JP5081261B2 - Coating device - Google Patents

Description

  The present invention relates to a coating apparatus that applies a processing liquid to a substrate to be processed on a floating stage.

  In a photolithography process in a manufacturing process of a flat panel display (FPD) such as an LCD, a resist solution is applied onto a substrate to be processed (such as a glass substrate) using a long slit nozzle having a slit-like discharge port. A spinless coating method is often used.

  As one form of such a spinless coating method, a substrate floating mechanism is incorporated in the stage for supporting the substrate, and the substrate is floated in the air on this floating stage and conveyed in one horizontal direction (stage longitudinal direction). There is a levitation method in which the resist solution is applied from one end to the other end on the substrate by discharging the resist solution in a strip shape toward the substrate that passes directly below the slit nozzle installed above the stage at a predetermined position in the middle. Are known.

  In such a levitation-type spinless coating method, in order to uniformly form a resist solution coating film on a substrate with a set film thickness, a small gap of usually about 100 μm provided between the discharge port of the slit nozzle and the substrate is used. Is accurately maintained at or near the setpoint.

  In order to satisfy this requirement, a resist coating apparatus that employs a levitation-type spinless coating method simply provides a large number of jet nozzles for jetting high-pressure or positive-pressure gas, such as air, at a predetermined density over substantially the entire surface of the levitation stage. Rather, a suction port for sucking air at a negative pressure is mixed in the ejection port in the application region set as the area immediately below and before and behind the slit nozzle on the floating stage. In the application region, the floating pressure applied to the substrate is finely balanced by balancing the vertical upward pressure applied from the jet port and the vertical downward pressure applied from the suction port with respect to the substrate passing therethrough. The flying height of the substrate is adjusted to a set value (for example, 50 μm) (for example, Patent Document 1).

JP2007-190483A

  Although the resist coating apparatus as described above operates in a clean room, it is often exposed to foreign matters such as fine particles and relatively large particles as well as fine particles. These foreign substances may drift in the atmosphere, be brought in from the outside during maintenance, or may be generated during maintenance work, or may be caused by substrate breakage or film peeling.

  In any case, in the resist coating apparatus that employs the above-described levitation-type spinless coating method, the suction port in the coating area of the levitation stage undesirably sucks foreign matter drifting around it. The suction port may be clogged with foreign matter. When the suction port becomes clogged, the suction port cannot exert a suction force on the substrate passing therethrough.

  Usually, several thousand or more suction ports are provided in the application region of the floating stage. Even if one or two of them are clogged, the whole suction force is not affected at all. However, when about several hundred suction ports are clogged, the whole suction force is remarkably lowered. In addition, even if there are about several tens of clogged suction ports, if they are concentrated in a narrow range, the balance between the buoyant force from the jet port and the attractive force from the suction port is lost in the vicinity, and the substrate flying height is increased. May be locally higher than the set value. If the flying height of the substrate is locally higher than the set value in the coating area (especially immediately below the slit nozzle), the thickness of the resist coating film formed on the substrate fluctuates, reducing the accuracy and reliability of photolithography. Let

  Conventionally, in order to remove the clogging of the suction port in the levitation stage as described above, the levitation stage is disassembled and the suction port is cleaned, or the suction head of an external cleaner is applied to the upper surface of the levitation stage. A method has been adopted in which foreign matter clogged in the mouth is removed by suction from above.

  However, the disassembly and cleaning method is very troublesome and requires a great amount of human labor, and the long work time, that is, the recovery time, is also hated on site. In addition, the method using an external vacuum cleaner easily damages the levitation stage by applying a suction head to the levitation stage, and also requires human work, although not as much as the disassembly cleaning method.

  Conventionally, there has been no means or function for checking whether or not the suction port of the levitation stage is clogged. For this reason, when the film thickness of the resist coating film is affected by clogging of the suction port, it may take a while until the cause is determined. On the other hand, when periodic maintenance by the above-described disassembly cleaning or external cleaning is frequently performed in a short cycle, a great amount of human labor and a reduction in the device operation rate are caused.

  The present invention solves the problems of the prior art as described above, and the operation for removing clogging of the suction port in the levitation stage can be performed automatically and efficiently at any time or in the apparatus. A coating apparatus is provided.

The coating apparatus according to the present invention floats a substrate to be processed by a levitation stage having a first levitation region provided with a mixture of a large number of ejection openings and a large number of suction openings, and the pressure of gas ejected from the ejection openings. Therefore, in order to control the flying height of the substrate by a first air supply unit that supplies a positive pressure gas to the ejection port via a first manifold, and a suction force that sucks the gas into the suction port, A suction exhaust unit that applies a negative pressure to the suction port via a second manifold; a transport mechanism that holds the substrate floating in the air on the levitation stage and transports the substrate so as to pass through the first levitation region; A processing liquid supply unit having a nozzle disposed above the first floating region, and supplying a processing liquid from the nozzle onto the substrate passing through the first floating region; and a suction port To clean the suction And a second air supply unit that supplies a positive pressure gas to the mouth via the second manifold .

  In the above configuration, the foreign matter floating around the levitation stage is undesirably while the suction port provided in the first levitation area of the levitation stage is performing a suction operation (mainly during the coating process). Inhalation may cause clogging of the suction port. However, according to the present invention, when the coating process is paused or during the coating process, the suction / exhaust unit is stopped and the second air supply unit is operated to manually clog the suction port. Can be removed automatically and efficiently.

  According to the coating apparatus of the present invention, the operation for removing the clogging of the suction port in the levitation stage can be automatically and efficiently performed at any time or in the apparatus by the configuration and operation as described above.

It is a schematic plan view which shows the main structures of the resist coating apparatus in one Embodiment of this invention. It is a schematic front view of the substrate conveying direction showing the main configuration of the resist coating apparatus. It is a schematic side view which shows the attachment structure and effect | action of the optical distance sensor of the flying height measuring part in the said resist coating apparatus. It is a figure which shows the structure of the nozzle refresh part in the said resist coating device, and the attachment structure of a planar suction part. It is a block diagram which shows the structure of the control system in the said resist coating apparatus. FIG. 5 is a schematic cross-sectional view showing a state of a coating processing unit when foreign matter is hardly clogged in a suction port of a floating stage in the resist coating apparatus. FIG. 5 is a schematic cross-sectional view showing a state of a coating processing unit when foreign matter is clogged in a suction port of a floating stage in the resist coating apparatus. It is a schematic sectional drawing which shows an effect | action when the 2nd air supply part act | operates in the said resist coating device. It is a figure which shows an effect | action when using a planar adsorption | suction part for the floating stage suction port cleaning in the said resist coating apparatus. It is a figure which shows the modification of the 2nd air supply part in the said resist coating device. It is a pressure waveform figure for demonstrating an effect | action when a compression tank is used for a 2nd air supply part. It is a figure which shows 1 step | paragraph of the system which carries out the time division control of the pressure for the cleaning given to the suction opening of a levitation | floating stage by a 2nd air supply part. It is a figure which shows 1 step | paragraph of the system which carries out the time division control of the pressure for the cleaning given to the suction opening of a levitation | floating stage by a 2nd air supply part.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

  1 and 2 show the main configuration of a resist coating apparatus according to an embodiment of the present invention. FIG. 1 is a schematic plan view, and FIG. 2 is a schematic front view in the substrate transport direction.

  This resist coating apparatus employs a levitation spinless coating method, and as shown in FIG. 1, a levitation stage 10 that floats a substrate to be processed, such as a glass substrate G for FPD, in the air by gas pressure, and the levitation A transport mechanism 12 for transporting the substrate G floating in the air on the stage 10 in the longitudinal direction (X direction) of the floating stage; a slit nozzle 14 for supplying a resist solution to the upper surface of the substrate G transported on the floating stage 10; It has.

The upper surface of the levitation stage 10 is divided into three regions, that is, a carry-in region M _IN , a coating region M _COT, and a carry-out region M _OUT along the substrate transfer direction (X direction). Among these, only a large number of jet nozzles 16 are provided in the carry-in area M _IN and the carry-out area M _OUT with a predetermined density, and many jet _nozzles 16 and suction ports 18 are provided with a predetermined density in the coating area M _COT. It is provided in a mixed manner.

Into the carry-in area _MIN , a substrate G for carrying the substrate G before the coating treatment from the external device in the previous stage by a flat flow by a sorter mechanism (not shown) or by delivery from a transfer robot (not shown) A portion 20 (FIG. 5) is provided. In the carry-out area M _OUT , the substrate G that has been subjected to the coating process is carried out to a subsequent external device by a flat flow by a sorter mechanism (not shown) or by delivery to a transfer robot (not shown). A substrate carry-out portion 22 (FIG. 5) is provided.

In the coating region M _COT , the slit nozzle 14 is provided above the stage so as to be movable up and down, and a nozzle refresh unit 24 (FIGS. 1 and 4) that refreshes the slit nozzle 14 between coating processes is provided in the substrate transport direction ( (X direction) and can be moved horizontally.

As shown in FIG. 1, the transport mechanism 12 includes a pair of guide rails 26 </ b> A and 26 </ b> B that extend in the X direction with the levitation stage 10 interposed therebetween, and a pair of sliders 28 that can reciprocate along the guide rails 26 </ b> A and 26 </ b> B. And a substrate holding member (not shown) such as a suction pad provided on the slider 28 so as to detachably hold both side ends of the substrate G on the floating stage 10, and a linear movement mechanism (not shown). The slider G is moved in the substrate transport direction (X direction) to float and transport the substrate G from the loading area M _IN through the coating area M _COT to the unloading area M _OUT on the floating stage 10. It is configured.

  The slit nozzle 14 traverses the top of the levitation stage 10 in the horizontal direction (Y direction) orthogonal to the substrate transport direction, and passes from directly below the upper surface (processing surface) of the substrate G from a slit-like discharge port. The resist solution R is discharged in a strip shape. The slit nozzle 14 is a nozzle including, for example, a ball screw mechanism 32, a guide member 34, and the like (FIG. 2) attached to a portal frame 30 installed across the floating stage 10 in parallel (in the Y direction) with the slit nozzle 14. The lifting mechanism 36 is configured to be movable (lifted / lowered) in the vertical direction (Z direction) integrally with a nozzle support member 38 that supports the nozzle 14. The slit nozzle 14 is connected via a resist supply pipe 42 to a resist supply mechanism 40 (FIG. 5) including a resist solution container and a liquid feed pump.

  As shown in FIG. 2, the resist coating apparatus includes a first air supply unit 44 for levitation and a suction / exhaust unit 46 for controlling the levitation height as external utility equipment that constitutes the substrate levitation mechanism of the levitation stage 10. And a second air supply unit 48 for cleaning the suction port.

  The first air supply unit 44 for levitation supplies positive pressure air to each of the ejection ports 16 at a desired pressure in order to float the substrate G by the pressure (lift) of the air ejected from the ejection port 16 of the levitation stage 10. Is configured to do. More specifically, the first air supply unit 44 extends to the first manifold 52 in the levitation stage 10 from the positive pressure gas supply source 50 using, for example, a compressed air source of factory power. A gas supply pipe or first air supply line 54, and an opening / closing valve 56, a regulator 58, and a filter 60 provided in the middle of the first air supply line 54 are provided.

When the on-off valve 56 is opened, positive pressure gas, that is, air is sent from the positive pressure gas supply source 50 through the air supply line 54 to the first manifold 52, and each region M _IN , M of the levitation stage 10 from the first manifold 52. _COT, air to all injection holes 16 in the M _OUT is adapted to be dispensed at a predetermined pressure.

The suction / exhaust unit 46 for controlling the flying height is used to precisely control the flying height H _G (FIG. 3 ) of the substrate G in the coating region _MCOT by the suction force that sucks air into the suction port 18. It is configured to give a moderate negative pressure. More specifically, the suction exhaust unit 46 includes, for example, a factory-use exhaust duct 62, an exhaust pipe or exhaust line 66 extending from the exhaust duct 62 to the second manifold 64 in the levitation stage 10, and an intermediate portion of the exhaust line 66. The on-off valve 68 and the fan 70 are provided.

When the on-off valve 68 is opened and the fan 70 is driven to rotate, negative pressure generated on the inlet side of the fan 70 is applied to the suction port 18 via the exhaust line 66 and the second manifold 64 to the suction port 18 in the application region _MCOT . It is transmitted. As a result, air on the floating stage 10 is sucked into the suction port 18, and the sucked air is sent to the fan 70 through the second manifold 64 and the exhaust line 66, and passes through the exhaust line 66 from the outlet side of the fan 70. Then, it is sent to the exhaust duct 62.

  The second air supply unit 48 for cleaning the suction port includes the fan 70 and the second manifold from the first node 72 on the first air supply line 54 provided between the positive pressure gas supply source 50 and the on-off valve 56. 64, a second air supply line 76 extending to the second node 74 on the exhaust line 66 provided between the second air supply line 64 and an on-off valve 78 and a regulator 80 provided in the middle of the second air supply line 76. ing.

When the fan 70 of the suction / exhaust unit 46 is stopped and the on-off valve 78 of the second air supply unit 48 is opened, the positive pressure gas, that is, the air is supplied from the positive pressure gas supply source 50 to the first supply line 54 → first. It flows into the second manifold 64 through the node 72 → the second air supply line 76 → the second node 74 → the exhaust line 66, and all the suction ports 18 in the application region M _COT of the floating stage 10 from the second manifold 64. The air is distributed and supplied at a predetermined pressure.

The resist coating apparatus, in order to match the set value H _S a H _G (Distance from the stage upper surface) flying height of the substrate G in the coating region M _COT of floating stage 10 in the feedback control, as shown in FIG. 2, The optical distance sensor 84 of the flying height measuring unit 82 (FIG. 5) is attached to the nozzle support member 38. Normally, a pair of optical distance sensors 84 are arranged on the left and right so as to measure the flying heights H _G at the left and right ends of the substrate G in the horizontal direction (Y direction) orthogonal to the substrate transport direction (FIG. 2). .

The optical distance sensor 84 optically measures a distance D _a to an object directly below the coating processing predetermined height position, that is, the floating stage 10 and a distance D _b to the substrate G. The flying height measuring unit 82 (FIG. 5) calculates a measured value of the substrate flying height H _G from the measured distances D _a and D _b and the thickness T _G (default value) of the substrate _G [H _G = D _a − (D _b + T _G )].

The resist coating apparatus further flying height monitoring unit for monitoring whether the flying height H _G of the substrate G has exceeded the allowable value even locally on a given monitor line in the vicinity immediately below the slit nozzle 14 86 (FIG. 5).

As shown in FIG. 2 , the flying height monitoring unit 86 crosses the flying stage 10 in the Y direction at a predetermined height corresponding to the flying height set value H _S on both the left and right sides of the flying stage 10. The light projecting unit 88 and the light receiving unit 90 are arranged opposite to each other on the monitoring line to be performed. When flying height H _G of the substrate G in the coating region M _COT is substantially matched to the flying height set value H _S, and where even the substrate surface on monitor line flying height monitoring unit 86 is flat, shown in FIG. 2 As described above, the light beam LB projected from the light projecting unit 88 passes through the substrate G and reaches the light receiving unit 90. However, when the flying height H _G of the substrate G exceeds the flying height set value H _S somewhere on the monitoring line, the light beam LB is reflected by the side surface or the upper surface of the substrate G and reaches the light receiving unit 90. Therefore, the flying height monitoring unit 86 can detect the situation.

  As will be described later, the monitoring function of the flying height monitoring unit 86 is used to determine whether or not the suction port 18 of the flying stage 10 is clogged near the monitoring line.

  FIG. 4 shows the configuration of the nozzle refresh unit 24. The nozzle refresh unit 24 includes a priming processing unit 96 that discharges a small amount of resist solution to the slit nozzle 14 and winds it around the priming roller 94 as a preparation for the coating process in one casing 92, and a discharge port of the slit nozzle 14. For the purpose of preventing drying, a nozzle bath 98 for keeping in an atmosphere of solvent vapor and a slit nozzle cleaning unit 100 for cleaning the periphery of the discharge port of the slit nozzle 14 are provided.

  The slit nozzle 14 that has completed one coating process is first subjected to a cleaning process by the slit nozzle cleaning unit 100, then waits in the nozzle bath 98, and is primed by the priming processing unit 96 immediately before the next coating process is started. Get processed.

  In order to place the slit nozzle 14 on each part (96, 98, 100) in the nozzle refreshing part 24, under the control of the controller 110 (FIG. 5), for example, an X-direction moving part 102 (FIG. 1) comprising a ball screw mechanism. As a result, the entire nozzle refresh unit 24, that is, the casing 92 is moved in parallel with the substrate transport direction (X direction), and the slit nozzle 14 is moved in the vertical direction (Z direction) by the nozzle lifting mechanism 36 (FIGS. 1 and 5). .

  In this embodiment, a planar suction head 102 is attached to the lower surface of the casing 92 of the nozzle refresh unit 24, and the suction head 102 is connected to the exhaust device 104 used for exhausting the priming processing unit 96 via the exhaust pipe 106. is doing. The exhaust pipe 106 is provided with an open / close valve 108. As will be described later, the suction head 102 is used when cleaning the suction port 18 of the floating stage 10.

  FIG. 5 shows the main configuration of the control system in the resist coating apparatus of this embodiment. The controller 110 is composed of a microcomputer, receives measurement values or monitor signals from the flying height measuring unit 82, the flying height monitoring unit 86, etc., and receives the transport mechanism 12, the substrate carry-in unit 20, the substrate carry-out unit 22, the nozzle refresh unit 24, The individual operations of the nozzle elevating mechanism 36, the resist supply mechanism 40, the first air supply unit 44, the suction / exhaust unit 46, the second air supply unit 48, etc. and the overall operation (sequence) are controlled. The controller 110 is also connected to a host controller and other external devices (not shown).

Here, the resist coating operation in this resist coating apparatus will be described. First, the substrate G from the front of the substrate processing apparatus (not shown) is loaded into loading area M _IN of floating stage 10 through the sorter mechanism or transport robot, where a slider 28 which has been waiting while holding the substrate G receive. On the levitation stage 10, the substrate G floats in the air by the pressure (lift) of air ejected from the ejection holes 16.

Thus, the substrate G is levitated and conveyed in the substrate conveying direction (X direction) in a horizontal posture, and when passing through the coating region _MCOT at the center of the stage, the slit nozzle 14 directs the resist solution R toward the substrate G directly below the predetermined amount. As shown in FIG. 3, a resist film coating film RM having a uniform film thickness is formed from the front end side to the rear end side of the substrate G by discharging in a strip shape with pressure or flow rate.

When the rear end of the substrate G passes under the slit nozzle 14, a resist coating film RM is formed on the entire surface of the substrate. Subsequently, the substrate G is then levitated and conveyed on the levitating stage 10 by the slider 28, and a rear stage unit (not shown) from the unloading area M _OUT set at the rear end of the levitating stage 10 via a sorter mechanism or a conveying robot. ).

  Next, the floating stage suction port cleaning function in the resist coating apparatus of this embodiment will be described with reference to FIGS.

As shown in FIG. 6, when all or most of the suction ports 18 are not clogged in the vicinity of the slit nozzle 14 in the application region _MCOT of the levitation stage 10, they are ejected from the respective outlets 16 during the coating process. After the air acts on the back surface of the substrate G, it is quickly sucked into the adjacent suction port 18.

The controller 110 closes the on-off valve 78 to stop the second air supply unit 48, operates the first air supply unit 44 and the suction exhaust unit 46 at the same time, and passes through the coating region M _COT of the substrate G. A vertical upward force due to air (compressed air) ejected from the jet outlet 16 is applied to the portion that is at the same time, and at the same time, a vertical downward force due to a negative pressure suction force is applied from the suction port 18 to oppose each other. By controlling the balance, the substrate flying height H _G for coating is maintained near the set value H _S (for example, 50 μm). In this case, the controller 110 can control the regulator 58 or the fan 70 to perform feedback control so that the flying height measurement value H _G obtained from the flying height measurement unit 82 matches the set value H _S.

However, as shown in FIG. 7, a considerable number of suction ports 18 are clogged by a relatively narrow gas passage 18a in the inner part of the application region _MCOT of the floating stage 10 in the vicinity of the slit nozzle 14 and clogged. When suction occurs, the suction port 18 that is clogged does not generate suction force even though the fan 70 of the suction exhaust unit 46 is rotating (suction / exhaust) during the coating process. In addition, in the vicinity, the balance between the floating force from the jet port 16 and the attractive force from the suction port 18 is lost, and the substrate flying height H _G is locally higher than the set value H _S.

In this case, even if the flying pressure feedback control mechanism (the controller 110, the flying height measuring unit 82, the first air supply unit 44, and the suction / exhaust unit 46) as described above is functioning normally, the substrate flying height H _G is locally increased. May miss common abnormalities (swells).

However, the flying height monitoring unit 86, when the flying height H _G of the substrate _G exceeds the flying height set value H _S regularly (while the substrate G passes) somewhere on the monitoring line, As shown in FIG. 7, since the light beam LB is blocked by the substrate G (because it does not reach the light receiving unit 90), this abnormal situation can be detected and notified to the controller 110. Even when a foreign substance is attached to the upper surface of the substrate G, the light beam LB is blocked by the foreign substance, but this is temporary, and the abnormality is canceled if the foreign substance passes, so that it can be easily distinguished. .

When the controller 110 receives from the flying height monitoring unit 86 a monitor signal for reporting an abnormality related to the flying height of the substrate, a considerable number of suctions at least near the slit nozzle 14 in the coating area M _COT of the flying stage 10. It is determined that the mouth 18 is clogged.

  When the controller 110 determines (detects) the clogging of the suction port 18 as described above, it issues an alarm through a display (not shown) or takes its history, For example, after the required lot processing is completed, execution control of the floating stage suction port cleaning operation is performed.

  In this levitation stage suction port cleaning operation, the controller 110 once turns off all the operations related to the coating process (substrate levitation operation, substrate transport operation, resist supply operation, etc.) and then opens the on-off valve 78 to perform the second operation. The air supply unit 48 is operated. At the same time, the opening / closing valve 56 is opened to operate the first air supply unit 48.

  The first air supply unit 44 and the second air supply unit 48 are connected in parallel to the positive pressure gas supply source 50 and are provided with regulators 58 and 80, respectively. The pressure of the air supplied to 16 and the pressure of the air supplied to the suction port 18 by the second air supply unit 48 can be set or adjusted independently. Normally, in the levitation stage suction port cleaning operation, the pressure of the air supplied to the suction port 18 by the second air supply unit 48 is adjusted to a sufficiently high value suitable for discharging foreign matter clogged therein, and the first supply It is preferable to adjust the pressure of the air supplied to the jet outlet 16 by the air portion 44 to a relatively low value so that dust does not enter.

By operating the second air supply unit 48, the air (compressed air) from the positive pressure gas supply source 50 is applied via the first air supply line 54 → the exhaust line 66 → the second manifold 64 as described above. It is sent to each suction port 18 in the area M _COT .

  As shown in FIG. 8, at the suction port 18 that is clogged, the foreign matter Q sandwiched in the gas passage 18a is released upward by the pressure of the air from the second manifold 64 side. The At this time, since the first air supply unit 44 is also operating, there is no possibility that the foreign matter Q discharged from the suction port 18 enters the nearby outlet 16.

On the other hand, the controller 110 raises the slit nozzle 14 to a position higher than the nozzle refresh section 24, and then slides the nozzle refresh section 24 to a position directly below the slit nozzle 14, as shown in FIG. The planar suction head 102 attached to the lower surface of the casing 92 of the nozzle refreshing unit 24 is covered on the coating area M _COT of the floating stage 10. Then, the on-off valve 108 is opened to operate the exhaust device 104 (FIG. 4).

  As a result, the foreign matter Q discharged from the suction port 18 is quickly sucked into the suction head 102 together with the air, and sent to the exhaust device 104 through the exhaust pipe 106.

As another preferred embodiment for collecting the foreign matter Q discharged from the suction port 18 by the second air supply unit 48, as shown in FIG. 9, a dummy substrate 114 having an adhesive sheet 112 attached to the lower surface is provided. A method of covering the coating area M _COT is also possible. In this case, the foreign matter Q discharged from the suction port 18 is adsorbed by the pressure-sensitive adhesive sheet 112, so that it does not roll up or reattach to the floating stage 10.

The dummy substrate 114, prior to the start of the floating stage suction port cleaning operation, is carried into the carry-region M _IN of floating stage 10 in the same manner as the target substrate G, levitation transportation until coating area M _COT by the transport mechanism 12 It is transported by. Then, after the levitation stage suction port cleaning operation is completed, it is transferred to the carry-out area M _OUT by the transfer mechanism 12 and carried out of the levitation stage 10 from the carry-out area M _OUT .

As described above, in this resist coating apparatus, while the suction port 18 provided in the coating region _MCOT of the levitation stage 10 in a mixed manner with the jet port 16 is performing the suction operation (mainly during the coating process). Foreign matter drifting around the levitation stage 10 may be sucked undesirably, and the inside of the suction port 18 may be clogged with foreign matter. However, according to this embodiment, when the coating process is paused or during the coating process, the suction / exhaust unit 44 is stopped and the second air supply unit 48 is operated, so that the eyes of the suction port 18 can be operated. The clogging can be automatically and efficiently removed without human intervention.

Further, the flying height H _G of the substrate G is constantly at the flying height set value H _S (while the substrate G is passing) somewhere on the monitoring line extending in the Y direction set near the slit nozzle 14. ) When it exceeds, the flying height monitoring unit 86 can accurately detect the abnormal situation. When the controller 110 receives a monitor signal for reporting an abnormality related to the substrate flying height from the flying height monitoring unit 86, a considerable number of suction ports 18 are clogged near the slit nozzle 14. It is possible to find the optimal time to execute the floating stage suction port cleaning operation.

  The preferred embodiments of the present invention have been described above, but the present invention is not limited to the above-described embodiments, and various modifications or changes can be made within the scope of the technical idea.

  For example, as shown in FIG. 10, a bypass system in which the second supply line 76 of the second supply unit 48 is branched from the first supply line 54 and connected to the exhaust line 66 is also possible. In this case, switching valves such as three-way valves 116 and 118 are provided at nodes of the first air supply line 54 and the second air supply line 76 and nodes of the second air supply line 76 and the exhaust line 66, respectively.

Further, a compression tank 120 is provided in the middle of the second air supply line 76 to compress the positive pressure gas from the positive pressure gas supply source 50 in the compression tank 120, and the on-off valve 78 is turned on intermittently and in pulses. As a result, as shown in FIG. 11, air having a pressure P _up that is significantly higher than the original pressure P _s is intermittently and shockfully supplied to the suction port 18 of the levitation stage 10, and is clogged in the suction port 18. The foreign matter Q can be effectively removed.

  In the configuration example of FIG. 10, when the three-way valve 116 is switched to the second air supply line 76, the positive pressure gas from the positive pressure gas supply source 50 is not supplied to the jet outlet 16 of the levitation stage 10. . As described above, when the floating stage suction port cleaning operation is executed, the first air supply unit 44 can be completely stopped. However, by omitting the three-way valve 116 and operating the first air supply unit 44 at the same time as the second air supply unit 48, air is also supplied to the outlet 16 together with the suction port 18 during the levitation stage suction port cleaning operation. It is of course possible to supply

  Although not shown, it is also possible to use an independent positive pressure gas supply source that is different from the positive pressure gas supply source 50 of the factory power, for the second air supply unit 48. Furthermore, the fan 70 of the suction / exhaust unit 46 can be configured to be reversely rotated and used as a positive pressure gas supply source for the second air supply unit 76. In that case, the exhaust line 66 can be used as the second air supply line 76 as it is.

Further, in order to increase the cleaning pressure applied to the suction port 18 of the levitation stage 10 by the second air supply section 48, as shown in FIGS. 12A and 12B, the application area M _COT of the levitation stage 10 is increased. All the suction ports 18 to be provided are divided into a plurality of groups, and the second air supply line 76 is connected through the on-off valves 122 (1), 122 (2), 122 (3), 122 (4),. The structure which connects to can be taken suitably.

  When the second air supply unit 48 is operated, that is, when the floating stage suction port cleaning operation is executed, the controller 110 performs time-sharing on-off valves 122 (1), 122 (2), 122 (3 ), 122 (4)... Are turned on, and high-pressure air is intensively supplied to the suction ports 18.

In addition, the pattern which mixes and arrange _{| positions} the jet _nozzle 16 and the suction port 18 in the application area _| region _MCOT of the levitation _| floating stage 10 is arbitrary, and is not limited to the arrangement pattern of illustration.

  In addition, it is possible to periodically perform the above-described flying stage suction port cleaning operation independently of the function of the flying height monitoring unit 86.

  In addition to the resist solution, for example, a coating solution such as an interlayer insulating material, a dielectric material, and a wiring material can be used as the processing solution in the present invention, and various chemical solutions, developing solutions, rinse solutions, and the like are also possible. The substrate to be processed in the present invention is not limited to an LCD substrate, and other flat panel display substrates, semiconductor wafers, CD substrates, photomasks, printed substrates and the like are also possible.

DESCRIPTION OF SYMBOLS 10 Floating stage 12 Conveyance mechanism 14 Slit nozzle 16 Jet outlet 18 Suction port 40 Resist supply mechanism 44 1st air supply part 46 Suction exhaust part 48 2nd air supply part 110 Controller

Claims (20)

A levitation stage having a first levitation region provided with a mixture of a large number of jet outlets and a large number of suction ports;
A first air supply unit for supplying a positive pressure gas to the jet port via the first manifold in order to float the substrate to be processed by the pressure of the gas jetted from the jet port;
A suction exhaust unit that applies a negative pressure to the suction port via a second manifold in order to control the flying height of the substrate by a suction force that sucks gas into the suction port;
A transport mechanism that holds the substrate floating in the air on the levitation stage and transports the substrate so as to pass through the first levitation region;
A processing liquid supply unit having a nozzle disposed above the first floating region, and supplying a processing liquid from the nozzle onto the substrate passing through the first floating region;
A second air supply unit that supplies a positive pressure gas to the suction port via the second manifold in order to clean the inside of the suction port.   While operating the second air supply section, a part of the first levitation region is covered from above, and a surface suction device that absorbs foreign matter mixed in the gas ejected from the suction port. The coating apparatus of Claim 1 which has a part.   While operating the second air supply unit, a planar shape that covers a part or all of the first floating region from above and adsorbs foreign matters mixed in the gas ejected from the suction port. The coating apparatus according to claim 1, further comprising an adsorption unit.   The planar suction unit can be transported by the substrate transport unit in the same manner as the substrate on the floating stage, and the first suction unit immediately before or after the operation of the second air supply unit is started. The coating apparatus according to claim 3, wherein the coating apparatus is carried over the first floating region and is removed from the first floating region after the operation of the second air supply unit is completed. A levitation stage having a first levitation region provided with a mixture of a large number of jet outlets and a large number of suction ports;
A first air supply unit for supplying a positive pressure gas to the jet port in order to float the substrate to be processed by the pressure of the gas jetted from the jet port;
A suction exhaust unit that applies a negative pressure to the suction port in order to control the flying height of the substrate by a suction force that sucks gas into the suction port;
A transport mechanism that holds the substrate floating in the air on the levitation stage and transports the substrate so as to pass through the first levitation region;
A processing liquid supply unit having a nozzle disposed above the first floating region, and supplying a processing liquid from the nozzle onto the substrate passing through the first floating region;
A second air supply unit for supplying a positive pressure gas to the suction port in order to clean the inside of the suction port;
The pressure of the gas supplied from the first air supply unit to the ejection port and the suction port are applied to the suction port so that the flying height of the substrate in the first flying region matches the flying height set value. A flying height controller that controls at least one of the vacuum pressures;
Using a light beam projected so as to be able to cross over the flying stage at a predetermined height corresponding to the flying height setting value in a horizontal direction perpendicular to the substrate transport direction, immediately below or near the nozzle. A flying height monitoring unit for optically monitoring the flying height of the substrate;
When the flying height monitoring unit detects that the flying height of the substrate constantly exceeds an allowable value somewhere on the transverse propagation path of the light beam, a part of the substrate is directly below or near the nozzle. A suction port clogging detection unit that determines that the suction port is clogged.   When cleaning the inside of the suction port, the second air supply unit is operated to eject gas from the suction port, and at the same time, the first air supply unit is also operated to gas from the jet port. The coating apparatus as described in any one of Claims 1-5 which ejects.   When cleaning the inside of the suction port, in a state where the first positive pressure gas supply unit is stopped or suspended, the second air supply unit is operated and gas is ejected from the suction port. The coating apparatus as described in any one of Claims 1-5.   The said 2nd air supply part is a coating device as described in any one of Claims 1-7 containing the positive pressure gas supply source common to a said 1st air supply part. The first air supply unit has a first air supply line extending from the positive pressure gas supply source to the jet port,
The exhaust unit includes a negative pressure generation source and an exhaust line extending from the negative pressure generation source to the suction port;
The second air supply unit has a second air supply line extending from a first node on the air supply line to a second node on the exhaust line;
The coating device according to claim 8.   The coating apparatus according to claim 9, wherein a switching valve is provided on at least one of the first and second nodes.   The coating apparatus according to claim 8, wherein the second air supply unit includes a second air supply line extending from the positive pressure gas supply source to a predetermined node on the exhaust line.   The coating device according to claim 11, wherein a switching valve is provided at the node.   The coating device according to claim 9 or 11, wherein an on-off valve is provided on the second air supply line.   A compression tank for compressing the positive pressure gas from the positive pressure gas supply source on the second air supply line, and sucking the positive pressure gas compressed by the compression tank intermittently and shockingly; The coating device according to claim 13, which is supplied to a mouth.   The coating apparatus according to claim 1, wherein the second air supply unit includes a positive pressure gas supply source that is separate from the positive pressure gas supply source used by the first air supply unit. .   When the suction port provided in the first floating region is divided into a plurality of groups and the second air supply unit is operated, the suction port is cleaned by switching in a time-sharing manner in units. The coating apparatus as described in any one of Claims 1-15.   The said levitation | floating stage has a 2nd levitation | floating area | region which provided many jet nozzles for floating the said board | substrate in the upstream of the said 1st levitation | floating area in a board | substrate conveyance direction. The coating apparatus as described in.   The coating apparatus according to claim 17, wherein a loading unit for loading the substrate is provided in the second floating region.   The said levitation | floating stage has a 3rd levitation | floating area | region which provided many jet nozzles for floating the said board | substrate in the downstream of the said 1st levitation | floating area in a board | substrate conveyance direction. The coating apparatus as described in.   The coating apparatus according to claim 19, wherein an unloading unit for unloading the substrate is provided in the third floating region.

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