JP2007088201A - Method and device for processing substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To keep the floating height of a substrate whereto processing liquid is supplied in a floating carrying method in the proximity of a set value highly accurately. <P>SOLUTION: In a compression air supply mechanism, even if an air pressure of a factory power source 140 which is a primary side pressure of a proportional control valve 146 varies largely, pressure feed back control works by the proportional control valve 146, a pressure sensor 148 and a valve controller 150, and a secondary side pressure of the proportional control valve 146 can be thereby usually made coincide with a set pressure stably. In a vacuum supply mechanism, even if the vacuum pressure of the factory power source 154 which is a primary side pressure of a conductance valve 160 varies largely, pressure feed back control works by the conductance valve 160, the pressure sensor 162, and the valve controller 164; and the secondary side pressure of the conductance valve 160 can be thereby usually made coincide with a set pressure stably. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a technique for supplying a processing liquid onto a substrate to be processed, and more particularly to a substrate processing technique for applying a processing liquid on a substrate by a spinless method.

  Recently, in a photolithography process in a flat panel display (FPD) manufacturing process, as a resist coating method that is advantageous for increasing the size of a substrate to be processed (for example, a glass substrate), a resist solution is applied to a substrate from a long resist nozzle. 2. Description of the Related Art A spinless method is widely used in which a resist solution is applied on a substrate with a desired film thickness without requiring a rotational movement by moving or scanning a resist nozzle while discharging it in a strip shape.

A conventional resist coating apparatus using a spinless method, for example, as described in Patent Document 1, is several hundred μm between a substrate that is fixedly mounted horizontally on a stage and a discharge port of a resist nozzle provided above the stage. The following minute gap is set, and the resist solution is ejected onto the substrate while moving the resist nozzle in the scanning direction (generally in the horizontal direction perpendicular to the longitudinal direction of the nozzle). This type of resist nozzle is configured such that a nozzle body is formed in a horizontally long or long shape, and a resist solution is discharged in a strip shape from a discharge port having a very small diameter (for example, about 100 μm). When the coating process by scanning with such a long resist nozzle is completed, the substrate is taken out of the stage by the transfer robot or the transfer arm and carried out of the apparatus. Immediately after that, a subsequent new substrate is carried into the apparatus by the transfer robot and placed on the stage. Then, the same coating process as described above is repeated on the new substrate by scanning the resist nozzle.
JP-A-10-156255

In the spinless type resist coating apparatus as described above, unless a processed substrate is unloaded or unloaded from the stage to completely empty the upper surface of the stage, a subsequent new substrate is loaded or placed on the stage. I can't. For this reason, the time required for scanning the resist nozzle (T _c ), the time required for loading or unloading an unprocessed substrate onto the stage (T _in ), and the unloading of the processed substrate from the stage There is a problem that the required time (T _c + T _in + T _out ) of one cycle of the coating process that is added to the required time (T _out ) of the unloading operation becomes the tact time as it is, and it is difficult to shorten the tact time.

  The present invention has been made in view of the above-described problems of the prior art, and a substrate processing apparatus and a substrate processing for shortening the tact time of a processing operation for supplying or applying a processing liquid onto a substrate to be processed by a spinless method. It aims to provide a method.

  Another object of the present invention is to form a coating film of the processing liquid on the substrate with a uniform film thickness while keeping the flying height of the substrate to which the processing liquid is supplied in the levitation transport system stably at a set value. An object of the present invention is to provide a substrate processing apparatus and a substrate processing method which can be performed.

  In order to achieve the above object, the first substrate processing apparatus of the present invention includes a first floating region provided with a mixture of a large number of ejection ports for ejecting gas and a large number of suction ports for sucking gas. A stage having a substrate to be processed, a substrate transport unit that passes the first floating region in a predetermined transport direction in a state where the substrate to be processed is floated on the stage, and a nozzle that is disposed above the first floating region. And a processing liquid supply unit for discharging the processing liquid from the nozzle to supply the processing liquid onto the substrate, and a pressure setting corresponding to a set flying height of the substrate on the stage in the first floating region A levitation control unit that controls at least one of the pressure of the gas supplied to the jet port and the pressure of the vacuum supplied to the suction port so as to match or approximate the value.

  Further, the first substrate processing method of the present invention includes a carry-in area larger than the substrate to be processed, a coating area smaller than the substrate, and a size larger than the substrate along the transport direction on the stage. Are set in a row in this order, and the substrate is floated by the pressure of gas ejected from a number of jets provided on the upper surface of the stage, and at least in the coating region, the jets are formed on the upper surface of the stage. And controlling the balance between the vertical upward pressure applied from the jet port and the vertical downward pressure applied from the suction port to the substrate passing through the application region by providing a plurality of suction ports mixed with Apply a substantially uniform levitating force to the substrate and match or approximate the pressure set value corresponding to the set levitating amount of the substrate on the stage in the first levitating region. A nozzle disposed above in the coating region while controlling at least one of the pressure of the gas supplied to the jet port and the pressure of the vacuum supplied to the suction port and transporting the substrate from the carry-in region to the carry-out region Then, the processing liquid is discharged to apply the processing liquid onto the substrate.

  In the above configuration, the coating film of the processing liquid is formed on the substrate by receiving the supply of the processing liquid discharged from the nozzle while the substrate passes through the first floating area (coating area) of the stage. The During this coating process, even if pressure fluctuation occurs on the compressed gas supply side that supplies positive pressure gas to the stage outlet, or pressure fluctuation occurs on the vacuum source side that supplies vacuum to the suction port of the stage. Even if it occurs, pressure feedback control is applied by the flying control unit, and the flying height of the substrate in the application region of the stage is stably held near the set flying height. As a result, the gap between the nozzle and the substrate is maintained at a set value, and the levelness and floating rigidity of the substrate are maintained in a stable state, and a coating film having a constant film thickness without application unevenness is formed on the substrate. The

  According to a preferred aspect of the present invention, the levitation control unit includes a proportional control valve provided in the middle of the gas supply path connecting the positive pressure gas supply source and the jet outlet, and the secondary side of the proportional control valve. A first pressure measuring unit that measures pressure, and a second control unit that controls the opening of the proportional control valve so that the secondary pressure measurement value obtained from the first pressure measuring unit matches the first pressure set value. 1 valve control unit. In this case, the first valve control unit compares the secondary pressure measurement value from the first pressure measurement unit with the first pressure set value, and opens the proportional control valve so that the comparison error is zero. Variable control of degree. By adjusting the secondary pressure of the proportional control valve to the first pressure set value, the vertically upward pressure applied to the substrate from the jet outlet is adjusted to a predetermined value, and consequently the floating amount of the substrate is controlled as set. Can do. Preferably, the levitation control unit further includes a first pressure setting unit that gives a first pressure setting value in accordance with the thickness of the substrate, so that even if the thickness size of the substrate changes, for example, on a lot basis, The flying height can be stably adjusted to the set flying height at any time. As a preferred embodiment, a substrate thickness measuring unit that optically measures the thickness of the substrate on the stage is provided.

  According to a preferred aspect of the present invention, the levitation control unit includes a conductance valve provided in the middle of the exhaust path connecting the negative pressure source and the suction port, and a second pressure measuring the secondary side pressure of the conductance valve. A pressure measurement unit, and a second valve control unit that controls the opening of the conductance valve so that a secondary pressure measurement value obtained from the second pressure measurement unit matches a second pressure set value. Have. In this case, the second valve control unit compares the secondary pressure measurement value from the second pressure measurement unit with the second pressure setting value, and opens the conductance valve so that the comparison error is zero. Is variably controlled. By making the secondary pressure of the conductance valve coincide with the second pressure setting value, the vertical downward pressure applied to the substrate from the suction port can be adjusted to a predetermined value, and the flying height of the substrate can be controlled as set. it can. Preferably, the levitation control unit further includes a second pressure setting unit that gives a second pressure setting value in accordance with the thickness of the substrate, so that even if the thickness size of the substrate changes, for example, on a lot basis, The flying height can be stably adjusted to the set flying height at any time. Also in this case, as a preferred embodiment, a substrate thickness measuring unit that optically measures the thickness of the substrate on the stage is provided.

  Moreover, as another preferable aspect of the levitation control unit, a blower fan connected to the suction port via the exhaust path, a second pressure measurement unit that measures the pressure in the exhaust path, and the second pressure measurement A configuration having a blower control unit that controls the rotation amount of the blower fan so that the pressure measurement value obtained from the unit matches the second pressure set value is also possible.

  The second substrate processing apparatus of the present invention includes a stage having a first floating region provided with a mixture of a large number of ejection ports for ejecting gas and a large number of suction ports for sucking gas, and the substrate to be processed. A substrate transport unit that allows the first floating region to pass in a predetermined transport direction in a state of being floated on a stage; and a nozzle that is disposed above the first floating region; From a processing liquid supply unit that discharges the processing liquid from the nozzle to supply, a flying height measurement unit that measures the flying height of the substrate on the stage in the first floating region, and a flying height measurement unit And a levitation control unit that controls at least one of the pressure of the gas supplied to the ejection port and the pressure of the vacuum supplied to the suction port so that the obtained flying height measurement value matches the set levitation amount.

  Further, the second substrate processing method of the present invention includes a carry-in area larger than the substrate to be processed, a coating area smaller than the substrate, and a size larger than the substrate along the transport direction on the stage. Are set in a row in this order, and the substrate is floated by the pressure of gas ejected from a number of jets provided on the upper surface of the stage, and at least in the coating region, the jets are formed on the upper surface of the stage. And controlling the balance between the vertical upward pressure applied from the jet port and the vertical downward pressure applied from the suction port to the substrate passing through the application region by providing a plurality of suction ports mixed with A substantially uniform flying force is applied to the substrate, and the flying height of the substrate on the stage in the coating area is measured, and the measured value of the substrate flying height matches or approximates the set flying height. And controlling at least one of the pressure of the gas supplied to the jet port and the pressure of the vacuum supplied to the suction port so that the substrate is transported from the carry-in region to the carry-out region in the coating region. The processing liquid is discharged from a nozzle disposed above to apply the processing liquid on the substrate.

  Also in the above configuration, a coating film of the processing liquid is formed on the substrate by receiving the supply of the processing liquid discharged from the nozzle while the substrate passes through the first floating area (coating area) of the stage. The During this coating process, even if pressure fluctuation occurs on the compressed gas supply side that supplies positive pressure gas to the stage outlet, or pressure fluctuation occurs on the vacuum source side that supplies vacuum to the suction port of the stage. Even if it occurs, feedback control that feeds back the measurement value of the substrate flying height is applied in the flying control unit, and the substrate flying height in the coating region of the stage is held with high accuracy near the set flying height. As a result, the gap between the nozzle and the substrate is maintained at a set value with high accuracy, and the levelness and floating rigidity of the substrate are kept stable with high accuracy, and a uniform film thickness without uneven coating on the substrate is maintained. A coating film is formed.

  According to a preferred aspect of the present invention, the levitation control unit includes a proportional control valve provided in the middle of the gas supply path connecting the positive pressure gas supply source and the jet outlet, and the secondary side of the proportional control valve. A first pressure measuring unit that measures pressure, and a second control unit that controls the opening of the proportional control valve so that the secondary pressure measurement value obtained from the first pressure measuring unit matches the first pressure set value. 1 valve control unit, and a first pressure setting unit that variably controls the first pressure set value so that the measured flying height matches the set flying height. In this case, the proportional control valve, the first pressure measurement unit, and the first valve control unit form a pressure feedback loop that matches the secondary pressure of the proportional control valve with the first pressure set value, and The pressure setting value of 1 is variably adjusted by the first pressure setting unit so that the flying height measurement value matches the set flying height. Thus, the flying height of the substrate can be directly controlled as set.

  According to a preferred aspect, the levitation control unit includes a conductance valve provided in the middle of the exhaust path connecting the negative pressure source and the suction port, and a second pressure measuring the secondary pressure of the conductance valve. A second valve control unit that controls the opening of the conductance valve so that a secondary pressure measurement value obtained from the second pressure measurement unit matches a second pressure set value; And a second pressure setting unit that variably controls the second pressure set value so that the measured flying height matches the set flying height. In this case, the conductance valve, the second pressure measuring unit, and the second valve control unit form a pressure feedback loop for matching the secondary pressure of the conductance valve to the second pressure set value, and the second The pressure set value is variably adjusted by the second pressure setting unit so that the measured flying height matches the set flying height. Thus, the flying height of the substrate can be directly controlled as set.

  Alternatively, as another preferred aspect, the levitation control unit includes a blower fan connected to the suction port via the exhaust path, a second pressure measurement unit that measures the pressure in the exhaust path, and the second A blower control unit that controls the rotation amount of the blower fan so that the pressure measurement value obtained from the pressure measurement unit matches the second pressure setting value, and the second value so that the flying height measurement value matches the set flying height. A configuration having a second pressure setting unit that variably controls the pressure setting value is also possible.

  As a preferred embodiment, the flying height measuring unit includes an optical distance sensor for optically measuring the distance between the substrate and the upper surface of the stage. In addition, a nozzle raising / lowering unit for moving the nozzle up and down in the vertical direction is provided.

  According to a preferred aspect, there is provided a second levitation area for floating the substrate upstream of the first levitation area in the stage conveyance direction, and the substrate is carried into the second levitation area. Is provided. Further, a third floating region for floating the substrate is provided on the downstream side of the first floating region in the stage transport direction, and a carry-out unit for carrying the substrate out is provided in the third floating region.

  Further, according to a preferred aspect, the substrate transporting section is arranged on one or both sides of the stage so as to extend in parallel with the direction in which the substrate moves, and a slider movable along the guide rail, The conveyance driving unit drives the slider so as to move along the guide rail, and the holding unit extends from the slider toward the center of the stage and detachably holds the side edge of the substrate.

  According to the substrate processing apparatus and the substrate processing method of the present invention, due to the configuration and operation as described above, not only can the tact time of the processing operation of supplying or coating the processing liquid on the substrate to be processed by the spinless method be reduced, but also floating In the transport method, the flying height of the substrate to which the processing liquid is supplied can be stably maintained near the set value, and the coating film of the processing liquid can be formed on the substrate with a uniform film thickness without unevenness.

  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 a configuration example to which the substrate processing apparatus and the substrate processing method of the present invention can be applied. This coating / development processing system is installed in a clean room and uses, for example, an LCD substrate as a substrate to be processed, and performs cleaning, resist coating, pre-baking, development, and post-baking in the photolithography process in the LCD manufacturing process. is there. The exposure process is performed by an external exposure apparatus (not shown) installed adjacent to this system.

  This coating and developing system is roughly divided into a cassette station (C / S) 10, a process station (P / S) 12, and an interface unit (I / F) 14.

  A cassette station (C / S) 10 installed at one end of the system includes a cassette stage 16 on which a predetermined number, for example, four cassettes C for storing a plurality of substrates G can be placed, and a side on the cassette stage 16. And a transport path 17 provided in parallel with the arrangement direction of the cassette C, and a transport mechanism 20 that is movable on the transport path 17 and that allows the substrate C to be taken in and out of the cassette C on the stage 16. The transport mechanism 20 has a means for holding the substrate G, for example, a transport arm, can be operated with four axes of X, Y, Z, and θ, and is transported on the process station (P / S) 12 side described later. And the substrate G can be transferred.

  The process station (P / S) 12 includes, in order from the cassette station (C / S) 10 side, a cleaning process unit 22, a coating process unit 24, and a development process unit 26, a substrate relay unit 23, a chemical solution supply unit 25, and It is provided in a horizontal row via (spaced) the space 27.

  The cleaning process unit 22 includes two scrubber cleaning units (SCR) 28, an upper and lower ultraviolet irradiation / cooling unit (UV / COL) 30, a heating unit (HP) 32, and a cooling unit (COL) 34. Contains.

  The coating process unit 24 includes a spinless resist coating unit (CT) 40, a vacuum drying unit (VD) 42, an upper and lower two-stage adhesion / cooling unit (AD / COL) 46, and an upper and lower two-stage heating / cooling. A unit (HP / COL) 48 and a heating unit (HP) 50 are included.

  The development process unit 26 includes three development units (DEV) 52, two upper and lower two-stage heating / cooling units (HP / COL) 53, and a heating unit (HP) 55.

  Conveying paths 36, 51, and 58 are provided in the longitudinal direction in the center of each process unit 22, 24, and 26, and the conveying devices 38, 54, and 60 move along the conveying paths 36, 51, and 58, respectively. Each unit in the process unit is accessed to carry in / out or carry the substrate G. In this system, in each process part 22, 24, 26, a liquid processing unit (SCR, CT, DEV, etc.) is disposed on one side of the transport paths 36, 51, 58, and heat treatment is performed on the other side. System units (HP, COL, etc.) are arranged.

  The interface unit (I / F) 14 installed at the other end of the system is provided with an extension (substrate transfer unit) 56 and a buffer stage 57 on the side adjacent to the process station 12, and is transported to the side adjacent to the exposure apparatus. A mechanism 59 is provided. The transport mechanism 59 is movable on the transport path 19 extending in the Y direction, and is used to load and unload the substrate G with respect to the buffer stage 57, and to extend from the extension (substrate transfer unit) 56 and the adjacent exposure device. The substrate G is transferred.

  FIG. 2 shows a processing procedure in this coating and developing processing system. First, in the cassette station (C / S) 10, the transport mechanism 20 takes out one substrate G from a predetermined cassette C on the stage 12 and transports it to the cleaning process unit 22 of the process station (P / S) 12. It is passed to the device 38 (step S1).

  In the cleaning process section 22, the substrate G is first sequentially carried into an ultraviolet irradiation / cooling unit (UV / COL) 30, subjected to dry cleaning by ultraviolet irradiation in the first ultraviolet irradiation unit (UV), and then subjected to the next cooling unit ( In COL), the temperature is cooled to a predetermined temperature (step S2). This UV cleaning mainly removes organic substances on the substrate surface.

  Next, the substrate G is subjected to a scrubbing cleaning process by one of the scrubber cleaning units (SCR) 28 to remove particulate dirt from the substrate surface (step S3). After the scrubbing cleaning, the substrate G is subjected to dehydration treatment by heating in the heating unit (HP) 32 (step S4), and then cooled to a constant substrate temperature by the cooling unit (COL) 34 (step S5). Thus, the pretreatment in the cleaning process unit 22 is completed, and the substrate G is transferred to the coating process unit 24 by the transfer device 38 via the substrate transfer unit 23.

  In the coating process unit 24, the substrate G is first sequentially carried into an adhesion / cooling unit (AD / COL) 46, and undergoes a hydrophobic treatment (HMDS) in the first adhesion unit (AD) (step S6). The cooling unit (COL) cools to a constant substrate temperature (step S7).

  Thereafter, the substrate G is coated with a resist solution by a spinless method in a resist coating unit (CT) 40, and then subjected to a drying process by reduced pressure in a reduced pressure drying unit (VD) 42 (step S8).

  Next, the substrate G is sequentially carried into the heating / cooling unit (HP / COL) 48, and the first heating unit (HP) performs baking after coating (pre-baking) (step S9), and then the cooling unit ( COL) to cool to a constant substrate temperature (step S10). In addition, the heating unit (HP) 50 can also be used for baking after this application | coating.

  After the coating process, the substrate G is transported to the interface unit (I / F) 14 by the transport device 54 of the coating process unit 24 and the transport device 60 of the development process unit 26, and is passed from there to the exposure apparatus (step). S11). In the exposure apparatus, a predetermined circuit pattern is exposed on the resist on the substrate G. After the pattern exposure, the substrate G is returned from the exposure apparatus to the interface unit (I / F) 14. The transport mechanism 59 of the interface unit (I / F) 14 passes the substrate G received from the exposure apparatus to the development process unit 26 of the process station (P / S) 12 via the extension 56 (step S11).

  In the development process unit 26, the substrate G is subjected to development processing in any one of the development units (DEV) 52 (step S12), and then sequentially carried into one of the heating / cooling units (HP / COL) 53, Post baking is performed in the first heating unit (HP) (step S13), and then the substrate is cooled to a constant substrate temperature in the cooling unit (COL) (step S14). A heating unit (HP) 55 can also be used for this post-baking.

  The substrate G that has undergone a series of processing in the development process section 26 is returned to the cassette station (C / S) 10 by the transfer devices 60, 54, and 38 in the process station (P / S) 24, where the transfer mechanism 20 Is stored in one of the cassettes C (step S1).

  In this coating and developing system, the present invention can be applied to, for example, the resist coating unit (CT) 40 of the coating process unit 24. Hereinafter, an embodiment in which the present invention is applied to a resist coating unit (CT) 40 will be described with reference to FIGS.

  FIG. 3 shows the overall configuration of the resist coating unit (CT) 40 and the vacuum drying unit (VD) 42 in this embodiment.

As shown in FIG. 3, a resist coating unit (CT) 40 and a vacuum drying unit (VD) 42 are arranged in a horizontal row on the support base or support frame 70 in the X direction. A new substrate G to be subjected to the coating process is carried into the resist coating unit (CT) 40 as indicated by an arrow F _A by the transfer device 54 (FIG. 1) on the transfer path 51 side. Substrate G after completion of the coating process in the resist coating unit (CT) 40 is a transfer arm 74 which is movable in the X direction is guided by the guide rails 72 on the support table 70, a vacuum drying unit as indicated by the arrow F _B (VD) 42. Substrate G having been subjected to the drying treatment in a vacuum drying unit (VD) 42 is drawn off as shown by the arrow F _C by the transfer device 54 of the transport path 51 side (FIG. 1).

  The resist coating unit (CT) 40 includes a stage 76 that extends long in the X direction, and is a long type that is disposed above the stage 76 while the substrate G is transported in the same direction on the stage 76. A resist solution is supplied onto the substrate G from the resist nozzle 78, and a resist coating film having a constant film thickness is formed on the upper surface (surface to be processed) of the substrate by a spinless method. The configuration and operation of each part in the unit (CT) 40 will be described in detail later.

  The vacuum drying unit (VD) 42 includes a tray or shallow container type lower chamber 80 having an open upper surface, and a lid-shaped upper chamber configured to be tightly fitted or fitted to the upper surface of the lower chamber 80. (Not shown). The lower chamber 80 is substantially rectangular, and a stage 82 for placing and supporting the substrate G horizontally is disposed at the center, and exhaust ports 83 are provided at the four corners of the bottom surface. Each exhaust port 83 communicates with a vacuum pump (not shown) through an exhaust pipe (not shown). With the lower chamber 80 covered with the upper chamber, the sealed processing space in both chambers can be depressurized to a predetermined degree of vacuum by the vacuum pump.

  4 and 5 show a more detailed overall configuration in the resist coating unit (CT) 40 in one embodiment of the present invention.

  In the resist coating unit (CT) 40 of this embodiment, the stage 76 does not function as a mounting table for fixing and holding the substrate G as in the prior art, but a substrate for floating the substrate G in the air by the force of air pressure. It functions as a levee. Then, the linear movement type substrate transport portions 84 arranged on both sides of the stage 76 hold both side edges of the substrate G floating on the stage 76 in a detachable manner, and the stage longitudinal direction (X direction) The substrate G is transferred to the substrate.

Specifically, the stage 76 is divided into _five regions M ₁ , M ₂ , M ₃ , M ₄ , and M ₅ in the longitudinal direction (X direction) (FIG. 5). The leftmost area M ₁ is a carry-in area, and a new substrate G to be subjected to the coating process is carried into a predetermined position in this area M ₁ . In this carry-in area M ₁ , the substrate G is received from the transfer arm of the transfer device 54 (FIG. 1) and loaded onto the stage 76 so as to move up and down between the original position below the stage and the forward movement position above the stage. A plurality of possible lift pins 86 are provided at predetermined intervals.

The loading area M ₁ is also the area substrate transfer of a floating starts, high-pressure or positive pressure to the stage upper surface of the region to float in flying height or flying height H _a for carrying the substrate G A number of jet outlets 88 for jetting compressed air are provided at a constant density. Here, the flying height H _a of the substrate G in the carrying region M ₁ does not require a particularly high accuracy, for example if kept in the range of 100-150 .mu.m. Further, it is preferable that the size of the carry-in area M ₁ exceeds the size of the substrate G in the transport direction (X direction). Furthermore, an alignment unit (not shown) for aligning the substrate G on the stage 76 may be provided in the carry-in region M ₁ .

A region M ₃ set at the center of the stage 76 is a resist solution supply region or a coating region, and the substrate G receives supply of the resist solution R from the upper resist nozzle 78 when passing through this region M ₃ . The substrate flying height _Hb in the coating region M ₃ defines a gap S (for example, 100 μm) between the lower end (discharge port) of the nozzle 78 and the upper surface of the substrate (surface to be processed). The gap S is an important parameter that affects the film thickness of the resist coating film and the resist consumption, and must be kept constant with high accuracy. From this, on the upper surface of the stage of the application region M ₃ , for example, a jet that ejects high-pressure or positive-pressure compressed air to float the substrate G with a desired flying height H _b in an arrangement or distribution pattern as shown in FIG. An outlet 88 and a suction port 90 for sucking air with a negative pressure are mixed and provided. Then, a vertical upward force due to compressed air is applied from the jet outlet 88 to a portion passing through the coating region M ₃ of the substrate G, and at the same time, a vertical downward force due to a negative pressure suction force is applied from the suction port 90. In addition, the flying height _Hb for application is maintained in the vicinity of a set value H _S (for example, 50 μm) by controlling the balance of the opposing forces. The size of the coating region M ₃ in the transport direction (X direction) only needs to be large enough to stably form the narrow coating gap S as described above immediately below the resist nozzle 78, and is usually larger than the size of the substrate G. It may be small, for example, about 1/3 to 1/4.

As shown in FIG. 6, in the application region M ₃ , the jet ports 88 and the suction ports 90 are alternately arranged on a straight line C that forms an angle inclined with respect to the substrate transport direction (X direction). An appropriate offset α is provided for the pitch on the straight line C between the columns. According to such an arrangement pattern, not only can the mixing density of the nozzles 88 and the suction ports 90 be made uniform, the substrate levitation force on the stage can be made uniform, but also when the substrate G moves in the transport direction (X direction). It is also possible to make the ratio of the time facing the 88 and the suction port 90 uniform in each part of the substrate, whereby the coating film formed on the substrate G is traced or transferred by the ejection port 88 or the suction port 90. Can be prevented. At the entrance of the coating region M ₃ , the jet outlets 88 arranged in the same direction (on the straight line J) so that the tip of the substrate G stably receives a uniform levitation force in the direction (Y direction) perpendicular to the transport direction, and It is preferable to increase the density of the suction port 90. Also in the coating region M ₃ , it is preferable to arrange only the ejection port 88 at both side edges (on the straight line K) of the stage 76 in order to prevent the both side edges of the substrate G from dripping.

Middle area M ₂ that is set between the loading area M ₁ and the application area M ₃ are, floating in the coating area M ₃ of the flying height of the substrate G during transport from the flying height H _a of the loading area M ₁ This is a transition region for changing or transitioning to the quantity _Hb . Even in the transition region M ₂ , the jet port 88 and the suction port 90 can be mixed and arranged on the upper surface of the stage 76. In that case, the density of the suction port 90 gradually increases along the conveying direction, whereby it as the flying height of the substrate G during transport moves in H _b from progressively H _a. Alternatively, in this transition region M ₂ , a configuration in which only the ejection port 88 is provided without including the suction port 90 is also possible.

Downstream region M ₄ next to the coating area M ₃ are, the transition region for changing the flying height H _c for unloading (e.g. 100-150 .mu.m) from flying height H _b of coating the flying height of the substrate G during transport It is. Even in the transition region M ₂ , the ejection port 88 and the suction port 90 may be mixed on the upper surface of the stage 76, and in this case, the density of the suction port 90 should be gradually reduced along the transport direction. . Alternatively, a configuration in which only the ejection port 88 is provided without including the suction port 90 is also possible. In addition, as shown in FIG. 6, in the transition region M ₄ as well as the coating region M ₃ , the suction port 90 (and the spray nozzle 90) is used to prevent the transfer mark from being applied to the resist coating film formed on the substrate G. It is preferable that the outlet 88) is disposed on a straight line E that forms a certain inclined angle with respect to the substrate transport direction (X direction), and an appropriate offset β is provided in the arrangement pitch between adjacent rows.

A region M ₅ at the downstream end (right end) of the stage 76 is a carry-out region. The resist coating unit (CT) substrate G having received a coating process with 40, the transport arm 74 from a predetermined position or unloading position of the unloading area M ₅ vacuum drying unit on the downstream side next (FIG. 3) (VD) 42 ( 3). In the carry-out area M ₅ , a number of jet outlets 88 for floating the substrate G with a flying height H _c for carrying out are provided on the upper surface of the stage at a constant density, and the substrate G is unloaded from the stage 76. Thus, a plurality of lift pins 92 that can be moved up and down between the original position below the stage and the forward movement position above the stage are provided at predetermined intervals for delivery to the transfer arm 74 (FIG. 3).

  The resist nozzle 78 has a long nozzle body that can cover the substrate G on the stage 76 from one end to the other end and extends in a direction (Y direction) orthogonal to the transport direction, and is a gate shape or an inverted U shape. The nozzle support 140 is attached to the nozzle support 140 so as to be movable up and down, and is connected to a resist solution supply pipe 94 (FIG. 4) from a resist solution supply source (not shown). In FIG. 4, a vertically extending rod 136 for supporting the resist nozzle 78 is connected to the drive shaft of the nozzle lifting / lowering unit 138 (FIG. 11).

  As shown in FIGS. 4, 7, and 8, the substrate transport unit 84 includes a pair of guide rails 96 arranged in parallel on the left and right sides of the stage 76, and an axial direction (X direction) on each guide rail 96. A slider 98 movably attached to each other, a transport drive unit 100 for moving the slider 98 linearly on each guide rail 96, and right and left side edges of the substrate G extending from each slider 98 toward the center of the stage 76. And a holding portion 102 that holds the detachable holder.

  Here, the conveyance drive unit 100 is configured by a linear drive mechanism such as a linear motor. The holding unit 102 supports the suction pad 104 coupled to the lower surfaces of the left and right side edges of the substrate G by a vacuum suction force, and supports the suction pad 104 at the distal end, with the proximal end on the slider 98 side serving as a fulcrum. And a plate spring type pad support portion 106 that can be elastically deformed so that the height position of each can be changed. The suction pads 104 are arranged in a line at a constant pitch, and the pad support part 106 supports each suction pad 104 independently. As a result, the individual suction pads 104 and the pad support portions 106 can stably hold the substrate G at independent height positions (even at different height positions).

  As shown in FIGS. 7 and 8, the pad support portion 106 in this embodiment is attached to a plate-like pad elevating member 108 attached to the inner surface of the slider 98 so as to be elevable. A pad actuator (not shown) made of an air cylinder, for example, mounted on the slider 98 moves the pad lifting / lowering member 108 from the original position (retracted position) lower than the flying height position of the substrate G and the flying height of the substrate G. It is configured to move up and down between the forward movement position (coupling position) corresponding to the position.

  As shown in FIG. 9, each suction pad 104 is provided with a plurality of suction ports 112 on the upper surface of a rectangular parallelepiped pad body 110 made of, for example, synthetic rubber. These suction ports 112 are slit-like long holes, but may be round or rectangular small holes. For example, a belt-like vacuum tube 114 made of synthetic rubber is connected to the suction pad 104. The pipe lines 116 of these vacuum pipes 114 respectively communicate with a vacuum source (not shown) for pad suction.

  As shown in FIG. 4, the holding unit 102 preferably has a separation type or completely independent type in which the vacuum suction pads 104 and the pad support units 106 on one side are separated for each set. However, as shown in FIG. 10, a single plate spring provided with a notch 118 is used to form a pad support portion 120 for one row on one side, and a vacuum suction pad 104 is placed on one row on the pad support portion 120. Configuration is also possible.

As described above, a number of ejection ports 88 and compressed air supply mechanism for supplying compressed air for levitation force generated in them are formed on the upper surface of the stage 76, still more spout in the coating area M ₃ of the stage 76 88 In the carry-in area M ₁ and the carry-out area M ₅ , the substrate G is brought into a floating amount suitable for carry-in / out and high-speed conveyance. In the coating area M ₃ , the substrate G is floated with a set flying height H _S suitable for stable and accurate resist coating scanning.

However, the compressed air source of the compressed air supply mechanism and the vacuum source of the vacuum supply mechanism are usually provided as power sources shared by each part of the factory, and not only the resist coating unit (CT) 40 but also various other systems. At the same time, compressed air and vacuum are also distributed to the equipment unit. Such factory power usually fluctuates according to the operation status of the whole factory. For this reason, each device unit has a regulator for lowering and stabilizing the pressure of compressed air from the factory power source to the set value, and for increasing and stabilizing the vacuum pressure from the factory power source to the set value. A throttle valve is provided. However, when the pressure fluctuation on the factory power source side is very large, the pressure fluctuation may be transmitted to the secondary side of the regulator or the throttle valve. In that case, in the resist coating unit (CT) 40, the influence of pressure fluctuations in the substrate flying height H _b of (directly below the particular nozzle 78) stage coating area M ₃ is remarkable.

By the way, maintaining the flying height H _b of the substrate G at the set value H _S in the coating region M ₃ (particularly immediately below the nozzle 78) as described above not only keeps the coating gap S constant but also the substrate G. It is also important to maintain levelness. In other words, the flying height setting value H _S is optimal for obtaining sufficient rigidity (substrate floating rigidity) for holding the floating substrate G horizontally without causing the substrate G to rub the upper surface of the stage 76. Chosen for flying height. If the actual substrate flying height _Hb is larger than the set value H _S , the substrate flying rigidity decreases, the substrate G shakes up and down, loses its levelness, and uneven coating tends to occur. On the other hand, when the substrate flying height H _b is smaller than the set value H _S, trouble such as foreign matter such as dust on the stage 76 to the substrate G in levitation transportation adheres or hit is readily released. Accordingly, the fact that the substrate flying height _{Hb in the} coating region M ₃ (particularly immediately below the nozzle 78) cannot be stably maintained near the set value H _S due to pressure fluctuations in the factory force is the performance and reliability of the floating resist coating method. Result in a significant reduction in

In this embodiment, the flying height control mechanism as described below is used to set the flying height _Hb of the substrate G in the coating region M ₃ (especially immediately below the nozzle 78) even if there is a large fluctuation in the pressure of the factory force. and constantly stably kept at about H _S, is to be able to form a uniform resist film without coating unevenness on the substrate G.

  FIG. 11 shows the configuration of the levitation pressure control mechanism in this embodiment. The flying pressure control mechanism controls the compressed air supply mechanism and the vacuum supply mechanism at the same time.

  In the compressed air supply mechanism, the compressed air source 140 for factory power is connected to the compressed air introduction part 144 of the stage 76 via a pipe or a compressed air supply pipe 142. A proportional control valve 146 comprising a regulator is provided. Further, a pressure sensor 148 made of, for example, a gauge pressure gauge is attached to the compressed air supply pipe 142 on the secondary side of the proportional control valve 146. The valve controller 150 receives the output signal (pressure detection signal) sa of the pressure sensor 148 and opens the proportional control valve 146 so that the pressure detection signal sa matches the predetermined reference value SA given from the main control unit 152. The degree is variably controlled by a control signal. Here, the reference value SA corresponds to the set value A of the secondary pressure of the proportional control valve 146. A manifold (not shown) is provided for each region M between the compressed air introduction part 144 of the stage 76 and the jet outlet 88 (FIGS. 4 to 6) on the upper surface of the stage 76. According to such a configuration, since the pressure feedback control is performed by the proportional control valve 146, the pressure sensor 148, and the valve controller 150, even if the primary pressure of the proportional control valve 146, that is, the air pressure of the factory power source 140 varies greatly, The secondary pressure of the control valve 146 can be made consistent with the set pressure A stably at all times.

  In the vacuum supply mechanism, the factory power vacuum source 154 is connected to a vacuum introduction section 158 of the stage 76 via a pipe or a vacuum pipe 156, and a conductance valve 160 is provided in the middle of the vacuum pipe 156. Further, a pressure sensor 162 composed of, for example, a gauge pressure gauge is attached to the vacuum pipe 156 on the secondary side of the conductance valve 160. The valve controller 164 receives the output signal (pressure detection signal) sb of the pressure sensor 162 and opens the valve opening of the conductance valve 160 so that the pressure detection signal sb matches the predetermined reference value SB given from the main control unit 152. Is variably controlled by a control signal. Here, the reference value SB corresponds to the set value B of the secondary pressure of the conductance valve 160. A manifold (not shown) is provided for each region M between the vacuum introducing portion 158 of the stage 76 and the suction port 90 (FIGS. 4 to 6) on the upper surface of the stage 76. According to this configuration, pressure feedback control is performed by the conductance valve 160, the pressure sensor 162, and the valve controller 164. Therefore, even if the primary pressure of the conductance valve 160, that is, the vacuum pressure of the factory power source 154 fluctuates greatly, the conductance valve 160 The secondary side pressure can be made consistent with the set pressure B stably at all times.

As described above, in the compressed air supply mechanism, the secondary pressure of the proportional control valve 146 is stably maintained with high accuracy near the set pressure A, so that the substrate G is applied from the ejection port 88 in the application region M ₃ of the stage 76. The air pressure applied to is stably maintained at a predetermined value with high accuracy. Further, by the secondary pressure of the conductance valve 160 in the vacuum supply mechanism is stably held at a high accuracy in the vicinity of the set pressure B, vacuum pressure applied to the substrate G from the suction port 90 in the coating area M ₃ of the stage 76 Is stably maintained at a predetermined value with high accuracy. In this way, the difference between the air pressure and the vacuum pressure simultaneously applied to the substrate G is stably maintained at a predetermined value with high accuracy, so that the substrate flying height H _b in the coating region M ₃ (particularly immediately below the resist nozzle 78) is reduced. It is stably maintained near the set value H _S (50 μm).

The main control unit 152, a microcomputer, in the resist coating unit (CT) controls operation of each unit 40, coating area M ₃ valve controller 150,164 as described above for the floating pressure control within Reference values SA and SB for feedback control are given. In the memory of the main controller 152, for example, as shown in FIG. 12, the secondary side pressure (positive pressure) of the proportional control valve 146 and the desired set flying height H _S for each thickness D _{i of the} substrate G and A data table for associating the set values A _i and B _i of the secondary side pressure (negative pressure) of the conductance valve 160 is constructed. Here, the thickness of the substrate G has several different sizes such as 0.50 mm, 0.75 mm, and 0.90 mm for each product of the glass substrate, and is also an index representing the weight per unit area of the substrate G. Therefore, it is a parameter. In this data table, instead of the set values A _i and B _i , feedback reference values SA _i and SB _i corresponding thereto may be set.

The main control unit 152 also exchanges commands and data with a system controller (not shown) that performs overall control of the entire coating and developing treatment system. If data regarding the thickness of each substrate G currently flowing in the system is available, the pressure set value A _i corresponding to the thickness D _{i of the} substrate G is referred to the data table (FIG. 12). It reads the B _i, respectively pressure setting to the valve controller 164 of the valve controller 150 and the vacuum supply mechanism of the compressed air supply mechanism value a _i, a reference value SA _i corresponding to B _i, may be given the SB _i.

  The main control unit 152 also monitors the output signals (pressure detection signals) sa and sb of the pressure sensors 148 and 162, and the pressure detection signals sa and sb are converted to the reference values SA and s by pressure feedback control as described above. When it does not coincide with SB or does not converge, it can be determined that an abnormal situation in which pressure cannot be adjusted has occurred on the factory power source 140, 154 side, and an alarm can be sent to the system controller or the like by interlocking.

  This embodiment has a function capable of appropriately responding (adapting) even when the main control unit 152 cannot obtain data on the thickness of each substrate G from the outside. That is, a means or mechanism for measuring the thickness of each substrate G in the resist coating unit (CT) 40 is provided.

As shown in FIG. 3 to FIG. 5 and FIG. 11, the upper optical distance sensor 170 facing downward is integrally formed with the nozzle 78 on one side surface or one side thereof (preferably on the upstream side of conveyance or the loading portion M ₁ side). It is attached. The upper optical distance sensor 170 projects a light beam LB ₁ toward the substrate G immediately below, receives reflected light from the upper surface of the substrate G, and receives a predetermined measurement reference height position H from the light receiving position. The measured value [L ₁ ] of the distance L ₁ between ₁ and the upper surface of the substrate G is obtained.

Further, as shown in FIGS. 3, 7 and 11, an upward lower optical distance sensor 172 is attached to the stage 76 side (preferably a position substantially facing the upper optical distance sensor 170). The lower optical distance sensor 172 emits a light beam LB ₂ toward the substrate G immediately above, receives reflected light from the lower surface of the substrate G, and receives a predetermined measurement reference height position H ₂ from the light receiving position. The measured value [L ₂ ] of the distance L ₂ between the substrate and the lower surface of the substrate G is obtained. Since the upper measurement reference height position Z ₁ and lower measurement reference height position Z ₂ is known, when the distance interval (Z ₁ -Z ₂₎ and L _a (known value), the measurement of the thickness of the substrate G The value [D _i ] is obtained by the following equation (1).
[D _i ] = L _a − ([L ₁ ] + [L ₂ ]) (1)

The main control unit 152 reads the pressure setting values A _i and B _i for the substrate G with reference to the data table (FIG. 12) based on the substrate thickness measurement value [D _i ] obtained as described above, Optimal reference values SA _i and SB _i can be given to the valve controller 150 of the compressed air supply mechanism and the valve controller 164 of the vacuum supply mechanism, respectively. Since the thickness measurement value [D _i ] may not exactly match the standard thickness D _{i due} to the individual difference (variation) of the substrate G, the data table has a value closest to the thickness measurement value [D _i ]. Reference may be made to the standard thickness D _i .

  In the illustrated configuration example, a pair of upper and lower optical distance sensors 170 and 172 are provided on the left and right sides, respectively, and the thicknesses of the left and right ends of the substrate G are measured, and the average value of both is obtained.

Further, in this embodiment, by directly measuring the substrate flying height H _b at stage coating area M _3, the feedback control to the compressed air supply mechanism and the vacuum supply mechanism so that the measured value matches the flying height set value H _S It is also possible to apply. In order to directly measure the substrate flying height H _b , the distance measurement value [L ₂ ] obtained from the lower optical distance sensor 172 can be used. That is, since the height position Z ₃ on the upper surface of the stage 76 is constant (known value), the distance interval (Z ₃ −Z ₂ ) between it and the lower measurement reference height position Z ₂ is set to L _b (known value). ) and when the measured value of the substrate flying height H _b [H _b] is obtained by the following equation (2).
[H _b ] = [L ₂ ] −L _b (2)

The main control unit 152 sets the pressure setting values A _i and B _i calculated from the data table (FIG. 12) as described above as initial values, and then uses the substrate flying height measurement value [H _b ] as the flying height setting value H _S. When there is an error, the pressure setting values A and B for feedback control are variably adjusted with a predetermined algorithm so that the comparison error is zero.

FIG. 13 shows a preferred algorithm for variably adjusting the pressure setting values A and B for feedback control. Usually, there is a relationship between the positive pressure set value A and the negative pressure set value B that the former absolute value | A | is greater than the latter absolute value | B |. That is, in order to float the substrate G on the stage 76, the air pressure at the ejection port 88 must be larger than the vacuum pressure at the suction port 90. According to the algorithm of this embodiment, the positive pressure set values A, A of feedback control are maintained while maintaining the same ratio as the ratio | A _i |: | B _i | between the initial set values A _i and B _i read from the data table. The negative pressure set value B is variably adjusted. Assuming that the combined levitation pressure F applied to the substrate G is proportional to the difference between the absolute values of the positive pressure set value A and the negative pressure set value B (| A |-| B |), this algorithm results in the combined levitation pressure F Can be finely variably adjusted on a straight line with a constant rate of change (gradient).

Next, the coating processing operation in the resist coating unit (CT) 40 of this embodiment will be described. In the following description, the substrate flying height H _b is measured as described above in order to keep the substrate flying height H _b in the application region M ₃ of the stage 76 (particularly immediately below the nozzle 78) near the set value H _S. It is assumed that a method of matching the flying height measurement value [H _b ] with the flying height setting value H _S by feedback control is used.

When the transport device 54 new substrate G (FIG. 1) than the untreated is carried into the carry-area M ₁ stage 76, the lift pins 86 receives the substrate G at the forward position. After conveying device 54 has exited, the lift pins 86 are lowered down to a height position that is floating position H _a for conveying the substrate G (Figure 5). Next, an alignment unit (not shown) is operated, and a pressing member (not shown) is pressed against the floating substrate G from four directions to align the substrate G on the stage 76. When the alignment operation is completed, immediately after that, the suction pad 104 is raised from the original position (retracted position) to the forward movement position (joined position) in the substrate transport section 84. The suction pad 104 is vacuum-on from before, and is bonded by a vacuum suction force as soon as it comes into contact with the side edge of the floating substrate G. Immediately after the suction pad 104 is coupled to the side edge of the substrate G, the alignment unit retracts the pressing member to a predetermined position.

Next, the substrate transport unit 84 moves the slider 98 straight from the transport start point position to the transport direction (X direction) at a relatively high constant speed while holding the side edge of the substrate G by the holding unit 102. Thus straight movement in the conveying direction (X direction) in a state where the substrate G is floated on the stage 76, as shown in (A) of FIG. 14, the front end is within the coating area M ₃ of the substrate G (more precisely The substrate transport unit 84 stops the first-stage substrate transport when it reaches a set position (near the nozzle 78). At this time, the resist nozzle 78 is located at a reference position that is considerably away from the substrate G.

When the substrate G is stopped, as shown in FIG. 14A, the upper optical distance sensor 170 is moved between a predetermined measurement reference height position Z ₁ and the upper surface of the substrate G by the optical measurement method as described above. to measure the distance L _1. On the other hand, the lower optical distance sensor 172 also measures the distance L ₂ between the predetermined measurement reference height position Z ₂ and the lower surface of the substrate G by the optical measurement method as described above. As a result, the main control unit 152 obtains the measured value [D _i ] of the thickness of the substrate G from the equation (1) as described above, and obtains the measured value [H _b ] of the substrate flying height H _b from the equation (2). Can be sought. Then, referring to the data table (FIG. 12), the pressure setting values A _i and B _i corresponding to the substrate thickness measurement values [D _i ] are read, and the reference values SA _i and SB _i corresponding to them are supplied with compressed air. This is applied to the valve controller 150 of the mechanism and the valve controller 164 of the vacuum supply mechanism, respectively. Then, the substrate flying height measurement value [H _b ] based on the distance measurement value [L ₂ ] from the lower optical distance sensor 172 is fed back, and the pressure setting values A and B or the reference values A and B are as described above. Variable control is performed according to the algorithm, and the substrate flying height measurement value [H _b ] is made to coincide with the vicinity of the flying height setting value H _S.

In this way, after the substrate flying height _Hb near the resist nozzle 78 is made to coincide with the flying height set value H _S , the main control unit 152 sets the distance interval between the nozzle 78 and the substrate G, that is, the coating gap S as the set value ( 100 μm), the resist nozzle 78 is lowered to a predetermined height position through the nozzle lifting / lowering portion 138 (FIG. 11). The lower end of the resist nozzle 78 Z ₄ in the original position shown in FIG. 14 (A) the height position of (discharge ports) (known value), when Z ₅ after the drop nozzle drop distance DZ is the following formula ( Given in 3).
DZ = Z ₄ −Z ₅
= Z ₄ − (S + [D _i ] + H _b + Z ₃ ) (3)

After the coating gap S is adjusted to the set value (100 μm) in this way, the resist solution supply mechanism starts discharging the resist solution R from the resist nozzle 78 toward the upper surface of the substrate G under the control of the main control unit 152. At this time, it is preferable to start discharging at a normal flow rate after first discharging a small amount of resist solution R to completely close the gap S between the nozzle discharge port and the substrate G. On the other hand, the substrate transport unit 84 starts the second-stage substrate transport. In this second stage, that is, the substrate conveyance at the time of application is performed at a relatively low constant speed. Thus, in the coating region M ₃ , the substrate G moves at a constant speed in the transport direction (X direction) with a constant flying height while maintaining a horizontal posture, and at the same time, the long resist nozzle 78 faces the substrate G directly below. By discharging the resist solution R in a strip shape at a constant flow rate, a resist solution coating film MR is formed from the front end side to the rear end side of the substrate G as shown in FIG. .

Even if a large fluctuation occurs in the pressure of the factory force (air pressure and / or vacuum pressure) during the resist coating process, the stage coating region M _{3 is} controlled by the above floating pressure control mechanism (FIGS. 11 to 13). Since the flying height _Hb of the substrate G (particularly immediately below the resist nozzle 78) is stably maintained with high accuracy in the vicinity of the set value H _S , the coating gap S is maintained at the set value and at the same time the substrate G is horizontal. Therefore, the resist film MR having a uniform film thickness with no coating unevenness is formed on the substrate G.

When the above-described coating process is completed in the coating region M ₃ , that is, when the rear end portion of the substrate G passes just below the resist nozzle 78, the resist solution supply mechanism ends the discharge of the resist solution R from the resist nozzle 78. . Immediately after that, the nozzle elevating part 138 lifts the resist nozzle 78 vertically upward and retracts it from the substrate G. On the other hand, the substrate transport unit 84 switches to the third stage substrate transport with a relatively high transport speed. When the substrate G arrives at the conveying end position in the unloading area M _5, the substrate conveying unit 84 to stop the substrate carrying the third stage. Immediately after this, the supply of the vacuum to the suction pad 104 is stopped, and the suction pad 104 descends from the forward movement position (coupling position) to the original position (retraction position) and is separated from both end portions of the substrate G. Instead, the lift pins 92 rise from the original position below the stage to the forward movement position above the stage in order to unload the substrate G.

Thereafter, the unloader, that is, the transfer arm 74 accesses the unloading area M ₅ , receives the substrate G from the lift pins 92, and unloads it out of the stage 76. The substrate transport unit 84 immediately returns the substrate G to the loading region M ₁ at a high speed when the substrate G is transferred to the lift pins 92. When the processed substrate G is unloaded as described above in the unloading area M ₅ , loading, alignment, or transfer start is performed on the new substrate G to be subjected to the next coating process in the loading area M ₁ .

As described above, in this embodiment, the carry-in area M ₁ , the coating area M ₃ , and the carry-out area M ₅ are separately provided on the stage 76, and the substrate is sequentially transferred to each of these areas to carry out the substrate carry-in operation, resist The liquid supply operation and the substrate unloading operation are performed independently or in parallel in each region, whereby the time (T _IN ) required for the operation of loading one substrate G onto the stage 76 and the stage 76 The total time required for one cycle of the coating process in which the time required for transporting from the carry-in area M ₁ to the carry-out area M ₅ (T _C ) and the time required for carrying out from the carry-out area M ₅ (T _OUT ) are added. Tact time can be shortened more than (T _C + T _IN + T _OUT ).

  In addition, the substrate G is floated in the air by using the pressure of the gas ejected from the ejection port 88 provided on the upper surface of the stage 76, and the substrate G is transported from the long resist nozzle 78 while the floating substrate G is conveyed on the stage 76. Since the resist solution is supplied and applied onto G, it is possible to efficiently cope with an increase in the size of the substrate.

Even if a large fluctuation occurs in the pressure of the factory force used for the substrate floating conveyance, the flying height _Hb of the substrate G in the coating region M ₃ of the stage 76 (particularly immediately below the resist nozzle 78) is high near the set value H _S. Since it can be held stably with high accuracy, a resist film having a constant thickness without application unevenness can be formed on the substrate G.

  The preferred embodiment of the present invention has been described above, but the present invention is not limited to the above embodiment, and various modifications can be made within the scope of the technical idea.

  For example, in the levitation pressure control mechanism of the above-described embodiment, a blower fan 180 is provided in the middle of the vacuum pipe 156 as shown in FIG. 15 instead of the conductance valve 160 in order to control the vacuum pressure. It is also possible to feedback control the rotation amount of the blower fan 180 and hence the pressure on the secondary side (intake side) of the blower fan 180 by the blower controller 184 through the inverter 182 that drives the fan. In this case, the vacuum factory power source 154 can be replaced with an exhaust duct or the like. In the above-described embodiment, the feedback control is performed simultaneously in both the compressed air system and the vacuum system. However, it is possible to perform the feedback control on only one side.

  In the above-described embodiment, in order to measure the thickness of the substrate G in the resist coating unit (CT) 40, the upper optical distance sensor 170 that measures the distance from the upper surface of the substrate G and the lower surface of the substrate G A lower optical distance sensor 172 for measuring the distance was used. However, a light beam is applied to the substrate G from above, and the reflected light from the upper surface of the substrate G and the reflected light from the lower surface (back surface) of the substrate G are received. It is also possible to measure this. Alternatively, a light beam is applied to the substrate G from below, and the reflected light from the lower surface of the substrate G and the reflected light from the upper surface (front surface) of the substrate G are received. A method of measuring the thickness of G is also possible.

  In the mechanism in which the resist nozzle 78 is supported or moved up and down in the vertical direction, it is possible to attach the resist nozzle 78 to a horizontal beam-like nozzle support member and connect the nozzle support member to the drive shaft of the lift drive unit. It is. In that case, an optical distance sensor or a substrate thickness measurement sensor can be attached to the nozzle support member.

  The holding unit 102 of the substrate transport unit 84 in the above-described embodiment has the vacuum suction type pad 104, but a pad that holds the side edge of the substrate G mechanically (for example, tightly) is also possible. It is. Various systems and configurations can be employed for the mechanism for detachably coupling the pad 104 to the side edge of the substrate G. Moreover, although the board | substrate conveyance part 84 in the said embodiment hold | maintained and conveyed the right and left both-sides edge part of the board | substrate G, it is also possible to hold | maintain only the one side edge part of the board | substrate G, and to carry a board | substrate.

  The above-described embodiment relates to a resist coating apparatus in a coating / development processing system for LCD manufacturing. However, the present invention is applicable to any processing apparatus or application that supplies a processing liquid onto a substrate to be processed. Therefore, as the processing liquid in the present invention, in addition to the resist liquid, for example, a coating liquid such as an interlayer insulating material, a dielectric material, and a wiring material can be used, and a developing liquid or a rinsing liquid can also be used. 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, glass substrates, photomasks, printed substrates, and the like are 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 procedure of the process in the application | coating development processing system of embodiment. It is a schematic plan view showing the entire configuration of a resist coating unit and a vacuum drying unit in the coating and developing treatment system of the embodiment. It is a perspective view which shows the whole structure of the resist coating unit in embodiment. It is a schematic front view which shows the whole structure of the resist coating unit in embodiment. It is a top view which shows an example of the array pattern of the jet nozzle and suction inlet in the stage application | coating area | region in the said resist application unit. It is a partial cross section schematic side view which shows the structure of the board | substrate conveyance part in the said resist application unit. It is an expanded sectional view which shows the structure of the holding | maintenance part of the board | substrate conveyance part in the said resist application unit. It is a perspective view which shows the structure of the pad part of the board | substrate conveyance part in the said resist application unit. It is a perspective view which shows one modification of the holding | maintenance part of the board | substrate conveyance part in the said resist application unit. It is a block diagram which shows the structure of the flying pressure control mechanism in the said resist application unit. It is a figure which shows an example of the data table used with the said levitation pressure control mechanism. It is a figure which shows an example of the algorithm of the setting pressure variable control used with the said levitation pressure control mechanism. It is an enlarged side view which shows the effect | action of the said floating pressure control mechanism in the said resist application unit. It is a block diagram showing the composition of the levitation pressure control mechanism by one modification of an embodiment.

Explanation of symbols

40 resist coating unit (CT)
76 Stage 78 Registration nozzle 84 Substrate transport unit 85 Loading lift pin lifting unit 86 Loading lift pin 88 Jet port 90 Suction port 100 Transport drive unit 102 Holding unit 104 Adsorption pad 138 Nozzle lifting unit 140 Compressed air source 142 Compressed air supply pipe 146 Proportional Control valve 148 Pressure sensor 150 Valve controller 152 Main controller 154 Vacuum source 156 Vacuum pipe 160 Conductance valve 162 Pressure sensor 164 Valve controller 170 Upper optical distance sensor 172 Lower optical distance sensor 180 Blower fan 182 Inverter 184 Blower controller M ₁ Carry in area M ₃ application area M ₅ carry-out area

Claims (20)

A stage having a first levitation region provided with a mixture of a number of jets for ejecting gas and a number of suction ports for sucking gas;
A substrate transfer section that passes the first floating region in a predetermined transfer direction in a state where the substrate to be processed is floated on the stage;
A processing liquid supply unit that has a nozzle disposed above the first floating region, and discharges the processing liquid from the nozzle to supply the processing liquid onto the substrate;
The pressure of the gas supplied to the jet port and the pressure of the vacuum supplied to the suction port so as to coincide with or approximate the pressure set value corresponding to the set flying height of the substrate on the stage in the first flying region And a levitation control unit for controlling at least one of the substrate processing apparatus. The levitation control unit is
A proportional control valve provided in the middle of a gas supply path connecting a supply source of positive pressure gas and the jet port;
A first pressure measuring unit for measuring a secondary pressure of the proportional control valve;
2. A first valve control unit that controls an opening degree of the proportional control valve so that a secondary pressure measurement value obtained from the first pressure measurement unit matches a first pressure set value. 2. The substrate processing apparatus according to 1.   The substrate processing apparatus according to claim 2, wherein the levitation control unit includes a first pressure setting unit that provides the first pressure setting value according to a thickness of the substrate. The levitation control unit is
A conductance valve provided in the middle of the exhaust path connecting the negative pressure source and the suction port;
A second pressure measuring unit for measuring a secondary pressure of the conductance valve;
2. A second valve control unit that controls the opening of the conductance valve so that a secondary pressure measurement value obtained from the second pressure measurement unit matches a second pressure set value. 4. The substrate processing apparatus according to claim 3. The levitation control unit is
A blower fan connected to the suction port via an exhaust path;
A second pressure measuring unit for measuring the pressure in the exhaust passage;
The blower control part which controls the rotation amount of the said blower fan so that the pressure measurement value obtained from the said 2nd pressure measurement part may correspond with a 2nd pressure setting value. 2. The substrate processing apparatus according to 1.   The substrate processing apparatus according to claim 4, wherein the levitation control unit includes a second pressure setting unit that gives the second pressure setting value according to the thickness of the substrate.   The substrate processing apparatus according to claim 3, further comprising a substrate thickness measuring unit that optically measures the thickness of the substrate on the stage. A stage having a first levitation region provided with a mixture of a number of jets for ejecting gas and a number of suction ports for sucking gas;
A substrate transfer section that passes the first floating region in a predetermined transfer direction in a state where the substrate to be processed is floated on the stage;
A processing liquid supply unit that has a nozzle disposed above the first floating region, and discharges the processing liquid from the nozzle to supply the processing liquid onto the substrate;
A flying height measuring unit that measures the flying height of the substrate on the stage in the first flying region;
A levitation control unit that controls at least one of the pressure of the gas supplied to the jet port and the pressure of the vacuum supplied to the suction port so that the measured value of the levitation amount obtained from the levitation amount measurement unit matches the set levitation amount And a substrate processing apparatus. The levitation control unit is
A proportional control valve provided in the middle of a gas supply path connecting a supply source of positive pressure gas and the jet port;
A first pressure measuring unit for measuring a secondary pressure of the proportional control valve;
A first valve control unit for controlling an opening of the proportional control valve so that a secondary pressure measurement value obtained from the first pressure measurement unit matches a first pressure set value;
The substrate processing apparatus according to claim 8, further comprising: a first pressure setting unit that variably controls the first pressure set value so that the measured flying height matches the set flying height. The levitation control unit is
A conductance valve provided in the middle of the exhaust path connecting the negative pressure source and the suction port;
A second pressure measuring unit for measuring a secondary pressure of the conductance valve;
A second valve control unit that controls the opening of the conductance valve so that a secondary pressure measurement value obtained from the second pressure measurement unit matches a second pressure setting value;
The substrate processing apparatus according to claim 8, further comprising: a second pressure setting unit that variably controls the second pressure setting value so that the measured flying height matches the set flying height. The levitation control unit is
A blower fan connected to the suction port via an exhaust path;
A second pressure measuring unit for measuring the pressure in the exhaust passage;
A blower control unit that controls a rotation amount of the blower fan so that a pressure measurement value obtained from the second pressure measurement unit matches a second pressure setting value;
The substrate processing apparatus according to claim 8, further comprising: a second pressure setting unit that variably controls the second pressure setting value so that the measured flying height matches the set flying height.   The substrate processing apparatus according to claim 8, wherein the flying height measurement unit includes an optical distance sensor for optically measuring a distance between the substrate and the upper surface of the stage.   The substrate processing apparatus as described in any one of Claims 1-12 which has a nozzle raising-lowering part for raising / lowering the said nozzle in a perpendicular direction.   The substrate processing apparatus according to claim 1, wherein the stage has a second floating region that floats the substrate upstream of the first floating region in the transport direction.   The substrate processing apparatus according to claim 14, wherein a loading unit for loading the substrate is provided in the second floating region.   The substrate processing apparatus according to claim 1, wherein the stage has a third floating region that floats the substrate on the downstream side of the first floating region in the transport direction.   The substrate processing apparatus according to claim 16, wherein an unloading unit for unloading the substrate is provided in the third floating region. The substrate transport unit is
A guide rail disposed on one or both sides of the stage so as to extend in parallel with the direction of movement of the substrate;
A slider movable along the guide rail;
A transport driving unit that drives the slider to move along the guide rail;
The substrate processing apparatus according to claim 1, further comprising: a holding portion that extends from the slider toward a center portion of the stage and detachably holds a side edge portion of the substrate. Along the transport direction on the stage, set the loading area larger than the substrate to be processed, the coating area smaller than the substrate, and the unloading area larger than the substrate in this order in a row,
The substrate is floated by the pressure of gas ejected from a number of jets provided on the upper surface of the stage, and at least in the coating region, a plurality of suction ports mixed with the jets are provided on the upper surface of the stage. Controlling the balance between the vertical upward pressure applied from the jet port and the vertical downward pressure applied from the suction port to the substrate passing through the substrate, and giving the substrate a substantially uniform levitation force;
The pressure of the gas supplied to the jet port and the pressure of the vacuum supplied to the suction port so as to coincide with or approximate the pressure set value corresponding to the set flying height of the substrate on the stage in the first flying region Control at least one of
A substrate processing method for applying the processing liquid onto the substrate by discharging the processing liquid from a nozzle disposed above in the application area during the transfer of the substrate from the carry-in area to the carry-out area. Along the transport direction on the stage, set the loading area larger than the substrate to be processed, the coating area smaller than the substrate, and the unloading area larger than the substrate in this order in a row,
The substrate is floated by the pressure of gas ejected from a number of jets provided on the upper surface of the stage, and at least in the coating region, a plurality of suction ports mixed with the jets are provided on the upper surface of the stage. Controlling the balance between the vertical upward pressure applied from the jet port and the vertical downward pressure applied from the suction port to the substrate passing through the substrate, and giving the substrate a substantially uniform levitation force;
Measure the flying height of the substrate on the stage in the application area,
Controlling at least one of the pressure of the gas supplied to the jet port and the pressure of the vacuum supplied to the suction port so that the measured value of the substrate flying height matches or approximates the set flying height;
A substrate processing method for applying the processing liquid onto the substrate by discharging the processing liquid from a nozzle disposed above in the application area during the transfer of the substrate from the carry-in area to the carry-out area.

Images