JP2005158095A - Manufacturing method of master information carrier - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method for forming a master information carrier having no unevenness on the surface thereof capable of surely recording a digital information signal such as a pre-format recording. <P>SOLUTION: This carrier consists of a non-magnetic substrate on which a magnetism is imparted to a part corresponding to the digital signal on one main surface of the substrate 11 composed of a non-magnetic material, and the above part with the magnetism imparted thereto consists of a composition in which at least one element selected among Fe, Co, Ni is added to a structural element of the non-magnetic substrate, and after a thin film layer is arranged on the surface of the non-magnetic substrate, the above structural element is implanted to the surface of non-magnetic substrate through the thin film layer by an ion implanting means. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing a master information carrier used for recording a digital information signal on a magnetic recording medium.

  At present, the magnetic recording / reproducing apparatus tends to have a high recording density in order to realize a compact and large-capacity apparatus. In the field of hard disk drives, which are typical magnetic recording / reproducing devices, devices whose surface recording density exceeds 30 Gbit / in 2 (46.5 Mbit / mm 2) have already been commercialized. It is recognized that the technology has been advanced so rapidly that the practical application of a device of 100 Gbit / in 2 (155 Mbit / mm 2) is expected.

  For such high recording density, the tracking servo technology of the recording / reproducing head plays an important role. In the current tracking servo technology of magnetic recording media, magnetic recording media are provided with areas where tracking servo signals, address information signals, reproduction clock signals, etc. are recorded at regular angular intervals (hereinafter referred to as preformat recording). The head reproduces these signals at regular intervals to accurately scan the track while confirming and correcting the position of the magnetic head. (For example, Yamaguchi: High precision servo technology for magnetic disk drives, Japan application Journal of Magnetic Society, Vol.20, No.3, pp771, 1996).

  Since the tracking servo signal, the address information signal, the reproduction clock signal, and the like serve as reference signals for the magnetic head to accurately scan the track, accurate positioning accuracy is required at the time of recording. For this reason, conventionally, a magnetic recording medium is set in a dedicated servo recording device, and preformat recording is performed by a magnetic head whose position is strictly controlled (for example, Uematsu, et al .: current state of mechanical servo, HDI technology) And Prospect, Japan Society of Applied Magnetics, 93rd meeting material, 93-5, pp. 35, 1996).

  However, the conventional method for performing preformat recording using a dedicated servo recording apparatus has the following problems.

  First, since recording with a magnetic head is basically linear recording based on relative movement between the magnetic head and the magnetic recording medium, the conventional method requires a lot of time for preformat recording and is expensive. A dedicated servo recording device is required, and preformat recording is expensive.

  Second, due to the spread of the recording magnetic field due to the head-medium spacing and the pole shape of the recording head, there is a problem that the magnetization transition at the track end portion where preformat recording has been applied is steep. When the magnetization transition lacks steepness, it is difficult to realize an accurate tracking servo technique.

As a means to solve the problems of the conventional preformat recording using a magnetic head, a method using a master information carrier in which a ferromagnetic thin film pattern corresponding to an information signal of preformat recording is formed on the surface of a substrate is proposed. (Japanese Patent Laid-Open No. 10-40544). In this method, preformat recording is performed on a magnetic recording medium by magnetizing a ferromagnetic thin film formed on the master information carrier while the surface of the master information carrier is in contact with the surface of the magnetic recording medium. According to this method, good preformat recording can be performed efficiently without sacrificing other important performances such as the S / N ratio and interface performance of the recording medium.
JP 2002-74656 A Japanese Patent Laid-Open No. 10-40544

  As described above, when a digital information signal is recorded on a magnetic recording medium using a master information carrier, the master information carrier needs to be in close contact with the magnetic recording medium (for example, Japanese Patent Application Laid-Open No. 10-40544). At this time, if a gap of a certain degree or more is formed between the master information carrier and the magnetic recording medium, the recording ability from the master information carrier is lowered, and a sufficient signal cannot be written on the magnetic recording medium. Therefore, in particular, it is necessary to realize a good adhesion state between the ferromagnetic region of the master information carrier and the magnetic recording medium.

  When an ion implantation method is used as a method for forming a ferromagnetic pattern, it is necessary to uniformly and sufficiently implant a magnetic element up to the substrate surface. If the magnetic element is not injected up to the substrate surface, a gap is formed between the master information carrier and the magnetic recording medium, and the recording ability from the master information carrier is reduced, which is sufficient for the magnetic recording medium. The signal cannot be written. Therefore, it is preferable that the magnetic element is injected to the surface of the nonmagnetic substrate.

  In view of the above, an object of the present invention is to provide a method for manufacturing a master information carrier capable of reliably recording a digital information signal such as preformat recording on a magnetic recording medium with high quality.

  In order to achieve the above object, a master information carrier manufacturing method according to a first configuration of the present invention is a master information carrier for recording a digital signal on the magnetic recording medium by contacting the magnetic recording medium, A surface corresponding to the digital signal is formed on a surface of one main surface of a nonmagnetic substrate, and the portion provided with magnetism is at least one element selected from Fe, Co, and Ni as constituent elements of the nonmagnetic substrate. The composition is constituted by adding an element, and after the thin film layer is provided on the surface of the nonmagnetic substrate, the constituent element is implanted into the surface of the nonmagnetic substrate through the thin film layer by ion implantation means.

  In the master information carrier of the first configuration of the present invention, magnetism is imparted to one main surface of the nonmagnetic substrate, the surface of the master information carrier is not uneven, and a sufficient amount of magnetic elements are present even on the surface of the nonmagnetic substrate. It has a configuration that exists. For this reason, when the magnetic recording medium and the master information carrier are brought into contact with each other, it is possible to prevent a gap from being generated in the magnetic recording medium and the magnetic region of the master information carrier. Therefore, according to the master information carrier of the present invention, a good contact state can be obtained between the master information carrier and the magnetic recording medium, and a high quality and reliable digital signal can be reliably recorded on the magnetic recording medium. A possible master information carrier is obtained.

  An example of a specific manufacturing method of the master information carrier having the first configuration according to the present invention includes a first step of providing a thin film layer on one main surface on a non-magnetic substrate and a digital signal on the thin film layer. After a second step of forming a pattern to be formed with a resist, at least one element selected from Fe, Co, and Ni is implanted into one main surface of the nonmagnetic substrate through the thin film layer.

  In addition, after the first step of providing a thin film layer on one main surface on the nonmagnetic substrate, the thin film layer is interposed through a mask having an opening in a portion that becomes a magnetic region on one main surface on the nonmagnetic substrate. The element may be implanted into one main surface of the nonmagnetic substrate.

  By using the present invention, it is possible to easily manufacture a master information carrier in which the surface of the master information carrier has no irregularities and the magnetic element is sufficiently present even on the surface of the nonmagnetic substrate.

  According to a second aspect of the present invention, there is provided a master information carrier manufacturing method comprising: a master information carrier for recording a digital signal on the magnetic recording medium by contacting the magnetic recording medium; A ferromagnetic region corresponding to the digital signal and a non-magnetic region separating the ferromagnetic region, and the non-magnetic region is provided with a ferromagnetic thin film and a thin film layer on one main surface of the non-magnetic substrate. A part of the ferromagnetic thin film is demagnetized by implanting an element by ion implantation means through the thin film layer.

  In the method for producing a master information carrier according to the second aspect of the present invention, a digital information comprising a base made of a non-magnetic material and a thin film provided on the entire surface of the base, the thin film recording on a magnetic recording medium. A continuous film composed of a ferromagnetic region corresponding to a signal and a non-magnetic region that separates the ferromagnetic pattern. In the master information carrier according to the present invention, Since the magnetic region coexists, the surface of the master information carrier is not uneven. Thereby, when the magnetic recording medium and the master information carrier are brought into contact with each other, it is possible to prevent a gap from being generated in the magnetic recording medium and the continuous film. Therefore, according to the master information carrier produced by the manufacturing method of the above invention, a good contact state can be obtained between the master information carrier and the magnetic recording medium, and a high quality and reliable digital signal can be obtained on the magnetic recording medium. A master information carrier that can be reliably recorded is obtained.

  The means for demagnetizing a partial region of the ferromagnetic thin film is performed by implanting ions into the portion of the ferromagnetic thin film corresponding to the nonmagnetic region. By injecting nonmagnetic ions into the ferromagnetic material, the crystal structure of the ferromagnetic material can be changed, or it can be made nonmagnetic by alloying with nonmagnetic ions.

  An example of the method for producing the master information carrier of the second configuration of the present invention includes a first step of forming a ferromagnetic thin film on the entire main surface of a nonmagnetic substrate, and a thin film layer on the ferromagnetic thin film. And a third step of forming a pattern corresponding to a digital signal with a resist on the thin film layer, and then passing through the thin film layer to the ferromagnetic thin film on the nonmagnetic substrate through O, N, An ion selected from C is implanted.

  In addition, after going through the first step of forming a ferromagnetic thin film on the entire main surface of the nonmagnetic substrate and the second step of providing a thin film layer on the ferromagnetic thin film, An ion selected from O, N, and C may be implanted into the ferromagnetic thin film on the nonmagnetic substrate through the thin film layer through a mask having an opening.

  According to these methods, it is possible to form a structure in which ferromagnetic regions are separated and independent in a structurally continuous ferromagnetic thin film, and a master information carrier having no surface irregularities can be easily manufactured.

  As described above, according to the master information carrier of the present invention, a master information carrier capable of reliably recording a digital information signal on a magnetic recording medium can be obtained.

  Further, according to the method for producing a master information carrier of the present invention, the master information carrier of the present invention can be easily produced.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  First, an outline of the master information carrier will be described.

  A plan view of the master information carrier is schematically shown in FIG. It is an example of the master information carrier which records a signal on a hard disk. On one main surface of the master information carrier 10, a signal area 10a is formed. For example, as shown in FIG. 1, the signal region 10a is formed in a substantially radial shape.

  An enlarged view of a portion A surrounded by a dotted line in FIG. 1 is schematically shown in FIG. It is an example in the case of recording a servo signal. As shown in FIG. 2, a ferromagnetic region as a master information pattern is formed in the signal region 10a at a position corresponding to a digital information signal recorded on a magnetic recording medium. In FIG. 2, the hatched part is a part constituted by a ferromagnetic region.

  FIG. 2 shows a master information pattern for 10 tracks in the radial direction of the master information carrier 10 (that is, in the track width direction). For reference, after the master information pattern is transferred and recorded on the magnetic recording medium, a track portion that becomes a data area on the magnetic recording medium is indicated by a broken line.

  One main surface of the master information carrier 10 corresponds to a digital information signal recorded on the magnetic recording medium at every predetermined angle in the circumferential direction of the master information carrier 10 and for all recording tracks in the radial direction. A master information pattern 2 is formed.

  When the master information pattern is a servo pattern, for example, as shown in FIG. 2, each area of a clock signal, tracking servo signal, address information signal, etc. is sequentially arranged in the track length direction. FIG. 1 and FIG. 2 are examples, and the configuration and arrangement of the master information pattern change according to the digital information signal recorded on the magnetic recording medium.

  In the present embodiment, an example of a method for manufacturing a master information carrier according to the present invention will be described.

(Embodiment 1)
An example of a partial cross-sectional view in the bit length direction (track length direction) of the first configuration of the master information carrier 10 is schematically shown in FIG. The master information carrier 10 includes a nonmagnetic substrate 11 made of a nonmagnetic material, and a ferromagnetic region 12 a on one main surface of the nonmagnetic substrate 11.

  As the nonmagnetic substrate 11, for example, a glass substrate, a plastic substrate, a Si substrate, or the like can be used.

  The material constituting the ferromagnetic region 12a may be any material made of a ferromagnetic material and capable of transferring and recording a signal on a magnetic recording medium. For example, Fe, Co, Fe—Co alloy, or the like can be used. As described above, the ferromagnetic region 12a is formed at a position corresponding to a digital information signal (for example, preformat recording) recorded on the magnetic recording medium.

  As shown in FIG. 3, the master information carrier 10 has a structure in which magnetic ions are implanted into a ferromagnetic region 12a corresponding to a digital signal in a non-magnetic substrate 11.

(Example 1)
An example of a method for manufacturing the master information carrier 10 having the first configuration will be described with reference to FIG.

  As shown in FIG. 4A, as a first step, a thin film layer 16 is formed on a nonmagnetic substrate 11 made of 100 mm diameter silicon (Si). In Example 1, a resist was used for the thin film layer 16. Next, as shown in FIG. 4B, a pattern corresponding to a digital signal is formed on the thin film layer 16 using the resist film 13. For example, a photoresist can be used for the resist film 13. The resist film 13 is formed so as to have an opening 13a at a position corresponding to the digital signal pattern shown in FIG. When a photoresist is used for the resist film 13, as a method for forming a pattern corresponding to a digital signal, for example, a pattern can be formed using a mask aligner exposure machine. At this time, it is necessary to use different types of resist for the thin film layer 16 and the resist film 13 for forming a pattern corresponding to a digital signal. For example, when an i-line resist is used for the resist film 13, an electron beam drawing resist (for example, PMMA resist) that does not react with i-line is used as the resist for forming the thin film layer 16.

  Next, as shown in FIG. 4 (c), the entire surface of the resist film 13 and the nonmagnetic substrate 11 exposed through the opening 13a of the resist film 13 is irradiated with an ion beam, thereby implanting iron (Fe) ions. Went. In order to uniformly distribute Fe ions in the thickness direction of the nonmagnetic substrate 11, ion implantation was performed in three stages. FIG. 5 shows the ion implantation conditions when the thickness of the thin film layer 16 is 70 nm, and FIG. 6 shows the Fe ion concentration distribution in the film thickness direction in the region where ion implantation is performed by SIMS (secondary ion mass spectrometry). As a result of analysis, it was almost uniform in the depth direction.

  Note that the conditions shown in FIG. 6 are conditions for uniformly implanting the ion concentration up to an implantation depth of 100 nm. In the case of implanting deeper, the condition for increasing the implantation energy may be added.

  For comparison, FIG. 7 shows the implantation conditions when Fe ions are implanted by a conventional method in which the thin film layer 16 is not formed, and FIG. 8 shows the ion concentration distribution in the depth direction at that time. As a result of the analysis, a decrease in ion concentration near the surface was observed.

  It was found that by using the manufacturing method of the present invention, ions can be implanted into the nonmagnetic substrate 11 easily and uniformly.

  Thereafter, as shown in FIG. 4D, the master information carrier 10 in which magnetism is imparted to the surface of the nonmagnetic substrate 11 can be manufactured by removing the resist film 13 using a chemical solution such as a remover. In addition, by using a resist for the thin film layer 16, the thin film layer 16 can be removed at the same time as the resist film 13 is removed.

  When the surface shape of one main surface of the nonmagnetic substrate 11 on which Fe ions were implanted was observed with an AFM (atomic force microscope), no change in the surface shape due to the influence of ion implantation was observed.

  Next, after applying and removing a magnetic field in parallel to the non-magnetic substrate 11, the magnetization state of the surface of the non-magnetic substrate 11 was observed with an MFM (magnetic force microscope), and according to the ion-implanted region. A pattern of non-magnetic and magnetic regions was observed. Further, when the magnetization of the region where ion implantation was performed was measured by VSM, it was ferromagnetic.

  As described above, as shown in FIG. 3, it was confirmed that the master information carrier 10 having a structure in which the ferromagnetic region 12 provided with magnetism by the magnetic element ion implantation exists on the surface of the nonmagnetic substrate 11 was obtained.

  As described above, according to the master information carrier manufacturing method of the first embodiment, the master information carrier having the first configuration described in the first embodiment can be easily manufactured.

  In the present embodiment, the case where Si is implanted into the nonmagnetic substrate 11 and Fe ions are implanted as the implanted ion magnetic element is described, but this is not restrictive. In order to use the magnetic region 12 as an alloy, for example, in the case of an iron-nickel (Fe—Ni) alloy, Ni ions may be implanted after Fe ions are implanted.

(Example 2)
Another example of the method for manufacturing the master information carrier 10 having the first configuration will be described with reference to FIG.

  As shown in FIG. 9A, as a first step, a thin film layer 16 is formed on a nonmagnetic substrate 11 made of 100 mm diameter silicon (Si). In Example 2, a resist film was used for the thin film layer 16.

  Next, as shown in FIG. 9B, the non-magnetic substrate 11 was irradiated with the Fe ion beam 14 through a mask 15 produced by processing a 0.5 mm thick silicon substrate. The mask 15 has an opening 15 a at a location corresponding to a region where ion implantation is performed on the nonmagnetic substrate 11. Ion implantation conditions such as the thickness of the thin film layer 16 are the same as those in the first embodiment.

  The Fe ion concentration distribution in the film thickness direction of the region where ion implantation was performed by SIMS (secondary ion mass spectrometry) was analyzed. It was almost uniform in the depth direction from the analysis result.

  Note that the conditions shown in FIG. 7 are conditions for uniformly implanting ions up to an implantation depth of 100 nm. In the case of implanting even deeper, a condition where the implantation energy is increased may be added.

  It was found that by using the manufacturing method of the present invention, ions can be implanted into the nonmagnetic substrate 11 easily and uniformly.

  Thereafter, as shown in FIG. 9C, the master information carrier 10 in which magnetism is imparted to the surface of the nonmagnetic substrate 11 can be manufactured by removing the thin film layer 16 using a chemical solution such as a remover. In addition, by using a resist for the thin film layer 16, it can be more easily manufactured.

  When the surface shape of one main surface of the nonmagnetic substrate 11 on which Fe ions were implanted was observed with an AFM (atomic force microscope), no change in the surface shape due to the influence of ion implantation was observed.

  Next, after applying and removing a magnetic field in parallel to the non-magnetic substrate 11, the magnetization state of the surface of the non-magnetic substrate 11 was observed with an MFM (magnetic force microscope), and according to the ion-implanted region. A pattern of non-magnetic and magnetic regions was observed. Further, when the magnetization of the region where ion implantation was performed was measured by VSM, it was ferromagnetic.

  As described above, as shown in FIG. 3, it was confirmed that the master information carrier 10 having a structure in which the ferromagnetic region 12 provided with magnetism by the magnetic element ion implantation exists on the surface of the nonmagnetic substrate 11 was obtained.

  In the present embodiment, the case where Si is implanted into the nonmagnetic substrate 11 and Fe ions are implanted as the implanted ion magnetic element is described, but this is not restrictive. In order to use the magnetic region 12 as an alloy, for example, in the case of an iron-nickel (Fe—Ni) alloy, Ni ions may be implanted after Fe ions are implanted.

  Next, an example of a method of using the master information carrier 10 having the first configuration manufactured using the first and second embodiments will be described with reference to FIG.

  As shown in FIG. 10A, the magnetic information is transferred to the magnetic recording medium 20 by magnetizing the ferromagnetic region 12a of the master information carrier 10 in a state where the master information carrier 10 is in close contact with the magnetic recording medium 20. For example, preformat recording) can be recorded. In addition, after magnetizing the ferromagnetic region 12 a in advance, the digital information signal can be recorded on the magnetic recording medium 20 by bringing the master information carrier 10 into close contact with the magnetic recording medium 20.

  The magnetic recording medium 20 is, for example, a magnetic disk used for a hard disk or the like.

  FIG. 10B schematically shows a state when preformat recording is performed on a magnetic disk having the magnetic recording layer 20a. As shown in FIG. 10B, a magnetic signal is recorded on the magnetic recording layer 20a of the magnetic disk so as to correspond to the ferromagnetic region 12a.

  Thus, when recording a digital information signal on a magnetic recording medium using the master information carrier 10 of the present invention, it is necessary to bring the master information carrier 10 into close contact with the magnetic recording medium 20. Since the master information carrier 10 of the present invention has no irregularities on the surface, when the master information carrier 10 and the magnetic recording medium 20 are brought into close contact with each other, there is no gap between the ferromagnetic region 12a and the magnetic recording layer 20a. Therefore, the digital information signal can be reliably recorded on the magnetic recording medium.

(Embodiment 2)
In Embodiment 2, an example of a partial cross-sectional view in the bit length direction (track length direction) of the second configuration of the master information carrier 10 is schematically shown in FIG. The master information carrier 10 includes a nonmagnetic substrate 11 made of a nonmagnetic material, and a ferromagnetic region 12 a on one main surface of the nonmagnetic substrate 11.

  As the nonmagnetic substrate 11, for example, a glass substrate, a plastic substrate, a Si substrate, or the like can be used.

  The material constituting the ferromagnetic region 12a may be any material made of a ferromagnetic material and capable of transferring and recording a signal on a magnetic recording medium. For example, Fe, Co, Fe—Co alloy, or the like can be used. As described above, the ferromagnetic region 12a is formed at a position corresponding to a digital information signal (for example, preformat recording) recorded on the magnetic recording medium.

  As shown in FIG. 11, the master information carrier 10 has a ferromagnetic region 12a on the nonmagnetic substrate 11 which is a ferromagnetic pattern corresponding to a digital information signal recorded on a magnetic recording medium, and a nonmagnetic material which separates the ferromagnetic pattern. The non-magnetic region 12b is formed by implanting ions of O, C, and N into the ferromagnetic thin film 12 and formed of a continuous film composed of the formation region 12b.

(Example 3)
In Example 3, an example of manufacturing the master information carrier 10 having the second configuration described in Embodiment 2 will be described with reference to FIG.

First, as shown in FIG. 12A, on a nonmagnetic substrate 11 made of 100 mm diameter silicon (Si), sputtering is performed under the conditions of ultimate vacuum of 2 × 10 ⁻⁷ Pa and Ar gas pressure of 0.13 Pa. A ferromagnetic thin film 12 was formed by forming an iron (Fe) film having a thickness of 100 nm.

  When the magnetization of the deposited ferromagnetic thin film 12 was measured with a VSM (vibrating sample magnetometer), the saturation magnetization was 1650 emu / cc.

  As shown in FIG. 12B, a thin film layer 16 is formed on the ferromagnetic thin film 12 formed on the nonmagnetic substrate 11. In Example 3, a resist was used for the thin film layer 16. Next, as shown in FIG. 12C, a pattern corresponding to a digital signal is formed on the thin film layer 16 using the resist film 13. For example, a photoresist can be used for the resist film 13. The resist film 13 has an opening 13 a on a region where ions are implanted into the ferromagnetic thin film 12.

  When a photoresist is used for the resist film 13, as a method for forming a pattern corresponding to a digital signal, for example, a pattern can be formed using a mask aligner exposure machine. At this time, it is necessary to use different types of resist for the thin film layer 16 and the resist film 13 for forming a pattern corresponding to a digital signal. For example, when an i-line resist is used for the resist film 13, an electron beam drawing resist (for example, PMMA resist) that does not react with i-line is used as the resist for forming the thin film layer 16.

  Next, as shown in FIG. 12D, the entire surface of the ferromagnetic thin film 12 exposed through the resist film 13 and the opening 13a of the resist film 13 is irradiated with an ion beam, thereby implanting nitrogen (N) ions. Went. In order to uniformly distribute N ions in the thickness direction of the ferromagnetic thin film 12, ion implantation was performed in three stages. FIG. 13 shows the ion implantation conditions when the thickness of the thin film layer 16 is 70 nm, and FIG. 14 shows the N ion concentration distribution in the film thickness direction in the region where ion implantation by SIMS (secondary ion mass spectrometry) is performed. As a result of analysis, it was almost uniform in the depth direction.

  Note that the conditions shown in FIG. 13 are conditions for uniformly implanting ions up to an implantation depth of 100 nm. In the case of implanting even deeper, a condition where the implantation energy is increased may be added.

  For comparison, FIG. 15 shows the implantation conditions when N ions are implanted by a conventional method in which the thin film layer 16 is not formed, and FIG. 16 shows the ion concentration distribution in the depth direction at that time. As a result of the analysis, a decrease in ion concentration near the surface was observed.

  It was found that by using the manufacturing method of the present invention, ions can be implanted into the nonmagnetic substrate 11 easily and uniformly.

  Thereafter, as shown in FIG. 12E, the resist film 13 is removed by using a chemical solution such as a remover, thereby having a structure in which a ferromagnetic region and a nonmagnetic region coexist in a structurally continuous film. A master information carrier 10 can be manufactured.

  In addition, by using a resist for the thin film layer 16, the thin film layer 16 can be removed at the same time as the resist film 13 is removed.

  When the surface shape of the ferromagnetic thin film 12 was observed with an AFM (atomic force microscope), no change in shape was observed in the region where ion implantation was performed, compared to the region where ion implantation was not performed.

  Next, after applying and removing a magnetic field in parallel to the nonmagnetic substrate 11, the magnetization state of the ferromagnetic thin film 12 was observed with an MFM (magnetic force microscope). As a result, the nonmagnetic property corresponding to the ion-implanted region was observed. A pattern of regions and magnetic regions was observed. Further, when the magnetization of the region into which ion implantation was performed was measured by VSM, it was non-magnetic.

  As described above, it was confirmed that the master information carrier 10 having a structure in which the ferromagnetic region 12a and the nonmagnetic region 12b coexist in a structurally continuous thin film was obtained as shown in FIG.

  As described above, according to the master information carrier manufacturing method of the third embodiment, the master information carrier 10 having the second configuration described in the second embodiment can be easily manufactured.

  In the present embodiment, the case where Fe is implanted into the ferromagnetic thin film 12 and N ions are implanted as the implanted ion magnetic element is described, but this is not restrictive.

Example 4
In Example 4, another example of manufacturing the master information carrier 10 having the second configuration described in Embodiment 2 will be described with reference to FIG.

First, as shown in FIG. 17A, on a non-magnetic substrate 11 made of silicon (Si) having a diameter of 100 mm, a sputtering method is performed under conditions of an ultimate vacuum of 2 × 10 ⁻⁷ Pa and an Ar gas pressure of 0.13 Pa. A ferromagnetic thin film 12 was formed by forming an iron (Fe) film having a thickness of 100 nm.

  When the magnetization of the deposited ferromagnetic thin film 12 was measured with a VSM (vibrating sample magnetometer), the saturation magnetization was 1650 emu / cc.

  Next, as shown in FIG. 17B, the ferromagnetic thin film 12 on which the thin film layer 16 was formed was irradiated with an ion beam 14 through a mask 15 manufactured by processing a 0.5 mm thick silicon substrate. The mask 15 has an opening 15 a at a location corresponding to a region where ion implantation is performed on the ferromagnetic thin film 12. The conditions for ion implantation are the same as in Example 3.

  As described above, as shown in FIG. 17C, the master information carrier 10 having the second configuration having the structure in which the ferromagnetic region 12a and the nonmagnetic region 12b coexist in a structurally continuous film. Produced.

  When the surface shape of the ferromagnetic thin film 12 was observed with an AFM (atomic force microscope), no change was observed in the region where ion implantation was performed compared to the region where ion implantation was not performed.

  Next, after applying and removing a magnetic field in parallel to the nonmagnetic substrate 11, the magnetization state of the ferromagnetic thin film 12 was observed with an MFM (magnetic force microscope), and the nonmagnetic property corresponding to the ion-implanted region was observed. A pattern of regions and magnetic regions was observed. Further, when the magnetization of the region into which ion implantation was performed was measured by VSM, it was non-magnetic.

  Further, when the N ion concentration distribution in the film thickness direction of the region where ion implantation was performed was analyzed, it was almost uniform in the depth direction as in Example 3.

  As described above, it was confirmed that the master information carrier 10 having a structure in which the ferromagnetic region 12a and the nonmagnetic region 12b coexist in a structurally continuous thin film was obtained as shown in FIG.

  As described above, according to the master information carrier manufacturing method described in the fourth embodiment, the master information carrier 10 having the second configuration described in the second embodiment can be easily manufactured.

  In this embodiment, the case where Fe is implanted into the ferromagnetic thin film 12 and N ions are implanted as the implanted ion magnetic element is described, but this is not restrictive.

  Next, an example of a method of using the master information carrier 10 having the above-described second configuration, which is manufactured using Example 3 and Example 4, will be described with reference to FIG.

  As shown in FIG. 10A, the magnetic information recording medium 20 is obtained by magnetizing the ferromagnetic region 12a of the master information carrier 10 in a state where the master information carrier 10 having the second configuration is in close contact with the magnetic recording medium 20. A digital information signal (for example, a preformat recording) can be recorded on. In addition, after magnetizing the ferromagnetic region 12 a in advance, the digital information signal can be recorded on the magnetic recording medium 20 by bringing the master information carrier 10 into close contact with the magnetic recording medium 20.

  The magnetic recording medium 20 is, for example, a magnetic disk used for a hard disk or the like.

  FIG. 10B schematically shows a state when preformat recording is performed on a magnetic disk having the magnetic recording layer 20a. As shown in FIG. 10B, a magnetic signal is recorded on the magnetic recording layer 20a of the magnetic disk so as to correspond to the ferromagnetic region 12a.

  Thus, when a digital information signal is recorded on a magnetic recording medium using the master information carrier 10 of the present invention, it is necessary to bring the master information carrier 10 into close contact with the magnetic recording medium 20. In the master information carrier 10 of the present invention, since there is no unevenness on the surface, when the master information carrier 10 and the magnetic recording medium 20 are brought into close contact, there is no gap between the ferromagnetic region 12a and the magnetic recording layer 20a. Therefore, the digital information signal can be reliably recorded on the magnetic recording medium.

  According to the above embodiment, the effect of the present invention was confirmed.

The thin film layer 16 desirably has a density of 2.5 g / cm ³ or less.

  Although the embodiments of the present invention have been described above by way of examples, the present invention is not limited to the above-described embodiments, and can be applied to other embodiments based on the technical idea of the present invention.

  For example, in the above embodiment, a master information carrier for transferring and recording a digital information signal on a magnetic recording medium mainly mounted on a hard disk drive or the like has been described. However, the master information carrier of the present invention is a flexible magnetic disk, magnetic It can also be applied to magnetic recording media such as cards and magnetic tapes.

  In the above embodiment, the case where the information signal recorded on the magnetic recording medium is a preformat signal composed of a tracking servo signal, an address information signal, a reproduction clock signal, etc. has been mainly described. The master information carrier of the present invention can also be used for recording. For example, it is possible in principle to record various data signals, audio and video signals using the master information carrier of the present invention. In this case, the master information carrier of the present invention and the recording technology on the magnetic recording medium using the master information carrier allow mass production of soft disk media, and the soft disk media can be provided at low cost. is there.

  By using the master information carrier manufacturing method according to the present invention, a master information carrier for transferring and recording a digital information signal on a magnetic recording medium mounted on a disk drive or the like can be manufactured with high quality and easily. Useful.

  Also, it can be applied in principle as an ion implantation process for semiconductors.

Schematic diagram showing an example of the master information carrier of the present invention The schematic diagram which shows an example of a master information pattern about the master information carrier of this invention Sectional drawing which shows an example about the 1st structure of the master information carrier of this invention Process diagram showing an example of a manufacturing method for the master information carrier of the first configuration of the present invention The figure which shows an example of ion implantation conditions about the manufacturing method of the master information carrier of the 1st structure of this invention. Composition analysis diagram in the depth direction by SIMS of a master information carrier produced using the method for producing a master information carrier of the first configuration of the present invention The figure which shows an example of the ion implantation conditions in the manufacturing method of the conventional master information carrier The figure which shows an example of the composition analysis result of the depth direction by SIMS of the master information carrier produced using the manufacturing method of the conventional master information carrier Process drawing which shows an example of the manufacturing method in the master information carrier of the 1st structure of this invention Process diagram showing an example of use in the master information carrier of the present invention Sectional drawing which shows an example of the 2nd structure of the master information carrier of this invention Process drawing which shows an example of the manufacturing method in the master information carrier of the 2nd structure of this invention The figure which shows an example of the ion implantation conditions in the manufacturing method of the master information carrier of the 2nd structure of this invention The figure which shows an example of the composition analysis result of the depth direction by SIMS of the master information carrier produced using the manufacturing method of the master information carrier of the 2nd structure of this invention The figure which shows an example of the ion implantation conditions in the manufacturing method of the conventional master information carrier The figure which shows an example of the composition analysis result of the depth direction by SIMS of the master information carrier produced using the manufacturing method of the conventional master information carrier Process drawing which shows another example of the manufacturing method in the master information carrier of the 2nd structure of this invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Master information carrier 10a Signal area 11 Nonmagnetic base 12 Ferromagnetic thin film 13 Resist film 14 Ion beam 15 Mask 16 Thin film layer 20 Magnetic recording medium 20a Magnetic recording film

Claims (8)

A master information carrier for recording a digital signal on the magnetic recording medium by being brought into contact with the magnetic recording medium, comprising a non-magnetic substrate having magnetism applied to a portion corresponding to the digital signal on one main surface. ,
The portion imparted with magnetism is composed of a composition in which at least one element selected from Fe, Co, and Ni is added to the constituent elements of the nonmagnetic substrate,
A method for producing a master information carrier, comprising: providing a thin film layer on the surface of the nonmagnetic substrate, and then implanting the constituent element into the surface of the nonmagnetic substrate through the thin film layer by ion implantation means. After a first step of providing a thin film layer on one main surface on the nonmagnetic substrate and a second step of forming a pattern corresponding to a digital signal on the thin film layer with a resist,
2. The method of manufacturing a master information carrier according to claim 1, wherein ions are implanted into one main surface of the nonmagnetic substrate through the thin film layer. After the first step of providing a thin film layer on one main surface on the nonmagnetic substrate, the thin film layer passes through the thin film layer through a mask having an opening in a portion that becomes a magnetic region on one main surface on the nonmagnetic substrate. 2. The method for producing a master information carrier according to claim 1, wherein ion implantation is performed on one main surface of the non-magnetic substrate. A master information carrier for recording a digital signal on the magnetic recording medium by contacting the magnetic recording medium,
The surface of the non-magnetic substrate is composed of a ferromagnetic region corresponding to the digital signal and a non-magnetic region that separates the ferromagnetic region.
The nonmagnetic region is formed by providing a ferromagnetic thin film layer and a thin film layer on one main surface of the nonmagnetic substrate, and then implanting elements into the ferromagnetic thin film through the thin film layer by ion implantation means. A method for producing a master information carrier. A first step of forming a ferromagnetic thin film on the entire main surface of the nonmagnetic substrate; a second step of providing a thin film layer on the ferromagnetic thin film; and a pattern corresponding to a digital signal on the thin film layer After passing through the third step of forming with resist
5. The method of manufacturing a master information carrier according to claim 4, wherein ions are implanted into the ferromagnetic thin film on the nonmagnetic substrate through the thin film layer. After the first step of forming a ferromagnetic thin film on the entire main surface of the non-magnetic substrate and the second step of providing a thin film layer on the ferromagnetic thin film,
5. The method of manufacturing a master information carrier according to claim 4, wherein ions are implanted into the ferromagnetic thin film on the nonmagnetic substrate through the thin film layer through a mask having an opening in a portion to become a nonmagnetic region. 7. The method of manufacturing a master information carrier according to claim 4, wherein the ions implanted into the ferromagnetic thin film are made of O, N, and C. 7. The method of manufacturing a master information carrier according to claim 1, wherein the thin film layer is made of a nonmagnetic material.

Images