JPH0896358A - Production of magnetic recording medium - Google Patents

Abstract

PURPOSE: To efficiently remove dust in the state of continuing operation and to form a high-quality magnetic recording medium at a high yield with good productivity by blowing desired gaseous flow to a tray for mounting substrates moving from a film forming device, thereby subjecting this tray to a dustproofing treatment. CONSTITUTION: The tray 1A of the substrate holder 1 mounting a disk-shaped substrate 2 in a substrate mounting chamber 1 is supplied to a sputtering chamber 13, where a protective film of carbon hydride is formed by vapor deposition on the magnetic layer of the substrate 2. The holder 1 unloaded from a conveyor in an unloading chamber 15 is passed through a conveyor 16 and a return line 17 to a dustproofing device 20, where ultrasonic vibrating gaseous flow is blown to the tray 1A and the tray is subjected to the dustproofing treatment. The tray 1A from which the substrates are removed in a substrate detaching chamber is recirculated. As a result, the dust on the tray 1A is efficiently removed in the state of continuing the operation and the film forming error is prevented. The high-quality magnetic recording medium is thus efficiently formed at a high yield with good productivity.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a magnetic recording medium. More specifically, the present invention relates to an improvement in a method for manufacturing a magnetic recording medium by mounting a substrate on a tray that circulates in a film forming apparatus and forming a film.

[0002]

2. Description of the Related Art A magnetic recording medium such as a magnetic disk has a magnetic thin film layer (hereinafter referred to as "magnetic layer") made of metal or alloy on a substrate.
Called. Is deposited by a plating method, a vacuum vapor deposition method, a sputtering method, or the like.

With respect to the magnetic recording medium, the abrasion resistance is sufficient to withstand physical contact with the magnetic head during its use, and the corrosion resistance is sufficient to withstand the magnetic layer in a corrosive environment such as water vapor. In order to satisfy such required characteristics, a protective layer is formed on the magnetic layer formed on the substrate.

Conventionally, as the protective layer, a carbonaceous film which is generally considered to have excellent abrasion resistance to a magnetic head has been used. The carbonaceous protective film is used in an atmosphere of a rare gas such as argon, Using graphite or amorphous carbon as a target, it is deposited on the magnetic layer by an ordinary sputtering method.

However, in the magnetic recording medium having the carbonaceous protective film formed on the magnetic layer as described above, sufficient abrasion resistance cannot be obtained in actual use, and therefore the purpose is to improve the abrasion resistance. When forming a carbonaceous protective film by a sputtering method, it has been attempted to form a hydrogenated carbon protective film by making hydrogen gas coexist in a rare gas such as argon.

[0006]

In order to industrially form a magnetic layer and a hydrogenated carbon protective film on a substrate, generally,
Using a pass-through type film forming apparatus, the disk-shaped substrate is mounted on a tray and sequentially transferred by a transfer device. This tray is circulated in the film forming apparatus and repeatedly used. In such a film forming method, as the number of times of film formation increases, fine powder of hydrogenated carbon formed at the time of carbon sputter film formation adheres and deposits on the tray of the transfer device. Then, the tray is transferred to the desorption chamber of the magnetic recording medium via the return system of the film forming device in a state where the fine powder of hydrogenated carbon is adhered, and after the magnetic recording medium is demounted, it is transferred to the substrate mounting chamber again. The substrate is mounted and transferred to the film forming chamber again to perform film formation.In this film forming chamber, when the pressure is reduced to a vacuum, fine powder such as hydrogenated carbon that has adhered to the tray is released from the tray. Then, it soars and pulls, and then adheres to the substrate surface.

When a film is formed with the fine powder of hydrogenated carbon adhered to the substrate, the portion where the fine powder adheres becomes a defect (error) in the obtained magnetic recording medium. For this reason, when the tray in which the fine powder of hydrogenated carbon adheres and the adhered amount increases every time the film is formed, the defects (errors) of the magnetic recording medium increase with the passage of time. .

Therefore, in the conventional method, when the error of the magnetic recording medium increases, it is necessary to periodically remove the carrier such as a tray, especially the fine powder of hydrogenated carbon deposited on the tray. .

However, in order to remove the fine powder of hydrogenated carbon, it is necessary to replace the used tray with a spare tray which has been cleaned by removing the hydrogenated carbon in advance. Since this spare tray requires an operation such as vacuum drying in the film forming apparatus before use, the sputtering of the disk must be temporarily stopped,
There is a problem that the operation is complicated and productivity is reduced due to the stop of the operation.

Further, since the spare tray is very expensive, the quantity to be held is inevitably limited, and when the amount of the fine particles of hydrogenated carbon adhering to the tray increases, a disk with an increased error is suppressed. The tray was not replaced in time, and the product yield was poor.

The present invention solves the above-mentioned conventional problems and provides a magnetic recording medium capable of reducing the occurrence of errors due to the fine powder of hydrogenated carbon adhering to the tray while the film forming apparatus is continuously operated. It is intended to provide a manufacturing method.

[0012]

According to a first aspect of the present invention, there is provided a method of manufacturing a magnetic recording medium, wherein a tray for mounting a substrate is circulated in a film forming apparatus, a substrate is mounted on the tray, and then the film is formed. In a method of manufacturing a magnetic recording medium, in which a film is introduced by introducing it into a film forming chamber of the apparatus, and then the substrate subjected to the film forming process is taken out from the film forming apparatus, a tray which has been moved from the film forming apparatus It is characterized in that a dust removal process is performed by spraying a gas flow vibrated by sound waves.

A method for manufacturing a magnetic recording medium according to a second aspect is the method according to the first aspect, wherein a magnetic layer is formed on the substrate in the film forming chamber, and then a protective layer made of hydrogenated carbon is formed to cover the magnetic layer. Is formed.

According to a third aspect of the present invention, there is provided a method of manufacturing a magnetic recording medium according to the first or second aspect, wherein the film forming apparatus is a carrier type in-line type sputtering apparatus.

The present invention will be described in detail below by exemplifying a method for producing a magnetic recording medium by forming a magnetic layer and a protective layer made of hydrogenated carbon on a substrate.

As the substrate of the magnetic recording medium in the present invention, a usual disc-shaped non-magnetic substrate made of aluminum, aluminum alloy, glass or the like is used. Usually, these non-magnetic substrates are processed to have a predetermined thickness, and after the surface is mirror-finished, a non-magnetic metal such as Ni-P alloy or N is used.
Approximately 5 to about 5% by electroless plating of i-Cu-P alloy
It is used after forming a film with a film thickness of 20 μm to form a surface layer. The surface layer thus formed on the substrate is subjected to texturing as required to form fine grooves or irregularities with high precision to obtain a surface processed layer having a specific surface roughness. By this texturing, adsorption between the magnetic head and the magnetic recording medium can be prevented, CSS characteristics can be improved, and magnetic anisotropy can be improved.

Further, after forming an underlayer on this surface-treated layer, a magnetic layer is deposited. The underlayer is usually formed by a sputtering method, for example, by forming a chromium underlayer having a film thickness of about 50 to 2000 Å.

The magnetic layer formed on this underlayer is usually Co--Cr, Co--Ni, Co--Cr--X,
A magnetic thin film layer of a Co-based alloy represented by Co-Ni-X, Co-W-X or the like is suitable. Here, as X, Li, Si, Ca, Ti, V, Cr, Ni, As, Y,
Zr, Nb, Mo, Ru, Rh, Ag, Sb, Hf, T
a, W, Re, Os, Ir, Pt, Au, La, Ce,
One or more elements selected from the group consisting of Pr, Nd, Pm, Sm and Eu can be mentioned.

The metallic magnetic layer made of such a Co-based alloy is usually deposited on the underlayer of the substrate by means such as sputtering. As the film thickness of this metal magnetic layer,
Usually, it is in the range of 50 to 600Å.

Next, a hydrogenated carbon protective film is formed on the magnetic layer thus formed by sputtering.

The hydrogenated carbon film is not particularly limited as long as it is a film containing hydrogen and carbon,
For example, it is formed by sputtering using carbon as a target in a plasma containing a rare gas and a hydrogen gas. As the target used here, carbon in the form of diamond, graphite or amorphous is used.

As the rare gas, argon, helium, neon, xenon, radon, krypton and the like can be mentioned. Of these, argon is particularly preferably used. The content of hydrogen gas in a sputtering atmosphere containing a rare gas such as argon gas and hydrogen gas is usually 2 to 2.
It is 0% by volume, preferably 5 to 10% by volume.

As the sputtering method, a direct current magnetron sputtering method is usually adopted, but a high frequency magnetron sputtering method can also be used.

The pressure in the chamber during sputtering is usually 0.5 to 20 mTorr, preferably 1 to 1
The substrate temperature is usually 300 ° C. or lower, and preferably in the range of normal temperature to 250 ° C. The distance between the substrate and the target, the sputtering time, the input power, etc. are appropriately determined according to the film thickness of the hydrogenated carbon protective film to be formed.

The thickness of the hydrogenated carbon protective film is usually 50 to 1000Å, preferably 100 to 600Å.

An embodiment of the film forming method of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a schematic configuration diagram showing an embodiment of an in-line type sputtering apparatus which is preferably used for forming each constituent layer in carrying out the method for manufacturing a magnetic recording medium of the present invention, and FIG. 1 is a perspective view showing an ultrasonic vibration gas blow type dust remover provided in the return passage of the sputtering apparatus shown in FIG. 1, and FIG. 3 is a sectional view taken along line III-III in FIG.

First, the substrate holder 1 is moved to the substrate mounting chamber 11 by the transfer device, and a predetermined number of disc-shaped substrates 2 are attached to the tray 1A of the substrate holder 1.
Next, the substrate holder 1 is transferred to the loading chamber 12 and is depressurized to a predetermined pressure and heated to a predetermined temperature.

Next, the substrate holder 1 is transferred to the first area 13A of the sputtering chamber 13, and the substrate 2 mounted on the tray of the substrate holder 1 is subjected to the underlayer target surface 3 of Cr or the like and the magnetic property of the Co-based alloy or the like. While passing through the layer target surface 4, an underlayer of Cr or the like and a magnetic layer of Co-based alloy or the like are formed on the surface of the substrate (textured surface-treated layer) by sputtering under a rare gas atmosphere under the above-mentioned predetermined conditions. Deposition is formed.

Next, the substrate holder 1 is provided with the slit 14
And is transported to the second region 13B of the sputtering chamber 13. Hydrogen gas from the pipe 6 flows into the second region 13B.
Argon gas is introduced at a predetermined ratio from the pipe 7, and the inside is made into a predetermined mixed gas atmosphere. In the second region 13B, a hydrogenated carbon protective film is deposited on the magnetic layer of the disk-shaped substrate 2 on the substrate holder 1 by sputtering while the substrate holder 1 passes through the carbon protective layer target surface 5. To be done.

Next, the unloading chamber chamber 1
The substrate holder 1 is moved to 5 and returned to room temperature and atmospheric pressure.
After that, the substrate 2 is transferred to the substrate loading / unloading chamber 18, and the substrate 2 is removed from the tray 1A of the substrate holder 1. After that, the substrate holder 1 is returned to the substrate mounting chamber 11 via the conveyor 19 by the transfer device. Then, the substrate is attached to the tray 1A of the substrate holder 1 again, and is sequentially transported by the transport device in the normal route, and is repeatedly used repeatedly. In this embodiment, the dust removing device 20 is provided in the return passage 17. Further, in the present invention, the film forming apparatus means an apparatus including a film forming process from the loading chamber chamber 12 to the unloading chamber chamber 15.

As the number of times of film formation increases due to cyclic use, as described above, the hydrogenated carbon fine powder formed during the carbon sputtering film formation adheres and deposits on the tray 1A of the substrate holder 1 and the like. Conventionally, this fine powder is
Circulating the substrate holder and loading chamber chamber 12
When it is put in a vacuum chamber and evacuated, it peels off from the tray or the like and rises up as dust and adheres to the surface of the disk substrate to cause an error. Furthermore, since the tray is recycled, the error occurrence rate increases because the amount of hydrogenated carbon fine powder adhering to the tray increases over time.

In this embodiment, the ultrasonic vibration gas blow type dust remover 20 provided in the return passage 17 blows off the fine powder of hydrogenated carbon adhering to the surface of the tray to reduce the error during film formation on the substrate. Let

FIG. 2 is a perspective view showing the structure of the dust removing device 20 provided in the return passage 17, and FIG.
A cross section of a portion along the line III-III is shown. However, the cover 21B of the one gas injector 20B is omitted in FIG. Further, FIG. 3 is a cross-sectional view showing a state where the tray 1A is passing through the gas injector 20B.

The dust removing system using this dust removing device will be described below.

In the present embodiment, the dust removing device 20 includes a gas injector 20A for removing dust on the front side surface of the tray 1A in FIG. 2 and a gas injector 20B for removing dust on the back side surface of the tray 1A in FIG. Be prepared. The tray 1A of the substrate holder 1 is provided between the injector main body 21A of the gas injector 20A and the cover 22A and the injector main body 22A of the gas injector 20B and the cover 2 by a transfer device (not shown).
The tray 1A and the tray 2A are sequentially run in an upright posture in which the plate surface is vertical, and thus both surfaces of the tray 1A are subjected to dust removal processing.

Next, regarding the structure of the gas injector 20B,
This will be described with reference to FIG.

The injector main body 21B of the gas injector 20B is a vertically long box-like body, and the tray passage surface 23B thereof has a gas outlet 24B and a suction inlet 25B which extend vertically.
And are installed side by side. The gas outlet 24B is the gas outlet pipe 2
6B, and the suction port 25B is connected to the gas suction pipe 27B. The gas outlet pipe 26B and the suction pipe 27B
Together with the pump 28, the filter 29, the slit-structured head 30, and the circulation pipe 31 constitute a circulation system passage. An ultrasonic oscillator 32 is attached to the head 30.

According to this gas injector 20B, the pump 2
The gas sucked from the suction port 25B by 8 is removed from the suction pipe 27B by the filter 29 of the circulation pipe 31, and then ultrasonic vibration is applied by the ultrasonic oscillator 32 in the head 30. Then, the oscillating gas flow is blown onto the tray 1A via the gas outlet pipe 26B and the gas outlet 24B. As a result, fine particulate dust such as hydrogenated carbon adhered to or deposited on the surface of the tray 1A is blown off. The gas containing the soaring dust is sucked through the suction port 25B and the suction pipe 27B as described above. After dust removal, ultrasonic vibration is applied and the gas is again jetted toward the tray 1A. In this way, the tray 1A that has been subjected to the dust removal treatment by blowing the ultrasonic vibration gas flow is sent to the next substrate desorption chamber 18.

The cover 22B is provided to prevent the dust rising from the tray 1A from being scattered around by the gas flow blown onto the tray 1A. Also,
Reference numeral 40 is a static elimination bar for blowing ionized air to the tray 1A side to remove static electricity and facilitate blowing off dust by a gas flow.

The gas injector 20A is also the gas injector 20B.
It has the same configuration as. 26A is a gas outlet pipe, 27
A is a suction pipe.

In the present invention, the frequency of ultrasonic vibration applied to the gas used for spraying is generally 5 to 1
The frequency is preferably set to 00 kHz, particularly 10 to 50 kHz. In addition, the blowing speed of the ultrasonically vibrated gas is generally 10 m / sec or more, especially 30 m / sec.
It is preferably not less than sec, especially in the range of 50 to 1000 m / sec. Further, it is desirable that the distance between the tray surface and the gas outlet be as short as possible.

The gas used for spraying may be a dry gas having a moisture content as low as possible, and the gas species is not particularly limited, but air is preferred in terms of work safety and cost.

The dust removal by the dust remover may be carried out only when the amount of the fine powder of hydrogenated carbon on the tray becomes large, or may be carried out always on the tray returned to the return system. This dust removing process is not limited to before the substrate is removed from the tray, and may be performed after the removal.

According to such a method, the substrate film formation is continued without exchanging the tray, without stopping the film formation operation, and without releasing the decompression in the film formation apparatus. It is possible to reduce part errors.

[0046]

According to the present invention, it causes an error in the film forming section,
Dust such as fine powder of hydrogenated carbon adhered on the tray can be easily removed while the operation is continued. Moreover, since dust removal is performed by the ultrasonic vibration gas flow, it can be performed extremely efficiently.

[0047]

EXAMPLES The present invention will be described in more detail with reference to specific examples.

Example 1 Using the in-line type sputtering apparatus shown in FIG.
A textured disk-shaped substrate (aluminum substrate) is mounted on the substrate holder 1 and conveyed to the sputtering chamber 13 to sequentially form a Cr underlayer, a Co-based magnetic layer and a hydrogenated carbon film to form a magnetic recording medium. Manufactured.

The film forming conditions for the hydrogenated carbon film are film forming pressure 4
The tray 1 returned to the return passage 17 with mTorr and hydrogen / argon mixing ratio = 1/10 (volume ratio).
Both sides of A were dust-removed by the dust-removing device 20 shown in FIG.

The gas blowing speed of the gas injectors 20A and 20B is 200 m / sec, and the ultrasonic vibration frequency is 18 k.
Was set to Hz.

As a result, when the number of errors at the beginning of operation is 1, the error increase rate is 2 as shown in No. 1 of FIG.
Even at 0 hours of operation, it was slightly within 1.5 times.

On the other hand, when the dust remover was stopped and the trays were circulated and used without performing any dust removing treatment on the trays,
The number of errors shows an increasing tendency as shown in No. 2 of Fig. 4,
The number of errors increased about three times after 20 hours.

From the above results, it is clear that according to the present invention, a magnetic disk with few errors can be manufactured with high productivity.

[0054]

As described above in detail, according to the method of manufacturing a magnetic recording medium of the present invention, the tray for mounting the substrate is circulated in the film forming apparatus, and after mounting the substrate on the tray,
In the method of manufacturing a magnetic recording medium, wherein the substrate is introduced into a film forming chamber of the film forming apparatus to form a film, and then the film-formed substrate is taken out of the film forming apparatus. Fine particle dust such as hydrogenated carbon fine powder that causes an error can be removed easily and efficiently without changing the tray without changing the tray, resulting in a high quality magnetic recording medium with few errors. It can be manufactured efficiently with high yield and high productivity.

According to the manufacturing method of the magnetic recording medium of the second aspect, it is possible to efficiently prevent the error in the film forming portion due to the fine powder of hydrogenated carbon.

According to the method of manufacturing a magnetic recording medium of claim 3, the carrier type in-line sputtering apparatus is used.
A magnetic recording medium can be manufactured with high productivity.

[0057]

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing an example of an in-line type sputtering apparatus suitable for carrying out the method for manufacturing a magnetic recording medium of the present invention.

FIG. 2 is a perspective view showing a dust removing device provided in the sputtering device shown in FIG.

FIG. 3 is a cross-sectional view showing details of a gas injector.

FIG. 4 is a graph showing a transition of an error increase rate in Example 1, No. 1 is an example of the present invention, and No. 2 is a comparative example.

[Explanation of symbols]

 1 Substrate Holder 1A Tray 2 Disc Substrate 3 Underlayer Target Surface 4 Magnetic Layer Target Surface 5 Protective Layer Target Surface 11 Substrate Mounting Room 12 Loading Chamber Room 13 Sputter Room 13A First Area 13B Second Area 15 Unloading Chamber Room 17 Return Passage 18 Substrate desorption chamber 20 Dust remover 20A, 20B Gas injector 21A, 21B Injector body 22A, 22B Cover 24B Gas outlet 25B Gas inlet 26A, 26B Gas outlet 27A, 27B Gas inlet 28 28 Pump 29 Filter 30 Head 32 Ultrasonic oscillator 40 Static elimination bar

Claims (3)

[Claims] 1. A substrate mounting tray is circulated in a film forming apparatus, a substrate is mounted on the tray, and then introduced into a film forming chamber of the film forming apparatus to form a film, and then a film is formed. In a method of manufacturing a magnetic recording medium in which a treated substrate is taken out of the film forming apparatus, dust removal processing is performed by spraying a gas flow vibrated by ultrasonic waves onto a tray that has moved from the film forming apparatus. And a method for manufacturing a magnetic recording medium. 2. The magnetic recording method according to claim 1, wherein in the film forming chamber, a magnetic layer is formed on a substrate, and then a protective layer made of hydrogenated carbon is formed to cover the magnetic layer. Medium manufacturing method. 3. The method for manufacturing a magnetic recording medium according to claim 1, wherein the film forming apparatus is a transport type in-line type sputtering apparatus.