JPH1053860A - Sputtering apparatus and method for manufacturing magnetic recording medium - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To prevent abnormal discharge in the step of forming a carbonaceous protective layer. SOLUTION: In a sputtering apparatus arranged so that a plate surface of a carbon target 1 is in a vertical direction,
Atmosphere gas flows from above the carbon target 1 to below. A magnetic recording medium is manufactured by forming a carbonaceous protective layer on a substrate using this sputtering apparatus. [Effect] By changing the gas supply direction from the conventional horizontal direction to the vertical direction, the occurrence of abnormal discharge can be greatly reduced. A high-quality magnetic recording medium can be manufactured with high productivity without causing abnormal discharge for a long time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sputtering apparatus and a method for manufacturing a magnetic recording medium, and more particularly, to a sputtering apparatus in which the frequency of occurrence of abnormal discharge during the formation of a carbonaceous thin film is reduced to increase the productivity and such a sputtering apparatus. The present invention relates to a method for manufacturing a magnetic recording medium using a simple sputtering apparatus.

[0002]

2. Description of the Related Art In recent years, with the development of information processing technology such as computers, magnetic recording media such as magnetic disks have been widely used as external storage devices.

Conventionally, as a magnetic recording medium, generally, a substrate made of an aluminum alloy, glass, or the like is subjected to a non-magnetic plating treatment such as alumite treatment or Ni-P plating.
A magnetic disk is used in which a base layer of Cr or the like is formed, a magnetic layer of a Co-based alloy is formed, and a carbonaceous protective layer is further formed.

In such a magnetic disk, the distance between the magnetic disk and the magnetic head at the time of recording / reproducing, that is, the flying height of the magnetic head is becoming smaller and smaller in recent years. Below.

As described above, since the flying height of the magnetic head is extremely small, if the surface of the magnetic disk is distorted, a head crash may be caused and the surface of the magnetic disk may be damaged. Further, even a minute undulation that does not lead to a head crash tends to cause various errors in reading and writing information. For this reason, a high quality magnetic disk having no defects on its surface is required.

Incidentally, the carbonaceous protective layer of a magnetic disk is generally formed by using a pass-through type sputtering device, mounting a disk-shaped substrate on a tray, and sequentially transporting the substrate by a transport device. In such a sputtering apparatus, as the number of times of film formation increases, a film-forming component generated at the time of sputter film formation adheres and deposits on a non-sputter region or a transfer device such as a tray in the sputtering apparatus. In particular, the deposited film components cause dielectric breakdown, causing abnormal discharge, causing sparks,
Discharge becomes unstable.

Further, when the deposit causes dielectric breakdown, an overcurrent flows through the broken portion, and a lump of molten material is scattered.
This causes the defects (abnormal protrusions) to adhere to the film forming portion on the substrate side and increase. In addition, the sediment separates and scatters,
Defects also occur when this adheres to the film forming unit on the substrate side.

Therefore, in the conventional method, when an abnormal discharge increases during the film formation, the film formation is interrupted, and the insulating deposition adhered to a non-sputtering area in the sputtering apparatus or a transfer device such as a tray. The film needs to be removed periodically.

In a conventional sputtering apparatus, a carbon target for forming a carbonaceous protective layer is disposed so that its plate surface is vertically oriented, as shown in FIG. Gas is supplied in a substantially horizontal direction along the plate surface of the carbon target 1 from gas supply pipes 2A and 2B provided on both sides of the carbon target 1 as shown by an arrow X.

[0010]

However, in order to remove the insulating deposits attached to the non-sputtering area in the film forming apparatus and the transfer device such as a tray, the sputter film forming is interrupted. Since it is necessary to release the reduced pressure in the film forming apparatus, productivity is significantly reduced.

The present invention solves the above-mentioned conventional problems, prevents abnormal discharge in the process of forming a carbonaceous protective layer, and enables a high-quality magnetic recording medium to be manufactured with good yield. An object of the present invention is to provide a method for manufacturing a magnetic recording medium using a sputtering device.

[0012]

SUMMARY OF THE INVENTION A sputtering apparatus according to the present invention is a sputtering apparatus for forming a carbonaceous layer on a substrate, comprising: a target disposed so that a plate surface is arranged in a vertical direction; And a gas supply means for supplying an atmospheric gas to the plate surface of the sputtering apparatus, wherein the gas supply means flows the gas downward from above the target.

The method of manufacturing a magnetic recording medium according to the present invention comprises the step of forming a carbonaceous protective layer on a substrate by sputtering, the method comprising the steps of: Forming a layer.

That is, the present inventors have studied to prevent abnormal discharge in the process of forming the carbonaceous protective layer. As a result, it was found that the occurrence of abnormal discharge can be greatly reduced by changing the gas supply direction. Was found.

According to the present invention, by flowing an atmospheric gas from above the target to below, the abnormal discharge in the film forming process can be greatly reduced.

[0016]

Embodiments of the present invention will be described below in detail with reference to the drawings.

As shown in FIG. 1 (perspective view) and FIG. 2 (front view), the sputtering apparatus according to the present invention uses an atmosphere gas supply pipe 3 of a carbon target 1 having a plate surface arranged in a vertical direction. An atmosphere gas such as argon is provided along the plate surface of the carbon target 1 from the upper side to the lower side as indicated by an arrow Y as shown in FIG. In FIG. 2, the earth shield 4 and the like are not shown.

The diameter of the gas supply pipe 3, the diameter of the gas ejection hole,
The arrangement interval (pitch) of the gas ejection holes and the like vary depending on the size of the carbon target and the like. In a normal case, if the carbon target has a plate surface of about 10 to 30 cm × 20 to 70 cm, the horizontal portion The length is 20-60c
m, it is preferable to use one in which gas ejection holes having a hole diameter of about 0.05 to 0.2 cm are provided at intervals of 3 to 8 cm in the horizontal portion.

The sputtering apparatus of the present invention can employ the same configuration as the conventional sputtering apparatus except that the supply direction of the atmospheric gas to the carbon target 1 is changed as described above.

When a magnetic recording medium is manufactured using such a sputtering apparatus, a disk-shaped substrate made of an aluminum alloy, glass, or the like is generally used as the substrate, and the substrate is usually processed to a predetermined thickness. After that, the surface is mirror-finished as necessary, and then a nonmagnetic metal, for example, a Ni-P alloy, or a Ni-Cu-P alloy or the like underlayer is formed to a thickness of about 5 to 20 μm by electroless plating or the like. Formed. Next, a texturing process is performed on the base layer of the substrate to form fine grooves or irregularities on the surface of the substrate.
By this texture processing, adsorption between the magnetic head and the substrate can be prevented, CSS characteristics are improved, and magnetic anisotropy is further improved.

Next, after a Cr layer is formed as a second underlayer on the substrate by sputtering, a magnetic layer and a protective layer are sequentially formed. The thickness of the Cr underlayer is usually 50
In the range of Å2000 °.

As the magnetic layer formed on the Cr underlayer of such a substrate, Co-Cr, Co-Ni, Co-C
A magnetic metal thin film layer of a Co-based alloy represented by rX, Co-Ni-X, Co-WX or the like is preferable. Here, X is Li, Si, Ca, Ti, V, Cr, Ni, A
s, Y, Zr, Nb, Mo, Ru, Rh, Ag, Sb,
Hf, Ta, W, Re, Os, Ir, Pt, Au, L
One, two or more elements selected from the group consisting of a, Ce, Pr, Nd, Pm, Sm and Eu.

The magnetic layer made of such a Co-based alloy is
Usually, it is formed on the base layer of the substrate by sputtering or the like. The thickness of the magnetic layer is usually in the range of 200 to 2500 °.

After forming the underlayer and the magnetic layer, a carbonaceous protective layer is formed as a protective layer. The carbonaceous protective layer is generally formed on the magnetic layer by a sputtering method using diamond, graphite or amorphous carbon as a target in a rare gas atmosphere such as argon or helium. Alternatively, a hydrogenated carbon film or a nitrogenated carbon film may be formed by mixing hydrogen, nitrogen, air, or the like in a sputtering atmosphere. The thickness of the protective layer thus formed is usually in the range of 100 to 1000 °.

After the formation of the protective layer, the tape is cleaned in a usual manner. After the tape cleaning step is completed, the product is usually provided with a lubricant layer on the surface of the protective layer. In this case, as the lubricant, for example, a fluorine-based liquid lubricant is used, and the lubricant layer is usually formed to a thickness of about 15 to 50 ° on the protective layer by a dip coating method, a spin coating method, a spray coating method, or the like. Formed.

[0026]

The present invention will be described more specifically with reference to the following examples.

Example 1 As shown in FIGS. 1 and 2, an argon gas was formed to flow from above to below along the plate surface of a carbon target from a gas supply pipe provided along the upper edge of the carbon target. The carbonaceous layer was continuously formed using a passing type sputtering apparatus.

The carbon target used had a plate surface size of 23 cm × 64 cm, and the gas supply pipe had a horizontal section having a pipe diameter of 1.7 cm, a length of 300 mm, and a gas jet having a hole diameter of 0.5 cm. It is made of SUS304 in which six holes are provided at a pitch of 50 cm.

When the gas supply pipe was changed in this way and the carbonaceous layer was formed by sputtering under the same conditions, the conventional sputtering apparatus shown in FIG.
The number of abnormal discharges occurring about 00 times / hour is 1 to 10
The number of times / hour was sharply reduced, and sputtering film formation was performed without interrupting the operation for about 20 days.

[0030]

As described above in detail, according to the sputtering apparatus of the present invention, the abnormal discharge in the sputter deposition of the carbonaceous layer can be greatly reduced, and the production efficiency can be increased. Further, according to the method for manufacturing a magnetic recording medium of the present invention using such a sputtering apparatus, abnormal discharge in the step of forming the carbon protective layer is prevented, and a high-quality magnetic recording medium can be produced with high productivity. It can be manufactured with good yield.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a carbon target and a gas supply pipe according to an embodiment of a sputtering apparatus of the present invention.

FIG. 2 is a front view showing a carbon target and a gas supply pipe according to the embodiment of the sputtering apparatus of the present invention.

FIG. 3 is a front view showing a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Carbon target 3 Gas supply pipe 4 Earth shield 5 Chimney

Claims (2)

[Claims] 1. A sputtering apparatus for forming a carbonaceous layer on a substrate, comprising: a target arranged so that a plate surface thereof is arranged in a vertical direction; and a sputtering device for supplying an atmosphere gas to the plate surface of the target. A sputtering apparatus comprising: a gas supply unit; wherein the gas supply unit flows a gas downward from above a target. 2. A method for manufacturing a magnetic recording medium comprising a step of forming a carbonaceous protective layer on a substrate by sputtering, wherein the carbonaceous protective layer is formed using the sputtering apparatus according to claim 1. A method for manufacturing a magnetic recording medium.