JPH0375363A - Sputtering device - Google Patents

Abstract

PURPOSE:To form a thin film uniform in thickness even if a target is short in the magnetron-type continuous sputtering device by the passage film forming method by providing a regulation member for forming a slit of specified shape above the target. CONSTITUTION:A substrate holder 7 is continuously moved to the right in the figure and transferred to a sputtering chamber 15, substrates A, B and C are successively arranged on the holder 7 in the direction orthogonal to the transfer direction while rotating a table 6, and a thin film is formed on the substrates. In this device, the target 1 is formed by a long rectangular flat plate horizontally extending in the arranging direction of the substrates. The regulation members 12 and 13 for forming a slit extending in the longitudinal direction of the target are provided above the target 1. The width of the slit opening is made larger at the parts close to both ends of the substrate in the arranging direction than at the central part.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a sputtering apparatus, and particularly to a sputtering apparatus that continuously performs sputtering to form a thin film on a continuously transferred substrate.

[Prior art]

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

The magneto-optical disk has a multilayer structure consisting of a dielectric layer, a recording layer, a protective layer, etc. formed on a transparent substrate such as glass or plastic. For example, the recording layer exhibiting the magneto-optical effect may be a mixed film or a laminated film of a rare earth metal (hereinafter referred to as RE) and a transition metal (hereinafter referred to as TM), and a thin film forming such a thin film may be used. A sputtering method is available as a forming method.

The sputtering method involves introducing an inert gas such as Ar gas into a low-pressure atmosphere to generate a glow discharge, and irradiating a cathode target with ions in the plasma to knock out structural atoms and molecules from the surface of the target material. This is a thin film forming method in which a thin film is deposited on the surface of a substrate on an anode substrate holder placed so as to face the target, and is widely used industrially.

Among the above-mentioned ¥1 film-forming methods, the magnetron sputtering method, in which a magnetic field component is formed on the target almost parallel to the target, and the electric field and the magnetic field are almost orthogonal, has a fast film formation rate and has a low temperature of the substrate to be sputtered. It has the effect of suppressing the increase in temperature, and is widely used in the manufacturing process of semiconductors and magnetic recording media as a very effective thin film forming method.

Next, a conventional manufacturing apparatus for a recording layer of a magneto-optical recording medium will be described.

One type of conventional manufacturing equipment is a magnetron-type sputtering equipment called a rotational film deposition method.The basic structure of this is that a rotating holder is installed in the sputtering chamber above the chamber, and the film is deposited on this holder. Further, in the lower part of the sputtering chamber, for example, two magnetron sputtering cathodes each have a circular target made of RE gold metal 7M metal, which is a film forming material, to generate a magnetron discharge. In order to make this possible, permanent magnets are provided on the back side of each target and are arranged at predetermined intervals.

In the rotary film forming apparatus, the holder for holding the substrate, which is provided to face the magnetron sputtering cathode, may have a structure that simply revolves, or a structure that rotates around its axis (having a planetary gear, etc.). There are structural types. In the case of the revolution type, a film thickness distribution correction plate is arranged in order to make the film pressure distribution uniform, and in addition to being movable to open and close, this film thickness distribution correction plate has a plate that corresponds to the orbit of the substrate and a plate that can be opened and closed. In some cases, a substantially fan-shaped slit is formed in the area facing the magnetron sputtering cathode so that the opening width increases toward the outer radius of revolution. There was a drawback that the sex did not improve.

On the other hand, in the case of the rotation-revolution type, the film thickness distribution can be made uniform even without the film thickness distribution correction plate.

According to such a rotational film forming type film forming apparatus, the RE
Since the laminated structure of the metal layer and the TM metal layer can be freely changed, a high-quality magneto-optical recording medium with excellent properties such as the amount of magnetization of the recording layer, coercive force, and magneto-optical effect (Kerr effect) can be obtained. It will be done. Further, since the change in the laminated structure of the recording layer can be controlled by the revolution speed or rotation speed of the substrate holder and the sputtering power ratio applied to both targets, the controllability is relatively good.

However, according to the conventional apparatus, in order to achieve film thickness uniformity, it relies heavily on mechanical operating structures such as the film thickness distribution correction plate and the rotation and revolution mechanism, which is not desirable from the viewpoint of cleanliness in the sputtering chamber. For example, dust caused by sputtered particles adhering to a member of the shutter, which acts as a movable film thickness distribution correcting plate, adheres to the substrate on which the thin screen is formed, producing pinholes in the thin film. Further, in the case of a film thickness distribution correcting plate having fan-shaped slits, the opening area of the slits becomes small and the film formation rate decreases, causing a big problem in productivity.

Moreover, in the above-mentioned rotation-revolution type film forming apparatus, the work of attaching the substrate to the rotation-revolution mechanism is complicated and difficult to automate, resulting in low productivity. In addition, the drive mechanism is complicated and the equipment cost is high, and there are also problems in maintainability.

Furthermore, in the above-mentioned rotary film-forming type film-forming apparatus, each layer such as the dielectric layer, protective layer, recording layer, etc. is formed on the substrate in separate sputtering chambers, so opening the sputtering chamber is unnecessary. Of course, this is necessary for each sputtering process, and chucking is also required when the substrate holder is transferred between the sputtering chambers and when attached to the rotating shaft within each sputtering chamber. For this reason, there is a problem that the setting time of the substrate holder becomes long and productivity is not improved.

Therefore, in order to improve the productivity, a continuous sputtering apparatus using a passing film forming method as shown in FIG. 5 has been adopted.

The continuous sputtering device using the pass-through film forming method has a plurality of vacuum chambers, each having an independent exhaust system, of which sputtering chambers 126, 127, and 128 are continuously provided.
Then, sputtering is performed continuously. The sputtering chamber 12
6, 127, and 128 are communicated and separated by a gate valve 131. Then, the plurality of substrate holders 121 guided by the transport rolls 120 forming a transport path are
The sputtering chamber 126, 127, 128 is configured to be continuously transported at a constant speed. Further, the substrate holder 121 holds a plurality of plastic substrates 125 arranged horizontally in a direction perpendicular to the direction of transfer thereof.

For example, in the sputtering chamber 127, a magnetron sputtering cathode 122 is placed at the bottom of the sputtering chamber 127 as a film forming material.
E Gold Metal TM Gold Metal has a rectangular alloy target 123 extending horizontally in a direction perpendicular to the substrate conveyance direction,
In order to enable magnetron discharge, the target 12 is placed on the back side of the target with a gap 25 in the form of a rectangular annular shape when viewed from above, as shown in FIG. 6, for example.
A permanent magnet 124 corresponding to the entire area of 3 is provided. Furthermore, a shutter 129 is disposed above the alloy target 123 in order to adjust the film formation time of the film formation layer on the plastic substrate 125.

The alloy target 123 is connected to a target power source 130, which applies sputtering power suitable for the alloy target 123 to form a desired alloy thin film. Furthermore, as described above, the alloy target 123 is arranged horizontally and has a rectangular shape extending in a direction perpendicular to the transfer direction of the substrate holder 121, and the length of the alloy target 123 in the longitudinal direction is usually , has conventionally been set to about 1.6 to 2.0 times the total length of the diameters of the plastic substrates 125 (A, B, C) arranged in parallel on the substrate holder 121 for practical purposes. .

Therefore, in the continuous sputtering apparatus of the passing film formation method, sputtering is performed while the plurality of plastic substrates 125 (A, B, C) arranged in parallel on the substrate holder 121 are continuously transferred and films are formed simultaneously. , productivity is greatly improved.

[Problem to be solved by the invention]

However, in the continuous sputtering apparatus using the pass-through film forming method, the film thickness of the thin film formed on the plastic substrate 125B installed at the central part of the substrate holder 121 in the direction perpendicular to the direction of transport and the thickness of the thin film formed on the plastic substrate 125B installed at both ends of the direction of transport plastic substrate 125 (A.

C) There was a difference in the thickness of the thin film formed thereon. This problem is caused by the plastic substrate 125 at both ends.
The problem with so-called mounting, in which the film thickness of (A, C) is smaller than that of the center film, is that the film thickness differs depending on the position. This is because when the elongated target 123 is used, the film formation rate is extremely low at both ends of the sputtering chamber due to the substrate travel line as shown in FIG. A measure was taken to make the longitudinal length of the alloy target 123, which extends horizontally in a direction orthogonal to the transfer direction, sufficiently longer than the width of the substrate running line. However, if the length of the alloy Targera) 123 in the longitudinal direction is increased, naturally,
The magnet 124 is also large, which not only increases the size of the sputtering chamber, but also reduces the adhesion efficiency of the target material to the substrate, resulting in an increase in manufacturing costs.

That is, the purpose of the present invention is to solve the above problems,
The present invention provides a sputtering device that can form a high-quality thin film with good productivity and a uniform film thickness distribution without elongating the target in the direction perpendicular to the transport direction.

[Means to solve the problem]

The above object of the present invention is to provide a sputtering apparatus that continuously performs sputtering using a target disposed opposite to the substrate in order to form a thin film on a substrate that is continuously transferred into a sputtering chamber. A plurality of targets are arranged on a substrate holder in a state perpendicular to the transfer direction, and the target is configured as a long rectangular flat plate extending horizontally along the direction in which the substrates are arranged. A regulating member is disposed above to form a slit extending substantially along the longitudinal direction of the target, and the opening width of the slit is configured such that portions closer to both ends of the substrate in the direction in which the substrate is arranged are larger than the central portion. This is achieved by a sputtering device characterized by:

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

[Embodiment]

FIG. 1 shows a schematic view of the main parts of a sputtering apparatus based on the present invention, and FIG. 2 is a schematic plan view showing the positional relationship between a target and a substrate.

As shown in FIGS. 1 and 2, the sputtering apparatus according to the present invention has a plurality of vacuum chambers each having an independent exhaust system 17, among which sputtering chambers 14 and 15 are provided consecutively. At .16, sputtering is performed continuously. The sputtering chambers 14.15.degree. 16 are separated and communicated by a gate valve 18. The plurality of substrate holders 7 guided by the transport rolls 11 forming a transport path are configured to be continuously transported into the sputtering chamber 14, 15, 16 at a constant speed. Furthermore, a rotatable turntable 6 holding circular plastic substrates A, B, and C, respectively, is provided below the main body of the substrate holder 7. The turntable 6 has a rotating shaft 8 at its center, the rotating shaft 8 passing through the main body of the substrate holder 7 and extending upward, and a pinion 9 near the upper end of the rotating shaft 8. is provided.

The pinion 9 engages a rack 10 fixed to the sputtering chamber 14, 15, 16, and the substrate holder 7
By moving along the conveyance rolls 11, the turntables 6 can be rotated in respective predetermined directions.

For example, in the sputtering chamber 15, a magnetron sputtering cathode 3 has a rectangular alloy target 1 made of RE gold metal 7M metal, which is a film forming material, at the bottom,
A permanent magnet 2 is provided to enable magnetron discharge.

The alloy target 1 is connected to a target power source 4, which applies sputtering power suitable for the alloy target (1) to form a desired thin film. Further, the alloy target 1 is formed in a rectangular shape that is horizontally arranged and extends in a direction perpendicular to the direction in which the substrate holder 7 is transferred.

Further, above the alloy target 1, a regulating member 12.13 is arranged, which constitutes a slit 5 for regulating sputtered particles evaporated from the alloy target layer 1 from adhering to the plastic substrates A, B, and C. It is set up. The regulating members 12.13 are each formed in a plate shape extending along the longitudinal direction of the alloy target 1, and the slit 5 formed by the regulating member 12.13 is wider on the left and right than the slit width W1 in the central portion. Slit width W near both ends! It has a stepped structure that increases the size. Therefore, only when the substrate holder 7 reaches the area above the slit 5, that is, approximately directly above the alloy target 1, the plastic substrates A and B are removed.

The sputtered particles are allowed to adhere to the thick bottom surface of the C thin film. The plastic substrate A.

In B and C, the film forming time differs depending on the substrate movement line, so that the film thickness can be averaged, and a shutter is used to adjust the film forming time to form a thin film on the substrate unlike the conventional one. There is no need to provide one member.

An inert gas such as argon (Ar) gas is introduced from the gas inlet 19 into the sputtering chamber 15 of the sputtering apparatus configured as described above, and sputtering power is appropriately applied to the alloy targeter 1. Then, the plastic substrates A, B, and C on which dielectric layers have been formed in advance are successively mounted on the substrate holder 7.

The substrate holder 7 is continuously transferred to the sputtering chamber 15, and a thin film is formed on the plastic substrates A, B, and C while the turntable 6 rotates within the sputtering chamber.

As described above, according to the present invention, the plurality of plastic substrates A, B, and C are held by the substrate holder 7 and sputtered while being continuously transferred, so that productivity can be improved.

Further, the plastic substrates A, B, and C are transferred while rotating within the sputtering chamber 15, respectively. Furthermore, the plastic substrate A.

The amount of sputtered particles adhering to B and C is determined by the slit 5 formed by the regulating member 12.13 disposed above the alloy target 1, and the amount of sputtered particles adhering to the plastic substrate B and the plastic substrate A, The amount attached to C is set to be almost the same, and at the same time, the particle incident angle is also regulated. That is, the longitudinal direction of the slit 5 (perpendicular direction along the horizontal plane with respect to the substrate transfer line)
The amount of sputtered particles scattered at each position is the same as before, but the film forming time can be set longer for the plastic substrates A and C on the left and right end transfer lines than for the plastic substrate B on the central transfer line. Therefore, the final film thickness will be the same. Furthermore, when sputtered particles adhere to the substrate, sputtered particles with a large incident angle (sputtered particles at both end regions in the transfer direction in the sputtering chamber)
Since it is blocked by the regulating member 12.13,
A magneto-optical disk with uniform film thickness distribution and good dynamic characteristics can be provided.

In the above embodiment, an alloy target made of RE gold and 7M metal was used, but the present invention is not limited to this, and other target materials may be used.

Further, in the embodiment described above, an example was shown in which one plastic substrate is attached to each turntable 6 of the substrate holder 7, and a total of three plastic substrates are mounted and transferred while rotating. The present invention is not limited to this, and it is possible to have more substrates.Also, a sufficient effect can be expected even if a plurality of substrates are attached to a substrate holder and the substrates are transferred while rotating or rotating. It goes without saying that it can be done.

Furthermore, it is clear that the regulating members 12, 13 are not limited to the convex shape but can take various shapes. For example, as shown in FIG. 3, the regulating members 12 and 13 may have a curved profile such that the slit width corresponding to the center portion of the board running line is the minimum and the slit width gradually widens in the left-right direction. Although not described in detail in the embodiment, the permanent magnet 2 has an elongated rectangular S pole (the magnetic pole is indicated by diagonal lines in the figure) in the center, and a rectangular ring shape surrounding the S pole. The magnet is constructed as one continuous magnet with a rectangular ring-shaped N pole substantially matching the outline of the target 1 with a gap between them.

〔Effect of the invention〕

As described above, since the sputtering apparatus of the present invention is configured to continuously perform sputtering to form a thin film on a continuously transferred substrate, the sputtering apparatus of the present invention continuously performs sputtering to form a thin film on a continuously transferred substrate. Sputtering can be performed, improving productivity. In addition to this excellent productivity, the sputtered particles evaporated from the target are evaporated in the direction perpendicular to the substrate transport direction due to the change in the opening width of the slit formed by the regulating member disposed between the substrate and the target. Since the amount of adhesion to the plurality of substrates lined up can be regulated, in order to form a thin film with a uniform thickness on the plurality of substrates held in the substrate holder, it is possible to increase the amount of target material in the longitudinal direction of the target, unlike conventional methods. It is possible to avoid film thickness differences due to the mounting position of the substrate on the substrate holder without having to do so, promoting the miniaturization of the sputtering chamber, eliminating variations in product quality, and achieving extremely high productivity and high quality. be able to.

〔Example〕

Hereinafter, the effects of the present invention can be further clarified with reference to Examples.

A sample magneto-optical disk was prepared using the sputtering apparatus of the present invention shown in FIGS. 1 and 2.

The alloy target 1 is placed in the sputtering chamber 15, with a width of 130a.
m, length: 600mm, thickness: 5mm Tb,,
Fe,. A targeter l-1 made of C07 material is arranged horizontally and is installed so that its longitudinal direction extends perpendicularly to the direction of transport of the substrate. Like the one shown in FIG. 3, the magnet 2 had an S pole at the center and an N pole at the outer periphery.

In addition, plastic substrates A, B, and C with a thickness of 1.2 mm and a diameter of 130 m each have a center distance of 150 ff and 111 mm.
The vertical distance between the alloy target 1 and the plastic substrates A, B, and C is 120 m.
It was set as m.

Furthermore, the width W of the central portion of the slit 5 is set to 250I.
In II11, the width W2 of both end portions was set to 30011III+. Then, the pressure inside the sputtering chamber 15 is increased by 5×
After evacuation to 10-'Torr, 403 CCM of Ar gas was introduced from the gas inlet 19 to bring the gas pressure to 2.0.
mTorr. Next, after applying a discharge power (DC power) of 5 kW to the target to maintain sputter discharge, the substrate holder 7 holds the plastic substrate A,
150 m while rotating B and C at 2 rpm each
A magnetic film was formed on the plastic substrates A, B, and C by transporting at a transport speed of m/win. FIG. 4 shows the film thickness ratio at the substrate position in the left-right direction (horizontal direction and perpendicular to the substrate transport direction) of the sputtering chamber 15 at this time.

Further, Tbz3Fe adhered to each of the substrates after film formation.

The thickness of the C07 film was measured using a step meter. The results are shown in Table 1.

(Margin below) Table 1 As is clear from Table 1, the variation in film thickness is ±2.0%.
Very good results were obtained.

Next, as a comparison with the above-mentioned Example 1, a conventional sputtering apparatus as shown in FIG. 5 was used.

The alloy target 123 is placed in the sputtering chamber 127 with a width of 1
A piece of Tbzx Fe7°Co measuring 27mm, length: 610aa, thickness: 5IIIfl, is arranged horizontally in a rectangular configuration with its longitudinal direction perpendicular to the transport direction of the substrate. Built to extend. In addition, plastic substrates A, B, and C with a thickness of 1.2 mm+ and a diameter of 130 mm have a center distance of 150 m, respectively.
The alloy target 1 is mounted on the substrate holder 121 with
The vertical distance between 23 and the plastic substrates AB and C is 1
00m.

Then, the pressure inside the sputtering chamber 15 was set to 5X10-'T.
After evacuation to orr, 403 CCM of Ar gas was introduced from the gas inlet 19 and the gas pressure was set to 2.0 mTorr.
It was set as r. Next, 8.0k was applied to the alloy target 123.
After applying a discharge power (DC power) of W to maintain sputter discharge, the substrate holder 7 rotates each of the plastic substrates A, B, and C at 2 rpm while
The plastic substrates A and B were transferred at a conveyance speed of 0 mm/win.

A magnetic film was formed on C. The sputtering chamber 1 at this time
FIG. 6 shows the film thickness ratio at the substrate position of No. 27 in the left-right direction (horizontal direction perpendicular to the substrate transport direction). In addition, after the film formation, TbzsFe7°C attached to each of the substrates
o? The thickness of the film was measured using a step meter. Table 2 shows the results.
Shown below.

Table 2 As can be seen from Tables 1 and 2 as well as Figures 4 and 7, in the conventional case, the variation in film thickness was about ±40%, and in the embodiment of the present invention, the variation was ±2. ．． Much better results were obtained, with the difference being within 0%.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of the main parts of a sputtering apparatus based on the present invention, FIG. 2 is a schematic plan view showing the positional relationship between the target and the substrate, and FIG. 3 is a plan view showing another shape of the regulating member. FIG. 4 is a distribution diagram showing the relationship between the substrate position in the left-right direction of the sputtering chamber (horizontal direction and perpendicular to the substrate transport direction) and the film thickness ratio in the embodiment of the present invention, and FIG. FIG. 6 is a distribution diagram showing the relationship between the substrate position in the left-right direction of the sputtering chamber (horizontal direction perpendicular to the substrate transport direction) and the film thickness ratio in a conventional film-type continuous sputtering apparatus. (Symbols in the diagram) 1... Alloy target, 2,124... Permanent magnet, 3... Magnetron sputtering cathode, 4... Target power supply, 5... Slit, 6... Turntable, 7... Substrate holder 8... Rotating shaft, 9...
Binion, 10... Rack, 11... Conveyance roll, 12.13... Stationary member, 14.15.
16... Sputtering chamber, 17... Exhaust system, 18.131... Gate valve, 19... Gas inlet, 120... Transport roll, 121... Substrate holder,
122... Magnetron sputter cathode, 123.
... Alloy target, 125 ... Plastic substrate (A, B, C), 126
．． 127.128... Sputtering room, Figure 4 Conductive film it, i if T1 (part side) Procedural amendment flat bottom 1st year October sunset

Claims (1)

[Claims] In order to form a thin film on a substrate that is continuously transferred into a sputtering chamber, a sputtering apparatus that performs continuous sputtering using a target placed opposite to the substrate, in which the substrate is moved in a direction perpendicular to the transfer direction. A plurality of targets are arranged side by side on a substrate holder, and the target is configured as a long rectangular flat plate extending horizontally along the direction in which the substrates are arranged, and above the target is a plate extending in the longitudinal direction of the target. A sputtering apparatus characterized in that a regulating member is disposed to form a slit extending substantially along the substrate, and the opening width of the slit is larger at a portion near both ends in a direction in which the substrates are arranged side by side than at a central portion.