JPH0456766A - Vacuum conveyor - Google Patents

Abstract

PURPOSE:To uniformize the thickness of a film on a substrate by providing a conveying rack and a pinion for turning a substrate holding turntable to a substrate holder and a pinion to be meshed with the rack and pinion and a rack provided with a movable part at its end to a vacuum chamber. CONSTITUTION:A substrate holder 30 has a conveying rack 15, the racks 15 are arranged at regular intervals in vacuum chambers 21a-21c, meshed with a conveying pinion 14 to be driven by a motor and moved, and the holder 30 is accurately conveyed. The holder 30 is also provided with a pinion 28 for turning the turntable 6 for transmitting a torque to each turnable 6 holding a substrate, and a rotating rack 19 to be continuously meshed with the pinion 28 at least in the film forming region is provided on the side walls of the vacuum chambers 21a-21c to turn the pinion 28 and turntable 6. A movable part 37 capable of being elastically moved to the non-meshing side with the pinion 28 is furnished at least on the front end of the rack 19, hence the pressing force when the pinion 28 begins to be meshed with the rack 19 is buffered, and the meshing is smoothly carried out.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a vacuum transfer device, and in particular, when continuously sputtering a substrate to form a thin film on a continuously transferred substrate, the present invention effectively transfers the substrate. The present invention relates to a vacuum conveying device that conveys the image while rotating it.

[Prior art]

Magnetic disks, optical disks, and magneto-optical recording media are widely used for large-capacity data files as magneto-optical disks that can be written and read using laser light, and the manufacturing process for these disks involves forming a thin film on the disk surface. There is a process. In particular, the magneto-optical disk includes a dielectric layer formed on a transparent substrate such as glass or plastic;
It is composed of a multilayer structure consisting of a recording layer, a protective layer, etc., and for example, the recording layer exhibiting a 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). A sputtering method is used as a thin film forming method to form such a thin film.

The sputtering method involves introducing an inert gas such as Ar gas in a low-pressure atmosphere (in a vacuum chamber) to generate a glow discharge, and causing ions in the plasma to collide with a cathode target to remove structural atoms 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 arranged to face the target by knocking out molecules. The magnetron sputtering method, which forms a magnetic field component roughly parallel to the magnetic field and makes the electric field and magnetic field almost perpendicular, has the effect of fast film formation and suppresses the temperature rise of the substrate to be sputtered, making it an extremely effective method for forming thin films. As a method, it is widely used in the manufacturing process of semiconductors and magnetic recording media.

Next, as a basic method of sputtering, for example, an apparatus for manufacturing 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 equipment is a rotating holder installed above the sputtering chamber (vacuum chamber). This holder is configured to mount a film-forming substrate, and furthermore, in the lower part of the sputtering chamber, two magnetron sputtering cathodes each have a circular target made of RE gold metal TM gold metal, which is a film-forming material. However, in order to enable magnetron discharge, 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 pressure 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, in order to achieve film thickness uniformity, such a device relies heavily on mechanical operating structures such as the film thickness distribution correction plate and the rotation and revolution mechanism, so it is not desirable from the viewpoint of cleanliness in the sputtering chamber. For example, dust caused by sputtered particles adhering to the film thickness distribution correction plate is likely to adhere to the substrate on which the thin film is formed and cause 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, but the substrate holder also requires work such as chucking when transferring it between the sputtering chambers and attaching it to the rotating shaft within each sputtering chamber. . For this reason, there was a very serious problem in that the setting time of the substrate holder was increased and productivity was not improved.

Therefore, in order to improve the productivity, a continuous sputtering apparatus using a passing film forming method as shown in FIGS. 5 and 6 has been adopted.

The continuous sputtering apparatus using the pass-through film forming method has a plurality of sputtering chambers, each having an independent exhaust system, and for example, sputtering chambers 140 and 15 that are continuously provided among the sputtering chambers 140 and 15
At 0.160, sputtering is performed continuously. The sputtering chambers 140, 150, and 160 are divided by gate valves 180 so that they can communicate with each other. The transport roll 110 has a drive shaft introduced from the outside of the sputtering chamber into the inside of the sputtering chamber via a feedthrough, and is rotated by a drive device outside the sputtering chamber. The plurality of substrate holders 70 guided by the transport roll 110 forming a transport path are configured to be continuously transported into the sputtering chambers 140, 150, and 160 at a constant speed. Further, the turntable 60 of the substrate holder 70 includes a plurality of circular plastic substrates 125 each having a diameter of about 130 mm, for example, and arranged horizontally in a direction perpendicular to the transfer direction.
is held. Each of the turntables 60 has a rotating shaft 80, and gears meshing with each other are attached to the shafts, and a pinion 90 provided on the rotating shaft 80 near one of the side walls is connected to the rotating shaft 80. By engaging with a rack 100 fixed to the side wall of the sputtering chamber, the substrate holder 70 is configured to rotate as appropriate as the substrate holder 70 moves.

The moving speed of the substrate holder 70 is, for example, 4w.
m/sec, and the substrate rotation speed (turntable rotation speed) is set to about 1 rotation/100o+m. For example, in the sputtering chamber 150, a magnetron sputtering cathode 103 has a rectangular target 101 extending horizontally and perpendicularly to the direction of transport of a substrate made of a film forming material such as Si3N4. However, a permanent magnet 102 is placed on the back side of the target to enable magnetron discharge.

Furthermore, above the target 101, there is a regulating member 12 that constitutes a slit for regulating the incident angle of the sputtered particles evaporated from the target 101 to the substrate.
0.130 is provided. The regulating member 120.1
Reference numerals 30 each indicate a plate member extending in the longitudinal direction of the target, and the slit width W is approximately 200 mm, and this width is formed as a film forming area.

In such an apparatus, it is a well-known fact that the higher the rotation speed of the substrate, the more uniform the film thickness distribution and the formation of a high-performance thin film. The time it takes for the substrates A, B, and C to pass through the film-forming region is about 50 seconds, and the number of rotations of each substrate during this time is about 2 rotations.

[Problem to be solved by the invention]

However, in the continuous sputtering apparatus using the above-mentioned pass-through film forming method, it is difficult to increase the rotational speed of the substrate in order to improve uniformity of film thickness for the following reasons. That is, since the rotation mechanism of the turntable is based on a rack gear and pinion gear, if the pinion diameter is made smaller and the gear ratio is increased to increase the rotation speed of the board holder, the retaining load between the pinion and the rack gear increases. In addition, each time the pinion gear enters each sputtering chamber, it re-engages with the rack placed in that sputtering chamber, so depending on the position of the teeth during this meshing, the meshing may not be successful. , the peaks of the pinion gear and the rack gear may hit each other and cause a gear lock,
Furthermore, if the meshing does not go well, not only will movement of the substrate holder be hindered, but in severe cases, each of the gears may be damaged.

In addition, in the conventional continuous sputtering apparatus using the above-mentioned pass-through film forming method, that is, in a structure in which the substrate holder 70 is transferred by a transport roll 110, the number of turntables is increased to increase productivity, and the number of rotations is increased to improve quality. It has been extremely difficult to increase the amount because it significantly increases the conveyance resistance.

Therefore, an object of the present invention is to solve the above-mentioned problems. For example, when used in a sputtering device, it is possible to increase the number of rotations of a turntable in order to make the film thickness distribution uniform, and it is possible to increase the number of rotations of a turntable in order to make the film thickness distribution uniform. To provide a vacuum transfer device that can ensure reliable rotation even if a table is provided and can increase productivity.

[Means to solve the problem]

An object of the present invention is to provide a plurality of vacuum chambers adjacent to each other with gate valves in between, and to form a thin film on the surface of a substrate attached to a substrate holder that is continuously transferred to each of the vacuum chambers. In the vacuum transfer device that rotates the substrate holder, the substrate holder includes a transfer rack gear, and the substrate holder is moved by engaging with a transfer pinion gear arranged at regular intervals in the vacuum chamber to hold the substrate. A table rotation pinion gear for transmitting rotational force to a rotatable turntable is provided in each vacuum chamber, and the pinion gear continuously engages with the table rotation pinion gear for a certain period at least in the film forming region. Achieved by a vacuum conveying device characterized in that a rotating rack gear for rotating the table is provided, and at least a front end of the rotating rack gear is elastically movable to a side opposite to engagement with the table rotating pinion gear. be done.

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

[Embodiment] FIG. 1 is a schematic side view of the main parts of a sputtering apparatus equipped with the apparatus of the present invention, FIG. 2 is a schematic plan view showing a drive structure for conveying a substrate holder, and FIG. The figure is a partially cutaway enlarged view of the main part of Fig. 2, and Fig. 4 is a schematic diagram of another embodiment, with a part of the main part cut away.

As shown in FIGS. 1 and 2, the sputtering apparatus of this embodiment has a plurality of sputtering chambers (vacuum chambers) each having an independent exhaust system 22, of which sputtering Sputtering is performed continuously in the chambers 21a, 21b, and 21c.

The sputtering chambers 21a, 21b, and 21c are separated by a gate valve 20 (gate valve) so as to be able to communicate with each other as appropriate. In the substrate holder 30, three table shafts 8 are supported by a horizontal support plate 7 extending horizontally from a pallet 9 equipped with a rack gear 15 facing one side wall of the sputtering chamber toward the other side wall. A turntable 6 is rotatably attached to each. Further, each of the turntables 6 is configured to interlock with each other via a gear 27 fixed to each of the table shafts 8 and an intermediate gear (not shown). Then, each sputtering chamber 2
1a, 21b, and 21C are provided with conveyance pinion gears 14 that form conveyance paths at regular intervals, and each drive shaft 16 inserted from the bottom of the sputtering chamber is connected to a motor 10 via a timing belt 12, for example. Driven by. By engaging the rack gear 15 with the transport pinion gear 14, the substrate holder 30 is sequentially transferred at a constant speed (transferred in the direction of the arrow) within the sputtering chambers 21a, 21b, and 21c. 30 is movably supported at a predetermined position by a guide means (not shown).

Furthermore, circular plastic substrates A, B, and C are attached to the lower side of the turntable 6, respectively. Each of the turntables 6 is rotated at an appropriate rotational speed by a substrate rotation pinion gear 28 located on the opposite side of the pallet 9 engaging with a substrate rotation rack gear 19.

The substrate rotation rack gear 19 is connected to each of the sputtering chambers 20a, 20b by a bracket 31 and fixing means such as screws.
, 20c, respectively. The front end and the rear end of the substrate rotation rack gear 19 with which the substrate rotation pinion gear 28 starts to engage can be rotated as appropriate in a substantially perpendicular direction to the tangential direction of the pinion gear 28 using a support shaft 39 as a fulcrum. The movable part 37 is configured.

The movable portion 37 is configured such that the movable portion 37 and the bracket 31 are repulsed by a compression spring 36 disposed between the spring receiving portion 38 of the movable portion 37 and the spring receiving portion 35 of the bracket 31. It is energized as follows. As a structure for stopping the rotation of the rotating part 37 due to this repulsive force, for example, a locking piece 41 is extended to the fixed side on the side surface of the movable part 37, and the locking piece 41 is extended to the fixed side in order to restrict the movement of the locking piece 41. A configuration in which a stopper 40 such as a protrusion is formed can be adopted. Further, in the bracket 31, an inclined surface 33 that allows the movable part 37 to rotate is formed in a portion facing the movable part 37.

For example, in the sputtering chamber 21b, the cathode main body 3 is made of 5is, which is a film forming material for magneto-optical disks, at the bottom.
It has a rectangular target 1 made of Nn, regulating members 5 are provided on both sides of the target, and a magnet 2 is arranged on the back side of the target 1 to enable magnetron discharge. . In addition, each drive shaft 1
6, hermeticity is maintained by members such as a feedthrough 13.

An inert gas such as argon (Ar) gas is introduced into the sputtering chamber 21b of the sputtering apparatus configured as described above, and sputtering power is appropriately applied to the target 1 by the sputtering power source 4. , the plastic substrates A, B, and C are mounted on the substrate holder 30.

The substrate holder 30 is continuously connected to the sputtering chamber 21b.
will be transferred to. Then, in the sputtering chamber, the substrate rotation pinion gear 28 meshes with the substrate rotation rack gear 19 and begins to rotate immediately before the film forming area (the area facing the dowel slit).

At the start of this engagement, the turntable 6 is of course in a stationary state, and due to this inertia, a relatively large contact force (load) is generated when the board rotation pinion gear 28 and the board rotation rack gear 19 are held together. However, at this time, the movable part 37 temporarily retreats (arrow E) about the support shaft 39 so that the board rotation pinion gear 28
Since the abutment force can be buffered in the direction of the rotation direction, the engagement between the board rotation pinion gear 28 and the board rotation rack gear 19 is performed smoothly, and troubles such as gear lock or damage to the gears due to poor meshing between the two gears can be avoided. can be effectively avoided. Further, the board rotation pinion gear 28
Naturally, the positional relationship between the board rotation rack gear 19 and the board rotation rack gear 19 is set so that the gears press each other appropriately so that the gears mesh well with each other. An unexpected load is also likely to occur when the locking mechanism is released, but the rear movable portion 37 can cope with this load as well.

With this configuration that can buffer the impact when the pinion gear 28 for rotating the substrate and the rack gear 19 for rotating the substrate are engaged, poor meshing between the gears can be avoided and the plastic substrates A, B, and C can be Since the gear ratio can be increased to increase the rotation speed, even if there is variation in the amount of sputtered particles scattered upward (the amount of evaporation), the sputtered particles are not formed on the plastic substrates A, B, and C. The thickness of the thin film can be made uniform, and a magneto-optical disk with good dynamic characteristics can be provided.

In the embodiment, the substrate rotation rack gear 1
Although the movable portion 37 is provided at both ends of the
may be provided only on the front side where the gears begin to engage with each other.

Further, in the embodiment described above, a part of the substrate rotation rack gear 19 is moved, but the present invention is not limited to such a structure. For example, as shown in FIG. 4, the entire substrate rotation rack gear 19 is moved. It may also be configured such that it can move in the thickness direction. In this case, the substrate rotation rack gear 19 is constituted by a single member having spring receiving portions 58 at both ends thereof, and the spring receiving portions 58
It is supported by a bracket 51 which also has a spring receiving portion 55 at a position opposite to the bracket 51 . That is, the rack gear 19 for rotating the board is connected to the brackets 1-51 by the compression springs 56 disposed between the spring receiving parts 55 and 58.
On the other hand, it is supported so as to be slidable along the biasing direction of the compression spring 56 by a slide pin 52 with a thick tip passing through a slide hole 59 formed in the bracket 51. There is. Therefore, the gap 6o between the board rotation rack gear 19 and the bracket 51 becomes smaller when the board rotation pinion gear 28 engages with the rack gear 19, so that, for example, the impact at the start of meshing can be buffered. Furthermore, the biasing force of the compression spring 56 can ensure good meshing between the gears.

Further, in the embodiment described above, an example was shown in which one plastic substrate is attached to each of the turntables 6 of the substrate holder 30, and a total of three plastic substrates are attached and transferred while rotating. However, the number of turntables 6 may be increased to further increase productivity. Furthermore, a structure in which the turntables 6 are provided on both sides with a horizontal support plate 7 in between, that is, sputtering It can also be adopted in the case of a double-sided film forming apparatus that uses a substrate holder that can simultaneously form films on both sides of the chamber and has sputtering cathodes on both sides of the chamber. It goes without saying that 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 around each other to form a film.

It should be noted that the above-mentioned embodiment is not limited to the above-mentioned target material, and it goes without saying that other target materials may be used.The present invention also applies to a sputtering apparatus for manufacturing a magneto-optical disk as in the above-mentioned embodiment. Not only, of course,
It can be widely applied to devices for manufacturing optical disks and magnetic disks, as well as other vapor deposition devices.

〔Effect of the invention〕

As described above, the apparatus of the present invention includes a plurality of vacuum chambers adjacent to each other across a gate valve, and is used to form a thin film on a substrate attached to a substrate holder that is continuously transferred to each of the vacuum chambers. A vacuum transfer device for rotating the substrate, wherein the substrate holder is provided with a transfer rack gear, and the substrate holder is moved by engaging a transfer pinion gear arranged at regular intervals in the vacuum chamber. , the substrate holder is reliably transferred with a transport driving force and is accurately transported. Further, a rotary toothing member is provided that transmits rotational force to a rotatable turntable that holds the substrate, and the rotary toothing member is provided in the vacuum chamber for a certain period of time in at least the film forming region. A rotating rack gear that engages with the member and rotates the rotating gear member is provided, and at least a front end of the rotating rack gear moves elastically in a direction substantially perpendicular to a tangential direction to the rotating gear member. For example, when the rotary toothing member meshes with the rack gear for substrate rotation and starts rotating, the rotational toothing member and the rack gear for substrate rotation are relatively easily engaged. Although a large contact force is generated, the impact caused by the contact force at this time can be buffered by the elastic movement of the rotary toothing member, so that the rotary toothing member and the substrate rotation rack gear are smoothly engaged. Troubles such as gear locking and gear damage due to poor meshing between both gears can be effectively avoided.

Therefore, according to the present invention, for example, in a sputtering apparatus, the gear ratio may be increased to avoid poor meshing between the gears of the rotary toothing member and the rack gear for rotating the substrate and to increase the rotational speed of the turntail. Therefore, even if there are variations in the amount of sputtered particles scattered toward the substrate mounted on the turntable, the thickness of the thin film formed on the substrate can be made uniform. A magneto-optical disk with good characteristics can be provided.

[Brief explanation of the drawing]

FIG. 1 shows a schematic side view of essential parts of an embodiment of the vacuum transfer device of the present invention, FIG. 2 is a schematic plan view showing a drive structure for transferring a substrate holder, and FIG. 2 is an enlarged partially cutaway view of the main part, FIG. 4 is a partially cutaway schematic diagram of the main part of another embodiment, and FIG. 5 is a schematic side view of a conventional continuous sputtering system using a pass-through film forming method. 6 is a schematic plan view of FIG. 5. (Symbols in the diagram) 1...Target, 2...Magnet, 3...
・Cathode body, 4...Power supply for sputtering, 5
... Regulating member, 6... Turntable, 7... Horizontal support plate, 8... Table axis, 9... Pallet, 10... Holder movement motor, 11...
Pulley, 12...Timing belt, 13...
- Feed through 14... Transport pinion gear, 15... Rack gear, 16... Drive shaft, 19... Rack gear for substrate rotation, 20... Gate valve, 21a, 21b, 21c - Sputtering chamber, 22...・
・Exhaust system, 27... Gear, 28... Pinion gear for board rotation,
30... Board holder 31.51... Bracket, 32... Fixing means,
33... Inclined surface, 35.3B, 55.58... Spring receiving recess, 6.56
... Compression spring, 37... Movable part, 9... Support shaft,
40... Stopper, 1... Locking piece, 52
...Slide pin, 9...Slide hole, 60...
·gap. 2nd figure 6

Claims (1)

[Claims] In a vacuum transfer device that includes a plurality of vacuum chambers adjacent to each other across a gate valve, and rotates the substrate when forming a thin film on the surface of the substrate attached to a substrate holder that is continuously transferred to each of the vacuum chambers. , the substrate holder is provided with a transport rack gear, and the transport rack gear is moved by engaging a transport pinion gear arranged at regular intervals in the vacuum chamber, and is rotated by a rotatable turntable that holds the substrate. A table rotation pinion gear for transmitting force is provided, and each vacuum chamber includes a rotation rack gear that continuously engages with and rotates the table rotation pinion gear for a certain period at least in the film forming region. A vacuum conveying device, wherein at least a front end of the rotating rack gear is elastically movable to a side opposite to engagement with the table rotating pinion gear.