JP4272230B2 - Vacuum dryer - Google Patents

Description

  The present invention relates to a reduced pressure drying apparatus that dries a coating solution applied on a substrate to be processed in a reduced pressure state.

  This type of vacuum drying apparatus, for example, prior to pre-baking a resist solution applied on a substrate to be processed (such as a glass substrate) in a photolithography process for manufacturing a flat panel display (FPD) such as a liquid crystal display (LCD). Used to dry.

A conventional vacuum drying apparatus is configured, for example, as described in Patent Document 1, such that a lower chamber of a tray or a shallow container type having an open upper surface and an upper surface of the lower chamber can be tightly adhered or fitted. And a lid-like upper chamber. A stage is disposed in the lower chamber, and after the substrate is placed horizontally on the stage, the chamber is closed (the upper chamber is brought into close contact with the lower chamber), and a vacuum drying process is performed. When loading / unloading a substrate into / from the chamber, the upper chamber is lifted by a crane or the like to open the chamber, and the stage is appropriately lifted by a cylinder or the like for loading / unloading of the substrate. Then, loading / unloading of the substrate or loading / unloading is performed by handling an external transport robot that transports the substrate around the vacuum drying apparatus. A large number of support pins protrude from the upper surface of the stage, and the substrate is placed on the support pins.
JP2000-181079

  In the conventional vacuum drying apparatus, the upper chamber is raised and lowered (opened / closed) every time the substrate is carried into and out of the chamber as described above. The inconvenience has come out. In other words, if the size of the substrate is larger than 2 m, such as an LCD substrate, the chamber will become significantly larger, and the upper chamber alone will weigh more than 2 tons, requiring a large lifting mechanism, Problems of dust generation due to vibration and safety problems for workers are becoming apparent. In addition, the transfer robot is becoming larger and larger, but it is difficult to hold a large substrate horizontally and transfer it, and the substrate just after resist coating should be transferred in a bent state like a large fan. As a result, errors such as misalignment, collision, and breakage are more likely to occur during loading / unloading of the substrate in the chamber of the vacuum drying apparatus. Further, since the substrate is subjected to a reduced-pressure drying process on the pins protruding from the upper surface of the stage in the chamber, there is also a problem that the traces of the pins are transferred to the resist film on the substrate.

  The present invention has been made in view of the above-described problems of the prior art, and allows the substrate to be processed to be loaded and unloaded efficiently and smoothly, and the transfer mark is applied to the coating film on the substrate. An object of the present invention is to provide a reduced-pressure drying apparatus that can effectively prevent the above.

  In order to achieve the above object, a reduced-pressure drying apparatus of the present invention is a reduced-pressure drying apparatus that applies a drying process to a coating solution on a substrate to be processed in a reduced pressure state, and accommodates the substrate in a substantially horizontal state. A chamber capable of being depressurized, a first exhaust mechanism for evacuating the space in the chamber in a sealed state during the drying process, and an upper surface for placing the substrate in the chamber. And a stage having a large number of gas ejection holes for ejecting a gas for levitating the substrate on the upper surface, and supplying gas for substrate levitation to the gas ejection holes through a gas line passing through the stage And a second exhaust mechanism for evacuating the gas line, and when performing the drying process, the gas line is connected to the second exhaust mechanism to connect the substrate to the second exhaust mechanism. stage It was placed on the upper surface, when performing loading and unloading of the substrate to float the substrate by connecting the gas line to the gas supply unit on the stage.

  In the above apparatus configuration, during the vacuum drying process, the space in the chamber is evacuated by the first evacuation mechanism, and the floating gas line passing through the inside of the stage is evacuated by the second evacuation mechanism to remove the substrate to be processed. Place on the top of the stage. Since there is no partial or local contact point between the substrate and the stage, there is no possibility that a transfer trace of the contact point is generated in the coating film on the substrate. In addition, since the substrate can be carried in and out of the stage with the substrate floating preferably on the stage, a transfer robot using a transfer arm is not required, and the substrate is bent like a fan and loaded / unloaded. In this case, it is not necessary to cause errors such as misalignment, collision and damage. Further, when the substrate is carried in and out, an operation of opening and closing the upper lid of the chamber is not necessary, and the problem of dust generation and the safety problem are solved.

  In a preferred aspect of the present invention, the upper surface of the stage is smaller than the substrate and larger than the product area of the substrate. In this way, the upper surface of the stage is brought into contact with the entire product area of the substrate during the vacuum drying process, and the conveying means is brought into contact with or locked to both side ends (non-product area) of the substrate protruding from the stage when the substrate is loaded / unloaded. Can do.

  As a preferred embodiment of the present invention, gas ejection holes are formed as pores having a constant density on the upper surface of the stage, or the upper surface of the stage is made of a porous material. By making the gas ejection holes small, it is possible to effectively reduce variation in thermal influence on the coating film on the substrate from the stage side.

  Further, according to a preferable aspect of the present invention, the chamber includes a carry-in port for carrying the substrate in from outside the chamber by roller conveyance, and a carry-out port for carrying the substrate out of the chamber by roller conveyance. A gate mechanism for opening and closing the carry-in port and the carry-out port is provided outside the chamber side wall. In this case, since the size of the carry-in port and the carry-out port can be such that the substrate can finally pass through the roller conveyance, the gate mechanism can be reduced in size. The carry-in port and the carry-out port may be provided separately on the side wall portion of the chamber so as to face each other, but one carry-in / out port can also be used.

  According to a preferred aspect of the present invention, a transport mechanism is provided for carrying the substrate in and out of the chamber in a flat flow. When the substrate is rectangular, the transport mechanism has a pair of transport lines that move in the substrate transport direction by making contact with both end portions of the substrate that protrude on both sides of the stage. Preferably, the transport line includes a plurality of side rollers arranged in a line at a predetermined pitch in the substrate transport direction on both sides of the stage.

  Further, in order to smoothly carry in and out the substrate, preferably, in the transport mechanism, one or two arranged side by side in the substrate transport direction between the stage and the transport inlet or between the stage and the transport outlet A configuration having a plurality of internal rollers, or a configuration having one or a plurality of external rollers arranged side by side in the substrate transport direction outside the carry-in port or outside the carry-out port may also be adopted.

  According to a preferred aspect of the present invention, a stage lifting mechanism for moving the stage up and down or moving up and down in the chamber is provided. In such a configuration, when the drying process is performed, the stage is raised to the first height position by the stage lifting mechanism so that the substrate is placed on the upper surface of the stage so as to be spaced apart from the transfer line, and the substrate is loaded. When taking out, the stage may be lowered to the second height position by the stage elevating mechanism so that the substrate is spaced upward from the stage and both end portions are placed on the transfer line.

  According to the reduced-pressure drying apparatus of the present invention, with the above-described configuration and operation, the substrate to be processed can be carried in and out efficiently and safely, and the transfer film can be effectively applied to the coating film on the substrate. Can be prevented.

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

  FIG. 1 shows a coating and developing treatment system as one configuration example to which the reduced pressure drying apparatus of the present invention can be applied. This coating and developing processing system 10 is installed in a clean room. For example, a rectangular glass substrate is used as a substrate to be processed, and a series of processes such as cleaning, resist coating, pre-baking, developing, and post-baking in a photolithography process in an LCD manufacturing process. The processing is performed. The exposure process is performed by an external exposure apparatus 12 installed adjacent to this system.

  In the coating and developing system 10, a horizontally long process station (P / S) 16 is disposed at the center, and a cassette station (C / S) 14 and an interface station (I / F) are disposed at both ends in the longitudinal direction (X direction). ) 18.

  The cassette station (C / S) 14 is a cassette loading / unloading port of the system 10, and arranges up to four cassettes C that can accommodate a plurality of substrates C in a horizontal direction (Y direction) by stacking substrates G in multiple stages. A cassette stage 20 that can be placed, and a transport mechanism 22 that takes in and out the substrate G to and from the cassette C on the stage 20 are provided. The transport mechanism 22 has a transport arm 22a that can hold the substrate G in units of one sheet, can be operated with four axes of X, Y, Z, and θ, and is adjacent to the adjacent process station (P / S) 16 side and the substrate. G can be delivered.

  In the process station (P / S) 16, the processing units are arranged in the order of the process flow or the process on a pair of parallel and opposite lines A and B extending in the horizontal system longitudinal direction (X direction).

  More specifically, the upstream process line A from the cassette station (C / S) 14 side to the interface station (I / F) 18 side includes a carry-in unit (IN PASS) 24, a cleaning process unit 26, a first The thermal processing section 28, the coating process section 30, and the second thermal processing section 32 are arranged in a line in this order from the upstream side along the first flat flow path 34.

  More specifically, the carry-in unit (IN PASS) 24 receives the unprocessed substrate G from the transfer mechanism 22 of the cassette station (C / S) 14 and inputs it into the first flat flow transfer path 34 at a predetermined tact. It is configured. The cleaning process section 26 is provided with an excimer UV irradiation unit (E-UV) 36 and a scrubber cleaning unit (SCR) 38 in order from the upstream side along the first flat flow path 34. The first thermal processing unit 28 includes an adhesion unit (AD) 40 and a cooling unit (COL) 42 in order from the upstream side. The coating process unit 30 is provided with a resist coating unit (COT) 44 and a vacuum drying unit (VD) 46 in order from the upstream side. The second thermal processing unit 32 includes a pre-bake unit (PRE-BAKE) 48 and a cooling unit (COL) 50 in order from the upstream side. A pass unit (PASS) 52 is provided at the end point of the first flat flow conveyance path 34 located adjacent to the downstream side of the second thermal processing unit 32. The substrate G that has been transported in a flat flow on the first flat flow transport path 34 is transferred from the pass unit (PASS) 52 at the end point to the interface station (I / F) 18.

  On the other hand, in the downstream process line B from the interface station (I / F) 18 side to the cassette station (C / S) 14 side, a development unit (DEV) 54, a post-bake unit (POST-BAKE) 56, a cooling unit are provided. A unit (COL) 58, an inspection unit (AP) 60 and a carry-out unit (OUT-PASS) 62 are arranged in a line in this order from the upstream side along the second flat flow path 64. Here, the post-bake unit (POST-BAKE) 56 and the cooling unit (COL) 58 constitute a third thermal processing unit 66. The carry-out unit (OUT PASS) 62 is configured to receive the processed substrates G one by one from the second flat flow transfer path 64 and pass them to the transfer mechanism 22 of the cassette station (C / S) 14. .

  An auxiliary transfer space 68 is provided between the process lines A and B, and a shuttle 70 capable of placing the substrate G horizontally in units of one sheet is both in the process line direction (X direction) by a drive mechanism (not shown). You can move in the direction.

  The interface station (I / F) 18 includes a transfer device 72 for exchanging the substrate G with the first and second flat flow transfer paths 34 and 64 and the adjacent exposure device 12. A rotary stage (R / S) 74 and a peripheral device 76 are arranged around the periphery. The rotary stage (R / S) 74 is a stage that rotates the substrate G in a horizontal plane, and is used to change the orientation of the rectangular substrate G when it is transferred to the exposure apparatus 12. The peripheral device 76 connects, for example, a titler (TITLER), a peripheral exposure device (EE), and the like to the second flat flow path 64.

  FIG. 2 shows a processing procedure of all steps for one substrate G in this coating and developing processing system. First, in the cassette station (C / S) 14, the transport mechanism 22 takes out one substrate G from any one of the cassettes C on the stage 20, and removes the taken substrate G in the process station (P / S) 16. It is carried into the carry-in unit (IN PASS) 24 on the process line A side (step S1). The substrate G is transferred or loaded onto the first flat flow path 34 from the carry-in unit (IN PASS) 24.

  The substrate G put into the first flat transport path 34 is first subjected to an ultraviolet cleaning process and a scrubbing cleaning process by the excimer UV irradiation unit (E-UV) 36 and the scrubber cleaning unit (SCR) 38 in the cleaning process unit 26. Sequentially applied (steps S2, S3). The scrubber cleaning unit (SCR) 38 removes particulate dirt from the substrate surface by performing brushing cleaning and blow cleaning on the substrate G that moves horizontally on the flat flow path 34, and then rinses. Finally, the substrate G is dried using an air knife or the like. When a series of cleaning processes in the scrubber cleaning unit (SCR) 38 is completed, the substrate G passes through the first thermal processing section 28 as it is down the first flat flow path 34.

  In the first thermal processing unit 28, the substrate G is first subjected to an adhesion process using vapor HMDS in the adhesion unit (AD) 40, and the surface to be processed is hydrophobized (step S4). After the completion of this adhesion process, the substrate G is cooled to a predetermined substrate temperature by the cooling unit (COL) 42 (step S5). Thereafter, the substrate G is carried into the coating process unit 30 along the first flat flow path 34.

  In the coating process section 30, the substrate G is first coated with a resist solution on the upper surface (surface to be processed) by a spinless method using a slit nozzle while being flown flat in a resist coating unit (COT) 44, and immediately after that, adjacent to the downstream side. A vacuum drying unit (VD) 46 receives a drying process at room temperature by a reduced pressure (step S6).

  The substrate G that has left the coating process unit 30 passes through the second thermal processing unit 32 through the first flat flow path 34. In the second thermal processing section 32, the substrate G is first pre-baked by the pre-bake unit (PRE-BAKE) 48 as a heat treatment after resist coating or a heat treatment before exposure (step S7). By this pre-baking, the solvent remaining in the resist film on the substrate G is evaporated and removed, and the adhesion of the resist film to the substrate is enhanced. Next, the substrate G is cooled to a predetermined substrate temperature by the cooling unit (COL) 50 (step S8). Thereafter, the substrate G is taken from the pass unit (PASS) 52 at the end point of the first flat flow transport path 34 to the transport device 72 of the interface station (I / F) 18.

  In the interface station (I / F) 18, the substrate G is subjected to, for example, a 90-degree direction change by the rotary stage 74 and then carried into the peripheral exposure device (EE) of the peripheral device 76, where it adheres to the peripheral portion of the substrate G. After receiving the exposure for removing the resist to be developed, the resist is sent to the adjacent exposure apparatus 12 (step S9).

  In the exposure apparatus 12, a predetermined circuit pattern is exposed to the resist on the substrate G. Then, when the substrate G that has undergone pattern exposure is returned from the exposure apparatus 12 to the interface station (I / F) 18 (step S9), it is first carried into a titler (TITLER) of the peripheral device 76, where there is a predetermined on the substrate. Predetermined information is written in the part (step S10). Thereafter, the substrate G is carried from the transfer device 72 to the starting point of the developing unit (DEV) 54 of the second flat flow transfer path 64 laid on the process line B side of the process station (P / S) 16. .

  In this way, the substrate G is transferred on the second flat flow transfer path 64 toward the downstream side of the process line B. In the first development unit (DEV) 54, the substrate G is subjected to a series of development processes of development, rinsing, and drying while being conveyed in a flat flow (step S11).

  The substrate G that has undergone a series of development processes in the development unit (DEV) 54 is sequentially passed through the third thermal processing unit 66 and the inspection unit (AP) 60 while being put on the second flat flow path 64 as it is. To do. In the third thermal processing section 66, the substrate G is first subjected to post-baking as post-development heat treatment in the post-bake unit (POST-BAKE) 56 (step S12). By this post-baking, the developing solution and the cleaning solution remaining in the resist film on the substrate G are removed by evaporation, and the adhesion of the resist pattern to the substrate is enhanced. Next, the substrate G is cooled to a predetermined substrate temperature by the cooling unit (COL) 58 (step S13). In the inspection unit (AP) 60, non-contact line width inspection, film quality / film thickness inspection, and the like are performed on the resist pattern on the substrate G (step S14).

  The carry-out unit (OUT PASS) 62 receives the substrate G that has been processed in all steps from the second flat-carrying conveyance path 64 and transfers it to the conveyance mechanism 22 of the cassette station (C / S) 14. On the cassette station (C / S) 14 side, the transfer mechanism 22 stores the processed substrate G received from the carry-out unit (OUT PASS) 62 in any one (usually the original) cassette C (step S1). ).

  In this coating and developing treatment system 10, the present invention can be applied to a vacuum drying unit (VD) 46 in the coating process unit 30. Hereinafter, the configuration and operation of the vacuum drying unit (VD) 46 in the coating process unit 30 according to a preferred embodiment of the present invention will be described in detail with reference to FIGS.

  FIG. 3 is a plan view showing the overall configuration of the coating process unit 30 in this embodiment. 4 to 8 show the configuration of the vacuum drying unit (VD) 46, FIG. 4 is a plan view thereof, FIGS. 5 and 6 are partially sectional side views, and FIGS. 7 and 8 are partially sectional rear views. It is. FIG. 9 is an enlarged cross-sectional view showing the internal structure of the stage provided in the vacuum drying unit (VD) 46.

  In FIG. 3, the resist coating unit (COT) 44 floats in the air on the floating stage 80 that constitutes a part or one section of the first flat flow path 34 (FIG. 1). A substrate transport mechanism 82 for transporting the substrate G in the longitudinal direction of the stage (X direction), a resist nozzle 84 for supplying a resist solution to the upper surface of the substrate G transported on the stage 80, and a resist nozzle 84 between the coating processes. And a nozzle refresh unit 86 for refreshing.

  A large number of gas injection holes 88 for injecting a predetermined gas (for example, air) upward are provided on the upper surface of the stage 80, and the substrate G is removed from the upper surface of the stage by the pressure of the gas injected from the gas injection holes 88. It is configured to rise to a certain height.

  The substrate transport mechanism 82 includes a pair of guide rails 90A and 90B extending in the X direction across the stage 80, a slider 92 that can reciprocate along the guide rails 90A and 90B, and both sides of the substrate G on the stage 80. And a substrate holding member (not shown) such as a suction pad provided on the slider 92 so as to detachably hold the end, and the slider 92 is moved in the transport direction (X) by a linear movement mechanism (not shown). The substrate G is floated and conveyed on the stage 80 by being moved in the direction).

  The resist nozzle 84 is an elongate nozzle extending across the stage 80 in a horizontal direction (Y direction) orthogonal to the transport direction (X direction), and the resist nozzle 84 of the substrate G that passes directly below the predetermined application position. The resist solution is discharged in a strip shape from the slit-shaped discharge port with respect to the upper surface. Further, the resist nozzle 84 is configured to be movable in the X direction integrally with the nozzle support member 94 that supports the nozzle, and is movable up and down in the Z direction, and moves between the application position and the nozzle refreshing portion 86. It can be done.

  The nozzle refresh unit 86 is held by the support member 96 at a predetermined position above the stage 80, and as a preparation for the coating process, a priming processing unit 98 for causing the resist nozzle 84 to discharge a resist solution, and a resist nozzle A nozzle bath 100 for keeping the resist discharge port 84 in a solvent vapor atmosphere for the purpose of preventing drying and a nozzle cleaning mechanism 102 for removing the resist adhering to the vicinity of the resist discharge port of the resist nozzle 84 are provided. .

  Here, main actions in the resist coating unit (COT) 44 will be described. First, the substrate G sent by, for example, roller conveyance from the first thermal processing unit 28 (FIG. 1) in the previous stage is carried into a carry-in unit set on the front end side on the stage 80, and is in a standby state there. 92 holds and receives the substrate G. On the stage 80, the substrate G receives the pressure of the gas (air) injected from the gas injection port 88 and keeps the floating state in a substantially horizontal posture.

  The slider 92 moves in the transport direction (X direction) toward the reduced-pressure drying unit (VD) 46 while holding the substrate, and when the substrate G passes under the resist nozzle 84, the resist nozzle 84 is moved to the substrate. By discharging the resist solution in a strip shape toward the upper surface of G, a liquid film of the resist solution is formed on one surface so that a carpet is laid on the substrate G from the front end to the rear end of the substrate. The substrate G thus coated with the resist solution is then levitated and conveyed on the stage 80 by the slider 92, passes over the rear end of the stage 80, and moves onto a roller conveyance path 104 described later, where the holding by the slider 92 is released. . The substrate G transferred to the roller transport path 104 is then transported on the roller transport path 104 by roller transport, as will be described later, and is carried into the subsequent vacuum drying unit (VD) 46.

  After the coated substrate G is sent to the reduced pressure drying unit (VD) 46 side as described above, the slider 92 returns to the carry-in portion on the front end side of the stage 80 in order to receive the next substrate G. The resist nozzle 84 moves from the coating position (resist liquid discharge position) to the nozzle refresh unit 86 after completing one or a plurality of coating processes, and performs refreshing or preparatory processing such as nozzle cleaning and priming. Then return to the application position.

  As shown in FIG. 3, on the extended line (downstream side) of the stage 80 of the resist coating unit (COT) 44, the roller transport that constitutes a part or one section of the first flat flow transport path 34 (FIG. 1). A road 104 is laid. The roller conveyance path 104 continues into the chamber 106 of the vacuum drying unit (VD) 46.

  Around the vacuum drying unit (VD) 46, a floating roller conveyance path 108 is provided inside the chamber 106 in addition to the above-described roller conveyance path 104 extending from the resist coating unit (COT) 44 into the chamber 106. In addition to the laying, a roller conveyance path 110 on the carry-out side is laid from the inside of the chamber 106 to the subsequent processing unit (second thermal processing unit 32).

  The carry-in side roller conveyance path 104 is configured to receive the substrate G carried out from the stage 80 of the resist coating unit (COT) 44 as an extension of the floating conveyance and send it to the chamber 106 of the vacuum drying unit (VD) 46 by roller conveyance. Has been. The floating roller conveyance path 108 draws the substrate G sent by the roller conveyance from the carry-in side roller conveyance path 104 into the chamber 106 by the floating roller conveyance at the same speed, and the vacuum drying process has been completed in the chamber 106. The substrate G is configured to be sent out of the chamber 106 (back stage) by floating roller conveyance. The carry-out side roller conveyance path 110 draws out the processed substrate G sent out by the floating roller conveyance path 108 from the floating roller conveyance path 108 to the outside of the chamber 106 by roller conveyance at the same speed, and the second thermal processing section at the subsequent stage. 32.

  As shown in FIGS. 3 to 8, the chamber 106 of the vacuum drying unit (VD) 46 is formed in a relatively flat rectangular parallelepiped and has a space in which the substrate G can be accommodated horizontally. A pair of (upstream and downstream) chamber sidewalls facing each other in the transport direction (X direction) of the chamber 106 is provided with a slit-shaped carry-in port 112 formed so as to finally pass through the substrate G in a flat flow. A carry-out port 114 is provided. Further, gate mechanisms 116 and 118 for opening and closing the carry-in port 112 and the carry-out port 114 are attached to the outer wall of the chamber 106. The upper surface portion or the upper lid 120 of the chamber 106 is removable for maintenance.

  Although not shown in the drawings, each gate mechanism 116, 118 has a lid (valve body) capable of hermetically closing the slit-shaped loading / unloading port (112, 114), and the lid body horizontally with the loading / unloading port (112, 114). A first air cylinder that moves up and down between an opposed vertical forward movement position and a lower vertical backward movement position; and a horizontal forward movement position that tightly and tightly closes the lid to the loading / unloading port (112, 114) And a second air cylinder that horizontally moves between the separated and separated horizontal return positions.

  The floating roller conveyance path 108 has a flat / rectangular stage 122 horizontally and vertically movable at the center in the chamber 106 and a substrate conveyance direction (X direction) from the carry-in port 112 to the carry-out port 114 as the front. It is composed of roller conveyance paths 124L and 124R arranged on the left and right sides of the stage 122.

  As shown in FIG. 4, a large number or an infinite number of gas ejection holes 126 are formed on the upper surface of the stage 122 with a uniform density. When the substrate G is carried in and out by the reduced pressure drying unit (VD) 46, gas (for example, air) is ejected from each gas ejection hole 126 at an appropriate pressure in order to float the substrate G on the stage 122. It has become. The upper surface of the stage 122 is a rectangle having the same shape as the substrate G, is smaller than the substrate G, and has a size larger than the product area of the substrate G. In general, in a glass substrate for LCD, a margin region having a predetermined width (for example, 20 to 30 mm width) is set at the peripheral portion of the upper surface (surface to be processed) of the LCD, and an LCD is formed in an effective region, that is, a product region inside the margin region. A device is formed. The product area is a guaranteed area where the quality of the resist film must be guaranteed. Usually, when the substrate G is centered and placed on the upper surface of the stage 122, the upper surface size of the stage 122 is selected so that each side of the substrate G protrudes by 15 mm to 20 mm from each side of the stage 122. You can.

  A hollow gas buffer chamber 128 is provided in the stage 122 as shown in FIG. The gas buffer chamber 128 communicates with a gas ejection hole 126 on the upper surface of the stage and also communicates with a pipe 130 on the lower surface of the stage. As will be described later, the gas ejection holes 126 are preferably pores or micropores in order to surely prevent variations in thermal effects on the resist film and generation of transfer marks. In the illustrated configuration example, a counterbore 127 is formed in the lower surface of the upper surface plate 122a of the stage 122, and a gas jet of a small diameter or a fine diameter (preferably φ0.3 mm or less) is formed at the center of the thin ceiling surface of the counterbore 127. Hole 126 is drilled. In the gas buffer chamber 128, pillars 132 for preventing the upper surface plate 122a from being bent are provided at appropriate positions. The pipe 130 is drawn from the outside of the chamber 106, and is configured to move up and down or expand and contract together as the stage 122 moves up and down. A hole formed in the bottom wall of the chamber 106 for passing the pipe 130 is sealed with a seal member 131.

  Outside the chamber 106, the pipe 130 communicates with the levitation gas supply unit 136 through the gas supply pipe 134 and also communicates with the vacuum exhaust apparatus 140 through the exhaust pipe 138. The gas supply pipe 134 and the exhaust pipe 138 are provided with on-off valves (electromagnetic valves) 142 and 144, respectively. The levitation gas supply unit 136 is composed of a compressor or a compressed air source having a factory force, a regulator, and the like, and sends out compressed air having a predetermined pressure. The vacuum exhaust device 140 has a vacuum pump, and has a function of evacuating the gas buffer chamber 128 in the pipe 130 and the stage 122 from the atmospheric pressure state through the exhaust pipe 138 to a reduced pressure state of a predetermined degree of vacuum. is doing.

  In order to move the stage 122 up and down, a plurality of air cylinders 146 are arranged as raising and lowering drive sources at a predetermined interval below the chamber 106, and support that penetrates the bottom wall of the chamber 106 so as to move up and down in the vertical direction. A piston rod of an air cylinder 146 is connected to the stage 122 via a shaft 148. A hole formed in the bottom wall of the chamber 106 for passing each support shaft 148 is sealed by a seal member 150 having a guide function.

  As shown in FIG. 4, the pair of roller conveyance paths 124L and 124R extending in the substrate conveyance direction (X direction) on both the left and right sides of the stage 122 has a large number of side rollers 152 arranged in a row at regular intervals in the same direction. Yes. Each side roller 152 is formed of a disk or a cylinder, and a roller support shaft 154 that extends horizontally from the center to the outside in the Y direction is rotatably supported by a bearing 156 at an intermediate portion thereof, and a magnet at the tip thereof. It is connected to a common drive shaft 160 via a bevel gear 158 of the formula. The drive shaft 160 of the right roller conveyance path 124R is connected to a rotary drive source motor 162 mounted outside the chamber 106 via a drive pulley 164, a timing belt 166, and a driven pulley 169. The drive shaft 160 of the left roller conveyance path 124L is rotated from the right drive shaft 160 via rollers 172 and 174 that respectively constitute part of the carry-in side roller conveyance path 104 and the carry-out side roller conveyance path 110 in the chamber 106. Is to be transmitted. As another configuration example, a configuration in which the drive shaft 160 of the left roller conveyance path 124L is connected to a rotation drive source different from the motor 162 is also possible.

  As shown in FIGS. 4 and 7, the side rollers 152 of the roller transport paths 124L and 124R are used when the substrate G is fed onto the stage 106 from the carry-in side roller transport path 104, or when the substrate G is on the stage. When the substrate 106 is fed from above 106 to the carry-side roller conveyance path 110, it is arranged at positions in the Z direction and Y direction such that both side ends of the substrate that protrude outside the Y direction on the stage 106 are placed on the side rollers 152. . A rubber O-ring 152a effective for preventing slipping may be mounted on the outer peripheral surface of the side roller 152 in contact with the substrate G (FIG. 7).

  An exhaust port 163 is formed at one or a plurality of locations on the bottom wall of the chamber 106. A vacuum exhaust device 140 is connected to these exhaust ports 163 via an exhaust pipe 165. The vacuum exhaust device 140 has a function of evacuating the inside of the chamber 106 from the atmospheric pressure state through the exhaust pipe 165 to a reduced pressure state with a predetermined degree of vacuum. The exhaust pipe 165 is provided with an on-off valve (electromagnetic valve) 167.

  Nitrogen gas ejection pipes 168 extending in the Y direction are provided at both ends in the chamber 106, that is, near the carry-in port 112 and the carry-out port 114 and lower than the roller transport paths 104 and 110. These nitrogen gas ejection pipes 168 are made of, for example, a porous hollow pipe formed by sintering metal powder, and are connected to a nitrogen gas supply source (not shown) via a gas supply pipe 170 (FIG. 4). ing. When returning from the reduced pressure state to the atmospheric pressure state with the chamber 106 sealed after completion of the reduced pressure drying process, these nitrogen gas ejection pipes 168 eject nitrogen gas from the entire circumferential surface.

  The rollers 172 constituting the carry-in side roller conveyance path 104 are arranged in a row at an appropriate height in the substrate conveyance direction (X direction) at a height position corresponding to the carry-in port 112. Among them, the roller 172A provided outside the chamber 106 is connected to a dedicated drive motor via an appropriate transmission mechanism, and the roller 172B in the chamber 106 is connected to the roller conveyance paths 124L and 124R as described above. The side rollers 152 and the common drive shaft 160 are connected to a common drive motor 162.

  The rollers 174 constituting the carry-out side roller conveyance path 110 are also arranged in a row at an appropriate height in the substrate conveyance direction (X direction) at a height position corresponding to the carry-out port 114. Among them, a roller 174A provided outside the chamber 106 is connected to a dedicated drive motor via an appropriate transmission mechanism, and the roller 174B in the chamber 106 is connected to the roller conveyance paths 124L and 124R as described above. The side rollers 152 and the common drive shaft 160 are connected to a common drive motor 162.

  Next, the operation of the vacuum drying unit (VD) 46 in this embodiment will be described.

  As described above, the substrate G on which the resist solution is applied by the resist application unit (COT) 44 adjacent to the upstream side moves from the floating conveyance path on the stage 80 to the carry-in side roller conveyance path 104 in a flat flow. After that, as shown in FIG. 5, the substrate G moves on the carry-in side roller conveyance path 104 by roller conveyance, and eventually enters the chamber 106 of the vacuum drying unit (VD) 46 from its carry-in port 112. At this time, the gate mechanism 116 keeps the carry-in entrance 112 open.

  The floating roller conveyance path 108 in the chamber 106 also performs a floating roller conveyance operation at the same conveyance speed as the roller conveyance operation of the carry-in side roller conveyance path 104. For this purpose, the on-off valve 144 is turned off and the on-off valve 142 is turned on, and compressed air is sent from the gas levitation gas supply unit 136 to the gas buffer chamber 128 in the stage 122 through the gas supply pipe 134 and the pipe 130. Air is ejected from the gas ejection hole 126 on the upper surface of the stage at a predetermined pressure. Further, the motor 162 is turned on to rotate all the side rollers 152 in the left and right roller conveyance paths 124L and 124R at a constant rotational speed. As a result, as shown in FIGS. 5 and 7, the substrate G that has entered from the carry-in port 112 floats on the stage 122 due to the pressure of the air received from the gas ejection holes 126, and both sides of the substrate that protrude from the stage 122 to the left and right sides. End portions ride on the side rollers 152 of the left and right roller conveyance paths 124L and 124R, respectively, and are conveyed in a flat flow in the substrate conveyance direction (X direction) by the rotation of the side rollers 152.

  As described above, when the substrate G to be subjected to the reduced pressure drying process from the preceding or upstream adjacent resist coating unit (COT) 44 is loaded into the chamber 106, simultaneously (or immediately before), the substrate G is shown in FIG. As described above, the preceding substrate G just subjected to the vacuum drying treatment in the chamber 106 is moved from the carry-out outlet 114 to the outside of the chamber 106 by the continuous constant-velocity conveyance on the floating roller conveyance path 108 and the carry-out side roller conveyance path 110. To the second thermal processing section 32 (FIG. 1) adjacent to the latter stage or downstream side. Since the substrate G receives a floating air flow from the upper surface of the stage 122 (thin and dense gas ejection holes 126) at a substantially uniform pressure during loading and unloading, the resist film on the substrate G is subjected to thermal reception from the stage 122 side. The variation in influence is small and can be substantially ignored.

  As described above, the substrate G on which the resist solution has been applied by the resist coating unit (COT) 44 is continuously dried and conveyed on the carry-in side roller conveyance path 110 and the floating roller conveyance path 108 to reduce the pressure in the drying unit. (VD) It is carried into the chamber 106 of 46. Immediately after this, the gate mechanisms 116 and 118 are operated to close the carry-in port 112 and the carry-out port 114 that have been opened so far, and the chamber 106 is sealed.

  Next, the on-off valve 142 of the levitation gas supply pipe 134 is turned off to stop the ejection of air from the upper surface (gas ejection hole 126) of the stage 122, and the elevating cylinder 146 is moved forward to move the rear surface or lower surface of the substrate G. Is moved upward from the side rollers 152 of the roller transport paths 124L and 124R, and the stage 122 is moved to a height position where the distance distance (gap) D between the upper surface of the substrate G and the ceiling surface of the chamber 108 becomes a predetermined value. Increase stroke only. The gap D is a factor or parameter that affects the flow rate of the gas flowing over the substrate G and thus the drying speed of the resist film.

  In conjunction with the upward movement of the stage 122 as described above, the on-off valves 144 and 167 of the exhaust pipes 138 and 164 are turned on to connect the floating gas lines (130 and 128) and the space in the chamber 108 to the vacuum exhaust device 140. To do. The timing for turning on the on-off valves 144 and 167 may be simultaneous, but it is usually preferable to turn on the on-off valve 144 on the floating gas line (130, 128) side earlier. Thus, the substrate G is placed in the forward (upward) height position with the back surface of the substrate 122 in direct contact with the upper surface of the stage 122, and not only in the space in the chamber 106 but also in the floating gas lines (130, 128). It is evacuated.

  By placing the substrate G in the reduced-pressure atmosphere in the chamber 106 as described above, the solvent (thinner) efficiently evaporates from the resist liquid film on the substrate G at room temperature to form a moderately dried resist film. Become. During this reduced-pressure drying process, the flat upper surface of the stage 122 is in contact with the entire product area of the substrate G, so that the temperature distribution in the substrate product area becomes substantially uniform, and transfer marks are generated in the product area of the substrate G. There is no risk. The gas ejection holes 126 provided on the upper surface of the stage 122 are fine holes or fine holes, and are distributed over the entire surface with a uniform density, which affects the temperature distribution in the substrate product region. There is no.

  The above-described decompression drying process ends when a certain time elapses or when the pressure in the chamber 106 reaches a set value, stops the evacuation operation of the vacuum evacuation device 140, and the open / close valves 144, 167 of the exhaust pipes 138, 165. Turn off. Instead, nitrogen gas is flowed into the chamber 106 through the nitrogen gas ejection pipe 168. Then, after the indoor pressure rises to atmospheric pressure, the gate mechanisms 116 and 118 are operated (returned) to open the carry-in port 112 and the carry-out port 114. Before and after this, the on-off valve 144 of the levitation gas supply pipe 134 is turned on, and compressed air is supplied from the gas levitation gas supply section 136 to the gas buffer chamber 128 in the stage 122 via the gas supply pipe 134 and the pipe 130. Then, air is ejected from the gas ejection hole 126 on the upper surface of the stage at a predetermined pressure. On the other hand, the lifting cylinder 146 is moved backward to lower the stage 122 by a predetermined stroke to a height position at which the back surface or bottom surface of the substrate G that floats on the stage 122 rides on the side rollers 152 of the roller transport paths 124L and 124R.

  Immediately after this, a flat-flow conveying operation at the same speed is started on the floating roller conveyance path 108 and the unloading side roller conveyance path 110, and the substrate G just subjected to the decompression process is transferred from the carry-out port 114 to the floating roller conveyance and the roller. It is carried out by conveyance and sent as it is to the second thermal processing section 32 (FIG. 1) at the subsequent stage as it is. Simultaneously with the carry-out operation of the processed substrate G, as shown in FIG. 5, the subsequent substrates G from the resist coating unit (COT) 44 are continuously transferred on the carry-in side roller conveyance path 104 and the floating roller conveyance path 108. It may be carried into the chamber 106 from the carry-in port 112 by smooth flow conveyance.

  As described above, the reduced-pressure drying unit (VD) 46 carries the substrate G to be subjected to the reduced-pressure drying process into the chamber 106 by roller conveyance and floating roller conveyance, and the reduced-pressure drying process is completed in the chamber 106. Since the substrate G is carried out of the chamber 106 by floating roller conveyance and roller conveyance, a conveyance robot using a conveyance arm is not necessary for loading / unloading the substrate G into / from the chamber 106, and the substrate is like a fan. It is not necessary to cause errors such as misalignment, collision and breakage during loading / unloading. In addition, since the substrate G is loaded and unloaded through the slit-shaped carry-in port 112 and the carry-out port 114 provided on the side wall of the chamber 106, the upper lid 120 of the chamber 106 is opened and closed (raised and lowered) by 1 to 2 tons or more. No operation is required, there is no problem of dust generation due to large vibrations, and safety for workers is ensured. Furthermore, since the upper surface of the stage 122 is in contact with the entire product region of the substrate G during the vacuum drying process, there is no possibility that a transfer mark of the contact member is generated in the product region of the substrate G.

  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 can be made within the scope of the technical idea.

  For example, in the floating roller conveyance path 108, the roller conveyance paths 124L and 124R provided on the left and right sides of the stage 122 can be replaced with belt conveyance paths extending in the substrate conveyance direction (X direction). Alternatively, at the time of loading / unloading the substrate G, it is coupled to the both end portions of the substrate G with suction pads to transport the substrate G in the substrate transport direction (X direction), and the suction pad is separated from the substrate G during the vacuum drying process. A simple transport mechanism is also possible. Further, it is possible to use a transfer arm of an external transfer robot as a transfer means of the floating roller transfer path 108. In this case, it is necessary to enlarge the loading / unloading ports 112 and 114 so that the transfer arm can pass along with the substrate G.

  Further, the upper surface of the stage 122 can be made of a porous material having a large number of pores instead of the perforated plate in the above embodiment. In the above embodiment, the evacuation of the space in the chamber 106 and the evacuation of the levitation gas lines (130, 128) are performed by the common (same) evacuation device 140, but may be performed by a separate and independent evacuation device. Good.

  The chamber 106 of the reduced-pressure drying unit (VD) 46 in the above-described embodiment is configured such that the substrate G passes through the chamber 106 by providing the carry-in port 112 and the carry-out port 114 on a pair of chamber side walls facing each other in the carrying direction. It was. However, it is also possible to use a structure in which a single loading / unloading port provided on one side wall of the chamber 106 serves as both a loading / unloading port. In this case, the loading-side roller conveyance path 104 and the unloading-side roller conveyance path 110 can be shared. It is peeled off.

  The substrate to be processed in the present invention is not limited to a glass substrate for LCD, and other flat panel display substrates, semiconductor wafers, CD substrates, photomasks, printed substrates and the like are also possible. The coating liquid to be dried under reduced pressure is not limited to a resist liquid, and for example, a processing liquid such as an interlayer insulating material, a dielectric material, or a wiring material is also possible.

It is a top view which shows the structure of the application | coating development processing system which can apply this invention. It is a flowchart which shows the process sequence in the said application | coating development processing system. It is a top view which shows the whole structure of the application | coating process part in embodiment. It is a top view which shows the structure of the reduced pressure drying unit in embodiment. It is a partial cross section side view which shows the state of each part at the time of carrying in / out of the reduced pressure drying unit in embodiment. It is a partial cross section side view which shows the state of each part in the vacuum drying process of the vacuum drying unit in embodiment. It is a partial cross section rear view which shows the state of each part at the time of carrying in / out of the reduced pressure drying unit in embodiment. It is a partial cross section rear view which shows the state of each part in the vacuum drying process of the vacuum drying unit in embodiment. It is an expanded sectional view showing the structure inside the stage in an embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Application | coating development processing system 30 Application | coating process part 46 Pressure reduction drying unit (VD)
104 Carrying-in roller transport path 106 Chamber 108 Floating roller transporting path 110 Carry-out roller transporting path 112 Carry-in port 114 Carry-out port 116, 118 Gate mechanism 122 Stage 124L, 124R Roller transporting path 126 Gas ejection hole
128 Gas buffer chamber 130 Piping 134 Gas supply pipe 136 Levitation gas supply section 138,165 Exhaust pipe 140 Vacuum exhaust device 142,144,167 Open / close valve 146 Air cylinder 152 Side roller 162 Motor 172 (172A, 172B) Carrying on the inlet side Roller roller 174 (174A, 174B) Roller on the unloading side roller conveyance path

Claims (13)

A vacuum drying apparatus that performs a drying process in a reduced pressure state on a coating liquid on a substrate to be processed,
A depressurizable chamber having a space for accommodating the substrate in a substantially horizontal state;
A first exhaust mechanism for evacuating the space in the chamber in a sealed state during the drying process;
A stage having an upper surface for mounting the substrate in the chamber, and a plurality of gas ejection holes for ejecting a gas for levitating the substrate on the upper surface;
A gas supply unit for supplying a gas for floating the substrate to the gas ejection hole via a gas line passing through the stage;
A second exhaust mechanism for evacuating the gas line, and when performing the drying process, the gas line is connected to the second exhaust mechanism and the substrate is placed on the upper surface of the stage. And when carrying in and out of the said board | substrate, the reduced pressure drying apparatus which connects the said gas line to the said gas supply part, and floats the said board | substrate on the said stage.   The reduced-pressure drying apparatus according to claim 1, wherein an upper surface of the stage is smaller than the substrate and larger than a product area of the substrate.   The reduced-pressure drying apparatus according to claim 1 or 2, wherein the gas ejection holes are formed as pores having a constant density on an upper surface of the stage.   The reduced-pressure drying apparatus according to claim 1 or 2, wherein an upper surface of the stage is made of a porous material. A carry-in port for carrying in the substrate from outside the chamber and a carry-out port for carrying out the substrate out of the chamber are provided in the side wall of the chamber;
The reduced-pressure drying apparatus according to any one of claims 1 to 4, wherein a gate mechanism for opening and closing the carry-in port and the carry-out port is provided outside the chamber side wall.   The vacuum drying apparatus according to claim 5, wherein the carry-in port and the carry-out port are separately provided on the side wall portion of the chamber so as to face each other.   The reduced-pressure drying apparatus according to any one of claims 1 to 6, further comprising a transport mechanism for carrying the substrate in a flat flow and transporting the substrate into and out of the chamber. The substrate is rectangular;
The vacuum drying apparatus according to claim 7, wherein the transport mechanism has a pair of transport lines that move to move the substrate in the substrate transport direction by contacting both side ends of the substrate that protrude from both sides of the stage.   The reduced-pressure drying apparatus according to claim 8, wherein the transfer line includes a plurality of side rollers arranged in a line at a predetermined pitch in the substrate transfer direction on both sides of the stage.   The transport mechanism includes one or a plurality of internal rollers arranged side by side in the substrate transport direction between the stage and the carry-in port or between the stage and the carry-out port. The vacuum drying apparatus as described in any one of these.   The decompression according to any one of claims 7 to 10, wherein the transport mechanism includes one or a plurality of external rollers arranged side by side in the substrate transport direction outside the carry-in port or the carry-out port. Drying equipment.   The reduced-pressure drying apparatus according to any one of claims 1 to 11, further comprising a stage lifting mechanism for moving the stage up and down or moving up and down in the chamber.   When performing the drying process, the stage is raised to the first height position by the stage lifting mechanism so that the substrate is placed on the upper surface of the stage so as to be spaced apart from the transfer line, and the substrate The stage is lowered to a second height position by the stage elevating mechanism so that when the substrate is carried in and out, the substrate is separated upward from the stage and both side ends of the substrate are placed on the transfer line. The reduced-pressure drying apparatus described in 1.

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