Coating liquid recovery device and spin coater

Abstract

To provide a coating liquid recovery device which can recover a coating liquid removed from a coating object while preventing deterioration of the coating liquid during spin coat.SOLUTION: A coating liquid recovery device 10 is attached to a spin coater 1, which supplies a coating liquid W to a surface of a plate X (a coating object) positioned on a rotary table 2 and rotates the plate X to extend the coating liquid W on the surface of the plate X and thereby apply the coating liquid W to the surface of the plate X, and is configured to recover the coaling liquid W removed from an outer edge of the plate X. The coating liquid recovery device 10 includes: a ceramic cylindrical part 11 which is arranged enclosing a table body 21 of the rotary table 2 so that the coating liquid W removed from the outer edge of the plate X adheres to an inner peripheral surface; and a ceramic bottom part 12 provided with an insertion hole, into which a rotary shaft part 22 of the rotary table 2 may be inserted, and disposed at the lower end side of the cylindrical part 11.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a coating liquid recovery device capable of recovering a coating liquid that has come off from a coating treatment target during coating of the coating liquid by a spin coater, and to a spin coater configured to include such a coating liquid recovery device. [Background technology]

[0002] At semiconductor manufacturing sites, a coating liquid is applied to one surface of a wafer using a spin coater when a film is formed on the surface of the wafer. In this coating process, the plate to be coated is rotated by a turntable while the coating liquid is supplied to the surface of the plate, and the coating liquid is spread on the surface of the plate by centrifugal force, thereby applying the coating liquid to the surface of the plate. As an example, the following patent document discloses a spin coater that applies a liquid made of a water-soluble resin (hereinafter also referred to as "coating liquid") to the surface of a semiconductor wafer, optical device wafer, or the like (hereinafter also simply referred to as "wafer") when forming a protective film to prevent adhesion of debris generated during laser processing.

[0003] This spin coater is configured with a spinner table rotated by an electric motor, a liquid supply nozzle that supplies coating liquid to a wafer clamped on the spinner table, a casing that receives coating liquid that splashes from the wafer during spin coating, and a control unit. The casing also has a cylindrical peripheral wall, a disk-shaped bottom wall disposed at the lower end of the peripheral wall, and legs extending from the lower end of the peripheral wall, and the bottom wall is provided with a drain port that communicates with a drain hose. The output shaft of the electric motor passes through a through hole provided in the center of the bottom wall of this casing, and the peripheral wall is positioned and fixed so that it is located to the side of the spinner table disposed at the upper end of the output shaft.

[0004] When applying a coating liquid to a wafer using this spin coater, first, the wafer to be coated is held by a clamp on the spinner table. Next, while rotating the spinner table at a low speed, the coating liquid is supplied to the surface of the wafer from the liquid supply nozzle, and the rotation speed of the spinner table is then increased. At this time, the coating liquid on the wafer is stretched toward the outer edge by centrifugal force, and the coating liquid is applied to the entire surface of the wafer. Furthermore, the excess coating liquid that reaches the outer edge of the wafer leaves the wafer and reaches the peripheral wall of the casing, dripping down the peripheral wall and being discharged from the discharge port in the bottom wall into the drain hose. This completes the coating process of the coating liquid on the wafer surface. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2022-099712 A (Pages 4-10, Figures 1-9) Summary of the Invention [Problem to be solved by the invention]

[0006] However, the configuration of the spin coater disclosed in the above patent document has the following problems to be solved. Specifically, the spin coater disclosed in the above patent document adopts a configuration in which excess coating liquid that has come off from the outer edge of the wafer during spin coating is received by a casing and discharged into a drain hose from an outlet in the bottom wall. In this case, in order to coat the entire area of ​​the coating target (the wafer in the example disclosed in the above patent document) with the coating liquid evenly, it is necessary to supply a sufficient amount of coating liquid onto the coating target. For this reason, during coating processing using this type of spin coater, a very large amount of coating liquid comes off from the coating target, and it is widely practiced to recover and reuse this coating liquid for the purpose of cost reduction, etc.

[0007] In this case, in order to recover and reuse the excess coating liquid that has been removed from the coating treatment target, it is necessary to recover the coating liquid without causing deterioration (alteration), and if deterioration occurs, a complicated process for modifying the coating liquid is required. Meanwhile, at manufacturing sites of semiconductors, etc., not only protective films such as those disclosed in the above patent documents are formed, but also various thin films are formed by spin coaters. For this reason, some of the coating liquids applied by spin coaters contain solvents that corrode metals and resins, and some are composed of strong acidic or strong alkaline liquids.

[0008] Although there is no specific disclosure in the above patent documents, in many spin coaters of this type, the member (casing in the example of the above patent document) that receives the coating liquid that has fallen off the coating treatment target is made of stainless steel or an oil-resistant resin material. Therefore, in a configuration in which a member made of such a material receives and recovers the coating liquid, depending on the type of coating liquid, it is currently difficult to recover the coating liquid without causing deterioration.

[0009] The present invention has been made in consideration of the above problems to be solved, and its main object is to provide a coating liquid recovery device that can recover coating liquid that has detached from a coating treatment target during spin coating without deteriorating the coating liquid, and a spin coater that is configured so that the recovered coating liquid can be reused. [Means for solving the problem]

[0010] In order to achieve the above-mentioned object, the coating liquid recovery device described in claim 1 is a coating liquid recovery device that is attached to a spin coater that supplies a coating liquid to the surface of a coating target positioned on a rotating table and rotates the target to spread the coating liquid on the surface of the target, thereby applying the coating liquid to the surface of the target, and is configured to be capable of recovering the coating liquid that has detached from the outer edge of the target.The coating liquid recovery device is equipped with a ceramic cylindrical portion that is arranged to surround the table body of the rotating table so that the coating liquid that has detached from the outer edge of the target adheres to its inner surface, and a ceramic bottom portion that is provided with an insertion hole through which the rotation shaft portion of the rotating table can be inserted and is arranged on the lower end side of the cylindrical portion.

[0011] The coating liquid recovery device of claim 2 is the coating liquid recovery device of claim 1, wherein the cylindrical portion is configured to include a first cylindrical portion formed of porous ceramics and allowing the coating liquid to pass through, and a second cylindrical portion formed of dense ceramics and restricting the passage of the coating liquid therethrough, and disposed outside the first cylindrical portion.

[0012] The coating liquid recovery device of claim 3 is the coating liquid recovery device of claim 1 or 2, wherein the bottom is configured with a first bottom formed of porous ceramics and allowing the coating liquid to pass through, and a second bottom formed of dense ceramics and restricting the passage of the coating liquid and disposed below the first bottom.

[0013] The spin coater described in claim 4 comprises the coating liquid recovery device described in claim 1, the rotating table, and a coating liquid supplying device that supplies the coating liquid to the surface of the object to be coated, and the coating liquid supplying device is configured to be able to supply the coating liquid recovered by the coating liquid recovery device to the surface of the object to be coated. Effect of the Invention

[0014] The coating liquid recovery device described in claim 1 is attached to a spin coater and configured to recover the coating liquid that has separated from the outer edge of the coating target, and includes a ceramic cylindrical portion that is arranged to surround the table body of the turntable so that the coating liquid that has separated from the outer edge of the coating target adheres to the inner peripheral surface, and a ceramic bottom portion that is arranged on the lower end side of the cylindrical portion and has an insertion hole through which the rotation shaft of the turntable can be inserted.The spin coater described in claim 4 includes a coating liquid recovery device, a turntable, and a coating liquid supplying device that supplies the coating liquid to the surface of the coating target, and the coating liquid supplying device is configured to be able to supply the coating liquid recovered by the coating liquid recovery device to the surface of the coating target.

[0015] Therefore, according to the coating liquid recovery device described in claim 1 and the spin coater described in claim 4, unlike coating liquid recovery devices made of stainless steel or oil-resistant resin material, the cylindrical part and bottom part are made of ceramics, so the coating liquid recovery device (cylindrical part and bottom part) is not corroded and deteriorated by the coating liquid, and the coating liquid is not deteriorated by the elution of the forming material of the coating liquid recovery device from the coating liquid recovery device into the coating liquid, so the coating liquid recovered by the coating liquid recovery device can be reused as it is to be applied to the coating treatment target. This makes it possible to sufficiently reduce the cost required for reusing the coating liquid.

[0016] In the coating liquid recovery device according to claim 2, the cylindrical portion includes a first cylindrical portion formed of porous ceramics that allows the coating liquid to pass through, and a second cylindrical portion formed of dense ceramics that restricts the passage of the coating liquid and is disposed outside the first cylindrical portion. Therefore, according to the coating liquid recovery device according to claim 2 and a spin coater including such a coating liquid recovery device, when the coating liquid passes through the first cylindrical portion, the first cylindrical portion functions as a filter to preferably remove dust and the like from the coating liquid, and the second cylindrical portion that restricts the passage of the coating liquid can preferably prevent the coating liquid from leaking from the coating liquid recovery device.

[0017] In the coating liquid recovery device according to claim 3, the bottom comprises a first bottom formed of porous ceramics through which the coating liquid is permitted to pass, and a second bottom formed of dense ceramics through which the coating liquid is restricted and disposed below the first bottom. Therefore, according to the coating liquid recovery device according to claim 3 and a spin coater equipped with such a coating liquid recovery device, when the coating liquid is allowed to pass through the first bottom, the first bottom functions as a filter to suitably remove dust and the like from the coating liquid, and the second bottom through which the coating liquid is restricted to pass can suitably prevent the coating liquid from leaking from the coating liquid recovery device. [Brief description of the drawings]

[0018] [Figure 1] FIG. 2 is a diagram showing the configuration of a spin coater 1. [Diagram 2] 2 is an explanatory diagram for explaining the structure of a coating liquid recovery device 10. FIG. [Diagram 3] 2 is an explanatory diagram for explaining the structure of a coating liquid recovery device 50. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Hereinafter, embodiments of the "coating liquid recovery device" and the "spin coater" will be described with reference to the accompanying drawings.

[0020] 1 is an example of a "spin coater (spin coating device)" and is configured to be able to apply various coating liquids W (e.g., resist liquids) by a spin coat method (centrifugal coating method) to the surface of a plate X (e.g., a silicon wafer for semiconductor manufacturing), which is an example of a "subject to be coated". Specifically, the spin coater 1 is configured to include a rotating table 2, a coating liquid supply device 3, a control unit 4, and a coating liquid recovery device 10.

[0021] The turntable 2 is an example of a "turntable" and includes a table body 21, a rotating shaft 22, a motor 23, and a pump 24. The table body 21 is an example of a "table body" and is formed in a disk shape as a whole, and as shown in Fig. 2, a recess is formed on the upper surface thereof and a disk 21a is fitted in the recess. In this case, the disk 21a is formed, for example, of a flat plate made of porous ceramic, and when the disk 21a is fitted in the recess, air in a space S21 formed between the disk 21a and the bottom surface of the recess is sucked in by the pump 24, so that the air on the surface side of the disk 21a passes through the disk 21a and is sucked into the space S21, and the plate X or the like can be sucked and positioned by the suction force to the table body 21 (disk 21a).

[0022] 1, the rotating shaft 22 is an example of a "rotating shaft" and is connected to the rotating shaft of a motor 23, with the table body 21 fixed to its upper end. The motor 23 rotates the rotating shaft 22 under the control of the control unit 4, thereby rotating the table body 21 and the plate body X that is adsorbed and fixed thereto. Under the control of the control unit 4, the pump 24 adsorbs and positions the plate body X to the table body 21 by sucking in the air within the space S21 in the table body 21 as described above.

[0023] The coating liquid supplying device 3 is an example of a "coating liquid supplying device" and includes a pipe 31, a pump 32, and a nozzle 33. The pipe 31 is installed so as to be able to supply the coating liquid W in a container 100, which may be, for example, a container in which a manufacturer of the coating liquid W contains the coating liquid W at the time of product shipment, or a dedicated container for transferring the coating liquid W from such a container and storing it, from the container 100 to the nozzle 33. The pump 32 is disposed in the pipe 31, and pumps (pressure-feeds) the coating liquid W in the container 100 to the nozzle 33 under the control of the control unit 4. The nozzle 33 is attached to a moving mechanism (not shown), and is configured so as to be able to supply (drip) the coating liquid W, which is pumped through the pipe 31, to the plate X when the nozzle 33 is positioned above the plate X fixed by suction to the table main body 21.

[0024] The control unit 4 performs overall control of the spin coater 1. Specifically, as described above, the control unit 4 controls the pump 24 to adsorb and fix the plate X to the table body 21. The control unit 4 also controls the motor 23 to rotate the table body 21 (plate X). Furthermore, the control unit 4 controls the pump 32 to send the coating liquid W from the container 100 to the nozzle 33 via the piping 31.

[0025] On the other hand, the coating liquid recovery device 10 is an example of a "coating liquid recovery device configured to be mountable to a spin coater" and is configured to be removably attached to the spin coater 1 so as to be able to receive and recover the coating liquid W that has come off from the outer edge of the plate body X when the coating liquid W is applied to the surface of the plate body X. This coating liquid recovery device 10 is configured with a cylindrical portion 11 and a bottom portion 12. Note that, in the coating liquid recovery device 10 of this example, as an example, the cylindrical portion 11 and the bottom portion 12 are integrally formed and formed into a container shape with an open top.

[0026] The cylindrical portion 11 is an example of a "ceramic cylindrical portion arranged to surround the table body of the rotating table so that the coating liquid separated from the outer edge of the coating treatment target adheres to the inner peripheral surface", and in the coating liquid recovery device 10 of this example, the cylindrical portion 11 is formed in a cylindrical shape. As shown in FIG. 2, the cylindrical portion 11 includes an inner cylindrical portion 11a, which is an example of a "first cylindrical portion", and an outer cylindrical portion 11b, which is an example of a "second cylindrical portion". The inner cylindrical portion 11a is formed in a cylindrical shape of porous ceramics so that the coating liquid W can pass through, and the outer cylindrical portion 11b is formed in a cylindrical shape of dense ceramics so that the permeation of the coating liquid W is restricted. In this case, the inner cylindrical portion 11a is formed so that its inner diameter is sufficiently larger than the outer diameter of the table body 21 and the plate body X, and its outer diameter is slightly smaller than the inner diameter of the outer cylindrical portion 11b.

[0027] The bottom 12 is an example of a "ceramic bottom having an insertion hole through which the rotating shaft of the rotary table can be inserted and disposed at the lower end of the cylindrical part", and in the coating liquid recovery device 10 of this example, the bottom 12 is formed in a disk shape (annular shape having an insertion hole through which the rotating shaft 22 can be inserted at the center). The bottom 12 includes an upper bottom 12a, which is an example of a "first bottom", and a lower bottom 12b, which is an example of a "second bottom". The upper bottom 12a is formed in a disk shape (annular shape) of porous ceramics so that the coating liquid W can pass through, and the lower bottom 12b is formed in a disk shape (annular shape) of dense ceramics so that the permeation of the coating liquid W is restricted. In addition, the coating liquid recovery device 10 of this example is configured so that a space S12 is generated between the upper bottom 12a and the lower bottom 12b when they are stacked.

[0028] In this case, in the coating liquid recovery device 10 of this example, the inner cylindrical portion 11a and the upper bottom portion 12a are formed of porous ceramics with a porosity in the range of 35% to 60% (for example, oriented continuous pore type porous ceramics in which the extension direction of each pore space is oriented in the plate thickness direction: Asuzac Corporation [AZV60], and completely open pore type porous ceramics: Asuzac Corporation [AZPW40]). Also, in the coating liquid recovery device 10 of this example, the outer cylindrical portion 11b and the lower bottom portion 12b are formed of dense ceramics (for example, Asuzac Corporation [AR99.6]).

[0029] 1, the spin coater 1 (coating liquid recovery device 10) of this example has a configuration in which a pipe 13 for discharging the recovered coating liquid W is connected to the bottom 12 (lower bottom 12b), and the discharge of the coating liquid W stored in the space S12 is permitted / regulated by opening and closing an on-off valve 13a disposed in this pipe 13. Also, the spin coater 1 (coating liquid recovery device 10) of this example has a configuration in which, as an example, an open end of the pipe 13 is disposed above a container 100, and the coating liquid W recovered by the coating liquid recovery device 10 and discharged into the pipe 13 is stored in the container 100 and applied to the plate X during a subsequent coating process (the coating liquid W is reused).

[0030] When the coating liquid W is applied to the surface of the plate X by the spin coater 1, first, a transport device (not shown) transports the plate X to be coated with the coating liquid W and places it on the turntable 2 (table body 21). Next, the control unit 4 controls the pump 24 to start suction. At this time, the air in the space S21 in the table body 21 is sucked by the pump 24, so that the air between the table body 21 and the plate X passes through the disk 21a and is sucked into the space S21, and the plate X is adsorbed to the table body 21 (disk 21a) and positioned.

[0031] Next, the control unit 4 controls the motor 23 to rotate the table body 21 at a low speed, and controls the pump 32 to feed (pressure-feed) the coating liquid W from the container 100 to the nozzle 33. At this time, the plate body X is rotated at a low speed together with the table body 21, and the coating liquid W fed through the piping 31 is supplied from the nozzle 33 to the rotation center of the plate body X. Here, in this type of coating device, the coating liquid W is supplied onto the plate body X in an amount sufficiently larger than the amount of the coating liquid W (the coating liquid W constituting the coating film) left on the plate body X after the coating process is completed so that the coating liquid W is evenly applied to the entire area of ​​the plate body X. Next, the control unit 4 controls the motor 23 to rotate the table body 21 at a high speed. At this time, the coating liquid W on the plate body X rotated together with the table body 21 is stretched toward the outer edge of the plate body X by centrifugal force, resulting in a state in which one surface (upper surface) of the plate body X is entirely covered with the coating liquid W (a state in which the coating liquid W is applied to the entire upper surface of the plate body X).

[0032] In addition, the excess coating liquid W that has reached the outer edge of the plate X due to the centrifugal force caused by the rotation of the table body 21 leaves the outer edge of the plate X and scatters toward the side of the plate X as shown by the arrow A in Fig. 2, and adheres to the inner surface of the cylindrical part 11 of the coating liquid recovery device 10 (the coating liquid W scattered from the plate X is received by the coating liquid recovery device 10). In this case, in the coating liquid recovery device 10 of this example, the inner cylindrical part 11a of the cylindrical part 11 is formed of porous ceramics. Therefore, the coating liquid W that has scattered from the plate X and adhered to the inner cylindrical part 11a easily permeates the cylindrical part 11, and the situation in which the adhered coating liquid W leaves the inner cylindrical part 11a (the situation in which the coating liquid W bounces back from the inner cylindrical part 11a) is avoided. This makes it possible to suitably prevent the coating liquid W (droplets of the coating liquid W) that has detached from the outer edge of the plate X from adhering again to the plate X, thereby preventing uneven coating of the coating liquid W on the plate X.

[0033] The coating liquid W adhering to the cylindrical portion 11 (inner cylindrical portion 11a) drips down toward the bottom portion 12 as shown by the arrow B while permeating into the inner cylindrical portion 11a and adhering to the surface (inner surface) of the inner cylindrical portion 11a. At this time, in the coating liquid recovery device 10 of this example, the outer cylindrical portion 11b is formed of dense ceramics on the outside of the inner cylindrical portion 11a and the permeation (permeation) of the coating liquid W is restricted. This prevents the coating liquid W that has permeated (permeated) into the inner cylindrical portion 11a from leaking out of the coating liquid recovery device 10 (cylindrical portion 11). The coating liquid W that has dripped down the cylindrical portion 11 reaches the bottom portion 12. At this time, in the coating liquid recovery device 10 of this example, the upper bottom portion 12a of the bottom portion 12 is formed of porous ceramics, and the lower bottom portion 12b located below it is formed of dense ceramics. Therefore, the coating liquid W that drips down the cylindrical portion 11 permeates through the upper bottom portion 12a, and its permeation through the lower bottom portion 12b is restricted, so that the coating liquid W does not leak out of the coating liquid recovery device 10, but is instead stored in the space S12 between the upper bottom portion 12a and the lower bottom portion 12b.

[0034] Furthermore, when a predetermined time has elapsed since the table body 21 was shifted to high-speed rotation, the control unit 4 controls the motor 23 to stop the rotation of the table body 21. Furthermore, the control unit 4 controls the pump 24 to release the suction of the plate body X to the table body 21 (disk 21a). This completes the coating process of the coating liquid W on the plate body X. Thereafter, the plate body X for which the processing has been completed is transported by a transport device (not shown) to a storage position for the processed plate body X.

[0035] Meanwhile, when the coating liquid W that drips down the cylindrical portion 11 and is stored in the space S12 of the bottom portion 12 as described above passes through the inner cylindrical portion 11a and the upper bottom portion 12a formed of porous ceramics, the inner cylindrical portion 11a and the upper bottom portion 12a act as filters to remove dust attached to the inner cylindrical portion 11a and the upper bottom portion 12a together with the coating liquid W. In addition, in the coating liquid collector 10 of this example, the cylindrical portion 11 (the inner cylindrical portion 11a and the outer cylindrical portion 11b) and the bottom portion 12 (the upper bottom portion 12a and the lower bottom portion 12b) are all formed of ceramics, so that the coating liquid collector 10 is prevented from being corroded by the coating liquid W that comes into contact with the coating liquid collector 10, and the coating liquid W is prevented from being altered due to elution of the constituent materials of the coating liquid collector 10. This makes it possible to immediately reuse the coating liquid W stored in the space S12 for coating another plate X without removing dust from the coating liquid W or carrying out any processing to modify the coating liquid W that has been altered.

[0036] Specifically, when a predetermined amount of coating liquid W is stored in the coating liquid recovery device 10 (within the space S12), the on-off valve 13a is opened. As a result, the coating liquid W stored in the space S12 is discharged from the coating liquid recovery device 10 (space S12) and caused to flow into the container 100 via the piping 13. As a result, a mixture of the coating liquid W contained in the container 100 and the coating liquid W recovered by the coating liquid recovery device 10 and caused to flow through the piping 13 is sent to the nozzle 33 by the pump 32, and this mixture (coating liquid W) is applied to the surface of the plate X during coating processing of another plate X.

[0037] In this manner, the coating liquid recovery device 10 is attached to the spin coater 1 and configured to recover the coating liquid W that has separated from the outer edge of the plate X (subject to be coated), and includes a ceramic cylindrical portion 11 that is arranged surrounding the table body 21 of the turntable 2 so that the coating liquid W that has separated from the outer edge of the plate X adheres to its inner peripheral surface, and a ceramic bottom portion 12 that is provided with an insertion hole through which the rotating shaft portion 22 of the turntable 2 can be inserted and that is arranged on the lower end side of the cylindrical portion 11. The spin coater 1 also includes the coating liquid recovery device 10, the turntable 2, and a coating liquid supplying device 3 that supplies the coating liquid W to the surface of the plate X, and the coating liquid supplying device 3 is configured to be able to supply the coating liquid W recovered by the coating liquid recovery device 10 to the surface of the plate X.

[0038] Therefore, according to this coating liquid recovery device 10 and spin coater 1, unlike a "coating liquid recovery device" made of stainless steel or an oil-resistant resin material, the cylindrical portion 11 and bottom portion 12 are made of ceramics, so that the coating liquid recovery device 10 (cylindrical portion 11 and bottom portion 12) is not corroded and deteriorated by the coating liquid W, and the coating liquid W is not deteriorated by elution of the forming material of the coating liquid recovery device 10 from the coating liquid recovery device 10 into the coating liquid W, so that the coating liquid W recovered by the coating liquid recovery device 10 can be reused as it is to apply it to the plate X. This makes it possible to sufficiently reduce the cost required for reusing the coating liquid W.

[0039] Moreover, in this coating liquid recovery device 10, the cylindrical portion 11 is configured to include an inner cylindrical portion 11a formed of porous ceramics and allowing the coating liquid W to pass therethrough, and an outer cylindrical portion 11b formed of dense ceramics and arranged outside the inner cylindrical portion 11a, restricting the passage of the coating liquid W. Therefore, according to this coating liquid recovery device 10 and spin coater 1, when the coating liquid W passes through the inner cylindrical portion 11a, the inner cylindrical portion 11a functions as a filter to suitably remove dust and the like from the coating liquid W, and the outer cylindrical portion 11b, which restricts the passage of the coating liquid W, can suitably prevent the coating liquid W from leaking from the coating liquid recovery device 10.

[0040] Moreover, in this coating liquid recovery device 10, the bottom 12 is configured to include an upper bottom 12a formed of porous ceramics and allowing the coating liquid W to pass through, and a lower bottom 12b formed of dense ceramics and disposed below the upper bottom 12a, restricting the passage of the coating liquid W. Therefore, according to this coating liquid recovery device 10 and spin coater 1, when the coating liquid W passes through the upper bottom 12a, the upper bottom 12a functions as a filter to suitably remove dust and the like from the coating liquid W, and the lower bottom 12b, which restricts the passage of the coating liquid W, suitably prevents the coating liquid W from leaking from the coating liquid recovery device 10.

[0041] The configurations of the “coating liquid recovery unit” and the “spin coater” are not limited to the above-mentioned examples of the coating liquid recovery unit 10 and the spin coater 1.

[0042] For example, the coating liquid recovery device 50 shown in FIG. 3 is another example of a "coating liquid recovery device configured to be mountable to a spin coater", and is configured to be removably attached to the spin coater 1 in the same manner as the coating liquid recovery device 10 in the above-mentioned example, and to receive and recover the coating liquid W that has come off from the outer edge of the plate body X when the coating liquid W is applied to the surface of the plate body X. Note that components other than the coating liquid recovery device 10 in the spin coater 1 are the same as in this example equipped with the coating liquid recovery device 50, and therefore repeated explanations will be omitted. This coating liquid recovery device 50 is configured to include a cylindrical portion 51 and a bottom portion 52. Note that in the coating liquid recovery device 50 of this example, the cylindrical portion 51 and the bottom portion 52 are formed separately, for example.

[0043] The cylindrical portion 51 is another example of a "ceramic cylindrical portion arranged to surround the table body of the rotating table so that the coating liquid separated from the outer edge of the coating treatment target adheres to the inner peripheral surface", and in the coating liquid recovery device 50 of this example, the cylindrical portion 51 is formed in a cylindrical shape. As shown in FIG. 3, the cylindrical portion 51 includes an inner cylindrical portion 51a, which is another example of a "first cylindrical portion", and an outer cylindrical portion 51b, which is another example of a "second cylindrical portion". The inner cylindrical portion 51a is formed in a cylindrical shape of porous ceramics so that the coating liquid W can pass through, and the outer cylindrical portion 51b is formed in a cylindrical shape of dense ceramics so that the permeation of the coating liquid W is restricted. In this case, the inner cylindrical portion 51a is formed so that its inner diameter is sufficiently larger than the outer diameter of the table body 21 and the plate body X, and its outer diameter is slightly smaller than the inner diameter of the outer cylindrical portion 51b.

[0044] The bottom 52 is another example of a "ceramic bottom having an insertion hole through which the rotating shaft of the rotary table can be inserted and disposed at the lower end side of the cylindrical part", and in the coating liquid recovery device 50 of this example, the bottom 52 is formed in a circular shallow dish shape (an annular shape having an insertion hole through which the rotating shaft 22 can be inserted formed in the center). The bottom 52 includes an upper bottom 52a, which is another example of a "first bottom", and a lower bottom 52b, which is another example of a "second bottom". The upper bottom 52a is formed in a disk shape (annular shape) of porous ceramics to allow the coating liquid W to pass through, and the lower bottom 52b is formed in a disk shape (annular shape) of dense ceramics to restrict the permeation of the coating liquid W. In this case, in the coating liquid recovery device 50 of this example, the outer shape of the bottom 52 is configured to be larger than the outer shape of the cylindrical part 51. Furthermore, the coating liquid recovery device 50 of this embodiment is configured so that when the upper bottom portion 52a and the lower bottom portion 52b are overlapped, a space S52 is generated between them.

[0045] In addition, in the spin coater 1 equipped with this coating liquid recovery device 50, a pipe 13 for discharging the recovered coating liquid W is connected to the bottom 52 (lower bottom 52b), and a configuration is adopted in which the discharge of the coating liquid W stored in the above-mentioned space S52 is permitted / regulated by opening and closing an opening / closing valve 13a arranged in this pipe 13.

[0046] When the coating liquid W is applied to the surface of the plate X by the spin coater 1 equipped with the coating liquid recovery device 50, the plate X transported by a transport device (not shown) is first adsorbed and fixed to the table body 21 (disk 21a) in the same manner as in the coating process by the spin coater 1 equipped with the coating liquid recovery device 10 described above. Next, the table body 21 is rotated at a low speed, and the coating liquid W is fed (pressurized) from the container 100 to the nozzle 33, thereby supplying the coating liquid W to the rotation center of the plate X. Next, the table body 21 is rotated at a high speed, so that the coating liquid W on the plate X is spread toward the outer edge of the plate X by centrifugal force. As a result, the entire surface (upper surface) of the plate X is covered with the coating liquid W (the entire upper surface of the plate X is coated with the coating liquid W).

[0047] At this time, the excess coating liquid W that has reached the outer edge of the plate body X due to the centrifugal force caused by the rotation of the table body 21 leaves the outer edge of the plate body X and scatters toward the side of the plate body X as shown by the arrow A in Fig. 3, and adheres to the inner surface of the cylindrical part 51 of the coating liquid recovery device 50 (the coating liquid W scattered from the plate body X is received by the coating liquid recovery device 50). In this case, in the coating liquid recovery device 50 of this example, the inner cylindrical part 51a at the bottom 52 is formed of porous ceramics. Therefore, the coating liquid W that has scattered from the plate body X and adhered to the inner cylindrical part 51a easily permeates the cylindrical part 51, and the situation in which the adhered coating liquid W leaves the inner cylindrical part 51a (the situation in which the coating liquid W bounces back from the inner cylindrical part 51a) is avoided. This makes it possible to suitably prevent the coating liquid W (droplets of the coating liquid W) that has detached from the outer edge of the plate X from adhering again to the plate X, thereby preventing uneven coating of the coating liquid W on the plate X.

[0048] The coating liquid W adhering to the cylindrical portion 51 (inner cylindrical portion 51a) drips down toward the bottom portion 52 as shown by the arrow B while permeating into the inner cylindrical portion 51a and adhering to the surface (inner surface) of the inner cylindrical portion 51a. At this time, in the coating liquid recovery device 50 of this example, there is an outer cylindrical portion 51b formed of dense ceramics on the outside of the inner cylindrical portion 51a, which restricts the permeation (permeation) of the coating liquid W. This prevents the coating liquid W that has permeated (permeated) into the inner cylindrical portion 51a from leaking out of the coating liquid recovery device 50 (cylindrical portion 51). The coating liquid W that has dripped down the cylindrical portion 51 reaches the bottom portion 52. At this time, in the coating liquid recovery device 50 of this example, the upper bottom portion 52a of the bottom portion 52 is formed of porous ceramics, and the lower bottom portion 52b located below it is formed of dense ceramics. Therefore, the coating liquid W that drips down the cylindrical portion 51 permeates through the upper bottom portion 52a, and its permeation through the lower bottom portion 52b is restricted, so that the coating liquid W does not leak out of the coating liquid recovery device 50, but is instead stored in the space S52 between the upper bottom portion 52a and the lower bottom portion 52b.

[0049] When the coating liquid W dripping down the cylindrical portion 51 and stored in the space S52 of the bottom portion 52 in this way passes through the inner cylindrical portion 51a and the upper bottom portion 52a formed of porous ceramics, the inner cylindrical portion 51a and the upper bottom portion 52a act as filters to remove dust adhering to the inner cylindrical portion 51a and the upper bottom portion 52a together with the coating liquid W. In addition, in the coating liquid collector 50 of this example, the cylindrical portion 51 (the inner cylindrical portion 51a and the outer cylindrical portion 51b) and the bottom portion 52 (the upper bottom portion 52a and the lower bottom portion 52b) are all formed of ceramics, so that it is possible to prevent the coating liquid collector 50 from being corroded by the coating liquid W in contact with the coating liquid collector 50 or the coating liquid W from being altered due to elution of the constituent materials of the coating liquid collector 50. This makes it possible to immediately reuse the coating liquid W stored in the space S52 for coating another plate X without removing dust from the coating liquid W or carrying out any processing to modify the coating liquid W that has been altered.

[0050] In this way, the coating liquid recovery device 50 and the spin coater 1 equipped with the coating liquid recovery device 50 can achieve the same effects as those of the coating liquid recovery device 10 and the spin coater 1 equipped with the coating liquid recovery device 10 described above. In addition, since the coating liquid recovery device 50 has the cylindrical portion 51 and the bottom portion 52 formed separately, it can be manufactured more easily than the coating liquid recovery device 10 in which the cylindrical portion 11 and the bottom portion 12 are integrally formed, and when the cylindrical portion 51 is damaged or soiled, it is possible to continue using the bottom portion 52 and replace only the cylindrical portion 51 with a new cylindrical portion 51, or when the bottom portion 52 is damaged or soiled, it is possible to continue using the cylindrical portion 51 and replace only the cylindrical bottom portion 52 with a new bottom portion 52, so that the cost required for recovery of the coating liquid W can be sufficiently reduced.

[0051] Although the configuration has been described as an example in which the on-off valve 13a is opened when a specified amount of coating liquid W is stored in the space S12, S52 to discharge the coating liquid W from the coating liquid recovery device 10, 50, instead of discharging by manually operating the on-off valve 13a, a configuration can be adopted in which an electromagnetic on-off valve or the like is used as the on-off valve 13a, and the control unit 4 controls the on-off valve 13a to the open state at a predetermined timing to discharge the coating liquid W from the coating liquid recovery device 10, 50. Also, a configuration can be adopted in which the on-off valve 13a is not provided in the piping 13, and the coating liquid W that has reached the space S12, S52 is successively discharged.

[0052] Although the configuration of the coating liquid recovery device 10, 50 having the cylindrical part 11, 51 with the inner cylindrical part 11a, 51a formed of porous ceramics and the outer cylindrical part 11b, 51b formed of dense ceramics has been described as an example, the entire "cylindrical part" can also be formed of dense ceramics. Furthermore, the configuration of the coating liquid recovery device 10, 50 having the bottom part 12, 52 with the upper bottom part 12a, 52a formed of porous ceramics and the lower bottom part 12b, 52b formed of dense ceramics has been described as an example, but the entire "bottom part" can also be formed of dense ceramics. [Explanation of symbols]

[0053] 1 Spin coater 2 Rotating table 3 Coating liquid supply device 4. Control section 10,50 Coating fluid recovery device 11,51 Cylindrical part 11a, 51a Inner cylindrical part 11b, 51b Outer cylindrical part 12,52 bottom 12a,52a Upper bottom 12b,52b Lower bottom 13 Piping 13a On-off valve 21 Table body 21a Disc 22 Rotating shaft 23 Motor 24,32 Pump 31 Piping 33 Nozzle 100 containers S12,S21,S52 space X plate W coating liquid

Claims

1. A coating liquid recovery device is attached to a spin coater that supplies a coating liquid to a surface of a coating target positioned on a turntable and rotates the target to spread the coating liquid on the surface of the target, thereby coating the coating liquid on the surface of the target, and is configured to be capable of recovering the coating liquid that has separated from an outer edge of the target, a ceramic cylindrical portion that is disposed around a table body of the turntable so that the coating liquid that has separated from an outer edge portion of the coating treatment target adheres to an inner peripheral surface of the cylindrical portion; a coating liquid recovery device including a ceramic bottom portion disposed on a lower end side of the cylindrical portion and having a through hole through which a rotation shaft portion of the rotary table can be inserted;

2. The coating liquid recovery device according to claim 1, wherein the cylindrical portion comprises a first cylindrical portion formed of porous ceramics through which the coating liquid can pass, and a second cylindrical portion formed of dense ceramics through which the coating liquid can be restricted and which is disposed outside the first cylindrical portion.

3. The coating liquid recovery device according to claim 1 or 2, wherein the bottom comprises a first bottom formed of porous ceramics through which the coating liquid is permitted to pass, and a second bottom formed of dense ceramics through which the coating liquid is restricted from passing and disposed below the first bottom.

4. a coating liquid recovery device according to claim 1, the turntable, and a coating liquid supplying device that supplies the coating liquid to the surface of the coating treatment target, The coating fluid supplying device is a spin coater configured to be able to supply the coating fluid recovered by the coating fluid recovery device to the surface of the object of coating treatment.

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