JPH0379760A - Sputtering device - Google Patents

Abstract

PURPOSE:To form films having a uniform film thickness distribution by constituting the target disposed opposite to continuously moving substrates in such a manner that the central part thereof is a rectangular horizontal target surface and both ends are rectangular inclined target surfaces. CONSTITUTION:A substrate holder 7 is continuously passed via transporting rolls 11 in continuously provided sputtering chambers 14, 15, 16. The films are formed onto the circular plastic substrates A, B, C held on a turn table 6 provided at a holder 7 by the target provided in the lower part. The target is made into the rectangular shape having the horizontal target surface 1b parallel with the substrates A, B, C and the inclined target surfaces 1a, 1b (the angle alpha of inclination is about 0 to 80 deg.) on both sides of the horizontal target surface 1b. This target is intersected orthogonally with the transfer direction of the substrates. Permanent magnets 2a, 2b, 2c forming the magnetic fields orthogonal with electric fields are provided on the rear surface of the target. The target is sputtered in this constitution and the films are formed on the substrates A, B, C, by which the film thicknesses in the effective film forming region are uniformized.

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.

This magneto-optical disk has a multilayer structure including 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 product NM of a rare earth metal (hereinafter referred to as RE) and a transition metal (hereinafter referred to as TM), and it is difficult to form such a thin film. There is a sputtering method as a thin film 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 the cathode target with ions in the plasma to knock out structural atoms and molecules from the surface of the target material. This is a fl film formation method in which a thin film is deposited on the surface of a substrate on an anode substrate holder placed to face the target, and is widely used industrially.

Among the above-mentioned thin 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 made almost orthogonal, has a fast film forming speed and suppresses the temperature rise of the substrate to be sputtered. This method is widely used in manufacturing processes of semiconductors and magnetic recording media as a highly effective method for forming FI films.

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 TM gold metal, which is a film forming material, and 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 provided to face the magnetron sputtering cathode may have a structure that simply revolves, or a structure that rotates around itself (having a planetary gear, etc.). There is. In the case of the revolution type, a film thickness distribution correction plate is arranged to make the film thickness distribution uniform, and in the case of the 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. Instead, for example, dust caused by sputtered particles adhering to the film thickness distribution correction plate adheres to the substrate on which the thin film is formed, generating pinholes in the thin film.

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. 6 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 the sputtering chambers 126°, 127°, and 128° are continuously provided.
Then, Suba Nyu is held continuously. The sputtering chamber 1
26, 127, and 128 are communicated and separated by a gate valve 131. A plurality of substrate holders 121 are guided by a transport roll 120 that forms a transport path.
is configured to be continuously transferred into the sputtering chambers 126, 127, and 128 at a constant speed. Also,
The substrate holder 121 holds a plurality of plastic substrates 125 arranged in a direction J and perpendicular to the direction of transport 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 23 located in a plane horizontal to the substrate transport direction and with the long side direction of the target perpendicular to the substrate transport direction, and has a magnetron. In order to enable discharge, a permanent magnet 124 is installed on the back side of the target so as to cover the entire area of the alloy target eye 23 so that a gap 25 is left between the two poles, each of which has a rectangular annular shape when viewed from above, as shown in FIG. 7, for example. We are prepared. In addition, a shutter 129 is disposed above the alloy target 123 in order to adjust the film forming time of the film layer formed on the plastic substrate 125.

123 is the target power source 130
The alloy target 123 is connected with a suitable spanner power so that a desired laminated thin film can be formed. Further, as described above, the alloy target eye 23 is a rectangle located in a plane horizontal to the transfer direction of the substrate holder 121, and the long side direction of the target is perpendicular to the transfer direction of the substrate. Generally, the length of the alloy target 123 in the longitudinal direction is approximately 1.0 mm from the total length of the diameters of the plastic substrates 125 arranged in parallel to the substrate holder 121 from a practical point of view. It is set to about 6 to 2.0 times.

Therefore, in the continuous sputtering apparatus using the passing film forming method, the plurality of plastic substrates 125 arranged in parallel on the substrate holder 121 are continuously transferred and sputtered to form films at the same time, which greatly improves productivity. do.

[Problem to be solved by the invention]

However, in the continuous sputtering apparatus using the pass-through film forming method, the average film thickness of the thin film formed on the plastic substrate 125 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 125 installed at both ends of the direction of transport There is a difference in the average film thickness of the thin film formed on the plastic substrate 125 at both ends.
There is a problem in so-called mounting that the average film thickness of 25 is thinner than that of the center one, and that there is a difference in film thickness depending on the position. As is clear from the thickness distribution of the thin film in the direction perpendicular to the transport of
This is because the film thickness at both ends in the longitudinal direction of the rectangular target becomes low.For example, the film thickness of the rectangular target 1
Compared to this, the film thickness of 3M4 formed on the substrates A, B, and C arranged in parallel in the direction perpendicular to the transfer of the substrate holder on the substrate holder 23 is the same as that of the center substrate A. It becomes thinner than it is thick. Note that the normalized film thickness in Figure 8 is the ratio of the film thickness at each measurement position when the maximum film thickness is l, and each measurement position is indicated by the distance when the center of the sputtering chamber is the origin of the coordinates. Ta.

Therefore, in the past, the longitudinal direction of the alloy target 123 is horizontal to the direction of transfer of the substrate holder 121, and the long side direction of the target is located perpendicular to the direction of transfer of the substrate holder 121. A measure was taken to make the length in the direction sufficiently longer than the width of the board running line.

However, increasing the length of the alloy target 123 in the longitudinal direction 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 apparatus capable of forming a high-quality 'a film with good productivity and uniform film thickness distribution without elongating the target in the direction perpendicular to the transport direction.

[Means for Solving the Problems] The above object of the present invention is to form a thin film on a substrate that is continuously transferred into a sputtering chamber by continuously sputtering with a target disposed opposite to the substrate. In the sputtering apparatus, the target has a rectangular horizontal target surface parallel to the substrate, and a long side direction of the entire target is in the substrate transport direction with the horizontal target surface in between. and rectangular inclined target surfaces arranged in parallel to face each other at right angles to the surface of the target. This is achieved by a sputtering apparatus with vP@, in which a magnetic field generating means for forming a magnetic field along the target is provided in a shape corresponding to the entire back surface of the target.

Hereinafter, one embodiment B of the present invention will be described in detail.

[Implementation Mr. B]

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, 1516 are separated and communicated by gate valves 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. Also,
A rotatable turntable 6 holding circular plastic substrates A, B, and C, respectively, is provided on the lower side of the main body of the substrate holder 7. The turntable 6 is
It has a rotating shaft 8 at its center, which extends upward through the main body of the substrate holder 7, and a pinion 9 is provided near the upper end of the rotating shaft 8. The pinion 9 engages with a rack 10 fixed to the sputtering chamber 14, 15, 16, and as the substrate holder 7 moves along the transport roll 11, the turntable 6 is moved in a predetermined direction. It can be rotated.

For example, at the bottom of the sputtering chamber 15, a central magnetron sputtering cathode 3b and magnetron sputtering cathodes 3a and 3c on both sides of the central magnetron sputtering cathode 3b are installed, and each of them contains RE, which is a film forming material. A tilted target l is placed at a position sandwiching a rectangular horizontal target 1b made of gold metal 7M metal.
The horizontal targets Ia and lc are arranged in parallel along the horizontal orthogonal direction to the substrate transfer direction (see Figure 3). Permanent magnets 2a, 2b, and 2c are installed near the target surface to generate a leakage magnetic field along the surface so as to be substantially perpendicular to the electric field.

In addition, the horizontal target 1b and the inclined target
1a and le are each connected to an independent sputtering chamber a4.

Furthermore, the both end magnetron sputter cathode 3a,
3c are installed at an angle so as to face each other, and the angle α between the sputtering plane of the horizontal target (1a) lb and the sputter plane of each of the (horizontal targets 1a+lc) is at least 10 degrees. It is configured so that it can be fixed and held at any angle within the range of ~80 degrees.

Therefore, 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 the sputtering power is adjusted appropriately to the horizontal target lb and the inclined targets la and lc. is attached, and the substrate holder 7 is
the plastic substrate A on which a dielectric layer is previously formed;
Attach B and C one after another.

The substrate holder 7 is continuously transferred to the sputtering chamber 15, and the plastic substrate A is transferred to the sputtering chamber 15.

B and C are each rotated and transferred within the sputtering chamber by the turntable 6, and a thin film is formed on the surface of each substrate.

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.

In addition, the particles scattered from the surfaces of the inclined target plates (La, lc) which are installed in an inclined manner so as to face each other are the plastic bases FiA, B.

C scatters toward both ends of the effective film-forming area in the direction perpendicular to the direction of transport. Therefore, sputtered particles are also supplemented at both ends of the effective film forming region in the direction perpendicular to the transport direction, where the film thickness is low, so that the film thickness within the effective film forming region can be made uniform. Therefore, the plastic substrates A and B
, C, or an increase in the number of substrates B, the plastic substrates A and C, which pass through both end portions in the direction perpendicular to the transfer direction of the sputtering chamber, are also free of the plastic substrates B and B. Since the same amount of sputtered particles can be deposited, it is possible to eliminate variations in film thickness depending on the position when attaching multiple plastic substrates, and the film thickness distribution between each substrate can be made uniform. The uniformity of the film thickness distribution is also improved, and a magneto-optical disk with good dynamic characteristics can be provided.

In the embodiment described above, the horizontal target (lb) and the inclined target (la), (lc) each have an independent magnetron magnetic circuit and are composed of three electrically insulated magnetron sputtering cathode blocks, but the apparatus of the present invention is not limited to this, and may be composed of one magnetron sputter cathode block. In this case, the permanent magnet 20 disposed on the target layer l-21- surface side is formed such that both poles are spaced apart from each other by a rectangular annular gap 21 when viewed from above, as shown in FIG. A horizontal portion 22 and inclined portions 23 and 24 that are inclined in directions facing each other are formed at both ends.

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

Further, in the embodiment B, 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 attached and transferred while rotating. The number of substrates is not limited to 1, but it is also possible to have a larger number of substrates.Also, it is sufficient to carry out film formation by mounting a plurality of substrates on a substrate holder and transporting the substrates while stationary, revolving, or rotating. Needless to say, the effects can be expected.

[Effects of the Invention] As described above, the sputtering apparatus of the present invention forms a thin film on a substrate that is continuously transferred into a sputtering chamber, so that a target disposed opposite to the substrate is attached to the substrate. It consists of a rectangular horizontal target plane parallel to the target plane, and rectangular inclined target planes arranged in parallel to face each other in a direction orthogonal to the substrate transfer direction with the horizontal target plane in between, and the target plane A magnetic field generating means is disposed on the back surface side of the target and forms a magnetic field along the target surface so as to be substantially orthogonal to the electric field near the target surface, and is provided in a shape corresponding to the entire back surface of the target to continuously perform sputtering. is configured to do so.

Therefore, sputtering can be performed continuously even during the time required to set the substrate holder, which not only improves productivity. Since the sputtered particles are scattered toward both ends of the effective film forming area of the substrate in the direction perpendicular to the transport direction, sputtered particles are also supplemented at both ends of the effective film forming area in the transport direction where the film thickness is low, and the effective film forming area The inner film thickness can be made uniform.

Therefore, in order to form a thin film with a uniform thickness on multiple substrates held in a substrate holder, the thickness of the film depends on the mounting position of the substrate on the substrate holder, without having to enlarge the target in the longitudinal direction as in the conventional method. The difference can be avoided, the size of the sputtering chamber can be reduced, and the quality of the product can be made uniform. In addition, the target material can be saved and extremely high production efficiency can be obtained.

[Example〕 Hereinafter, the effects of the present invention will be further clarified through Examples.

EXAMPLE 1 A sample magneto-optical disk was prepared using the sputtering apparatus of the present invention shown in FIGS. 1 to 3.

The magnetron sputter cathode block arranged in the sputtering chamber consists of a central magnetron sputter cathode 3b with a horizontal target 1b of TbxJI3voC (1+ material) of size TbxJI3voC (width: 130 mm, length: 400 mm, thickness: 5a). , Width: 130 mm, Length: 150 ms,
Thickness: Tb, Fe, with the size of 5 pieces. Co? from both ends magnetron sputtering cathodes 3a, 3c with inclined targets 1a, 1c of material, the horizontal target 1b and the inclined target plane) la,
The angle α between each sputter hand of lc is 3
It was set to 0 degrees.

Further, plastic substrates A, B, and C having a thickness of 1.2 m and a diameter of 130 mm are each mounted on the substrate holder 7 with a center distance of 150 m, and the horizontal target tb and the plastic substrates A, B, and C are connected to each other with a center distance of 150 m. The vertical distance was 100 meters.

Then, the pressure inside the sputtering chamber 15 is set to 5XIO-'T.
After evacuation to orr, 40SCCM of Ar gas was introduced from the gas inlet 19 to raise the gas pressure to 2.0 mTo.
rr, then 4.0k to the central target 1b.
A discharge power (DC power) of W is applied, and a discharge power (DC power) of 2.0 kW is applied to the targets 1a and Ic at both ends.
After applying a force of 1 g to maintain sputtering discharge, the substrate holder 7 transports the plastic substrates A, B, and C at a conveying speed of 150 m/sin while rotating each of the plastic substrates A, B, and C at 2 rpm. A magnetic film was formed on B and C. The normalized film thickness at the substrate position in the left-right direction (direction perpendicular to the substrate transport direction) of the sputtering chamber 15 at this time is shown in FIG. 4, and the Tbz3Fel adhered to each substrate after film formation. Go? The thickness of the film was measured at multiple locations using a step meter. Table 1 shows the average film thickness.

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 FIGS. 6 and 7 was used.

Alloy target 123 arranged in sputtering chamber 127
fPM: 127 m, length: 610 m, thickness:
One rectangle Tb2) Fe? . The target is made of Co7 material and is assembled so that its longitudinal direction is in a plane parallel to the direction of transfer of the substrate, and the long side direction of the target is located perpendicular to the direction of transfer of the substrate. . In addition, the plastic substrates A, B, and C of the plates with a thickness of 1.2 u and a diameter of 130 have a center distance of 150 mm, respectively.
123 and the plastic substrate A.

The vertical distance between B and C was 100 square meters.

Then, the pressure inside the sputtering chamber 15 was set to 5X10-'T.
After evacuation to orr, 405 CCM of Ar gas was introduced from the gas inlet 19 and the gas pressure was increased to 2.0 CCM. Q mTo
7.0 to the alloy target 123
After maintaining sputtering discharge by applying a discharge power (DC1i force) of kW, the substrate holder 7 rotates each of the plastic substrates A, B, and C at 2 rpm and transports them at a conveying speed of 150 as/l1in. A magnetic film was formed on the plastic substrates A, B, and C.

The normalized film thickness at the substrate position in the left-right direction (horizontal and perpendicular direction to the substrate transport direction) of the sputtering chamber 127 at this time is shown in FIG. 8, and the TbtsPet attached to each of the substrates after film formation. The thickness of the Cot film was measured at multiple locations using a step meter. Table 2 shows the average film thickness.

Table 2 As can be seen from Table 2, the variation in film thickness formed by conventional sputtering equipment is approximately ±4.0%.
It can be seen that the film thickness distribution is clearly inferior to that of the examples of the present invention.

Further, the distribution of the normalized film thickness at the substrate position in a plane horizontal to the substrate transport direction in FIGS. 4 and 8 and where the long side direction of the target is orthogonal to the transport direction. As is clear from the comparison, in the sputtering apparatus of this example, the distribution of the film thickness ratio is improved to be uniform.

[Brief explanation of drawings]

1 is a schematic view 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 a target and a substrate, FIG. 3 is a sectional view showing the configuration of a magnetron sputtering cathode, and FIG. Figure 4 is a distribution diagram showing the relationship between the substrate position and the normalized film thickness in the left-right direction of the sputtering chamber (in a plane horizontal and perpendicular to the substrate transport direction) in an example of the present invention. A plan view showing the magnetic pole shape of a magnetron sputtering cathode based on another embodiment of the present invention, FIG. 6 is a schematic view of the main part of a conventional continuous sputtering apparatus using a passing film forming method, and FIG. 7 is a plan view of a conventional magnetron sputtering cathode. A plan view showing the magnetic pole shape, and FIG. 8 is a distribution showing the relationship between the substrate position in the left-right direction of the sputtering chamber (in a plane horizontal to the substrate transport direction and perpendicular direction) and the normalized film thickness in a conventional apparatus. It is a diagram. (Symbols in the figure) la, lc...tilt target, 1b...horizontal target 2a+2b+2C'/'permanent magnet, 3a, 3c...both end magnetron sputter cathode, 3b...center magnetron sputter cathode, 4・
... Sputtering power supply, 6... Turntable, 7... Substrate holder 8... Rotating shaft, 9... Binion, 10... Rack, 11... Conveyance roll, 14, 15.16. ... Sputtering room, 17...
・Exhaust system, 18... Gate valve, 19... Gas inlet, 20... Permanent magnet, 21.25.
...Gap 22...Horizontal part, 23.24...Slanted part, 120...Transport roll, 121...Substrate holder, 122...Magnetron sputtering cathode, 123...
... Alloy target, 124 ... Permanent magnet, 12
5...Plastic substrate, 126.127.128...Sputtering chamber, 29...Shutter 30...Sputtering power supply, 31...Gate valve. Figure 2 Figure Figure 1M firing size) also AI pu L (To/ff+) Figure Figure Figure Figure S Membrane size 1 Ii-x (ml size)

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, the target being parallel to the substrate. A rectangular horizontal target surface is arranged in parallel with the horizontal target surface at an angle so that the long side direction of the entire target faces the substrate transport direction at a position where the long side direction thereof is orthogonal to the substrate transport direction. a rectangular inclined target surface, and magnetic field generating means is disposed on the back side of the target and forms a magnetic field along the surface so as to be substantially orthogonal to the electric field near the target surface, covering the entire back surface of the target. A sputtering device characterized by being provided in a corresponding shape.