Spin coating apparatus

Abstract

The present application provides a spin coating device capable of forming a more uniform coating film. The spin coating device includes: a first rotating disc on which a substrate is placed, comprising a plurality of first magnet portions arranged along the outer periphery; a rotating shaft portion which rotationally drives the first rotating disc; a second rotating disc whose lower surface is opposite to the upper surface of the first rotating disc, and a plurality of second magnet portions which generate an attractive force with the first magnet portions are arranged along the outer periphery; and a support shaft portion which is connected to the second rotating disc and supports the second rotating disc in a manner capable of being rotationally linked with the first rotating disc.

Description

Technical Field

[0001] The present invention relates to a spin coating apparatus capable of forming a film on a substrate by applying a coating to the substrate through spin coating. Background Technology

[0002] Spin coating apparatuses are known (for example, see Patent Documents 1 and 2). These apparatuses include a rotary table that horizontally supports a substrate and an upper rotating plate that rotates integrally with the rotary table. The rotary table and the upper rotating plate are fixed together by a spacer ring and a ring plate provided on the outer peripheral upper surface of the rotary table.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 4-61955

[0006] Patent Document 2: Japanese Patent Application Publication No. 4-100561 Summary of the Invention

[0007] The technical problem that the invention aims to solve

[0008] If spacer rings or plates are present in conventional spin coating apparatuses, their rotation may disrupt the airflow, resulting in uneven coating thickness, or so-called uneven coating. Furthermore, if spacer rings or plates are present, powder mist and particles generated during spin coating may collide with them and bounce back, re-adhering to the substrate, potentially causing defects in the resulting film. Therefore, in the prior art, it is sometimes impossible to obtain a uniform film.

[0009] The purpose of this disclosure is to provide a spin coating apparatus capable of forming a more uniform film.

[0010] Technical solutions for solving technical problems

[0011] The aforementioned technical problem is solved by the present disclosure. That is, the spin coating apparatus of the present disclosure (1) comprises:

[0012] A first rotating disk has a substrate on which a plurality of first magnet portions are disposed on the outer periphery;

[0013] A rotating shaft drives the first rotating disk to rotate.

[0014] The lower surface of the second rotating disk is opposite to the upper surface of the first rotating disk, and a plurality of second magnets are provided on the outer periphery to generate an attractive force with the first magnet.

[0015] The support shaft is connected to the second rotating disk and supports the second rotating disk in a manner that allows it to rotate in conjunction with the first rotating disk.

[0016] Furthermore, the spin coating apparatus of the present invention (2) includes:

[0017] A first rotating disk has a substrate on which a plurality of first magnet portions are disposed on the outer periphery;

[0018] A rotating shaft drives the first rotating disk to rotate.

[0019] The lower surface of the second rotating disk is opposite to the upper surface of the first rotating disk, and a plurality of second magnets are provided on the outer periphery, which generate an attractive force and a repulsive force equal to the attractive force between themselves and the first magnet.

[0020] The support shaft is connected to the second rotating disk and supports the second rotating disk in a manner that allows it to rotate in conjunction with the first rotating disk.

[0021] In addition, in the spin coating apparatus of the present invention (3) according to the spin coating apparatus described in (1) or (2), at least one of the first magnet part and the second magnet part is composed of an electromagnet.

[0022] Invention Effects

[0023] According to this disclosure, a spin coating apparatus capable of forming a more uniform film can be provided. Attached Figure Description

[0024] Figure 1 This is a perspective view schematically representing the spin coating apparatus of the first embodiment.

[0025] Figure 2 It is Figure 1 The spin coating apparatus shown is a cross-sectional view of the first rotating disk, the first magnet section, the second rotating disk, and the second magnet section cut along the longitudinal direction.

[0026] Figure 3 It means to use Figure 1 The diagram shows a perspective view of the spin coating process performed by the spin coating apparatus on the substrate.

[0027] Figure 4 It means Figure 3 A three-dimensional view of the next process after the process shown.

[0028] Figure 5 It means Figure 4 A three-dimensional view of the next process after the process shown.

[0029] Figure 6 It means Figure 5 A three-dimensional view of the next process after the process shown.

[0030] Figure 7 It means Figure 6A three-dimensional view of the next process after the process shown.

[0031] Figure 8 It means Figure 7 A three-dimensional view of the next process after the process shown.

[0032] Figure 9 It means Figure 8 A three-dimensional view of the next process after the process shown.

[0033] Figure 10 It means Figure 9 A three-dimensional view of the next process after the process shown.

[0034] Figure 11 This is a perspective view schematically illustrating the spin coating apparatus of the second embodiment. Detailed Implementation

[0035] Hereinafter, embodiments of the spin coating apparatus of this disclosure will be described with reference to the accompanying drawings. The spin coating apparatus of the present invention does not provide a mechanical connection unit between the first rotating disk and the second rotating disk disposed on its upper side, but uses magnetic force to connect the first rotating disk and the second rotating disk so that they can rotate together, thereby forming a film on the substrate uniformly or with less unevenness relative to the upper surface of the substrate.

[0036] Additionally, the terms "up" or "down" are sometimes used in this specification. "Down" refers to the direction of gravity, and "up" refers to the opposite direction. Furthermore, the term "interlocking rotation" is sometimes used in this specification. However, "interlocking rotation" means that two components can rotate freely relative to each other (or are not mechanically connected), but when one component rotates, the other component also rotates in the same direction accordingly (or is non-mechanically connected).

[0037] [First Implementation Method]

[0038] Reference Figures 1-10 The spin coating apparatus 11 of the first embodiment will be described. Figure 1 and Figure 3 As shown, the spin coating apparatus 11 includes: a first rotating disk 13 on which a substrate 12, which is the object to be processed, is placed; a rotating shaft 14 that supports the first rotating disk 13 from below and drives it to rotate; a second rotating disk 15 whose lower surface 15A is parallel to the upper surface of the first rotating disk 13; a support shaft 16 that suspends the second rotating disk 15 and rotatably supports it; a coating liquid spray nozzle 17; and a control unit 18 that controls the entire spin coating apparatus 11. The second rotating disk 15 is positioned further upward in the vertical direction than the first rotating disk 13.

[0039] The coating liquid ejection nozzle 17 has a front end 17A (lower end) for ejecting the coating liquid. The coating liquid ejection nozzle 17 is connected to a container for storing the coating liquid on the base side opposite to the front end 17A. The coating liquid ejection nozzle 17 can eject the coating liquid from the front end 17A (lower end) side toward the upper surface 12A (top surface) of the substrate 12 by driving a pump (not shown). The coating liquid ejection nozzle 17 is supported, for example, by a robotic arm (not shown), and can move on a first rotating disk 13 (referred to as the "first state" of the coating liquid ejection nozzle 17) or retract from the first rotating disk 13 (referred to as the "second state" of the coating liquid ejection nozzle 17).

[0040] The first rotating disk 13 may be a disk formed from a metal material such as aluminum alloy, but it is not limited to this. A disk formed from other metal materials such as stainless steel may also be used, as well as a disk formed from a non-metallic material. A substrate 12 can be placed at the center of the first rotating disk 13. The first rotating disk 13 includes a first disk body 21 and a plurality of first magnet portions 22 provided on the outer periphery 21A of the first disk body 21. Furthermore, the outer periphery 21A is a strip-shaped (ring-shaped) region formed on the inner side of the outer edge of the first disk body 21 (see reference). Figure 1 The first disk body 21 has a plurality of suction holes (not shown) at its center for adsorbing the substrate 12 it is placed on. The suction holes are connected to a vacuum pump (not shown). The suction mechanism including the vacuum pump is able to adsorb and hold the substrate 12 placed on the first rotating disk 13 through the suction holes.

[0041] The multiple first magnet sections 22 are each made of permanent magnets such as neodymium magnets, but are not limited to this. The first magnet sections 22 may also be made of electromagnets or the like. The first magnet sections 22 are arranged, for example, with the N pole facing upwards. More specifically, as... Figure 2 As shown, the first magnet portion 22 is precisely inserted from below into a hole formed by machining from the lower surface of the first disk body 21, thereby fixing the first magnet portion 22 to the first disk body 21. Alternatively, a fixing member may be provided to prevent the first magnet portion 22 from falling out of the hole. Therefore, the upper surface of the magnet is not exposed on the upper surface of the first disk body 21, thereby allowing the upper surface of the first disk body 21 to be formed flat. In this way, if the upper surface of the first disk body 21 can be made flat, the airflow will not be disturbed during rotation. In addition, the diameter of the first rotating disk 13 is, for example, 100 to 300 mm.

[0042] Multiple first magnet portions 22 are arranged at, for example, 24 locations on the outer periphery 21A of the first rotating disk 13 at uniform intervals (in... Figure 1 In the diagram, only six first magnet sections 22 are shown schematically.

[0043] like Figure 1 As shown, the rotating shaft 14 is a cylindrical rod-shaped component made of a metal material such as steel. The rotating shaft 14 supports the first rotating disk 13 at its upper end. The rotating shaft 14 rotates (self-rotates) by a driving force transmitted from the motor 23 and a reduction gear system (not shown), enabling the first rotating disk 13 to rotate. The rotating shaft 14 is supported by a bearing (not shown) to allow rotation. The motor 23 is, for example, a DC motor, and can rotate at any speed under the control of the control unit 18 (e.g., inverter control, drive voltage control, etc.).

[0044] The control unit 18 includes: a computer (computer) containing an operating unit such as a CPU, RAM, ROM, and keyboard, which can input / store programs; and a control circuit (driver) connected to the computer to directly control the electric motor. The rotating shaft 14 and the first rotating disk 13 can rotate at any speed between 0 rpm and 2000 rpm under the control of the control unit 18.

[0045] The second rotating disk 15 is integrally formed with the support shaft 16 and can rotate integrally with the support shaft 16. Alternatively, the second rotating disk 15 can be mounted on the support shaft 16 in a state where it can rotate freely relative to the lower end of the support shaft 16. The second rotating disk 15 may be made of a metal material such as aluminum alloy, but is not limited to this; it may also be made of other metal materials such as stainless steel, or even a non-metallic material. Driven by a mechanical device (not shown), the second rotating disk 15 can be moved to a position opposite to the upper side of the first rotating disk 13 (this position is referred to as the "first state" of the second rotating disk 15), or moved to a position retracted from the position opposite to the upper side of the first rotating disk 13. For convenience, the state where the second rotating disk 15 is not in the first state is sometimes referred to as the "second state."

[0046] The second rotating disk 15 includes a second disk body 24 and a plurality of second magnet portions 25 disposed on the outer periphery of the second disk body 24. The plurality of second magnet portions 25 are respectively composed of permanent magnets such as neodymium magnets, but are not limited thereto. The second magnet portions 25 may also be composed of electromagnets or the like. The second magnet portions 25 are arranged, for example, with their S pole facing downwards. More specifically, as... Figure 2As shown, the second magnet portion 25 is precisely inserted from above into the hole formed by machining from the upper surface of the second disk body 24, thereby fixing it to the second disk body 24. Alternatively, a fixing member can be provided to prevent the second magnet portion 25 from falling out of the hole. Therefore, the lower surface of the magnet is not exposed on the lower surface of the second disk body 24, thereby allowing the lower surface of the second disk body 24 to be formed flat. In this way, if the lower surface of the second disk body 24 can be made flat, the airflow will not be disturbed during rotation.

[0047] The diameter of the second rotating disk 15 is the same as the diameter of the first rotating disk 13, for example, 100~300mm. Figure 1 As shown, a plurality of second magnet portions 25 are arranged at, for example, at 24 on the outer periphery 24A of the second disk body 24 of the second rotating disk 15 at a uniform spacing (in Figure 1 In the diagram, only six second magnet portions 25 are shown schematically. That is, 24 second magnet portions 25 are arranged corresponding to 24 first magnet portions 22. More specifically, the second magnet portions 25 are provided at positions that overlap with the first magnet portions 22 when viewed from above. That is, the second magnet portions 25 are arranged on a circle with the same radius as the circle where the first magnet portions 22 are located and are concentric, and are arranged at angular intervals that are the same as the angular intervals where the first magnet portions 22 are located. In addition, the outer peripheral portion 24A is a strip-shaped (ring-shaped) area formed on the inner side of the outer edge of the second disk body 24 (see reference). Figure 1 Therefore, when the distance between the first rotating disk 13 and the second rotating disk 15 becomes closer, a predetermined attractive force can be generated between the first magnet part 22 (N pole) and the second magnet part 25 (S pole).

[0048] Furthermore, the attractive force acting between the first magnet portion 22 and the second magnet portion 25 is inversely proportional to the square of the distance between them. Therefore, by adjusting the distance between the first rotating disk 13 and the second rotating disk 15, an optimal attractive force can be achieved between them. When spin-coating the substrate 12, the optimal distance between the upper surface 12A (top surface) of the substrate 12 placed on the first rotating disk 13 and the lower surface 15A of the second rotating disk 15 is, for example, 1 mm to 10 mm.

[0049] The mechanical device includes a lifting mechanism for raising and lowering the second rotating disk 15 and the support shaft 16, and a holding mechanism for fixing the setting height of the support shaft 16. The holding mechanism can be a structure that abuts against a protrusion integrally provided on the support shaft 16 when the support shaft 16 moves to a predetermined position, preventing the support shaft 16 and the second rotating disk 15 from further descending; or it can be a brake that operates to fix the setting height of the support shaft 16 and the second rotating disk 15 by maintaining the height of the support shaft 16. By activating the holding mechanism, the mechanical device can maintain a constant distance between the first rotating disk 13 and the second rotating disk 15, even when the attraction between the first magnet 22 and the second magnet 25 is in effect.

[0050] The support shaft 16 is a cylindrical rod-shaped component made of a metal material such as steel. The support shaft 16 does not have a drive source to generate rotational force and is supported by a bearing (not shown) to be rotatable (able to rotate on its own axis). That is, the support shaft 16 can rotate freely independently of the rotating shaft 14. The support shaft 16 supports the second rotating disk 15 at its lower end to be rotatable. Therefore, the second rotating disk 15, which does not have a drive source, and the support shaft 16 can rotate in conjunction with the rotating first rotating disk 13 by the attraction between the first magnet 22 and the second magnet 25. Furthermore, the second rotating disk 15 and the support shaft 16 are magnetically connected by the attraction between the first magnet 22 and the second magnet 25, and can be driven relative to the first rotating disk 13, which rotates by this connection force. In this embodiment, there is no structure that mechanically connects the first rotating disk 13 and the second rotating disk 15.

[0051] Next, refer to Figures 3-10 The spin coating method for a substrate 12 using the spin coating apparatus 11 of this embodiment will be described.

[0052] like Figure 3 As shown, the control unit 18 places the substrate 12 on the central portion of the first rotating disk 13. The placement of the substrate 12 is performed automatically under the control of the control unit 18 using an arm-shaped mechanical device (not shown). Furthermore, during the process of placing the substrate 12, the second rotating disk 15 is in a state where it retracts from the first rotating disk 13 (second state). The substrate 12 is attracted to the first rotating disk 13 through the suction hole by the suction force of the vacuum pump controlled by the control unit 18 and is held adsorbed on the first rotating disk 13.

[0053] like Figure 4 As shown, the control unit 18 drives a pump (not shown) to perform a pre-discarding spraying operation that discards the dried and viscous coating liquid located at the front end 17A of the coating liquid spraying nozzle 17.

[0054] like Figure 5As shown, the control unit 18 moves the coating liquid spray nozzle 17 onto the first rotating disk 13, spraying the coating liquid 26 onto the substrate 12. After the coating liquid 26 is sprayed, as... Figure 6 As shown, the control unit 18 causes the application liquid spray nozzle 17 to retract from the first rotating disk 13.

[0055] Furthermore, such as Figure 7 As shown, the control unit 18 drives the mechanical device to move the second rotating disk 15 onto the first rotating disk 13. Then, the control unit 18 drives the lifting mechanism of the mechanical device to move the second rotating disk 15 so that the lower surface 15A of the second rotating disk 15 comes to a position (first state) that is a given distance (e.g., 1~10mm) away from the upper surface 12A of the substrate 12 on the first rotating disk 13 in the vertical direction. When the second rotating disk 15 has moved to this position, the holding mechanism acts to fix the position of the second rotating disk 15. In addition, if the distance between the first rotating disk 13 and the second rotating disk 15 is too large, the air between them will not rotate together, so the distance between them is preferably 10mm or less. The distance between the first rotating disk 13 and the second rotating disk 15 can be appropriately adjusted taking into account the rotational speed and acceleration of the first rotating disk 13, the diameter of the first rotating disk 13 and the second rotating disk 15, etc.

[0056] When the second rotating disk 15 is moved to this position, a moderate attractive force exists between the first magnet portion 22 of the first rotating disk 13 and the second magnet portion 25 of the second rotating disk 15, and the second rotating disk 15 is configured to rotate in conjunction with the rotation of the first rotating disk 13 in a first state. In this state, as a high-speed rotation process for determining film thickness, the control unit 18 rotates the rotating shaft portion 14 and the first rotating disk 13 at a speed of, for example, 1500 rpm to 2000 rpm. Subsequently, the second rotating disk 15 and the support shaft portion 16 also rotate in conjunction with the first rotating disk 13 at the same speed. This high-speed rotation process for determining film thickness is performed, for example, for 5 to 15 seconds. At this time, the film thickness is determined based on the rotational speed of the first rotating disk 13 and the rotation time of the second rotating disk 15.

[0057] In this way, since the second rotating disk 15 rotates together with the first rotating disk 13, the air between the first rotating disk 13 and the second rotating disk 15 also rotates in the same direction and at the same speed as the first rotating disk 13, which can reduce the unevenness of film thickness caused by wind noise. In addition, since there is no mechanical connection mechanism between the first rotating disk 13 and the second rotating disk 15, it is possible to reduce the turbulence of airflow caused by the connection mechanism during the high-speed rotation process for determining film thickness, or the poor film formation caused by powder mist generated from the coating liquid 26 on the substrate 12 adhering to the connection mechanism during rotation and then re-adhering to the substrate 12.

[0058] Furthermore, after the high-speed rotation process to determine the film thickness, the control unit 18 reduces the rotation speed of the first rotating disk 13 to 50 rpm to 200 rpm, rotating it at a low speed. After the first rotating disk 13 reaches a low speed, the control unit 18 controls the mechanical device to gradually retract the second rotating disk 15 from the first rotating disk 13 (i.e., the state of the second rotating disk 15 changes from the first state to the second state). At this time, by making the movement of the second rotating disk 15 only vertical, the center position of the second rotating disk 15 will not shift significantly from the center position of the first rotating disk 13, preventing the center positions of the first rotating disk 13 and the second rotating disk 15 from shifting when the second rotating disk 15 returns to the first state. In addition, by gradually retracting the second rotating disk 15, the surrounding environment and airflow of the substrate 12 on the first rotating disk 13 will not change drastically. The process of retracting the second rotating disk 15 from the first rotating disk 13 and making the first rotating disk 13 rotate at a low speed is called the film drying process. During the film drying process, airflow is promoted on the substrate 12 to accelerate film drying. The film drying process is carried out for, for example, 30 seconds to 2 minutes.

[0059] Finally, the control unit 18 stops the rotation of the first rotating disk 13, releases the adsorption and holding of the substrate 12, and picks up the substrate 12 using the arm-shaped mechanical device, thereby completing the spin coating of the substrate 12 using the spin coating device 11.

[0060] In this embodiment, the plurality of first magnet portions 22 and the plurality of second magnet portions 25 are composed of permanent magnets, but at least one of the plurality of first magnet portions 22 and the plurality of second magnet portions 25 may also be composed of an electromagnet. When at least one of the plurality of first magnet portions 22 and the plurality of second magnet portions 25 is composed of an electromagnet, the magnetic force of the electromagnet can be switched on and off by the control unit 18. Thus, after the high-speed rotation process for determining the film thickness is completed, when the second rotating disk 15 is retracted from the first rotating disk 13, the output required by the lifting mechanism of the mechanical device for raising the second rotating disk 15 can be reduced. If the second rotating disk 15 can be moved using a robotic arm with a small output, the robotic arm can be miniaturized and made lighter.

[0061] According to the first embodiment, it can be described as follows. The spin coating apparatus 11 includes: a first rotating disk 13 on which a substrate 12 is placed and includes a plurality of first magnet portions 22 disposed along its outer periphery; a rotating shaft portion 14 that drives the first rotating disk 13 to rotate; a second rotating disk 15 whose lower surface 15A faces the upper surface 12A of the first rotating disk 13 and has a plurality of second magnet portions 25 disposed along its outer periphery that generate attraction between the second magnet portions 22 and the first magnet portions 22; and a support shaft portion 16 connected to the second rotating disk 15 and supporting the second rotating disk 15 in a manner that allows it to rotate in conjunction with the first rotating disk 13.

[0062] According to this structure, there is no need to provide a mechanically based connecting mechanism between the first rotating disk 13 and the second rotating disk 15. This reduces film unevenness caused by airflow turbulence resulting from the connecting mechanism. Furthermore, powder mist will not adhere to the connecting unit. Moreover, powder mist adhering to the connecting mechanism can be prevented from re-adhering to the substrate. This reduces film deposition defects. In addition, since there is no drive source on the second rotating disk 15 side, not only is the device structure simplified, but dust and heat generation are also prevented in the upper part of the device, allowing for cleaning of the upper space of the substrate 12 and further improving film quality.

[0063] In this embodiment, at least one of the first magnet part 22 and the second magnet part 25 may also be composed of an electromagnet.

[0064] According to this structure, when the second rotating disk 15 is separated from the first rotating disk 13 after spin coating is completed, the magnetic force of the electromagnet in either the first magnet portion 22 or the second magnet portion 25 can be cut off, eliminating the influence of the attractive force acting between them, thus making it easy to separate the second rotating disk 15. This reduces the force required for the mechanical device used to separate the second rotating disk 15, thereby simplifying the overall structure of the device.

[0065] Next, a modified embodiment of the first embodiment described above will be described. In the following embodiments, the parts that differ from the first embodiment will be described, while the parts that are common to the first embodiment will be omitted.

[0066] [Second Implementation]

[0067] Reference Figure 11 The spin coating apparatus 11 of the second embodiment will be described. In this embodiment, the structure of the first magnet part 22 is different from that of the first embodiment, but the other parts are the same as those of the first embodiment.

[0068] In this embodiment, a plurality of first magnet portions 22 are made of permanent magnets such as neodymium magnets, and are arranged at uniform intervals, for example, at 24 locations on the outer periphery 21A of the first rotating disk 13. Figure 11 (In the illustration, only six first magnet portions 22 are shown.) Similar to the first embodiment, the first magnet portions 22 may also be composed of electromagnets or the like. The method for fixing the plurality of first magnet portions 22 relative to the first disk body 21 is the same as in the first embodiment.

[0069] Of the 24 first magnet sections 22, half, or 12, are arranged with their N poles facing upwards, and the remaining half, or 12, are arranged with their S poles facing upwards. The arrangement of the first magnet sections 22 with their N poles facing upwards and the first magnet sections 22 with their S poles facing upwards is arbitrary. For example, the first magnet sections 22 with their N poles facing upwards and the first magnet sections 22 with their S poles facing upwards can be alternately arranged on the outer peripheral portion 21A, or two first magnet sections 22 with their N poles facing upwards can be arranged consecutively followed by two first magnet sections 22 with their S poles facing upwards, etc.

[0070] On the other hand, the structure and arrangement of the 24 second magnet portions 25 are the same as in the first embodiment, with the S pole facing downwards. Therefore, 12 of the second magnet portions 25 generate an attractive force with the first magnet portion 22 with the N pole facing upwards. The remaining 12 second magnet portions 25 generate a repulsive force with the first magnet portion 22 with the S pole facing upwards. Similar to the first embodiment, the second magnet portions 25 can also be constructed from electromagnets or the like.

[0071] The mechanical device includes a lifting mechanism for raising and lowering the second rotating disk 15 and the support shaft 16. Similar to the first embodiment, the mechanical device can move the second rotating disk 15 to a position opposite the first rotating disk 13 (the "first state" of the second rotating disk 15) to a distance of, for example, 1mm to 10mm above the first rotating disk 13, or to a position retracted from the position opposite the first rotating disk 13 (the "second state" of the second rotating disk 15). However, in this embodiment, since both attraction and repulsion act simultaneously, when the second rotating disk 15 approaches the first rotating disk 13, the second rotating disk 15 is not stretched relative to the first rotating disk 13, and when the second rotating disk 15 moves away from the first rotating disk 13, no attraction force is applied. Therefore, a large force is not required when moving the second rotating disk 15 away from the first rotating disk 13. The mechanical device may omit the same holding mechanism as in the first embodiment, or it may have the same holding mechanism as in the first embodiment, or it may be an auxiliary component that can maintain the position of the support 16 to a certain extent even if a holding mechanism is provided.

[0072] That is, in this embodiment, when the second rotating disk 15 is in the first state, the distance between the upper surface 12A (top surface) of the substrate 12 and the lower surface 15A of the second rotating disk 15 is, for example, 1mm to 10mm. The distance between the first magnet portion 22 and the second magnet portion 25, the number of the first magnet portion 22 and the second magnet portion 25, and the strength of the magnet determined by the number of the first magnet portion 22 and the second magnet portion 25 are designed in a way that balances the attraction and repulsion between the first magnet portion 22 and the second magnet portion 25 at this position.

[0073] Next, the spin coating method for the substrate 12 using the spin coating apparatus 11 of this embodiment will be described.

[0074] The control unit 18 places the substrate 12 on the central portion of the first rotating disk 13. The placement of the substrate 12 is performed automatically under the control of the control unit 18 using an arm-shaped mechanical device (not shown). Furthermore, during the substrate placement process, the second rotating disk 15 is in a state where it retracts from the first rotating disk 13 (second state). The substrate 12 is attracted to the first rotating disk 13 through a suction hole by the suction force of a vacuum pump controlled by the control unit 18 and is held adsorbed on the first rotating disk 13.

[0075] The control unit 18 drives a pump (not shown) to perform a pre-discarding spraying action that discards the dried and viscous coating liquid located at the front end 17A of the coating liquid spraying nozzle 17.

[0076] The control unit 18 moves the coating liquid spray nozzle 17 onto the first rotating disk 13 to spray the coating liquid 26 onto the substrate 12. After spraying the coating liquid 26, the control unit 18 retracts the coating liquid spray nozzle 17 from the first rotating disk 13.

[0077] Then, the control unit 18 drives the mechanical device to move the second rotating disk 15 onto the first rotating disk 13. Next, the control unit 18 drives the lifting mechanism of the mechanical device to move the second rotating disk 15 so that its lower surface 15A is positioned a given distance (e.g., 1-10 mm) away from the upper surface 12A of the substrate 12 on the first rotating disk 13 in the vertical direction (first state). If a holding mechanism is provided, it activates when the second rotating disk 15 has moved to this position. The holding mechanism fixes the position of the second rotating disk 15 at its height.

[0078] When the second rotating disk 15 is moved to this position, an attractive force acts between the first magnet portion 22 (N pole) of the first rotating disk 13 and the second magnet portion 25 (S pole) of the second rotating disk 15, causing the second rotating disk 15 to rotate in conjunction with the rotation of the first rotating disk 13. Furthermore, in the first embodiment where only an attractive force acts, the mechanism for maintaining the first state requires a holding force equal to that attractive force. In contrast, in this embodiment, since both attractive and repulsive forces act, the mechanism for maintaining the first state can be simplified.

[0079] In this state, as part of the high-speed rotation process for determining film thickness, the control unit 18 rotates the rotating shaft 14 and the first rotating disk 13 at a speed of, for example, 1500 rpm to 2000 rpm. Simultaneously, the second rotating disk 15 and the support shaft 16 also rotate in conjunction with the first rotating disk 13 at the same speed. The high-speed rotation process for determining film thickness is performed, for example, for 5 to 15 seconds. During this time, the film thickness is determined based on the rotational speed and rotation time of the first rotating disk 13 and the second rotating disk 15.

[0080] In this way, since the second rotating disk 15 rotates together with the first rotating disk 13, the air between the first rotating disk 13 and the second rotating disk 15 also rotates in the same direction and at the same speed as the first rotating disk 13, which can reduce the unevenness of film thickness caused by wind noise. In addition, since there is no mechanical connection mechanism between the first rotating disk 13 and the second rotating disk 15, it is possible to reduce the turbulence of airflow caused by the connection mechanism during the high-speed rotation process for determining film thickness, or the poor film formation caused by powder mist generated from the coating liquid 26 on the substrate 12 adhering to the connection mechanism during rotation and then re-adhering to the substrate 12.

[0081] Furthermore, after the high-speed rotation process for determining the film thickness, the control unit 18 reduces the rotation speed of the first rotating disk 13 to 50 rpm to 200 rpm, rotating it at a low speed. After the first rotating disk 13 reaches a low speed, the control unit 18 controls the mechanical device to gradually retract the second rotating disk 15 from the first rotating disk 13 (i.e., the state of the second rotating disk 15 changes from the first state to the second state). At this time, by making the movement of the second rotating disk 15 only up and down, the center position of the second rotating disk 15 will not shift significantly from the center position of the first rotating disk 13, preventing the center positions of the first rotating disk 13 and the second rotating disk 15 from shifting when the second rotating disk 15 returns to the first state. In addition, by gradually retracting the second rotating disk 15, the surrounding environment and airflow of the substrate 12 on the first rotating disk 13 will not change drastically. The process of retracting the second rotating disk 15 from the first rotating disk 13 and making the first rotating disk 13 rotate at a low speed is called the film drying process. During the film drying process, airflow is promoted on the substrate 12 to accelerate film drying. The film drying process is carried out for, for example, 30 seconds to 2 minutes.

[0082] Finally, the control unit 18 stops the rotation of the first rotating disk 13, releases the adsorption and holding of the substrate 12, and picks up the substrate 12 using the arm-shaped mechanical device, thereby completing the spin coating of the substrate 12 using the spin coating device 11.

[0083] According to this embodiment, in addition to the effects described in the first embodiment, the spin coating apparatus 11 also includes: a first rotating disk 13 on which a substrate 12 is placed, and includes a plurality of first magnet portions 22 disposed along its outer periphery; a rotating shaft portion 14 that drives the first rotating disk 13 to rotate; a second rotating disk 15, the lower surface 15A of which faces the upper surface 12A of the first rotating disk 13, and a plurality of second magnet portions 25 disposed along its outer periphery that generate an attractive force and a repulsive force equal to the attractive force with the first magnet portions 22; and a support shaft portion 16 connected to the second rotating disk 15 and supporting the second rotating disk 15 in a manner that allows it to rotate in conjunction with the first rotating disk 13. According to this structure, since there is no drive source on the side of the second rotating disk 15, not only is the apparatus structure simplified, but dust and heat are also prevented from being generated in the upper part of the apparatus, allowing for cleaning of the upper space of the substrate 12 and further improving the quality of the film. Furthermore, in this embodiment, not only attraction but also repulsion occurs. Therefore, after the high-speed rotation process for determining film thickness is completed, when the second rotating disk 15 is retracted from the first rotating disk 13, the force required for the mechanical device to separate the second rotating disk 15 can be reduced, thereby simplifying the overall structure of the device.

[0084] According to the above structure, the distance between the first rotating disk 13 and the second rotating disk 15 is maintained by the attractive and repulsive forces acting between the plurality of first magnet portions 22 and the plurality of second magnet portions 25, thus simplifying the structure of the holding mechanism compared to the first embodiment. Furthermore, by utilizing the repulsive forces acting between the plurality of first magnet portions 22 and the plurality of second magnet portions 25, when the second rotating disk 15 separates from the first rotating disk 13 at the end of high-speed rotation determined by the film thickness, the influence of the attractive forces acting between them can be reduced compared to the first embodiment. Therefore, the second rotating disk 15 can be easily separated from the first rotating disk 13. This reduces the force required for the mechanical device used to separate the second rotating disk 15, thereby simplifying the overall structure of the device.

[0085] In the second embodiment, both the plurality of first magnet portions 22 and the plurality of second magnet portions 25 are composed of permanent magnets, but at least one of the plurality of first magnet portions 22 and the plurality of second magnet portions 25 may also be composed of an electromagnet. When at least one of the plurality of first magnet portions 22 and the plurality of second magnet portions 25 is composed of an electromagnet, the magnetic force of the electromagnet can be switched on and off by the control unit 18. Furthermore, in this case, the strength of the magnetic force generated by the plurality of first magnet portions 22 and the plurality of second magnet portions 25 can be varied by the control unit 18. Therefore, for example, the effect of gravity acting on the second rotating disk 15 can be absorbed by the repulsive force acting between the first magnet portions 22 and the second magnet portions 25. Therefore, by using a feedback control method or the like to absorb the weight of the second rotating disk 15 with repulsive force, the holding mechanism can be simplified or omitted.

[0086] The above-described embodiments can be further implemented through various substitutions and modifications. Of course, the different embodiments described above can also be appropriately combined to constitute an invention.

[0087] Explanation of reference numerals in the attached figures

[0088] 11: Spin coating device

[0089] 12: Substrate

[0090] 12A: Upper surface

[0091] 13: First rotating disk

[0092] 14: Rotating shaft

[0093] 15: Second rotating disk

[0094] 15A: Lower surface

[0095] 16: Support shaft section

[0096] 22: First magnet section

[0097] 25: Second magnet section

Claims

1. A spin coating apparatus, characterized in that, have: A first rotating disk has a substrate on which a plurality of first magnet portions are disposed on the outer periphery; A rotating shaft drives the first rotating disk to rotate. The lower surface of the second rotating disk is opposite to the upper surface of the first rotating disk, and a plurality of second magnets are provided on the outer periphery to generate attraction between the second magnet and the first magnet. The support shaft is connected to the second rotating disk and supports the second rotating disk in a manner that allows it to rotate in conjunction with the first rotating disk.

2. A spin coating apparatus, characterized in that, have: A first rotating disk has a substrate on which a plurality of first magnet portions are disposed on the outer periphery; A rotating shaft drives the first rotating disk to rotate. The lower surface of the second rotating disk is opposite to the upper surface of the first rotating disk, and a plurality of second magnets are provided on the outer periphery, which generate an attractive force and a repulsive force equal to the attractive force between themselves and the first magnet. The support shaft is connected to the second rotating disk and supports the second rotating disk in a manner that allows it to rotate in conjunction with the first rotating disk.

3. The spin coating apparatus according to claim 1 or 2, characterized in that, At least one of the first magnet part and the second magnet part is composed of an electromagnet.

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