JP2009271967A - Method for manufacturing magnetic recording medium, magnetic recording medium, and magnetic recording and reproducing device - Google Patents

Abstract

A mask layer is removed after patterning of a magnetic layer so that no residue is generated, the smoothness of the surface of a recording layer can be improved, and nanoimprinting of a resist layer can be performed with high accuracy.
In a method of manufacturing a magnetic recording medium for manufacturing a magnetic recording medium having at least a recording layer 4 on a nonmagnetic substrate, a step of forming the recording layer 4 on the nonmagnetic substrate 1, A step of forming a mask layer 5 containing Si, a step of oxidizing the surface of the mask layer 5, a step of forming a resist layer 7 on the oxidized surface of the mask layer 5, and patterning the resist layer 7 It has a step of forming a concavo-convex pattern on the mask layer 5, a step of magnetically separating the recording layer 4 using the concavo-convex pattern of the mask layer 5, and a step of removing the mask layer 5.
[Selection] Figure 1

Description

  The present invention relates to a method for manufacturing a magnetic recording medium, a magnetic recording medium, and a magnetic recording / reproducing apparatus for manufacturing a magnetic recording medium having at least a recording layer on a nonmagnetic substrate.

  In recent years, the application range of magnetic recording and reproducing devices such as magnetic disk devices, floppy (registered trademark) disk devices, and magnetic tape devices has been remarkably increased, and the importance has increased. The recording density is being significantly improved.

  In particular, since the introduction of MR heads (magnetoresistance effect type heads) and PRML (Partial Response Maximum Likelihood) technology, the increase in surface recording density has become more intense, and in recent years, GMR heads (giant magnetoresistive effect type heads), With the introduction of TMR heads (tunnel magnetoresistive heads), it continues to increase at a pace of about 100% per year.

  For these magnetic recording media, it is required to achieve a higher recording density in the future. For this purpose, a higher coercive force of the magnetic recording layer, a higher signal-to-noise ratio (S / N ratio), and higher resolution must be achieved. Is required. In recent years, the absolute film thickness of the medium has been reduced in order to achieve a high surface recording density, and as a result, the phenomenon that the recording magnetization is weakened by thermal disturbance is becoming a problem. Thermal stability has become a major technical issue. In particular, there are many cases where the thermal stability is lowered when trying to improve the above-described SN ratio, and the coexistence of these two is a development target. This is because, in general, in a medium having an excellent SN ratio, the crystal grain size of the magnetic particles constituting the magnetic layer is often fine, which is effective for medium noise, but the thermal stability of magnetism. This is because it can be said that it is close to the unstable region from the viewpoint.

  In recent years, efforts have been made to increase the surface recording density by increasing the track density at the same time as improving the linear recording density. In the latest magnetic recording and reproducing apparatus, the track density has reached 110 kTPI. However, as the track density is increased, magnetic recording information between adjacent tracks interfere with each other, and the problem that the magnetization transition region in the boundary region becomes a noise source and the S / N ratio is easily lost. This directly leads to a decrease in bit error rate, which is an obstacle to improvement in recording density.

  In addition, since the distance between tracks is getting closer, magnetic recording and playback devices are required to have extremely high precision track servo technology. At the same time, recording is performed widely, and playback is performed during recording to eliminate the influence of adjacent tracks as much as possible. A method of performing it more narrowly is generally used. Although this method can minimize the influence between tracks, it is difficult to obtain a sufficient reproduction output, and it is difficult to secure a sufficient S / N ratio. In recent years, a perpendicular magnetic recording medium has been used to ensure the thermal stability of the medium as described above.

  As described above, the perpendicular magnetic recording medium is used as a technique for increasing the recording density. However, in order to further increase the recording density even in the perpendicular magnetic recording, it is necessary to increase the track density. Also in the perpendicular magnetic recording medium, it is necessary to reduce writing fringes at the recording end, which is a problem, by increasing the track density.

As an example of a method for solving this fringe, a discrete track medium can be considered (for example, see Patent Documents 1 and 2 below).
JP-A-6-259709 JP-A-9-97419

  Patent Document 1 proposes a discrete medium structure in which a data portion is a convex portion and a separation region is a concave portion. However, it is not preferable to provide a concave separation region because it has a problem of affecting the flying characteristics of the recording / reproducing head because an uneven portion is present on the disk surface.

  Next, the above-mentioned Patent Document 2 proposes a discrete medium in which the separation region is embedded with an embedding material and the disk surface is flat. As a method for manufacturing a discrete medium, for example, a step of forming a continuous magnetic layer on a nonmagnetic substrate, a step of forming a patterned mask layer on the surface, and a magnetic layer is partially removed using the pattern. A step of filling a non-magnetic material into the step where the magnetic layer has been removed is used. In this process, a general photolithography technique is used for forming a patterned mask layer on the surface of the continuous magnetic layer.

As a nonmagnetic embedding agent for embedding the recesses between the magnetic layer patterns, for example, Patent Document 3 below discloses the use of SiO ₂ or C. Further, in this patent document 3, when manufacturing a discrete medium, there is a method of forming a ferromagnetic layer on a medium substrate, applying a resist, imprinting a stamper on the resist, and transferring the uneven pattern. It is disclosed. At this time, it is important to select a resist, but when SOG (Spin On Glass) is used as the resist, the shape transferability is good and the rectangularity of the produced pattern is excellent. For this reason, it is preferable to manufacture a discrete medium through an imprint process using SOG.
JP 2006-277868 A

  However, after the imprint process, if the magnetic layer is etched using the SOG to which the concavo-convex pattern has been transferred as a mask, the SOG remains as a mask residue on the top of the magnetic layer and remains as a protrusion on the surface of the recording layer, making it difficult to smooth the surface. For this reason, the glide evaluation was rejected, and the productivity of the magnetic recording medium was lowered.

  In addition, it is possible to use a substance that does not easily leave residue as a mask material. However, even when such a material is used, conventionally, nanoimprinting of the resist layer cannot be performed with high accuracy, and the productivity of the magnetic recording medium is reduced. It was one of the causes.

  The present invention has been made in view of the above circumstances, and it is possible to improve the smoothness of the surface of the recording layer without generating a residue by removing the mask layer after the patterning process of the magnetic layer, and to improve the nanoimprint of the resist layer. An object of the present invention is to provide a method of manufacturing a magnetic recording medium, a magnetic recording medium, and a magnetic recording / reproducing apparatus that can be performed with high accuracy and can manufacture a magnetic recording medium with high productivity.

  In order to achieve the above object, (1) the first invention provides a magnetic recording medium manufacturing method for manufacturing a magnetic recording medium having at least a magnetically separated recording layer on a nonmagnetic substrate. A step of forming a recording layer on the substrate; a step of forming a mask layer containing Si on the recording layer; a step of oxidizing the surface of the mask layer; and an oxidized surface of the mask layer A step of forming a resist layer, a step of patterning the resist layer to form an uneven pattern on the mask layer, a step of magnetically separating the recording layer using the uneven pattern of the mask layer, and the mask layer And a step of removing.

  (2) In a second invention, in the invention described in the above item (1), the mask layer containing Si is made of Si.

  (3) A third invention is the invention described in the above item (1) or (2), wherein the resist layer is patterned by an imprint method using a stamper.

  (4) A fourth invention is a magnetic recording medium manufactured by the manufacturing method described in any one of (1) to (3).

  (5) A fifth invention is a magnetic recording / reproducing apparatus comprising a magnetic recording medium and a magnetic head for recording / reproducing information on the magnetic recording medium, wherein the magnetic recording medium is described in the above item (4). It is a magnetic recording medium.

  According to the present invention, since the mask layer containing Si is formed on the recording layer and the surface of the mask layer is oxidized, the etching layer can be easily removed without leaving any residue on the surface of the recording layer. And the smoothness of the recording layer surface can be improved.

  In addition, since the surface of the mask layer is oxidized, it has good wettability with general resists, and no voids are generated at the interface, so the nanoimprint process of the resist layer provided on the surface of the mask layer can be performed with high accuracy. It can be carried out.

  Therefore, a magnetic recording medium having a fine magnetic recording pattern can be manufactured with high productivity.

  Embodiments of the present invention will be described in detail with reference to the drawings.

  1 and 2 show a method of manufacturing a magnetic recording medium according to the present invention. FIG. 1A shows a process of forming a recording layer and a silicon mask layer on a substrate and oxidizing the surface of the silicon mask layer. 1B is a cross-sectional view showing a state in which a resist is formed, FIG. 1C is a cross-sectional view showing a state imprinted by a stamper, and FIG. 1D is a view in which a recess is removed by etching. FIG. 2E is a cross-sectional view showing a state in which a patterned mask layer is formed, FIG. 2E is a cross-sectional view showing a state in which the mask layer is removed by etching, and the recording layer remains only on the convex portion, and FIG. FIG. 2G is a cross-sectional view showing a state in which the surface is smoothed, FIG. 2H is a cross-sectional view showing a state in which a protective film is formed, and FIG. It is sectional drawing which shows the state in which the lubricating layer was formed.

  In the magnetic recording medium of the present invention, a magnetic recording track portion or a bit portion is formed by a separation region provided around the magnetic recording track portion or bit portion. The magnetic recording medium of the present invention is manufactured by the following process shown in FIGS. 1 and 2, for example.

  1) A soft magnetic backing layer 2, an orientation control layer 3, a recording layer 4, and a mask layer 5 containing Si are sequentially formed on a disk-like nonmagnetic substrate 1 to form a laminated structure 6. 5 is oxidized (see FIG. 1A). In FIG. 1A, only a part of the surface-side magnetic recording region of the disk-shaped nonmagnetic substrate 1 is shown enlarged.

  2) A resist 7 is applied to the surface of the laminated structure 6 formed in the step 1) to obtain a medium 8. If necessary, baking is performed to remove excess organic solvent and the like (see FIG. 1B).

  3) A metal mold (stamper) 9 formed on the surface with a concavo-convex portion 9a designed according to a desired distance between tracks and between bits is adhered to the surface of the medium 8 obtained in the process described in 2) above. Then, by pressing at a high pressure, a track-shaped or bit-shaped uneven portion is formed on the surface of the medium 8 (hereinafter referred to as an imprint process) (see FIG. 1C). Note that the previous stamper 9 is actually a disk shape that matches the disk-shaped non-magnetic substrate 1, but FIG. 1C shows only a part of the uneven portion of the stamper 9.

  4) Using a technique such as dry etching or reactive ion etching, the resist 7 at the bottom of the concave groove 11b, the mask layer 5, and the recording among the concave and convex portions of the medium 8 obtained in the process described in 3) above. The layer 4 and, if necessary, the orientation control layer 3 and the soft magnetic backing layer 2 are partially removed. In FIG. 1D, the resist 7, the mask layer 5, and the recording layer 4 are removed (first etching process).

  5) The resist 7 and the mask layer 5 of the convex portion 11a are removed by using a peeling gas among the concave and convex portions of the medium 8 obtained in the process described in 3) above (second etching process) (FIG. 2 ( E)).

  As a result of this process, the concavo-convex portion 11 made of a part of the magnetic recording layer along the concavo-convex portion of the track formed in the process described in 3) above remains. The concavo-convex portion 11 obtained here has a structure in which convex portions 11a of track portions or bit portions to be magnetically recorded and concave grooves 11b located between these convex portions 11a are intermittently formed in the diameter direction. (See FIG. 2E).

  6) Above these structures, a nonmagnetic material is deposited using a technique such as sputtering to form a deposition layer 12, and the convex portions 11 a formed intermittently in the diameter direction of the nonmagnetic substrate 1. The non-magnetic material is filled into the concave grooves 11b formed between 11a (hereinafter referred to as a filling process). At this time, it is necessary to fill the nonmagnetic material to the depth of the concave groove 11b on the magnetic recording medium (see FIG. 2F).

  7) Thereafter, the unevenness remaining on the surface of the magnetic recording medium is smoothed by dry etching such as ion etching, for example, so that the surface of the magnetic recording medium is a smooth surface 13 (hereinafter referred to as a smoothing process). By this process, separation regions 14 made of a non-magnetic material are formed inside each concave groove 11b, and each recording track portion or bit portion 15 is formed so as to be partitioned by these separation regions 14 (FIG. 2G )reference).

  8) Finally, a DLC (Diamond Like Carbon) film to be the protective film 16 is formed again using a film forming method such as plasma CVD (see FIG. 2H). Further, a lubricating layer 17 is formed on the protective film 16 as necessary (see FIG. 2I). Through the above steps, the perpendicular magnetic recording medium A having the structure shown in FIG. 2I can be obtained.

  The perpendicular magnetic recording medium A obtained in this mode has a laminated structure in which a soft magnetic backing layer 2, an orientation control layer 3, a recording layer 4, and a protective film 16 are sequentially formed on the surface of a disk-like nonmagnetic substrate 1. The laminated structure is separated by a plurality of concave grooves 11b so as to form a concentric recording track portion or bit portion 15 having a predetermined width, and each concave groove 11b is filled with a nonmagnetic material and separated. A region 14 is formed, and a protective film 16 and a lubricating layer 17 are formed so as to cover the separation region 14 and the recording track portion 15.

  In the present invention, as described above, since the mask layer 5 is made of a material that hardly generates a residue in the second etching process, the surface of the recording layer 4 can be kept smooth without leaving a residue on the surface of the recording layer 4. It becomes. In addition, since the surface of the mask layer 5 is oxidized, the wettability with a general resist 7 is good, and voids or the like are not generated at the interface. Therefore, the nanoimprint process of the resist 7 provided on the surface of the mask layer 5 is enhanced. It becomes possible to carry out with accuracy.

  In the present invention, as the non-magnetic substrate 1, for example, an Al alloy substrate such as an Al-Mg alloy containing Al as a main component, a substrate made of crystallized glass, amorphous glass, silicon, titanium, ceramics, carbon, various resins, etc. Any nonmagnetic substrate can be used. A lithium-based crystallized substrate can be used as the crystallized glass substrate, and examples of the amorphous substrate include soda lime glass and aluminosilicate glass.

  When the average surface roughness Ra of the nonmagnetic substrate 1 is 1 nm or less, preferably 0.5 nm or less, the perpendicular orientation of the recording layer 4 to be formed in the subsequent process becomes good. Further, the pressure distribution in the imprint process Is preferable from the viewpoint of reducing the thickness and improving the processing uniformity.

  If the surface of the non-magnetic substrate 1 has a fine waviness Wa of 0.3 nm or less, the pressure distribution in the imprint process is reduced, which is preferable from the viewpoint of improving processing uniformity.

  The soft magnetic backing layer 2 is made of a soft magnetic material, and examples of the material include materials containing Fe, Co, and Ni. Examples of this material include FeCo alloys (FeCoB, FeCoSiB, FeCoZr, FeCoZrB, etc.), FeTa alloys (FeTaN, FeTaC, etc.), and Co alloys (CoTaZr, CoZrNb, CoB, etc.).

  The soft magnetic backing layer 2 is preferably a laminated structure. That is, by providing Ru, Re, and Cu between the soft magnetic films and setting them to a predetermined thickness, the soft magnetic films provided above and below can be antiferromagnetically coupled. By adopting such a configuration, it is possible to improve the phenomenon of WATE (Wide Area Track Erasure), which is a problem peculiar to the perpendicular magnetic recording medium.

  The orientation control layer 3 is for controlling the crystal orientation and crystal size of the recording layer 4 provided thereon. The material used for this film is preferably a material having an hcp structure or an fcc structure. Ru is particularly preferable.

  The thickness of the orientation control layer 3 is preferably 30 nm or less. If the thickness of the orientation control layer 3 exceeds 30 nm, the distance between the magnetic head and the soft magnetic backing layer 2 at the time of recording / reproducing increases, so that the OW characteristic (overwrite characteristic) and the resolution of the reproduced signal are lowered, which is not preferable. .

  The recording layer 4 has an easy axis of magnetization in a direction perpendicular to the substrate surface. As a magnetic alloy of this layer, a known one can be used, but in the present invention, it is particularly preferable to use a magnetic alloy having a granular structure.

  In particular, in the present invention, the recording layer is preferably composed of a magnetic material having a granular structure containing at least Co, Pt, and an oxide. Further, for the purpose of improving SNR characteristics, the recording layer is made of Cr, B, Cu, Ta, Zr. It is preferable to add an element such as

Examples of the oxide when the recording layer 4 is a magnetic layer having a granular structure include SiO ₂ , SiO, Cr ₂ O ₃ , CoO, Ta ₂ O ₃ , and TiO ₂ . The volume ratio of these oxides is preferably 15 to 40% by volume. If the volume ratio of the oxide is less than 15% by volume, the SNR characteristic becomes insufficient, which is not preferable. When the volume ratio of the oxide exceeds 40% by volume, it is not preferable because a coercive force sufficient for a high recording density cannot be obtained.

  The nucleation magnetic field (-Hn) of the recording layer 4 is preferably 1.5 (kOe) or more. -Hn of less than 1.5 (kOe) is not preferable because thermal fluctuation occurs.

  The thickness of the recording layer 4 is preferably 6 to 18 nm. When the thickness of the oxide granular layer 4 is within this range, it is preferable because sufficient output can be secured and OW characteristics do not deteriorate.

  A mask layer 5 is formed on the recording layer 4. In the present invention, Si is used as the mask layer 5 containing Si. Si can easily form a high-purity and dense film by CVD or PVD, and can be easily removed without leaving a residue by etching using a dry process or the like. Si has poor wettability with respect to a resist, and is not suitable for fine photolithography processing using a resist. In the present invention, since a thin oxide film is formed on the surface of Si, wettability with a general resist material such as SOG can be improved.

  The stamper 9 used in the above-described imprint process is obtained by forming a fine track pattern on a metal plate using a method such as electron beam drawing, and the material is required to have hardness and durability that can withstand the imprint process. The For example, Ni or the like is used, but any material can be used as long as it meets the above purpose.

  As the resist 7 applied to the mask layer 5 formed on the continuous magnetic layer (recording layer) 4 described above, various types such as a photoresist widely used in industry can be used. Usually, SOG is applied thinly and uniformly using spin coating or the like, and then baked in an oven at a constant temperature for a desired processing time to remove unnecessary organic solvents and the like. With respect to this process, the process can be appropriately adjusted according to the properties of the resist 7 to be used.

  For the first etching process, methods such as reactive ion etching and ion milling can be used as appropriate. The recording layer 4 is completely cut to form a concave groove (part of the separation region) 11b, and then the resist 7 and the mask layer 5 remaining on the top of the recording layer 4 are peeled off by a second etching process. To remove.

  In the above-described embedding process, for example, a nonmagnetic material is used as the embedding material corresponding to the isolation region. Since it is necessary to uniformly fill the very fine and deep groove 11b with the non-magnetic material, what process conditions are used is important. A typical process is a sputtering method, but it is necessary to carefully select conditions such as deposition rate and gas pressure. If this embedding process is not performed accurately, the magnetic interaction between the recording parts is not sufficiently blocked, and sufficient recording / reproducing characteristics cannot be expected. Further, there is a concern that the gap portion may come into contact with a gas such as oxygen in the atmosphere and adversely affect the corrosion resistance.

  In the above-described planarization process, the unevenness of the medium surface that will occur after the embedding process is smoothed to a level sufficient for a magnetic recording medium. As this means, CMP (Chemical mechanical polish), IBE (Ion Beam Etching) or the like is used. As long as the surface of the medium can be processed sufficiently smoothly without impairing the performance of the medium, the effect of the present invention is not affected by any technique. However, in the present invention, the ion beam etching method, which is a dry process, is used. It is preferable in that the contamination of the etched surface can be reduced. In the present invention, it is effective to realize high-density magnetic recording that the flying height of the magnetic head is as small as possible. Accordingly, the surface roughness (Ra) in the magnetic recording medium of the present invention is preferably 1 nm or less, more preferably 0.5 nm or less, and particularly preferably 0.3 nm or less.

In the above manufacturing example, the recording layer 4 is physically separated, and the separation region is filled with a nonmagnetic material or the like to form a magnetic recording pattern. In the present invention, instead of such a manufacturing process, a patterned mask layer is provided on the surface of a continuous recording layer, and a portion (concave groove) not covered with the recording layer is exposed to reactive plasma, The present invention can also be applied to a process for forming a recording layer having a magnetic recording pattern that is magnetically separated by changing the magnetic characteristics of the portion. The manufacturing method of the present invention includes a method for manufacturing a magnetic recording medium in which such a recording layer is not physically processed.
In the above manufacturing example, a pattern is formed using a stamper as a resist. However, the present invention can also be applied to a magnetic recording medium in which a pattern is formed on a resist using a photolithography technique. it can.

Finally, the protective film 16 is formed. In general, a thin film of DLC (Diamond Like Carbon) is formed using P-CVD or the like, but the method is not limited to this. The protective film here may be considered to be the same as that generally used as a magnetic recording medium protective film. As the protective film, other commonly used protective film materials such as carbonaceous layers such as C, hydrogenated C, nitrogenated C, alumophus C, and SiC, and SiO ₂ , Zr ₂ O ₃ , and TiN can be used. Further, the protective film 16 described above may be composed of two or more layers. The thickness of the protective film is 1 to 10 nm, particularly 1 to 5 nm, and it is preferable to set it as thin as possible within a range in which durability can be secured.

  A lubricating layer 17 is formed on the protective film 16. Examples of the lubricant used for the lubricant layer 17 include a fluorine-based lubricant, a hydrocarbon-based lubricant, and a mixture thereof, and the lubricant layer is usually formed with a thickness of 1 to 4 nm.

  A magnetic recording / reproducing apparatus according to the present invention includes at least a magnetic recording medium A having the above-described structure, a driving unit that drives the magnetic recording medium A in a recording direction, a magnetic head including a recording unit and a reproducing unit, and a magnetic head with respect to the magnetic recording medium. And a recording / reproduction signal processing means for performing signal input to the magnetic head and reproduction of the output signal from the magnetic head.

  Furthermore, by configuring the reproducing section of the magnetic head as a GMR head or TMR head, a sufficient signal intensity can be obtained even at a high recording density, and a magnetic storage device having a high recording density can be realized. . When this magnetic head is floated at a flying height of 0.005 μm to 0.020 μm, which is lower than the conventional height, the output is improved and a high device S / N is obtained, and a large capacity and highly reliable magnetic field is obtained. A storage device can be provided. Further, the recording density can be further improved by combining the signal processing circuit based on the maximum likelihood decoding method. For example, recording / reproducing is performed at a recording density of 100 Gbit / inch or more per square inch, with a track density of 100 kTPI or more, a linear recording density of 1000 kbpI or more. In some cases, sufficient S / N can be obtained.

  More specifically, a magnetic recording / reproducing apparatus is configured as shown in FIG. The magnetic recording / reproducing apparatus B of this example shown in FIG. 3 has a rectangular box-shaped housing 21 whose upper surface is open and a top cover (not shown) that closes the opening of the housing 21.

  In the housing 21, the magnetic recording medium 22 having the above-described configuration, a spindle motor 23 as a driving means for supporting and rotating the magnetic recording medium 22, and recording and reproduction of magnetic signals with respect to the magnetic recording medium 22 are performed. A magnetic head 24 (single magnetic pole head), a head actuator 25 having a suspension with the magnetic head 24 mounted at the tip, and supporting the magnetic head 24 movably with respect to the magnetic recording medium 22, and a head actuator 25 being rotatably supported A rotating shaft 26 that rotates, a voice coil motor 27 that rotates and positions the head actuator 25 via the rotating shaft 26, and a head amplifier circuit 28 are housed.

A vacuum chamber in which a cleaned glass substrate for HD (Ohara Co., Ltd., outer diameter 0.85 inch) was set was evacuated to 1.0 × 10 ⁻⁵ Pa or less in advance. Further, 65Fe-25Co-10B (atomic%) was deposited on the substrate at 50 nm without heating, Ru was 0.8 nm, and then 65Fe-25Co-10B (atomic%) was deposited at 50 nm to form a soft magnetic backing layer.

Subsequently, an orientation control layer made of Ru was formed to 20 nm, a recording layer made of 65Co-10Cr-15Pt-10SiO ₂ (atomic%) was formed to 12 nm, and a mask layer made of Si was formed to 4 nm.

  Next, the surface of the mask layer was exposed to a reactive plasma containing oxygen to form an oxide film having a thickness of about 1 nm on the surface of the mask layer. The medium was taken out from the vacuum chamber, and an SOG resist was applied to the surface by spin coating. After application, the excess solvent was removed by baking for 20 minutes in a constant temperature bath at about 100 ° C.

  Next, imprinting was performed using a Ni stamper prepared in advance. The stamper was formed with concentric concave grooves having a track pitch of 150 nm.

  Next, this sample was set in a high vacuum chamber, and the recording film including the recording layer in each concentric concave groove (annular groove corresponding to the separation region) was removed by ion beam etching.

Thereafter, as the non-magnetic material by an RF sputtering method, 40Co-35Cr-15Pt-10SiO 2 ( atomic%) film was deposited (i.e., filled with non-magnetic material in each groove-shaped separation region). The average film thickness of this film was adjusted to 80 nm.

  Further, ion beam etching was used to expose the recording layer in each track portion, and the surface was smoothed to the point where the surface was etched by about 1 nm. Finally, a DLC film having a thickness of 4 nm was formed by a CVD method, and a lubricant was applied to a thickness of 2 nm to produce a magnetic recording medium. This sample magnetic recording medium is taken as an example.

(Comparative Example 1)
A magnetic recording medium was manufactured according to the above-described example except that the surface of the mask layer was not oxidized.

(Comparative Example 2)
A magnetic recording medium was manufactured according to the above-described example except that the Si mask layer was not provided on the surface of the recording layer. In this comparative example, SOG contacts the recording layer, and the patterned SOG functions as a mask layer.

(Comparative Example 3)
A magnetic recording medium was produced according to the above-described example except that carbon was used as the mask layer.

Glide evaluation was performed on the magnetic recording media manufactured in Examples and Comparative Examples 1 to 3. The results are shown in Table 1. In the glide evaluation, the surface of the magnetic recording medium was scanned with a flying height of 5 nm using a head with an impact sensor, and the number of protrusions detected by the head was compared. The magnetic recording medium produced by the production method of the present invention had no glide hit and had a smooth surface.

1A and 1B show a method of manufacturing a magnetic recording medium according to the present invention. FIG. 1A is a cross-sectional view showing a state where a recording layer is formed on a substrate, and FIG. 1B is a cross-sectional view showing a state where a resist is formed. FIG. 1C is a cross-sectional view showing a state imprinted by a stamper, and FIG. 1D is a cross-sectional view showing a state where a recess is removed by etching. 2A and 2B show a method for manufacturing a magnetic recording medium according to the present invention, in which FIG. 2E is a cross-sectional view showing a state in which a convex upper layer is removed by etching, and FIG. 2F is a cross-sectional view showing a state in which a deposited layer is formed. FIG. 2 (G) is a cross-sectional view showing a state where the surface is smoothed, FIG. 2 (H) is a cross-sectional view showing a state where a protective film is formed, and FIG. 2 (I) shows a state where a lubricating layer is formed. It is sectional drawing. It is a block diagram which shows an example of the magnetic recording / reproducing apparatus based on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Nonmagnetic substrate 2 Soft magnetic backing layer 3 Orientation control layer 4 Recording layer 5 Mask layer 6 Laminated structure 7 Resist 8 Medium 9 Stamper 11 Concavity and convexity part 11a Convex part 11b Concave groove 12 Deposition layer 13 Smooth surface 14 Separation area 15 Bit part 15 Recording track portion 16 Protective film 17 Lubricating layer 22 Magnetic recording medium 23 Spindle motor 24 Magnetic head 25 Head actuator 26 Rotating shaft 27 Voice coil motor 28 Head amplifier circuit A Perpendicular magnetic recording medium B Magnetic recording / reproducing apparatus

Claims (5)

In a magnetic recording medium manufacturing method for manufacturing a magnetic recording medium having at least a magnetically separated recording layer on a nonmagnetic substrate,
Forming a recording layer on the non-magnetic substrate;
Forming a mask layer containing Si on the recording layer;
Oxidizing the surface of the mask layer;
Forming a resist layer on the oxidized surface of the mask layer;
Patterning the resist layer to form a concavo-convex pattern on the mask layer;
Magnetically separating the recording layer using the concave / convex pattern of the mask layer;
Removing the mask layer;
A method for producing a magnetic recording medium, comprising:   The method for manufacturing a magnetic recording medium according to claim 1, wherein the mask layer containing Si is made of Si.   3. The method of manufacturing a magnetic recording medium according to claim 1, wherein the patterning of the resist layer is performed by an imprint method using a stamper.   A magnetic recording medium manufactured by the manufacturing method according to claim 1.   A magnetic recording / reproducing apparatus comprising a magnetic recording medium and a magnetic head for recording / reproducing information on the magnetic recording medium, wherein the magnetic recording medium is the magnetic recording medium according to claim 4. Magnetic recording / reproducing device.

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