous with the magnetic film of the magnetic part and having a saturation magnetization smaller than the saturation magnetization of the magnetic part.
  • An information storage device of a basic form that achieves the above object, A substrate, a magnetic part provided on the substrate and having a magnetic film formed of an Sm—Co alloy on the substrate, on which information is magnetically recorded, and a magnetic part continuous with the magnetic film of the magnetic part
  • a magnetic storage medium comprising a film to be implanted in which ions are implanted into the film and a low magnetic part having a saturation magnetization smaller than the saturation magnetization of the magnetic part;
  • a magnetic head that magnetically records and / or reproduces information on a magnetic part in proximity to or in contact with the magnetic storage medium;
  • a head position control mechanism that moves the magnetic head relative to the surface of the magnetic storage medium and positions the magnetic head on a magnetic portion that records and / or reproduces information by the magnetic head. It is characterized by that.
  • the magnetic storage medium manufacturing method of the above basic form for example, a low magnetic portion that occupies between magnetic dots of a bit patterned magnetic storage medium, or a low occupancy of both sides of a track of a discrete track magnetic storage medium
  • the magnetic part can be formed by ion implantation. This eliminates the need for complicated manufacturing processes such as etching, filling, and planarization, so that the magnetic storage medium manufacturing method of this basic form is a simple manufacturing method. Further, according to the magnetic storage medium and the information storage device of the above basic form, it is possible to manufacture with the simple manufacturing method.
  • the magnetic film that receives the ion implantation is formed of an Sm—Co based alloy.
  • the saturation magnetization can be sufficiently reduced by ion implantation while ensuring the magnetic anisotropy necessary for magnetic recording with magnetic dots.
  • a bit patterned type or discrete track type magnetic storage medium or information storage device is realized by the above-described simple manufacturing method that locally reduces the saturation magnetization of the magnetic film. Can be manufactured.
  • a simple manufacturing method capable of manufacturing the above type of magnetic storage medium, and the above type of magnetic storage medium and information storage device that can be manufactured by such a simple manufacturing method are obtained. be able to.
  • FIG. 3 is a perspective view schematically showing the structure of the magnetic disk shown in FIG. 2. It is a figure which shows the manufacturing method of the magnetic disc shown in FIG. 2 and FIG. It is a figure which shows a structure common to 1st Example, 2nd Example, and a comparative example. 5 is a graph showing the film thickness dependence of the magnetic anisotropy field in each of a magnetic film of Sm—Co alloy and a magnetic film of Co—Cr—Pt alloy.
  • FIG. 2 is a diagram showing an internal structure of a hard disk device (HDD) which is a specific embodiment of the information storage device.
  • HDD hard disk device
  • the hard disk device (HDD) 100 shown in this figure is incorporated in a host device such as a personal computer and used as information storage means in the host device.
  • a disk-shaped magnetic disk 10 is housed in a plurality of housings H so as to overlap in the depth direction of the figure.
  • the magnetic disk 10 corresponds to a specific embodiment of the magnetic storage medium whose basic form has been described above.
  • the magnetic part is a plurality of magnetic dots regularly arranged on the substrate, and information is magnetically recorded on each.
  • An application mode in which the low magnetic part is an interdot separation band provided between the magnetic dots and hindering magnetic coupling between the magnetic dots is preferable.
  • This application form corresponds to a bit patterned magnetic storage medium in which magnetic dots on which bit information is recorded are provided in advance on each substrate. Since the bit-patterned magnetic storage medium effectively avoids interference and thermal fluctuation phenomena as described above, the above-described applied form corresponding to such a type of magnetic storage medium is preferable.
  • the magnetic disk 10 in FIG. 2 is a bit-patterned magnetic storage medium and corresponds to a specific embodiment of this application form.
  • the magnetic disk 10 is also a so-called perpendicular magnetic storage medium in which information is recorded in each magnetic dot with a magnetic pattern formed by magnetization in a direction perpendicular to the front and back surfaces.
  • the present invention is also applicable to a so-called in-plane magnetic storage medium in which information is recorded with a magnetic pattern formed by longitudinal magnetization on the front and back surfaces.
  • the magnetic disk 10 rotates around the disk shaft 11 in the housing H.
  • a swing arm 20 that moves along the surface of the magnetic disk 10
  • an actuator 30 that is used to drive the swing arm 20
  • a control circuit 50 are also housed.
  • the swing arm 20 holds a magnetic head 21 for writing and reading information on the magnetic disk 10 at the tip.
  • the swing arm 20 is rotatably supported by the housing H by a bearing 24.
  • the swing arm 20 rotates within a range of a predetermined angle about the bearing 24 to move the magnetic head 21 along the surface of the magnetic disk 10.
  • This magnetic head corresponds to an example of the magnetic head in the basic form of the information storage device described above.
  • the reading and writing of information by the magnetic head 21 and the movement of the arm 30 are controlled by the control circuit 50, and information exchange with the host device is also performed through this control circuit 50.
  • a combination of the swing arm 20, the bearing 24, the actuator 30, and the control circuit 50 corresponds to an example of a head position control mechanism in the basic form of the information storage device described above.
  • FIG. 3 is a perspective view schematically showing the structure of the magnetic disk shown in FIG.
  • FIG. 3 shows a part cut out from a disk-shaped magnetic disk.
  • the magnetic disk 10 shown in FIG. 3 has a structure in which a plurality of magnetic dots Q are arranged on a substrate S in a regular arrangement. Information corresponding to 1 bit is magnetically recorded on each magnetic dot Q.
  • the magnetic dots Q are arranged in a circle around the center of the magnetic disk 10, and the row of magnetic dots forms a track T.
  • substrate S is corresponded to an example of the board
  • the magnetic dot Q corresponds to an example of the magnetic portion in the basic form described above, and also corresponds to an example of the magnetic dot in the applied form described above corresponding to the bit patterned magnetic storage medium.
  • the saturation magnetization is lower than the saturation magnetization of the magnetic dots Q, and an interdot separation zone U that magnetically divides between the magnetic dots Q is formed. Due to the interdot dot U, the magnetic interaction between the magnetic dots Q is reduced.
  • the interdot dot band U corresponds to an example of the low magnetic part in the basic mode described above, and also corresponds to an example of the interdot dot band in the application mode described above corresponding to the bit patterned magnetic storage medium. .
  • the magnetic interaction between the magnetic dots Q is small, the magnetic interaction between the tracks T is small even when information is recorded on and reproduced from the magnetic dots Q, so that there is little so-called interference between the tracks. Further, in each magnetic dot Q, the boundary of recorded information bits does not fluctuate due to heat, and so-called thermal fluctuation phenomenon is avoided. Therefore, according to the bit patterned magnetic disk 10 as shown in FIG. 3, the track width can be reduced and the recording bit length can be reduced, and a magnetic recording medium having a high recording density can be realized.
  • a method for manufacturing the magnetic disk 10 will be described below.
  • the manufacturing method of the magnetic disk 10 corresponds to a specific embodiment of the magnetic storage medium manufacturing method described above with respect to the basic mode.
  • the ion implantation process is a process in which ions are locally implanted between the plurality of locations using a plurality of locations regularly arranged in the direction in which the magnetic film spreads as the protective region.”
  • the application form is suitable.
  • This application form corresponds to a magnetic storage medium manufacturing method for manufacturing a bit patterned magnetic storage medium. Since the bit-patterned magnetic storage medium effectively avoids interference and thermal fluctuation as described above, the above-described application form for manufacturing such a type of magnetic storage medium is preferable.
  • the method of manufacturing the magnetic disk 10 described below corresponds to a specific embodiment of this application mode.
  • FIG. 4 is a diagram showing a method of manufacturing the magnetic disk shown in FIGS.
  • the magnetic film 62 is formed on the glass substrate 61 in the film forming step (A).
  • This film forming step (A) corresponds to an example of a magnetic film forming process in the basic form of the magnetic storage medium manufacturing method described above, and this magnetic film 62 is a magnetic film formed of an Sm—Co alloy.
  • saturation magnetization in a region corresponding to the interdot separation band U of FIG. 3 in the magnetic film 62 is reduced by ion implantation in an ion implantation step (C) described later.
  • C ion implantation step
  • the saturation magnetization is reduced to approximately 20% before ion implantation.
  • magnetic recording with the magnetic dots Q generally requires a magnetic anisotropy of 14 kOe or more in a magnetic anisotropic magnetic field.
  • the magnetic anisotropy of the magnetic dots Q is the magnetic anisotropy of the magnetic film 62
  • the magnetic anisotropy of 14 kOe or more is required in the magnetic film 62.
  • the developer of this case forms a magnetic film with a film thickness of about 5 nm, It has been discovered that both a magnetic anisotropy of 14 kOe or more and a sufficient reduction in saturation magnetization can be achieved.
  • the magnetic film 62 is formed of an Sm—Co alloy having such desirable characteristics with a thickness of about 5 nm.
  • a resist 63 made of an ultraviolet curable resin is applied on the magnetic film 62, and a mold 64 with nano-sized holes 64 a is placed on the resist 63.
  • the resist 63 enters the nano-sized hole 64a, and the dots 63a of the resist 63 are formed.
  • the resist 63 is irradiated with ultraviolet rays through the mold 64, so that the resist 63 is cured and the dots 63 a are printed on the magnetic film 62. Further, the mold 64 is removed after the resist 63 is cured.
  • the process proceeds to the ion implantation process (C).
  • this ion implantation step (C) either one of oxygen ions and nitrogen ions is irradiated from above the magnetic film 62 on which the dots 63a are printed. As a result, ions are implanted into the magnetic film 62 leaving the magnetic dots 62a protected by the dots 63a of the resist 63, and the saturation magnetization is reduced to 20% before the implantation.
  • This ion implantation step (C) corresponds to an example of the ion implantation step in the basic form described above.
  • This ion implantation step (C) also corresponds to an example of an ion implantation process in the above-described applied mode corresponding to the manufacture of a bit patterned magnetic storage medium.
  • the ion implantation process is a process using one of oxygen ions and nitrogen ions as the ions” is preferable.
  • the developer of this case has discovered that oxygen ions and nitrogen ions can effectively degrade the magnetic properties of a magnetic film formed of an Sm—Co based alloy.
  • This application form is based on this discovery and can be said to be suitable.
  • the ion implantation process (C) in FIG. 4 corresponds to an example of an ion implantation process in this application mode.
  • “It further includes a mask forming process for forming a mask on the magnetic film that inhibits ion implantation into the protective region,
  • a mask forming process for forming a mask on the magnetic film that inhibits ion implantation into the protective region.
  • ions are applied from above the magnetic film on which the mask is formed, so that the ions are locally implanted into other regions except for the protection region protected by the mask.
  • An application form of “some” is also suitable.
  • the nanoimprint process (B) in FIG. 4 corresponds to an example of a mask formation process in this application form
  • the ion implantation process (C) corresponds to an example of an ion implantation process in this application form.
  • the mask forming process is a process of forming the mask with a resist
  • An application form that “the mask forming process is a process of forming the mask with a resist by a nanoimprint process” is more preferable.
  • Resist mask formation is technically stable and accurate mask formation can be expected, and nanoimprint process mask formation is preferable because it can easily create a nano-level mask pattern.
  • the nanoimprint process (B) shown in FIG. 4 also corresponds to an example of a mask formation process in these more preferable applications.
  • the resist is not completely removed even at the location where ions are to be implanted.
  • ions pass through the resist and are injected into the magnetic film 62, and when the resist is thick (that is, where the dots 63a are formed), the ions stop at the resist and do not reach the magnetic film. Therefore, a desired track pattern can be formed.
  • the acceleration voltage of ions is set so that ions are implanted into the central portion of the magnetic film 62.
  • This acceleration voltage varies depending on the ion species, and also varies depending on the depth to the center of the magnetic film and the material.
  • an interdot separation band 62b for separating the magnetic interaction between the magnetic dots 62a is formed between the magnetic dots 62a, and a bit patterned magnetic field is formed.
  • the storage medium 10 is completed (D). Since the saturation magnetization in the interdot separation band 62b is sufficiently lower than the saturation magnetization of the magnetic dot 62a, information is recorded only on the magnetic dot 62a, and no information is recorded in the interdot separation band 62b.
  • the smoothness of the magnetic dots 62a and the interdot separation bands 62b constituting the surface is the magnetic film formed in the film forming step (A).
  • the smoothness at 62 is maintained as it is. Therefore, the planarization step as in the prior art shown in FIG. 1 is not necessary, and the manufacturing method shown in FIG. 4 is a simple method.
  • the magnetic dots 62 a are protected by the resist dots 63 a printed on the magnetic film 62. Accordingly, the entire surface of the magnetic storage medium 10 can be irradiated with ions at the same time, and ion implantation to a required portion can be sufficiently realized by ion irradiation for several seconds, so that mass productivity is not impaired.
  • FIG. 5 is a diagram showing a structure common to the first example, the second example, and the comparative example.
  • a well-cleaned glass substrate 70 was set in a magnetron sputtering apparatus and evacuated to 5 ⁇ 10 ⁇ 5 Pa or less. Thereafter, (111) crystal-oriented fcc-Cu was formed in a thickness of 5 nm as an underlayer 71 for crystal orientation of the magnetic layer without heating the glass substrate 70 at an Ar gas pressure of 0.67 Pa. .
  • the process of forming the underlayer 71 is not described in the manufacturing method shown in FIG.
  • the magnetic film 72 was formed with a film thickness in the range of 3 nm or more and less than 10 nm.
  • the magnetic anisotropy magnetic field in the thickness direction was measured for each film thickness 72 within the above range using SQID (Superducting Quantum Interference Device). By this measurement, the film thickness dependence of the magnetic anisotropic magnetic field was obtained for the magnetic film 72 of the Sm—Co alloy.
  • a resist is applied on the protective layer 73, and a columnar resist pattern 74 having a diameter of 20 nm to 60 nm and a height of about 50 nm is applied using a nanoimprint process. Formed.
  • the saturation magnetization of the magnetic film 72 before ion implantation is measured in advance, and the saturation magnetization lowered by receiving the ion implantation is measured every time the ion implantation is performed within the above range.
  • the ratio of the latter to the former was obtained.
  • the dependence of the saturation magnetization reduction effect due to the implantation of nitrogen ions 75 on the ion implantation amount was obtained for the magnetic film 72.
  • the resist pattern 74 was removed by SCl cleaning.
  • a magnetic film 72 having a thickness of 5 nm was prepared by implanting oxygen ions.
  • the process was performed under the same conditions as in the first embodiment except that the magnetic film 72 had a thickness of only 5 nm and the ion species of the implanted ions were oxygen ions. .
  • the measurement related to the ion implantation amount dependency of the saturation magnetization reduction effect by oxygen ion implantation was performed.
  • FIG. 6 is a graph showing the film thickness dependence of the magnetic anisotropy field in each of the Sm—Co alloy magnetic film and the Co—Cr—Pt alloy magnetic film.
  • the horizontal axis represents the film thickness of the magnetic film
  • the vertical axis represents the magnetic anisotropic magnetic field.
  • the film thickness dependence of the magnetic anisotropy field in the magnetic film 72 of the Sm—Co alloy is indicated by a first line L1 connecting circles.
  • the film thickness dependence of the magnetic anisotropy field in the magnetic film 72 of the Co—Cr—Pt alloy is shown by the second line L2 connecting the square marks.
  • the magnetic film of the Co—Cr—Pt alloy may require a film thickness of 10 nm or more in order to obtain a magnetic anisotropic magnetic field of 14 kOe or more required for magnetic recording.
  • a magnetic anisotropy magnetic field of 14 kOe or more can be obtained even with a film thickness of 5 nm or less in the magnetic film of Sm 17 —Co 83 alloy.
  • a magnetic anisotropic magnetic field of 14 kOe or more is secured by forming with a film thickness of 5 nm. It is shown that the saturation magnetization of the magnetic film can be sufficiently reduced. Note that, as described above, in order to form an interdot separation band that magnetically and reliably divides between magnetic dots in a bit patterned magnetic storage medium, the saturation magnetization is about 20 before ion implantation. % Is desirable.
  • FIG. 7 is a graph showing the dependency of the saturation magnetization reduction effect by ion implantation on the ion implantation amount for the first example
  • FIG. 8 is the ion of the saturation magnetization reduction effect by ion implantation for the second example. It is a graph which shows injection amount dependence.
  • the horizontal axis represents the ion implantation amount
  • the vertical axis represents the normalized saturation magnetization.
  • the normalized saturation magnetization on the vertical axis is indicated by the ratio of the saturation magnetization after ion implantation to the saturation magnetization before ion implantation.
  • the saturation magnetization of the magnetic film of the Sm 17 —Co 83 alloy having a film thickness of 5 nm and an ion implantation amount of 2 ⁇ 10 16 atoms / cm 2 is obtained for both nitrogen ions and oxygen ions. It can be seen that it can be reduced to 20% or less before the injection. In general, in ion implantation, it is said that the ion implantation amount is desirably 1 ⁇ 10 17 atoms / cm 2 or less in order not to impair the surface state of the magnetic film.
  • the saturation magnetization can be reduced with a sufficient margin with respect to the upper limit of 1 ⁇ 10 17 atoms / cm 2 by implanting nitrogen ions or oxygen ions into the magnetic film of the Sm 17 —Co 83 alloy. I understand.
  • the saturation magnetization can be sufficiently reduced while obtaining a magnetic anisotropic magnetic field of 14 kOe or more necessary for magnetic recording when the film thickness is 5 nm. confirmed. Therefore, according to the above-described manufacturing method employing the Sm—Co alloy as a magnetic material, a bit patterned type or discrete track type magnetic storage medium or information storage device can be easily and practically used by using an ion doping method. Can be manufactured.
  • a bit patterned magnetic storage medium is illustrated as an example of the magnetic storage medium.
  • the magnetic storage medium is not limited to this, and may be, for example, a discrete track type.
  • the Sm—Co alloy is exemplified as an example of the Sm—Co based alloy forming the magnetic film, but the Sm—Co based alloy is not limited to this.
  • the Sm—Co based alloy may be an alloy in which other elements are added to the Sm—Co alloy within a composition range that does not impair the magnetic properties of the Sm—Co alloy.
  • a resist pattern as a preferred mask for forming magnetic dots is exemplified.
  • a process in which a stencil mask is arranged on the very surface of the medium so as not to contact the medium surface may be used. According to this process, the steps of resist coating and resist removal can be omitted.
  • the nanoimprint process is shown to be used as the best example of resist patterning.
  • electron beam exposure may be used for patterning.

Abstract

Provided are a simple manufacturing method by which bit-patterned, discrete track, and other types of magnetic storage media can be manufactured, magnetic storage media of such types which can be manufactured by such simple manufacturing method, and an information storage device.  A magnetic disc (10) is manufactured by a manufacturing method having a film-forming step (A) which forms a magnetic film (62) composed of an Sm-Co alloy on a substrate (61), and an ion implanting step (C) which locally implants ion into other areas of the magnetic film (62) besides the plurality of areas that form the magnetic dots where information is magnetically recorded in, and lowers the saturation magnetization thereof to thereby form,  between the magnetic dots, a dot separating strip having saturation magnetization smaller than the saturation magnetization of the magnetic dots.

Description

磁気記憶媒体製造方法、磁気記憶媒体、および情報記憶装置Magnetic storage medium manufacturing method, magnetic storage medium, and information storage device
　本件は、磁気記憶媒体を製造する製造方法、磁気記憶媒体、および磁気記憶媒体を備えた情報記憶装置に関する。 This case relates to a manufacturing method for manufacturing a magnetic storage medium, a magnetic storage medium, and an information storage device including the magnetic storage medium.
　ハードディスクドライブ（ＨＤＤ）は、データの高速アクセス及び高速転送が可能な大容量記憶装置として、情報記憶装置の主流になっている。このＨＤＤについては、これまでも高い年率で面記録密度が高まっており、現在でもさらなる記録密度向上が求められている。 Hard disk drives (HDDs) have become the mainstream of information storage devices as mass storage devices capable of high-speed data access and high-speed transfer. As for this HDD, the surface recording density has been increasing at a high annual rate so far, and further improvement in recording density is still required.
　ＨＤＤの記録密度を向上させるためには、トラック幅の縮小や記録ビット長の短縮が必要であるが、トラック幅を縮小させると、隣接するトラック同士で、いわゆる干渉が生じ易くなる。この干渉とは、即ち、記録時において磁気記録情報が目的外の隣接トラックに重ね書きされてしまう現象や、再生時において目的外の隣接トラックからの漏洩磁界によるクロストークが起きてしまう現象を総称したものである。これらの現象は、いずれも再生信号のＳ／Ｎ比の低下を招き、エラーレートの劣化を引き起こす要因となる。 In order to improve the recording density of the HDD, it is necessary to reduce the track width and the recording bit length. However, if the track width is reduced, so-called interference tends to occur between adjacent tracks. This interference is a generic term for a phenomenon in which magnetic recording information is overwritten on a non-target adjacent track during recording, or a phenomenon in which crosstalk occurs due to a leakage magnetic field from a non-target adjacent track during reproduction. It is a thing. These phenomena all cause a decrease in the S / N ratio of the reproduction signal, and cause a deterioration in error rate.
　一方、記録ビット長の短縮を進めると、記録ビットを長期間保存する性能が低下する熱揺らぎ現象が発生する。 On the other hand, when the recording bit length is shortened, a thermal fluctuation phenomenon occurs in which the performance of storing the recording bits for a long period of time decreases.
　これらの干渉や熱揺らぎ現象を回避して短いビット長や高いトラック密度を実現する方法として、ディスクリート・トラック型の磁気記憶媒体やビットパターンド型の磁気記憶媒体が提案されている（例えば、特許文献１参照。）。特に、ビットパターンド型の磁気記憶媒体では、記録ビットの位置が予め決められており、その決められた記録ビットの位置に磁性材料のドットが形成されドットの相互間は非磁性材料で構成される。このように磁性材料のドットが互いに分離されているとドットどうしの磁気的相互作用が小さく、上述した干渉や熱揺らぎ現象が回避される。 Discrete track type magnetic storage media and bit patterned magnetic storage media have been proposed as a method for realizing a short bit length and high track density by avoiding these interference and thermal fluctuation phenomena (for example, patents). Reference 1). In particular, in bit-patterned magnetic storage media, the positions of recording bits are determined in advance, magnetic material dots are formed at the determined recording bit positions, and the dots are made of a non-magnetic material. The When the dots of the magnetic material are separated from each other in this way, the magnetic interaction between the dots is small, and the above-described interference and thermal fluctuation phenomenon are avoided.
　ここで、ビットパターンド型の磁気記憶媒体の製造方法として、上記特許文献１等に提案されている従来の製造方法について説明する。 Here, as a manufacturing method of the bit patterned magnetic storage medium, a conventional manufacturing method proposed in Patent Document 1 will be described.
　図１は、ビットパターンド型の磁気記憶媒体の従来の製造方法を示す図である。 FIG. 1 is a diagram showing a conventional manufacturing method of a bit patterned magnetic storage medium.
　従来の製造方法では、まず、製膜工程（Ａ）で、基板１上に磁性膜２が形成される。 In the conventional manufacturing method, first, the magnetic film 2 is formed on the substrate 1 in the film forming step (A).
　次に、ナノインプリント工程（Ｂ）では、磁性膜２上に、紫外線硬化樹脂からなるレジスト３が塗布され、そのレジスト３に、ナノサイズの穴４ａが空いたモールド４が載せられる。これによってレジスト３がそのナノサイズの穴４ａに入ってレジスト３のドット３ａが形成される。そして、そのモールド４越しにレジスト３に紫外線が照射されることでレジスト３が硬化してドット３ａが磁性膜２上にプリントされる。また、レジスト３が硬化した後、モールド４は除去される。 Next, in the nanoimprint process (B), a resist 3 made of an ultraviolet curable resin is applied on the magnetic film 2, and a mold 4 having nano-sized holes 4 a is placed on the resist 3. As a result, the resist 3 enters the nano-sized hole 4a, and the dots 3a of the resist 3 are formed. Then, the resist 3 is irradiated with ultraviolet rays through the mold 4, so that the resist 3 is cured and the dots 3 a are printed on the magnetic film 2. Further, after the resist 3 is cured, the mold 4 is removed.
　その後、エッチング工程（Ｃ）でエッチングが行われることで、レジスト３のドット３ａで保護された磁性ドット２ａを残して磁性膜が除去される。エッチング後はレジスト３のドット３ａは化学的処理で除去され、基板１上に磁性ドット２ａのみが残る。 Thereafter, etching is performed in the etching step (C), so that the magnetic film is removed leaving the magnetic dots 2 a protected by the dots 3 a of the resist 3. After etching, the dots 3 a of the resist 3 are removed by chemical treatment, and only the magnetic dots 2 a remain on the substrate 1.
　そして、充填工程（Ｄ）では、磁性ドット２ａの相互間が非磁性材料で埋められる。その後、平坦化工程（Ｅ）を経て表面が平坦化されることでビットパターンド型の磁気記憶媒体６の完成（Ｆ）となる。 In the filling step (D), the space between the magnetic dots 2a is filled with a nonmagnetic material. Thereafter, the surface is flattened through a flattening step (E), whereby the bit patterned magnetic storage medium 6 is completed (F).
　このような従来の製造方法によると、磁気記憶媒体６上での磁気ヘッドの浮上特性を安定なものとするために平坦化工程（Ｅ）では精度の高い平坦化が必要となる。そのため、非常に複雑な製造プロセスを行う必要があるという課題や、製造コストが増大するという課題が生じる。 According to such a conventional manufacturing method, high-precision flattening is required in the flattening step (E) in order to stabilize the flying characteristics of the magnetic head on the magnetic storage medium 6. Therefore, the subject that it is necessary to perform a very complicated manufacturing process and the subject that manufacturing cost increases arise.
　ここで、イオンが磁性膜に注入されると、その磁性膜の磁気特性が変化するということが知られている（例えば、特許文献２参照。）。そして、イオンを磁性膜に注入して局所的に磁気特性を変化させることでドットの分離状態を形成する加工方法（イオンドーピング方式）が提案されている（例えば、特許文献３および特許文献４参照。）。 Here, it is known that when ions are implanted into a magnetic film, the magnetic properties of the magnetic film change (see, for example, Patent Document 2). Then, a processing method (ion doping method) is proposed in which ions are implanted into the magnetic film to locally change the magnetic characteristics to form a dot separation state (see, for example, Patent Document 3 and Patent Document 4). .)
　このイオンドーピング方式によれば、イオンを注入して磁気特性を変えるため、エッチングや充填、平坦化等の複雑な製造プロセスが必要なくなり、製造コストの増加を大幅に抑えることが可能となる。 According to this ion doping method, ions are implanted to change the magnetic characteristics, so that complicated manufacturing processes such as etching, filling, and flattening are not required, and an increase in manufacturing cost can be significantly suppressed.
特許第１８８８３６３号明細書Japanese Patent No. 1888363 特開平０７－１４１６４１号公報Japanese Patent Laid-Open No. 07-141642 特開２００２－２８８８１３号公報JP 2002-288813 A 特開２００７－２２６８６２号公報JP 2007-226862 A
　しかしながら、単純にイオンドーピング方式を適用するだけでは、飽和磁化がほとんど変化しないため、上述した干渉や熱揺らぎ現象が解決できておらず、実用化には至っていない。 However, by simply applying the ion doping method, the saturation magnetization hardly changes, so the above-described interference and thermal fluctuation phenomenon cannot be solved, and it has not been put into practical use.
　尚、ここまで、ビットパターンド型の磁気記憶媒体を例に挙げて、上述のような簡易な製造方法が実用化に至っていないという課題について説明した。しかしながら、このような課題は、ビットパターンド型の磁気記憶媒体に限るものではなく、例えばディスクリート・トラック型の磁気記憶媒体にも当てはまる課題である。即ち、このような課題は、情報が磁気的に記録される磁性部と、磁性部の飽和磁化よりも小さい飽和磁化を有する低磁性部とを備えたタイプの磁気記憶媒体に共通して当てはまる課題である。 In addition, the problem that the simple manufacturing method as described above has not been put into practical use has been described so far by taking a bit patterned magnetic storage medium as an example. However, such a problem is not limited to the bit-patterned magnetic storage medium, and is also a problem that applies to, for example, a discrete track magnetic storage medium. That is, such a problem is commonly applied to a magnetic storage medium of a type including a magnetic part in which information is magnetically recorded and a low magnetic part having a saturation magnetization smaller than the saturation magnetization of the magnetic part. It is.
　本願では上記事情に鑑み、上記タイプの磁気記憶媒体を製造可能な簡易な製造方法、そのような簡易な製造方法で製造可能な上記タイプの磁気記憶媒体および情報記憶装置を提供することを目的とする。 In view of the above circumstances, an object of the present application is to provide a simple manufacturing method capable of manufacturing a magnetic storage medium of the above type, and a magnetic storage medium and an information storage device of the above type that can be manufactured by such a simple manufacturing method. To do.
　上記目的を達成する基本形態の磁気記憶媒体製造方法は、
　Ｓｍ－Ｃｏ基合金で磁性膜を形成する磁性膜形成過程と、
　上記磁性膜に対し、所定の保護領域を除いた他の領域に対して局所的にイオンを注入するイオン注入過程とを有することを特徴とする。 A magnetic storage medium manufacturing method of a basic form for achieving the above object is
A magnetic film forming process of forming a magnetic film with an Sm—Co based alloy;
The magnetic film includes an ion implantation process in which ions are locally implanted into other regions excluding a predetermined protective region.
　上記目的を達成する基本形態の磁気記憶媒体は、
　基板と、
　上記基板上に設けられた、Ｓｍ－Ｃｏ合金で形成された磁性膜を有し情報が磁気的に記録される磁性部と、
　上記磁性部の磁性膜と連続した磁性膜にイオンが注入されてなる被注入膜を有しその磁性部の飽和磁化よりも小さい飽和磁化を有する低磁性部とを備えたことを特徴とする。 A magnetic storage medium of a basic form that achieves the above object is
A substrate,
A magnetic part provided on the substrate and having a magnetic film formed of an Sm—Co alloy and on which information is magnetically recorded;
And a low magnetic part having a film to be implanted in which ions are implanted into a magnetic film continuous with the magnetic film of the magnetic part and having a saturation magnetization smaller than the saturation magnetization of the magnetic part.
　上記目的を達成する基本形態の情報記憶装置は、
　基板、その基板上に設けられた、その基板上にＳｍ－Ｃｏ合金で形成された磁性膜を有し情報が磁気的に記録される磁性部、および、その磁性部の磁性膜と連続した磁性膜にイオンが注入されてなる被注入膜を有しその磁性部の飽和磁化よりも小さい飽和磁化を有する低磁性部とを備えた磁気記憶媒体と、
　上記磁気記憶媒体に近接あるいは接触して磁性部に磁気的に情報の記録及び／又は再生を行う磁気ヘッドと、
　上記磁気ヘッドを上記磁気記憶媒体表面に対して相対的に移動させて、その磁気ヘッドによる情報の記録及び／又は再生となる磁性部上にその磁気ヘッドを位置決めするヘッド位置制御機構とを備えたことを特徴とする。 An information storage device of a basic form that achieves the above object,
A substrate, a magnetic part provided on the substrate and having a magnetic film formed of an Sm—Co alloy on the substrate, on which information is magnetically recorded, and a magnetic part continuous with the magnetic film of the magnetic part A magnetic storage medium comprising a film to be implanted in which ions are implanted into the film and a low magnetic part having a saturation magnetization smaller than the saturation magnetization of the magnetic part;
A magnetic head that magnetically records and / or reproduces information on a magnetic part in proximity to or in contact with the magnetic storage medium;
A head position control mechanism that moves the magnetic head relative to the surface of the magnetic storage medium and positions the magnetic head on a magnetic portion that records and / or reproduces information by the magnetic head. It is characterized by that.
　上記の基本形態の磁気記憶媒体製造方法によれば、例えばビットパターンド型の磁気記憶媒体の磁性ドット間を占める低磁性部や、ディスクリート・トラック型の磁気記憶媒体のトラックの両サイドを占める低磁性部を、イオン注入によって形成することができる。そのため、エッチングや充填や平坦化等といった複雑な製造プロセスが不要となるので、この基本形態の磁気記憶媒体製造方法は簡易な製造方法となる。また、上記の基本形態の磁気記憶媒体および情報記憶装置によれば、その簡易な製造方法での製造が可能となる。ここで、上記の各基本形態によれば、イオン注入を受ける磁性膜が、Ｓｍ－Ｃｏ基合金で形成される。このＳｍ－Ｃｏ基合金の磁性膜によれば、磁性ドットでの磁気記録に必要な磁気異方性を担保しつつ、イオン注入によって、十分な飽和磁化の低減が可能であることを本件の開発者は見出した。つまり、上記の各基本形態によれば、磁性膜の飽和磁化を局所的に低減させる上述の簡易な製造方法で、ビットパターンド型やディスクリート・トラック型の磁気記憶媒体や情報記憶装置を現実的に製造することができる。 According to the magnetic storage medium manufacturing method of the above basic form, for example, a low magnetic portion that occupies between magnetic dots of a bit patterned magnetic storage medium, or a low occupancy of both sides of a track of a discrete track magnetic storage medium The magnetic part can be formed by ion implantation. This eliminates the need for complicated manufacturing processes such as etching, filling, and planarization, so that the magnetic storage medium manufacturing method of this basic form is a simple manufacturing method. Further, according to the magnetic storage medium and the information storage device of the above basic form, it is possible to manufacture with the simple manufacturing method. Here, according to each of the basic forms described above, the magnetic film that receives the ion implantation is formed of an Sm—Co based alloy. According to this Sm—Co based alloy magnetic film, the saturation magnetization can be sufficiently reduced by ion implantation while ensuring the magnetic anisotropy necessary for magnetic recording with magnetic dots. Found. That is, according to each of the above basic modes, a bit patterned type or discrete track type magnetic storage medium or information storage device is realized by the above-described simple manufacturing method that locally reduces the saturation magnetization of the magnetic film. Can be manufactured.
　以上、説明したように、本件によれば、上記タイプの磁気記憶媒体を製造可能な簡易な製造方法、そのような簡易な製造方法で製造可能な上記タイプの磁気記憶媒体および情報記憶装置を得ることができる。 As described above, according to the present case, a simple manufacturing method capable of manufacturing the above type of magnetic storage medium, and the above type of magnetic storage medium and information storage device that can be manufactured by such a simple manufacturing method are obtained. be able to.
ビットパターンド型の磁気記憶媒体の従来の製造方法を示す図である。It is a figure which shows the conventional manufacturing method of a bit patterned type magnetic storage medium. 情報記憶装置の具体的な一実施形態であるハードディスク装置（ＨＤＤ）の内部構造を示す図である。It is a figure which shows the internal structure of the hard disk drive (HDD) which is one specific embodiment of an information storage device. 図２に示す磁気ディスクの構造を模式的に示す斜視図である。FIG. 3 is a perspective view schematically showing the structure of the magnetic disk shown in FIG. 2. 図２および図３に示す磁気ディスクの製造方法を示す図である。It is a figure which shows the manufacturing method of the magnetic disc shown in FIG. 2 and FIG. 第１実施例、第２実施例、および比較例に共通の構造を示す図である。It is a figure which shows a structure common to 1st Example, 2nd Example, and a comparative example. Ｓｍ－Ｃｏ合金の磁性膜およびＣｏ－Ｃｒ－Ｐｔ合金の磁性膜それぞれにおける磁気異方性磁界の膜厚依存性を示すグラフである。5 is a graph showing the film thickness dependence of the magnetic anisotropy field in each of a magnetic film of Sm—Co alloy and a magnetic film of Co—Cr—Pt alloy. 第１実施例についての、イオン注入による飽和磁化低減効果のイオン注入量依存性を示すグラフである。It is a graph which shows the ion implantation amount dependence of the saturation magnetization reduction effect by ion implantation about 1st Example. 第２実施例についての、イオン注入による飽和磁化低減効果のイオン注入量依存性を示すグラフである。It is a graph which shows the ion implantation amount dependence of the saturation magnetization reduction effect by ion implantation about 2nd Example.
　基本形態について上記説明した磁気記憶媒体製造方法、磁気記憶媒体、および情報記憶装置に対する具体的な実施形態を、以下図面を参照して説明する。 Specific embodiments of the magnetic storage medium manufacturing method, the magnetic storage medium, and the information storage device described above for the basic form will be described below with reference to the drawings.
　図２は、情報記憶装置の具体的な一実施形態であるハードディスク装置（ＨＤＤ）の内部構造を示す図である。 FIG. 2 is a diagram showing an internal structure of a hard disk device (HDD) which is a specific embodiment of the information storage device.
　この図に示すハードディスク装置（ＨＤＤ）１００は、パーソナルコンピュータ等といった上位装置に組み込まれ、その上位装置における情報記憶手段として利用されるものである。 The hard disk device (HDD) 100 shown in this figure is incorporated in a host device such as a personal computer and used as information storage means in the host device.
　このハードディスク装置１００には、円盤状の磁気ディスク１０が、図の奥行き方向に重なって複数枚ハウジングＨ内に納められている。この磁気ディスク１０は、上記で基本形態について説明した磁気記憶媒体の具体的な一実施形態に相当する。 In this hard disk device 100, a disk-shaped magnetic disk 10 is housed in a plurality of housings H so as to overlap in the depth direction of the figure. The magnetic disk 10 corresponds to a specific embodiment of the magnetic storage medium whose basic form has been described above.
　ここで、上述の磁気記憶媒体および情報記憶装置の基本形態に対し、
　「上記磁性部が、上記基板上に規則的に複数配列された、各々に情報が磁気的に記録される磁性ドットであり、
　上記低磁性部が、上記磁性ドットの相互間に設けられた、その磁性ドット相互の磁気的結合を阻害するドット間分断帯である」という応用形態は好適である。 Here, with respect to the basic form of the magnetic storage medium and the information storage device described above,
“The magnetic part is a plurality of magnetic dots regularly arranged on the substrate, and information is magnetically recorded on each,
An application mode in which the low magnetic part is an interdot separation band provided between the magnetic dots and hindering magnetic coupling between the magnetic dots is preferable.
　この応用形態は、ビット情報が記録される磁性ドットが予め基板上の各箇所に設けられているビットパターンド型の磁気記憶媒体に相当する。ビットパターンド型の磁気記憶媒体は、上述したように干渉や熱揺らぎ現象が効果的に回避されることから、そのようなタイプの磁気記憶媒体に相当する上記の応用形態は好適である。 This application form corresponds to a bit patterned magnetic storage medium in which magnetic dots on which bit information is recorded are provided in advance on each substrate. Since the bit-patterned magnetic storage medium effectively avoids interference and thermal fluctuation phenomena as described above, the above-described applied form corresponding to such a type of magnetic storage medium is preferable.
　図２の磁気ディスク１０は、ビットパターンド型の磁気記憶媒体であり、この応用形態の具体的な一実施形態にも相当している。また、この磁気ディスク１０は、各磁性ドットにおいて、表裏面に対して垂直な方向の磁化による磁気パターンで情報が記録されるいわゆる垂直磁気記憶媒体でもある。また、表裏面に対して長手方向の磁化による磁気パターンで情報が記録されるいわゆる面内磁気記憶媒体にも適用可能である。 The magnetic disk 10 in FIG. 2 is a bit-patterned magnetic storage medium and corresponds to a specific embodiment of this application form. The magnetic disk 10 is also a so-called perpendicular magnetic storage medium in which information is recorded in each magnetic dot with a magnetic pattern formed by magnetization in a direction perpendicular to the front and back surfaces. The present invention is also applicable to a so-called in-plane magnetic storage medium in which information is recorded with a magnetic pattern formed by longitudinal magnetization on the front and back surfaces.
　この磁気ディスク１０は、ハウジングＨ内においてディスク軸１１を中心に回転する。 The magnetic disk 10 rotates around the disk shaft 11 in the housing H.
　また、ハードディスク装置１００のハウジングＨ内には、磁気ディスク１０の表面に沿って移動するスイングアーム２０、スイングアーム２０の駆動に用いられるアクチュエータ３０、および制御回路５０も納められている。 In the housing H of the hard disk device 100, a swing arm 20 that moves along the surface of the magnetic disk 10, an actuator 30 that is used to drive the swing arm 20, and a control circuit 50 are also housed.
　スイングアーム２０は、磁気ディスク１０に対して情報の書き込みと読み出しとを行う磁気ヘッド２１を先端に保持している。また、スイングアーム２０は、ベアリング２４によってハウジングＨに回動自在に支持されている。そして、このスイングアーム２０は、ベアリング２４を中心として所定角度の範囲内で回動することによって、磁気ヘッド２１を磁気ディスク１０の表面に沿って移動させる。この磁気ヘッドが、上述した情報記憶装置の基本形態における磁気ヘッドの一例に相当する。 The swing arm 20 holds a magnetic head 21 for writing and reading information on the magnetic disk 10 at the tip. The swing arm 20 is rotatably supported by the housing H by a bearing 24. The swing arm 20 rotates within a range of a predetermined angle about the bearing 24 to move the magnetic head 21 along the surface of the magnetic disk 10. This magnetic head corresponds to an example of the magnetic head in the basic form of the information storage device described above.
　磁気ヘッド２１による情報の読み書きやアーム３０の移動は制御回路５０によって制御されており、上位装置との情報の遣り取りもこの制御回路５０を介して行われる。 The reading and writing of information by the magnetic head 21 and the movement of the arm 30 are controlled by the control circuit 50, and information exchange with the host device is also performed through this control circuit 50.
　上記のスイングアーム２０とベアリング２４とアクチュエータ３０と制御回路５０とを合わせたものが、上述した情報記憶装置の基本形態におけるヘッド位置制御機構の一例に相当する。 A combination of the swing arm 20, the bearing 24, the actuator 30, and the control circuit 50 corresponds to an example of a head position control mechanism in the basic form of the information storage device described above.
　図３は、図２に示す磁気ディスクの構造を模式的に示す斜視図である。 FIG. 3 is a perspective view schematically showing the structure of the magnetic disk shown in FIG.
　この図３には、円板状の磁気ディスクから切り出された一部が示されている。 FIG. 3 shows a part cut out from a disk-shaped magnetic disk.
　図３に示す磁気ディスク１０は、基板Ｓ上に複数の磁性ドットＱが規則的な配列で並べられた構造を有している。磁性ドットＱのそれぞれには１ビット相当の情報が磁気的に記録される。磁性ドットＱは磁気ディスク１０の中心の周りに周回状に並んでおり、磁性ドットの列はトラックＴを形成する。基板Ｓは、上述の基本形態における基板の一例に相当する。また、磁性ドットＱは、上述の基本形態における磁性部の一例に相当し、ビットパターンド型の磁気記憶媒体に対応した上述の応用形態における磁性ドットの一例にも相当している。 The magnetic disk 10 shown in FIG. 3 has a structure in which a plurality of magnetic dots Q are arranged on a substrate S in a regular arrangement. Information corresponding to 1 bit is magnetically recorded on each magnetic dot Q. The magnetic dots Q are arranged in a circle around the center of the magnetic disk 10, and the row of magnetic dots forms a track T. The board | substrate S is corresponded to an example of the board | substrate in the above-mentioned basic form. Further, the magnetic dot Q corresponds to an example of the magnetic portion in the basic form described above, and also corresponds to an example of the magnetic dot in the applied form described above corresponding to the bit patterned magnetic storage medium.
　また、磁性ドットＱの相互間は、飽和磁化が磁性ドットＱの飽和磁化よりも低く、磁性ドットＱの相互間を磁気的に分断するドット間分断帯Ｕとなっている。このドット間分断帯Ｕによって磁性ドットＱどうしの磁気的相互作用が小さくなっている。このドット間分断帯Ｕは、上述の基本形態における低磁性部の一例に相当し、ビットパターンド型の磁気記憶媒体に対応した上述の応用形態におけるドット間分断帯の一例にも相当している。 Further, between the magnetic dots Q, the saturation magnetization is lower than the saturation magnetization of the magnetic dots Q, and an interdot separation zone U that magnetically divides between the magnetic dots Q is formed. Due to the interdot dot U, the magnetic interaction between the magnetic dots Q is reduced. The interdot dot band U corresponds to an example of the low magnetic part in the basic mode described above, and also corresponds to an example of the interdot dot band in the application mode described above corresponding to the bit patterned magnetic storage medium. .
　このように磁性ドットＱどうしの磁気的相互作用が小さいと、磁性ドットＱに対する情報の記録再生に際してもトラックＴ相互間での磁気的相互作用が小さいため、トラック相互間でのいわゆる干渉が少ない。また、各磁性ドットＱでは、記録される情報ビットの境界が熱で揺らぐことがなく、いわゆる熱揺らぎ現象も回避される。従って、この図３に示すようなビットパターンド型の磁気ディスク１０によれば、トラック幅の縮小や記録ビット長の短縮が可能で、高記録密度の磁気記憶媒体が実現可能である。 Thus, when the magnetic interaction between the magnetic dots Q is small, the magnetic interaction between the tracks T is small even when information is recorded on and reproduced from the magnetic dots Q, so that there is little so-called interference between the tracks. Further, in each magnetic dot Q, the boundary of recorded information bits does not fluctuate due to heat, and so-called thermal fluctuation phenomenon is avoided. Therefore, according to the bit patterned magnetic disk 10 as shown in FIG. 3, the track width can be reduced and the recording bit length can be reduced, and a magnetic recording medium having a high recording density can be realized.
　この磁気ディスク１０の製造方法について以下説明する。 A method for manufacturing the magnetic disk 10 will be described below.
　この磁気ディスク１０の製造方法が、基本形態について上記説明した磁気記憶媒体製造方法の具体的な一実施形態に相当する。 The manufacturing method of the magnetic disk 10 corresponds to a specific embodiment of the magnetic storage medium manufacturing method described above with respect to the basic mode.
　ここで、この磁気記憶媒体製造方法の基本形態に対して、
　「上記イオン注入過程が、上記保護領域として、上記磁性膜が広がる方向に規則的に配列した複数箇所を用いて、その複数箇所の相互間に対して局所的にイオンを注入する過程である」という応用形態は好適である。 Here, for the basic form of this magnetic storage medium manufacturing method,
“The ion implantation process is a process in which ions are locally implanted between the plurality of locations using a plurality of locations regularly arranged in the direction in which the magnetic film spreads as the protective region.” The application form is suitable.
　この応用形態は、ビットパターンド型の磁気記憶媒体を製造する磁気記憶媒体製造方法に相当する。ビットパターンド型の磁気記憶媒体は、上述したように干渉や熱揺らぎ現象が効果的に回避されることから、そのようなタイプの磁気記憶媒体を製造する上記の応用形態は好適である。以下に説明する磁気ディスク１０の製造方法は、この応用形態の具体的な一実施形態にも相当している。 This application form corresponds to a magnetic storage medium manufacturing method for manufacturing a bit patterned magnetic storage medium. Since the bit-patterned magnetic storage medium effectively avoids interference and thermal fluctuation as described above, the above-described application form for manufacturing such a type of magnetic storage medium is preferable. The method of manufacturing the magnetic disk 10 described below corresponds to a specific embodiment of this application mode.
　図４は、図２および図３に示す磁気ディスクの製造方法を示す図である。 FIG. 4 is a diagram showing a method of manufacturing the magnetic disk shown in FIGS.
　この図４に示す製造方法では、まず、製膜工程（Ａ）で、ガラスの基板６１上に磁性膜６２が形成される。この製膜工程（Ａ）は、上述した磁気記憶媒体製造方法の基本形態における磁性膜形成過程の一例に相当し、この磁性膜６２は、Ｓｍ－Ｃｏ合金で形成された磁性膜である。 In the manufacturing method shown in FIG. 4, first, the magnetic film 62 is formed on the glass substrate 61 in the film forming step (A). This film forming step (A) corresponds to an example of a magnetic film forming process in the basic form of the magnetic storage medium manufacturing method described above, and this magnetic film 62 is a magnetic film formed of an Sm—Co alloy.
　ここで、本実施形態では、後述のイオン注入工程（Ｃ）でのイオン注入によって、磁性膜６２において図３のドット間分断帯Ｕに相当する領域の飽和磁化が低減される。磁性ドットＱの相互間を磁気的に確実に分断するドット間分断帯Ｕを形成するためには、飽和磁化は、イオン注入前のおよそ２０％まで低減されることが望ましい。一方で、磁性ドットＱでの磁気記録には、一般に、磁気異方性磁界で１４ｋＯｅ以上の磁気異方性が必要とされている。磁性ドットＱの磁気異方性は、磁性膜６２の磁気異方性であるので、磁性膜６２において上記の１４ｋＯｅ以上の磁気異方性が必要ということになる。ところが、従来、１４ｋＯｅ以上の磁気異方性を有する磁性膜の飽和磁化を、イオン注入によって注入前のおよそ２０％まで低減させることは非常に困難であった。 Here, in the present embodiment, saturation magnetization in a region corresponding to the interdot separation band U of FIG. 3 in the magnetic film 62 is reduced by ion implantation in an ion implantation step (C) described later. In order to form the interdot separation band U that magnetically and reliably divides the magnetic dots Q, it is desirable that the saturation magnetization is reduced to approximately 20% before ion implantation. On the other hand, magnetic recording with the magnetic dots Q generally requires a magnetic anisotropy of 14 kOe or more in a magnetic anisotropic magnetic field. Since the magnetic anisotropy of the magnetic dots Q is the magnetic anisotropy of the magnetic film 62, the magnetic anisotropy of 14 kOe or more is required in the magnetic film 62. However, conventionally, it has been very difficult to reduce the saturation magnetization of a magnetic film having a magnetic anisotropy of 14 kOe or more to about 20% before implantation by ion implantation.
　ここで、本件の開発者は、１×１０７ｅｒｇ／ｃｍ３以上という大きな磁気異方性定数を有するＳｍ－Ｃｏ合金によれば、５ｎｍ程度の膜厚で磁性膜を形成して、上記の１４ｋＯｅ以上の磁気異方性と飽和磁化の十分な低減とを両立できることを発見した。 Here, according to the Sm—Co alloy having a large magnetic anisotropy constant of 1 × 10 7 erg / cm 3 or more, the developer of this case forms a magnetic film with a film thickness of about 5 nm, It has been discovered that both a magnetic anisotropy of 14 kOe or more and a sufficient reduction in saturation magnetization can be achieved.
　図４の製膜工程（Ａ）では、磁性膜６２が、このような望ましい特性を有するＳｍ－Ｃｏ合金で、５ｎｍ程度の膜厚で形成される。 In the film forming step (A) of FIG. 4, the magnetic film 62 is formed of an Sm—Co alloy having such desirable characteristics with a thickness of about 5 nm.
　次に、ナノインプリント工程（Ｂ）では、磁性膜６２上に、紫外線硬化樹脂からなるレジスト６３が塗布され、そのレジスト６３に、ナノサイズの穴６４ａが空いたモールド６４が載せられる。これによってレジスト６３がそのナノサイズの穴６４ａに入ってレジスト６３のドット６３ａが形成される。そして、そのモールド６４越しにレジスト６３に紫外線が照射されることでレジスト６３が硬化してドット６３ａが磁性膜６２上にプリントされる。また、レジスト６３が硬化した後モールド６４は除去される。 Next, in the nanoimprint process (B), a resist 63 made of an ultraviolet curable resin is applied on the magnetic film 62, and a mold 64 with nano-sized holes 64 a is placed on the resist 63. As a result, the resist 63 enters the nano-sized hole 64a, and the dots 63a of the resist 63 are formed. Then, the resist 63 is irradiated with ultraviolet rays through the mold 64, so that the resist 63 is cured and the dots 63 a are printed on the magnetic film 62. Further, the mold 64 is removed after the resist 63 is cured.
　ナノインプリント工程（Ｂ）の後はイオン注入工程（Ｃ）に進む。このイオン注入工程（Ｃ）では、ドット６３ａがプリントされている磁性膜６２の上部から、酸素イオン、窒素イオンのうちのいずれか一方のイオンが照射される。その結果、レジスト６３のドット６３ａで保護された磁性ドット６２ａを残して磁性膜６２にイオンが注入されて飽和磁化が注入前の２０％まで低減される。このイオン注入工程（Ｃ）が、上述の基本形態におけるイオン注入過程の一例に相当する。また、このイオン注入工程（Ｃ）は、ビットパターンド型の磁気記憶媒体の製造に対応した上述の応用形態におけるイオン注入過程の一例にも相当している。 After the nanoimprint process (B), the process proceeds to the ion implantation process (C). In this ion implantation step (C), either one of oxygen ions and nitrogen ions is irradiated from above the magnetic film 62 on which the dots 63a are printed. As a result, ions are implanted into the magnetic film 62 leaving the magnetic dots 62a protected by the dots 63a of the resist 63, and the saturation magnetization is reduced to 20% before the implantation. This ion implantation step (C) corresponds to an example of the ion implantation step in the basic form described above. This ion implantation step (C) also corresponds to an example of an ion implantation process in the above-described applied mode corresponding to the manufacture of a bit patterned magnetic storage medium.
　ここで、上述の基本形態に対し、
　「上記イオン注入過程が、上記イオンとして、酸素イオン及び窒素イオンのうちいずれか一方のイオンを用いる過程である」という応用形態は好適である。 Here, in contrast to the basic form described above,
The application form that “the ion implantation process is a process using one of oxygen ions and nitrogen ions as the ions” is preferable.
　本件の開発者は、酸素イオンや窒素イオンによれば、Ｓｍ－Ｃｏ基合金で形成された磁性膜の磁気特性を効果的に劣化させることができることを発見した。この応用形態は、この発見に基づく形態であり好適であると言える。図４のイオン注入工程（Ｃ）は、この応用形態におけるイオン注入過程の一例にも相当している。 The developer of this case has discovered that oxygen ions and nitrogen ions can effectively degrade the magnetic properties of a magnetic film formed of an Sm—Co based alloy. This application form is based on this discovery and can be said to be suitable. The ion implantation process (C) in FIG. 4 corresponds to an example of an ion implantation process in this application mode.
　また、上述の基本形態に対し、
　「上記磁性膜上に、上記保護領域へのイオンの注入を阻害するマスクを形成するマスク形成過程を更に有し、
　上記イオン注入過程が、上記マスクが形成された磁性膜の上からイオンを当てることで、そのマスクで保護された保護領域を除いた他の領域に対して局所的にそのイオンを注入する過程である」という応用形態も好適である。 In contrast to the basic form described above,
“It further includes a mask forming process for forming a mask on the magnetic film that inhibits ion implantation into the protective region,
In the ion implantation process, ions are applied from above the magnetic film on which the mask is formed, so that the ions are locally implanted into other regions except for the protection region protected by the mask. An application form of “some” is also suitable.
　この応用形態によれば、イオン注入が不要な箇所はマスクで確実に保護されることとなり、磁性ドットの形成精度が高い。図４のナノインプリント工程（Ｂ）は、この応用形態におけるマスク形成過程の一例に相当し、イオン注入工程（Ｃ）は、この応用形態におけるイオン注入過程の一例にも相当する。 According to this applied form, the portions that do not require ion implantation are reliably protected by the mask, and the formation accuracy of the magnetic dots is high. The nanoimprint process (B) in FIG. 4 corresponds to an example of a mask formation process in this application form, and the ion implantation process (C) corresponds to an example of an ion implantation process in this application form.
　また、マスク形成過程を有したこの好適な応用形態に対し、
　「上記マスク形成過程が、上記マスクをレジストで形成する過程である」という応用形態や、
　「上記マスク形成過程が、上記マスクをレジストで、ナノインプリントプロセスによって形成する過程である」という応用形態はさらに好適である。 Also, for this preferred application with mask formation process,
"The mask forming process is a process of forming the mask with a resist",
An application form that “the mask forming process is a process of forming the mask with a resist by a nanoimprint process” is more preferable.
　レジストによるマスク形成は技術的に安定していて精度の良いマスク形成が期待でき、ナノインプリントプロセスによるマスク形成は、ナノレベルでのマスクパターンを容易に作成することが出来て好ましい。この図４に示すナノインプリント工程（Ｂ）は、これらさらに好適な応用形態におけるマスク形成過程の一例にも相当している。 Resist mask formation is technically stable and accurate mask formation can be expected, and nanoimprint process mask formation is preferable because it can easily create a nano-level mask pattern. The nanoimprint process (B) shown in FIG. 4 also corresponds to an example of a mask formation process in these more preferable applications.
　尚、上述したナノインプリントでは、イオンを注入するべき箇所でも完全にはレジストが除去されない。しかし、レジストが薄い場所ではイオンがレジストを透過して磁性膜６２に注入され、レジストが厚い場所（即ちドット６３ａとなっている場所）では、イオンがレジストで止まって磁性膜には到達しない。このため、所望のトラックパターンの形成が可能である。 In the nanoimprint described above, the resist is not completely removed even at the location where ions are to be implanted. However, when the resist is thin, ions pass through the resist and are injected into the magnetic film 62, and when the resist is thick (that is, where the dots 63a are formed), the ions stop at the resist and do not reach the magnetic film. Therefore, a desired track pattern can be formed.
　また、図４に示すイオン注入工程（Ｃ）では、イオンの加速電圧が、磁性膜６２の中心部へイオンが注入されるように設定される。この加速電圧は、イオン種によって異なり、磁性膜中心部までの深さや材料によっても異なる。 Further, in the ion implantation step (C) shown in FIG. 4, the acceleration voltage of ions is set so that ions are implanted into the central portion of the magnetic film 62. This acceleration voltage varies depending on the ion species, and also varies depending on the depth to the center of the magnetic film and the material.
　このイオン注入工程（Ｃ）によってイオンが注入された箇所の磁性膜６２は、内部にイオンが留まって結晶構造が歪み飽和磁化が低下する。イオン注入の後はレジストのドット６３ａは化学的処理で除去される。 In the magnetic film 62 where ions are implanted by this ion implantation step (C), ions remain inside, the crystal structure is distorted, and the saturation magnetization is lowered. After the ion implantation, the resist dots 63a are removed by chemical treatment.
　このようなイオン注入工程（Ｃ）を経ることにより、磁性ドット６２ａの相互間に、磁性ドット６２ａどうしの磁気的な相互作用を分断するドット間分断帯６２ｂが形成されてビットパターンド型の磁気記憶媒体１０の完成（Ｄ）となる。ドット間分断帯６２ｂでは飽和磁化が磁性ドット６２ａの飽和磁化よりも十分に低いため、情報は磁性ドット６２ａのみに記録され、ドット間分断帯６２ｂには情報は記録されない。 Through such an ion implantation step (C), an interdot separation band 62b for separating the magnetic interaction between the magnetic dots 62a is formed between the magnetic dots 62a, and a bit patterned magnetic field is formed. The storage medium 10 is completed (D). Since the saturation magnetization in the interdot separation band 62b is sufficiently lower than the saturation magnetization of the magnetic dot 62a, information is recorded only on the magnetic dot 62a, and no information is recorded in the interdot separation band 62b.
　この図４に示す製造方法で製造される磁気記憶媒体１０では、表面を構成している磁性ドット６２ａとドット間分断帯６２ｂとの平滑性は、製膜工程（Ａ）で形成された磁性膜６２における平滑性がそのまま維持されたものとなっている。このため、図１に示す従来技術のような平坦化工程は不要となり、この図４に示す製造方法は簡易な方法となっている。 In the magnetic storage medium 10 manufactured by the manufacturing method shown in FIG. 4, the smoothness of the magnetic dots 62a and the interdot separation bands 62b constituting the surface is the magnetic film formed in the film forming step (A). The smoothness at 62 is maintained as it is. Therefore, the planarization step as in the prior art shown in FIG. 1 is not necessary, and the manufacturing method shown in FIG. 4 is a simple method.
　また、この図４に示す製造方法では磁性膜６２上にプリントされたレジストのドット６３ａで磁性ドット６２ａを保護している。従って、磁気記憶媒体１０全面に同時にイオンを照射することができ、必要な箇所へのイオン注入を数秒間のイオン照射によって十分に実現できるので量産性を損なわない。 In the manufacturing method shown in FIG. 4, the magnetic dots 62 a are protected by the resist dots 63 a printed on the magnetic film 62. Accordingly, the entire surface of the magnetic storage medium 10 can be irradiated with ions at the same time, and ion implantation to a required portion can be sufficiently realized by ion irradiation for several seconds, so that mass productivity is not impaired.
　以下説明する第１および第２実施例では、この図４に示した製造方法を具体的な材料等に適用して技術的効果を確認した。また、この確認では、これらの実施例に対する比較例も適宜に参照されている。 In the first and second examples described below, the technical effects were confirmed by applying the manufacturing method shown in FIG. 4 to specific materials and the like. In this confirmation, comparative examples for these examples are also referred to as appropriate.
　図５は、第１実施例、第２実施例、および比較例に共通の構造を示す図である。 FIG. 5 is a diagram showing a structure common to the first example, the second example, and the comparative example.
　以下、この図５を参照しながら、まず、第１実施例について説明する。 Hereinafter, the first embodiment will be described first with reference to FIG.
　よく洗浄されたガラス基板７０をマグネトロンスパッタ装置にセットし、５×１０－５Ｐａ以下まで真空排気した。その後、ガラス基板７０を加熱せず０．６７ＰａのＡｒガス圧にて、（１１１）結晶配向したｆｃｃ－Ｃｕを、磁性層を結晶配向させるための下地層７１として５ｎｍの膜厚で成膜した。この下地層７１を成膜する過程は図４に示す製造方法では説明が省略されている。 A well-cleaned glass substrate 70 was set in a magnetron sputtering apparatus and evacuated to 5 × 10 −5 Pa or less. Thereafter, (111) crystal-oriented fcc-Cu was formed in a thickness of 5 nm as an underlayer 71 for crystal orientation of the magnetic layer without heating the glass substrate 70 at an Ar gas pressure of 0.67 Pa. . The process of forming the underlayer 71 is not described in the manufacturing method shown in FIG.
　続いて、大気圧に戻すことなく、装置内温度を２３０度に加熱し、Ｓｍ１７－Ｃｏ８３合金からなる磁性膜７２を０．６７ＰａのＡｒガス圧にて形成した。尚、「Ｓｍ１７－Ｃｏ８３合金」という表記における各下付きの数字は、各数字が添付されている元素の組成比を表わしている。 Subsequently, the temperature inside the apparatus was heated to 230 degrees without returning to atmospheric pressure, and a magnetic film 72 made of an Sm 17 —Co 83 alloy was formed at an Ar gas pressure of 0.67 Pa. Each subscript number in the notation “Sm 17 —Co 83 alloy” represents the composition ratio of the element to which each number is attached.
　尚、ここでは、３ｎｍ以上で１０ｎｍ未満の範囲内の膜厚で磁性膜７２を形成した。 Here, the magnetic film 72 was formed with a film thickness in the range of 3 nm or more and less than 10 nm.
　磁性膜７２を成膜した後には、ダイヤモンドライクカーボンを保護層７３として４ｎｍ成膜した。この保護層７３を成膜する過程も図４に示す製造方法では説明が省略されている。 After the magnetic film 72 was formed, 4 nm was formed as a protective layer 73 using diamond-like carbon. The process of forming the protective layer 73 is not described in the manufacturing method shown in FIG.
　さらに、磁性膜７２の形成後に、ＳＱＩＤ（Ｓｕｐｅｒｃｏｎｄｕｃｔｉｎｇ　Ｑｕａｎｔｕｍ　Ｉｎｔｅｒｆｅｒｅｎｃｅ　Ｄｅｖｉｃｅ）を用いて、上記の範囲内の各膜厚の磁性膜７２について、厚さ方向の磁気異方性磁界を測定した。この測定により、Ｓｍ－Ｃｏ合金の磁性膜７２について、磁気異方性磁界の膜厚依存性を得た。 Further, after the formation of the magnetic film 72, the magnetic anisotropy magnetic field in the thickness direction was measured for each film thickness 72 within the above range using SQID (Superducting Quantum Interference Device). By this measurement, the film thickness dependence of the magnetic anisotropic magnetic field was obtained for the magnetic film 72 of the Sm—Co alloy.
　次に、磁性膜７２の膜厚が５ｎｍのものについて、保護層７３上にはレジストを塗布し、ナノインプリントプロセスを用いて、直径が２０ｎｍ～６０ｎｍで、高さが約５０ｎｍの柱状のレジストパターン７４を形成した。 Next, when the magnetic film 72 has a thickness of 5 nm, a resist is applied on the protective layer 73, and a columnar resist pattern 74 having a diameter of 20 nm to 60 nm and a height of about 50 nm is applied using a nanoimprint process. Formed.
　レジストパターン７４の上方から５ｋｅＶに加速した窒素イオン７５を照射して磁性膜７２に注入した。上述したようにイオンの加速電圧は、磁性膜７２の中心部へイオンが注入されるように設定した。また、イオン注入は、０から２．５×１０１６ａｔｏｍｓ／ｃｍ２の範囲内でイオン注入量を徐々に増やしながら行なった。 Nitrogen ions 75 accelerated to 5 keV from above the resist pattern 74 were irradiated and implanted into the magnetic film 72. As described above, the acceleration voltage of ions was set so that ions were implanted into the central portion of the magnetic film 72. The ion implantation was performed while gradually increasing the ion implantation amount within the range of 0 to 2.5 × 10 16 atoms / cm 2 .
　また、ここでは、イオン注入前の磁性膜７２について飽和磁化を予め測定しておき、上記の範囲内の各イオン注入量でのイオン注入の度に、イオン注入を受けて低下した飽和磁化を測定し、前者に対する後者の比率を求めた。これにより、磁性膜７２について、窒素イオン７５の注入による飽和磁化低減効果のイオン注入量依存性を得た。 Here, the saturation magnetization of the magnetic film 72 before ion implantation is measured in advance, and the saturation magnetization lowered by receiving the ion implantation is measured every time the ion implantation is performed within the above range. The ratio of the latter to the former was obtained. As a result, the dependence of the saturation magnetization reduction effect due to the implantation of nitrogen ions 75 on the ion implantation amount was obtained for the magnetic film 72.
　イオン注入の後、レジストパターン７４をＳＣｌ洗浄によって除去した。 After the ion implantation, the resist pattern 74 was removed by SCl cleaning.
　次に、第２実施例として、膜厚が５ｎｍの磁性膜７２に、酸素イオンが注入されたものを作成した。尚、この第２実施例では、磁性膜７２の膜厚が５ｎｍのみであり、注入イオンのイオン種が酸素イオンである以外は、上記の第１実施例と同じ条件下で処理が行われた。また、この第２実施例については、酸素イオンの注入による飽和磁化低減効果のイオン注入量依存性に係る測定のみを行った。 Next, as a second example, a magnetic film 72 having a thickness of 5 nm was prepared by implanting oxygen ions. In the second embodiment, the process was performed under the same conditions as in the first embodiment except that the magnetic film 72 had a thickness of only 5 nm and the ion species of the implanted ions were oxygen ions. . In the second example, only the measurement related to the ion implantation amount dependency of the saturation magnetization reduction effect by oxygen ion implantation was performed.
　続いて、これら２つの実施例との比較のために、次のような比較例を作成した。この比較例では、磁性材料としてＣｏ－Ｃｒ３．３－Ｐｔ２２．５合金を用いる以外は、上記の第１実施例と同じ条件下で磁性膜の形成やイオン注入を行なった。尚、この比較例では、イオン注入による飽和磁化低減効果の、イオン注入量依存性に係る測定は省略し、Ｃｏ－Ｃｒ－Ｐｔ合金の磁性膜７２の磁気異方性磁界の膜厚依存性に係る測定のみを行った。 Then, the following comparative examples were created for comparison with these two examples. In this comparative example, a magnetic film was formed and ions were implanted under the same conditions as in the first example except that a Co—Cr 3.3 —Pt 22.5 alloy was used as the magnetic material. In this comparative example, the measurement related to the ion implantation amount dependency of the saturation magnetization reduction effect by the ion implantation is omitted, and the film thickness dependence of the magnetic anisotropic magnetic field of the magnetic film 72 of the Co—Cr—Pt alloy is omitted. Only such measurements were performed.
　図６は、Ｓｍ－Ｃｏ合金の磁性膜およびＣｏ－Ｃｒ－Ｐｔ合金の磁性膜それぞれにおける磁気異方性磁界の膜厚依存性を示すグラフである。 FIG. 6 is a graph showing the film thickness dependence of the magnetic anisotropy field in each of the Sm—Co alloy magnetic film and the Co—Cr—Pt alloy magnetic film.
　この図６のグラフＧ１では、横軸に磁性膜の膜厚がとられ、縦軸に磁気異方性磁界がとられている。そして、このグラフＧ１には、Ｓｍ－Ｃｏ合金の磁性膜７２における磁気異方性磁界の膜厚依存性が、丸印を結ぶ第１ラインＬ１で示されている。さらに、このグラフＧ１には、Ｃｏ－Ｃｒ－Ｐｔ合金の磁性膜７２における磁気異方性磁界の膜厚依存性が、四角印を結ぶ第２ラインＬ２で示されている。 In the graph G1 of FIG. 6, the horizontal axis represents the film thickness of the magnetic film, and the vertical axis represents the magnetic anisotropic magnetic field. In this graph G1, the film thickness dependence of the magnetic anisotropy field in the magnetic film 72 of the Sm—Co alloy is indicated by a first line L1 connecting circles. Further, in this graph G1, the film thickness dependence of the magnetic anisotropy field in the magnetic film 72 of the Co—Cr—Pt alloy is shown by the second line L2 connecting the square marks.
　第２ラインＬ２から、Ｃｏ－Ｃｒ－Ｐｔ合金の磁性膜では、磁気記録に必要とされている１４ｋＯｅ以上の磁気異方性磁界を得るためには、１０ｎｍ以上の膜厚が必要であることが分かる。これに対し、第１ラインＬ１から、Ｓｍ１７－Ｃｏ８３合金の磁性膜では、５ｎｍ以下の膜厚でも１４ｋＯｅ以上の磁気異方性磁界が得られることが分かる。 From the second line L2, the magnetic film of the Co—Cr—Pt alloy may require a film thickness of 10 nm or more in order to obtain a magnetic anisotropic magnetic field of 14 kOe or more required for magnetic recording. I understand. On the other hand, it can be seen from the first line L1 that a magnetic anisotropy magnetic field of 14 kOe or more can be obtained even with a film thickness of 5 nm or less in the magnetic film of Sm 17 —Co 83 alloy.
　次に、第１および第２実施例についての、イオン注入による飽和磁化低減効果のイオン注入量依存性を参照して、５ｎｍの膜厚での形成で１４ｋＯｅ以上の磁気異方性磁界が担保された磁性膜について飽和磁化を十分に低減できることを示す。尚、上述したように、ビットパターンド型の磁気記憶媒体において磁性ドットの相互間を磁気的に確実に分断するドット間分断帯を形成するためには、飽和磁化は、イオン注入前のおよそ２０％まで低減されることが望ましい。 Next, referring to the ion implantation amount dependency of the saturation magnetization reduction effect by the ion implantation in the first and second embodiments, a magnetic anisotropic magnetic field of 14 kOe or more is secured by forming with a film thickness of 5 nm. It is shown that the saturation magnetization of the magnetic film can be sufficiently reduced. Note that, as described above, in order to form an interdot separation band that magnetically and reliably divides between magnetic dots in a bit patterned magnetic storage medium, the saturation magnetization is about 20 before ion implantation. % Is desirable.
　図７は、第１実施例についての、イオン注入による飽和磁化低減効果のイオン注入量依存性を示すグラフであり、図８は、第２実施例についての、イオン注入による飽和磁化低減効果のイオン注入量依存性を示すグラフである。 FIG. 7 is a graph showing the dependency of the saturation magnetization reduction effect by ion implantation on the ion implantation amount for the first example, and FIG. 8 is the ion of the saturation magnetization reduction effect by ion implantation for the second example. It is a graph which shows injection amount dependence.
　図７のグラフＧ２および図８のグラフＧ３の双方とも、横軸にイオン注入量がとられ、縦軸に規格化飽和磁化がとられている。尚、縦軸の規格化飽和磁化は、イオン注入前の飽和磁化に対するイオン注入後の飽和磁化の比率で示されている。 In both the graph G2 in FIG. 7 and the graph G3 in FIG. 8, the horizontal axis represents the ion implantation amount, and the vertical axis represents the normalized saturation magnetization. The normalized saturation magnetization on the vertical axis is indicated by the ratio of the saturation magnetization after ion implantation to the saturation magnetization before ion implantation.
　図７のグラフＧ２では、窒素イオンの注入（第１実施例）による飽和磁化低減効果のイオン注入量依存性が、丸印を結ぶ第３ラインＬ３で示されている。また、図８のグラフＧ３では、酸素イオンの注入（第２実施例）による飽和磁化低減効果のイオン注入量依存性が、四角印を結ぶ第４ラインＬ４で示されている。 In the graph G2 of FIG. 7, the dependency of the saturation magnetization reduction effect by nitrogen ion implantation (first embodiment) on the ion implantation amount is shown by a third line L3 connecting circles. Further, in the graph G3 of FIG. 8, the dependency of the saturation magnetization reduction effect due to the implantation of oxygen ions (second embodiment) on the ion implantation amount is indicated by a fourth line L4 connecting square marks.
　これら２つのグラフＧ２，Ｇ３から、窒素イオンおよび酸素イオン双方とも、２×１０１６ａｔｏｍｓ／ｃｍ２のイオン注入量で、膜厚が５ｎｍの、Ｓｍ１７－Ｃｏ８３合金の磁性膜の飽和磁化を、注入前の２０％以下まで低減できることが分かる。一般に、イオン注入において、磁性膜の表面状態を損なわないためには、イオン注入量は、１×１０１７ａｔｏｍｓ／ｃｍ２以下であることが望ましいと言われている。これに対し、Ｓｍ１７－Ｃｏ８３合金の磁性膜に対する窒素イオンや酸素イオンの注入によれば、１×１０１７ａｔｏｍｓ／ｃｍ２という上限に対して十分な余裕を持って飽和磁化を低減できることが分かる。 From these two graphs G2 and G3, the saturation magnetization of the magnetic film of the Sm 17 —Co 83 alloy having a film thickness of 5 nm and an ion implantation amount of 2 × 10 16 atoms / cm 2 is obtained for both nitrogen ions and oxygen ions. It can be seen that it can be reduced to 20% or less before the injection. In general, in ion implantation, it is said that the ion implantation amount is desirably 1 × 10 17 atoms / cm 2 or less in order not to impair the surface state of the magnetic film. On the other hand, the saturation magnetization can be reduced with a sufficient margin with respect to the upper limit of 1 × 10 17 atoms / cm 2 by implanting nitrogen ions or oxygen ions into the magnetic film of the Sm 17 —Co 83 alloy. I understand.
　以上のことから、磁性膜をＳｍ－Ｃｏ合金で形成することにより、膜厚が５ｎｍでの形成で磁気記録に必要な１４ｋＯｅ以上の磁気異方性磁界を得つつ飽和磁化を十分に低減できることが確認された。従って、Ｓｍ－Ｃｏ合金を磁性材料に採用した上述の製造方法によれば、イオンドーピング方式を用いて、ビットパターンド型やディスクリート・トラック型の磁気記憶媒体や情報記憶装置を簡易かつ現実的に製造することができる。 From the above, by forming the magnetic film with an Sm—Co alloy, the saturation magnetization can be sufficiently reduced while obtaining a magnetic anisotropic magnetic field of 14 kOe or more necessary for magnetic recording when the film thickness is 5 nm. confirmed. Therefore, according to the above-described manufacturing method employing the Sm—Co alloy as a magnetic material, a bit patterned type or discrete track type magnetic storage medium or information storage device can be easily and practically used by using an ion doping method. Can be manufactured.
　尚、上述した説明では、磁気記憶媒体の一例として、ビットパターンド型の磁気記憶媒体を例示したが、磁気記憶媒体はに限るものではなく、例えばディスクリート・トラック型であっても良い。 In the above description, a bit patterned magnetic storage medium is illustrated as an example of the magnetic storage medium. However, the magnetic storage medium is not limited to this, and may be, for example, a discrete track type.
　また、上述した説明では、磁性膜を形成するＳｍ－Ｃｏ基合金の一例としてＳｍ－Ｃｏ合金を例示したが、Ｓｍ－Ｃｏ基合金はこれに限るものではない。このＳｍ－Ｃｏ基合金は、Ｓｍ－Ｃｏ合金の磁気特性等を損なわない組成範囲内で他の元素をＳｍ－Ｃｏ合金に添加した合金等であっても良い。 In the above description, the Sm—Co alloy is exemplified as an example of the Sm—Co based alloy forming the magnetic film, but the Sm—Co based alloy is not limited to this. The Sm—Co based alloy may be an alloy in which other elements are added to the Sm—Co alloy within a composition range that does not impair the magnetic properties of the Sm—Co alloy.
　また、上述した説明では、磁性ドット形成のための好ましいマスクとしてレジストパターンを用いることが例示されている。これに対し、上述した基本形態におけるイオン注入では、媒体のごく表面に、媒体面に接触しないようにステンシルマスクを配してイオン注入するプロセスを用いても良い。このプロセスによれば、レジスト塗布とレジスト除去の工程を省略することができる。 In the above description, the use of a resist pattern as a preferred mask for forming magnetic dots is exemplified. On the other hand, in the ion implantation in the basic form described above, a process in which a stencil mask is arranged on the very surface of the medium so as not to contact the medium surface may be used. According to this process, the steps of resist coating and resist removal can be omitted.
　また、上述した説明では、レジストのパターニングの最良な例としてナノインプリントプロセスを利用することが示されているが、パターニングには電子線露光を用いても良い。 In the above description, the nanoimprint process is shown to be used as the best example of resist patterning. However, electron beam exposure may be used for patterning.
　１００　　ハードディスク装置
　１０　　磁気ディスク
　６１　　基板
　６２　　磁性膜
　６２ａ　　磁性ドット
　６２ｂ　　分断帯 DESCRIPTION OF SYMBOLS 100 Hard disk device 10 Magnetic disk 61 Substrate 62 Magnetic film 62a Magnetic dot 62b Dividing band

Claims (10)

  1. 　Ｓｍ－Ｃｏ基合金で磁性膜を形成する磁性膜形成過程と、
    　前記磁性膜に対し、所定の保護領域を除いた他の領域に対して局所的にイオンを注入するイオン注入過程とを有することを特徴とする磁気記憶媒体製造方法。     A magnetic film forming process of forming a magnetic film with an Sm—Co based alloy;
    A method of manufacturing a magnetic storage medium, comprising: an ion implantation process in which ions are locally implanted into other regions excluding a predetermined protective region with respect to the magnetic film.
  2. 　前記イオン注入過程が、前記保護領域として、前記磁性膜が広がる方向に規則的に配列した複数箇所を用いて、該複数箇所の相互間に対して局所的にイオンを注入する過程であることを特徴とする請求項１記載の磁気記憶媒体製造方法。 The ion implantation process is a process of locally implanting ions between the plurality of locations using the plurality of locations regularly arranged in the direction in which the magnetic film spreads as the protection region. The method of manufacturing a magnetic storage medium according to claim 1.
  3. 　前記イオン注入過程が、前記イオンとして、酸素イオン及び窒素イオンのうちいずれか一方のイオンを用いる過程であることを特徴とする請求項１記載の磁気記憶媒体製造方法。 2. The method of manufacturing a magnetic storage medium according to claim 1, wherein the ion implantation process is a process using one of oxygen ions and nitrogen ions as the ions.
  4. 　前記磁性膜上に、前記保護領域へのイオンの注入を阻害するマスクを形成するマスク形成過程を更に有し、
    　前記イオン注入過程が、前記マスクが形成された磁性膜の上からイオンを当てることで、該マスクで保護された保護領域を除いた他の領域に対して局所的に該イオンを注入する過程であることを特徴とする請求項１から３のうちいずれか１項記載の磁気記憶媒体製造方法。     A mask forming step of forming a mask on the magnetic film that inhibits ion implantation into the protection region;
    The ion implantation process is a process in which ions are locally implanted into other regions other than the protection region protected by the mask by applying ions from above the magnetic film on which the mask is formed. The method of manufacturing a magnetic storage medium according to claim 1, wherein the magnetic storage medium is provided.
  5. 　前記マスク形成過程が、前記マスクをレジストで形成する過程であることを特徴とする請求項４記載の磁気記憶媒体製造方法。 The method of manufacturing a magnetic storage medium according to claim 4, wherein the mask forming process is a process of forming the mask with a resist.
  6. 　前記マスク形成過程が、前記マスクをレジストで、ナノインプリントプロセスによって形成する過程であることを特徴とする請求項４又は５記載の磁気記憶媒体製造方法。 6. The method of manufacturing a magnetic storage medium according to claim 4, wherein the mask forming process is a process of forming the mask with a resist by a nanoimprint process.
  7. 　基板と、
    　前記基板上に設けられた、Ｓｍ－Ｃｏ基合金で形成された磁性膜を有し情報が磁気的に記録される磁性部と、
    　前記磁性部の磁性膜と連続した磁性膜にイオンが注入されてなる被注入膜を有し該磁性部の飽和磁化よりも小さい飽和磁化を有する低磁性部とを備えたことを特徴とする磁気記憶媒体。     A substrate,
    A magnetic part provided on the substrate and having a magnetic film formed of an Sm—Co-based alloy and on which information is magnetically recorded;
    A magnetic material comprising: a film to be implanted in which ions are implanted into a magnetic film continuous with a magnetic film of the magnetic part; and a low magnetic part having a saturation magnetization smaller than a saturation magnetization of the magnetic part. Storage medium.
  8. 　前記磁性部が、前記基板上に規則的に複数配列された、各々に情報が磁気的に記録される磁性ドットであり、
    　前記低磁性部が、前記磁性ドットの相互間に設けられた、該磁性ドット相互の磁気的結合を阻害するドット間分断帯であることを特徴とする請求項７記載の磁気記憶媒体。     A plurality of the magnetic parts are regularly arranged on the substrate, each of which is a magnetic dot on which information is magnetically recorded,
    8. The magnetic storage medium according to claim 7, wherein the low magnetic part is an interdot separation band that is provided between the magnetic dots and inhibits magnetic coupling between the magnetic dots.
  9. 　基板、該基板上に設けられた、Ｓｍ－Ｃｏ基合金で形成された磁性膜を有し情報が磁気的に記録される磁性部、および、該磁性部の磁性膜と連続した磁性膜にイオンが注入されてなる被注入膜を有し該磁性部の飽和磁化よりも小さい飽和磁化を有する低磁性部とを備えた磁気記憶媒体と、
    　前記磁気記憶媒体に近接あるいは接触して磁性部に磁気的に情報の記録及び／又は再生を行う磁気ヘッドと、
    　前記磁気ヘッドを前記磁気記憶媒体表面に対して相対的に移動させて、該磁気ヘッドによる情報の記録及び／又は再生となる磁性部上に該磁気ヘッドを位置決めするヘッド位置制御機構とを備えたことを特徴とする情報記憶装置。     An ion is formed on a substrate, a magnetic portion having a magnetic film formed of an Sm—Co-based alloy, on which information is magnetically recorded, and a magnetic film continuous with the magnetic film of the magnetic portion. A magnetic storage medium comprising a film to be injected and a low magnetic part having a saturation magnetization smaller than the saturation magnetization of the magnetic part,
    A magnetic head that magnetically records and / or reproduces information on a magnetic part in proximity to or in contact with the magnetic storage medium;
    A head position control mechanism that moves the magnetic head relative to the surface of the magnetic storage medium and positions the magnetic head on a magnetic part that records and / or reproduces information by the magnetic head. An information storage device.
  10. 　前記磁気記憶媒体の磁性部が、前記基板上に規則的に複数配列された、各々に情報が磁気的に記録される磁性ドットであり、
    　前記低磁性部が、前記磁性ドットの相互間に設けられた、該磁性ドット相互の磁気的結合を阻害するドット間分断帯であることを特徴とする請求項９記載の情報記憶装置。     A plurality of magnetic portions of the magnetic storage medium are regularly arranged on the substrate, each of which is a magnetic dot on which information is magnetically recorded,
    The information storage device according to claim 9, wherein the low magnetic part is an interdot separation band that is provided between the magnetic dots and inhibits magnetic coupling between the magnetic dots.
PCT/JP2009/069560 2008-11-19 2009-11-18 Method for manufacturing magnetic storage medium, magnetic storage medium, and information storage device WO2010058792A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2008-295484 2008-11-19
JP2008295484A JP2010123179A (en) 2008-11-19 2008-11-19 Manufacturing method of magnetic storage medium, magnetic storage medium, and information storage device

Publications (1)

Publication Number Publication Date
WO2010058792A1 true WO2010058792A1 (en) 2010-05-27

Family

ID=42198231

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2009/069560 WO2010058792A1 (en) 2008-11-19 2009-11-18 Method for manufacturing magnetic storage medium, magnetic storage medium, and information storage device

Country Status (2)

Country Link
JP (1) JP2010123179A (en)
WO (1) WO2010058792A1 (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2010238332A (en) * 2009-03-31 2010-10-21 Hoya Corp Magnetic recording medium
CN103065646B (en) * 2011-10-24 2014-12-10 江苏海纳纳米技术开发有限公司 FePt nanometer cluster magnetic recording media

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001167420A (en) * 1999-09-27 2001-06-22 Tdk Corp Magnetic recording medium and its manufacturing method
JP2002288813A (en) * 2001-03-26 2002-10-04 Fuji Electric Co Ltd Magnetic recording medium and its manufacturing method
JP2008084433A (en) * 2006-09-27 2008-04-10 Hoya Corp Manufacturing method of magnetic recording medium
JP2009199674A (en) * 2008-02-22 2009-09-03 Fujitsu Ltd Magnetic recording medium and manufacturing method of same

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH05205257A (en) * 1992-01-28 1993-08-13 Toshiba Corp Magnetic recording medium

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001167420A (en) * 1999-09-27 2001-06-22 Tdk Corp Magnetic recording medium and its manufacturing method
JP2002288813A (en) * 2001-03-26 2002-10-04 Fuji Electric Co Ltd Magnetic recording medium and its manufacturing method
JP2008084433A (en) * 2006-09-27 2008-04-10 Hoya Corp Manufacturing method of magnetic recording medium
JP2009199674A (en) * 2008-02-22 2009-09-03 Fujitsu Ltd Magnetic recording medium and manufacturing method of same

Also Published As

Publication number Publication date
JP2010123179A (en) 2010-06-03

Similar Documents

Publication Publication Date Title
JP2008052860A (en) Manufacturing method of magnetic recording medium and magnetic recording and reproducing device
JP2008077756A (en) Magnetic recording medium and its manufacturing method, and magnetic recording and reproducing device
JP5422912B2 (en) Magnetic recording medium, method for manufacturing the same, and magnetic recording / reproducing apparatus
WO2010058793A1 (en) Method for manufacturing magnetic storage medium, magnetic storage medium, and information storage device
US8303828B2 (en) Method for manufacturing magnetic recording medium and magnetic recording-reproducing apparatus
JP5415745B2 (en) Magnetic storage medium manufacturing method, magnetic storage medium, and information storage device
JP5394729B2 (en) Magnetic storage medium manufacturing method, magnetic storage medium, and information storage device
WO2010058792A1 (en) Method for manufacturing magnetic storage medium, magnetic storage medium, and information storage device
KR101570893B1 (en) Method of manufacturing magnetic recording medium, magnetic recording medium, and information storage device
JP2009238273A (en) Manufacturing method of magnetic recording medium, magnetic recording medium and magnetic recording and reproducing device
JP2010134975A (en) Method of manufacturing magnetic storage medium, magnetic storage medium, and information storage device
JP4557994B2 (en) Method for manufacturing magnetic recording medium
JP5398228B2 (en) Membrane manufacturing method
JP5394688B2 (en) Magnetic storage medium manufacturing method, magnetic storage medium, and information storage device
JP5329212B2 (en) Magnetic storage medium manufacturing method
US8883265B2 (en) Method of manufacturing magnetic recording medium and magnetic recording/reproducing device
JP5345562B2 (en) Method for manufacturing magnetic recording medium
JP2010165398A (en) Magnetic recording medium and magnetic recording and reproducing device
JP2010097634A (en) Magnetic recording medium and information storage device
JP2010146603A (en) Magnetic recording medium, magnetic recording and reproducing device, and signal processing method of magnetic recording and reproducing device

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 09827573

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 09827573

Country of ref document: EP

Kind code of ref document: A1