JP3173490B2 - Perpendicular magnetic recording media - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a perpendicular magnetic recording medium used as a high recording density magnetic disk or the like.

[0002]

2. Description of the Related Art In recent years, with the progress of personal computers and workstations, the amount of information to be handled has been increasing year by year, so that a large capacity of a hard disk drive is required. The magnetic disk as the information storage part is required to have a higher areal density. However, in the longitudinal magnetic recording system that is now widely used, in order to achieve high recording density, thermal fluctuation of recording magnetization due to miniaturization of recording bits and high coercive force of the medium that may exceed the recording capacity of the recording head Is a problem. Therefore, a perpendicular magnetic recording system is being studied as a means for solving these problems and greatly improving the areal recording density.

As one of the perpendicular magnetic recording media for realizing this, there is a perpendicular magnetic recording medium comprising a soft magnetic film having a high magnetic permeability and a perpendicular magnetic film having a high perpendicular anisotropy. FIG. 38A shows a configuration diagram of such a perpendicular magnetic recording medium.

The perpendicular magnetic recording medium 20 has a base soft magnetic film 23 and a perpendicular magnetization film 24 formed on a substrate 21 in this order. For example, a NiFe film is used as the underlying soft magnetic film 23, and a CoCr-based alloy film is used as the perpendicular magnetization film 24 (Journal of the Japan Society of Applied Magnetics, Vol. 8, No. 1, No. 1).
984, p17).

Japanese Patent Application Laid-Open No. 6-28652, which is directed to this perpendicular magnetic recording medium, discloses a high magnetic permeability magnetic film, a high magnetic permeability magnetic film, an antiferromagnetic film, an antiferromagnetic film, Barkhausen noise is suppressed during recording / reproducing on a perpendicular magnetic recording medium in which magnetic films are sequentially formed, but the thickness of the antiferromagnetic film between the perpendicular magnetic film and the high-permeability magnetic film is increased during recording / reproducing. It is described that a bias magnetic field imparting film is formed on the surface of the high magnetic permeability magnetic film on the substrate side, because it acts as a loss to lower the reproduction output level.

Japanese Patent Application Laid-Open No. Hei 10-228620, which also targets a perpendicular magnetic recording medium, discloses an improvement in noise characteristics and envelope characteristics during recording and reproduction, and recording and reproduction characteristics at a high recording density. It describes that a first soft magnetic film having a coercive force of 1-100 Oe, a second soft magnetic film made of a sendust film, and a perpendicular magnetization film are formed on a substrate in this order.

The present inventors have filed a Japanese Patent Application No. 09-349810, filed before the application, and filed a perpendicular magnetic recording medium in which a chromium film having good surface smoothness is inserted between a substrate and an underlying soft magnetic film Sendust. Was invented and disclosed. This perpendicular magnetic recording medium is referred to as a conventional medium of the prior invention, and FIG.
It is shown in (B). This perpendicular magnetic recording medium 30 has a Cr crystal orientation control film 32, an FeSiAl base soft magnetic film 33, and a perpendicular magnetic film 34 made of a CoCr-based alloy formed on a substrate 31 in this order.

[0008]

However, FIG. 38 (B)
In the conventional medium of the prior invention shown in (1), the following problem has occurred.

A first problem is that medium noise during recording and reproduction is large. The reason is that, since the crystal grain size of the Cr film is large, the sendust film and the Co
The crystal grain size of the Cr-based magnetic film also increases. That was a source of noise.

The second problem is that the output has a poor dependence on the recording density. The first reason is that since the crystal orientation of Cr having a bcc structure is poor, the (110) orientation of a sendust film having a bcc structure is deteriorated, and the hc film formed thereon is deteriorated.
This is because the c-axis orientation of the CoCr alloy film having the p structure is deteriorated. The second reason is that the thickness of the initial layer is large.

It is an object of the present invention to provide a perpendicular magnetic recording medium in which medium noise during recording and reproduction is reduced and output is more dependent on recording density.

[0012]

The perpendicular magnetic recording medium according to the present invention is characterized in that a NiAl film is provided between the substrate and the underlying soft magnetic film. NiA with fine and uniform crystal grain size
By inserting the 1 film, the c-axis orientation of the perpendicular magnetization film can be improved, and the crystallite can be made finer and more uniform. Further, it is possible to reduce noise and improve the recording density dependency of the output.

In the above perpendicular magnetic recording medium according to the present invention, the (NiaAl1-a) 100
It is characterized by having a NiAl alloy film of -bcd-eTibMocVdWe (at.%). However, the range is 0.20 ≦ a ≦ 0.80.
Also 0 ≦ b ≦ 40, 0 ≦ c ≦ 40, 0 ≦ d ≦ 40, 0 ≦ a ≦ 40, and 0.
The range is 1 ≦ b + c + d + e ≦ 40. By inserting a NiAl alloy film having a fine and uniform crystal grain size, the c-axis orientation of the perpendicular magnetization film can be improved, and the crystallite can be made fine and uniform. Further, it is possible to reduce noise and improve the recording density dependency of the output.

Further, in the perpendicular magnetic recording medium according to the present invention, the underlying soft magnetic film is made of FeSiAl film or FeSiAl film.
Films, FeNi films and FeCo films.
NiAl or NiAl with fine and uniform crystal grain size
By inserting the alloy film, the c-axis orientation of the perpendicular magnetization film can be improved, and the crystallite can be made finer and more uniform. Further, it is possible to reduce noise and improve the recording density dependency of the output.

Further, in the above perpendicular magnetic recording medium according to the present invention, the underlying soft magnetic film is made of FeSiAl, Fe, FeN.
The film is characterized by being a film in which one or more elements of Ti, Zr, Nb, Hf, Ta or Y are added to i or FeCo. By inserting a NiAl or NiAl alloy film having a fine and uniform crystal grain size, the c-axis orientation of the perpendicular magnetization film can be improved, and the crystallite can be made fine and uniform. Further, it is possible to reduce noise and improve the recording density dependency of the output.

In the above perpendicular magnetic recording medium according to the present invention, the soft magnetic underlayer may be made of FeSiAl, Fe, FeN.
The film is characterized by being a film in which one or more elements of N, Si, B, C, Al or P are added to i or FeCo. NiAl or N with fine and uniform crystal grain size
By inserting the iAl alloy film, the c-axis orientation of the perpendicular magnetization film can be improved, and the crystallite can be made finer and uniform. Further, it is possible to reduce noise and improve the recording density dependency of the output.

Further, in the above perpendicular magnetic recording medium according to the present invention, the underlying soft magnetic film is made of FeSiAl, Fe, FeN.
i or FeCo, one or more of Ti, Zr, Nb, Hf, Ta or Y, and N, Si, B,
It is a film to which one or more elements of C, Al or P are added.

Further, according to the present invention, in a perpendicular magnetic recording medium having a substrate, an underlying soft magnetic film and a perpendicular magnetic film in this order, the orientation of the crystal of the perpendicular magnetic film and the orientation of the perpendicular magnetic film are located between the substrate and the underlying soft magnetic film. It has a crystal orientation and particle size control film for controlling the diameter of each particle of the perpendicular magnetization film to be uniform, and the crystal orientation and particle size control film is a NiAl film or a NiAlTi film.
There is a feature.

In the above perpendicular magnetic recording medium, the crystal orientation and particle size control film may be a NiAl film or a NiA film.
It is characterized by being an lTi film.

In the perpendicular magnetic recording medium according to the present invention, by inserting a NiAl or NiAl alloy film having a fine and uniform crystal grain size, the c-axis orientation of the perpendicular magnetization film can be improved, and the crystallite can be made fine and uniform. Is possible. Further, it is possible to reduce noise and improve the recording density dependency of the output.

[0021]

FIG. 1 is a schematic sectional view showing an embodiment of a perpendicular magnetic recording medium according to the present invention.

The perpendicular magnetic recording medium according to the present embodiment
NiAl or NiA with fine and uniform crystal grain size
a crystal orientation and particle size control layer 12 made of a 1 alloy film;
FeSiAl film, Fe film, FeNi film, FeCo film,
An underlying soft magnetic film 13 made of a film to which one or more elements of Ti, Zr, Nb, Hf, Ta or Y and one or more elements of N, Si, B, C, Al or P are added; And the perpendicular magnetization film 14 of CoCr-based alloy
It is formed above.

By inserting a NiAl or NiAl alloy film having a fine and uniform crystal grain size between the substrate and the soft magnetic film, the c-axis orientation of the perpendicular magnetization film can be improved, and the crystallite can be made finer and more uniform. Can be realized. As a result, it is possible to reduce the medium noise and improve the recording density dependency of the output.

An embodiment of the present invention will be described below. Hereinafter, the medium of FIG. 38B in Japanese Patent Application No. 09-349810 will be referred to as “conventional medium” or “prior application medium”, and the perpendicular magnetic recording medium according to the present invention will be referred to as “present invention medium”.

[0025]

Embodiments of the present invention will be described below in detail.

[Example 1] As Example 1 of the present invention, a 6-inch diameter 50Ni-50Al (at.
%) Using a target, a 10 nm-thick NiAl film for the crystal orientation and particle size control layer 12 was formed. The film formation conditions are as follows: an initial vacuum degree of 5 × 10 ⁻⁷ mTorr and an input power of 0.
5 kW and an argon gas pressure of 5 mTorr.

Next, a 6 inch diameter 74 is formed on the NiAl film.
Using an Fe-16Si-10Al (at.%) Target, the FeSiAl of the underlying soft magnetic film 13 was formed under the same film forming conditions.
A film was formed to a thickness of 500 nm. Using a 6 inch diameter 78Co-19Cr-3Ta (at.%) Target thereon, the CoCrTa of the perpendicular magnetization film 14 was formed under the same film forming conditions.
Films were each formed to a thickness of 50 nm. The medium manufactured in this manner is referred to as medium A1 of the present invention. Under the same film forming conditions, a Cr film was formed to a thickness of 10 nm using a Cr (3N) target instead of the NiAl target, and a medium in which FeSiAl and CoCrTa films were formed under the same conditions as the medium A1 of the present invention was used. B1.

In order to examine the c-axis orientation of the perpendicular magnetization films of the medium A1 of the present invention and the conventional medium B1, the half width of the rocking curve of the hcp (002) peak was determined using X-ray diffraction. By forming a NiAl film instead of the Cr film, the half width (Δθ50) of the rocking curve of the hcp (002) peak of the CoCrTa film is changed from 6.1 degrees to 4.
This was reduced to 9 degrees, and the c-axis orientation of the perpendicular magnetization film was improved.

The crystal grain size and dispersion of the perpendicular magnetization films of the conventional medium B1 and the medium A1 of the present invention were examined using a cross-sectional transmission electron microscope (TEM). NiAl instead of Cr film
By forming the film, the average crystal grain size of the CoCrTa film is reduced from 28 nm to 21 nm, the standard deviation of the crystal grain size is reduced from 10 nm to 7 nm, and the crystallite of the perpendicular magnetization film is made finer and more uniform. You can see that they are connected.

The conventional medium B1 and the medium A1 of the present invention are designated by ID / M
An experiment of recording and reproduction was performed with an R composite head. Here, the recording track width is 4 μm, the reproduction track width is 3 μm, the recording gap length is 0.4 μm, and the reproduction gap length is 0.32 μm.
It is. The evaluations were a recording current of 10 mAop and a sense current of 12
mA, a peripheral speed of 12.7 m / s, a flying height of 45 nm, and a noise band band of 45 MHz.

FIG. 2 shows the recording density dependence of the medium noise. From this, it can be seen that the medium A1 of the present invention has smaller medium noise at all recording densities than the conventional medium B1, and has extremely excellent noise characteristics. In other words, it is considered that replacing the Cr film with the NiAl film improved the c-axis orientation of the perpendicular magnetization film and made the crystallites finer and more uniform, leading to lower noise.

FIG. 3 shows the recording density dependency of the reproduced output signal. Compared with the conventional medium B1, the medium A1 of the present invention has a slower output attenuation with an increase in recording density, can secure a high output up to a high recording density, and can easily realize a high recording density. This is presumably because the improvement in the c-axis orientation of the perpendicular magnetization film led to the improvement in the recording density dependency of the output.

As shown in FIG. 2 and FIG.
1 is the medium S at all recording densities compared to the conventional medium B1.
/ N is good, and is excellent as a magnetic disk medium compatible with high recording density. That is, the use of the medium A1 of the present invention facilitates realization of a high recording density.

Further, under the same manufacturing conditions as the medium A1 of the present invention,
i amount is 15, 20, 35, 65, 80 and 85 at.
The media manufactured using the NiAl target of% are media A2, A3, A4, A5, A6, and A7, respectively. For the conventional medium B1 and the mediums A1 to A7, the half-width Δθ50 of the rocking curve, the average crystal grain size, the standard deviation of the crystal grain size, the noise voltage, and the frequency D50 which is half the solitary wave output voltage are measured. did. FIG. 4 shows the results.

FIG. 4 shows that the media A3, A4, A5, and A6 of the present invention have better characteristics than the conventional media B1.
This is because the Ni content of the NiAl film is moderate.
Since the crystallinity of the NiAl film is good and the crystal grain size is small, it is considered that the c-axis orientation of the perpendicular magnetization film is improved, and further, the crystallite is made finer and more uniform.

The comparative media A2 and A7 are inferior in these characteristics to the conventional medium B1. The reason is Ni
Since the Ni content of the Al film is not appropriate, the crystallinity of the NiAl film is poor and the crystal grain size is large, so that the c-axis orientation of the perpendicular magnetization film is deteriorated, and the crystal grain size is increased. Is non-uniform.

As described above, in the perpendicular magnetic recording medium, the layer between the substrate and the underlying soft magnetic film is made of Cr at 20 at.
% Or more, 80 at. %, The improvement of the c-axis orientation of the perpendicular magnetization film, the miniaturization and uniformity of crystallites, the reduction of noise, and the improvement of the recording density dependency of output can be realized. is there.

[Embodiment 2] As Embodiment 2 of the present invention, a 45-inch 45Ni-45Al-10Ti (a) having a diameter of 6 inches was formed on a 3.5-inch Al substrate as the substrate 11 by a sputtering method.
t. %) Using a target, a NiAlTi film of the crystal orientation and particle diameter control layer 12 was formed to a thickness of 20 nm. The film formation conditions were as follows: the initial vacuum degree was 6 × 10 ⁻⁷ mTorr, the input power was 0.7 kW, and the argon gas pressure was 6 mTorr.

Next, using a 6 inch diameter 74Fe-16Si-10Al (at.%) Target on the NiAlTi film, the FeSi of the underlying soft magnetic film 13 was formed under the same film forming conditions.
An Al film was formed to a thickness of 500 nm. Using a 6-inch diameter 78Co-20Cr-2Ta (at.%) Target thereon, the CoCr of the perpendicular magnetization film 14 was formed under the same film forming conditions.
A 100 nm thick Ta film was formed.

The medium thus manufactured is referred to as a medium C1 of the present invention. Under the same film forming conditions, a Cr (3N) target is used instead of a NiAlTi target to form a C film.
A medium on which an r film is formed to a thickness of 20 nm and a FeSiAl and CoCrTa film is formed under the same conditions as the medium C1 of the present invention is referred to as a conventional medium D1.

In order to examine the c-axis orientation of the perpendicular magnetization film of the conventional medium D1 and the medium C1 of the present invention, the half width of the rocking curve of the hcp (002) peak was obtained by using X-ray diffraction as in Example 1. Was. As a result, the hcp of the CoCrTa film
(002) The half width of the rocking curve of the peak is 4.4.
It can be seen that the temperature is reduced from 3.6 degrees to 3.6 degrees, which leads to improvement of the c-axis orientation of the perpendicular magnetization film.

The crystal grain size and dispersion of the perpendicular magnetic film of the conventional medium D1 and the medium C1 of the present invention were examined by using a cross-sectional TEM.
By forming a NiAlTi film instead of a Cr film, the crystal grain size of the CoCrTa film is changed from 27 nm to 21 nm.
It can be seen that the dispersion of the crystal grain size is reduced from 12 nm to 8 nm, which leads to the miniaturization and uniformization of the crystallite of the perpendicular magnetization film.

As in the first embodiment, the Cr film is formed of NiAlTi
It is considered that by replacing the film, the c-axis orientation of the perpendicular magnetization film was improved, and the crystallites were made finer and more uniform.

The medium D1 of the prior art and the medium C1 of the present invention are referred to as ID / M
An experiment of recording and reproduction was performed with an R composite head. The head specifications and measurement conditions are the same as in the first embodiment.

FIG. 5 shows the recording density dependence of the medium noise. It can be seen that the medium C1 of the present invention has smaller medium noise at all recording densities than the conventional medium D1, and has extremely excellent noise characteristics. That is, by replacing the Cr film with a NiAlTi film, the c-axis orientation of the perpendicular magnetization film is improved,
In addition, it is considered that the crystallites were miniaturized and made uniform, which led to a reduction in noise.

FIG. 6 shows the recording density dependence of the reproduced output signal. Compared with the conventional medium D1, the medium C1 of the present invention has a slower output attenuation with an increase in recording density, can secure a high output up to a high recording density, and can easily realize a high recording density. It is considered that the improvement in the c-axis orientation of the perpendicular magnetization film has led to an improvement in the recording density dependency of the output.

The medium C1 of the present invention has a good medium S / N at all recording densities as compared with the conventional medium D1, and is excellent as a magnetic disk medium corresponding to a high recording density. That is, the use of the medium C1 of the present invention facilitates realization of a high recording density.

Further, under the same manufacturing conditions as the medium C1 of the present invention,
35Ni-35Al-30Ti, 30Ni-3 instead of 5Ni-45Al-10Ti (at.%) Target
0Al-40Ti and 28Ni-28Al-44Ti
(At.%) The media manufactured using the targets are referred to as media C2, C3, and C4, respectively. With respect to the conventional medium D1 and the mediums C1 to C4, the half width Δθ50 of the rocking curve, the average crystal grain size, the standard deviation of the crystal grain size, the noise voltage, and the frequency D50 which is half the solitary wave output voltage were measured. FIG. 7 shows the result.

The mediums C2 and C3 are superior in these characteristics to the conventional medium D1. The reason is that Ti to NiAl
Since the addition rate of Ni is appropriate, the crystallinity of the NiAl alloy film is good and the crystal grain size is small, so that the c-axis orientation of the perpendicular magnetization film of the CoCrTa layer is improved, and the crystal grain size is refined and uniform. It is to make it.

The medium C4 is inferior in these characteristics to the conventional medium D1. The reason for this is that since the addition ratio of Ti to NiAl is too large, the crystallinity of the NiAl alloy film deteriorates and the c-axis orientation of the perpendicular magnetization film of the CoCrTa layer deteriorates.

As described above, in the perpendicular magnetic recording medium, the layer between the substrate and the underlying soft magnetic film was changed from a Cr film to a Ni0.50A
10.50) By using a 100-a Tia (at.%) film and a NiAl alloy film satisfying a ≦ 40, the c-axis orientation of the perpendicular magnetization film can be improved, the crystallite can be made finer and uniform, and the lowering can be achieved. It is possible to realize noise reduction and to improve the recording density dependency of the output.

Embodiment 3 As Embodiment 3 of the present invention,
6 inch diameter (Ni0.67Al0.33) 100-aMoa on a 3.5 inch Al substrate by sputtering.
(At.%) The NiAlMo film was
0 nm was formed. The film formation conditions are as follows: initial vacuum degree 6 × 10 ⁻⁷ mT
At orr, the input power was set to 0.7 kw and the argon gas pressure was set to 6 mTorr. Next, a Fe film was formed to a thickness of 500 nm on the NiAlMo film under the same film forming conditions using a 6 inch diameter Fe (4N) target. A 6 inch diameter 76Co-18Cr-1Ta-5Pt (at.
%) Using a target and CoCrTa under the same film forming conditions.
Pt films were each formed to a thickness of 50 nm. Where a = 10,
The media designated 31 and 40 were the media C5 of the present invention, respectively.
The medium where C6 and C7 are set and a = 43 is set as the comparative medium C8. Under the same film forming conditions as those of the media C5 to C8, Ni
A conventional medium D2 is a medium in which a Cr film is formed to a thickness of 20 nm using a Cr (3N) target instead of the AlMo target, and Fe and CoCrTaPt films are formed under the same conditions as the mediums C5 to C8.

Conventional medium D2, present medium C5, C6, C
For Sample No. 7 and Comparative Medium C8, the half width Δθ50 of the rocking curve, the average crystal grain size, the standard deviation of the crystal grain size, the noise voltage, and the frequency D50 which is half of the solitary wave output voltage were measured. FIG. 8 shows the result. These measuring methods are the same as in Example 1.

FIG. 8 shows that the mediums C5, C6 and C7 are superior in these characteristics to the conventional medium D2. The reason is N
Since the addition rate of Mo to iAl is moderate, the crystallinity of the NiAl alloy film is good and the crystal grain size is small, so that Co
This is because the c-axis orientation of the perpendicular magnetization film of the CrTaPt layer is improved, and the crystal grain size is reduced and made uniform.

The medium C8 is inferior in these characteristics to the conventional medium D2. The reason for this is that the crystallinity of the NiAl alloy film is deteriorated due to the excessive addition ratio of Mo to NiAl, and the c-axis orientation of the perpendicular magnetization film of the CoCrTaPt layer is deteriorated.

As described above, in the perpendicular magnetic recording medium, the layer between the substrate and the underlying soft magnetic film was changed from the Cr film to (Ni0.67Al0.33) 10
By using a 0-aMoa (at.%) Film and a NiAl alloy film satisfying a ≦ 40, the c-axis orientation of the perpendicular magnetization film is improved, the crystallite is made finer and uniform, the noise is reduced, and the output is reduced. Of the recording density can be improved.

Example 4 As Example 4 of the present invention,
A 6-inch diameter (Ni0.33Al0.67) 100-a (Ti0.5) was formed on a 2.5-inch glass substrate by sputtering.
0V0.50) a (at.%) Target and NiAlT
An iV film was formed to a thickness of 10 nm. The film formation conditions were 5 × initial vacuum.
At 10 ^-7 mTorr, the input power was 0.5 kW and the argon gas pressure was 4 mTorr. Next, using a 6-inch diameter 80Fe-20Co (at.%) Target on the NiAlTiV film, the FeCo film was
0 nm was formed. 6 inch diameter 78Co on them
Using a -18Cr-4Ta (at.%) Target,
Under the same film forming conditions, a CoCrTa film was formed to a thickness of 100 nm. Here, the media with a = 10, 30, and 40 are the mediums C9, C10, and C11 of the present invention, respectively, and the medium with a = 46 is the comparative medium C12. Further, under the same film forming conditions as those of the media C9 to C12, NiAlTi
A conventional medium D3 is a medium in which a Cr film is formed to a thickness of 10 nm using a Cr (3N) target instead of the V target, and FeCo and CoCrTa films are formed under the same conditions as the mediums C9 to C12.

With respect to the conventional medium D3, the mediums C9, C10 and C11 of the present invention, and the comparative medium C12, the half width Δθ50 of the rocking curve, the average crystal grain size, the standard deviation of the crystal grain size, the noise voltage, and the solitary wave output voltage were calculated. 1 /
Was measured. FIG. 9 shows the result. These measuring methods are the same as in Example 1.

FIG. 9 shows that the media C9, C10 and C
No. 11 has these characteristics better than the conventional medium D3. The reason is that the addition ratio of Ti and V to NiAl is moderate, so that the crystallinity of the NiAl alloy film is good and the crystal grain size is small, so that the c-axis orientation of the perpendicular magnetization film of the CoCrTa layer is improved, In addition, the crystal grain size is made finer and uniform.

The medium C12 is inferior in these characteristics to the conventional medium D3. The reason for this is that since the addition ratio of Ti and V to NiAl is too large, the crystallinity of the NiAl alloy film deteriorates and the c-axis orientation of the perpendicular magnetization film of the CoCrTa layer deteriorates.

As described above, in the perpendicular magnetic recording medium, the layer between the substrate and the underlying soft magnetic film is changed from the Cr film to the (Ni0.33Al
0.67) 100-a (Ti0.50V0.50) a (at.%)
By using a NiAl alloy film that satisfies a ≦ 40, it is possible to improve the c-axis orientation of the perpendicular magnetization film, to make crystallites finer and more uniform, to reduce noise, and to improve the recording density dependence of output. It is feasible.

Embodiment 5 As Embodiment 5 of the present invention,
A 15-nm NiAlMoW film is formed on a 2.5-inch glass substrate using a 6-inch diameter (Ni0.50Al0.50) 100-a (Mo0.80W0.10) a (at.%) Target by sputtering. did. The film formation conditions are as follows: an initial vacuum degree of 4 × 10 ⁻⁷ mTorr, an input power of 0.4 kW, and an argon gas pressure of 5 mTorr.
And Next, a 90-inch diameter of 6 inches is formed on the NiAlMoW film.
Using a Fe-10Ni (at.%) Target, a 500 nm FeNi film was formed under the same film forming conditions. 6 inch diameter 78Co-16Cr-3Ta-3P on them
Using the t (at.%) target, C
An oCrTaPt film was formed to a thickness of 60 nm. Here, the media with a = 10, 30, and 40 are the present invention media C13, C14, and C15, respectively, and the media with a = 45 are the comparative media C16. Media C13 to C13
Under the same film forming conditions as in Example 16, a Cr (3N) target was used instead of the NiAlMoW target to form a Cr film
under the same conditions as for the media C13 to C16.
The medium on which the Ni and CoCrTaPt films are formed is referred to as a conventional medium D4.

Conventional medium D4, present invention media C13, C14
With respect to C15 and C15 and the comparative medium C16, the half width Δθ50 of the rocking curve, the average crystal grain size, the standard deviation of the crystal grain size, the noise voltage, and the frequency D50 which is half the solitary wave output voltage were measured. The result is shown in FIG. These measuring methods are the same as in Example 1.

As shown in FIG. 10, the media C13, C14 and C15 of the present invention are superior in these characteristics to the conventional media D4. This is because the addition ratio of Mo and W to NiAl is moderate, the crystallinity of the NiAl alloy film is good, and the crystal grain size is small, so that the c-axis orientation of the perpendicular magnetization film of the CoCrTaPt layer is improved, In addition, the crystal grain size is made finer and uniform.

The medium C16 is inferior in these characteristics to the conventional medium D4. The reason for this is that since the addition ratio of Mo and W to NiAl is too large, the crystallinity of the NiAl alloy film deteriorates and the c-axis orientation of the perpendicular magnetization film of the CoCrTaPt layer deteriorates. Thus, in the perpendicular magnetic recording medium, the layer between the substrate and the underlying soft magnetic film
(Ni0.50Al0.50) 100-a (Mo0.80W0.10) a (at.%) Film and a NiAl alloy film in which a ≦ 40 improves the c-axis orientation of the perpendicular magnetization film , Miniaturization and uniformization of crystallites,
It is possible to reduce noise and improve the recording density dependency of the output.

Embodiment 6 As Embodiment 6 of the present invention,
A 15-nm NiAl film was formed on a 2.5-inch glass substrate by a sputtering method using a 6-inch diameter 60Ni-40Al (at.%) Target. The film forming conditions are as follows: an initial vacuum degree of 6 × 10 ⁻⁷ mTorr, and a power of 0.6 k.
w, the argon gas pressure was 4 mTorr. Next, NiAl
6-inch diameter (Fe0.85Co0.15) 100-xZrx (at.%) On the membrane
Using a target, a FeCoZr film was formed to a thickness of 400 nm under the same film forming conditions. 76 inches of 6 inch diameter on them
Using a Co-17Cr-2Ta-5Pt (at.%) Target, a CoCrTaPt film was formed under the same film forming conditions by 60%.
nm. Where x = 0.1, 10, 20
And 30 are the media E1 and E of the present invention, respectively.
2, E3 and E4, and media with x = 35 and 40 are comparative media E5 and E6. Further, under the same film forming conditions as those of the media E1 to E6, a Cr film was formed to a thickness of 15 nm using a Cr (3N) target instead of the 60Ni-40Al target, and (Fe0.85Co0.15) 100-xZrx (at.%). ) A FeCoZr film is formed using a target, and then a CoC
An rTaPt film was formed. In the medium using this Cr film, x
= 0.1, 10, 20, 30, 35, and 40 were replaced with conventional media F1, F2, F3, F4, F5, and F
6 is assumed.

For the conventional media F1 to F6, the media E1 to E4 of the present invention, and the comparative media E5 and E6, the half width Δθ50 of the rocking curve, the average crystal grain size, the standard deviation of the crystal grain size, the noise voltage, and the solitary wave output voltage Was measured. Figure 1 shows the results.
1, shown in FIG. These measuring methods are the same as in Example 1.

From FIG. 11 and FIG. 12, the mediums E1 and E of the present invention are shown.
2, E3 and E4 are conventional media F1, F2,
These properties are superior to F3 and F4. This is because the addition rate of Zr to FeCo is moderate, the crystallinity of the FeCo alloy film on the NiAl film with good crystallinity is good, and the crystal grain size is small. Therefore, the c-axis of the perpendicular magnetization film of the CoCrTa layer is small. This is because the orientation is improved, and the crystal grain size is reduced and uniformized.

Also, the comparative media E5 and E6 are inferior in these characteristics to the conventional media F5 and F6, respectively. This is because the addition rate of Zr to FeCo is too large, and the crystallinity of the FeCo alloy film is deteriorated, and CoCrT
This is because the c-axis orientation of the perpendicular magnetization film of the a-layer is deteriorated.

As described above, as the underlying soft magnetic film of the perpendicular magnetic recording medium, x is 0.1 or more and 30 or less (Fe0.85Co0.15)
When forming a FeCoZr film using a 100-xZrx (at.%) Target, 60Ni-4
A medium in which a NiAl film is formed using a 0Al (at.%) Target has an improved c-axis orientation of a perpendicular magnetization film and a finer and more uniform crystallite than a medium in which a Cr film has been formed. It can be seen that noise reduction and output density dependence on recording density are good.

Seventh Embodiment As a seventh embodiment of the present invention, a medium in which a NiAl alloy film is formed between a substrate and a base soft magnetic film in the same manner as in the sixth embodiment, and a Cr (3N) target under the same conditions For the medium on which Cr was formed by using the method, the amount of the non-magnetic additive element of the underlayer soft magnetic film was changed, and the half width of the rocking curve Δθ50, the average crystal grain size, the standard deviation of the crystal grain size, the noise voltage, and the isolation A frequency D50 that is half the wave output voltage was measured. 13 to 1 show the results.
FIG. These measuring methods are the same as in Example 1.
The composition of the perpendicular magnetization film, the composition of the soft magnetic underlayer, NiAl
FIG. 19 shows the composition of the alloy, the thickness of each layer, the initial vacuum degree, the input power, and the argon gas pressure.

13 to 18 that (Fe0.74Si0.16Al
0.10) 100-xTix (at.%), (Fe0.80Ni0.20) 100-x (Nb0.50Hf
0.50) x (at.%) And Fe100-x (Ti0.40Ta0.30Y0.30) x (a
t.%) Non-magnetic element addition rate x (at.
%) Is 0.1 to 30, the medium in which the NiAl alloy film is formed between the substrate and the underlying soft magnetic film is
It can be seen that, compared to a medium on which a Cr film is formed, the perpendicular magnetization film has better c-axis orientation, finer and more uniform crystallites, lower noise, and higher output density dependency on recording density.

The reason for this is that Ti, Zr,
Since the addition rates of Nb, Hf, Ta and Y are moderate,
Since the underlying soft magnetic film on the NiAl alloy film having good crystallinity has good crystallinity and a small crystal grain size, the c-axis orientation of the perpendicular magnetization film is improved, and the crystal grain size becomes fine and uniform. That's why.

In a medium in which x (at.%) Is 30 or more, Ti, Zr, Nb, Hf, T
This is because if the addition ratios of a and Y are too large, the crystallinity of the underlying soft magnetic film deteriorates, and the c-axis orientation of the perpendicular magnetization film deteriorates.

[Eighth Embodiment] As an eighth embodiment of the present invention, as in the sixth embodiment, a medium in which a NiAl alloy film is formed between a substrate and a base soft magnetic film, and a Cr (3N) target under the same conditions For the medium on which Cr was formed by using the method, the amount of the non-magnetic additive element of the underlayer soft magnetic film was changed, and the half width of the rocking curve Δθ50, the average crystal grain size, the standard deviation of the crystal grain size, the noise voltage, and the isolation A frequency D50 that is half the wave output voltage was measured. The results are shown in FIGS.
It is shown in FIG. These measuring methods are the same as in Example 1.
The composition of the perpendicular magnetization film, the composition of the soft magnetic underlayer, NiAl
FIG. 28 shows the composition of the alloy, the thickness of each layer, the initial vacuum degree, the input power, and the argon gas pressure.

FIGS. 20 to 27 show that Fe100-xNx (at.
%), (Fe0.80Co0.20) 100-xSix (at.%), (Fe0.70Ni0.30) 100
-x (B0.60Al0.40) x (at.%) and Fe100-x (N0.30C0.50P0.
20) x (at.%) Addition rate of non-magnetic element of the underlying soft magnetic film x (a
t. %) Is 0.1 or more and 30 or less, the medium in which the NiAl alloy film is formed between the substrate and the underlying soft magnetic film has a higher c of the perpendicular magnetization film than the medium in which the Cr film is formed. It can be seen that it is good in terms of improvement of the axial orientation, miniaturization and uniformity of crystallites, reduction of noise, and dependence of output on recording density.

The reason for this is that N, Si,
Since the addition rates of B, C, Al and P are moderate, the crystallinity of the underlying soft magnetic film on the NiAl alloy film with good crystallinity is also good, and the crystal grain size is small. This is because the crystallinity is improved and the crystal grain size is reduced and uniformized.

In the medium where x (at.%) Is 30 or more, the addition ratio of N, Si, B, C, Al and P to the underlying soft magnetic film is too large, and This is because the crystallinity deteriorates and the c-axis orientation of the perpendicular magnetization film deteriorates.

Embodiment 9 As Embodiment 9 of the present invention,
An NiAl alloy film was formed to a thickness of 15 nm on a 2.5-inch glass substrate by sputtering using a 6-inch diameter 51Ni-46Al-3Ti (at.%) Target.
The film forming conditions were as follows: the initial vacuum degree was 6 × 10 ⁻⁷ mTorr, the input power was 0.5 kW, and the argon gas pressure was 5 mTorr.
Next, a 6-inch diameter (Fe0.90Co0.10) was formed on the NiAl alloy film.
Using a 100-x (TayC1-y) x (at.%) Target, a 500 nm-thick FeCoTaC film was formed under the same film forming conditions. On top of them is a 6 inch diameter 79Co-18Cr-3Ta (a
t. %) Using a target and CoCr under the same film forming conditions
A Ta film was formed to a thickness of 60 nm. Here, the Ta addition rate with respect to the C addition rate is defined as y = 0.001, 0.35, 0.6.
5 and 0.999, and for each y, x =
The half width Δθ50 of the rocking curve of the medium set to 0.1, 10, 20, and 30, the average crystal grain size, the standard deviation of the crystal grain size, the noise voltage, and a half of the solitary wave output voltage
Was measured. The results are shown in FIGS. Also, under the same manufacturing conditions, 51Ni-46Al
Cr (3%) instead of -3Ti (at.%) Target
N) A Cr film was formed to a thickness of 15 nm using a target, a FeCoTaC film was formed under the same conditions, and then a CoCrT film was formed.
FIG. 2 also shows the measurement results of the film formed with the a film.
9, shown in FIG.

According to FIGS. 29 and 30, y = 0.001,
In all of 0.35, 0.65, and 0.999, the addition rate x (at.%) Of the nonmagnetic element of the (Fe0.90Co0.10) 100-x (TayC1-y) x underlying soft magnetic film is 0. In a medium having a thickness of 1 or more and 30 or less, a medium in which a NiAl alloy film is formed between a substrate and a base soft magnetic film has a higher c-axis orientation of a perpendicular magnetization film than a medium in which a Cr film is formed. It can be seen that this method is good in terms of improvement, miniaturization and uniformity of crystallites, low noise, and dependence of output on recording density.

The reason is that, since the addition rates of Ta and C to the underlying soft magnetic film are moderate, the underlying soft magnetic film on the NiAl alloy film having good crystallinity has good crystallinity and a small crystal grain size. This is because the c-axis orientation of the perpendicular magnetization film is improved, and the crystal grain size is reduced and uniformized.

Also, y = 0.001, 0.35, 0.6
5 and 0.999, x (at.%)
Is 30 or more, the Ta and C addition rates of the underlying soft magnetic film are too large, so that the crystallinity of the underlying soft magnetic film deteriorates and the c-axis orientation of the perpendicular magnetization film deteriorates. is there.

[Embodiment 10] As Embodiment 10 of the present invention, as in Embodiment 6, NiA was placed between the substrate and the underlying soft magnetic film.
Cr (3N) under the same conditions as the medium on which the
For the medium on which Cr was deposited using the target, the amount of the nonmagnetic additive element in the underlying soft magnetic film was changed, and the half width Δθ50 of the rocking curve, the average crystal grain size, the standard deviation of the crystal grain size, the noise voltage, and 1/2 of solitary wave output voltage
Was measured. The results are shown in FIGS. These measuring methods are the same as in Example 1. Also, the composition of the perpendicular magnetization film, the composition of the underlying soft magnetic film, Ni
FIG. 37 shows the composition of the Al alloy, the thickness of each layer, the initial vacuum degree, the input power, and the argon gas pressure.

According to FIGS. 31 to 36, (Fe0.75Co0.25)
100-x (Zr0.40C0.60) x (at.%), Fe100-x (Nb0.30Y0.10Al0.
40P0.20) x (at.%) And (Fe0.74Si0.16Al0.10) 100-x (T
i0.25Hf0.20Si0.15B0.40) x (at.%) In a medium in which the non-magnetic element addition rate x (at.%) of the underlying soft magnetic film is 0.1 or more and 30 or less, the substrate and the underlying soft magnetic The medium in which the NiAl alloy film is formed between the films has a higher c-axis orientation of the perpendicular magnetization film, finer and more uniform crystallites, lower noise, than the medium in which the Cr film is formed. It is clear that the output is dependent on the recording density.

The reason for this is that Ti, Zr,
Since the addition rates of Nb, Hf, Ta, Y, N, Si, B, C, Al and P are moderate, the crystallinity of the underlying soft magnetic film on the NiAl alloy film with good crystallinity is good, and the crystal grain size is large. Is also small, so that the c-axis orientation of the perpendicular magnetization film is improved, and the crystal grain size is refined and uniform.

In a medium in which x (at.%) Is 30 or more, Ti, Zr, Nb, Hf, T
This is because, because the addition rates of a, Y, N, Si, B, C, Al and P are too large, the crystallinity of the underlying soft magnetic film deteriorates and the c-axis orientation of the perpendicular magnetization film deteriorates.

[0087]

According to the perpendicular magnetic recording medium of the present invention, Ni is 20 at. % At least 80 at. % Or less of the NiAl film between the substrate and the underlying soft magnetic film, the c-axis orientation of the perpendicular magnetization film was improved, and the crystallites were refined and uniformized. It is considered something. Therefore, it is possible to reduce medium noise and improve the recording density dependency of the reproduction output voltage.

According to the perpendicular magnetic recording medium of the present invention, the NiAl alloy film of (NiaAl1-a) 100-bcd-eTibMocVdWe (at.%) Is provided between the substrate and the underlying soft magnetic film. In addition, it is considered that the c-axis orientation of the perpendicular magnetization film was improved, and the crystallites were made finer and more uniform. Therefore, it is possible to reduce medium noise and improve the recording density dependency of the reproduction output voltage. However, 0.
The range is 20 ≦ a ≦ 0.80. 0 ≦ b ≦ 40,
0 ≦ c ≦ 40, 0 ≦ d ≦ 40, 0 ≦ a ≦ 40, and 0.
The range is 1 ≦ b + c + d + e ≦ 40.

The underlying soft magnetic film according to the present invention is made of FeS
In a perpendicular magnetic recording medium that is an iAl film, an Fe film, a FeNi film, or an FeCo film, the c-axis orientation of the perpendicular magnetization film is improved because the NiAl alloy film is provided between the substrate and the underlying soft magnetic film. Further, it is considered that the crystallites were refined and uniformized. Therefore, it is possible to reduce medium noise and improve the recording density dependency of the reproduction output voltage.

The soft magnetic underlayer according to the present invention is made of FeS
Ti, Zr, iAl, Fe, FeNi or FeCo
At least one element of Nb, Hf, Ta or Y is 0.1 at. % Or more, 30 at. % Of the perpendicular magnetic recording medium, which is a film to which the NiAl alloy film is added between the substrate and the underlying soft magnetic film.
It is considered that the c-axis orientation of the perpendicular magnetization film was improved, and the crystallites were made finer and more uniform. Therefore, it is possible to reduce medium noise and improve the recording density dependency of the reproduction output voltage.

The soft magnetic underlayer according to the present invention is made of FeS
N, Si, iAl, Fe, FeNi or FeCo
B, C, Al or P, at least one element is 0.1 at. % Or more, 30 at. % Of the perpendicular magnetic recording medium, a NiAl alloy film is interposed between the substrate and the underlying soft magnetic film, so that the c-axis orientation of the perpendicular magnetization film is improved and the crystallite is refined. It is considered that the uniformization was achieved. Therefore, it is possible to reduce medium noise and improve the recording density dependency of the reproduction output voltage.

The soft magnetic underlayer according to the present invention is made of FeS
Ti, Zr, iAl, Fe, FeNi or FeCo
At least one element of Nb, Hf, Ta or Y is 0.1 at. % Or more, 30 at. % Or less, and at least one element of N, Si, B, C, Al or P is added at 0.1 at. % Or more, 30a
t. % Of the perpendicular magnetic recording medium, a NiAl alloy film is interposed between the substrate and the underlying soft magnetic film, so that the c-axis orientation of the perpendicular magnetization film is improved and the crystallite is refined. It is considered that the uniformization was achieved. Therefore, it is possible to reduce medium noise and improve the recording density dependency of the reproduction output voltage.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing an embodiment of a perpendicular magnetic recording medium according to the present invention.

FIG. 2 is a graph showing the recording density dependence of medium noise in Example 1 of the present invention.

FIG. 3 is a graph showing the recording density dependency of a reproduction output signal in Example 1 of the present invention.

FIG. 4 is a table showing the layer thickness of each layer, medium preparation conditions, and measurement results in Example 1 of the present invention.

FIG. 5 is a graph showing the recording density dependence of medium noise in Example 2 of the present invention.

FIG. 6 is a graph showing the recording density dependency of a reproduced output signal in Example 2 of the present invention.

FIG. 7 is a table showing the layer thickness of each layer, medium manufacturing conditions, and measurement results in Example 2 of the present invention.

FIG. 8 is a table showing the layer thickness of each layer, medium manufacturing conditions, and measurement results in Example 3 of the present invention.

FIG. 9 is a table showing the layer thickness of each layer, medium preparation conditions, and measurement results in Example 4 of the present invention.

FIG. 10 is a table showing the layer thickness of each layer, medium preparation conditions, and measurement results in Example 5 of the present invention.

FIG. 11 is a graph showing various measurement results in Example 6 of the present invention.

FIG. 12 is a graph showing various measurement results in Example 6 of the present invention.

FIG. 13 is a graph showing various measurement results in Example 7 of the present invention.

FIG. 14 is a graph showing various measurement results in Example 7 of the present invention.

FIG. 15 is a graph showing various measurement results in Example 7 of the present invention.

FIG. 16 is a graph showing various measurement results in Example 7 of the present invention.

FIG. 17 is a graph showing various measurement results in Example 7 of the present invention.

FIG. 18 is a graph showing various measurement results in Example 7 of the present invention.

FIG. 19 is a table showing the layer thickness of each layer and medium manufacturing conditions in Example 7 of the present invention.

FIG. 20 is a graph showing various measurement results in Example 8 of the present invention.

FIG. 21 is a graph showing various measurement results in Example 8 of the present invention.

FIG. 22 is a graph showing various measurement results in Example 8 of the present invention.

FIG. 23 is a graph showing various measurement results in Example 8 of the present invention.

FIG. 24 is a graph showing various measurement results in Example 8 of the present invention.

FIG. 25 is a graph showing various measurement results in Example 8 of the present invention.

FIG. 26 is a graph showing various measurement results in Example 8 of the present invention.

FIG. 27 is a graph showing various measurement results in Example 8 of the present invention.

FIG. 28 is a table showing the layer thickness of each layer and medium manufacturing conditions in Example 8 of the present invention.

FIG. 29 is a graph showing various measurement results in Example 9 of the present invention.

FIG. 30 is a graph showing various measurement results in Example 9 of the present invention.

FIG. 31 is a graph showing various measurement results in Example 10 of the present invention.

FIG. 32 is a graph showing various measurement results in Example 10 of the present invention.

FIG. 33 is a graph showing various measurement results in Example 10 of the present invention.

FIG. 34 is a graph showing various measurement results in Example 10 of the present invention.

FIG. 35 is a graph showing various measurement results in Example 10 of the present invention.

FIG. 36 is a graph showing various measurement results in Example 10 of the present invention.

FIG. 37 is a diagram illustrating a layer thickness of each layer according to the tenth embodiment of the present invention.
4 is a table showing conditions for producing a medium.

FIG. 38 is a schematic sectional view showing a conventional perpendicular magnetic recording medium.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Perpendicular magnetic recording medium 11 Glass substrate 12 Crystal orientation control film 13 Underlayer soft magnetic film 14 Perpendicular magnetization film 20 Perpendicular magnetic recording medium 21 Glass substrate 23 Underlayer soft magnetic film 24 Perpendicular magnetization film 30 Perpendicular magnetic recording medium 31 Glass substrate 32 Crystal orientation Control film 33 Underlying soft magnetic film 34 Perpendicular magnetization film

Claims (7)

(57) [Claims] 1. A perpendicular magnetic recording medium having an underlayer soft magnetic film and a perpendicular magnetization film, wherein Ni is 20 at. % Or more, 80 at. % Of a perpendicular magnetic recording medium having a NiAl film in the range of not more than 0.1%. 2. A perpendicular magnetic recording medium having an underlying soft magnetic film and a perpendicular magnetic film, wherein (NiaAl1-a) 100-bcd-eTibMocVdWe (at.%) Is provided between the substrate and the underlying soft magnetic film.
having an iAl alloy film, a is in the range of 0.20 ≦ a ≦ 0.80, and 0 ≦ b ≦ 40, 0 ≦ c ≦ 40, 0 ≦ d ≦ 40, 0 ≦ a ≦ 40,
A perpendicular magnetic recording medium, wherein 0.1 ≦ b + c + d + e ≦ 40. 3. The perpendicular magnetic recording medium according to claim 1, wherein the soft magnetic film is a FeSiAl film, an Fe film, a FeNi film, or an FeCo film. 4. The perpendicular magnetic recording medium according to claim 1, wherein the soft magnetic film is made of FeSiAl, Fe, FeNi, or FeCo;
A perpendicular magnetic recording medium characterized by being a film containing at least one element selected from the group consisting of Zr, Nb, Hf, Ta and Y in an amount of 0.1 at.% Or more and 30 at.% Or less. 5. The perpendicular magnetic recording medium according to claim 1, wherein the soft magnetic film is formed of FeSiAl, Fe, FeNi, or FeCo.
A perpendicular magnetic recording medium comprising a film containing at least one element of i, B, C, Al or P added in an amount of 0.1 at.% or more and 30 at.% or less. 6. The perpendicular magnetic recording medium according to claim 1, wherein the soft magnetic film is made of FeSiAl, Fe, FeNi, or FeCo.
r, Nb, Hf, Ta or Y, at least one element is added in an amount of 0.1 at.% or more and 30 at.% or less, and N, Si,
Of B, C, Al or P, at least one element is added in an amount of 0.1 at.% Or more and 30 at.% Or less, and Ti, Zr, N
A perpendicular magnetic recording medium characterized in that the total amount of b, Hf, Ta, Y, N, Si, B, C, Al and P is 0.2 at.% or more and 30 at.% or less. 7. A perpendicular magnetic recording medium having a substrate, an underlying soft magnetic film, and a perpendicular magnetic film in this order, wherein the direction of the crystal of the perpendicular magnetic film and the orientation of the perpendicular magnetic film are located between the substrate and the underlying soft magnetic film. A crystal orientation and particle diameter control film for controlling the diameter of each particle to be uniform, wherein the crystal orientation and particle diameter control film is a NiAl film or Ni
A perpendicular magnetic recording medium characterized by being an AlTi film .