JP2000057569A - Production of magnetic recording medium and magnetic recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a producing method of a magnetic recording medium having a magnetic layer more increased in coercive force and to provide the producing method of the magnetic recording medium more lighter in weight at a lower cost than that in the case of using a glass substrate. SOLUTION: The producing method contains (a) a process of depositing a non-magnetic oxide layer 2 by sputtering on a non-magnetic organic substrate 1, (b) a process of depositing a non-magnetic close contact layer 3 by sputtering on the oxide layer 2, (c) a process of depositing a nickel-phosphorus alloy layer 4 by sputtering on the close contact layer 3 and (d) a process of depositing a magnetic layer 5 by sputtering in an Ar atmosphere having the gas pressure of 10-50 mTorr at the depositing rate of 0.05-1.5 nm/sec on the nickel-pbosphorus alloy layer 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for manufacturing a magnetic recording medium, and more particularly to a method for manufacturing a magnetic recording medium having a magnetic layer with a high coercive force.

[0002]

2. Description of the Related Art A magnetic disk such as a hard disk drive (HDD) is required to have a higher recording density. In order to increase the recording density of the magnetic disk, it is necessary to increase the coercive force as well as the noise of the magnetic recording medium.
In order to increase the coercive force of the magnetic recording medium, it is effective to reduce the magnetic interaction between the magnetic crystal grains inside the magnetic layer and magnetically isolate each magnetic crystal grain.

As one of the methods for magnetically isolating magnetic crystal grains, a method of segregating a non-magnetic substance between magnetic crystal grains or at crystal grain boundaries is known.

For example, using a CoCr alloy for the magnetic layer,
Cr is segregated between crystal grains. Cr is antiferromagnetic and macroscopically behaves like a non-magnetic material. Further, when the magnetic layer deposition, SiO ₂ is co-deposited, a method to segregate the SiO ₂ in the crystal grain boundary is known. The method of segregating these non-magnetic materials between crystal grains or at crystal grain boundaries is widely used in current magnetic recording media.

As another method of magnetically isolating magnetic crystal grains, a method of forming magnetic crystal grains by spatially separating the magnetic crystal grains themselves is known. For example, a method is known in which a base layer having a relatively large surface roughness is formed, a magnetic layer is deposited thereon, and magnetic crystal grains formed thereon are spatially separated by using the unevenness of the base layer. Have been. A NiP alloy is known as a material for forming a surface having relatively large irregularities.

[0006] When a NiP alloy is used as a base of a magnetic layer, high crystal magnetic anisotropy is induced in the in-plane direction of the magnetic layer. The spatial separation of the magnetic crystal grains and the high magnetic anisotropy effectively work to realize a high coercive force.

For example, a NiP underlayer is formed on an Al substrate by plating with a thickness of about 10 μm, and a texture is formed by polishing. A CoCr-based alloy containing SiO ₂ is deposited on the textured base surface by sputtering or the like.

There is a strong demand for hard disk drives to reduce power consumption and manufacturing costs. In order to achieve these objects, it is desirable to use a lightweight and inexpensive material. As a substrate material, glass is being used instead of Al. When a glass substrate is used, if the NiP alloy layer is formed directly on the glass substrate, the adhesion of the NiP alloy layer is weak. In order to enhance the adhesive force, a Cr layer is first formed on a glass substrate, and a NiP alloy layer is formed thereon.

[0009]

When the magnetic crystal grains are completely magnetically isolated, the maximum coercive force is theoretically 値 of the anisotropic magnetic field Hk of the magnetic crystal grains. It is known. For example, when a Co ₈₈ Pt ₁₂ alloy is used for the magnetic layer material, the anisotropic magnetic field Hk is about 6000 Oe. Therefore, the coercive force should be up to about 3000 Oe.

At present, the maximum coercive force of a magnetic layer using a Co ₈₈ Pt ₁₂ alloy realized is about 2000 Oe.
Therefore, there is still room for improvement in increasing the coercive force of the magnetic crystal grains.

In order to reduce the power consumption and manufacturing cost of a hard disk drive, it is desirable to use a material that is lighter and cheaper than a glass substrate. There is an organic material as a material satisfying such conditions. For example,
If polycarbonate or amorphous polyolefin can be used as the substrate material, the magnetic recording medium of the hard disk drive can be further reduced in weight and the manufacturing cost can be reduced.

An object of the present invention is to provide a method for manufacturing a magnetic recording medium having a magnetic layer with a further increased coercive force.

It is another object of the present invention to provide a method of manufacturing a magnetic recording medium which is lighter and cheaper than the case where a glass substrate is used.

[0014]

According to one aspect of the present invention, there is provided (a) a step of depositing a nonmagnetic oxide layer on a nonmagnetic organic substrate by sputtering, and (b) the step of depositing the oxide layer. (C) depositing a nickel-phosphorus alloy layer on the adhesion layer by sputtering, and (d) depositing a nickel-phosphorus alloy layer on the adhesion layer. On top, the magnetic layer was set to a gas pressure of 10 mTorr-5.
0.05 nm / sec using an Ar atmosphere of 0 mTorr
c) depositing by sputtering at a deposition rate of 1.5 nm / sec.

The magnetic layer is formed in an argon atmosphere having a gas pressure of 10 mTorr to 50 mTorr, which is significantly higher than the conventional gas pressure, at a thickness of 0.05 nm, which is lower than the conventional deposition rate.
By depositing at a deposition rate of / sec to 1.5 nm / sec by sputtering, the coercive force of the magnetic layer can be increased.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. In addition, although an Example is described about the case where a specific structure and material are used, these do not limit this invention.

FIG. 1 is a sectional view showing a structure of a magnetic recording medium manufactured according to an embodiment of the present invention and a perspective view schematically showing a state of use of the magnetic recording medium.

In FIG. 1A, an organic substrate 1 is formed of, for example, polycarbonate. Instead of polycarbonate, it is also possible to use other organic materials such as amorphous polyolefin. An oxide layer 2 is formed on a surface of an organic substrate 1. The oxide layer 2 is formed of, for example, SiO ₂ . Al instead of SiO ₂
It is also possible to use other oxides such as ₂ O ₃ , TiO ₂ , TaO ₂ , Ta ₂ O ₅ and WO ₂ .

The oxide layer 2 continuously covers the entire surface of the organic substrate 1 and functions to prevent outgassing from the organic substrate 1 during subsequent film deposition. The organic substrate 1 provided with the oxide layer 2 can be considered in the same manner as a glass substrate.

An adhesion layer 3 made of Cr is formed on the surface of the oxide layer 2. NiP on the adhesion layer 3
An alloy base layer 4 is formed. The adhesion layer 3 plays a role in enhancing the adhesion between the oxide layer 2 and the alloy base layer 4.

The NiP alloy underlayer 4 is made of, for example, Ni ₃ P,
It is formed of a NiP alloy such as Ni ₂ P. The NiP alloy base layer 4 forms a base surface having a relatively large surface roughness. The magnetic layer 5 is formed on the underlayer surface. The magnetic layer 5 is, for example, a CoPt-based alloy to which SiO ₂ is added. On the surface of the magnetic layer 5, a protective layer 6 is provided as necessary. With such a configuration, the magnetic disk 7 is formed.

FIG. 1B shows the state of use of the magnetic disk 7. The magnetic disk 7 is rotated, and the magnetic head 8 flies above the magnetic disk 7. The magnetic head 8 generates a magnetic flux to perform writing on the magnetic disk 7, and detects magnetic flux generated by the magnetic disk 7 to read out write information. Although an inductive magnetic head is illustrated, a composite magnetic head in which writing is performed by an inductive magnetic head and reading is performed by a magnetoresistive element can be used. The type of the magnetic head is not limited.

In order to perform the use as shown in FIG. 1B, it is required that the magnetic disk 7 flies the magnetic head 8 stably.

FIG. 2 is a sectional view showing the configuration of a DC / RF magnetron sputtering apparatus that can be used to form a laminated structure on the organic substrate 1 as shown in FIG. The chamber 11 is formed of a metal such as stainless steel or aluminum, and the inside can be evacuated to a vacuum.

The chamber 11 has an Ar gas inlet 1
2 and an exhaust port 13 are provided. Chamber 1
The substrate holder 14 is connected to the upper part of the first. The substrate holder 14 is also formed of metal,
And electrical and mechanical connection. The chamber 11 is grounded.

An opening is provided in a lower part of the chamber 11, and a cathode body 16 is hermetically connected via an insulator 15. Cathode body 16 has a cavity inside,
A magnet 21 is arranged in the cavity. In addition, a flow path is provided inside the cathode body 16 so that a coolant such as cooling water can pass therethrough.

The cathode body 16 is connected to a power supply 18. The power supply 18 has a configuration capable of switching between an RF power supply and a DC power supply. Note that the RF power supply includes a matching box. Further, a shield 24 supported by an insulator 23 is arranged so as to surround the cathode body 16.

A target can be placed on the cathode body 16 and the substrate can be held on the substrate holder 14 to perform sputtering. In the sputtering, an Ar gas is introduced from an Ar gas inlet 12 and a predetermined amount of Ar gas is
By exhausting the gas, the inside of the chamber 11 is maintained in an Ar atmosphere at a predetermined pressure. When DC or RF power is supplied to the cathode body 16, the substrate holder 14, the cathode body 1
Plasma is generated between 6. This plasma is subjected to the action of the magnetic flux generated by the magnet 21 and magnetron sputtering the target. Particles jumping out of the target face upward and accumulate on the substrate.

When Al or glass is used as the substrate, the substrate is heated to about 300 ° C. to perform sputtering. When an organic material is used as the substrate, such heating cannot be performed. For example, polycarbonate is easily deformed and melted by heating at about 130 ° C.

When an organic substrate is used, it is required to perform sputtering without heating the substrate. For example, when depositing a magnetic layer containing a non-magnetic metal or SiO ₂ , if the substrate temperature is low, migration of atoms and molecules in the deposited magnetic layer is expected to decrease. The present inventors examined how the characteristics of the deposited magnetic layer change by changing the sputtering conditions of the magnetic layer.

FIG. 3 is a graph showing the change in coercive force of the magnetic layer when the Ar gas pressure during sputtering is changed. In the configuration shown in FIG. 1A, the magnetic recording medium thus produced has SiO ₂ on the surface of the polycarbonate substrate 1.
Layer 2 was deposited to a thickness of 300 nm, and a Cr adhesion layer was
a Ni ₃ P layer 4 is deposited thereon to a thickness of 30 nm, and a Co ₈₈ Pt ₁₂ —SiO ₂ (5 at%) layer 5 is further deposited thereon.
Is formed to have a thickness of 20 nm. The Ar gas pressure during the formation of the magnetic layer 5 was changed.

As is apparent from the figure, when the Ar gas pressure was increased from a normally used several mTorr to 10 mTorr, the coercive force Hc was greatly improved. When the Ar gas pressure was further increased to 20 mTorr and 30 mTorr, the increasing tendency of the coercive force became remarkably gentle, but the increase of the coercive force continued. Ar gas pressure 30mTorr-50mTorr
In the region, a substantially constant coercive force Hc is shown. In the used sputtering apparatus, 5
It has been difficult to stably use a gas pressure exceeding 0 mTorr.

From the results shown in FIG. 3, it is presumed that it is desirable to set the atmospheric pressure at the time of sputtering to 10 mTorr to 50 mTorr in order to realize a high coercive force.

Generally, when the atmospheric pressure during sputtering is increased, the deposition rate tends to decrease. Then, what kind of change appears in the magnetic characteristics when the deposition rate was intentionally reduced was examined. The prepared sample is basically a magnetic recording medium having a laminated structure shown in FIG. 1A, and the thickness of each layer is 30 nm for an SiO ₂ layer, 15 nm for a Cr layer,
_The 3P layer was 26 nm, and the magnetic layer was 24 nm. The magnetic layer was made of Co ₈₈ Pt ₁₂ : SiO ₂ similarly to the one used in the experiment of FIG.
(5 at%).

The deposition rates of the Ni ₃ P layer 4 and the magnetic layer 5 were changed to various values as shown in Table 1 below.

[0036]

[Table 1]

The SiO ₂ layer 2 was deposited by RF sputtering, the Cr layer 3 and the Ni ₃ P layer 4 were deposited by DC sputtering, and the magnetic layer 5 was deposited by RF sputtering. The Ar pressure during sputtering was kept constant at 30 mTorr. The deposition rate of the Ni ₃ P layer 4 is 0.06 nm
/ Sec to 2.4 nm / sec. Also,
The deposition rate of the magnetic layer 5 ranges from 0.07 nm / sec to 2.2.
nm / sec.

FIG. 4 shows the magnetostatic characteristics of the obtained magnetic layer.
4 is a graph showing as a function of magnetic layer deposition rate.

FIG. 4A shows the dependence of the coercive force on the deposition rate of the magnetic layer. The horizontal axis represents the magnetic layer deposition rate in nm / sec.
The vertical axis indicates the coercive force Hc in units of Oe. As is clear from the figure, the coercive force increases as the deposition rate decreases.

In particular, when the deposition rate was changed from 2.2 nm / sec to 1.5 nm / sec, the coercive force Hc was improved beyond the conventional maximum coercive force of 2000 Oe.
When the deposition rate is lower than 0.6 nm / sec, the increase in coercive force is significantly improved. It is apparent that the coercive force is improved as the deposition rate is reduced.

However, when the deposition rate is reduced, the time required for depositing a magnetic layer having a constant thickness becomes longer. Considering mass productivity, it is not practical to set the deposition rate to a value close to zero.

In order to reduce the deposition rate, the power during sputtering is reduced or the distance between the target and the substrate is increased. The distance between the target and the substrate is related to the size of the chamber and is limited in size. The remaining possibility is a method of reducing the power during sputtering.

To reduce the deposition rate, the power must be reduced. However, if the sputtering is performed with an extremely weak power, the plasma tends to be unstable.
As a result of these factors, the deposition rate is about 0.05 nm / sec.
It is desired to be not less than c. Therefore, the deposition rate at the time of sputtering the magnetic layer is 0.05 nm / sec to 1.
It is desirable to select within the range of 5 nm / sec.

FIG. 4B is a graph showing the deposition rate dependence of t · Br which is the product of the magnetic layer thickness t and the residual magnetic flux density Br. The horizontal axis shows the deposition rate of the magnetic layer in the unit of nm / sec, and the vertical axis shows t · Br in the unit of G μm. The magnetic layer thickness / residual magnetic flux density product t · Br shows an inverse relationship to the coercive force, but keeps a value of 100 Gμm or more even when the deposition rate is 0.05 nm / sec.

FIG. 5 shows the deposition rate dependence of the squareness ratio S of the magnetic hysteresis characteristic and the squareness ratio S ^* of the coercive force of the obtained magnetic layer. FIG. 5A shows the squareness ratio S, and FIG.
(B) shows the coercive force squareness ratio S ^* . It can be seen from both of the characteristics that the squareness ratio achieves a good value of about 0.9 or more regardless of the deposition rate.

FIG. 8 is a graph showing the average diameter of the magnetic crystal grains in the magnetic layer 5 as a function of the magnetic layer deposition rate. When the deposition rate is 1.5 nm / sec or less, the particle size is 11n.
m or less is obtained. Considering the measurement results of the coercive force Hc, it is considered that a coercive force exceeding 2000 Oe can be obtained when the average grain size of the magnetic crystal grains in the magnetic layer is set to 11 nm or less.

In the above experiment, the deposition of the Ni ₃ P layer 4 was also carried out with the Ar gas pressure increased and the deposition rate reduced, but the Ni ₃ P layer 4 was formed under the same conditions as in the prior art. And sputtering of only the magnetic layer 5 is performed at an Ar pressure of 10
mTorr to 50 mTorr, deposition rate 0.05 nm
It has further been confirmed that a high coercive force can be realized by performing the process at / sec to 1.5 nm / sec. Of course, the alloy underlayer 4 can also be sputtered under the same conditions.

The sample used in the above experiment is shown in FIG.
Although an organic substrate having a configuration as shown in FIG. 1A is used, the same effect can be obtained by using the above conditions for the sputtering of the Ni ₃ P layer 4 and the magnetic layer 5 even when another substrate is used. Is expected to be obtained. For example,
Using an Al substrate, a Ni ₃ P layer 4 and a magnetic layer 5
Can be performed under the same conditions as in the experiment described above. Further, a glass substrate is used, and a Cr adhesion layer 3 is formed thereon.
The same effect will be obtained by performing the Ni ₃ P layer 4 and the magnetic layer 5 under the same conditions as in the above experiment.

The present inventors have also studied other conditions. FIG. 6 shows the result of examining the change in Hc with respect to the thickness of the SiO ₂ layer 2. The thickness of the SiO ₂ layer 2 is 0n
m (without SiO ₂ ), 5 nm, 10 nm, 30 nm, 5
It was changed to 0 nm. The thicknesses of the other layers were 20 nm for the Cr adhesion layer, 30 nm for the Ni ₃ P layer, and 20 nm for the magnetic layer. It can be seen that the coercive force Hc is extremely low when the SiO ₂ layer 2 does not exist or when the thickness is 10 nm or less. Therefore, it is desirable that the thickness of the SiO ₂ layer 2 be 10 nm or more.

[0050] The magnetic disk 2 is also required to have the capability of flying the magnetic head. Therefore, the thickness of the SiO ₂ layer 2 is set to 1
0 nm, 50 nm, and 90 nm, and the radial position on the disc was changed to 20 mm, 22 mm, 24 mm, 26 mm,
The flying test of the magnetic head was performed while changing the distance to 28 mm and 30 mm. Table 2 shows the results.

[0051]

[Table 2]

From the results of the magnetic head flying test shown in Table 2, it can be seen that when the thickness of the SiO ₂ layer is as thick as 90 nm, the magnetic head crashes and stable flying is difficult. Therefore, the thickness of the SiO ₂ layer is 10 nm to 50 nm.
It is desirable to select in the range of nm.

The Cr layer 3 is made of SiO_TwoLayer 2 and Ni_ThreeP layer 4
Has the role of promoting adhesion to Therefore, the thickness of the Cr layer
We also examined the effect. The thickness of the Cr layer 3 is 0 nm
(No Cr layer) Changed to 5nm, 10nm, 50nm
And then Ni_ThreeP layer 4 is deposited, and
A test was conducted in which the tape was attached and peeled off. Note that SiO
_TwoThe thickness of the layer 2 is 30 nm,_ThreeThe thickness of the P layer 4 is 3
It was set to 0 nm.

In the peeling test, a test of sticking and peeling a scotch tape of 5 mm × 5 mm was performed on 20 samples per sample, and the number of times peeling occurred was expressed as a percentage.
Table 3 shows the results of the peel test.

[0055]

[Table 3]

As is clear from the results in Table 3, the Cr layer 3
When the thickness is less than 10 nm, there is a high possibility that the film is peeled off, but when the thickness of the Cr layer 3 is 10 nm or more, no peeling occurs. Therefore, the thickness of the Cr layer 3 is 10 n
m or more.

The thickness of the Cr layer 3 is set to 0 nm, 50 nm, 90
nm, and a flying test of the magnetic head was performed. The thickness of the other layers was 10 nm for the SiO ₂ layer, 10 nm for the Ni ₃ P layer, and 20 nm for the magnetic layer. Table 4 shows the results of the magnetic head flying test.

[0058]

[Table 4]

As is clear from the results shown in Table 4, when the thickness of the Cr layer is 90 nm, a crash of the magnetic head occurs at a position where the radial position is near the center. When the thickness of the Cr layer is set to 50 nm, stable floating of the magnetic head can be obtained. Therefore, the thickness of the Cr layer 3 is 10 nm to 5 nm.
It is desirable to select in the range of 0 nm.

FIG. 7 is a graph showing a change in the coercive force Hc of the magnetic layer when the thickness of the Ni ₃ P layer 4 is changed.
The thickness of the SiO ₂ layer 2 is 30 nm, and the thickness of the Cr layer 3 is 20 n.
m, the thickness of the magnetic layer 5 was 20 nm, and the thickness of the Ni ₃ P layer 4 was changed to 5 nm, 10 nm, 30 nm, and 50 nm. With respect to the change in the thickness of the Ni ₃ P layer 4, the coercive force Hc of the magnetic layer 5 changed as shown in FIG. In the drawing, the horizontal axis indicates the thickness of the Ni ₃ P layer in nm, and the vertical axis indicates the coercive force Hc in Oe.

As is apparent from the figure, the Ni ₃ P layer 4 has 5
In the case of nm, the coercive force is extremely low, and by setting it to 10 nm to 50 nm, a stable high coercive force is obtained. Therefore, the thickness of the Ni ₃ P layer 4 is desirably 10 nm or more.

Further, by changing the thickness of the Ni ₃ P layer 4,
A flying test of the magnetic head was performed. The thickness of the Ni ₃ P layer is
The values were changed to 10 nm, 50 nm, and 90 nm. The thicknesses of the other layers were 10 nm for the SiO ₂ layer, 10 nm for the Cr layer, and 20 nm for the magnetic layer. Table 5 shows the results of the test.

[0063]

[Table 5]

As is clear from the results in Table 5, Ni ₃ P
When the thickness of the layer 4 is set to 50 nm or less, a stable flying result is obtained. However, when the thickness of the Ni ₃ P layer is set to 90 nm, the magnetic head crashes on the magnetic disk.
Therefore, the thickness of the Ni ₃ P layer is desirably 50 nm or less.

In consideration of the coercive force and the flying performance of the magnetic head, it is desirable to select the thickness of the Ni ₃ P layer from the range of 10 nm to 50 nm.

A method for manufacturing the magnetic recording medium shown in FIG. 1A based on the above results will be described below.

An SiO ₂ layer 2 is deposited on the surface of an organic substrate 1 such as polycarbonate by sputtering to a thickness of 10 nm to 50 nm. Cr layer 3 having a thickness of 1 on SiO ₂ layer 2
Deposit by 0 to 50 nm sputtering. Cr layer 3
A Ni ₃ P layer 4 is deposited by sputtering to a thickness of 10 to 50 nm. On the Ni ₃ P layer 4, the magnetic layer 5 is Ar
In an atmosphere with a gas pressure of 10 mTorr to 50 mTorr,
Deposition is performed by sputtering at a deposition rate of 0.05 nm / sec to 1.5 nm / sec. The magnetic layer 5 is, for example, a CoPt alloy to which 5 at% of SiO ₂ is added.

Since SiO ₂ and Pt in the magnetic layer 5 do not have a function as a magnetic material, when the content thereof is increased, the magnetic characteristics of the magnetic film 5 are reduced. Therefore, it is desirable that the content of Pt be 40 at% or less and the content of SiO _{2 be} 20 at% or less. Note that addition of other materials besides Pt is not limited. For example, Cr or the like may be added as a nonmagnetic metal. Also,
Ni or the like may be added as a magnetic metal.

Although the present invention has been described with reference to the embodiments, the present invention is not limited to these embodiments. It will be apparent to those skilled in the art that various modifications, improvements, combinations, and the like can be made.

[0070]

As described above, according to the present invention,
A magnetic recording medium having a magnetic layer with a high coercive force is manufactured.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a configuration of a magnetic recording medium manufactured according to an embodiment of the present invention and a perspective view illustrating a use state.

FIG. 2 is a cross-sectional view illustrating a configuration of a sputtering apparatus used in an embodiment of the present invention.

FIG. 3 is a graph showing the results of an experiment in which the Ar gas pressure was changed.

FIG. 4 is a graph showing the results of an experiment in which the deposition rate was changed.

FIG. 5 is a graph showing the results of an experiment in which the deposition rate was changed.

FIG. 6 is a graph showing the results of an experiment in which the thickness of the SiO ₂ layer was changed.

FIG. 7 is a graph showing the results of an experiment in which the thickness of the Ni ₃ P layer was changed.

FIG. 8 is a graph showing a relationship between a deposition rate of the magnetic film and an average particle diameter in the magnetic film.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Organic substrate 2 Oxide layer 3 Cr adhesion layer 4 NiP alloy underlayer 5 Magnetic layer 6 Protective layer 7 Magnetic disk 8 Magnetic head

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Kazumasa Shimoda 4-1-1, Kamiodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa F-term in Fujitsu Limited (Reference) 5D006 BB01 BB07 CA01 CA05 CA06 CB01 DA03 EA03 FA09 5D112 AA02 AA03 AA05 AA11 AA24 BA01 BD02 BD04 BD06 FA04 FB19 5E049 AA04 AA09 BA06 GC04

Claims (10)

[Claims] 1. A step of (a) depositing a nonmagnetic oxide layer on a nonmagnetic organic substrate by sputtering; and (b) depositing a nonmagnetic adhesion layer on the oxide layer by sputtering. (C) depositing a nickel-phosphorous alloy layer on the adhesion layer by sputtering; and (d) depositing a magnetic layer on the nickel-phosphorous alloy layer at a gas pressure of 10 mTorr-50 mTorr of Ar. Using the atmosphere,
Depositing by sputtering at a deposition rate of 0.05 nm / sec-1.5 nm / sec. 2. The method according to claim 1, wherein the step (d) is performed by using an RF magnetron.
2. The method for manufacturing a magnetic recording medium according to claim 1, wherein the method is sputtering. 3. The method according to claim 1, wherein in the step (d), a CoPt alloy to which SiO ₂ is added is sputtered. 4. The method for manufacturing a magnetic recording medium according to claim 3, wherein the CoPt alloy to which SiO ₂ is added contains SiO _{2 of} 20 at% or less and Pt of 40 at% or less. 5. The method according to claim 1, wherein the step (c) is performed at a gas pressure of 10 mTorr.
Using an Ar atmosphere of r-50 mTorr, 0.05 nm
5. The method for manufacturing a magnetic recording medium according to claim 1, wherein the method is performed at a deposition rate of /sec-1.5 nm / sec. 6. The oxide layer has a thickness of 10 nm to 50 n.
m is a continuous SiO ₂ layer without a break.
5. The method for manufacturing a magnetic recording medium according to any one of items 5. 7. The method according to claim 1, wherein the adhesion layer has a thickness of 10 nm to 50 nm.
The method for producing a magnetic recording medium according to any one of claims 1 to 6, wherein the magnetic recording medium is a continuous Cr layer having no discontinuity. 8. The nickel-phosphorus alloy layer has a thickness of 10 nm.
The method for producing a magnetic recording medium according to claim 1, wherein the magnetic recording medium has a thickness of 50 to 50 nm. 9. A step of depositing a nickel-phosphorus alloy layer on a substrate by sputtering, and forming a magnetic layer on the nickel-phosphorus alloy layer at a gas pressure of 10 m.
Using an Ar atmosphere of Torr to 50 mTorr, 0.0
Depositing by sputtering at a deposition rate of 5% nm / sec-1.5 nm / sec. 10. A non-magnetic organic substrate; a non-magnetic oxide layer formed on the organic substrate; a non-magnetic adhesion layer formed on the oxide layer; And a magnetic layer formed on the nickel-phosphorus alloy layer and having a mean grain size of 11 nm or less.