JPH0826453B2 - Sputtering equipment - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a sputtering apparatus used for manufacturing a magneto-optical recording medium used for a large-capacity data file or the like, and more specifically, it uses a sputtering method at the same time. The present invention relates to a sputtering device that forms an alloy thin film layer.

[Conventional technology]

In recent years, magneto-optical recording media have been used as large-capacity data files as magneto-optical disks that can be written and read by laser light. This magneto-optical disk has a layer structure such as a dielectric layer, a recording layer, and a protective layer on a transparent substrate such as glass or plastic by a sputtering method. The recording layer exhibiting a magneto-optical effect is composed of a mixed or laminated thin film of a rare earth metal (hereinafter referred to as "RE metal") and a transition metal (hereinafter referred to as "TM metal").

Next, the sputtering method for forming a thin film will be briefly described. Sputtering technology in low pressure atmosphere
A glow discharge is generated by an inert gas such as Ar gas,
This is a technique in which ions in plasma are made to collide with a cathode target to knock out atoms from a target material to deposit a thin film on a substrate arranged so as to face the target, which is widely used industrially. In particular, the magnetron sputtering method, which is characterized by forming a magnetic field component approximately parallel to the target and making the electric field and the magnetic field orthogonal to each other, has a high film formation rate and is effective in suppressing the temperature rise of the substrate to be sputtered. As a very useful method, it is widely used in the manufacturing process of magnetic recording media and semiconductors.

A conventional sputtering apparatus for forming a magnetic recording layer of a magneto-optical recording medium is disclosed in, for example, JP-A-63-11664.
No. 63-171878, No. 63-22779, etc. are disclosed variously, but the basic structure thereof is shown in FIGS.
It will be described with reference to the drawings. FIG. 10 shows a sputtering apparatus called a rotary film forming apparatus. The magnetron sputtering cathode 100 provided on the lower side of the vacuum chamber 103 in the figure has, for example, a permanent magnet 102 on the back side, and
Circular targets 101a and 101b made of RE metal and TM metal are connected to the sputtering power sources 104a and 104b and are arranged at a predetermined interval. A substrate 105 is fixed to a revolving substrate holder 106 at a position facing the targets 101a, 101b, and the revolving substrate holder 106 revolves around a rotation shaft 108 corresponding to substantially the center of the targets 101a, 101b, An RE metal and a TM metal are alternately deposited on the substrate to form a mixed thin film. In this device, since the structural change of the recording layer can be controlled by the rotation speed of the revolution substrate holder 106 and the power ratio applied to the respective targets 101a and 101b, the comparative controllability is good, and the magnetization amount of the recording layer and the retention In order to obtain excellent characteristics of magnetic force and magneto-optical effect (Kerr effect), the laminated structure of the RE metal layer and the TM metal layer can be freely changed, so that a high quality medium can be formed.

In order to obtain high-quality magneto-optical disks from the results of previous research, it is necessary to ensure that the film thickness distribution is within ± 5%.
It is preferably within ± 3%. However, in general, in a film forming apparatus that simply revolves without the film thickness distribution correcting plate 107 or the like, the film thickness distribution of the recording layer on the circular substrate, that is, When the dynamic characteristics of a magneto-optical disk are evaluated, the C / N and the envelope characteristics in the disk circumferential direction, that is, the carrier signal fluctuations in the disk circumferential direction are large, which is not good. Is likely to occur. Therefore, conventionally, as shown in FIG. 10, in addition to the substrate revolution structure, a film thickness distribution correction plate 107 is installed to correct the film thickness. On the other hand, as another method, in addition to the substrate revolution holder 106 as in the device shown in FIG. 11, a structure having a rotation shaft 114, a fixed gear 112, a planetary gear 113, etc. can revolve the substrate 105. It is like this.

However, the former method shown in FIG. 10 has a problem that pinholes are formed on the film formation surface due to the influence of dust generated by the film deposited on the film thickness distribution correction plate 107 or the like. The latter method shown in FIG. 11 does not require the film thickness distribution correction plate 107, but has a drawback that the rotation mechanism is complicated. Furthermore, as it can be said for the entire rotary film forming method, since the film formation of each of the dielectric layer, the protective layer, and the recording layer is performed in each independent film forming chamber, transfer between the substrate holder chambers,
A process such as chucking for attaching the rotating shaft of the substrate holder to the rotating means is required. There is a fatal problem that the substrate transportation that does not directly participate in film formation and the proportion of setting time for film formation preparation are large and productivity does not increase,
It was the most important issue in terms of cost.

In order to solve the above problems of the pallet rotating type sputtering apparatus, a substrate passage type sputtering apparatus as shown in FIG. 12 has been proposed for the purpose of improving productivity. In this apparatus, an alloy target 123 composed of an intermetallic compound of RE metal and TM metal (hereinafter referred to as IMC) (or an alloy target composed of three elements of RE metal, TM metal and IMC) is connected to a sputtering power supply 130, Permanent magnet 124 on the back
The rectangular sputtering cathode 122 having the above is provided, and the substrate 125 is made of the target material while facing the target surface and being transported at a constant speed in the direction (arrow A direction) perpendicular to the longitudinal direction of the target 123. This is a device for forming a recording layer. In this apparatus, usually, the substrate 125 is placed on the substrate
The productivity is greatly improved because the films are formed in parallel and continuously moved. The drawback of this substrate-passing type sputtering apparatus is mainly due to the characteristics of the alloy target 123. That is, when an alloy thin film is formed using the alloy target 123, the emission angle distribution of the target element (sputtered particles) toward the substrate by the alloy target 123 differs depending on each element. This is, for example, for a sample attached to a plurality of substrates placed in a stationary state facing the alloy target 123, when examining the composition ratio of the constituent elements of the thin film for each sample, the center of the target 123 Regarding the sample at the position facing the part, the ratio of RE metal is high, and the target 123
As for the sample at the position facing the outer portion of, the proportion of RE metal 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, and thus at the time of starting the film formation. (At the position on the left side of the sputtering chamber in the figure), the deposition rate of RE metal is small, and thereafter, at the position facing the central portion of the alloy target 123, the proportion of RE metal is large, and then on the right side of the sputtering chamber. Then, along with the line through which the substrate 125 passes, such that the proportion of RE metal decreases,
Until the film forming step is completed, a slight change in the composition will accompany. When the ratio of the composition change is large, there is a characteristic problem of C / N deterioration. Another major drawback of the alloy target 123 is that the composition ratio gradually changes as the target is used for a long time. Accordingly, there is a problem that the life of the alloy target 123 is shortened, and replacement is required, thereby increasing the cost of the product.

As described above, the applicant previously applied as a film forming method for solving the problem of the emission angle distribution of the sputtering particles of the alloy target, which is a drawback of the substrate-passing type sputtering apparatus, and the problem of composition deviation during long-term use. Japanese Patent Application No. 62-248876 (see Japanese Patent Laid-Open No. 1-91342) is proposed. It targets RE metal and TM as target
By using separate single metals, the RE metal targets are located on both sides of one TM metal target, and the RE metal targets are tilted to face each other in order to make the film thickness distribution uniform. is there.

The inventor of the present invention has conducted intensive studies based on the method of Japanese Patent Application No. 62-248876 to provide a higher quality magneto-optical recording medium. It has become clear that the positional relationship between the substrate and each of the targets, the dimensional relationship in the moving direction, the tilt angle of the target to be tilted, and the like, have a favorable effect on the film thickness distribution and the composition distribution with a certain law relationship. ing.

[Object of the Invention] An object of the present invention is to improve the quality of a magnetic recording medium, since at least the formed recording layer has a uniform film thickness distribution and a uniform composition ratio and can be formed at a high film forming rate. It is an object of the present invention to provide a sputtering apparatus that can realize the above-mentioned, and can realize a low manufacturing cost.

[Structure of Invention]

It is an object of the present invention to provide a substrate-passing type in which a plurality of sputtering targets are opposed to a substrate that is a film formation target, and an alloy thin film layer made of alloy thin films of at least first and second metals is formed on the substrate. In the sputtering apparatus, a second rectangular metal sputtering target formed of the second metal is sandwiched between the second rectangular metal sputtering target and the second rectangular metal sputtering target.
Of the rectangular sputtering targets are arranged in parallel along the traveling direction of the substrate, and the two second rectangular sputtering targets are inclined so as to face each other. The angle formed between the sputtering plane and the sputtering plane of the second rectangular sputtering target is α, and the length of the short side of the first rectangular sputtering target along the substrate traveling direction is a, and When the length of the short side of the rectangular sputtering target of No. 2 along the substrate running direction is b and the distance between the sputtering plane of the first rectangular sputtering target and the substrate is Lts, the following formula (1) 0.6 ≤a / b≤2.0 (2) 40 ° ≤ α ≤ 90 ° (3) 1.0 ≤ Lts / a ≤ 2.0 This is achieved by a sputtering apparatus that is configured to satisfy the relationship. Door can be.

Hereinafter, embodiments of the present invention illustrated in the drawings will be described in detail.

[Embodiment]

FIG. 1 is a schematic view of a sputtering apparatus according to one embodiment 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 that they can communicate with each other, and in the continuous sputtering chambers 19, 20, 21 a desired thin film is formed. You can do it. Then, the transport roll 14 that constitutes the transport path.
Guided by the plurality of substrate holders 13 into the sputtering chamber 1
It moves at a constant speed in 9,20,21. A substrate 11, which is, for example, a circular film-forming target, is fixed to the bottom of the substrate holder 13 by a substrate mask 12. The number of substrates 11 held by the substrate holder 13 may be plural. The holding position of the substrate 11 can be easily changed by moving the bottom surface of the substrate holder 13 or by changing the other substrate holders themselves.

On the bottom side of the sputtering chamber 20, a central cathode 3 and cathodes 4a and 4b on both sides of the central cathode 3 are installed. For example, the first rectangular sputtering target 1 made of RE metal The second rectangular sputtering targets 2a and 2b made of TM metal are juxtaposed in the sandwiching position along the substrate traveling direction (direction of arrow A). On the back side of the first rectangular sputtering target 1 and the two second rectangular sputtering targets 2a, 2b, a permanent magnet for generating a leakage magnetic field on the surface of each target.
5,6a, 6b are installed, and the earth shields 15,16 are also installed in proper places so that abnormal discharge does not occur between both targets.

Further, the cathodes 4a and 4b at both ends are positioned so as to be inclined to face each other, and the sputtering plane of the first rectangular sputtering target 1 and the second rectangular sputtering targets 2a and 2b, respectively. The angle α formed with the sputter plane is fixed at any angle within the range of at least 40 ° to 90 °. The holding structure for the cathodes 4a and 4b at both ends is a well-known structure such as bolt tightening, and is omitted in FIG.

The length a of the short side of the first rectangular sputtering target 1 along the substrate running direction and the length b of the short side of the second rectangular sputtering target 2a, 2b along the substrate running direction. The relationship is constructed such that at least 0.6 ≦ a / b ≦ 2.0.

Furthermore, the relationship between the distance Lts between the surface of the first rectangular sputtering target 1 and the substrate 11 and the length a of the short side of the first rectangular sputtering target 1 along the substrate traveling direction is: It is configured so that it can be set within the range of at least 1.0 ≦ Lts / a ≦ 2.0.

Inside the permanent magnets 5, 6a, 6b, cooling water channels 7, 8a, 8b for adjusting the target temperature are formed, and the rectangular sputtering targets 1, 2a, 2b are sputtered respectively. Power supplies 9, 10a, 10b are connected.

Furthermore, the setting method of the sputtering apparatus of this embodiment will be described in detail.

First, by using the sputtering apparatus shown in FIG. 1, a current is made to flow only to the first rectangular sputtering target 1 by the sputtering power source 9 to perform sputtering of RE metal to sample the plurality of substrates 11 which are sample disks ( 1) was created. A plurality of sample disks (2) were prepared by applying a current to the second rectangular sputtering targets 2a and 2b by the sputtering power supplies 10a and 10b to sputter TM metal.

The conditions at this time are that the second rectangular sputtering targets 2a and 2b are installed with an inclination angle α = 20 °, and the first rectangular sputtering target 1 is a short side along the substrate traveling direction. Has a length of 89 mm, a long side in the lateral direction with respect to the substrate traveling direction has a length of 305 mm, and a thickness of 5 mm.
In the rectangular sputtering targets 2a and 2b, the short side length along the substrate running direction is 76 mm, the long side length transverse to the substrate running direction is 305 mm, the thickness is 4 mm, and the sputtering power source 9 is used. Input power 600W, sputter power 10
The input power by a and 10b was set to 1KW. The diameter of each sample disk is φ130 mm, the thickness is 1.2 mm, and the glass is used as a material. The glass is mounted on the substrate holder 13 and faces the cathode, and is separated from the surface of the first rectangular sputtering target 1.
A thin film is formed on a parallel surface separated by Lts while moving at a constant speed of 4 mm per second.

FIG. 2 shows the target disk-substrate distance (Lts) of the sample disk (1) and the sample disk (2) of the substrate 11 changed. It is the graph which investigated the change of.

As can be seen from FIG. 2, both the sample disk (1) and the sample disk (2) have a target-substrate distance (Lt
It can be seen that as s) increases, the film thickness distribution worsens.
Judging from the results of the research so far, it is necessary to keep the allowable range of film thickness distribution of RE metal and TM metal within ± 5.0%, judging from the characteristics of magneto-optical disks. Therefore, under each of the above conditions, it can be set as one criterion that the film thickness distribution is within ± 5.0%. Considering this criterion, the first rectangular sputtering target 1 and the substrate 11 are considered.
The distance (Lts) between and is inevitably set to be 80 mm or less under the above conditions.

Next, based on the results shown in FIG. 2, the distance (Lts) between the first rectangular sputtering target 1 and the substrate 11 is set to 80 mm, and all the substrates to which the substrate 11 moves are set. Fig. 3 shows the results of examining the film thickness from each substrate sample that was formed by placing two or more glass substrates uniformly on the moving line and performing independent sputtering of RE metal only or TM metal only twice. Indicated. The dimensions of the first rectangular sputtering target 1 and the second rectangular sputtering targets 2a and 2b are the same as those in the case of FIG.
W, the input power from the sputtering power sources 10a and 10b was 1.6 KW.

(1) in FIG. 3 shows the case where the film thickness ratio of a specific film thickness of RE metal is 1.0, and it can be seen that the deposition rate at the center is high. On the other hand, in (2), the thickness ratio of the TM metal is also shown in the same manner as that of the RE metal, and it can be seen that the deposition rate at both ends of the sputtering chamber 20 is high and the center is low. From this result, in the actual film formation process, if the film is formed while the disk moves from the left end to the right end in FIG. It can be seen that the film formation process is completed by passing through a region having a high proportion of TM metal and a low proportion of TM metal, and then again passing through a region having a high proportion of TM metal. Therefore, in the film forming process, the sputtering chamber 20
The RE metal in the center and both ends are roughly divided into three areas.
A change in the composition ratio of TM metal occurred, and from this experiment, when the inclination angle α was about 20 degrees, the film thickness distribution showed a large variation as the total film thickness distribution of the RE metal and TM metal alone. Even if it does not exist, the composition deviation is ± 1
It turns out that it will be a large value of 9.0%.

Judging from the characteristics of the magneto-optical disk based on the research results so far, it is known that the composition deviation in the film needs to be within ± 5.0%, and preferably within ± 3.5%.
From the above reason, it is understood that the film forming conditions that satisfy the film thickness distribution characteristics do not necessarily set the conditions that satisfy the composition distribution.

Based on the above reason, among the conditions of the film thickness distribution and composition, the first characteristic that must be suppressed as the characteristic of the magneto-optical recording layer is the RE of the thin film formed on the substrate 11.
It is the homogeneity of the composition of the metal and the TM metal. As described above, if the composition deviation is large, the C / N and the sensitivity characteristics of the magneto-optical disk are significantly deteriorated, which is a very serious problem. Therefore, it is necessary to set the value within the above range.

The details of the sputtering apparatus of this embodiment are set.

First, the RE metal which is the first rectangular sputtering target 1 and the second rectangular sputtering target 1
Consider the effective geometry of 2a, 2b TM metals. The length (a) of the short side of the first rectangular sputtering target (center target) 1 along the substrate traveling direction and the substrate traveling direction of the second rectangular sputtering target (targets at both ends) 2a, 2b Prepare a target (the magnetron magnet on the back surface of the target changes its size accordingly) in which the ratio (a / b) of the lengths of the short sides (b) along the is changed from 0.4 to 2.0 (first The length (a) of the short side of the rectangular sputtering target is fixed), the inclination angle of the second rectangular sputtering targets 2a and 2b is changed in the range of 0 to 90 °, and the first rectangular target is changed. Between the sputtering target 1 and the substrate 11 (Lt
s) and the length (a) of the short side of the target 1 (Lts
/ a) is changed in the range of 0.4 to 2.2, and the minimum value (±%) that can be taken for the composition deviation of the film when a mixed thin film of RE metal and TM metal is formed by the apparatus shown in FIG. )
I checked. The RE metal that is the first rectangular sputtering target has a short side length (a) along the substrate running direction.
Is 89 mm, and the length of the long side in the lateral direction with respect to the board running direction is 30
The second rectangular sputtering target, TM metal, is 5 mm in thickness and 5 mm in thickness. The short side length (a) is variable and the thickness is
The length is 4 mm, the substrate is a plastic resin with a diameter of 130 mm and a thickness of 1.2 mm, and the length of the long side of each target in the lateral direction with respect to the substrate running direction is 305 mm as described above, so that the length does not affect the composition deviation. It is a long one. The input power is 500 W for RE metal and 800 W for TM metal, and the moving speed of the substrate holder is 3 mm / sec.

FIG. 4 shows the results. Since the allowable range of the composition deviation is within ± 5.0%, only the composition ratio is at least in the area within the dotted line (diagonal line) along the vertical axis in the figure. Must be in. From the above results,
The relationship between the length (a) of the short side of the first rectangular sputtering target 1 along the substrate traveling direction and the length (b) of the short side of the second rectangular sputtering targets 2a and 2b is as follows. It can be seen that it is necessary to satisfy at least the condition of 0.6 ≦ a / b ≦ 2.0 when the length ratio is (a / b).

Next, the second rectangular sputtering target 2a, 2
In order to set the inclination angle (α) of b, consideration will be given to the inclination angle α, composition deviation and film thickness distribution.

FIG. 5 is a graph of experimental results showing the relationship between the composition deviation (%) of the mixed thin film formed on the substrate 11 and the inclination angle α. The distance (Lts) between the first rectangular sputtering target 1 and the substrate 11 is fixed at 10 mm, and the other conditions are that the length of the short side of the first rectangular sputtering target 1 along the substrate traveling direction is 89 mm, the long side in the lateral direction with respect to the substrate traveling direction is 305 mm, and the thickness is 5 mm.
In the rectangular sputtering targets 2a and 2b, the short side length along the substrate running direction is 76 mm, the long side length transverse to the substrate running direction is 305 mm, the thickness is 4 mm, and the sputtering power source 9 is used. Input power is 350W, the sputter power supply 10
The input power by a and 10b was set to 1.4KW. The diameter of each sample disk was φ130 mm, and the thickness was 1.2 mm. The material was made of plastic resin and moved at a constant speed of 4 mm per second. From this result, the composition deviation ± 5.0% when the inclination angle is 40 ° or more.
The following effective ranges can be found:

On the other hand, FIG. 6 shows the relationship between the inclination angle (a) and the film thickness distribution. Good results can be obtained by setting at least the limit of the film composition deviation. That is, it is possible to find an effective range of the film thickness distribution ± 5.0% or less when the inclination angle α of the second rectangular sputtering targets 2a and 2b is set to 40 ° or more.

From the above, it becomes clear that the minimum value of the inclination angle of the second rectangular sputtering targets 2a and 2b needs to be inclined by at least 40 degrees or more.

Now, when the inclination angle is gradually increased by 40 degrees or more, the film composition deviation and the film thickness distribution are improved.
If the angle exceeds 90 degrees, another problem will occur. That is, since sputtered particles are usually ejected from the surface of the target in a relationship close to the cosine law, when the tilt angle α exceeds 90 degrees, the second rectangular sputtering targets 2a and 2b.
Not only does not face the direction of the substrate 11, but
This is not preferable because the projection of sputtered particles from the rectangular sputtering target 1 is blocked and the film forming rate is sharply reduced. From the above reason, it is understood that the inclination angle (α) of the second rectangular sputtering targets 2a and 2b is preferably in the range of 40 ° ≦ α ≦ 90 ° for the above reason.

Next, the length (a) of the long side of the short side along the substrate traveling direction of the first rectangular sputtering target and the first
The setting in relation to the distance (Lts) between the rectangular sputtering target 1 and the substrate 11 will be considered.

FIG. 7 shows the distance (Lts) between the first rectangular sputtering target (center target) 1 and the substrate 11,
The experimental results are shown in a graph in which the ratio (Lts / a) to the length (a) of the short side of the target 1 is on the horizontal axis and the composition deviation is on the vertical axis. The inclination angle (α) of the second rectangular sputtering targets (targets on both ends) 2a, 2b is constant at 40 degrees, and the other conditions are that the first rectangular sputtering target 1 is along the substrate traveling direction. The length of the short side
89mm, 305m in the long side in the horizontal direction with respect to the board running direction
m, thickness 5 mm, the second rectangular sputtering target 2a, 2b has a short side length of 76 mm along the substrate running direction, a lateral length of 303 mm with respect to the substrate running direction, a thickness of 4 mm,
The power supplied by the sputtering power source 9 was 350 W, and the power supplied by the sputtering power sources 10a and 10b was 1.4 KW. The diameter of each sample disk was φ130 mm, and the thickness was 1.2 mm. The material was made of plastic resin and moved at a constant speed of 4 mm per second. The first rectangular sputtering target 1
And the distance (Lts) between the substrate 11 and the substrate 11 and the length (a) of the short side of the first rectangular sputtering target 1 (Lts /
The composition deviation in the sample disk of the mixed thin film of RE metal and TM metal when a) was changed in the range of 0.8 to 1.8 is the allowable value of composition deviation ± (rts / a) in the range of 1.0 or more.
It is within 5.0%, which is good.

On the other hand, FIG. 8 shows that, under the same conditions as in FIG. 7, the inclination angle (α) of the second rectangular sputtering targets (targets on both ends) 2a, 2b is constant at 40 degrees.
The distance (Lts) between the first rectangular sputtering target (center target) 1 and the substrate 11;
Length of short side of rectangular sputtering target 1 (a)
R when the ratio (Lts / a) to and is changed in the range of 0.6 to 1.8
The changes in the film forming rates of E metal and TM metal are shown.

As can be seen from FIG. 8, the film formation rate decreases as the value of (Lts / a) increases, and it is not desirable that the film formation rate be too low in terms of production speed. I can say. Therefore, the deposition rate is the highest
In the region of 50% or less, the feature of high productivity fried as a merit of the above-mentioned passage type sputtering apparatus disappears. Therefore, the upper limit of (Lts / a) is considered to be about 2.0. From the above results, the relationship between the target-substrate distance (Lts) and the short side length (a) of the first rectangular sputtering target 1 is 1.0 when the length ratio is (Lts / a).
It can be seen that the range of ≦ Lts / a ≦ 2.0 is most effective.

Using the sputtering device configured as described above
To summarize the process of forming a mixed thin film of RE metal and TM metal, first, the substrate holder 13 is conveyed at a predetermined speed into the sputtering chamber 20 which is kept in a desired state for sputtering. Then, the substrate holder 13
In the initial state (the position on the left side in the drawing) in the sputtering chamber 20, the second rectangular sputtering target 2b is appropriately adjusted so as to face left and is inclined.
The mixed film of both metals starts to adhere to the substrate 11 due to the TM metal sputtered particles scattered from and the RE metal sputtered particles scattered from the first rectangular sputtering target 1. After that, with the movement of the substrate holder 13, the sputtered particles of TM metal protruding from the second rectangular sputtering target 2b gradually decrease,
The TM from the second rectangular sputtering target 2a on the left side in the figure placed on the opposite side so as to replace this
During the sputtering process (the range where the substrate passes through the sputtering chamber), the sputtered particles of metal gradually increase.
TM The metal scattering level can be kept average and stable as a whole. On the other hand, although the RE metal sputtered particles scattered from the first rectangular sputtering target 1 are the most above the center position of the target, the scattering characteristics of the RE metal sputtered particles are The directivity is lower than that of the above scattering characteristics and is relatively averaged, and there is no practical problem due to the control of the sputtering power sources 9, 10a and 10b.

Therefore, since the alloy thin film formed on the substrate 11 has the same thickness and composition ratio as that of the sputtering apparatus of the present invention described above, the high-quality magneto-optical recording is achieved over the entire substrate. A medium can be provided.

The present invention is not limited to the above-described embodiment, for example, the transport structure of the substrate holder 13 can be variously changed, and the permanent magnets 5, 6a, 6b can be freely changed to control the magnetic field strength by changing to electromagnets. can do.

Further, the first rectangular sputtering target 1
May be TM metal, and the second rectangular sputtering targets 2a, 2b may be made of RE metal.

〔The invention's effect〕

As described above, the sputtering device of the present invention is
A second rectangular sputtering target made of the second metal is arranged in parallel along the substrate traveling direction at a position sandwiching the first rectangular sputtering target made of the first metal,
And the two second rectangular sputtering targets are inclined and positioned so as to face each other, and the sputtering plane of the first rectangular sputtering target and the sputtering plane of the second rectangular sputtering target are The angle (α) between them and the length (a) of the short side of the first rectangular sputtering target along the substrate traveling direction.
A length (b) of a short side of the second rectangular sputtering target along the substrate traveling direction, and a distance (Lts) between the sputtering plane of the first rectangular sputtering target and the substrate. It is configured so that it can be controlled so as to keep the relational expression with a certain range.

Therefore, it becomes possible to always maintain the average and stable scattering levels of a plurality of sputtered metals as a whole during the sputtering process (the range in which the substrate passes through the sputtering chamber), and to obtain a uniform film thickness distribution and a uniform composition ratio. In addition, since the target is made of a single material, it has a long target life and can form a recording layer of an excellent magneto-optical recording medium at a high film-forming rate for a long time. It is possible to provide a sputtering apparatus capable of manufacturing a magneto-optical recording medium that realizes a bottom price.

〔Example〕

Hereinafter, the effects of the present invention can be further clarified by examples.

Example 1. In the sputtering apparatus shown in FIG. 1, Tb as a RE metal target was used as the first rectangular sputtering target 1.
(Short side length 89 mm x long side length 305 mm x thickness 5 mm) is mounted, and Fe ₂₀ Co ₈₀ (short side length 76 mm x length is used as a TM metal target on the second rectangular sputtering targets 2a and 2b. I installed a side length of 305 mm x thickness of 4 mm). The inclination angle (α) of the second rectangular sputtering targets 2a and 2b was set to 40 °. Electric power is supplied to each of the targets by a target power supply 9, 10a, 10b which is a DC power supply, and the electric power supplied to the second rectangular sputtering targets 2a, 2b is adjusted to be the same as described below. did. The target-substrate distance (Lts) is set to 110 mm, and sputtering is performed twice with the substrate 11 made of a glass material being uniformly placed on the substrate movement line at all positions where the substrate 11 moves. It was

In the first sputtering, 300 W of power was supplied to the first rectangular sputtering target 1 from the DC power source 9 for sputtering, and the film formation was performed for 90 seconds. The film thickness of the thin film attached to the substrate 11 and the position of the substrate 11 at that time were as shown in (1) of FIG.

In the second sputtering, 1450 W of power was supplied to the second rectangular sputtering targets 2a and 2b from the sputtering DC power supplies 10a and 10b, respectively, and the film formation was performed for 90 seconds. The film thickness of the thin film attached to the substrate 11 and the position of the substrate 11 at that time were as shown in (2) of FIG.

When both sputtering targets 1, 2a, 2b are simultaneously sputtered, the composition ratio deviation is ± 4.0%,
We were able to secure the composition deviation within ± 5.0%. Further, in the apparatus shown in FIG. 1, a glass substrate 11 having a diameter of 130 mm and a thickness of 1.2 mm is attached to the substrate holder 13 while keeping the same geometrical conditions, and the substrate holder 13 is moved to the first position.
After preparing at the left end of the figure, set the sputter power source 9 to 300 W and the sputter power sources 10a and 10b to 1450 W,
While moving the substrate holder 13 on which the substrate 11 is mounted from the film formation start position at the left end of FIG. 1 toward the right side of the drawing at a moving speed of 6 mm / sec, the Tb target 1 and the Fe ₂₀ Co ₈₀
A mixed thin film composed of sputtered particles of both materials of the targets 2a and 2b was formed on the substrate 11. After completion of this film formation, the film thickness distribution of the substrate 11 was examined and found to be ± 4.8%, and it was possible to secure the allowable range of film thickness distribution within ± 5.0%.

Example 2 In the sputtering apparatus of FIG. 1, Tb (length of short side 89 mm × length of long side 305 mm × thickness 5 mm) was used as the RE metal target of the first rectangular sputtering target 1 attached to the central cathode 3. Attach the cathodes 4a and 4
The second rectangular sputtering target 2a attached to b,
2b as TM metal target Fe ₂₀ Co ₈₀ (short side length 76mm
X long side length 305 mm x thickness 4 mm) was attached. Inclination angle (α) of the second rectangular sputtering targets 2a, 2b
Was set at 45 °. The targets 1, 2a, 2b were adjusted by the sputtering power sources 9, 10a, 10b so that the electric power supplied to the targets 2a, 2b at both ends was the same. Optical film on φ130mm × 1.2mm thick plastic
The substrate 11 on which 850 Å of Si ₃ N ₄ is formed is mounted on the substrate holder 13 via the substrate mask 12, and the substrate holder 13
Was prepared at the film formation start position at the left end of FIG.

The distance (Lts) between the moving line of the substrate 13 and the first rectangular sputtering target 1 was set to 110 mm.
The vacuum chamber (sputter chamber 20) containing the entire cathode was evacuated by the exhaust system 17 to 5.0 × 10 ⁻⁷ Torr, and then Ar gas was introduced into the vacuum chamber to set 2.0 × 10 ⁻³ Torr. did. A power of 500 W is applied to the first rectangular sputtering target 1 by a sputtering power source 9, and a sputtering power source 10a is applied to the second rectangular sputtering targets 2a and 2b.
And 10b, power of 1600 W was applied to each and pre-sputtering was performed for 5 minutes. After that, set the sputtering power source 9 to 400
W, set the sputter power supply 10a and 10b to 1400W,
While moving the substrate holder 13 on which the substrate 11 is mounted from the film formation start position at the left end in FIG. 1 to the right side in the drawing at a moving speed of 4 mm / sec, the first rectangular sputtering target 1 and the first rectangular sputtering target 1 2 rectangular sputtering target 2
A mixed thin film composed of sputtered particles of both materials a and 2b was formed on the substrate 11. TbFeC having a total film thickness of 900Å and a composition ratio of FeCo: Tb = 1: 0.8 by the film forming process.
o A magneto-optical recording layer was formed. Take this sample,
The result of measuring the dynamic characteristics. Measuring position R from the center of the disc
= 30mm, speed 1800rpm, frequency 3.71MHz
The C / N (0.9 μbit length) was 48.1 dB, the envelope was 1.2 dB, and the sensitivity was 6.6 mW. As a result of measuring the dynamic characteristics of a sample of a magneto-optical disk prepared by the same method as above after performing continuous discharge of 15 KW by performing continuous discharge in the above sputtering device, C / N 48.0 dB, envelope 1.0 dB, sensitivity 6.7. It showed the same good characteristics regardless of continuous use of mW and target.

Comparative Example As a practical example of the conventional method, a film forming method and an apparatus for passing film will be described. In FIG. 12, TbFeCo was placed in the sputtering chamber 127.
Of the rectangular alloy target 123 (Tb ₂₂ Fe ₇₀ Co ₈ , short-sided) prepared by mixing the intermetallic compound (about 30 at,%) with Tb, Fe, Co Length 127 mm x long side length 3
05mm x 5mm) magnetron cathode 122 for ferromagnetic material
Built in. The substrate holder 121, which faces the target surface and moves on a plane parallel to the target surface in a direction perpendicular to the longitudinal direction of the target (direction of arrow A), has a substrate of φ130 mm and a thickness of 1.2 mm, which is a plastic disk substrate. 125
Install one. The vertical distance (Lts) between the target and the plane on which the substrate holder moves was set to 80 mm.
The substrate holder 125 was equipped with one substrate on which an optical film of Si ₃ N ₄ was previously formed in a thickness of 800 Å, and was left stationary at the position B in the sputtering chamber 127. Evacuate with a vacuum pump to evacuate the pressure to 5 × 10 ^-7 Torr, then Ar gas 42sccm
Was introduced into the vacuum chamber and the gas pressure was 2.2 mTorr.
Next, with the shutter 129 closed, the alloy target 1
23: DC; maintain spatter at a discharge power of 1.0 KW. When the sputter discharge is stabilized, the substrate holder 121 including the substrate 125 starts moving at a transfer speed of 160 mm / min. Immediately after the moving speed becomes constant, the shutter 129 is opened immediately and moving film formation is performed for 150 seconds. The shutter 129 was closed and a magnetic layer with an average film thickness of 900Å was formed. The result of taking out this sample and measuring its dynamic characteristics was as follows.

As a result, in the measurement position R = 30 mm from the center of the disk, the rotation speed 1800 rpm, the writing frequency 3.71 MHz, under the conditions,
The C / N (0.9 μbit length) was 46.7 dB, the envelope was 3.0 dB, and the sensitivity was 7.8 mW.

As a result of measuring the dynamic characteristics of a sample of a magneto-optical disk produced by the same method as above after performing continuous discharge at 15 KW in the sputtering device, C / N 44.3 dB, envelope 3.3 dB, writing sensitivity 7.
It became 6mW.

Comparing the results of this comparative example with the above-mentioned respective examples,
It is apparent that the embodiment according to the present invention can provide a magneto-optical disk having excellent characteristics.

[Brief description of drawings]

FIG. 1 is a schematic side view of an embodiment of a sputtering apparatus of the present invention, FIG. 2 is a graph showing a relationship between a target-substrate distance (Lts) and a film thickness distribution, and FIG. 3 is a substrate in a sputtering chamber. FIG. 4 is a graph showing the change in film thickness at the substrate position along the traveling direction. FIG. 4 shows the ratio (a / a) of the short side length (a) of the central target and the short side length (b) of both end targets. b), tilt angle α and target −
FIG. 5 is a graph showing the relationship between the composite condition of the distance between substrates (Lts) and the film forming composition deviation, FIG. 5 is a graph showing the relationship between the inclination angle α and the film forming composition deviation, and FIG. 6 is the inclination angle α and the film. Fig. 7 is a graph showing the relationship with the thickness distribution, and Fig. 7 shows the ratio (Lts / a) between the target-substrate distance (Lts) and the short side length (a) of the central target when the inclination angle α is constant. ) And the film composition deviation, FIG. 8 shows the distance between target substrates (Lts) when the inclination angle α is kept constant at 40 degrees.
To the short side length (a) of the center target (Lts /
FIG. 9 is a graph showing the relationship between a) and the film formation rate, and FIG. 9 is a graph showing the change in film thickness at the substrate position along the substrate traveling direction in the sputtering chamber when the inclination angle α is kept constant at 40 degrees. FIG. 10 is a schematic diagram of a conventional substrate revolution type sputtering device, FIG. 11 is a schematic diagram of a conventional substrate revolution revolution type sputtering device, and FIG. 12 is a schematic diagram of a conventional substrate passing type sputtering device. (Numerals in the drawing) 1 ... First rectangular sputtering target, 2a, 2b ... Second rectangular sputtering target, 3 ... Central part cathode, 4a, 4b ... Both end cathodes, 5, 6a, 6b ... Permanent magnet, 7,8
a, 8b ... Cooling channel, 9, 10a, 10b ... Sputtering power source, 11 ... Substrate, 12 ... Substrate mask, 13 ... Substrate holder, 14 ... Conveying roll, 15, 16 ... Earth shield, 17 ... Exhaust system, 18 ... Gate valves, 19, 20, 21 ... Sputter chamber.

Claims (1)

[Claims] 1. A substrate-passing type sputtering apparatus in which a plurality of sputtering targets are opposed to a substrate which is a film formation target, and an alloy thin film layer made of alloy thin films of at least first and second metals is formed on the substrate. The second rectangular sputtering target made of the second metal is arranged in parallel along the substrate traveling direction at a position sandwiching the first rectangular sputtering target made of the first metal, and the two first The two rectangular sputtering targets are positioned so as to face each other, and the angle formed between the sputtering plane of the first rectangular sputtering target and the sputtering plane of the second rectangular sputtering target is α. And the length of the short side of the first rectangular sputtering target along the substrate running direction is a, and the second rectangular sputtering target is When the length of the short side of the tuttering target along the substrate running direction is b and the distance between the sputtering plane of the first rectangular sputtering target and the substrate is Lts, the following formula (1) 0.6 ≦ a / b ≦ 2.0 (2) 40 ° ≦ α ≦ 90 ° (3) 1.0 ≦ Lts / a ≦ 2.0 The sputtering apparatus characterized in that the structure is satisfied.