JPH05171409A - Device for producing magneto-optical recording medium - Google Patents

Abstract

PURPOSE:To produce a magneto-optical disk with the variations in laser beam intensity reduced from the inner periphery to the outer periphery of the disk. CONSTITUTION:A substrate 1 is rotated in a plane by a rotating machine 3, and a vaporization source 5 is supported between a couple of electrodes 4. A first film thickness correcting mask 7a and a second film thickness correcting mask 7b are set in a vacuum vessel 14, moved along a guide rail 12 and introduced into a vacuum vessel 13. A film thickness uniformizing mask is supported by a support 9 and arranged on the vaporization source side of the film thickness correcting masks. The film thickness uniformizing mask is rotated in the plane by a rotating machine 10. Consequently, a specified distribution of film thickness is obtained even if a substrate and the film thickness correcting mask are not arranged directly above the vaporization source, and a film is formed on plural substrates at the same time.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a magneto-optical recording medium manufacturing apparatus, and more particularly to a magneto-optical recording medium manufacturing apparatus for recording, reproducing and erasing information by using a laser beam.

[0002]

2. Description of the Related Art In the magneto-optical recording system, a so-called CAV system is widely used in which a magneto-optical disk is rotated at a constant rotational speed in order to simplify a magneto-optical recording device. It is necessary to heat the portion of the magneto-optical disc where the recording is performed with laser light to a certain temperature or higher. However, in the CAV method, since the number of revolutions of the disc is constant, the linear velocity in the laser irradiation portion is different between the inner circumference and the outer circumference. Becomes faster toward the outer circumference, and the thermal efficiency decreases, so it is necessary to irradiate stronger laser light toward the outer circumference. The magneto-optical disk drive reads the laser light intensity information previously recorded on the control track of the disk and controls the laser light intensity.

Recording on a magneto-optical disk is performed by raising the temperature of the recording film above the Curie point with a semiconductor laser and decreasing the temperature while applying an external magnetic field to create a region magnetized in the direction of the external magnetic field. , Information of "1" is recorded. When the magneto-optical disk rotates at a constant number of revolutions, the linear velocity increases in proportion to the distance from the center of the disk. It is necessary to strengthen the laser light. That is, the laser beam intensity required for recording is higher on the outer peripheral side than on the inner peripheral side. Therefore, when driving the magneto-optical disk, it is necessary to increase the power margin of the semiconductor laser in order to increase the intensity of the recording laser light stepwise or continuously from the inner circumference side to the outer circumference side. However, it complicates the power control circuit and the like, which is a burden on the drive side.

[0004]

The present invention has been made in view of the above circumstances, and it is possible to manufacture a magneto-optical disk capable of manufacturing a magneto-optical disk with a small change in laser light intensity required for recording from the inner circumference to the outer circumference of the disk. It is made for the purpose of providing a medium manufacturing apparatus.

[0005]

In order to achieve the above object, the present invention provides (1)
A vacuum chamber for vacuum vapor deposition, a plurality of evaporation sources, a substrate holder that faces the evaporation sources and holds a plurality of disk-shaped substrates, and is disposed between the evaporation source and the substrate holder. The first mask for correcting film thickness, in which the film thickness is changed continuously or stepwise in the radial direction of the substrate and the opening is set so that the film thickness on the outer peripheral side is smaller than that on the inner peripheral side. And a second mask for correcting film thickness in which an opening is set so that the film thickness on the outer peripheral side is larger than that on the inner peripheral side, and the storage of the film thickness correcting mask connected to the vacuum chamber. An auxiliary vacuum tank for replacement, a defining means for defining the positional relationship between the first and second film thickness correcting masks and the substrate, and the first and second film thickness correcting masks for the two vacuums. The moving means for moving between the tanks and the vapor deposition sources on the evaporation source side with respect to the first and second masks for film thickness correction. A film thickness uniformizing mask arranged so as to correspond to the source, wherein the film thickness uniformizing mask is rotated in-plane and the substrate is rotated in-plane while performing vacuum deposition, or 2) A sputtering vacuum chamber, a plurality of targets, a substrate holder that faces the targets and holds a disk-shaped substrate, and is disposed between the target and the substrate holder, and the film thickness is the diameter of the substrate. The first film thickness correction mask in which the opening is set so that the film thickness on the outer peripheral side is smaller than that on the inner peripheral side in this case. Is a second mask for film thickness correction in which an opening is set so that the outer peripheral side has a larger film thickness than the inner peripheral side, and an auxiliary vacuum tank for storing and replacing a mask holder connected to the vacuum tank. , The first and second
From the defining means for defining the positional relationship between the film thickness correcting mask and the substrate, and the film thickness uniformizing mask arranged so as to correspond to each of the targets on the target side of the film thickness correcting mask. The film thickness uniformizing mask is rotated in-plane and the substrate is rotated in-plane while performing sputtering film formation, or (3) a vacuum chamber for ion plating, and a plurality of evaporation sources. A substrate holder that faces the evaporation source and holds a disk-shaped substrate, and is arranged between the evaporation source and the substrate holder to change the film thickness continuously or stepwise in the radial direction of the substrate, At that time, a first film thickness correction mask in which an opening is set so that the film thickness on the outer peripheral side is smaller than that on the inner peripheral side, and the film on the outer peripheral side has a film thickness larger than that on the inner peripheral side. A second film thickness correction mask having an opening set to have a large thickness; An auxiliary vacuum chamber for accommodating and replacing the film thickness correcting mask connected to the vacuum chamber, a defining means for defining a positional relationship between the first and second film thickness correcting masks and the substrate, A moving means for moving the first and second film thickness correction masks between the two vacuum chambers, and an evaporation source which is arranged so as to correspond to each evaporation source rather than the first and second film thickness correction masks. It is characterized in that the film thickness uniformizing mask is rotated, and the film thickness uniforming mask is rotated in-plane and the substrate is ion-plated while rotating in-plane. Hereinafter, description will be given based on examples of the present invention.

FIG. 1 is a block diagram for explaining an embodiment of an apparatus for manufacturing a magneto-optical recording medium according to the present invention. In the figure, 1 is a substrate, 2 is a substrate holder, 3 is a rotation introducing machine, and 4 is a support. The electrode also serving as a body, 5 is an evaporation source, 6 is a support, 7a is a first film thickness correction mask, 7b is a second film thickness correction mask, 7c is a stopper, 8 is an electrode, 9 is a support, and 10 is a rotating member. Introduction machine, 11
Is a mask for uniform film thickness, 12 is a guide rail, 13, 1
4 is a vacuum chamber, and 15 is a gate valve.

The vacuum chamber 13 and the auxiliary vacuum chamber 14 are connected via a gate valve 15. Substrate 1 is rotation introducing machine 3
It is possible to rotate within the plane. The pair of support / electrode 4 supports a resistance heating evaporation source 5 therebetween.
Instead of such an evaporation source, an evaporation source used in a conventional vacuum evaporation method such as a beam evaporation source can be appropriately used. At this time, the distribution of the vaporized particles can be regarded as sufficiently rotationally symmetric at the position of incidence on the mask for uniforming the film thickness.

The first film thickness correction mask 7a and the second film thickness correction mask 7b are normally located in the auxiliary vacuum chamber 14, and are moved along the guide rails 12 as necessary, so that the inside of the vacuum chamber 13 is moved. Will be introduced to. At this time, the shape of the film thickness correction mask has an opening 16 and a tapered portion 17 as shown in FIGS. 2A and 2B. There is a stopper 7c having a shape corresponding to the tapered portion of the mask, and the film thickness correcting mask is fixed in a state where the position is defined so that the center of the film thickness correcting mask and the center of the substrate are finally coaxial. Further, the film thickness uniformizing mask 11 is supported by the support 9, and is arranged closer to the evaporation source than the film thickness correcting mask. Further, the mask 11 for uniforming the film thickness is rotated in-plane by the rotation introducing machine 10. As a result, even if the substrate and the mask for film thickness correction are not necessarily arranged directly above the evaporation source, the film thickness distribution can be set to a predetermined distribution, and it is possible to simultaneously form films on a plurality of substrates. Become.

FIG. 3 is a view showing a mask for uniforming the film thickness.
The shaded area in the figure is the shielding portion. γ (r) = a / f (r) γ: Sum of opening angles at the distance r from the mask center f (r): Distribution of vaporized substances incident on the mask for uniform film thickness (calculated value or measured value) a : Positive constant and opening angle are set.

As shown in FIG. 4, the opening of the first mask for correcting film thickness has an opening angle of, for example, γ ′ (r) = − b · r + d γ ′: sum of opening angles at a distance r from the mask center b , D: It is set so as to be a positive constant, and the in-plane distribution of the vaporized substance after passing through is corrected so that the film thickness is smaller on the outer peripheral side than on the inner peripheral side. The openings need not necessarily be continuous and may be divided into a plurality of opening areas as shown in FIGS. 5 (a) and 5 (b).

FIG. 6 shows a second film thickness correcting mask, the opening angle of which is γ ″ (r) = c · r + e γ ″: the sum of the opening angles at a distance r from the mask center c, e : It is set as a positive constant. Also in this case, the openings need not necessarily be continuous and may be divided into a plurality of opening regions as shown in FIGS. 7 (a) and 7 (b).

The electrode 4 which also serves as a support is a conductor and also serves as an electrode, and the ends of the electrodes 4 projecting outside the vacuum chamber are connected to a power source 8 as shown in the figure. The grounding in the figure is not always necessary. actually,
These electrical connections include various switches, and these operations realize the film forming process, but these switches are not shown in the figure.

The method of manufacturing the magneto-optical recording medium according to the above embodiment will be described below. The substrate 1 is set on the substrate holder 2 as shown in FIG. 1, and the evaporation material is held by the evaporation source 5. The base material forming the evaporation material is determined according to what kind of thin film is formed. For example, when Al (aluminum) is used for the reflective layer, metallic Al is used, and when Cr is used, metallic Cr is used as a base material. Here, for the sake of explanation, the reflective layer is an Al film. First, the first film thickness correction mask 7a is moved to the vacuum chamber 13, and the film thickness correction mask is fixed to the stopper 7c. In the present embodiment, the film thickness correction mask and the stopper are formed in a tapered shape with unevenness. At this time, the second film thickness correcting mask 7b is in the vacuum chamber 14.

The inside of the vacuum chamber is 10 ⁻⁵ to 10 ⁻⁶ Torr in advance.
To the pressure of. In this state, the power source 8 is operated to heat the evaporation source 5 to evaporate the evaporation substance. In addition, the substrate holder 2 rotates in-plane during vapor deposition. The vaporized material flies toward the substrate side, but when it passes through the mask for uniforming the film thickness whose opening angle is set as described above, its in-plane distribution is made uniform, and the mask for correcting the film thickness is further formed. After being corrected to a desired distribution by 7a, it flies to the substrate side. When the first film thickness correcting mask 7a is used, the film thickness is changed continuously or stepwise in the radial direction of the substrate,
At that time, the film is formed so that the outer peripheral side has a smaller film thickness than the inner peripheral side. The thicker the Al film thickness of the reflective layer, the greater the thermal diffusion due to heat conduction, and the larger the laser power required to heat the recording layer to a recordable temperature. Therefore, if the film thickness of Al of the reflective layer becomes smaller toward the outer peripheral side, the change in laser power between the inner peripheral side and the outer peripheral side can be reduced.

In the magneto-optical recording medium manufacturing apparatus of claim 1, when the second dielectric protective layer is formed, the second dielectric protective layer having a thermal conductivity smaller than that of the metal film, for example, SiO _{2 is used.}
Alternatively, the smaller the film thickness of SiO or the like, the greater the heat loss due to heat conduction to the reflective layer, and the greater the laser power required to heat the recording layer to a recordable temperature.
Therefore, as the second dielectric protection layer, for example, the first film thickness correction mask 7a is moved to the vacuum chamber 14, and instead the second film thickness correction mask 7b is introduced into the vacuum chamber 13 so that the film thickness is on the outer peripheral side. If the SiO ₂ film is formed by using the electron beam evaporation source so that it becomes larger, the change in the laser power between the inner peripheral side and the outer peripheral side can be reduced.

Further, for example, when forming a magnetic layer of a Tb, Fe, Co-based alloy, the film should be formed from each metal evaporation source of Tb, Fe, Co without interposing a mask for film thickness correction. Thus, the magnetic layer can be formed uniformly, and a stable magneto-optical recording medium can be manufactured in which the life of the magnetic layer does not vary depending on the position on the substrate. Also,
In the present invention, since the film thickness correction mask can be taken out and replaced without exposing the film forming vacuum chamber to the atmosphere, the film forming vacuum chamber can be contaminated with evaporative substances while keeping the film forming vacuum chamber clean. You can replace the old mask with a new one,
It is possible to manufacture a magneto-optical recording medium having stable characteristics. Thus, in order to solve the problems of the present invention, by providing a means for continuously or stepwise changing the film thickness of the film provided on the substrate from the inner peripheral side to the outer peripheral side of the substrate. Can be achieved.

As described above, in the magneto-optical recording medium manufacturing apparatus of the first aspect, the vacuum chamber 13 for vacuum deposition and the auxiliary vacuum chamber 14 are provided.
And a plurality of evaporation sources 5 and a substrate holder 2 that holds the plurality of disk-shaped substrates 1 facing the evaporation sources 5, and a film thickness is set between the evaporation sources 5 and the substrate 1. Of the first film thickness correcting mask 7a for changing the distribution continuously or stepwise in the radial direction so that the film thickness on the outer peripheral side is smaller than that on the inner peripheral side. It is possible to dispose the second film thickness correction mask 7b set so that the film thickness is larger than that on the inner peripheral side. Moreover, the mask for film thickness correction can be moved between the vacuum chamber 13 for vacuum deposition and the auxiliary vacuum chamber 14 as needed. Further, when the masks are introduced into the vacuum chamber 13 for vacuum deposition, the masks for film thickness correction are set so that the positions of the masks for film thickness correction and the center of the substrate can be defined coaxially. A stopper 7c for fixing is provided in the vacuum chamber for vacuum vapor deposition. Further, a film thickness uniformizing mask 11 corresponding to each evaporation source 5 is arranged between the evaporation source 5 and the film thickness correction mask.

The substrate 1 can be rotated in-plane by the rotation introducing machine 3. Further, the mask 1 for uniform film thickness
1 can be rotated in-plane by the rotation introducing machine 10. The center of the film thickness correction mask and the center of the substrate are coaxial, and the center of the film thickness uniforming mask and the center of the evaporation distribution are coaxial.

The evaporation material from the evaporation source 5 has a uniform in-plane distribution when passing through the film thickness uniforming mask 11.
Further, when passing through the film thickness correction mask, its in-plane distribution is corrected to a desired distribution, and the film flies to the substrate side.
When the first film thickness correction mask 7a is used, the film thickness is continuously or stepwise changed in the radial direction of the substrate by setting the opening of the film thickness correction mask, and the outer peripheral side is inward at this time. The distribution is modified so that the film thickness is smaller than on the peripheral side. At this time, the film thickness correction mask or the substrate holder 2
Since at least one of them rotates in the plane and the mask 11 for uniforming the film thickness rotates in the plane, shadows of the mask for film thickness correction and the mask 11 for uniforming the film thickness do not occur. When the second film thickness correction mask 7b is used, the opening of the film thickness correction mask for correcting the in-plane distribution of the vaporized substance when passing through the film is closer to the outer peripheral side than to the inner peripheral side. The thickness is set to be large.

FIG. 8 is a view showing another embodiment of the magneto-optical recording medium manufacturing apparatus according to the present invention, in which 21 is a substrate and 22 is a substrate.
Is a substrate holder, 23 is a rotation introducing machine, 24 is a support / electrode, 25 is a target, 26 is a support, 27a is a first film thickness correcting mask, 27b is a second film thickness correcting mask, 27
c is a stopper, 28 is a power source, 29 is an electrode also serving as a support,
Reference numeral 30 is a rotation introducing machine, 31 is a mask for uniform film thickness, 32 is a guide rail, 33 and 34 are vacuum chambers, and 35 is a gate valve.

The vacuum chamber 33 and the auxiliary vacuum chamber 34 are connected via a gate valve 35. The substrate 21 can rotate in-plane by the rotation introducing machine 23. Support and electrode 2
4 supports the target 25. The first film thickness correction mask 27a and the second film thickness correction mask 27b are usually inside the vacuum chamber 34, and are introduced into the vacuum chamber 33 by moving along the guide rail 32 as necessary. At this time, the shape of the film thickness correction mask is as shown in FIG.
As shown in (b), it has an opening 36 and a tapered portion 37, and there is a stopper 27c having a shape corresponding to the tapered portion of the film thickness correction mask at the moving destination, and finally the film thickness. The film thickness correction mask is fixed in a state where the position is defined such that the center of the correction mask and the center of the substrate are coaxial. Further, a mask 31 for uniform film thickness is supported by the electrode 29 which also serves as a support, and is arranged closer to the target side than the mask for film thickness correction. Further, the film thickness uniformizing mask 31 is rotated in-plane by the rotation introducing machine 30.
With this, even if the substrate and the mask for correcting the film thickness are not necessarily arranged immediately above the target, the film thickness distribution can be set to a predetermined distribution, and it is possible to simultaneously form films on a plurality of substrates. ..

FIG. 10 is a view showing a mask for uniforming the film thickness.
The shaded area in the figure is the shielded area. γ (r) = a / f (r) γ: Sum of aperture angles at the distance r from the mask center f (r): Distribution of particles from the target incident on the mask for uniform film thickness (calculated value or measured value) ) A: Positive constant and opening are set. Here, the openings may be meshed in order to stabilize the discharge.

As shown in FIG. 11, the opening of the first film thickness correcting mask has an opening angle of γ '(r):-b * r + d γ' (r): an opening angle at a distance r from the mask center. Total b, d: It is set to be a positive constant, and after the particles from the target pass, the in-plane distribution is corrected so that the film thickness on the outer peripheral side is smaller than that on the inner peripheral side. .. The openings need not necessarily be continuous and may be divided into a plurality of opening regions as shown in FIGS. 12 (a) and 12 (b).

FIG. 13 shows a second film thickness correcting mask, the opening angle of which is γ ″ (r) = c · r + e γ ″: the sum of opening angles at a distance r from the mask center c, e : It is set as a positive constant. Also in this case, the openings need not necessarily be continuous and may be divided into a plurality of opening areas as shown in FIGS. 14 (a) and 14 (b).

The support / electrode 24 is also a conductor and also serves as an electrode. The ends of the electrodes 24 protruding outside the vacuum chamber are connected to the negative terminal of the power source 28 as shown in the figure. The positive terminal of the power source 28 is the electrode 29 also serving as the support
Has been succeeded to. The installation in the figure is not always necessary. Actually, these electrical connections include various switches, and these operations realize the film forming process, but these switches are not shown in the drawing.

The method of manufacturing the magneto-optical recording medium according to the second embodiment will be described below. The substrate 21 is set on the substrate holder 22 as shown in FIG. 8, and the target 25 is held by the electrode 24 also serving as the support. The base material forming the target is determined according to what kind of thin film is formed. For example, when Al is used as the reflective layer, metal Al is used instead of C
When r is used, metallic Cr is used as a base material. Here, for the sake of explanation, the reflective layer is an Al film.

First, the first film thickness correction mask 27a is moved to the vacuum chamber 33, and the film thickness correction mask is stopped by the stopper 27.
Fix at c. In the present embodiment, the film thickness correction mask and the stopper are formed in a tapered shape with unevenness. At this time,
The second film thickness correction mask 27b is located inside the vacuum chamber 34. The pressure in the vacuum chamber is set to 10 ⁻⁵ to 10 ⁻⁶ Torr in advance, and then Ar gas is introduced to a pressure of 10 ⁻² Torr.
In this state, the power supply 28 is operated to sputter the target to form a film. Also, the substrate 21 is used during sputtering.
Is spinning in the plane. The particles from the target fly toward the side of the substrate, but when passing through the mask 31 for uniforming the film thickness whose opening angle is set as described above, the in-plane distribution thereof is uniformized, and the film thickness is further increased. After being corrected to a desired distribution by the correction mask 27a, it flies toward the substrate. In the first film thickness correction mask 27a, the film thickness is continuously or stepwise changed in the radial direction of the substrate, and the film is formed so that the film thickness is smaller on the outer peripheral side than on the inner peripheral side. To do.

The thicker the Al film thickness of the reflective layer, the greater the thermal diffusion due to heat conduction, and the greater the laser power required to heat the recording layer to a recordable temperature. Therefore, if the film thickness of Al of the reflective layer becomes smaller toward the outer peripheral side, the change in laser power between the inner peripheral side and the outer peripheral side can be reduced. Even in this case, the openings do not necessarily have to be continuous, as shown in FIG.
It may be divided into a plurality of opening regions as in (a) and (b).

The smaller the thickness of the second dielectric protective layer having a smaller thermal conductivity than that of the metal film, for example, SiO ₂ or SiO, the larger the heat loss due to the heat conduction to the reflective layer.
The laser power required to heat the recording layer to a recordable temperature increases. Therefore, as the second dielectric protective layer, for example, the first film thickness correcting mask 27a is used as the vacuum chamber 3
4 and, instead, the second mask 27b for film thickness correction is introduced into the vacuum chamber 33, and SiO ₂ is formed so that the film thickness becomes larger toward the air side. The change in the laser power during the period can be reduced.

At this time, sputtering is performed by using Si or SiO ₂ as a target and Ar and O ₂ as introduced gases. Although FIG. 8 shows an example of DC bipolar sputtering, it is of course possible to use RF sputtering or magnetron sputtering. Further, for example, when forming a magnetic layer of a Tb, Fe, Co-based alloy, a magnetic layer is formed by using a Tb, Fe, Co-based alloy target without using a film thickness correction mask. Layers can be deposited uniformly,
It is possible to manufacture a stable magneto-optical recording medium in which the life of the magnetic layer does not vary depending on the position on the substrate. Further, in the present invention, since the film thickness correction mask can be taken out and replaced without exposing the film forming vacuum tank to the atmosphere, it is possible to evaporate substances while keeping the film forming vacuum tank clean. It is possible to replace the dirty mask with a new mask, and it is possible to manufacture a magneto-optical recording medium having stable characteristics.

As described above, in the magneto-optical recording medium manufacturing apparatus according to the second aspect, the sputtering vacuum chamber 33, the auxiliary vacuum chamber 34, the plurality of targets 25, and the plurality of disk-shaped substrates facing the target source. A substrate holder 22 for holding 21 is provided, and the film thickness is continuously or stepwise changed between the target 25 and the substrate 21 in the radial direction of the substrate. Also the first film thickness correction mask 27a for correcting the distribution so that the film thickness becomes smaller, or the second film thickness correction mask set so that the film thickness on the outer peripheral side is larger than that on the inner peripheral side. It is possible to arrange 27b. Moreover, the mask for film thickness correction can be moved between the vacuum chamber 33 for sputtering and the auxiliary vacuum chamber 34 as needed. Further, when the masks are introduced into the vacuum chamber 33 for sputtering, the film thickness correction masks are fixed so that the centers of the film thickness correction masks and the substrate can be defined so as to be coaxial with each other. Stopper 2 for
7c is provided in the vacuum chamber for sputtering. Also,
A film thickness uniformizing mask 31 corresponding to each target 25 is arranged between the target 25 and the film thickness correcting mask.

The substrate 21 can be rotated in-plane by the rotation introducing machine 23. Further, the film thickness uniformizing mask 31 can be rotated in-plane by the rotation introducing device 30. The center of the film thickness correction mask and the center of the substrate are coaxial, and the center of the film thickness uniforming mask and the center of particle distribution from the target are coaxial.

Further, it has a power supply means for sputtering, and an active or inactive gas or a mixed gas of both is introduced into the vacuum chamber. Either DC sputtering or RF sputtering may be used as the sputtering method. If the in-plane distribution of sputtered particles is rotationally symmetric, the magnetron sputtering method may be used. The particles forming the sputtered target have a uniform in-plane distribution when passing through the mask for uniform film thickness, and the desired in-plane distribution when passing through the mask for correcting film thickness. Fixed to fly to the side of the board. When the first film thickness correcting mask is used, the film thickness is continuously or stepwise changed in the radial direction of the substrate by setting the opening of the film thickness correcting mask, and the outer peripheral side is inward at this time. The distribution is modified so that the film thickness is smaller than on the peripheral side. At this time, at least one of the film thickness correction mask and the substrate holder is rotated in the plane, and the film thickness uniforming mask is rotated in the plane. Therefore, the film thickness correcting mask and the film thickness uniforming mask are rotated. Does not produce a shadow. When the second film thickness correction mask is used, the opening of the film thickness correction mask for correcting the in-plane distribution of the particles from the target is such that the film thickness is continuous or continuous in the radial direction of the substrate. The thickness is changed stepwise, and at that time, the film thickness is set to be larger on the outer peripheral side than on the inner peripheral side.

FIG. 15 is a view showing still another embodiment of the magneto-optical recording medium manufacturing apparatus according to the present invention. In the figure, 41 is a substrate, 42 is a substrate holder, 43 is a rotation introducing machine, and 44 is a support. Electrodes, 45 is an evaporation source, 46 is a support, 47a is a first mask for correcting film thickness, 47b is a mask for correcting second film thickness,
47c is a stopper, 48a and 48b are power supplies, 49 is also a support / electrode, 50 is a rotation introducing machine, 51 is a mask for uniform film thickness, 52 is a guide rail, 53 and 54 are vacuum chambers, 5
Reference numeral 5 is a gate valve. The vacuum chamber 53 and the vacuum chamber 54 are connected via a gate valve 55. The substrate 41 can rotate in-plane by the rotation introducing device 43. Between the pair of support / electrodes 44 is a resistance heating evaporation source 45.
I support you. Instead of such an evaporation source, an evaporation source used in a conventional vacuum evaporation deposition method such as a beam evaporation source can be used as appropriate. At this time, the distribution of the vaporized particles can be considered to be sufficiently rotationally symmetric at the position of incidence on the mask for uniforming the film thickness.

The first film thickness correcting mask 47a and the second film thickness correcting mask 47b are usually inside the auxiliary vacuum chamber 54, and by moving along the guide rails 52 as necessary, inside the vacuum chamber 53. Will be introduced to. At this time, the shape of the film thickness correction mask has an opening 56 and a tapered portion 57 as shown in FIGS. 16 (a) and 16 (b). There is a stopper 47c having a shape corresponding to the tapered portion of the mask, and the film thickness correcting mask is fixed in a state where the position is defined so that the center of the film thickness correcting mask and the center of the substrate are finally coaxial. Further, the film thickness uniformizing mask 51 is supported by the support 49, and is arranged closer to the evaporation source side than the film thickness correcting mask. Further, the film thickness uniforming mask 51 is rotated in-plane by the rotation introducing machine 50. With this, even if the substrate and the mask for correcting the film thickness are not necessarily arranged immediately above the target, the film thickness distribution can be set to a predetermined distribution, and it is possible to simultaneously form films on a plurality of substrates. ..

FIG. 17 is a view showing the mask 51 for uniforming the film thickness, and the hatched portion in the drawing shows the shielding portion. γ (r) = a / f (r) γ: Sum of opening angles at a distance r from the mask center f (r): Distribution of vaporized substances incident on the mask for uniform film thickness (calculated value or measured value) a : Positive constant and opening angle are set. Here, in order to stabilize the discharge, the opening may have a mesh shape.

As shown in FIG. 18, the opening of the first film thickness correcting mask has an opening angle of, for example, γ '(r) =-b * r + d γ': distance from the mask center b, d: positive It is set to be a constant, and after the evaporative substance has passed, the in-plane distribution is corrected so that the film thickness on the outer peripheral side is smaller than that on the inner peripheral side. The openings need not necessarily be continuous and may be divided into a plurality of opening areas as shown in FIGS. 19 (a) and 19 (b).

FIG. 20 shows a second film thickness correcting mask, the opening angle of which is γ ″ (r) = c · r + e γ ″: the sum of the opening angles at a distance r from the mask center c, e : It is a positive constant. Also in this case, the openings need not necessarily be continuous and may be divided into a plurality of opening regions as shown in FIGS. 21 (a) and 21 (b).

The electrode also serving as a support 44 is a conductor and also serves as an electrode, and the ends of these electrodes protruding outside the vacuum chamber are connected to a power source 48a as shown in the figure. The support / electrode 49 is also a conductor and also serves as an electrode, and the end portions thereof protruding outside the vacuum chamber are connected to the negative terminal of the power source 48b as shown in the figure.
Further, the positive terminal of the power source 48b is connected to the support / electrode 44. The grounding in the figure is not always necessary. Actually, these electrical connections include various switches, and these operations realize the film forming process.
These switches are not shown in the figure.

The method of manufacturing the magneto-optical recording medium according to the third embodiment will be described below. The substrate 41 is set on the substrate holder 42 as shown in FIG.
To hold. The base material forming the evaporation material is determined according to what kind of thin film is formed. For example, as the reflective layer A
When 1 is used, metal Al is used as a base material, and when Cr is used, metal Cr is used as a base material. Here, for the sake of explanation, the reflective layer is an Al film.

First, the first film thickness correction mask 47a is moved to the vacuum chamber 53, and the film thickness correction mask is stopped by the stopper 47.
Fix at c. In the present embodiment, the film thickness correction mask and the stopper are formed in a tapered shape with unevenness. At this time,
The second film thickness correction mask 47b is inside the vacuum chamber 54. The pressure in the vacuum chamber is set to 10 ⁻⁵ to 10 ⁻⁶ Torr in advance, and then Ar gas is introduced to a pressure of 10 ⁻² Torr.
In this state, the power source 48b is operated to generate a DC discharge between the evaporation source 45 and the film thickness uniforming mask.
Further, the power source 48a is operated to heat the evaporation source 45 to evaporate the evaporation material. At this time, a part of the vaporized material is ionized by the electrons generated by the discharge and flies toward the film thickness correction mask 47a together with the non-ionized vaporized material and Ar ions, but the opening angle is set as described above. The in-plane distribution is made uniform when passing through the formed film thickness uniformizing mask 51, further corrected to a desired distribution by the film thickness correcting mask, and then the film is flown to the substrate 41 side. The adhesion of the Al film to the substrate is improved by using the ion plating method. In the first film thickness correcting mask 47a, the film thickness is continuously or stepwise changed in the radial direction of the substrate, and the film is formed so that the film thickness on the outer peripheral side is smaller than that on the inner peripheral side. To do.

The thicker the Al film thickness of the reflective layer, the greater the thermal diffusion due to heat conduction, and the greater the laser power required to heat the recording layer to a recordable temperature. Therefore, if the film thickness of Al of the reflective layer becomes smaller toward the outer peripheral side, the change in laser power between the inner peripheral side and the outer peripheral side can be reduced. Also in this case, the opening does not necessarily have to be continuous and may be divided into a plurality of opening regions as shown in FIG.

The smaller the thickness of the second dielectric protective layer having a smaller thermal conductivity than that of the metal film, for example, SiO ₂ or SiO, the larger the heat loss due to the heat conduction to the reflective layer.
The laser power required to heat the recording layer to a recordable temperature increases. Therefore, as the second dielectric protection layer, for example, the first film thickness correction mask 47a is moved to the vacuum chamber 54, and instead, the second film thickness correction mask 47b is used.
Is introduced into the vacuum chamber 53, and SiO ₂ is formed so that the film thickness increases toward the outer peripheral side, the change in the laser power between the inner peripheral side and the outer peripheral side can be reduced. At this time, ion plating is performed by using Si or SiO ₂ as an evaporation material and Ar and O ₂ as introduction gases.
Although FIG. 15 shows an example of DC ion plating, it is of course possible to use RF ion plating. In FIG. 15, a mask 51 for uniform film thickness
Has a positive potential with respect to the substrate holder 42, but may have the same potential.

Further, for example, when forming a magnetic layer of Tb, Fe, Co alloy, in Ar gas from each Tb, Fe, Co metal evaporation source without interposing a mask for film thickness correction. By ion plating, a magnetic layer can be formed uniformly, and a stable magneto-optical recording medium can be manufactured in which the life of the magnetic layer does not vary depending on the position on the substrate. Further, in the present invention, since the film thickness correction mask can be taken out and replaced without exposing the film forming vacuum tank to the atmosphere, it is possible to evaporate substances while keeping the film forming vacuum tank clean. It is possible to replace the dirty mask with a new mask, and it is possible to manufacture a magneto-optical recording medium having stable characteristics.

As described above, in the magneto-optical recording medium manufacturing apparatus of the third aspect, the ion plating vacuum chamber 53, the auxiliary vacuum chamber 54, the plurality of evaporation sources 45, and a plurality of evaporation sources 45 facing each other are provided. A substrate holder 42 for holding the disc-shaped substrate 41, and the film thickness between the evaporation source 45 and the substrate 41 is changed continuously or stepwise in the radial direction of the substrate, and at this time, the outer peripheral side Is set to a first film thickness correcting mask 47a for correcting the distribution so that the film thickness is smaller than that on the inner circumference side, or the film thickness on the outer circumference side is larger than that on the inner circumference side. It is possible to dispose the second film thickness correction mask 47b. In addition, the mask for film thickness correction can be moved between the vacuum tank 53 for vacuum deposition and the auxiliary vacuum tank 54 as needed. Further, when the masks are introduced into the vacuum chamber 53 for vacuum deposition, the masks for film thickness correction are set so that the center of the film thickness correction mask and the center of the substrate can be located coaxially. A stopper 47c for fixing is provided in the ion plating vacuum chamber. Further, a film thickness uniformizing mask 51 corresponding to each evaporation source 45 is arranged between the evaporation source 45 and the film thickness correction mask.

The substrate can be rotated in-plane by the rotation introducing device 43. Further, the film thickness uniformizing mask can be rotated in-plane by the rotation introducing machine 50. The center of the film thickness correction mask and the center of the substrate are coaxial, and the center of the film thickness uniforming mask and the center of the evaporation distribution are coaxial. Further, it has a power supply means for ion plating, and an active or inactive gas or a mixed gas of both of them is introduced into the vacuum chamber. As the ion plating method, either DC ion plating or RF ion plating may be used. At this time, a power supply means is connected between the film thickness uniforming mask and the evaporation source so as to generate a discharge, and the film thickness correcting mask has a positive potential or the same potential with respect to the substrate holder.

The in-plane distribution of the evaporation material from the evaporation source is made uniform when passing through the mask for uniforming the film thickness, and the in-plane distribution is aimed at when passing through the mask for correcting film thickness. Fixed to fly to the side of the board. When the first film thickness correcting mask is used, the film thickness is continuously or stepwise changed in the radial direction of the substrate by setting the opening of the film thickness correcting mask, and the outer peripheral side is the inner peripheral side at that time. The distribution is modified so that the film thickness is smaller than on the side. At this time,
At least one of the film thickness correction mask and the substrate holder rotates in the plane, and the film thickness uniforming mask rotates in the plane. Therefore, the shadows of the film thickness correction mask and the film thickness uniforming mask are Does not happen. When the second mask for correcting film thickness is used, the opening changes the film thickness continuously or stepwise in the radial direction of the substrate, in which case the outer peripheral side has a larger film thickness than the inner peripheral side. Is set.

[0048]

As is apparent from the above description, according to the magneto-optical recording medium manufacturing apparatus of the present invention, the film thickness of the film forming the magneto-optical disk is continuously increased in the radial direction from the inner peripheral side to the outer peripheral side. Or because it can be changed in stages,
It is possible to provide a method of manufacturing a magneto-optical disk in which the magneto-optical disk is rotated at a constant rotation speed, in which a change in laser light intensity required for recording is small in a so-called CAV method. Therefore, by using the present invention, the load on the drive side can be reduced. Further, restrictions on the position of the evaporation source or the target with respect to the substrate can be reduced, and film formation can be performed on a plurality of substrates at the same time, which improves productivity. Further, according to the present invention, since the film thickness correction mask can be taken out and replaced without exposing the film forming vacuum tank to the atmosphere, the film forming vacuum tank can be replaced with an evaporated substance while keeping the film forming vacuum tank clean. A dirty mask can be replaced with a new mask, and a magneto-optical recording medium having stable characteristics can be manufactured.

[Brief description of drawings]

FIG. 1 is a configuration diagram for explaining an embodiment of a magneto-optical recording medium manufacturing apparatus according to the present invention.

FIG. 2 is a diagram showing a shape of a film thickness correction mask.

FIG. 3 is a diagram showing the shape of a mask for uniforming the film thickness.

FIG. 4 is a diagram showing an opening of a first film thickness correction mask.

FIG. 5 is a diagram showing an opening portion divided into a plurality of opening regions of the first film thickness correction mask.

FIG. 6 is a diagram showing an opening of a second film thickness correction mask.

FIG. 7 is a diagram showing an opening portion divided into a plurality of opening regions of a second film thickness correction mask.

FIG. 8 is a diagram showing another embodiment of the magneto-optical recording medium manufacturing apparatus according to the present invention.

FIG. 9 is a diagram showing a shape of a film thickness correction mask.

FIG. 10 is a diagram showing the shape of a mask for uniforming the film thickness.

FIG. 11 is a diagram showing an opening of the first film thickness correction mask.

FIG. 12 is a diagram showing an opening portion divided into a plurality of opening regions of the first film thickness correction mask.

FIG. 13 is a diagram showing an opening of a second film thickness correction mask.

FIG. 14 is a diagram showing openings divided into a plurality of opening regions of a second film thickness correction mask.

FIG. 15 is a diagram showing still another embodiment of the magneto-optical recording medium manufacturing apparatus according to the present invention.

FIG. 16 is a diagram showing a shape of a film thickness correction mask.

FIG. 17 is a diagram showing the shape of a mask for uniforming the film thickness.

FIG. 18 is a diagram showing an opening of the first film thickness correction mask.

FIG. 19 is a diagram showing openings divided into a plurality of opening regions of the first film thickness correction mask.

FIG. 20 is a diagram showing an opening of a second film thickness correction mask.

FIG. 21 is a diagram showing an opening portion divided into a plurality of opening regions of the second film thickness correction mask.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Substrate, 2 ... Substrate holder, 3 ... Rotation introduction machine, 4 ... Electrode also serving as a support, 5 ... Evaporation source, 6 ... Support, 7a ... First mask for correcting film thickness, 7b ... For correcting second film thickness Mask, 7c ... stopper, 8 ... electrode, 9 ... support, 10 ... rotation introducing machine,
11 ... Mask for uniform film thickness, 12 ... Guide rail, 1
3, 14 ... Vacuum tank, 15 ... Gate valve.

Claims (3)

[Claims] 1. A vacuum tank for vacuum vapor deposition, a plurality of evaporation sources, a substrate holder that faces the evaporation sources and holds a plurality of disk-shaped substrates, and between the evaporation source and the substrate holder. Firstly, the openings are arranged so that the film thickness is continuously or stepwise changed in the radial direction of the substrate, and at that time, the film thickness on the outer peripheral side is smaller than that on the inner peripheral side. A film thickness correction mask, a second film thickness correction mask having an opening so that the film thickness on the outer peripheral side is larger than that on the inner peripheral side, and the film thickness correction connected to the vacuum chamber. Auxiliary vacuum chamber for housing and replacement of the mask for use with the mask, and defining means for defining the positional relationship between the first and second masks for film thickness correction and the substrate,
Moving means for moving the first and second film thickness correction masks between the two vacuum chambers, and the evaporation sources on the evaporation source side of the first and second film thickness correction masks correspond to the respective evaporation sources. A magneto-optical recording medium comprising a mask for uniform film thickness arranged in such a manner that the mask for uniform film thickness is rotated in-plane and the substrate is vacuum-deposited while rotating in-plane. Manufacturing equipment. 2. A vacuum chamber for sputtering, a plurality of targets, a substrate holder that faces the targets and holds a disk-shaped substrate, and is disposed between the targets and the substrate holder, and has a film thickness of A first film thickness correcting mask in which the opening is set such that the film thickness is changed continuously or stepwise in the radial direction of the substrate, and the film thickness on the outer peripheral side is smaller than that on the inner peripheral side at that time. A second mask for correcting film thickness in which an opening is set so that the film thickness on the outer peripheral side is larger than that on the inner peripheral side, and an auxiliary for storing and replacing the mask holder connected to the vacuum chamber A vacuum chamber, a defining means for defining the positional relationship between the first and second film thickness correction masks and the substrate, and a target side of the film thickness correction masks arranged so as to correspond to the targets. And a mask for uniformizing the film thickness. An apparatus for manufacturing a magneto-optical recording medium, wherein a film for sputtering is formed while rotating a mask for unifying in a plane and rotating the substrate in a plane. 3. A vacuum tank for ion plating, a plurality of evaporation sources, a substrate holder that holds a disk-shaped substrate facing the evaporation sources, and is arranged between the evaporation source and the substrate holder. The film thickness is continuously or stepwise changed in the radial direction of the substrate, and the opening is set so that the film thickness on the outer peripheral side is smaller than that on the inner peripheral side. A correction mask, a second film thickness correction mask in which an opening is set so that the film thickness on the outer peripheral side is larger than that on the inner peripheral side, and the film thickness correcting mask connected to the vacuum chamber. An auxiliary vacuum chamber for accommodating and replacing the film, and defining means for defining a positional relationship between the first and second film thickness correcting masks and the substrate,
A moving unit that moves the first and second film thickness correction masks between the two vacuum chambers, and an evaporation source that corresponds to each evaporation source rather than the first and second film thickness correction masks. A magneto-optical recording medium, comprising: a film thickness uniformizing mask disposed on the substrate, wherein the film thickness uniformizing mask is rotated in-plane and the substrate is ion-plated while rotating in-plane. Manufacturing equipment.