JPH02277768A - Sputtering method - Google Patents

Abstract

PURPOSE:To form a magnetic recording layer having uniform film thickness distribution and composition ratio by disposing a fist sputtering target in a position between second two tilted sputtering targets and alternately performing the electric discharge of the first sputtering target and the electric discharge of the second sputtering targets while the substrate is passed through a film forming resion. CONSTITUTION:A magneto-optical recording layer consisting of a first thin metallic film and a second thin metallic film dissimilar to each other is formed on a substrate 11. Second rectangular sputtering targets 2a, 2b consisting of a second metal are tiltedly disposed in a manner to be opposed to each other along the traveling direction of the substrate 11 in the positions where a first rectangular sputtering target 1 consisting of a fist metal is interposed between the above second sputtering targets 2a, 2b. Then, respective electric discharges of the first sputtering target 1 and the second sputtering targets 2a, 2b are alternately performed at least while the substrate 11 is passed through a film forming region. By this method, a high-quality magneto-optical recording medium excellent in magneto-optical characteristics can be provided.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a sputtering method, and particularly to a sputtering method in which a thin film is formed by continuous sputtering on a continuously transferred substrate.

(Prior art) In recent years, magneto-optical recording media have been developed using laser beam writing,
It is used as a readable magneto-optical disk for large-capacity data files. This magneto-optical disk is made by sputtering a dielectric layer onto a transparent substrate such as glass or plastic. It has a layered structure including two layers and a protective layer. The recording layer exhibiting the magneto-optical effect is made of a mixed or laminated thin film of a rare earth metal (hereinafter referred to as rRE metal) and a transition metal (hereinafter referred to as ``TM gold metal'').

Next, a sputtering method for forming a thin film will be briefly explained. Sputtering technology generates a glow discharge using an inert gas such as Ar gas in a low-pressure atmosphere, and causes ions in the plasma to collide with a cathode target.
This is a technology in which atoms are ejected from a target material to form a thin film on a substrate placed to face the target, and is widely used industrially. The magnetron sputtering method, which is characterized by forming an electric field and a magnetic field orthogonal to each other, has a high film formation rate and has the effect of suppressing the temperature rise of the sputtering substrate, making it a very useful method for magnetic recording media and It is widely used in the semiconductor manufacturing process.

In addition, it is known that the performance of the magnetic recording layer is higher when the magnetic recording layer has a laminated structure in which RE gold metal TM gold metal is alternately laminated than an alloy in which RE gold metal TM gold metal is mixed. It is being

Regarding the sputtering method for forming the magnetic recording layer of the laminated structure in the conventional magneto-optical recording medium, for example,
Although various disclosures are made in JP-A-61-77155, JP-A-62-60865, JP-A-62-71041, etc., the basic structure of the apparatus used in the method shown in the above-mentioned publications is shown in Figs. 5 and 6. I will explain based on this. FIG. 5 shows a sputtering apparatus called a rotational film forming apparatus. A magnetron sputtering cathode 100 provided on the lower side of a vacuum chamber 103 in the figure has a permanent magnet 1 on its back side, for example.
02, circular target plates T-101a and 101b made of RE gold metal T and M metal respectively are sputtering power sources.
04a and 104b and are arranged at a predetermined interval. A substrate 105 is fixed to a revolving substrate holder 106 located opposite the targets 101a and 101b, and rotates approximately at the center of the targets 101a and 101b. As the revolving substrate holder 106 revolves around '+b 108, RE gold metal and TM gold metal are alternately deposited on the substrate to form a laminated thin film. In this apparatus, the structural change of the recording layer can be controlled by the rotational speed of the revolving substrate holder 106 and the power ratio applied to each target 101a, 101b. In order to obtain improved characteristics of magnetization, coercive force, and magneto-optical effect (Kerr effect), the laminated structure of the RE metal layer and TM metal layer can be changed to a certain extent, so it is relatively easy to control. Although it is possible to form a medium, there is a limit to increasing the rotational speed, and there is a limit to making each layer thinner.

Also, based on the research results so far, high quality optical G! In order to obtain an air disk, the film thickness distribution must be within ±5%, preferably within ±3%.

However, in general, in a film forming apparatus that simply revolves and does not have a film thickness distribution correction plate 107, etc., the film thickness distribution of the recording layer on a circular substrate becomes large, so that it cannot be used as a magneto-optical disk. When the dynamic characteristics are evaluated, the disadvantage is that the C/N and envelope characteristics in the disk circumferential direction, that is, carrier signal fluctuations in the disk circumferential direction tend to be large and unsatisfactory. Therefore, conventionally, as shown in FIG. 5, in addition to the substrate revolving structure, a film thickness distribution correcting plate 107 is installed to perform film thickness correction. On the other hand, as another method, in addition to the substrate revolving holder 106, as in the device shown in FIG.
3 etc., the substrate 105 can rotate around its axis. However, the former method shown in FIG. 5 is based on the influence of dust generated due to falling off of the film deposited on the film thickness distribution correction plate 107 (including other masking having an appropriate opening shape). There was a problem in that pinholes were formed on the film-forming surface. Further, although the latter method shown in FIG. 6 does not require the use of the film thickness distribution correction plate 107, it has the disadvantage that the rotation and revolution mechanism becomes complicated. Furthermore, the biggest problem with the entire rotational film deposition method is that not only can we not expect much from thinning each layer due to the rotational speed of the substrate revolving holder 106, but also each layer of the dielectric layer, protective layer, recording layer, etc. Since the film formation is performed in separate film formation chambers, steps such as transferring the substrate holder between chambers and chucking the rotation shaft of the substrate holder to a rotating means are required.

This was the most important problem in terms of cost, as the substrate transport, which is not directly involved in film formation, and the centration time for film formation preparation were large, preventing productivity from increasing.

In order to solve the problems of the above-mentioned pallet rotation type sputtering apparatus, a substrate passing type sputtering apparatus as shown in FIG. 7 has been proposed for the purpose of improving productivity. This device consists of an alloy target 123 consisting of RE gold metal TM gold metal intermetallic compound c (hereinafter referred to as IMC).
(or an alloy target consisting of three elements of RE Gold Metal TM Gold Metal IMC) is connected to the sputtering chamber a130,
A rectangular sputtering cathode 122 having a permanent magnet 124 on the back side is provided, and a substrate 125 is moved at a constant speed in a direction perpendicular to the longitudinal direction of the target 123 (in the direction of six arrows), facing the target surface. , an apparatus for forming a recording layer made of the target material. In this apparatus, normally two to three substrates 125 are placed in parallel on the substrate holder 121 in a direction transverse to the direction of movement of the substrates 125, and are continuously moved for film formation, thereby greatly improving productivity. The disadvantages of this substrate passing type sputtering apparatus are mainly due to the characteristics of the alloy target 123. That is,
When forming an alloy thin film using the alloy target 123, the emission angle distribution of target elements (sputtered particles) toward the substrate by the alloy target 123 differs depending on each element. For example, when examining the composition ratio of the constituent elements of the thin film for each sample with respect to samples attached to a plurality of substrates placed in a stationary state facing the alloy target 123, it is found that the center of the target 123 For the sample located at the position facing the target 123, the RE gold metal percentage tends to be high, and for the sample located at the position facing the outer part of the target 123, the RE gold metal ratio tends to decrease from the center to the outside.

Therefore, in the substrate passing type sputtering apparatus using the alloy target 123, the substrate 125 forms a thin film while moving in a direction perpendicular to the longitudinal direction of the alloy target 123, so that at the start of film formation, (at the position on the left side of the sputtering chamber in the figure), the RE gold metal adhesion ratio is low, and then at the position facing the central part of the alloy target 123, the RE gold metal ratio increases,
Thereafter, there will be a slight change in the composition along the line through which the substrate 125 passes until the film forming process is completed, such that the RE gold metal proportion will decrease at a position on the right side of the sputtering chamber. If the rate of this compositional change is large, a characteristic problem of C/N deterioration occurs. moreover,
Another major drawback of the alloy target 123 is that the composition ratio gradually changes as the target 7) is used for a long time, shortening the life of the alloy target 123 and increasing the cost of the product. However, it was not possible to form a TM gold metal laminated thin film, and there was a limit to the performance improvement of magnetic recording media.

The problem of the emission angle distribution of sputtered particles of an alloy target, which is a drawback of the substrate passing type sputtering apparatus,
In addition, as a film forming method that solves the problem of composition deviation during long-term use, the present applicant has previously filed a patent application filed in 1986-2.
No. 48876 was proposed. This uses R as a target.
Using separate single pieces of E gold metal and TM gold metal, one TM
This is a method in which the RE gold metal targets are positioned on both sides of the gold metal target, and the RE gold metal targets are tilted to face each other in order to further make the film thickness distribution uniform.

The present inventors have proposed a magneto-optical recording medium with even better cylindrical quality based on the method disclosed in Japanese Patent Application No. 62-248876. It has become clear that the positional relationship between the substrate and each target, the dimensional relationship in the moving direction, the inclination angle of the tilted target, etc. affect the film thickness distribution and composition distribution in a certain lawful relationship. ing.

However, although various proposals have been made in the past and the performance of magneto-optical disks has improved, a method for producing a laminated thin film magnetic recording layer well and extremely efficiently has not yet been developed. This was a major issue.

(Objective of the Invention) The object of the present invention is to provide a magnetic recording layer having a laminated structure in which RE gold metal TM gold metal is alternately laminated, to have a uniform thickness distribution and a uniform composition ratio, and to have C/N and envelope characteristics. It is an object of the present invention to provide a sputtering method which is excellent in film formation rate, can be formed at a high film formation rate, can realize high quality magnetic recording media, and can realize low manufacturing costs.

(Structure of the Invention) An object of the present invention is to extend a plurality of rectangular sputtering targets in a long shape in a direction perpendicular to the transfer direction of a substrate, which is an object to be film-formed, to face each other. In a substrate passing sputtering method for forming a magneto-optical recording layer made of thin films of at least first and second different metals, the first sputtering target is placed at a position sandwiching a rectangular first sputtering target made of the first metal. rectangular second sputtering targets made of two metals are arranged in parallel so as to be inclined to face each other along the substrate traveling direction, and the first sputtering targets are arranged in parallel so as to face each other along the substrate traveling direction, and at least while the substrate passes through the film forming region, the first sputtering target This can be achieved by a spattering method characterized in that the magneto-optical recording layer is composed of a laminated thin film by alternately performing Kuge-nod discharge and discharge of the second sputtering target. . Furthermore, the discharge of the first sputtering target nod and the discharge of the second sputtering target are performed based on the frequency and waveform of a signal generated by an arbitrary waveform generator, and the frequency is set in the film forming region. The thickness of each layer of the laminated thin film can be controlled by controlling it in accordance with the change in the film formation rate of the substrate position within the layer.

Embodiments of the present invention illustrated in the drawings will be described in detail below.

(Embodiment) FIG. 1 shows a schematic diagram of a sputtering apparatus for carrying out the method of the present invention.

In the sputtering apparatus according to the present invention, a plurality of vacuum chambers each having an independent exhaust system 17 are partitioned by a gate valve 18 so as to be able to communicate with each other, and a desired thin film is formed in continuous sputtering chambers 19, 20, and 21. It is now possible to do so. The plurality of substrate holders 13 guided by the transport rolls 14 forming a transport path are
It is configured to be continuously transported into the sputtering chamber I9.20.21 at a constant speed. In addition, on the lower side of the main body of the substrate holder 13, circular glass or plastic substrates 11 (not shown, but a plurality of substrates are provided in a direction perpendicular to the conveyance direction) are appropriately controlled by a substrate mask 12. Retained.

Although not shown, the substrate 11 may be held by a rotatable turntable. In this case, a rotating shaft is provided at the center of the turntable, and the rotating shaft is aligned with the substrate holder I3. The structure may be such that the pinion extends upward through the main body and engages with the rack fixed to the sub-interchamber 19, 20, 21 near the upper end of the rotating shaft. Depending on the structure,
By moving the substrate holder 13 along the transport roll 14, the turntable can also be rotated in a predetermined direction.

At the bottom side of the sputtering chamber 20, a central cathode 3 and both end cathodes 4a, 4b on both sides of the central cathode 3 are provided.
For example, at positions sandwiching a rectangular first sputtering target 1 made of RE gold metal, the same (rectangular second sputtering targets 2a and 2b made of TM gold metal) are placed in the substrate running direction (in the direction of the arrow). The first sputtering target 1 and the two second sputtering targets 2a and 2b are arranged in parallel along the same direction.
Permanent magnets 5.6a and 6b are installed on the back side of each target to generate a leakage magnetic field on the surface of each target, and an earth shield 15.16 is also installed in a suitable position to prevent abnormal discharge from occurring between both targets. .

Further, the both end cathodes 4a, 4b are positioned at an angle so as to face each other, and are located between the sputtering plane of the first sputtering target 1 and the respective sputtering planes of the second sputtering targets 2a, 2b. The structure is such that the angle .alpha. formed can be fixed and held at an arbitrary angle. Incidentally, the both end cathodes 4a, 4
The holding structure b is a well-known structure such as bolt tightening, so it is omitted in FIG. 1.

The relationship between the length a of the short side of the first sputtering target 1 along the substrate running direction and the length b of the short side of the second sputtering targets 2a and 2b along the substrate running direction is, for example, 0. , 6≦a/b≦2.0. Also, the relationship between the distance i%ILts between the surface of the first sputtering target 1 and the substrate 11 and the length b of the short side of the second sputtering targets 2a and 2b along the substrate running direction. However, it is desirable to be configured such that it can be set within a range of approximately 1.0≦Lts/b≦2°0.

Cooling channels 7.8a, 8b are formed inside the permanent magnets 5.6a, 6b to adjust target temperature, and each of the rectangular sputtering targets 1.
2a and 2b have sputtering power supplies 9.10-a and 1, respectively.
0b is connected.

Further, although not provided in the apparatus shown in FIG. 1, for example, above the first sputtering target 1, there is provided an angle of incidence on the plastic substrate 11 of the sputtered particles evaporated from each sputtering target 1.2a, 2b. It is also possible to arrange regulating members forming slits for regulating the sputtering chamber 20 at both left and right ends of the sputtering chamber 20.

An inert gas such as argon (Ar) gas is introduced into the sputtering chamber 20 of the sputtering apparatus configured as described above from a gas inlet (not shown), and the sputtering target 1 and the sputtering target 2 are
Appropriate sputtering power may be applied alternately to a and 2b, or sputtering power and - may be applied to the substrate holder 1.
Set the transfer timing so that it can be started at the same time as step 3. Then, the substrate 11 on which a dielectric layer has been formed in advance is mounted on the substrate holder 13, and the plurality of substrate holders 13 on which the substrates 11 are mounted are successively transferred to the sputtering chamber 20, and the plastic R on the board 11
E Gold Metal TM A laminated thin film in which gold metals are alternately and repeatedly overlapped is formed.

In order to apply sputtering power alternately to the sputtering target 1 and the sputtering targets 2a and 2b, a current is applied at regular intervals to the sputtering power supply 9 of the sputtering target 1 and the sputtering power supplies 10a and 10b of the sputtering targets 2a and 2b. Make it inverted.

As shown in FIG. 2, while the arbitrary waveform generator 23a is connected to the sputter power source 9,
Arbitrary waveform generators 23b are also connected to 0a and LOb, and each arbitrary waveform generator 23a is controlled by a control means 24 such as a microcomputer.
, 23b.

Control by the arbitrary waveform generators 23a and 23b is performed using, for example, a sine wave as shown in FIG. 3, and the sputter power source 9 (A in FIG. 3) and the sputter power source 10a,
b (B in FIG. 3), for example, in the XrJ region in the figure, the sputtering target 1 does not discharge, and the sputtering device targets 2a and 2b discharge. Then, a TM gold metal thin film is formed on the substrate 11, and in the Y region, conversely, the sputtering target 1 is discharged to form an RE gold metal thin film. That is, discharge can be generated alternately between the sputtering target 1 and the sputtering targets 2a and 2b.

To explain in more detail the formation of a laminated thin film with RE gold and 7M metal by the sputtering method described above, first, the substrate holder 13 is placed in the sputtering chamber 20, which is maintained in a state desirable for desired sputtering, at a predetermined speed. It will be transported by. In the initial state when the substrate holder 13 enters the sputtering chamber 20 (the left side position in the figure), the second sputtering machine is tilted and adjusted appropriately so that it initially faces the left direction. Getsu 1-
7M metal sputtered particles scattered from 2b and the first
Alternate laminated films of both metals begin to adhere to the substrate 11 due to the RE gold metal sputter particles scattered from the sputtering target l. Thereafter, as the substrate holder 13 moves, the second sputtering target) 2b
The number of 7M metal sputtered particles flying out from the second sputtering target 2a on the left side of the figure gradually increases to replace them. By doing so, it is possible to improve the uniformity of the thickness of the TM metal layer in the film-forming region.

As described above, according to the present invention, the plurality of plastic substrates 11 are held by the substrate holder 13 and sputtered while being continuously transferred, so that productivity can be improved and, moreover, thin films with a laminated structure can be formed. Can be easily formed.

Note that the waveforms generated by the arbitrary waveform generators 23a and 23b are not limited to sine waves as described above, but may be rectangular waves or other forms.

Further, the RE gold metal sputter particles scattered from the first sputtering target 1 are distributed at the center position C of the first sputtering target 1 (approximately the center position on the left and right in the figure in the sputtering chamber 20), as shown in the graph of FIG. ) Draw a curve G that has the largest number above. In addition, in the case of 7M metal, although not shown, the second sputtering target 2
Although it differs somewhat depending on the inclination angle α of a and 2b (the curve has two raised parts), the left and right ends of the curve tend to fall, similar to the curve G. Therefore, when the cycles of the arbitrary wave generators 23a and 23b are constant, the thickness of each stacked layer varies in accordance with the curve G. In order to eliminate this variation in the film thickness of each laminated layer and to average the film thickness of each layer, the frequency change according to the curve H shown by the broken line in the figure, which is opposite to the slope of the curve G, is applied to the arbitrary waveform. By controlling the power to be generated from the generators 23a and 23b, the thickness from the bottom layer to the top layer of each laminated layer can be averaged. In other words, the fact that it is possible to average the film thickness of each layer formed by stacking in this way means that when the substrate 11 passes through the film-forming region, taking into consideration the scattering characteristics of the RE gold metal sputtered particles, This means that by appropriately changing the frequency to change the discharge period, the thickness from the bottom layer to the top layer of each laminated layer can be changed freely.

Therefore, according to the present invention described above, since the thickness of each layer of the metal thin film formed on the substrate 11 can be freely controlled, the characteristics of the substrate 11 can be controlled, resulting in high quality with excellent magneto-optical characteristics. It is possible to provide a magneto-optical recording medium.

In the above embodiment, the substrate 11 is attached to a non-rotating type substrate holder 13, but if the substrate holder 13 is replaced with one that allows the substrate 11 to rotate as described above, It is possible to further improve the uniformity of membrane conditions and achieve higher performance in envelope properties. Furthermore, the rotational structure of the substrate holder 13 is not limited to a structure that only rotates on its axis; it is also possible to mount a plurality of substrates on the substrate holder and transfer the substrates while rotating or rotating around them to form a film. Needless to say, the effects can be expected.

Further, regulating means for regulating the angle of incidence of the sputtered particles onto the substrate II may be provided on the population side and the exit side of the sputtering chamber 20.

The device of the present invention is not limited to the above embodiments,
For example, the conveyance structure of the substrate holder 13 can of course be changed in various ways, and the magnetic field strength can be freely controlled by replacing the permanent magnets 5.6a and 6b with electromagnets.

Further, the first sputtering target 1 is made of 7M metal, and the second sputtering target 2a 2
b can also be composed of RE gold metal.

Furthermore, the present invention is not limited to magneto-optical recording media, but can also be applied to the formation of thin films with a laminated structure, such as optical disks and superlattice thin films.

〔Effect of the invention〕

As described above, in the sputtering method of the present invention, a plurality of plate-shaped sputtering targets are elongated and faced in a direction orthogonal to the transfer direction of the substrate, which is the object to be film-formed. Fewer on top (both first and second)
A substrate passing sputtering method for forming a magneto-optical recording layer made of thin films of different metals, in which a rectangular sputtering target made of the second metal is placed at a position sandwiching a rectangular first sputtering target made of the first metal. second sputtering targets are arranged in parallel so as to face each other along the substrate traveling direction, and at least while the substrate passes through the film forming region, the discharge of the first sputtering target and the second sputtering target are performed. By alternating with the discharge of Characteristics can be improved. Furthermore, since the target is made of a single material, the target has a long lifespan, and the recording layer of magneto-optical recording media with excellent characteristics can be formed for a long time at a high growth rate. It is possible to achieve high manufacturing costs and low manufacturing costs.

Furthermore, according to the sputtering method of the present invention, the discharge of the first sputtering target and the discharge of the second sputtering target are performed alternately based on the frequency of a signal generated by an arbitrary waveform generator, and can be controlled in response to changes in the deposition rate at the substrate position within the deposition region, so not only can the thickness of each laminated layer from the bottom layer to the top layer be averaged, but also the thickness of the substrate can be By appropriately changing the frequency to change the discharge cycle when passing through the film formation region, the thickness of each laminated layer from the bottom layer to the top layer can be freely changed to control the characteristics of the substrate. It is possible to provide a high-quality magneto-optical recording medium with excellent magneto-optical properties.

Hereinafter, the effects of the present invention can be further clarified through Examples.

Implementation Solitary.

In the sputtering apparatus shown in FIG. 1, Tb (width 89 mm x length 610 mm x thickness 5 mm) is attached to the first sputtering target 1 as a RE metal target, and Fezo, C as a 7M metal target is attached to the second sputtering targets 2a and 2b.

8°, (width 76 mm x length 610 mm x thickness 4 mm) was attached. Said second sputtering target 2a, 2
The inclination angle (α) of b was set to 50°. Each target has a target power source 9.10, which is a DC power source.
a, 10b, the maximum power supplied to the second sputtering targets 2a, 2b is 1,650 W, the maximum power is 800 W to the first sputtering target 1, and the ultimate pressure of the sputtering chamber is 5.
0×10-'Torr, Ar gas flow i 40 SCC
M, sputtering pressure 2. I set it to 2 Torr. In addition, the distance between the target and the substrate (Lts5 was set to 120 mm, the conveyance speed of the substrate holder was 130 mm/mjm, and the substrates were arranged perpendicularly to the conveyance direction to form three bases t7iA,
I installed B and C. In addition, each board A, B,
A plastic optical film St 3N4 having a diameter of φ13Q mm and a thickness (t) of 1.2 mm was formed in advance by 840 people.

Sputtering was performed twice in total with a plurality of plastic substrates uniformly placed on the substrate movement line at all positions where the substrates were moved.

The power control signal (A) of the sputter power source 9 and the power control signal (B) of the sputter power sources 10a and 10b are sine waves of 1. OHz, and the phase difference of the signal was controlled by π. The control system was as shown in FIG. 4, the film forming time was 120 seconds, and the film thickness was 960λ.

As a result of taking out this sample and measuring its characteristics, the film characteristics were as follows: a write power of 7 mW at R=30 mm (on the circumference 30 mm from the center of the disk).

Signal frequency 3.71MHz (carrier wave), rotation speed 180
The average value of the samples under the conditions of
．． 6 dB, and a magneto-optical disk with high characteristics could be obtained.

Comparative Example 1 A film was formed using a conventional rotary film forming apparatus shown in FIG.

In Fig. 5, a RE gold metal sputtering target with a diameter of 103 mm and a thickness of 5 m is placed inside the vacuum chamber 103.
m Tb target 101a and a 7M metal sputtering target with a diameter of 103 mm and a thickness of 4 mm FegoCOao target 101b with a center distance of 2
These targets 1
Opposed to 01a and 1otb, φ130mm, thickness 1.2
The revolving substrate holder 106 on which six plastic substrates 105 of
It was arranged so that the distance was 0 mm. On the substrate 105, 840 optical films 5iJ4 are formed in advance. The ultimate pressure of the vacuum chamber 103 is 5.0×10-'Torr,
Ar gas flow ffi35secM, sputtering pressure 2,
It was set to 0 Torr.

Each of the targets is supplied with power by target power supplies 104a and 104b which are DC power supplies, and the power supplied to the Kugera 101a is 900W, and the power supplied to the target 101b is 1900W to maintain discharge. The revolution speed of the substrate holder 106 is set to 30
Rotate at rpm and perform film formation for 200 seconds to deposit Tb and FeC.

1,000 people formed alternately laminated thin films. As a result of taking out this sample and measuring its characteristics, the measurement position from the disk center was R = 30 + n + u, the rotation speed was 180 Orpm,
The average value of the samples under the conditions of a write frequency of 3.71 MHz is C/N (0.9 μ bit length) 48.9 d.
B. Envelope 0. It was 7dB.

As is clear from comparing the results of this comparative example with the above-mentioned examples, the substrate manufactured by the present invention has a higher C/C ratio than the substrate manufactured by the conventional sputtering apparatus.
It was possible to obtain a magneto-optical disk with good dynamic properties such as N and envelope properties.

[Brief explanation of drawings]

FIG. 1 is a schematic side view of an embodiment of a sputtering apparatus for carrying out the method of the present invention, FIG. 2 is a block diagram showing a control system of the sputtering apparatus shown in FIG. 1, and FIG. 3 is an optional A waveform diagram showing examples of waveforms and control timing of the waveform generator, FIG. 4 is a schematic diagram of the film thickness at the transfer position of the sputtering chamber, FIG. 5 is a schematic diagram of a conventional substrate revolution type sputtering apparatus, and FIG. FIG. 7 is a schematic diagram of a conventional substrate rotation type sputtering apparatus. FIG. 7 is a schematic diagram of a conventional substrate passing type sputtering apparatus. (Symbols in the figure) 1...first sputtering target, 2a, 2b
-111 second sputtering target, 3-center cathode, 4a, 4b...both end cathodes, 5.6a
, 6b--permanent magnet, 7.8a, 8b--cooling channel, 9.10 a, 10 b-sputtering power source, 11--one substrate, 12--m-substrate mask, 13...-one substrate holder 4-111 conveyor roll, 15.16--earth shield, 17--exhaust system, 18--gate valve, 19.2
0.21... Sputtering chamber. 23a, 23b-arbitrary waveform generator, 24...control means. Funeral diagram 11

Claims (2)

[Claims] (1) A plurality of rectangular sputtering targets are elongated and faced in a direction orthogonal to the transfer direction of the substrate, which is the object to be film-formed, and at least a first sputtering target is placed on the substrate.
and a second substrate-passing sputtering method for forming a magneto-optical recording layer made of a thin film of a different metal,
A rectangular second sputtering target made of the second metal is arranged in parallel so as to face each other along the substrate traveling direction at a position sandwiching the rectangular first sputtering target made of the first metal, Further, the magneto-optical recording layer is constituted by a laminated thin film by alternately discharging the first sputtering target and discharging the second sputtering target while at least the substrate passes through a film-forming region. A sputtering method characterized by: (2) Alternate discharge of the first sputtering target and the second sputtering target is performed based on the frequency and waveform of a signal generated by an arbitrary waveform generator, and the frequency is set within the film forming region. 2. The sputtering method according to claim 1, wherein the sputtering method is controlled in accordance with a change in film formation rate at the substrate position.