JPH0863747A - Production of magnetic recording medium - Google Patents

Abstract

PURPOSE: To lessen the generation of errors by the fine powder of the hydrogenated carbon sticking to trays in the state of continuing the operation of a film forming device by subjecting incoming trays after film formation in the film forming device to a dustproof treatment. CONSTITUTION: A substrate holder 1 is transferred by a transporting device into a substrate device chamber 11 and the prescribed number of sheets of disk-shaped substrates 2 are mounted at the trays of this substrate holder 1. Next, this substrate holder 1 is transported into a loading chamber 12 in the film forming device, is subjected to film formation by a sputtering chamber 13 and an unloading chamber 15 and is transported through a conveyor 16, a return route 17 and a dustproof device 20 in this return route 17 into a substrate attaching and detaching chamber 18, where the substrates 2 are removed from the trays of the substrate holder 1. As a result, the fine granular dust, such as fine powder of the hydrogenated carbon, which is the cause for the errors in the film forming parts sticking to the trays is efficiently removed by the dustproof device 20 in the state of continuing the operation. The productivity of the high-quality magnetic recording media is thus improved.

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 magnetic recording medium desorption chamber via the return system of the film forming apparatus in a state where the fine powder of hydrogenated carbon is adhered, and after the magnetic recording medium is desorbed, it is transferred again to the substrate mounting chamber. The substrate is mounted and transferred to the film forming chamber again for film formation.When the pressure in the film forming chamber is reduced to a vacuum, the fine powder of hydrogenated carbon adhering to the tray is released from the tray. Soar up,
It is pulled and 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, in the tray moved from the film forming apparatus, It is characterized by performing dust removal processing.

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.

A method of manufacturing a magnetic recording medium according to a fourth aspect is the method according to any one of the first to third aspects,
It is characterized in that the tray is subjected to a gas blow process to remove dust.

The present invention will be described in detail below by exemplifying a method of manufacturing 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 base layer of the substrate by means of sputtering or the like. 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 in the range of 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. It is a figure which shows the dust remover provided in the return system path of the sputtering apparatus shown 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 of the substrate holder 1. Next, the substrate holder 1 is loaded into the loading chamber chamber 1
It is conveyed to 2, and is decompressed 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 such as Cr and the magnetic property such as Co alloy. 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 a 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 attaching / detaching chamber 18, and the substrate 2 is removed from the tray 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 of the substrate holder 1 again, and is sequentially transported by the transport device in the forward route, and repeatedly used. 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 carbon sputter film formation adheres and deposits on the tray of the substrate holder 1 or the like. Conventionally, when this fine powder circulates around the substrate holder and is put into the loading chamber chamber 12 and evacuated, it is peeled off from the tray or the like and rises to dust, and adheres to the surface of the disc substrate to cause an error. Generate. 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 the present embodiment, the gas blow type dust removing device 20 provided in the return passage 17 blows away the fine powder of hydrogenated carbon adhering to the surface of the tray to reduce errors during film formation on the substrate.

FIG. 2 is a block diagram of the dust removing device 20 provided in the return passage 17, and shows a cross section of a portion along the line II-II in FIG. The dust removal system using this dust removal device will be described below.

The tray 1A of the substrate holder 1 is moved in the vertically long chamber 21 having a rectangular cross section by the transfer device 22 in an upright posture with the plate surface vertical. Air nozzles 23 are vertically arranged in multiple stages on both side surfaces of the chamber 21 so that air can be blown to both side surfaces of the tray 1A. Exhaust ducts 24A and 24B are connected to the upper and lower surfaces of the chamber 21, respectively.
The air after being blown onto A can be discharged.

A substrate (not shown in FIG. 2) is held on the tray 1A, and a nozzle 23 is provided for the tray 1A.
By blowing air from above, the fine particulate dust of hydrogenated carbon attached or deposited on the surface of the tray 1A is blown off. The air containing dust flying up is duct 24
It is discharged from A and 24B. The tray 1A thus dust-removed by air blowing is sent to the next substrate desorption chamber 18.

Although the exhaust ducts 24A and 24B are connected to the upper and lower surfaces of the chamber 21 in this embodiment, the ducts may be arranged only on the upper surface or the lower surface of the chamber 21. 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 from the viewpoint of work safety and cost.

The dust removal by the dust removing device may be performed only when the amount of the fine powder of hydrogenated carbon on the tray is increased, or may be always performed 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, it is possible to reduce the error in the substrate film forming section in the state where the film forming apparatus is continuously operated without stopping the film forming operation and releasing the reduced pressure in the film forming apparatus. .

[0041]

According to the present invention, it causes an error in the film forming section,
Dust such as fine powder of hydrogenated carbon adhering to the tray can be efficiently removed while the operation is continued.

[0042]

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 formation conditions for the hydrogenated carbon film are film formation pressure 4
The tray 1 returned to the return passage 17 with mTorr and hydrogen / argon mixing ratio = 1/10 (volume ratio).
A was blown from both sides by the dust removing device 20 shown in FIG. 2, air containing dust was sucked from the lower part to perform dust removal processing, and then was used again.

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 removing device was stopped and the tray was circulated and used without performing dust removing treatment on the tray,
The number of errors shows an increasing tendency as shown in No. 2 of Fig. 3,
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.

[0048]

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. Efficiently removes fine particulate dust such as hydrogenated carbon fine powder, which causes an error, in a state where the operation is continued, thereby producing a high-quality magnetic recording medium with few errors with high yield, high productivity, and high efficiency. Can be manufactured.

According to the manufacturing method of the magnetic recording medium of the second aspect, it is possible to efficiently prevent the error of 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 type sputtering apparatus is used.
A magnetic recording medium can be manufactured with high productivity.

According to the magnetic recording medium manufacturing method of the fourth aspect, efficient dust removal processing can be performed.

[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.

2 is a configuration diagram showing a dust remover provided in the sputtering apparatus shown in FIG. 1, and shows a cross section of a portion taken along line II-II in FIG.

FIG. 3 is a graph showing a transition of an error increase rate in Example 1, No. 1 shows an example of the present invention, and No. 2 shows 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 System path 18 Substrate desorption chamber 20 Dust removal device 21 Chamber 22 Transfer device 23 Nozzle 24A, 24B Duct

Claims (4)

[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. A method of manufacturing a magnetic recording medium, wherein a treated substrate is taken out of the film forming apparatus, wherein a dust having been removed from a tray moved from the film forming apparatus. 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. 4. The method of manufacturing a magnetic recording medium according to claim 1, wherein the tray is subjected to a gas blow treatment to remove dust.