Coating device

Abstract

Provided is a coating device that suppresses breakage of a substrate.　A coating device (400) is configured so that: a substrate is caused to float on floating stages (420, 460) and a coating stage (440) and thereby be conveyed thereon; and a processing liquid is applied to the substrate on the coating stage (440). The floating stages (420, 460) are disposed on the upstream side and / or the downstream side of the coating stage (440) in the conveyance direction of the substrate. The coating device (400) comprises: measuring instruments (430, 450, 429, 449) for obtaining measured values corresponding to distances between the upper surface of the coating stage (440) and the upper surfaces of the floating stages; and a controller for controlling an actuator for driving the coating stage (440) in the normal direction of the upper surface of the coating stage such that the measured values are within a predetermined range.

Description

Coating Equipment

[0001] The present invention relates to a coating apparatus that coats a substrate with a processing liquid while floating and transporting the substrate.

[0002] The manufacturing process of liquid crystal displays and the like includes a step of applying a treatment liquid such as a resist liquid to a glass substrate, etc. A known coating device used in this coating step is configured to transport the substrate while floating it (floating transport), and to eject the treatment liquid from a nozzle located on a floating stage onto the substrate during transport, thereby forming a coating film on the substrate.

[0003] The levitation stage is provided with a mixture of multiple air outlets for ejecting air and multiple suction ports for sucking air in. By controlling the balance between the pressure of the air ejected from the outlets and the suction force of the suction ports, the height to which the substrate is levitated can be controlled to a predetermined height.

[0004] Literature 1 and Literature 2 describe dividing a levitation stage into multiple separable stage blocks. The divided stage blocks include a rough levitation region and a precision levitation region. The rough levitation region has a large number of nozzles arranged at a certain density or in a certain arrangement pattern. The precision levitation region has a large number of nozzles and suction ports arranged at a certain density or in a certain arrangement pattern.

[0005] JP 2012-182308 A JP 2012-195403 A

[0006] Maintaining a flush top surface of the levitation stage is an extremely important factor in preventing damage to the substrate being transported. For example, if the top surface of the levitation stage is not flush, meaning there are steps between the stage blocks, the substrate may get caught on these steps, which can damage the substrate.

[0007] When the coating device is installed, it is installed so that the top surface of the levitation stage is flush, for the reasons mentioned above. Generally, if the top surface of the levitation stage becomes non-flush, it is necessary to readjust the height of each stage block so that the top surface of the levitation stage is flush again.

[0008] The inventors of the present application have discovered a new, previously unknown cause of the generation of a step between stage blocks. This cause, which will be described in detail later, is that the floor surface partially sinks over time when the coating device is installed on the floor. This causes a step between the stage blocks, and this step increases over time. As the step increases, the substrate being levitated and transported can get caught on the step, causing problems such as damage to the substrate.

[0009] The present invention has been made to solve the above-mentioned problems, and its main purpose is to prevent damage to the levitated and transported substrate by preventing the levitated and transported substrate from getting caught on steps on the levitation stage.

[0010] The coating device of the present invention floats and transports a substrate above a floating stage and a coating stage, and applies a processing liquid to the substrate on the coating stage.The floating stage is positioned at least on either the upstream or downstream side of the coating stage in the substrate transport direction, and the coating device is equipped with a measuring instrument that determines a measurement value corresponding to the distance between the upper surface of the floating stage and the upper surface of the coating stage, and a controller that controls an actuator that drives the coating stage in a direction normal to the upper surface of the coating stage so that the measurement value is within a predetermined range.

[0011] According to the present invention, by obtaining a measurement value corresponding to the distance between the upper surface of the levitation stage and the upper surface of the coating stage, it is possible to detect the step between the levitation stage and the coating stage before the substrate gets caught on the step. When the measurement value exceeds a predetermined range and before the substrate gets caught on the step, the actuator drives the coating stage, thereby reducing the distance between the upper surfaces of the levitation stage and the coating stage, thereby reducing the step. This prevents the substrate from getting caught on the step between the levitation stage and the coating stage, and prevents damage to the substrate being levitated and transported.

[0012] FIG. 1 is a perspective view of the coating device. FIG. 2 is a side view of the coating device. FIG. 3 is a diagram showing the sinking of the coating stage. FIG. 4 is a diagram showing the main parts of the coating stage. FIG. 5 is a schematic diagram showing a second measuring device. FIG. 6 is a diagram showing the coating stage as seen from below. FIG. 7 is a diagram showing the sinking of the support part. FIG. 8 is a flowchart showing a method for compensating for the height of the floating stage. FIG. 9 is a block diagram showing the structure of a controller.

[0013] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The following description of the preferred embodiment is merely exemplary in nature and is not intended to limit the present invention, its applications, or its uses. In addition, in Figures 1 to 7, elements having the same last two digits of the reference numerals correspond to each other.

[0014] 1 shows a coating apparatus 100 that coats a treatment liquid on a substrate S. The coating apparatus 100 includes a first stage 120, a coating stage 140, a second stage 160, and a coating unit 180. The first stage 120, the coating stage 140, and the second stage 160 are configured to float and transport the substrate S. The substrate S is, for example, a glass substrate for a liquid crystal display.

[0015] The substrate S is floated and transported by the upper surfaces of the first stage 120, the coating stage 140, and the second stage 160. The substrate S is transported in the order of the first stage 120, the coating stage 140, and the second stage 160. Therefore, in Fig. 1, the left side is the upstream side in the transport direction of the substrate S, and the right side is the downstream side in the transport direction of the substrate S. When the substrate S is transported to the coating stage 140, a treatment liquid is coated on the upper surface.

[0016] For example, a plurality of air ejection holes (not shown) and a plurality of air suction holes (not shown) are provided on the upper surfaces of the first stage 120, the coating stage 140, and the second stage 160. A pipe for supplying compressed air is connected to the ejection holes, and a pipe for supplying vacuum pressure is connected to the suction holes, and vacuum pressure is supplied.

[0017] The ejection holes generate pressure by compressed air that pushes the substrate S upward. This pressure that pushes the substrate S upward is sometimes referred to as positive pressure. The suction holes generate pressure by vacuum pressure that pulls the substrate S downward. This pressure that pulls the substrate S downward is sometimes referred to as negative pressure. By controlling the balance between these positive and negative pressures, the substrate S is floated at a predetermined height above the first stage 120, the coating stage 140, and the second stage 160.

[0018] The levitated substrate S is transported horizontally from left to right in Fig. 1 by, for example, a transport means. The transport means moves the substrate S along the transport direction by, for example, sucking the side surfaces of the substrate S from both sides.

[0019] A treatment liquid is applied to the upper surface of the transported substrate S by the coating unit 180 on the coating stage 140. The treatment liquid is, for example, a resist liquid. The coating unit 180 is equipped with, for example, a nozzle (not shown) having a slit-shaped outlet for discharging the treatment liquid. The nozzle is disposed above the coating stage 140 and configured to discharge the treatment liquid downward. Therefore, when the substrate S is on the coating stage 140, the nozzle discharges the treatment liquid, thereby coating the upper surface of the substrate S.

[0020] 2 shows a coating apparatus 200 in which the coating unit 180 of FIG. 1 is omitted. The first stage 220 includes a first plate 212 serving as a floating plate, which is configured to include the upper surface of the first stage 220. The coating stage 240 includes a coating plate 232 serving as a floating plate, which is configured to include the upper surface of the coating stage 240. The second stage 260 includes a second plate 252 serving as a floating plate, which is configured to include the upper surface of the second stage 260.

[0021] That is, the upper surface of the first stage 220 is the upper surface of the first plate 212, the upper surface of the coating stage 240 is the upper surface of the coating plate 232, and the upper surface of the second stage 260 is the upper surface of the second plate 252. The coating device 200 is arranged so that the upper surfaces of the first plate 212, the coating plate 232, and the second plate 252 are approximately flush with each other.

[0022] "Approximately flush" here refers to a state in which the first distance between the upper surface of the first stage 220 and the upper surface of the coating stage 240 is within a first range as a predetermined range, and the second distance between the upper surface of the coating stage 240 and the upper surface of the second stage 260 is within a second range as a predetermined range. For example, the first range is 0 μm-100 μm, and the second range is 0 μm-150 μm. In other words, "approximately flush" in this embodiment refers to a state in which the first distance is 100 μm or less, and the second distance is 150 μm or less.

[0023] It is preferable that the film thickness of the treatment liquid applied to the substrate S is uniform. Therefore, it is preferable that the upper surface of the substrate S is approximately horizontal when the treatment liquid is applied. Therefore, the height of the substrate S when it is levitated on the coating stage 240 needs to be controlled more precisely than that of the substrate S when it is levitated on the first stage 220 and the second stage 260. Typically, the height to which the substrate S is levitated on the coating stage 240 is lower than the height to which the substrate S is levitated on the first stage 220 and the second stage 260.

[0024] Specifically, the substrate S is floated by approximately 200 μm on the first stage 220 and the second stage 260. The substrate S is also floated by approximately 30 μm on the coating stage 240. The substrate S thus floated is transported in the order of the first stage 220, the coating stage 240, and the second stage 260.

[0025] If the first distance is large and there is a step between the first stage 220 and the coating stage 240, the substrate S being transported may get caught on this step. Furthermore, if the second distance is large and there is a step between the coating stage 240 and the second stage 260, the substrate S being transported may get caught on this step or collide with the side of the second stage 260. Therefore, by making the top surfaces of the first stage 220, the coating stage 240, and the second stage 260 approximately flush, damage to the substrate S due to getting caught or colliding and delays in substrate transport are suppressed. As a result, the substrate S is transported smoothly. Hereinafter, making the top surfaces of the first stage 220, the coating stage 240, and the second stage 260 approximately flush is referred to as planarization.

[0026] <Subsidence of Floor Surface> Figure 3 shows the coating apparatus 300 installed on the floor surface F. Figure 3(a) shows the coating apparatus 300 in a state where the upper surface of the stage is flattened. The first stage 320, the coating stage 340, and the second stage 360 ​​of the coating apparatus 300 include support portions 314, 334, and 354 that support the first stage 320, the coating stage 340, and the second stage 360, respectively, with respect to the floor surface F.

[0027] The present inventors have found that after the coating device 300 is placed on the floor surface F, the floor surface F partially sinks. Furthermore, the present inventors have found that the amount of sinking of the floor surface F differs between the location where the support portion 334 of the coating stage 340 contacts the floor surface F and the location where the support portions 314, 354 of the first stage 320 and the second stage 360 ​​contact the floor surface F. The amount of sinking of the floor surface F here refers to the amount of downward displacement of the floor surface F at the locations where the support portions 314, 334, 354 contact, based on the height of the floor surface F before the coating device 300 is installed.

[0028] 3B shows the coating device 300 in a state where the floor surface F is sunken at the location where the support portion 334 contacts. Typically, the coating stage 340 is heavier than the first stage 320 and the second stage 360. Therefore, the amount of sunkenness of the floor surface F at the location where the support portion 334 contacts is greater than the amount of sunkenness of the floor surface F at the location where the support portions 314 and 354 contact. For the sake of explanation, FIG. 3 only illustrates the sunkenness of the floor surface F at the location where the support portion 334 contacts, where the amount of sunkenness is greater.

[0029] 3B, the partial sinking of the floor surface F increases a first distance between the upper surface of the first stage 320 and the upper surface of the coating stage 340, and a second distance between the upper surface of the coating stage 340 and the upper surface of the second stage 360. In other words, the partial sinking of the floor surface F causes steps to be formed between the first stage 320 and the coating stage 340, and between the coating stage 340 and the second stage 360.

[0030] 3C shows the coating apparatus 300 in a state in which the support portion 334 of the coating stage 340 is extended in the vertical direction. The support portion 334 of the coating stage 340 is configured to be able to expand and contract in the vertical direction by being driven by an actuator, which will be described later. As the support portion 334 extends in the vertical direction, the coating stage 340 is driven in the normal direction to the upper surface of the coating stage 340.

[0031] In this way, by extending the support portion 334, the height of the coating stage 340 is compensated for by the amount of reduction caused by the sinking of the floor surface F. Therefore, as shown in FIG. 3C, the upper surface of the stage of the coating apparatus 300 is flattened again. In the state in which the upper surface of the stage is flattened, the first distance and the second distance are smaller than the first distance and the second distance, respectively, in the state shown in FIG. 3B. In other words, the step between the first stage 320 and the coating stage 340 and the step between the coating stage 340 and the second stage 360 ​​are reduced.

[0032] <Measuring Instruments> Figure 4 shows the main components of the coating apparatus 400. The coating apparatus 400 includes a measuring instrument and a reference measuring instrument. The measuring instrument is configured to determine measurement values ​​corresponding to the distances between the upper surfaces of the first stage 420 and the second stage 460 and the upper surface of the coating stage 440, and to output the measurement values. The measuring instruments include a first measuring instrument 430 that determines a first measurement value corresponding to a first distance between the upper surface of the first stage 420 and the upper surface of the coating stage 440, and a second measuring instrument 450 that determines a second measurement value corresponding to a second distance between the upper surface of the coating stage 440 and the upper surface of the second stage 460.

[0033] The reference measuring device is configured to output a reference value that is not affected by changes in the distance between the upper surfaces of the first stage 420 and the second stage 460 and the upper surface of the coating stage 440. "Not affected by changes in the distance between the upper surfaces of the first stage 420 and the second stage 460 and the upper surface of the coating stage 440" as used herein means that the effect of changes in this distance on the reference value is negligibly small. The reference measuring devices include a first reference measuring device 429 that is disposed near the first measuring device 430 and determines a first reference value, and a second reference measuring device 449 that is disposed near the second measuring device 450 and determines a second reference value.

[0034] The first measuring device 430 is configured to first determine a first measurement value and then determine a first distance based on the determined first measurement value. The first measuring device 430 includes a first sensor 422 and a first target 424.

[0035] The first sensor 422 and the first target 424 are provided to detect the amount of vertical displacement of the application stage 440 relative to the first stage 420. The first measuring device 430 detects this amount of displacement as a first measurement value.

[0036] The first measuring device 430 is configured to output a first measurement value by measuring the distance between the first sensor 422 and the first target 424. The first sensor 422 may be, for example, a sensor such as an optical sensor, a laser sensor, an eddy current sensor, a differential transformer sensor, an ultrasonic sensor, etc. The first target 424 is appropriately selected depending on the type of sensor so that the distance between the first sensor 422 and the first target 424 can be measured.

[0037] In this embodiment, the first sensor 422 is fixed to the coating stage 440 so as to be located below the coating plate 432. Here, "below the coating plate 432" refers to an area below the lower surface of the coating plate 432 and above the floor surface F. Here, "located below the coating plate 432" is not limited to a position overlapping with the coating plate 432 in a top view. In this embodiment, the first sensor 422 is disposed so as to overlap with the first plate 412 in a top view.

[0038] The first target 424 is fixed to the first stage 420 so that a first measurement value can be obtained. The first target 424 is disposed below the first sensor 422 so as to overlap with the first sensor 422 in a top view.

[0039] In this embodiment, the first sensor 422 is an optical sensor. The first target 424 receives and reflects light emitted by the first sensor 422. The first sensor 422 then receives the light reflected by the first target 424. This determines a first measurement.

[0040] 4, the first measuring device 430 is fixed to a region below the application plate 432 and closer to the first stage 420. For this reason, for example, when the floor surface of the application stage 440 on the side closer to the first stage 420 sinks and the first distance increases, the distance between the first sensor 422 and the first target 424 decreases. This change in the distance between the first sensor 422 and the first target 424 corresponds to the first distance.

[0041] The first reference measuring device 429 includes a first reference sensor 426 and a first reference target 428. The first reference sensor 426 and the first reference target 428 are configured to output a first reference value corresponding to the first measurement value in the flattened state. In this embodiment, the first reference sensor 426 and the first reference target 428 are configured so that the first reference value is the same as the first measurement value in the flattened state. A first difference, which is the difference between the first reference value and the first measurement value, corresponds to the first distance.

[0042] The first reference measuring device 429 outputs a first reference value by measuring the distance between the first reference sensor 426 and the first reference target 428. The first reference sensor 426 may be, for example, a sensor such as an optical sensor, a laser sensor, an eddy current sensor, a differential transformer sensor, an ultrasonic sensor, etc. The first reference target 428 is appropriately selected depending on the type of sensor so that the distance between the first reference sensor 426 and the first reference target 428 can be measured.

[0043] In this embodiment, the first reference sensor 426 is fixed to the coating plate 432 of the coating stage 440 so as to be located below the coating plate 432. The first reference target 428 is disposed so as to be located below the first reference sensor 426 so as to overlap with the first reference sensor 426 in a top view, and is fixed to a location other than the coating plate 432 of the coating stage 440.

[0044] Both the first reference sensor 426 and the first reference target 428 are fixed to the coating stage 440. Therefore, even if the floor surface sinks, the distance between the first reference sensor 426 and the first reference target 428 does not change. For this reason, for example, when the upper surfaces of the first stage 420 and the coating stage 440 are substantially flush with each other, by adjusting the first reference value and the first measurement value to be the same in advance, the first measurement value when the upper surface of the stage is flattened can be saved as the first reference value output by the first reference sensor 426.

[0045] Furthermore, the first reference sensor 426 is fixed to the coating plate 432 of the coating stage, and the first reference target 428 is fixed to a location on the coating stage other than the coating plate 432. Therefore, when bending or distortion occurs in the coating plate 432, the distance between the first reference sensor 426 and the first reference target 428 changes, and the first reference value changes. Therefore, the first reference measuring device 429 can detect bending or distortion of the coating plate 432 based on the change in the first reference value.

[0046] In this embodiment, the second measuring device 450 has substantially the same configuration as the first measuring device 430. The second measuring device 450 is configured to first determine a second measurement value and then determine a second distance based on the determined second measurement value. The second measuring device 450 includes a second sensor 442 and a second target 444.

[0047] The second sensor 442 and the second target 444 are provided to detect the amount of vertical displacement of the coating stage 440 relative to the second stage 460. The second measuring device 450 detects this amount of displacement as a second measurement value.

[0048] The second measuring device 450 is configured to output a second measurement value by measuring the distance between the second sensor 442 and the second target 444. The second sensor 442 may be, for example, a sensor such as an optical sensor, a laser sensor, an eddy current sensor, a differential transformer sensor, an ultrasonic sensor, etc. The second target 444 is appropriately selected depending on the type of sensor so that the distance between the second sensor 442 and the second target 444 can be measured.

[0049] In this embodiment, the second sensor 442 is fixed to the coating stage 440 so as to be located below the coating plate 432. In this embodiment, the second sensor 442 is disposed so as to overlap with the coating plate 432 in a top view.

[0050] The second target 444 is fixed to the second stage 460 so that a second measurement value can be obtained. The second target 444 is disposed below the second sensor 442 so as to overlap with the second sensor 442 in a top view. In this embodiment, the second target 444 is fixed to the upper part of the left end of a fixing member 456 that extends leftward from the second stage 460.

[0051] In this embodiment, the second sensor 442 is an optical sensor. The second target 444 receives and reflects the light emitted by the second sensor 442. The second sensor 442 then receives the light reflected by the second target 444. This provides a second measurement.

[0052] 4, the second measuring device 450 is fixed to an area below the application plate 432 and closer to the second stage 460. Therefore, for example, when the floor surface of the application stage 440 on the side closer to the second stage 460 sinks and the second distance increases, the distance between the second sensor 442 and the second target 444 decreases. This change in the distance between the second sensor 442 and the second target 444 corresponds to the second distance.

[0053] The second reference measuring device 449 includes a second reference sensor 446 and a second reference target 448. The second reference sensor 446 and the second reference target 448 are configured to output a second reference value corresponding to the second measurement value in the flattened state. In this embodiment, the second reference sensor 446 and the second reference target 448 are configured so that the second reference value is the same as the second measurement value in the flattened state. A second difference, which is the difference between the second reference value and the second measurement value, corresponds to the second distance.

[0054] The second reference measuring device 449 outputs a second reference value by measuring the distance between the second reference sensor 446 and the second reference target 448. The second reference sensor 446 may be, for example, an optical sensor, a laser sensor, an eddy current sensor, a differential transformer sensor, an ultrasonic sensor, or the like. The second reference target 448 is appropriately selected depending on the type of sensor so that the distance between the second reference sensor 446 and the second reference target 448 can be measured.

[0055] In this embodiment, the second reference sensor 446 is fixed to the coating plate 432 of the coating stage 440 so as to be located below the coating plate 432. The second reference target 448 is disposed so as to be located below the second reference sensor 446 so as to overlap with the second reference sensor 446 in a top view, and is fixed to a location other than the coating plate 432 of the coating stage 440.

[0056] Both the second reference sensor 446 and the second reference target 448 are fixed to the coating stage 440. Therefore, even if the floor surface sinks, the distance between the second reference sensor 446 and the second reference target 448 does not change. For this reason, for example, when the upper surface of the coating stage 440 and the upper surface of the second stage 460 are substantially flush with each other, by adjusting the second reference value and the second measurement value to be the same in advance, the second measurement value when the upper surface of the stage is flattened can be saved as the second reference value output by the second reference sensor 446.

[0057] Furthermore, the second reference sensor 446 is fixed to the coating plate 432 of the coating stage, and the second reference target 448 is fixed to a location on the coating stage other than the coating plate 432. Therefore, when bending or distortion occurs in the coating plate 432, the distance between the second reference sensor 446 and the second reference target 448 changes, and the second reference value changes. Therefore, the second reference measuring device 449 can detect bending or distortion of the coating plate 432 based on the change in the second reference value.

[0058] Figure 5 shows the second measuring device 550 and the second reference measuring device 549, which are circled by two-dot chain lines in Figure 4. As shown in Figure 5, the second sensor 542 and the second reference sensor 546 include a light-emitting element E and a light-receiving element R. Here, the second measurement value and the second reference value when the floor surface sinks will be described using the second measuring device 550 and the second reference measuring device 549. Note that although a description will be omitted, the same applies to the first measurement value and the first reference value.

[0059] 5 shows the second measuring device 550 and the second reference measuring device 549 when the top surface of the coating stage 540 and the top surface of the second stage 560 are flattened. In this embodiment, when flattened, the second sensor 542 and the second reference sensor 546 are arranged so that their vertical positions are the same. Also, in this embodiment, when flattened, the second target 544 and the second reference target 548 are arranged so that their vertical positions are the same. Therefore, when flattened, the second reference value determined by the second reference measuring device 549 is the same as the second measurement value determined by the second measuring device 550.

[0060] For example, if the floor surface where the coating stage 540 is in contact partially sinks, the second sensor 542, the second reference sensor 546, and the second reference target 548 fixed to the coating stage 540 are moved downward. On the other hand, the second target 544 fixed to the fixing member 556 extending to the left from the second stage 560 does not move downward. As a result, the distance between the second sensor 542 and the second target 544 becomes shorter, and the second measurement value becomes smaller. However, the distance between the second reference sensor 546 and the second reference target 548 does not change, and the second reference value does not change.

[0061] <Compensation Method for Planarization> Figure 6 shows the coating stage 640 as seen from below. The coating plate 632 of the coating stage 640 is rectangular. The coating stage 640 includes five support portions 634. The five support portions 634 are provided at the four corners and the center of the lower part of the coating plate 632. That is, these five support portions 634 include two support portions 634 provided in a region closer to the first stage (the region on the left side of the coating stage 640), two support portions 634 provided in a region closer to the second stage (the region on the right side of the coating stage 640), and one support portion 634 provided in a region equidistant from the first stage and the second stage (the central region in the left-right direction of the coating stage 640).

[0062] The support parts 634 are equipped with actuators 670 for compensating for the height of the coating stage 640 when the floor surface sinks. One actuator 670 is provided for each of the five support parts 634. Therefore, the coating stage 640 is equipped with five actuators 670. The support parts 634 are configured to be able to expand and contract in the vertical direction by being driven by the actuators 670. For example, the actuators 670 may be a wedge mechanism, a screw jack, a hydraulic jack, or the like. The actuators 670 may be operated manually or automatically.

[0063] The actuator 670 provided on the support part 634 provided in the region closer to the first stage of the coating stage 640 (the region on the left side of the coating stage 640) is referred to as the first actuator 670. The actuator 670 provided on the support part 634 provided in the region closer to the second stage of the coating stage 640 (the region on the right side of the coating stage 640) is referred to as the second actuator 670. The first actuator 670 and the second actuator 670 have the same configuration.

[0064] When the first actuator 670 is driven and the support portion 634 extends in the vertical direction, the left side of the coating stage 640 is raised. When the second actuator 670 is driven and the support portion 634 extends in the vertical direction, the right side of the coating stage 640 is raised. In this embodiment, for example, by separately driving the first actuator 670 and the second actuator 670, it is possible to raise only one of the right side or the left side of the coating stage 640, or to raise the right side and the left side by different amounts.

[0065] Fig. 7 shows the support part 734. Fig. 7(a) shows the support part 734 in a state where the upper surface of the stage is flattened, as described with reference to Fig. 3(a). The support part 734 is arranged so that its lower end is in contact with the floor surface F. This support part 734 includes an actuator 770 and a third measuring device 790 as a measuring device. The third measuring device 790 is provided near the floor surface of the support part 734. In this embodiment, the actuator 770 is a wedge mechanism.

[0066] The actuator 770 is configured to be able to expand and contract in the vertical direction. As the actuator 770 expands and contracts in the vertical direction, the entire support portion 734 expands and contracts in the vertical direction. The actuator 770 includes a drive portion 762. In this embodiment, the drive portion 762 is a screw. The screw of the drive portion 762 drives a wedge, and the wedge mechanism of the actuator 770 expands and contracts in the vertical direction.

[0067] If the actuator 770 is a screw jack, the driving unit 762 may be a screw or the like. In this case, the actuator 770 can be extended and retracted in the vertical direction by rotating the screw. If the actuator 770 is a hydraulic jack, the driving unit 762 may be a pump, piston, or the like. In this case, the actuator 770 can be extended and retracted in the vertical direction by driving the pump or piston.

[0068] A controller 764 that controls the movement of the drive unit 762 is connected to the drive unit 762. The controller 764 controls the extension and contraction of the actuator 770 by controlling the drive of the drive unit 762. The controller 764 may be any device that can control the movement of the drive unit 762. For example, if the drive unit 762 is a screw, the controller 764 may be configured to control the rotation of the screw. Furthermore, for example, if the drive unit 762 is a pump, a piston, or the like, the controller 764 may be configured to control the drive of the pump or piston.

[0069] In this embodiment, the controller 764 has the functionality to flatten the top surface of the stage without user intervention. For example, this functionality may be implemented by one or more processors and associated memories. The controller 764 controls the actuator 770 based on the measurements and reference values ​​measured by each measuring device to flatten the top surface of the stage.

[0070] In this embodiment, one third measuring device 790 is provided on each of the five support portions 734 of the coating stage 740. Therefore, the coating stage 740 has five third measuring devices 790. These five third measuring devices 790 each output a different value.

[0071] The structure of the third measuring devices 790 is substantially the same as the second measuring device 550 shown in Figure 5. Each of the third measuring devices 790 includes a third sensor 782 and a third target 784.

[0072] The third sensor 782 and the third target 784 are provided to detect the amount of displacement of the coating stage 740 in the vertical direction. The third measuring device 790 is configured to output a third measurement value by measuring the distance between the third sensor 782 and the third target 784. The third sensor 782 may be, for example, a sensor such as an optical sensor, a laser sensor, an eddy current sensor, a differential transformer sensor, or an ultrasonic sensor. The third target 784 is appropriately selected depending on the type of sensor so that the distance between the third sensor 782 and the third target 784 can be measured.

[0073] In this embodiment, the third sensor 782 of the third measuring device 790 is fixed to the support portion 734 of the coating stage 740. The third sensor 782 is disposed at a position at least a predetermined distance away from the support portion 734 via a bracket or the like. For example, the third sensor 782 is disposed near the support portion of the levitation stage via a bracket that extends from the support portion 734 of the coating stage 740 to near the support portion of the levitation stage. The third target 784 is disposed on the floor surface F located below the third target 784 so as to overlap with the third sensor 782 in a top view.

[0074] In this embodiment, the third sensor 782 is an optical sensor. The third target 784 receives and reflects the light emitted by the third sensor 782. The third sensor 782 then receives the light reflected by the third target 784. This provides a third measurement.

[0075] Of the five third measuring devices 790, the third measuring devices 790 of the two support parts 734 provided in regions closer to the first stage of the coating stage 740 may output different third measurement values. The amount of decrease in the third measurement values ​​output by these two third measuring devices 790 corresponds to the amount of increase in the first distance between the top surface of the first stage and the top surface of the coating stage 740 in the vicinity of each of the support parts 734 on which the third measuring devices 790 that output the third measurement values ​​are provided.

[0076] Of the five third measuring devices 790, the third measuring devices 790 of the two support parts 734 provided in regions closer to the second stage of the coating stage 740 each output a different third measurement value. The amount of decrease in the third measurement values ​​output by these two third measuring devices 790 corresponds to the amount of increase in the second distance between the upper surface of the second stage and the upper surface of the coating stage 740 in the vicinity of each of the support parts 734 on which the third measuring devices 790 that output the third measurement value are provided.

[0077] Of the five third measuring devices 790, the third measuring device 790 on the support part 734 provided in the center of the coating stage 740 outputs a third measurement value. The decrease in the third measurement value of this third measuring device 790 corresponds to, for example, bending or distortion of the coating stage 740. Specifically, if the decrease in the third measurement value output by the third measuring device 790 provided in the center of the coating stage 740 is greater than the decrease in the third measurement values ​​output by the other four third measuring devices 790, the coating stage 740 is distorted and bent so that the center is recessed.

[0078] 7A, that is, in a state in which the upper surface of the stage is flattened, the third measurement values ​​output by the respective third measuring devices 790 are the flat-state third measurement values ​​of the respective third measuring devices 790. These flat-state third measurement values ​​are stored in the memory in such a manner that it is possible to distinguish which third measuring device 790 has output the flat-state third measurement value.

[0079] 7B shows the support portion 734 in a state where the floor surface F is sunk at the location where the support portion 734 contacts, as described with reference to FIG. 3B. As the floor surface F partially sunk, the distance between the third sensor 782 of the third measuring device 790 and the third target 784 decreases. Therefore, the third measurement value in this state is smaller than the third measurement value when the surface is flat.

[0080] FIG. 7C shows the support portion 734 of the coating stage 740 in a state in which the support portion 734 is extended in the vertical direction, as described with reference to FIG. 3C. When the floor surface F partially sinks, the controller 764 drives the actuator 770. The actuator 770 is then extended in the vertical direction, and the support portion 734 is extended in the vertical direction. Therefore, the third measurement value becomes larger than in the state shown in FIG. 7B. The coating stage 740, which is supported by the support portion 734, is then driven in the normal direction to the top surface of the coating stage 740.

[0081] Therefore, the upper surface of the stage is flattened by extending the support portions 734 in the vertical direction. At this time, it is preferable that the support portions 734 are extended so that the first measurement value falls within the first range and the second measurement value falls within the second range. The actuators 770 provided on each support portion 734 may be extended in the vertical direction so that the third measurement values ​​of the third measuring devices 790 provided on the support portions 734 become substantially the same as the respective third measurement values ​​when flat.

[0082] In this way, by providing the third measuring device 790 at a position close to the floor surface F, i.e., on the support portion 734, the amount of vertical displacement of the coating stage 740 caused by the floor surface F sinking can be detected more accurately.

[0083] Furthermore, since the third sensor 782 is disposed at a position at least a predetermined distance away from the support portion 734, when the floor surface F sinks at the portion in contact with the support portion 734, the third target 784 can be prevented from sinking along with the floor surface F. Therefore, the amount of vertical displacement of the coating stage 740 caused by the sinking of the floor surface F can be detected more accurately.

[0084] <Automatic Control of Controller> Figure 8 shows an exemplary process 800 that realizes the function of planarizing the top surface of the stage. The controller executes process 800 to control the actuators to planarize the top surface of the stage. For ease of explanation, the third measuring device will be omitted and only the first and second measuring devices will be used in the explanation.

[0085] Process 800 is first performed with the stage top surface flattened (also referred to as a flush state), and various values ​​are acquired from the measuring devices, i.e., the first measuring device and the second measuring device (820). As described above, the first measuring device outputs a first measurement value and a first reference value. The second measuring device outputs a second measurement value and a second reference value. At 820, these values ​​are stored as flush state values.

[0086] Next, the first measurement value is compared with the first reference value, and the second measurement value is compared with the second reference value, respectively, to determine a first difference and a second difference (840). The first difference is the difference between the first measurement value and the first reference value. The second difference is the difference between the second measurement value and the second reference value. As described above, when the floor surface at the location where the application stage contacts sinks, the first difference and the second difference increase. The first difference corresponds to the first distance, and the second difference corresponds to the second distance.

[0087] Next, it is determined whether the first distance is within a first range based on the first difference (860). If it is determined that the first distance is within the first range, it is then determined whether the second distance is within a second range based on the second difference (880). These determinations are performed without user intervention. If it is determined that the first distance is within the first range and the second distance is within the second range, the first and second differences are again determined (840).

[0088] When it is determined that the first measurement value exceeds the first range or when it is determined that the second measurement value exceeds the second range, a controller 910, which will be described later in FIG. 9 , determines a distance by which to drive the coating stage in the normal direction of the top surface of the coating stage based on the first difference or the second difference (870). This distance is determined so that the first difference and the second difference fall within the first range and the second range, respectively. For example, this distance may be the minimum distance at which the first measurement value and the second measurement value fall within the first range and the second range, respectively, or may be a distance that matches the first reference value and the second reference value, respectively.

[0089] After the distance to drive the coating stage is determined, the actuators are driven (890). Each actuator is driven by the determined distance, and the coating device is flush. Then, in process 800, a first differential and a second differential are determined (840).

[0090] <Hardware> Fig. 9 is a block diagram showing the structure of a controller 910 (corresponding to 764 in Fig. 7) having a function of flattening the stage. The controller 910 includes a processor 920, a memory 940, and an input / output unit 960. The processor 920, the memory 940, and the input / output unit 960 are connected via a bus 980.

[0091] The processor 920 executes each process constituting the process 800 shown in Fig. 8. The memory 940 stores computer-readable instructions and parameters. The processor 920 reads the instructions stored in the memory 940 and executes the process 800.

[0092] A sensor 950 and an actuator 970 are connected to the input / output unit 960. In FIG. 9 , the sensor 950 is illustrated as a single block representing all the sensors included in the coating apparatus of this embodiment. For example, the sensor 950 corresponds to the sensors 422, 426, 442, and 446 in FIG. 4 and the sensor 782 in FIG. 7 . Also in FIG. 9 , the actuator 970 is illustrated as a single block representing all the actuators included in the coating apparatus of this embodiment. For example, the actuator 970 corresponds to each of the five actuators 670 in FIG. 6 .

[0093] The input / output unit 960 receives the measurement value and the reference value from the sensor 950. The input / output unit 960 outputs the measurement value and the reference value to the processor 920 and the memory 940. The input / output unit 960 also outputs a control signal to the actuator 970 based on the output of the processor 920. The input / output unit 960 may be incorporated into the processor 920.

[0094] <Software> Processor 920 executes process 800. At 820, processor 920 receives data from input / output unit 960. This data may be, for example, measurements and reference values ​​output by sensor 950. When input / output unit 960 transmits this data to processor 920, it may also transmit the same data to memory 940. Memory 940 stores this data as parameters.

[0095] At 840, processor 920 receives measurements output from sensor 950 via input / output 960 and bus 980. Processor 920 compares the measurements received at 840 with measurements or reference values ​​stored in memory 940 to determine first and second differences.

[0096] At 860 and 880, processor 920 compares the first and second differences with the first and second ranges, respectively. Processor 920 reads the values ​​of the first and second ranges from memory 940. Processor 920 then compares the first and second differences with the first and second ranges, respectively. Processor 920 determines whether the first and second differences are within the first and second ranges, respectively.

[0097] At 870, processor 920 receives data related to the first difference and the second difference from memory 940. Processor 920 determines the distance to drive each actuator 970 based on this data. For example, this data may be a function that converts the first difference and the second difference into the vertical distance by which each actuator 970 is driven. In this case, processor 920 determines the distance by performing a calculation based on the first difference, the second difference, and the function.

[0098] At 890, processor 920 outputs a control signal to actuator 970 via input / output 960. This control signal includes the distance determined at 870. Actuator 970 is driven based on this control signal. Process 800 is repeated by returning control from 980, 890 to 840.

[0099] Each of the various functions in the present disclosure may be implemented by a single element or multiple elements. Conversely, multiple functions may be implemented by a single element. Each function may be implemented by hardware, software, or a combination of hardware and software. The flowcharts in the present disclosure include multiple blocks. The processing of these blocks may be performed serially or in parallel. The order of some of the blocks may also be changed.

[0100] The subject of the device, system, or method disclosed herein includes a computer. The computer executes a program to realize the functions of the subject of the device, system, or method disclosed herein. The computer's main hardware component is a processor that operates according to a program. The processor may be of any type, as long as it can realize the functions by executing the program. The processor may be composed of one or more electronic circuits, including a semiconductor integrated circuit (IC) or large-scale integration (LSI). While ICs and LSIs are used here, the names may vary depending on the degree of integration, and may be referred to as system LSIs, very large-scale integration (VLSIs), or ultra large-scale integration (ULSIs). Field-programmable gate arrays (FPGAs), which are programmed after the LSI is manufactured, or reconfigurable logic devices that can reconfigure the connections within the LSI or set up circuit partitions within the LSI, can also be used for the same purpose. Multiple electronic circuits may be integrated on a single chip or provided on multiple chips. Multiple chips may be integrated into a single device or provided on multiple devices. The program is recorded on a non-transitory recording medium such as a computer-readable ROM, an optical disk, a hard disk drive, etc. The program may be stored in the recording medium in advance, or may be supplied to the recording medium via a wide area communication network including the Internet.

[0101] 3B, if the floor surface F at the portion where the coating stage 340 comes into contact partially sinks, creating a step between the coating stage 340 and the floating stages 320, 360, it was determined that the step had occurred because the substrate S had gotten caught on the step or collided with the upstream side of the second stage. In other words, the occurrence of the step was not known until the substrate S was actually damaged or the speed at which the substrate S was being transported decreased.

[0102] According to the coating apparatus 300 of this embodiment, the measuring device obtains a measurement value corresponding to the distance between the upper surface of the floating stages 320, 360 and the upper surface of the coating stage 340. Therefore, when the first distance exceeds the first range or the second distance exceeds the second range, the actuator compensates for the first distance or the second distance, thereby achieving flattening. This allows flattening before the substrate S is damaged or the transport speed of the substrate S decreases. Therefore, damage to the substrate S can be suppressed.

[0103] Other Embodiments A typical example of a cause of an increase in the first distance and the second distance is when the application stage 340 is heavier than the floating stages 320 and 360, causing the floor surface F to partially sink significantly. However, the cause of a partial large sinking of the floor surface F is not limited to this. For example, even if the floor surface F sinks due to insufficient strength of the floor surface F, the present invention can compensate for the increased first distance and the second distance.

[0104] 4, the first sensor 422, the first reference sensor 426, and the first reference target 428 of the first measuring device 430 are fixed to the coating stage 440, and the first target 424 is fixed to the first stage 420. However, the first sensor 422, the first reference sensor 426, and the first reference target 428 of the first measuring device 430 may be fixed to the first stage 420, and the first target 424 may be fixed to the coating stage 440.

[0105] 4, the second sensor 442, the second reference sensor 446, and the second reference target 448 are fixed to the coating stage 440, and the second target 444 is fixed to the second stage 460. However, the second sensor 442, the second reference sensor 446, and the second reference target 448 of the second measuring device 450 may be fixed to the second stage 460, and the second target 444 may be fixed to the coating stage 440.

[0106] In the embodiment shown in FIG. 4 , one first measuring device 430 and one second measuring device 450 are provided. However, two or more first measuring devices 430 and two or more second measuring devices 450 may be provided. In this case, a plurality of first measurement values ​​and a plurality of second measurement values ​​are obtained. In this case, for example, in order to bring one first measurement value among the plurality of first measurement values ​​into a first range, only the actuator closest to the first measuring device 430 that output the first measurement value may be driven. Furthermore, in order to bring one second measurement value among the plurality of second measurement values ​​into a second range, only the actuator closest to the second measuring device 450 that output the second measurement value may be driven.

[0107] In the embodiment shown in Figure 4, the first measuring device 430 and the first reference measuring device 429 are configured so that the first measurement value and the first reference value are the same when the stage is flattened. However, the first measurement value and the first reference value when the stage is flattened do not have to be the same. For example, the difference between the first measurement value and the first reference value when the stage is flattened may be stored in memory as a flat-state first difference, and in step 860 of Figure 8, it may be determined whether the difference between the flat-state first difference and the first difference is within a first range.

[0108] In the embodiment shown in Figure 4, the second measuring device 450 and the second reference measuring device 449 are configured so that the second measurement value and the second reference value are the same when the stage is flattened. However, the second measurement value and the second reference value when the stage is flattened do not have to be the same. For example, the difference between the second measurement value and the second reference value when the stage is flattened may be stored in memory as a flat-state second difference, and in 880 of Figure 8, it may be determined whether the difference between the flat-state second difference and the second difference is within the first range.

[0109] 4, the first measuring device 430 and the first reference measuring device 429 are provided separately and separated in the left-right direction. However, the first measuring device 430 and the first reference measuring device 429 may be configured as an integrated device. In this case, it is sufficient that one measuring device includes the first sensor 422 and the first reference sensor 426. Furthermore, it is preferable that one measuring device including the first sensor 422 and the first reference sensor 426 is fixed to the application plate 432.

[0110] 4, the second measuring device 450 and the second reference measuring device 449 are provided separately and separated in the left-right direction. However, the second measuring device 450 and the second reference measuring device 449 may be configured as an integrated device. In this case, it is sufficient that one measuring device includes the second sensor 442 and the second reference sensor 446. Furthermore, it is preferable that one measuring device including the second sensor 442 and the second reference sensor 446 is fixed to the application plate 432.

[0111] 5, the second measuring device 550 has a second target 544 provided below the second sensor 542. However, the light-emitting element E of the second sensor 542 may be configured to emit light upward. In this case, the second target 544 is provided above the light-emitting element E. Furthermore, when the second target 544 is provided above the light-emitting element E, the second target 544 may be on the underside of the second stage. This also applies to the first measuring device.

[0112] In the second reference measuring device 549 of the embodiment shown in FIG. 5 , a second reference target 548 is provided below the second reference sensor 546. However, the light-emitting element E of the second reference sensor 546 may be configured to emit light upward. In this case, the second reference target 548 is provided above the light-emitting element E. In this case, the second reference target 548 is fixed to the coating plate 532 of the coating stage 540, and the second reference sensor 546 is fixed to a location other than the coating plate 532 of the coating stage 540. Furthermore, when the second reference target 548 is provided above the light-emitting element E, the second reference target 548 may be on the underside of the coating stage. This also applies to the first reference measuring device.

[0113] 6 includes five support portions 634. However, the number of support portions 634 included in the coating stage 640 does not have to be five. It is preferable that the coating stage 640 is provided with a plurality of support portions 634 so that the coating stage 640 is supported in a balanced manner.

[0114] 7 includes a third sensor 782 and a third target 784. However, the third target 784 may not be provided, and the floor surface F may serve as the third target. In this case, the third sensor 782 may emit light toward the floor surface F, and the floor surface F may reflect this light.

[0115] A display that displays the measurement value or reference value output by the measuring device, or the difference between the measurement value and the reference value, may be disposed near the support portion 734 of the embodiment shown in Fig. 7. This allows the user to manually operate the actuator 770 while checking the measurement value, reference value, and difference.

[0116] The coating device according to the embodiment of the present invention may further include an alarm. The alarm may be connected to the input / output unit 960 shown in FIG. 9 . For example, when the first measurement value exceeds a first range or when the second measurement value exceeds a second range, the processor 920 may output a command to the alarm via the input / output unit 960 to cause the alarm to issue an alarm. The alarm may be, for example, an alarm that emits sound or a display device that displays information. The alarm may be an alarm sound, audio information, text information, or the like. The alarm sound, audio information, text information, or the like may be stored in the memory 940.

[0117] In the above embodiment, the first range is 0 μm to 100 μm, and the second range is 0 μm to 150 μm or less. The specific values ​​of these first and second ranges are merely examples. The first and second ranges may be set so that the substrate does not get caught on the step between the coating stage and the floating stage.

[0118] Substrate S Coating device 100, 200, 300, 400, 500, 600, 700 Floating stage First stage 120, 220, 320, 420 Second stage 160, 260, 360, 460, 560 Coating stage 140, 240, 340, 440, 540, 640, 740 Measuring device First measuring device 430 Second measuring device 450, 550 Third measuring device 790 Actuator 670, 770 Controller 764

Claims

1. A coating apparatus that floats and transports a substrate above a floating stage and a coating stage, and coats the substrate with a treatment liquid on the coating stage, wherein the floating stage is positioned at least on one of the upstream and downstream sides of the coating stage in a transport direction of the substrate, and the coating apparatus comprises: a measuring device that determines a measurement value corresponding to the distance between an upper surface of the floating stage and an upper surface of the coating stage; and a controller that controls an actuator that drives the coating stage in a normal direction to the upper surface of the coating stage so that the measurement value is within a predetermined range.

2. The coating apparatus according to claim 1, wherein the coating stage is heavier than the floating stage.

3. The coating stage includes a coating plate including the upper surface of the coating stage and a support portion that supports the coating plate against a floor surface; the floating stage includes a floating plate including the upper surface of the floating stage and a support portion that supports the floating plate against a floor surface; the measuring instrument includes a sensor and a target, and outputs the measurement value by measuring the distance between the sensor and the target; (i) the sensor is fixed to the coating stage so as to be located below the coating plate, and the target is fixed to the floating stage so as to determine the measurement value, or (ii) the sensor is fixed to the floating stage so as to be located below the floating plate, and the target is fixed to the coating stage so as to determine the measurement value. The coating apparatus described in claim 1.

4. The coating apparatus according to claim 1, wherein the coating stage includes a coating plate including the upper surface of the coating stage, and a support portion that supports the coating plate against a floor surface, and the measuring device is provided near the floor surface of the support portion.

5. The coating device according to claim 3, wherein the sensor is an optical sensor, the target receives and reflects light emitted by the sensor, and the sensor receives the light reflected by the target.

6. The coating device according to claim 1, wherein the actuator is provided in an area of ​​the coating stage closer to the floating stage, and drives the coating stage based on the measurement value.

7. The coating device of claim 1, wherein the controller determines whether the measurement value is within the predetermined range without user intervention, and when the measurement value exceeds the predetermined range, controls an actuator that drives the coating stage in a normal direction to the top surface of the coating stage so that the measurement value falls within the predetermined range.

8. The coating device according to claim 1, further comprising an alarm that issues a warning to a user when the measured value exceeds the predetermined range.

9. The coating apparatus of claim 4, wherein the floating stage includes a floating plate including the upper surface of the floating stage and a support portion that supports the floating plate against a floor surface, and the measuring device provided on the support portion of the coating stage includes a sensor, and the sensor is positioned at a position that is at least a predetermined distance away from the support portion of the coating stage so as to be located in the vicinity of the support portion of the floating stage.

10. The coating apparatus of claim 7, further comprising a reference measuring device that outputs a reference value that is not affected by changes in the distance between the upper surface of the floating stage and the upper surface of the coating stage, and the controller controls the actuator based on the difference between the measurement value and the reference value.

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