JP2002063718A - Method for manufacturing perpendicular magnetic recording medium, perpendicular magnetic recording medium, and perpendicular magnetic recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to form a base film having a granular structure of a state where that magnetic particles are held in a spherical shape. SOLUTION: The method for manufacturing a perpendicular magnetic recording medium has a stage for forming a base film layer 2 having a granular structure wherein the magnetic particles 2b are dispersed in a non-magnetic base material 2a on a substrate 1, a stage for forming a perpendicular magnetic layer 3 on the base film layer 2 and a stage for forming a protective film layer 4 on the perpendicular magnetic layer 3. And the base film layer having a layer structure wherein the magnetic particles 2b are arrayed in a direction perpendicular to the base film layer 2 in plural rows is formed by forming the base film layer 2 while substrate bias are intermittently applied to the substrate 1, in the stage for forming the base film layer 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for manufacturing a perpendicular magnetic recording medium capable of performing low-noise and high-density recording, a perpendicular magnetic recording medium, and a perpendicular magnetic recording apparatus.

[0002]

2. Description of the Related Art In recent years, magnetic recording devices have been widely used as external recording devices in electronic devices such as personal computers. In this magnetic recording apparatus, further increase in areal recording density is required, and accordingly, a perpendicular magnetic film having an easy axis of magnetization in a direction perpendicular to the running direction of the magnetic recording medium is provided, and a magnetic head is provided. A perpendicular magnetic recording method for applying a magnetic field in the perpendicular direction of a perpendicular magnetic film to record a magnetic signal has been studied. In addition, a method of obtaining a more excellent recording / reproducing characteristic by an interaction between a magnetic head and a base film by providing a base layer having high magnetic permeability under the perpendicular magnetic film to form a two-layer structure is being studied. Here, when the underlying film has a structure in which a domain wall is generated, the movement and fluctuation of the domain wall existing in the underlying film occur due to the influence of the magnetic field generated from the spindle motor, the voice coil motor, and the like. It is known that a problem arises in that recording and degaussing and rewriting of the magnetic signal of the upper perpendicular magnetic film occur.

In order to solve this problem, the structure of a base film has been studied.
In Japanese Patent Publication No. 28, the underlayer film is made of Co, C
It describes a method of forming a granular structure in which magnetic particles of a hard magnetic material such as oPt and CoCrPt are dispersed to exhibit soft magnetic characteristics and prevent a domain wall from forming a domain wall.

However, when magnetic particles of a hard magnetic material are used for the underlayer as in this prior art, Hco (Dynamic) which is a magnetic characteristic which is not affected by thermal fluctuation which is affected during high-speed magnetization reversal performed during actual recording. coair
Sivity) shows the same hard magnetism as the magnetic particles of the hard magnetic material. That is, when recording a magnetic signal, it is not possible to record a magnetic signal at high density on the perpendicular magnetic film due to the effect of the high anisotropic magnetic field Hk of the magnetic particles of the hard magnetic material in the underlayer. Further, since the magnetic particles of the hard magnetic material have a small value of the saturation magnetic flux density Bs, when the magnetic particles of the hard magnetic material have a granular structure, the magnetic particles are required to act as a soft magnetic film with respect to the perpendicular magnetic film. In order to obtain the saturation magnetic flux density Bs, the film thickness must be formed very thick.

On the other hand, the present inventor has disclosed in Japanese Patent Application No. 11-2774.
No. 50, a soft magnetic material is used instead of a hard magnetic material as a magnetic particle used for a base film, and CoFe, NiF having a large saturation magnetic flux density Bs and a high magnetic permeability.
e, there has been proposed a perpendicular magnetic recording medium capable of recording a magnetic signal with high density by using a soft magnetic material such as CoZrNb.

[0006]

However, in the granular structure, the volume content of the magnetic particles is lower than that of the continuous film. In order to obtain a saturation magnetic flux density Bs sufficient for recording a magnetic signal on the magnetic film, it is necessary to increase the film thickness to some extent. In general, when a base film having a granular structure of magnetic particles of a hard magnetic material or a soft magnetic material is formed on a substrate, a substrate bias is applied to the substrate so that the magnetic particles grow. This is performed by physically depositing a material for a base film thereon.

However, this conventional method has a disadvantage that when a thick underlayer is formed, magnetic particles of a hard magnetic material or a soft magnetic material grow in columns in a direction perpendicular to the underlayer. Was. If the magnetic particles have a columnar shape in the vertical direction, the underlying film will exhibit vertical anisotropy. Cannot be recorded.

Therefore, the present invention makes it possible to form a base film having a granular structure in which magnetic particles are kept in a spherical shape, thereby enabling recording of a magnetic signal with low noise and high density. It is an object of the present invention to provide a method for manufacturing a perpendicular magnetic recording medium, a perpendicular magnetic recording medium, and a perpendicular magnetic recording device capable of manufacturing a perpendicular magnetic recording medium.

[0009]

According to the present invention, there is provided a method of manufacturing a perpendicular magnetic recording medium, comprising the steps of: forming a base film layer having a granular structure in which magnetic particles are dispersed in a non-magnetic base material on a substrate; Forming a perpendicular magnetic layer on the underlying film layer, and forming a protective film layer on the perpendicular magnetic layer, the step of forming the underlying film layer, By forming the base film layer while applying a substrate bias intermittently to the substrate, a base film layer having a layer structure in which the magnetic particles are arranged in a plurality of rows in the vertical direction of the base film layer is formed. It is characterized by the following.

[0010] The perpendicular magnetic recording medium of the present invention comprises a substrate, an underlayer formed on the substrate, a perpendicular magnetic layer formed on the underlayer, and a perpendicular magnetic layer formed on the underlayer. In the perpendicular magnetic recording medium having a protective film layer provided, the underlayer film has a granular structure in which magnetic particles are dispersed in a non-magnetic base material, and a plurality of the magnetic particles are arranged in a direction perpendicular to the underlayer film layer. Are characterized by a layered structure arranged in a row.

Further, the perpendicular magnetic recording / reproducing apparatus of the present invention comprises:
A perpendicular magnetic recording medium, a spindle motor for supporting and rotating the perpendicular magnetic recording medium, and a magnetic head for recording a magnetic signal on the perpendicular magnetic recording medium and reproducing a magnetic signal recorded on the perpendicular magnetic recording medium The perpendicular magnetic recording / reproducing apparatus comprising: a perpendicular magnetic recording medium comprising: a substrate; a base film layer formed on the substrate; a perpendicular magnetic layer formed on the base film layer; A protective film layer formed on the magnetic layer, wherein the underlayer film has a granular structure in which magnetic particles of a soft magnetic material are dispersed in a non-magnetic base material; Has a layer structure arranged in a plurality of rows in the vertical direction of the base film layer.

With the above structure, it is possible to realize a perpendicular magnetic recording medium having a thick underlayer while maintaining the shape of the magnetic particles in a spherical shape. It is possible to provide a perpendicular magnetic recording device.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (Perpendicular Magnetic Recording Medium) Embodiments of the present invention will be described below with reference to the drawings.

First, a perpendicular magnetic recording medium manufactured by the manufacturing method of the present invention will be described. FIG. 1 is a sectional view of a perpendicular magnetic recording medium manufactured by the manufacturing method of the present invention. The perpendicular magnetic recording medium of the present invention has a structure in which a substrate 1, a soft magnetic underlayer 2, a perpendicular magnetic film 3, and a protective film 4 are sequentially laminated.

As a material of the substrate 1, glass, silicon, plastic, synthetic resin and the like can be used. As a method for forming the soft magnetic underlayer 2 and the perpendicular magnetic film 3 on the substrate 1, it is possible to use a physical vapor deposition method such as a sputtering method, a vacuum vapor deposition method, an in-gas sputtering method, and a gas flow sputtering method. . As the magnetic material of the soft magnetic underlayer 2, a soft magnetic material containing at least one element selected from Co, Fe, and Ni, for example, CoFe, NiF
e, CoZrNb or the like can be used. As the non-magnetic base material of the soft magnetic underlayer 2, a non-magnetic metal such as Ag, Ti, Ru, C or a compound thereof, or an oxide, a nitride, a fluoride, a carbide, for example, SiO2, SiO, Si3N4,
Al2O3, AlN, TiN, BN, CaF, TiC or the like is used.

FIG. 2 is a diagram schematically showing a portion of the perpendicular magnetic recording medium shown in FIG. 1 which is indicated by a region A of the soft magnetic underlayer 2 and the perpendicular magnetic film 3. As shown in FIG. 2, in the perpendicular magnetic film 3, a magnetic signal is recorded in a vertical direction as schematically indicated by an arrow.
The soft magnetic underlayer 2 provided below the perpendicular magnetic film 3 has a granular structure in which magnetic particles 2b of a soft magnetic material are uniformly dispersed in a nonmagnetic base material 2a.

Next, a method of manufacturing the perpendicular magnetic recording medium of FIG. 1 will be described below.

(Method of Manufacturing First Perpendicular Magnetic Recording Medium) The first perpendicular magnetic recording medium is manufactured as follows. That is, on a substrate 1 of 2.5 inch glass, Co80F
Using a composite target in which the volume composition ratio of e20 and TiN after film formation was adjusted to be 60:40, a granular structure having TiN as the non-magnetic base material 2a and Co80Fe20 as the magnetic particles 2b was formed by facing static magnetron sputtering. A soft magnetic underlayer 2 was formed. When the soft magnetic underlayer 2 is formed, first, the substrate bias 4 is applied to the substrate 1.
While applying 00 [W], a composite target is sputtered on the substrate 1 in an Ar gas atmosphere at a sputtering power of 1000 [W] for 20 [sec] to form a film.
A lower portion of the soft magnetic underlayer 2 where the first row of the magnetic particles 2b of the soft magnetic material exists (the lower side of the two-dot chain line in FIG. 2) is formed. Then, 5 is applied to the substrate 1 without applying a substrate bias.
[Sec] A film is formed by sputtering. Subsequently, while applying a substrate bias of 400 [W] to the substrate 1 again, 20
[Sec] A film is formed by sputtering, and an upper portion (above the two-dot chain line in FIG. 2) of the soft magnetic underlayer 2 in which the next row of the magnetic particles 2b of the soft magnetic material exists. In this way,
An 80 [nm] soft magnetic underlayer 2 is formed.

Continuously on the soft magnetic underlayer 2 formed,
Using a CoPt20Cr16 alloy target, CoPt20C
An r16 perpendicular magnetic film 3 was formed to a thickness of 50 [nm]. Finally, an 8 [nm] C protective film 4 is formed.

(Method of Manufacturing the Second Perpendicular Magnetic Recording Medium) In the first perpendicular magnetic recording medium, TiN is used for the nonmagnetic base material 2a, whereas the second perpendicular magnetic recording medium is The difference is that SiO2, which is an insulating material, is used as the base material 2a.

The second perpendicular magnetic recording medium is manufactured as follows. That is, using a composite target adjusted so that the volume composition ratio of Co80Fe20 and SiO2 after film formation is 60:40 on a 2.5-inch glass substrate 1, SiO 2 was deposited by a facing stationary magnetron sputtering method.
2 is a non-magnetic base material 2a, Co80Fe20 is a magnetic particle 2b.
A soft magnetic underlayer 2 having a granular structure is formed.
In forming the soft magnetic underlayer 2, the substrate bias to the substrate 1 is applied twice and intermittently in the same manner as in the first manufacturing method described above. That is, first, a sputtering power of 1000 [W] is applied to the substrate 1 in an Ar gas atmosphere while applying a substrate bias of 400 [W] to the substrate 1.
As a result, a composite target is sputtered for 20 [sec] to form a film, and then the substrate 1 is sputtered for 5 [sec] without applying a substrate bias to the substrate 1, and subsequently, a substrate bias 400 is applied to the substrate 1 again. A film is formed by sputtering for 20 [sec] while applying [W]. Thus, the soft magnetic underlayer 2 of 80 [nm] is formed.

Continuously on the soft magnetic underlayer 2 formed,
Using a CoPt20Cr16 alloy target, CoPt20C
The perpendicular magnetic film 3 of r16 is formed to a thickness of 50 [nm]. Finally, an 8 [nm] C protective film 4 is formed.

As a comparative example for comparing magnetic properties and the like with the first and second perpendicular magnetic recording media, a perpendicular magnetic recording medium formed without applying a substrate bias when forming a soft magnetic underlayer was used. Was manufactured. The perpendicular magnetic recording medium of the comparative example
The layers other than the soft magnetic underlayer were formed by the same method as the first and second perpendicular magnetic recording media.

(Measurement of Magnetic Properties) Next, regarding the first and second perpendicular magnetic recording media of the present invention and the perpendicular magnetic recording media of the comparative example manufactured by the above-described manufacturing method, the magnetic properties of the respective soft magnetic underlayers were measured. The characteristics were measured and compared. When measuring the magnetic characteristics, only the soft magnetic underlayer was formed by the above-described method for each of the first and second perpendicular magnetic recording media of the present invention and the perpendicular magnetic recording media of the comparative example.
SM (Vibrating SampleMagnet)
measurement). FIG. 3 shows the measurement results of the magnetic properties. As for the coercive force Hc, the soft magnetic underlayer of the first perpendicular magnetic recording medium of the present invention was 87 [A /
m], the soft underlayer of the second perpendicular magnetic recording medium is 79
[A / m], the soft magnetic underlayer of the perpendicular magnetic recording medium of the comparative example was as low as 40 [A / m], and the magnetic permeability μ was as high as 1000 or more. It can be seen that both the soft magnetic underlayer of the perpendicular magnetic recording medium of No. 2 and the soft magnetic underlayer of the perpendicular magnetic recording medium of the comparative example show soft magnetic characteristics.

However, comparing the values of Mr / Ms, the soft magnetic underlayers of the first and second perpendicular magnetic recording media of the present invention have low values of 0.52 and 0.6, respectively, and the magnetic particles are small. It is conceivable that the perpendicular magnetic recording medium of the comparative example has a soft magnetic underlayer as high as 0.85, and the magnetic particles have a columnar shape extending in the film thickness direction. It is considered that the shape is as follows.

Further, both the soft magnetic underlayers of the first and second perpendicular magnetic recording media of the present invention are as shown in FIG.
The fact that the remanent magnetization Mr is small and the portion from the saturation magnetization Ms to the remanent magnetization Mr of the magnetization curve is a Stoner-Wohlfarth type curve-like magnetic characteristic was measured. It is considered that the magnetic particles of both the soft magnetic underlayer of the second perpendicular magnetic recording medium and the soft magnetic underlayer are spherical or spheroidal.

On the other hand, in the soft magnetic underlayer film of the comparative example, as shown in FIG. 5, since a magnetization curve showing a perpendicular anisotropy is obtained, it is considered that the magnetic particles have a columnar shape.

(Observation of Film Structure) Further, regarding the soft magnetic underlayers of the first and second perpendicular magnetic recording media of the present invention and the perpendicular magnetic recording media of the comparative example, soft magnetic magnetic particles were formed in the films. In order to confirm whether the particles are uniformly dispersed and whether the soft magnetic particles are growing spherically, a TEM
(Transmission Electron Sp
(Electroscopy) was used to observe the film structure.

First, the film structure of the soft magnetic underlayers of the first and second perpendicular magnetic recording media of the present invention in the plane direction (the plane direction shown in FIG. 2) was observed. It was observed that the magnetic particles of the spherical soft magnetic material were uniformly dispersed. In addition, the particle diameter of the magnetic particles is about 15 to 20 [nm], and the effect of applying a substrate bias during the formation of the soft magnetic underlayer promotes the particle growth of the magnetic particles. It is thought that it became.

Next, when the film structure in the vertical direction (vertical direction shown in FIG. 2) was observed, the first and second films of the present invention were observed.
Each of the soft magnetic underlayers of the perpendicular magnetic recording medium has a layer structure in which the magnetic particles are spherical or spheroidal, and the magnetic particles are vertically arranged in two rows as shown in FIG. It was confirmed that. This is because the application of the substrate bias is temporarily interrupted during the formation of the soft magnetic underlayer. That is, by temporarily interrupting the application of the substrate bias, the grain growth is suppressed before the magnetic particles of the first-stage magnetic material grow in a columnar shape, and thereafter, the substrate bias is applied again to perform the two-stage application. This is because the magnetic particles of the eye magnetic material are allowed to grow.

As described above, in the first and second perpendicular magnetic recording media of the present invention, when the soft magnetic underlayer is formed, the substrate bias is intermittently applied to the substrate in two steps, so that the The particles have a layer structure in which the particles do not grow in a columnar direction in the cross-sectional direction but are arranged in two rows in the cross-sectional direction, and the particle diameter of the magnetic particles can be increased by the effect of promoting the aggregation of the magnetic particles.

On the other hand, when the film structure of the comparative example was observed, the film structure in the planar direction showed that although the magnetic particles were uniformly dispersed in the non-magnetic base material and had a granular structure, Since no substrate bias was applied during the formation of the underlayer, the grain growth of the magnetic grains was about 10 to 13 [nm] without promoting the grain growth, and the first and second perpendicular magnetic recording of the present invention were performed. It was confirmed that it was smaller than the medium. Further, it was confirmed that the magnetic film in the vertical direction had a shape in which magnetic particles were grown in a columnar shape in the vertical direction as shown in FIG.

(Measurement of Noise Characteristics) Next, the first aspect of the present invention will be described.
The noise characteristics of each of the second perpendicular magnetic recording medium and the perpendicular magnetic recording medium of the comparative example were examined. At the time of noise measurement, a GMR head having a read gap length of 0.15 [μm] and a read track width of 0.8 [μm] and a main magnetic pole film pressure of 0.4 were used.
The measurement was performed using a single pole type head having a recording track width of 2 [μm] and a flying height of 20 [nm] using a spin stand.

First, the DC noise of only the soft magnetic underlayer of the first and second perpendicular magnetic recording media of the present invention (provided that the protective film is provided) was measured. As a result, no spike noise was measured in either case, and it was confirmed that no domain wall was present in the soft magnetic underlayer.

Next, with respect to the entire perpendicular magnetic recording medium (in which not only the soft magnetic underlayer but also the layers from the substrate to the protective film are laminated), a recording density of 30% is applied to the perpendicular magnetic film.
Normalized medium noise Nm / when recording at 0 [kfci]
SO was measured. As a result, in both cases, the normalized medium noise Nm / SO = 0.015 [μm1 / 2 μVrms / μ
Vpp] and its value are small, and it can be seen that the noise is reduced.

On the other hand, the DC noise of only the soft magnetic underlayer of the perpendicular magnetic recording medium of the comparative example was measured. As a result, no spike noise was measured and no domain wall was confirmed. In the measurement result of the normalized medium noise for the whole, the value is Nm / SO = 0.0
22 [μm1 / 2 μVrms / μVpp], the first
And a value larger than that of the second perpendicular magnetic recording medium.
This is because in the comparative example, the soft magnetic underlayer had a granular structure in which magnetic particles were dispersed, and thus no magnetic domain wall was present. This is probably due to the appearance of vertical anisotropy in the ground film.

In the first and second methods for manufacturing a perpendicular magnetic recording medium, the substrate bias is intermittently applied to the substrate in two separate steps during the formation of the soft magnetic underlayer. However, the present invention is not limited to this, and in order to further increase the thickness of the soft magnetic underlayer or to increase the number of magnetic particles, the substrate bias may be intermittently applied in three or more steps. When the substrate bias is intermittently applied in three times, three spherical magnetic particles are formed in the vertical direction of the soft magnetic underlayer.
The layer structure is arranged in a line. Even in the case of four or more times, it is conceivable that the magnetic layer has a layered structure in which spherical magnetic particles are arranged in the vertical direction of the soft magnetic underlayer by the number of columns corresponding to the number of times of application of the substrate bias.

As described above, when the soft magnetic underlayer is formed, the substrate bias is divided and applied intermittently a plurality of times, so that the thickness of the soft magnetic underlayer can be reduced while the shape of the magnetic particles is kept spherical. This makes it possible to increase the thickness of the recording medium, thereby realizing a low-noise perpendicular magnetic recording medium having a small normalized medium noise Nm / SO.

(Measurement of Resolution) Next, in order to compare the high-frequency recording characteristics of the first and second perpendicular magnetic recording media of the present invention due to the difference in the non-magnetic base material in the soft magnetic underlayer, the respective perpendicular magnetic films were compared. Recording density 400 [kfc
i] and the resolution PW50 at the time of recording was measured. As a result, as shown in FIG. 3, the resolution PW50 of the first perpendicular magnetic recording medium was about 12 [nSec], and the resolution PW50 of the second perpendicular magnetic recording medium was about 10 [nSec].
That is, since the second perpendicular magnetic recording medium has a resolution PW50 about 10% smaller than that of the first perpendicular magnetic recording medium, the second perpendicular magnetic recording medium is superior to high-frequency recording.

Here, the electric resistivity ρ of the surface of the soft magnetic underlayer of the first and second perpendicular magnetic recording media was measured by the four-terminal method, and the soft magnetic underlayer of the first perpendicular magnetic recording medium was measured. Is the electric resistivity ρ = 〜500 [μΩm], and the soft magnetic underlayer of the second perpendicular magnetic recording medium has the electric resistivity ρ = 〜1000 [μm].
Ωm], indicating that the soft magnetic underlayer of the second perpendicular magnetic recording medium has higher electric resistance. That is, by using a material having a high electric resistance such as SiO2 as the non-magnetic base material to increase the resistance of the soft magnetic underlayer, the generation of eddy current on the surface of the soft magnetic underlayer can be reduced, and the high frequency recording is more excellent. Perpendicular magnetic recording medium can be obtained.

(Perpendicular Magnetic Recording Apparatus) Next, the configuration of a perpendicular magnetic recording apparatus using the above-described perpendicular magnetic recording medium will be described.

FIG. 7 is a schematic view of a perpendicular magnetic recording apparatus according to the present invention. As shown in FIG. 7, the perpendicular magnetic recording apparatus of the present invention comprises a housing 26 on a rectangular box having an open top,
A top cover (not shown) that closes an upper end opening of the housing that is screwed to the housing 26 with a plurality of screws. Inside the housing 26, a perpendicular magnetic recording medium 22 using the above-described first or second perpendicular magnetic recording medium, a spindle motor 21 as a driving means for supporting and rotating the perpendicular magnetic recording medium 22, a perpendicular magnetic recording medium A magnetic head 23 for recording a magnetic signal on the medium 22 and reproducing a magnetic signal recorded on the perpendicular magnetic recording medium 22;
Head actuator 24, which supports the magnetic recording medium 3 movably with respect to the perpendicular magnetic recording medium 22,
, A voice coil motor 27 for rotating and positioning the head actuator 24 via the rotary shaft 28, and a head amplifier circuit 25 are housed.

As described above, by using the first or second perpendicular magnetic recording medium of the present invention as the perpendicular magnetic recording medium 22, it is possible to realize a perpendicular magnetic recording medium capable of performing high-density recording with low noise. Is possible.

[0044]

As described above in detail, according to the present invention, it is possible to realize a perpendicular magnetic recording medium having a thick underlayer film while keeping the shape of the magnetic particles spherical, and therefore low noise. In addition, it is possible to provide a perpendicular magnetic recording medium and a perpendicular magnetic recording device for high-density recording.

[Brief description of the drawings]

FIG. 1 is a diagram showing a cross-sectional configuration of first and second perpendicular magnetic recording media of the present invention.

FIG. 2 is a partially enlarged schematic diagram of a perpendicular magnetic film and a soft magnetic underlayer of first and second perpendicular magnetic recording media of the present invention.

FIG. 3 is a diagram showing a magnetic characteristic table of first and second perpendicular magnetic recording media of the present invention and a perpendicular magnetic recording medium of a comparative example.

FIG. 4 is a diagram showing a magnetization curve of a soft magnetic underlayer of the first and second perpendicular magnetic recording media of the present invention.

FIG. 5 is a diagram showing a magnetization curve of a soft magnetic underlayer of a perpendicular magnetic recording medium of a comparative example.

FIG. 6 is a partially enlarged schematic view of a perpendicular magnetic film and a soft magnetic underlayer of a perpendicular magnetic recording medium of a comparative example.

FIG. 7 is a diagram showing an example of a perpendicular magnetic recording device according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Substrate 2 ... Soft magnetic base film 2a ... Non-magnetic base material 2b ... Magnetic particles of soft magnetic material 3 ... Perpendicular magnetic film 4 ... Protective film 11 ... Soft magnetic base film 11a ... Non-magnetic base material 11b ... Soft magnetic material Magnetic particles 12 ... Perpendicular magnetic film 21 ... Spindle motor 22 ... Perpendicular magnetic recording medium 23 ... Magnetic head 24 ... Head actuator 25 ... Head amplifier circuit 26 ... Housing 27 ... Voice coil motor 28 ... Rotating axis

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4K029 BA24 BA64 BB02 BB07 BC06 BD11 CA05 CA13 5D006 CA01 CA03 CA05 5D112 AA03 BD01 BD03 FA04 FB26

Claims (7)

[Claims] 1. A step of forming a base film layer having a granular structure in which magnetic particles are dispersed in a nonmagnetic base material on a substrate, and a step of forming a perpendicular magnetic layer on the base film layer And a step of forming a protective film layer on the perpendicular magnetic layer, wherein the step of forming the underlayer film layer comprises intermittently applying a substrate bias to the substrate to form the underlayer film layer. A method for manufacturing a perpendicular magnetic recording medium, comprising forming a film on a base film layer having a layer structure in which the magnetic particles are arranged in a plurality of rows in a direction perpendicular to the base film layer. 2. The step of forming the underlayer film, wherein the nonmagnetic base material is a material selected from nonmagnetic metals, compounds of the nonmagnetic metals, oxides, nitrides, fluorides, and carbides. 2. The method for manufacturing a perpendicular magnetic recording medium according to claim 1, wherein 3. The method according to claim 1, wherein in the step of forming the underlayer, a soft magnetic material containing at least one selected from Co, Fe, and Ni is used as the magnetic particles. 3. The method for manufacturing a perpendicular magnetic recording medium according to item 2. 4. A perpendicular magnetic field comprising: a substrate; a base film layer formed on the substrate; a perpendicular magnetic layer formed on the base film layer; and a protective film layer formed on the perpendicular magnetic layer. In the recording medium, the base film layer has a granular structure in which magnetic particles are dispersed in a nonmagnetic base material, and has a layer structure in which the magnetic particles are arranged in a plurality of rows in a direction perpendicular to the base film layer. A perpendicular magnetic recording medium characterized by the above-mentioned. 5. The non-magnetic base material of the under film layer is made of a material selected from a non-magnetic metal, a compound of the non-magnetic metal, an oxide, a nitride, a fluoride, and a carbide. The perpendicular magnetic recording medium according to claim 4, wherein 6. The perpendicular magnetic recording according to claim 4, wherein a soft magnetic material containing at least one selected from Co, Fe, and Ni is used as the magnetic particles of the underlayer. Medium. 7. A perpendicular magnetic recording medium, a spindle motor for supporting and rotating the perpendicular magnetic recording medium, recording a magnetic signal on the perpendicular magnetic recording medium, and transmitting a magnetic signal recorded on the perpendicular magnetic recording medium. A perpendicular magnetic recording / reproducing apparatus comprising: a magnetic head for performing reproduction; wherein the perpendicular magnetic recording medium comprises a substrate, a base film layer formed on the substrate, and a perpendicular magnetic layer formed on the base film layer. And a protective film layer formed on the perpendicular magnetic layer,
In addition, the undercoat layer has a granular structure in which magnetic particles of a soft magnetic material are dispersed in a nonmagnetic matrix, and the magnetic particles of the soft magnetic material are arranged in a plurality of rows in a direction perpendicular to the undercoat layer. A perpendicular magnetic recording / reproducing apparatus characterized by having a layered structure.