JPH02105349A - Production of magneto-optical recording medium - Google Patents

Abstract

PURPOSE:To uniformize the time when sputtering is executed by masks and to improve productivity by transferring the mask members provided between rare earth and transition metal targets and substrates together with the substrates at the time of rotating substrate holders at a specified speed in a region where both the targets are arranged in >=2 arrays and subjecting the substrates to sputtering. CONSTITUTION:The rare earth metal targets and the transition metal targets are arranged in >=2 arrays in the sputtering chamber 15 of a sputtering device 10. These targets are arranged to face each other as the targets 1a, 1b and the substrate holders 2 are disposed in the opposite regions of the targets 1a, 1b. The substrates 4 are mounted to a turn table 3 of the holders 2 and the table is rotated at a specified speed by a revolving shaft 5 disposed to the center of the table 3, then the substrates 4 are subjected to sputtering. The mask members 9 are disposed between the targets 1a, 1b and the substrates 4. The mask members 9 are formed to such shape that the apertures thereof face each of the targets 1a, 1b and the aperture width extends in the direction orthogonal with the transporting direction of the substrates 4 and expands from the center of rotation of the substrates 4 toward the outer peripheral direction.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for manufacturing a magneto-optical recording medium, and particularly to a method for manufacturing a magneto-optical recording medium in which a thin film having a multilayer structure is continuously formed by a sputtering method.

[Prior Art] In recent years, magneto-optical recording media have been widely used for large-capacity data files, etc. as magneto-optical disks that can be written and read by laser light.

This magneto-optical disk has a layer structure including a dielectric layer, a recording layer, a protective layer, etc., formed by sputtering on a transparent substrate such as glass or plastic. The recording layer exhibiting the magneto-optical effect includes at least two layers each consisting of a rare earth metal (hereinafter referred to as RE) and a layer consisting of a transition metal (hereinafter referred to as TM), each having a thickness of several to ten-odd layers. The amount of magnetization is reduced by creating a layered structure with more than one layer.

Excellent properties such as coercive force and magneto-optical effect (Kerr effect) can be obtained, and manufacturing controllability is also good.

The manufacturing method includes fixing the substrate on a rotating holder, rotating the holder above the RE target and the TM target, and passing the substrate above both the targets to separate the RM layer and the TM layer. A method of laminating at least two or more thin layers (for example, Japanese Patent Application Laid-Open No. 62-71
No. 041 and Japanese Unexamined Patent Publication No. 62-60865).

Such conventional sputtering methods have problems in mass production because they are so-called batch-type sputtering methods that require an interval time during which film formation is interrupted while a substrate holder having a rotation mechanism is replaced.

In addition, in conventional sputtering methods, a mask member that regulates the amount of sputtered particles is fixedly attached to the sputtering chamber in order to make the film thickness distribution uniform. In the case of the mechanism's sputtering method, it was extremely difficult to make the film thickness distribution uniform.

[Object of the Invention] The present invention has been made in view of the above-mentioned problems, and provides a method for manufacturing a magneto-optical recording medium that can achieve extremely high productivity compared to conventional methods and has a uniform thickness distribution of the RE layer and the TM layer. It's about doing.

[Structure of the Invention] An object of the present invention is to arrange two or more rows of rare earth metal targets and transition metal targets in a sputtering chamber in order to laminate at least a rare earth metal and a transition metal on a substrate,
The substrate facing the two targets is continuously moved along the target arrangement direction at a constant speed while being rotated at least in the area where the two targets are arranged, so that the sputtering area by the two targets is A mask member is provided between the targets and the substrate for regulating each target, and an opening of the mask member faces each target, and the width of the opening is substantially perpendicular to the direction in which the substrate is transferred. This is achieved by a method of manufacturing a magneto-optical recording medium, which is configured to have a shape that extends in the direction of the substrate and expands from the center of rotation of the substrate toward the outer circumference, and is characterized in that the mask member is transferred together with the substrate.

[Embodiments] Hereinafter, the present invention will be described in detail based on an apparatus to which the method of the present invention is applied.

FIG. 1 shows a schematic view of the main parts of a sputtering apparatus to which the method of manufacturing a magnetic recording medium of the present invention is applied, and FIG. 2 is a schematic plan view showing the positional relationship between a target and a substrate.
FIG. 3 is a plan view showing how the mask members are arranged;
FIG. 4 is a schematic plan view showing the sputtering apparatus and the transport path of the substrate holder.

As shown in FIGS. 1 and 4, the sputtering apparatus 10 has a central sputtering chamber 15 and preliminary chambers 12 at the front and rear of the sputtering chamber 15, which are separated by a partition wall 11 and partially communicated with each other. has been done. A plurality of substrate holders 2 suitably hold substrates 4 which are members to be sputtered.
are configured to be continuously transported into the sputtering apparatus 10 while being guided by guide rails 8 forming a transport path 20, for example. Therefore, since the inside of the sputtering apparatus 10 cannot be completely sealed because the substrate holder 2 moves, the sputtering chamber 15 is connected to at least each preliminary chamber 12 in order to maintain the degree of vacuum in the sputtering chamber 15 during the sputtering process. It is configured to continue evacuation by means of an evacuation means (not shown).

In the sputtering chamber 15, targets 1a and 1 are placed at the bottom.
b is provided. Said Targera) la.

1b are long and arranged in parallel along the conveyance direction of the substrate holder 2, as shown in FIG. The lengths of the target blades (la, lb) are not particularly limited, and may be appropriately determined depending on various conditions such as the conveyance speed of the substrate holder 2 and the distance between the target blades (la, lb) and the substrate 4. In short, it is sufficient that it has a length that allows the time necessary for good film formation. Further, the substrate holder 2 is configured to move to a position such that the substrate 4 is at a substantially equal distance from both the targets 1a and 1b, and on the lower side of the main body of the substrate holder 2, A rotatable turntable 3 holding the substrate 4 and a mask member 9
It is equipped with The turntable 3 has a rotating shaft 5 at its center, the rotating shaft 5 passing through the main body and extending upward, and a pinion 6 near the upper end of the rotating shaft 5.
is provided. The pinion 6 is connected to the sputtering chamber 15.
engages with the rack 7 fixed to the substrate holder 2.
By moving along the guide rail 8, the turntable 3 can be rotated in a predetermined direction.

The mask member 9 is positioned below the substrate 4 placed on the turntable 3.

That is, the mask member 9 is fixed to the substrate holder 2 by a bent connection portion.

The mask member 9 is located in the substrate holder 2 as shown by the arrow in FIG. It's dark. That is, the openings corresponding to the notched portions face each of the targets, the width of the openings extends in a direction substantially perpendicular to the transfer direction of the substrate, and extends toward the outer circumferential direction from the rotation center of the substrate 4. It is configured in a widening shape.

Therefore, a thin film with a uniform thickness distribution of each target material is laminated on the rotating substrate. Note that the targets la and lb are each connected to separate target power supplies 18.
are connected, and the Targera l-1a.

(2) Appropriate sputtering power is applied to each of b to form a desired laminated thin film.

The target layers 1a and 1b are made of a transition metal and a rare earth metal, for example, 1a is made of a transition metal and A thin film can be formed.

Note that the targets Ia and Ib do not necessarily have to have a single plate configuration, but may have a configuration in which they are divided into a plurality of plates. In addition, the divided portions are not necessarily made of the same material, but can be combined into a plurality of targets, and by this combination, the laminated structure for film formation can be adjusted as appropriate.

An inert gas such as argon (Ar) gas is introduced into the sputtering chamber 15 of the sputtering apparatus IO configured as described above, and sputtering power is appropriately applied to the targeters Ia and 1b, Said transport route 2
The substrates 4 made of glass or plastic resin on which a dielectric layer has been formed in advance are successively mounted on the substrate holder 2 at appropriate positions at the substrate holder 2 .

The substrate holder 2 is continuously transferred into the sputtering chamber 15, and while rotating in the sputtering chamber, a laminated thin film of a rare earth metal and a transition metal is formed on the substrate 4. It comes out. The substrates 4 can be removed one after another from the substrate holder 2 that has come out, allowing the process to proceed to the next step.

As described above, according to the present invention, by performing sputtering while continuously moving the target along the direction of arrangement of the targets, the time required to form the desired laminated thin film can be sufficiently covered while the substrate 4 is moving. Since the mask member moves together with the substrate, the time (area) exposed to the plasma of the RE target and the 1M target at the position in the rotational radial direction of the substrate is determined. It is possible to make the film thickness distribution uniform and to improve high productivity with the laminated structure. In particular, when target rows consisting of multiple types of targets divided in the direction of transfer of the substrate holder 2 are provided in parallel along the transfer direction, film formation of any laminated structure can be freely performed depending on the arrangement. This greatly increases the productivity and the range of film formation adjustment.

In the embodiment, the T. targera) la.

(b) Both targets 1a and 1b are provided almost horizontally, but the arrangement is not limited to this.
It may be made to have an appropriate inclination in the target width direction (direction perpendicular to the substrate holder transfer direction) such that the opposite side approaches the substrate 4 than the adjacent portion. Although not mentioned in the embodiment, the targets 1a and 1
It is desirable to provide a partition plate in the area adjacent to b because it can improve the quality of film formation.

In the embodiment, an example is shown in which one substrate 4 is mounted on the turntable 3 of the substrate holder 2 and transferred while rotating, but the apparatus to which the present invention is applied is not limited to this. It goes without saying that a sufficient effect can be expected even if a plurality of substrates are attached to a substrate holder and the substrates are transferred while rotating or rotating to form a film.

[Effects of the Invention] As described above, in the method for manufacturing a magnetic recording medium of the present invention, in order to laminate at least a rare earth metal and a transition metal on a substrate, two rows of rare earth metal targets and transition metal targets are arranged in a sputtering chamber. Sputtering is performed by continuously transporting the substrate arranged as above and facing both the targets at a constant speed along the target arrangement direction while rotating at least in the region where both the targets are arranged. Therefore, the time required to form the desired laminated thin film can be secured while the substrate is moving, and when the target has a split structure, the deposition adjustment of the laminated thin film is extremely easy and the adjustment range is wide. Moreover, since it is continuously conveyed, extremely high production efficiency can be obtained compared to conventional batch-type or even intermittent-type sputtering methods.

Furthermore, a mask member having an opening width extending in a direction substantially perpendicular to the transfer direction of the substrate and expanding in the outer circumferential direction from the rotation center of the substrate is provided above the substrate, and sputtering is performed through the mask member. , by keeping the amount of target particles flying from the target constant and reaching the substrate surface.
The film thickness distribution can be made uniform.

[Examples] The effects of the present invention can be further clarified with the following examples.

An example carried out using the apparatus shown in FIG. 1 and the mask member shown in FIG. 3 will be described.

On a plastic substrate 4 with a thickness of 1.2 mm and a diameter of 130 mm, a silicon nitride (Si3N4) film with a thickness of 800 mm was formed as a dielectric layer by a sputtering method, and recording of alternate lamination of RE layers and TM layers was performed using the following method. A layer was deposited.

As an RE target, size 80mm x 500mm
A total of five sheets of Tb target) la were arranged with sides of 80m+n adjacent to each other. Also, as TM Tsutaat,
FeesC with the same size of 80mmX 500+n+n
Similarly to the Tb target, the O+s alloy target 1b was
A total of five sheets were arranged with their short sides adjacent to each other, and the distance between both targets was set to 40 mm. After reducing the initial vacuum level in the sputtering chamber to 110 Torr or less, Ar gas was introduced into the same chamber to achieve a vacuum level of I x 10'' Torr. Next, 1100 W per Tb target (80 mm x 500 mm), and FeesCO+s1 piece (80m
The plastic substrate 4 on which a dielectric layer has been formed in advance is held on the turntable 3 and attached to the substrate holder 2, and the plastic substrate 4 is held at a position 150m+n away from each Targetera) Ia and lb for 10m+++. /sec speed and 13r
While rotating at pm, the substrate holder was continuously supplied and transferred to form a recording layer of alternately laminated RE layers and TM layers. Thereafter, analysis using Auger electron spectroscopy and small-angle X-ray scattering revealed that the Tb layer had 10 layers, the FeasCO+s layer had 12 layers, and the total film thickness was 900A. Further, when the film thickness within the plastic substrate (φ130++++n) was measured by the step method, the film thickness distribution was ±2.8%.

Further, a silicon nitride film having a thickness of 100 OA was formed as a protective layer. After that, the magnetic properties of the recording layer were measured using a vibrating sample magnetometer and a Kerr hysteresis measuring device, and as a result, Hc
(holding force) is 15KOe or more, θk (Kerr rotation angle) is 0
．． The temperature was 43 degrees, and the Tc (Curie temperature) was 165 degrees Celsius.

[Comparative example] Next, a conventional method will be explained as a comparative example.

A recording layer was formed using a rotating substrate holder capable of mounting six plastic resin substrates. The condition is diameter 20
A sputtering power of 900W was applied to a target made of Tb material with a diameter of 0+nm, and a sputtering power of 900W was added to the other target with a diameter of 200+nm.
A sputtering power of 2200 W was applied to discharge the material using FeasCO+s material. At that time, the mask member was removed, the substrate holder was rotated at a rotation speed of 15 rpm, and open film formation was performed for 3 minutes under the conditions of the above example. As a result, there were 10 people in the Tb layer and 13 people in the Fe85coIs layer.
A recording layer with a total thickness of 100 OA could be obtained.

Thereafter, the magnetic properties of the recording layer were measured using a vibrating sample magnetometer and a Kerr hysteresis measuring device in the same manner as in the example. As a result, Hc (coercive force) was 15 KOe or more, and θk (Kerr rotation angle) was 0.44 degrees.

Tc (Curie temperature) was 165°C. Further, when the film thickness within the plastic substrate was measured by the step method, the film thickness distribution was ±6.7%.

As is clear from the above results, raw material according to this comparative example = 13
- The production rate was such that approximately two substrates were produced per minute. Furthermore, it was found that the film thickness distribution of this example was much better than that of the comparative example.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of the main parts of a sputtering apparatus to which the method of manufacturing a magnetic recording medium of the present invention is applied, FIG. 2 is a schematic plan view showing the positional relationship between the target and the substrate, and FIG. 3 is the arrangement of mask members. FIG. 4 is a schematic plan view showing the sputtering apparatus and the transport path of the substrate holder. Reference symbols la, lb...target, 2...substrate holder, 3...turntable, 4
... Board, 5... Rotating shaft, 6... Pinion, 7... Rack, 8... Guide rail, 9
...Mask member, 10... Sputtering device, 11... Partition wall, 12... Preliminary chamber, 15... Sputtering chamber, 18... Target power source, 20... Transport route.

Claims (1)

[Claims] In order to laminate at least a rare earth metal and a transition metal on a substrate, two or more rows of rare earth metal targets and transition metal targets are arranged in a sputtering chamber, and the substrate facing both the targets is placed so that at least both of the targets Disposed between the two targets and the substrate in order to transport the target continuously along the target array direction at a constant speed while rotating in the disposed area, and to restrict the sputtering area by the two targets, respectively. The mask member has a shape in which the opening of the mask member faces each of the targets, the opening width thereof extends in a direction substantially perpendicular to the transfer direction of the substrate, and widens toward the outer circumference from the rotation center of the substrate. A method for manufacturing a magneto-optical recording medium, characterized in that the mask member is transferred together with the substrate.