JP4398786B2 - Coating method and coating apparatus - Google Patents

Description

  The present invention relates to a coating method and a coating apparatus for forming a coating film by coating a liquid on a substrate to be processed.

  Conventionally, in a photolithography process in a manufacturing process of an LCD, a semiconductor device or the like, as a type of a resist nozzle used for applying a resist solution on a substrate to be processed (glass substrate, semiconductor wafer, etc.), for example, in Patent Document 1 A long or slit type nozzle having a slit-like discharge port as disclosed is known.

  In a coating apparatus using such a slit type resist nozzle, several hundred μm or less is provided between the upper surface (surface to be processed) of the substrate placed horizontally on the mounting table or holding plate and the discharge port at the lower end of the nozzle. And a resist solution is discharged toward the upper surface of the substrate while moving the resist nozzle horizontally relative to the substrate above the substrate. At this time, the resist solution overflowing from the discharge port is flattened at the lower end of the nozzle that moves horizontally to form a resist solution coating film on the substrate with a constant film thickness. As described above, the gap between the lower end of the nozzle and the upper surface of the substrate is an important parameter that affects the film thickness of the coating film and the resist consumption, and it is necessary to maintain or manage the gap at a constant value.

Therefore, in the conventional coating apparatus, a large number of vacuum suction ports that operate independently are provided on the mounting table, and gaps between the lower end of the nozzle and the upper surface of the substrate are formed at a plurality of representative points set discretely on the substrate. For a portion where the gap is detected from the gap sensor and the gap is deviated from the set value, the substrate is warped or distorted by adjusting the vacuum suction force by the vacuum suction port in the vicinity thereof. This type of gap sensor is configured as an optical distance sensor, and emits a light beam vertically downward from a light projecting element made of, for example, a semiconductor laser or a light emitting diode toward the upper surface of the substrate, and collects reflected light from the upper surface of the substrate. An image is formed on a position detection element through a lens, and a distance interval, that is, a gap size is obtained from the image formation position.
JP-A-8-138991

  The conventional coating apparatus as described above can cope with warping and distortion of the substrate itself by correcting it with a vacuum adsorption force, but foreign matter (particles, dust, debris, etc.) adhering to the upper surface of the substrate. In addition, it is difficult to safely deal with foreign matters sandwiched between the substrate and the mounting table. That is, as described above, when the resist nozzle moves horizontally relative to the substrate with a gap within several hundred μm from the upper surface of the substrate, foreign matter close to or larger than the size of the gap adheres to the upper surface of the substrate. If it does, the lower end part or discharge part of a resist nozzle will rub the upper surface of a board | substrate through a foreign material. Alternatively, if a foreign object is sandwiched between the substrate and the mounting table, the substrate swells in the vicinity thereof, and there is a problem that the discharge portion of the resist nozzle hits the upper surface of the substrate and rubs. When the discharge portion of the resist nozzle rubs the substrate in this way, not only the substrate loses its product value, but also the very expensive resist nozzle is damaged or broken and cannot be used.

  In addition, the gap sensor in the conventional coating apparatus detects a gap at one point at a time, and it is difficult to reliably detect a foreign substance that may exist at an indefinite position on the substrate. In addition, unlike the case where the substrate itself is warped, if the substrate is warped by a foreign object sandwiched between the substrate and the mounting table, the vacuum suction force in the vicinity of the mounting table is adjusted in any way. However, the upper surface of the substrate cannot be flattened, and it is difficult to avoid contact or sliding contact between the resist nozzle and the substrate.

  The present invention has been made in view of the problems of the prior art, and a coating method for safely performing a coating operation in which a nozzle is scanned at an upper surface of a substrate to be processed or at a height position close to the surface to be processed. The main purpose is to provide a coating apparatus.

In order to achieve the above object, the coating method of the present invention is such that a substrate to be processed is floated horizontally at a first height position by applying a gas pressure from below , and the substrate is positioned close to the top toward the substrate. A coating method in which a coating scan is performed by relative movement in a horizontal direction between a nozzle that discharges a coating solution from the substrate and the substrate, and the coating solution is applied to the upper surface of the substrate , and the coating scan is performed before the coating scan. And horizontally traverses the vicinity of the upper surface of the substrate floating at the first height position at a second height position corresponding to the height position of the gap formed between the nozzle and the substrate. As described above, a light beam having a beam diameter corresponding to the size of the gap is emitted from a light beam emitting unit, and the light receiving unit is disposed at a position facing the light beam emitting unit across the substrate. receiving light beams corresponding to the light intensity Converting the level of the voltage signal, moving said light beam emitting unit and the light receiving portion with relatively the nozzle relative to the substrate in front of the nozzle in the direction of the coating scanning, output from the light receiving portion The level of the voltage signal is compared with a predetermined reference value, and based on the comparison result, the presence or absence of a substantial obstacle at the second height position is determined, and according to the determination result, Execution, stop or interruption of the application scan on the substrate is selected.

First coating apparatus of the present invention includes a floating support portion for floating horizontally in the first height position by applying a pressure of the gas to be treated substrate from below, the first height position by the floating support portion in the nozzle from the supported upward proximity toward the substrate is positioned for discharging a coating solution, to perform relative movement in the horizontal direction between the upper in the substrate and the nozzle of the substrate And a coating scanning section for supporting the vicinity of the upper surface of the substrate supported at the first height position by the floating support section according to the height position of the gap formed between the nozzle and the substrate A light beam emitting unit that emits a highly directional light beam having a beam diameter corresponding to the size of the gap so as to cross horizontally at the second height position, and the light beam emitting unit across the substrate, The light beam is disposed at the opposite position A light receiving section for converting the level of the voltage signal corresponding to the light intensity received, relative the to the substrate the light beam emitting unit and the light receiving portion in front of the nozzle in the direction of the applied scanning The monitor scanning unit for moving together with the nozzle, and the level of the voltage signal output from the light receiving unit is compared with a predetermined reference value, and based on the comparison result, the second scanning position at the second height position. A first determination unit that determines the presence or absence of a substantial obstacle, and a scan control unit that selects execution, suspension, or interruption of scanning of the nozzle with respect to the substrate according to a determination result in the first determination unit. .
The second coating apparatus of the present invention, mixed with large number of gas ejection holes for applying pressure vertically upward blown a high pressure gas to the lower surface of the substrate, and the gas ejection holes at a constant density A plurality of gas suction holes which are arranged in an arrangement pattern and apply downward pressure by suction to the lower surface of the substrate; and the gas ejection holes for maintaining the height position of the substrate at the first height position. A levitation control unit that balances the vertical upward pressure applied to the substrate and the downward pressure applied to the substrate from the gas suction hole, and an upper proximity toward the substrate supported by the support unit Supported by the support unit, a nozzle for discharging the coating liquid from the position, a coating scanning unit for causing a relative movement in the horizontal direction between the nozzle and the substrate above the substrate, and The substrate Directivity having a beam diameter corresponding to the size of the gap so as to horizontally traverse the vicinity of the upper surface horizontally at a second height position corresponding to the height position of the gap formed between the nozzle and the substrate. A light beam emitting part that emits a high light beam and a position that faces the light beam emitting part across the substrate, receives the light beam, and converts it to a voltage signal of a level according to the light intensity. A light receiving section, a monitor scanning section for moving the light beam emitting section and the light receiving section together with the nozzle relative to the substrate in front of the nozzle in the coating scanning direction; and the light receiving section A first determination unit that compares the level of the voltage signal output from a predetermined reference value and determines the presence or absence of a substantial obstacle at the second height position based on the comparison result; The first Execution of scanning of the nozzle relative to the substrate according to the determination result by the determination unit, and a scanning control unit for selecting a stop or interruption.

In the present invention, coating processing by coating scanning is performed in a state where the substrate to be processed is floated. In order to horizontally support the floating substrate at the first height position, a high-pressure gas is sprayed from the gas ejection hole to the lower surface of the substrate, and at the same time, a suction force is applied from the suction hole to It is preferable to balance the pressure and the downward pressure. In this regard, a second coating apparatus of the present invention is mixed with a constant density and large number of gas ejection holes for applying pressure vertically upward blown a high pressure gas to the lower surface of the substrate to be processed, a gas ejection hole A plurality of gas suction holes that are arranged in an arrangement pattern that applies downward pressure by suction to the lower surface of the substrate, and the substrate from the gas ejection holes to maintain the height position of the substrate at the first height position. The levitation support unit is configured by a levitation control unit that balances the vertical upward pressure applied to the substrate and the downward pressure applied to the substrate from the gas suction hole.

When coating scanning is performed, prior to that, that is, in front of the nozzles in the coating scanning direction, the light beam emitting unit and the light receiving unit facing each other across the substrate are positioned near the upper surface of the substrate at the second height position. The beam of light that should be traversed horizontally is exchanged. In this case, if a foreign object adheres somewhere on the substrate, the light beam is blocked by the foreign object during the monitor scanning process, and the level of the voltage signal output from the light receiving unit is blocked by the light beam. Decreases depending on

Here, the degree to which the light beam is blocked depends on the size of the foreign matter and the beam diameter and height position of the light beam. In the present invention, the second height position is set according to the height position of the gap formed between the substrate and the nozzle (preferably so as to match or approximate the center height position of the gap). The The beam diameter of the light beam is set according to the size of the gap (preferably so as to match or approximate the size of the gap).

In the present invention, the level of the voltage signal output from the light receiving unit is compared with a predetermined reference value. In this comparison, it is determined that the voltage signal level is normal while the level of the voltage signal does not fall below a predetermined ratio (for example, 50%) with respect to the reference value, and the application scanning is executed or continued. However, when the level of the voltage signal falls below the predetermined ratio with respect to the reference value, it is determined at that time that the degree of light beam blocking exceeds a certain upper limit. That is, it is determined that there is a foreign object (substantial obstacle) that may interfere with the application scanning. When this determination result is obtained, the application scanning is stopped or interrupted. Thus, when there is an obstacle in front of the application scan near the upper part of the substrate, the application scan can be stopped before the nozzle arrives to avoid contact between the nozzle and the obstacle.

In addition, in the invention, even if the nozzle contacts the substrate through a foreign object , the floating substrate can be displaced downward by the pressing force from the nozzle side , so that damage to both due to contact is minimal. You can do everything.

  According to one aspect of the coating apparatus of the present invention, the imaging unit that images the upper surface of the substrate after the coating liquid is applied, and the coating film on the substrate by image recognition based on the image signal obtained by the imaging unit. And a determination unit that determines whether or not substantial spots (unevenness) exist. In general, when spots occur in the coating film, it is almost always caused by clogging of the nozzle. Therefore, by checking whether the coating film has spots after the coating process, Simultaneously with the inspection, the coating liquid discharge function of the nozzle can be inspected. Therefore, it is preferable that a determination result that a substantial spot exists on the upper surface of the substrate in the nozzle refresh unit for performing processing for recovering the coating liquid discharge function of the nozzle to a normal state and the determination unit is output. It is preferable to provide a refresh control unit that causes the nozzle refresh unit to perform a recovery process at the same time.

  According to the coating method or the coating apparatus of the present invention, by the configuration and operation as described above, the coating operation for scanning the nozzle at the upper surface of the substrate to be processed or the height position close to the surface to be processed is safely performed. The safety of the nozzle can be guaranteed.

  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 coating method and the coating apparatus of the present invention can be applied. This coating / development processing system 10 is installed in a clean room. For example, an LCD substrate is 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 are performed in the LCD manufacturing process. Is what you do. The exposure process is performed by an external exposure apparatus 12 installed adjacent to the processing 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 up to four cassettes C can be accommodated in a horizontal direction, for example, in the Y direction by stacking square glass substrates G in multiple stages. A cassette stage 20 that can be placed side by side and a transport mechanism 22 that puts and removes the substrate G to and from the cassette C on the stage 20 are provided. The transport mechanism 22 has a means for holding the substrate G, for example, a transport arm 22a, and can be operated with four axes of X, Y, Z, and θ. Delivery is now possible.

  In the process station (P / S) 16, the processing units are arranged in the order of the process flow or process on a pair of parallel and opposite lines A and B extending in the 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 cleaning process unit 24, a first thermal processing unit 26, and The coating process section 28 and the second thermal processing section 30 are arranged in a horizontal row. 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 second thermal processing unit 30, a development processing unit 32, and a decolorization process are provided. The unit 34 and the third thermal processing unit 36 are arranged in a horizontal row. In this line configuration, the second thermal processing unit 30 is located at the end of the upstream process line A and at the beginning of the downstream process line B, and straddles between both lines A and B. ing.

  An auxiliary transfer space 38 is provided between the process lines A and B, and a shuttle 40 that can horizontally place the substrate G in units of one sheet is bidirectional in the line direction (X direction) by a drive mechanism (not shown). Can be moved to.

  In the upstream process line A, the cleaning process unit 24 includes a scrubber cleaning unit (SCR) 42, and an excimer is disposed at a location adjacent to the cassette station (C / S) 10 in the scrubber cleaning unit (SCR) 42. A UV irradiation unit (e-UV) 41 is arranged. The cleaning unit in the scrubber cleaning unit (SCR) 42 performs brushing cleaning and blow cleaning on the upper surface (surface to be processed) of the substrate G while transporting the substrate G in the horizontal direction A by roller transport or belt transport. It has become.

  The first thermal processing unit 26 adjacent to the downstream side of the cleaning process unit 24 is provided with a vertical transfer mechanism 46 in the center along the process line A, and a plurality of single-wafer oven units are provided on both front and rear sides thereof. A multi-stage unit section or oven towers (TB) 44 and 48 are provided which are stacked in multiple stages together with a substrate transfer pass unit.

For example, as shown in FIG. 2, an upstream oven tower (TB) 44 includes a substrate carrying pass unit (PASS _L ) 50, dehydrating baking heating units (DHP) 52 and 54, and an adhesion unit. (AD) 56 are stacked in order from the bottom. Here, the pass unit (PASS _L ) 50 provides a space for carrying the substrate G after the cleaning process from the scrubber cleaning unit (SCR) 42 into the first thermal processing unit 26. In the oven tower (TB) 48 on the downstream side, a pass unit (PASS _R ) 60 for carrying out the substrate, cooling units (COL) 62 and 64 for adjusting the substrate temperature, and an adhesion unit (AD) 66 are arranged in order from the bottom. Stacked. Here, pass unit (PASS _R) 60 provides a space for unloading the substrate G having undergone the required heat treatment at a first thermal processing unit 26 to the downstream side of the coating process portion 28.

  In FIG. 2, the transport mechanism 46 includes a lift transport body 70 that can be moved up and down along a guide rail 68 that extends in the vertical direction, and a swivel transport body 72 that can rotate or turn in the θ direction on the lift transport body 70. And a transport arm or tweezers 74 that can move back and forth or extend and retract in the front-rear direction while supporting the substrate G on the revolving transport body 72. A drive unit 76 for driving the lifting and lowering conveyance body 70 up and down is provided on the base end side of the vertical guide rail 68, and a driving unit 78 for driving the swiveling conveyance body 72 to rotate is attached to the lifting and lowering conveyance body 70. A drive unit 80 for advancing and retracting 74 is attached to the rotary transport body 72. Each drive part 76,78,80 may be comprised by the electric motor etc., for example.

  The transport mechanism 46 configured as described above can access any unit in the oven towers (TB) 44 and 48 adjacent to each other by moving up and down at high speed, and the shuttle 40 on the auxiliary transport space 38 side. In both cases, the substrate G can be delivered.

  As shown in FIG. 1, the coating process unit 28 adjacent to the downstream side of the first thermal processing unit 26 includes a carry-in unit (IN) 81, a resist coating unit (CT) 82, a vacuum drying unit (VD) 84, The edge remover unit (ER) 86 and the carry-out unit (OUT) 87 are arranged in a line along the process line A. The configuration in the coating process unit 28 will be described in detail later.

  The second thermal processing unit 30 adjacent to the downstream side of the coating process unit 28 has the same configuration as that of the first thermal processing unit 26, and a vertical type between the process lines A and B. The transfer mechanism 90 is provided, one oven tower (TB) 88 is provided on the process line A side (last), and the other oven tower (TB) 92 is provided on the process line B side (lead).

Although not shown, for example, in the oven tower (TB) 88 on the process line A side, a substrate loading pass unit (PASS _L ) is disposed at the bottom, and a pre-baking heating unit (PREBAKE) is disposed thereon. For example, they may be stacked in three stages. Further, in the oven tower (TB) 92 on the process line B side, a pass unit (PASS _R ) for carrying out the substrate is disposed at the lowest stage, and a cooling unit (COL) for adjusting the substrate temperature is provided thereon, for example, one stage. The heating unit (PREBAKE) for pre-baking may be stacked thereon, for example, in a two-stage stack.

The transport mechanism 90 in the second thermal processing unit 30 includes the coating process unit 28 and the development process unit 32 via the pass units (PASS _L ) and (PASS _R ) of both oven towers (TB) 88 and 92. Not only can the substrates G be transferred in units of one sheet, but also the substrates G can be transferred in units of sheets to the shuttle 40 in the auxiliary transport space 38 and the interface station (I / F) 18 described later.

  In the downstream process line B, the development process unit 32 includes a so-called flat-flow development unit (DEV) 94 that performs a series of development processing steps while transporting the substrate G in a horizontal posture.

  A third thermal processing unit 36 is disposed downstream of the development process unit 32 with the decolorization process unit 34 interposed therebetween. The decoloring process unit 34 includes an i-ray UV irradiation unit (i-UV) 96 for performing a decoloring process by irradiating the surface to be processed of the substrate G with i-line (wavelength 365 nm).

  The third thermal processing unit 36 has the same configuration as that of the first thermal processing unit 26 and the second thermal processing unit 30, and the vertical transport mechanism 100 along the process line B. A pair of oven towers (TB) 98 and 102 are provided on both the front and rear sides.

Although not shown, for example, in the upstream oven tower (TB) 98, a pass unit (PASS _L ) for carrying a substrate is placed at the lowest stage, and a heating unit (POBAKE) for post-baking is placed thereon, for example. May be stacked in three stacks. Further, in the oven tower (TB) 102 on the downstream side, a post baking unit (POBAKE) is placed at the lowermost stage, and a pass cooling unit (PASS _R · COL) for carrying out and cooling the substrate is placed on the post baking unit (POSBAKE). The heating unit (POBAKE) for post-baking may be stacked in two layers.

The transport mechanism 100 in the third thermal processing unit 36 irradiates with i-line UV via the pass units (PASS _L ) and pass cooling units (PASS _R · COL) of both multi-stage unit parts (TB) 98 and 102. Not only can the unit (i-UV) 96 and cassette station (C / S) 14 and the substrate G be transferred in units of one sheet, but also the substrate G can be transferred in units of one unit to the shuttle 40 in the auxiliary transport space 38. ing.

  The interface station (I / F) 18 includes a transfer device 104 for exchanging the substrate G with the adjacent exposure device 12, and a buffer stage (BUF) 106 and an extension / cooling stage (EXT / COL) around the transfer device 104. ) 108 and peripheral device 110 are arranged. A stationary buffer cassette (not shown) is placed on the buffer stage (BUF) 106. The extension / cooling stage (EXT / COL) 108 is a stage for transferring a substrate having a cooling function, and is used when the substrate G is exchanged with the process station (P / S) 16 side. For example, the peripheral device 110 may have a configuration in which a titler (TITLER) and a peripheral exposure device (EE) are stacked vertically. The transfer device 104 has a means for holding the substrate G, for example, a transfer arm 104a, and transfers the substrate G to and from the adjacent exposure device 12, each unit (BUF) 106, (EXT / COL) 108, (TITLER / EE) 110. Can be done.

FIG. 3 shows a processing procedure 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 of the cassettes C on the stage 20, and the cleaning process unit 24 of the process station (P / S) 16. It is carried into the excimer UV irradiation unit (e-UV) 41 (step S ₁ ).

Excimer UV irradiation unit (e-UV) substrate G in the 41 is subjected to dry cleaning by UV irradiation (step S _2). This UV cleaning mainly removes organic substances on the substrate surface. After completion of the ultraviolet cleaning, the substrate G is moved to the scrubber cleaning unit (SCR) 42 of the cleaning process unit 24 by the transport mechanism 22 of the cassette station (C / S) 14.

In the scrubber cleaning unit (SCR) 42, as described above, the substrate G is brushed or blown onto the upper surface (surface to be processed) of the substrate G while being transported in a horizontal position in the horizontal direction by roller transport or belt transport. By performing cleaning, particulate dirt is removed from the substrate surface (step S ₃ ). After the cleaning, the substrate G is rinsed while being conveyed in a flat flow, and finally the substrate G is dried using an air knife or the like.

The substrate G that has been cleaned in the scrubber cleaning unit (SCR) 42 is carried into the pass unit (PASS _L ) 50 in the upstream oven tower (TB) 44 of the first thermal processing section 26 in a flat flow. The

In the first thermal processing unit 26, the substrate G is sequentially transferred to a predetermined oven unit in a predetermined sequence by the transport mechanism 46. For example, the substrate G is first transferred from the pass unit (PASS _L ) 50 to one of the heating units (DHP) 52 and 54, where it is subjected to dehydration (step S ₄ ). Next, the substrate G is transferred to one of the cooling units (COL) 62 and 64 where it is cooled to a constant substrate temperature (step S ₅ ). Thereafter, the substrate G is transferred to an adhesion unit (AD) 56 where it is subjected to a hydrophobic treatment (step S ₆ ). After completion of the hydrophobic treatment, the substrate G is cooled to a constant substrate temperature by one of the cooling units (COL) 62 and 64 (step S ₇ ). Finally, the substrate G is transferred to the pass unit (PASS _R ) 60 in the downstream oven tower (TB) 48.

  As described above, in the first thermal processing unit 26, the substrate G is arbitrarily transferred between the upstream multi-stage oven tower (TB) 44 and the downstream oven tower (TB) 48 via the transport mechanism 46. You can come and go. The second and third thermal processing units 30 and 36 perform the same substrate transfer operation.

The substrate G that has undergone the series of thermal or thermal processing as described above in the first thermal processing unit 26 is adjacent to the downstream side from the pass unit (PASS _R ) 60 in the downstream oven tower (TB) 48. The application process unit 28 is moved to the carry-in unit (IN) 81, and is moved from the carry-in unit (IN) 81 to the resist coating unit (CT) 82.

In the resist coating unit (CT) 82, the substrate G is coated with a resist solution on the upper surface (surface to be processed) by a spinless method using a slit type resist nozzle as will be described later. Next, the substrate G is subjected to a drying process by a decompression drying unit (VD) 84 adjacent to the downstream side, and an unnecessary (unnecessary) resist on the peripheral edge of the substrate is further removed by the edge remover unit (ER) 86 adjacent to the downstream side. It is removed (step S ₈ ).

The substrate G that has undergone the resist coating process as described above is transferred from the edge remover unit (ER) 86 to the pass unit (PASS _L ) in the upstream oven tower (TB) 88 of the adjacent second thermal processing unit 30. It is carried in.

Within the second thermal processing unit 30, the substrate G is sequentially transferred to a predetermined unit by the transport mechanism 90 in a predetermined sequence. For example, the substrate G is first transferred from the pass unit (PASS _L) to one of the heating units (PREBAKE), where it undergoes a heat treatment of pre-baking (Step S _9). Next, the substrate G is transferred to one of the cooling units (COL), where it is cooled to a constant substrate temperature (step S ₁₀ ). Thereafter, the substrate G passes through the pass unit (PASS _R ) on the downstream oven tower (TB) 92 side or without the extension cooling stage (EXT COL) on the interface station (I / F) 18 side. ) 108.

In the interface station (I / F) 18, the substrate G is transferred from the extension / cooling stage (EXT / COL) 108 to the peripheral exposure device (EE) of the peripheral device 110, where the resist adhering to the peripheral portion of the substrate G is removed. After receiving an exposure for removal during development, the image is sent to the adjacent exposure apparatus 12 (step S ₁₁ ).

In the exposure device 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 S ₁₁ ), it is first carried into a titler (TITLER) of the peripheral device 110, where it is placed on the substrate. Predetermined information is written in a predetermined part (step S ₁₂ ). Thereafter, the substrate G is returned to the extension / cooling stage (EXT / COL) 108. Transfer of the substrate G in the interface station (I / F) 18 and exchange of the substrate G with the exposure apparatus 12 is performed by the transfer device 104.

In the process station (P / S) 16, the transport mechanism 90 receives the exposed substrate G from the extension / cooling stage (EXT / COL) 108 in the second thermal processing unit 30, and the oven tower ( TB) is transferred to the developing process section 32 via the pass unit (PASS _R ) in the 92.

In the development process unit 32, the substrate G received from the pass unit (PASS _R ) in the oven tower (TB) 92 is carried into the development unit (DEV) 94. Substrate G in the developing unit (DEV) 94 is conveyed by the flat flow manner toward the downstream process line B, developing during the transport, rinse, a series of development processing step drying is performed (step S _13).

The substrate G subjected to the development process in the development process unit 32 is carried into the decolorization process unit 34 adjacent to the downstream side in a flat flow, where it is subjected to a decolorization process by i-line irradiation (step S ₁₄ ). The substrate G that has been subjected to the decoloring process is carried into the pass unit (PASS _L ) in the upstream oven tower (TB) 98 of the third thermal processing unit 36.

In the third thermal processing unit 36, the substrate G is transferred to the first one of the heating units (POBAKE) from the pass unit (PASS _L), where it undergoes a heat treatment of the post-baking (Step S _15). Next, the substrate G is transferred to a path cooling unit (PASS _R · COL) in the downstream oven tower (TB) 102, where it is cooled to a predetermined substrate temperature (step S ₁₆ ). The transport mechanism 100 transports the substrate G in the third thermal processing unit 36.

On the cassette station (C / S) 14 side, the transport mechanism 22 receives the substrate G that has completed all the steps of the coating and developing process from the pass cooling unit (PASS _R COL) of the third thermal processing unit 36, The received substrate G is accommodated in one of the cassettes C on the stage 20 (step S ₁ ).

  In the coating and developing treatment system 10, the present invention can be applied to the coating process unit 28, particularly the resist coating unit (CT) 82. Hereinafter, an embodiment in which the present invention is applied to the coating process section 28 will be described with reference to FIGS.

  As shown in FIG. 4, the coating process unit 28 has a carry-in unit (IN) 81, a resist coating unit (CT) 82, a vacuum drying unit (VD) 84, and an edge remover unit (ER) 86 on the support table 112. The carry-out units (OUT) 87 are arranged in a row in the X direction (along the process line A). A pair of guide rails 114, 114 extending in the X direction are laid in parallel on both ends of the support base 112, and a unit is formed by one or a plurality of pairs of transport arms 116, 116 that are guided by both guide rails 114, 114 and move. The substrate G can be exchanged between them.

The carry-in unit (IN) 81 is provided with a flat-flow type roller conveyance path 120 formed by laying rollers 118 on which the substrate G can be placed almost horizontally in the X direction at regular intervals. The roller conveyance path 120 is drawn from a pass unit (PASS _R ) 60 in the adjacent oven tower (TB) 48 and is driven by, for example, a conveyance driving unit 122 having a drive motor and a transmission mechanism. Below the roller conveyor line 120, and a plurality of lift pins 124 lift possible to hand them over to the carrier arm 116, 116 of the substrate G which is conveyed from the path unit (PASS _R) 60 lifted in a horizontal position is provided Yes. A substrate upper surface cleaner 126 for cleaning the upper surface of the substrate G is provided on the roller conveyance path 120, and the lower surface of the substrate G is cleaned at a position not interfering with the lift pins 124 under the roller conveyance path 120. A substrate bottom surface cleaner 128 (FIG. 6) is provided. The detailed configuration and operation of both cleaners 126 and 128 will be described later with reference to FIG. Note that the pass unit (PASS _R) 60, is transferred onto the roller conveyor line 120 receives the substrate G having undergone the required heat treatment at a first thermal processing unit 26 from the transport mechanism 46 (FIG. 2) Lift pins 130 that can be raised and lowered are provided.

  The resist coating unit (CT) 82 includes a stage 132 for horizontally placing and holding the substrate G, and a slit-type resist nozzle on the upper surface (surface to be processed) of the substrate G placed on the stage 132. There are spots on the coating processing unit 136 for applying a resist solution by a spinless method using 134, a stage cleaner 138 for cleaning the upper surface of the stage 132, and a coating film of the resist solution formed on the substrate G. A coating film inspection unit 140 for inspecting whether or not to perform, a nozzle refresh unit 142 for maintaining or refreshing the resist solution discharge function of the resist nozzle 134 in a normal state, and the like. The configuration and operation of each part in the resist coating unit (CT) 82 will be described in detail later with reference to FIGS.

  The vacuum drying unit (VD) 84 includes a tray or shallow container type lower chamber 144 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 144. (Not shown). The lower chamber 144 is substantially rectangular, and a stage 146 for placing and supporting the substrate G horizontally is disposed at the center, and exhaust ports 148 are provided at the four corners of the bottom surface. Each exhaust port 148 communicates with a vacuum pump (not shown) through an exhaust pipe (not shown). With the lower chamber 144 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.

  The edge remover unit (ER) 86 includes a stage 150 for horizontally mounting and supporting the substrate G, alignment means 152 for positioning the substrate G at a pair of opposite corners, and four sides of the substrate G. There are provided four remover heads 154 and the like for removing excess resist from the peripheral edge (edge). With the alignment means 152 positioning the substrate G on the stage 150, each remover head 154 moves along each side of the substrate G, and removes excess resist adhering to the peripheral portion of each side of the substrate with a thinner. It dissolves and is removed.

The carry-out unit (OUT) 87 has a roller conveyance path and lift pins (not shown) similar to those in the carry-in unit (IN) 81 described above. The transfer arms 116 and 116 transfer the substrate G, which has been subjected to the resist removal processing by the edge remover unit (ER) 86, to the carry-out unit (OUT) 87, and the lift pins receive the substrate G from the transfer arms 116 and 116 and are on the roller transfer path. To be transferred to. Thereafter, the substrate G is transported to the pass unit (PASS _L ) in the adjacent oven tower (TB) 88, which will be described later, by a plain flow.

  FIG. 5 shows the configuration of the control system of each major part in and around the resist coating unit (CT) 82. The control unit 160 includes a microcomputer including a CPU, a memory, and the like, and controls each unit according to predetermined software or a program. The control unit 160 is connected to the substrate upper surface cleaner 126, the substrate lower surface cleaner 128, the coating processing unit 136, the stage cleaner 138, the coating film inspection unit 140, and the nozzle refresh unit 142 through a control system interface and a stage mechanism. 166, the nozzle failure monitor 168, and the like are also connected through a control system interface. The control unit 160 is also connected to a keyboard of an operation panel, a display device (not shown), an external host computer or a controller (not shown), and the like.

  FIG. 6 shows the configuration of the substrate upper surface cleaner 126 and the substrate lower surface cleaner 128 according to one embodiment. The substrate upper surface cleaner 126 has a long cleaner body 170 that extends in the Y direction (horizontal direction orthogonal to the conveyance direction) with a length that can cover the substrate G on the roller conveyance path 120 from one end to the other end. A slit-like suction port 172 extending in the longitudinal direction (Y direction) and a gas ejection port 174 for ejecting gas (for example, clean air) from both sides of the suction port 172 are provided on the lower surface of the cleaner body 170. An intake pipe 176 and a gas supply pipe 178 are connected to the upper and side surfaces of the cleaner body 170, respectively. Inside the cleaner body 170, an air passage or intake passage 180 that connects the suction port 172 and the intake pipe 176 is provided in the center, and a gas supply pipe 178 and a gas outlet 174 are provided on both sides of the intake passage 180. A ventilation path or an air supply path 182 is provided. In the middle of the air supply path 182, a perforated plate 184 is provided for equalizing the jet pressure at the gas jet port 174. The intake passage 180 may also be provided with a perforated plate (not shown) for making the suction force at the suction port 172 uniform. The intake pipe 176 is connected to a vacuum device such as a vacuum pump or an ejector (not shown) through a dust collecting filter (not shown), and the gas supply pipe 178 is connected to a gas supply source such as a compressor (not shown). ing.

The substrate G that has undergone the required heat treatment in the first thermal processing section 26 is carried from the pass unit (PASS _R ) 60 in the oven tower (TB) 48 to the carry-in unit (IN) 81 of the resist coating unit (CT) 82. In doing so, the substrate G passes on the roller transport path 120 just below the substrate upper surface cleaner 126 with an approach distance of, for example, several mm or less. At this time, if foreign matter P such as particles, dust, and debris adheres to the upper surface of the substrate G, the foreign matter P is attracted to the suction port 172 by the vacuum suction force applied to the upper surface of the substrate from the suction port 172 of the cleaner body 170. The air is sucked in and passed through the intake passage 180 and the intake pipe 176 and is captured by the dust collecting filter. Since the gas ejected from the gas ejection port 174 around the suction port 172 hits the upper surface of the substrate and is sucked into the suction port 172, an air curtain is formed. For this reason, there is no possibility of entraining ambient air and attracting dust in the atmosphere. Thus, when the substrate G is carried into the carry-in unit (IN) 81 in a flat flow on the roller conveyance path 120, most of the foreign matter P is removed from the upper surface of the substrate G by vacuum suction cleaning in the substrate upper surface cleaner 126. The

  The substrate lower surface cleaner 128 has the same configuration as the substrate upper surface cleaner 126, and is disposed below the roller conveyance path 120 in the reverse direction (upward) as shown in FIG. Therefore, when the substrate G is carried into the carry-in unit (IN) 81 in a flat flow on the roller conveyance path 120, the substrate lower surface cleaner 128 is the same vacuum suction type as the substrate upper surface cleaner 126 with respect to the lower surface of the substrate G. By performing the cleaning, most of the foreign matter P is removed from the lower surface of the substrate G. Each roller 118 constituting the roller conveyance path 120 is formed by fixing a pair of conveyance rollers 118b to both ends of the shaft 118a, and the substrate G is conveyed on the pair of left and right conveyance rollers 118. Therefore, there is a certain gap between the lower surface of the substrate G and the shaft 118a, and the foreign matter P adhering to the lower surface of the substrate G passes through the gap but is captured by the substrate lower surface cleaner 128. Further, in the configuration in which the substrate upper surface cleaner 126 and the substrate lower surface cleaner 128 are arranged vertically opposite to each other as in this embodiment, the horizontal posture of the substrate G is made by canceling the pressure applied to the substrate G from both cleaners. It can be kept stable.

  FIG. 7 shows the configuration of the stage 132 and the stage cleaner 138 according to one embodiment. The stage 132 is configured as a rectangular parallelepiped mounting table corresponding to the shape and size of the substrate G. On the upper surface of the stage 132, a plurality of holes 190 for accommodating lift pins (not shown) that can be projected and retracted in the vertical direction and a number of vacuum suction ports 192 for fixing the substrate G on the stage are arranged appropriately. It is provided in a pattern.

  When loading the substrate G onto the stage 132, the lift pins protrude vertically upward from the holes 190 to receive the substrate G from the transfer arms 116 and 116 (FIG. 4) at a predetermined height, and then the tip of the pin is the hole 190. The substrate G is lowered to a height position that enters the substrate, and the substrate G is transferred or placed on the stage 132. Each vacuum suction port 192 is connected to a vacuum source (not shown) such as a vacuum pump, and holds the substrate G placed on the stage 132 at a certain height position by a vacuum suction force. When unloading the substrate G from the stage 132, after releasing the vacuum suction force, lift pins project vertically upward from the holes 190 to lift the substrate G to a predetermined height position and pass it to the transfer arms 116 and 116. . Such a loading / unloading mechanism using lift pins and a substrate holding mechanism using a vacuum suction port 192 operate under the control of the control unit 160 as a part of the stage mechanism 166 (FIG. 5).

  In FIG. 7, the stage cleaner 138 is a long cleaner body 194 extending in the Y direction with a length capable of covering the stage 132 from one end to the other end, and horizontally moving the cleaner body 194 in the X direction above the stage 132. That is, it has a scanning unit 196 for scanning. The cleaner body 194 may have the same structure as the substrate upper surface cleaner 126, for example. The cleaner body 194 is connected to a vacuum source (not shown) via the intake pipe 198 and is connected to a gas supply source (see FIG. (Not shown), and has a slit-like air inlet and a gas outlet facing the stage 132. The scanning unit 196 includes an inverted U-shaped support body 202 that horizontally supports the cleaner body 194, and a scanning drive unit 204 that linearly moves the support body 202 in both directions in the X direction. The scanning drive unit 204 may be configured by a ball screw mechanism with a guide or a linear motor mechanism, for example. It is preferable to provide a lifting mechanism 206 with a guide for changing or adjusting the height position of the cleaner body 194 at the joint portion connecting the support body 202 and the cleaner body 194.

  The stage cleaner 138 operates under the control of the control unit 160 while the substrate G is not placed on the stage 132. More specifically, while the cleaner body 194 is scanned at a constant speed by the scanning unit 196 so as to cut vertically above the stage 132 in the X direction, the cleaner body 194 applies a vacuum suction force to each part on the upper surface of the stage 132. By applying, the upper surface of the stage 132 is cleaned so as to sweep from one end to the other end. As a result, the foreign matter adhering or remaining on the stage 132 is captured by the cleaner body 194 and removed.

  FIG. 8 shows the configuration of the coating processing unit 136 and the nozzle failure monitor 168 according to an embodiment. The coating processing unit 136 includes a resist solution supply unit 210 including a resist nozzle 134, a scanning unit 212 that horizontally moves or scans the resist nozzle 134 in the X direction above the stage 132, and changes the height position of the resist nozzle 134. Or it has the nozzle raising / lowering mechanism 220 for adjusting.

  In the resist solution supply unit 210, the resist nozzle 134 has a slit-like discharge port 134a extending in the Y direction with a length that can cover the substrate G on the stage 132 from one end to the other end. (Not shown) is connected to a resist solution supply pipe 214. The scanning unit 212 includes an inverted U-shaped support body 216 that horizontally supports the resist nozzle 134, and a scan drive unit 218 that moves the support body 216 straight in both directions in the X direction. The scanning drive unit 218 can use a ball screw mechanism, but is preferably composed of a linear servo motor mechanism with little mechanical vibration from the viewpoint of the uniformity of the coating film. The nozzle raising / lowering mechanism 220 may be configured by a ball screw mechanism, and adjusts the height position of the resist nozzle 134 between the discharge port 134a at the lower end of the nozzle and the upper surface (surface to be processed) of the substrate G on the stage 132. In addition to arbitrarily setting or adjusting the distance interval, that is, the size of the gap g (FIG. 9), the resist nozzle 134 can be instantaneously moved up and down.

  The coating processing unit 136 operates under the control of the control unit 160 while the substrate G is placed on the stage 132. More specifically, the resist nozzle 134 is scanned at a constant speed by the scanning unit 212 so that the upper part of the stage 132 is vertically cut in the X direction, while the resist solution supply unit 210 performs the stage from the slit-like discharge port 134a of the resist nozzle 134. The resist solution is supplied in a line-like discharge flow extending in the Y direction with respect to the upper surface of the substrate G on 132. At that time, the resist solution overflowing from the discharge port on the substrate G is extended flat at the lower end portion of the resist nozzle 134 that moves forward or horizontally in a predetermined direction in the X direction, and is fixed on the substrate G according to the gap g. A resist solution coating film CR is formed with a film thickness (FIG. 9).

  The nozzle failure monitor 168 inspects whether or not there is a failure in front of the resist nozzle 134 when the above-described resist coating process is performed in the coating processing unit 136. As described above, when the substrate G is carried into the carry-in unit (IN) 81 by the flat-rolling roller conveyance, the upper surface and the lower surface of the substrate G are cleaned by the vacuum suction method by the substrate upper surface cleaner 126 and the substrate lower surface cleaner 128, respectively. In addition, since the upper surface of the stage 132 is also periodically cleaned by the vacuum cleaner by the stage cleaner 138, foreign matter may adhere to the upper surface of the substrate G placed on the stage 132, or the substrate G and the stage The occurrence frequency when a foreign object is sandwiched between the first and second devices is much lower than that in the conventional apparatus. However, there is a possibility that foreign matter may adhere to the upper surface or the lower surface of the substrate G during the transfer from the carry-in unit (IN) 81 to the stage 132, or new foreign matter may adhere to the stage 132. Further, there is a possibility that the foreign substances cannot be completely removed even by the cleaners 126, 128, and 138. In this embodiment, the nozzle failure monitor 168 is provided as a risk hedge, and a substantial foreign matter (which hinders the coating process) adheres to the upper or lower surface of the substrate G placed on the stage 132. In the case of pinching, the contact or sliding contact between the resist nozzle 134 and the substrate G is prevented beforehand by the action of the nozzle failure monitor 168 as described below.

  In FIG. 8, a nozzle failure monitor 168 is a light beam having a high directivity such as a laser beam so as to cross the vicinity of the upper surface of the substrate G placed on the stage 132 substantially horizontally in the Y direction at a predetermined height position. It has a laser emitting part 222 that emits LB, and a light receiving part 224 that is arranged at a position facing the laser emitting part 222 in the Y direction across the substrate G on the stage 132. As shown in the figure, the laser emitting unit 222 and the light receiving unit 224 are respectively attached to a pair of horizontal support arms 226 and 226 protruding forward from the left and right side surfaces of the support 216 in the scanning direction, and from the resist nozzle 134 in the scanning direction. In addition, the laser beam LB is transmitted and received at a position ahead by a certain distance (for example, 100 mm to 200 mm). When the light receiving unit 224 receives the laser beam LB from the laser emitting unit 222, the light receiving unit 224 outputs a voltage signal of a level corresponding to the light amount or light intensity of the received laser beam LB. The nozzle failure monitor 168 has a signal processing circuit, receives the voltage signal from the light receiving unit 224, compares the voltage signal level with a predetermined reference value, and performs monitor determination. Here, the reference value is a voltage signal output from the light receiving unit 224 when the laser beam LB emitted from the laser emitting unit 222 propagates through the air without reaching any obstacle and reaches the light receiving unit 224. It may be a level.

  When the resist coating process is performed in the coating processing unit 136, the obstacle detection laser beam LB of the nozzle fault monitor 168 is also moved above the substrate G along with the resist nozzle 134 by the scanning drive of the scanning unit 212. Scan in the direction. In the scanning with the laser beam LB, at the scanning position where the upper surface of the substrate G is held at the set height position and no foreign matter is attached thereto, as shown in FIG. The laser beam LB from the unit 222 propagates in the vicinity of the upper surface of the substrate without any obstacle and reaches the light receiving unit 224, and a voltage signal having a level approximate to the reference value is obtained from the light receiving unit 224. Therefore, the signal processing circuit of the nozzle failure monitor 168 outputs a monitor determination result indicating that the scanning position is “normal”, that is, there is no obstacle to the resist nozzle 134. As long as the “normal” monitor determination result is output from the nozzle failure monitor 168 in this way, the control unit 160 causes the coating processing unit 136 to continue or continue the resist coating process.

  However, for example, as shown in FIG. 9B, when the foreign substance P is sandwiched between the substrate G and the stage 132 and the substrate G is raised in the vicinity thereof, the laser beam LB is emitted from the substrate during the scanning process. When it reaches the position where G is raised, the laser beam LB is partially blocked by the side surface of the substrate G facing the laser emitting portion 222, and the degree of this light shielding is the degree of the rising of the substrate G. It becomes gradually larger depending on Then, in the light receiving unit 224, the amount of light received by the laser beam LB gradually decreases, and the level of the output signal gradually decreases. The signal processing circuit of the nozzle failure monitor 168 is “abnormal” when the level of the voltage signal from the light receiving unit 224 falls below a predetermined ratio (for example, 50%) with respect to the reference value, that is, at the scanning position. A monitor determination result indicating that some obstacle to the resist nozzle 134 exists is output.

  Alternatively, as shown in FIG. 9C, even when a foreign matter P having a considerable size adheres somewhere on the upper surface of the substrate G, the laser beam LB is blocked by the foreign matter P in the scanning process. At this time, the “abnormal” monitor determination result is output from the signal processing circuit of the nozzle failure monitor 168 in the same manner as described above.

  As shown in FIG. 9, the height position and size (beam diameter d) of the laser beam LB are the lower end of the resist nozzle 134, that is, the upper surface of the substrate G that is normally placed on the ejection port 134a and the stage 132. May be set according to the height position and size (distance interval) of the gap g formed between them, and preferably the height position and size of both (LB, g) may be matched or approximated. For example, when the gap g is set to 100 μm, the beam diameter d of the laser beam LB may be set to 100 μm, and the center height position of the laser beam LB may be matched with the center height position of the gap g.

  When the “abnormal” monitor determination result is output from the nozzle failure monitor 168 as described above, the control unit 160 instructs the coating processing unit 136 to interrupt the resist coating processing.

  At that time, as a first application processing interruption method, the control unit 160 instructs the application processing unit 136 to interrupt scanning. Then, the coating processing unit 136 stops supplying the resist solution from the resist solution supply source to the resist nozzle 134 in the resist solution supply unit 210 and interrupts the resist solution discharge operation of the nozzle 134, and scan driving in the scanning unit 212. The forward drive operation of the part 218 is stopped and the scanning of the registration nozzle 134 is interrupted, and then the backward drive operation is performed by the scanning drive part 218 so that the registration nozzle 134 is retracted or retracted from the upper side of the stage 132 to the home position.

  Alternatively, as a second application processing interruption method, the control unit 160 instructs the application processing unit 136 to move the resist nozzle 134 upward. Then, the coating processing unit 136 instantaneously moves the resist nozzle 134 up in the nozzle lifting mechanism 220. In this case, it is of course preferable that the resist solution supply unit 210 interrupts the resist solution discharge operation. Further, in the scanning drive unit 218, the forward drive operation may be stopped, but may not be stopped. Even if the forward drive operation is not stopped, the resist nozzle 134 moves up instantaneously, and therefore, as shown in FIG. 10 and FIG. (Jump over). As described above, the gap g between the nozzle discharge port and the upper surface of the substrate is about 100 μm, and the height of the obstacle is usually about several hundred μm or less. During the horizontal movement distance (for example, 100 mm to 200 mm) from when the nozzle failure monitor 168 finds an obstacle in front of the resist nozzle 134 until the resist nozzle 134 reaches the position of the obstacle, the resist nozzle 134 is several millimeters. If it rises, it can evacuate upward with a sufficient margin.

  This second coating process interruption method is particularly advantageous when a linear servo motor is used for the scanning drive unit 218. That is, the linear servo motor has little mechanical vibration, but does not have a speed reduction mechanism, and therefore has a long movement distance until it stops completely when emergency braking or stopping is performed. However, in the case of an emergency operation that only raises the registration nozzle 134 by several mm as in this second method, the load inertia moment viewed from the drive unit (electric motor) of the lifting mechanism is low, and the registration nozzle 134 is quickly It is possible to retreat upward and move over the obstacle.

  When the resist coating process is interrupted by the coating processing unit 136 as described above, the substrate G may be recognized as a defective product and then flowed to a subsequent processing step, or a buffer provided at an appropriate place in the system. You may store temporarily in a room or a storage room. In this scene, the stage cleaner 138 may be temporarily operated to clean the upper surface of the stage 132.

  As described above, in this embodiment, in the resist coating process, when there is an obstacle ahead of the resist nozzle 134 in the scanning direction, the foreign matter P is typically present between the substrate G and the stage 132 as described above. When the substrate G is swelled in the vicinity, or when foreign matter P is attached to the upper surface of the substrate G, the nozzle failure monitor 168 detects such an obstacle (swelled portion of the substrate, foreign matter, etc.). Since the nozzle scanning was interrupted at that point in time, the resist nozzle 134 may come into contact with or slide on the raised portion of the substrate G, or the upper surface of the substrate G may be rubbed through foreign matter. It can be prevented in advance.

  Moreover, in the nozzle failure monitor 168 of this embodiment, the obstacle detection laser beam LB propagating or traversing in one direction (Y direction) near the upper side of the substrate G is horizontally moved in the direction (X direction) perpendicular to the propagation direction. Therefore, it is possible to scan the entire upper surface of the substrate uniformly, and it is possible to reliably detect an abnormal location (obstacle) at any location on the substrate G. Further, since the scanning unit 212 in the coating processing unit 136 is used to scan the obstacle detection laser beam LB together with the resist nozzle 134, the monitor mechanism can be simplified and the cost can be reduced.

  12 and 13 show the configuration of the coating film inspection unit 140 according to one embodiment. The coating film inspection unit 140 has an imaging unit 230 that images the upper surface of the substrate G after being subjected to the resist coating process by the coating processing unit 136 as described above, and an image based on an image signal obtained by the imaging unit 230. And a monitor processing unit 232 that determines whether or not the coating film CR on the substrate G has spots (unevenness) by the recognition technique.

  The imaging unit 230 can scan the lamp 236, the condenser lens 238, and the CCD camera 240 in the X direction above the stage 132 (FIG. 4) by the scanning drive of the scanning drive unit 234 (FIG. 4). As shown in FIG. 13, a tubular lamp 236 extending in the Y direction illuminates the upper surface of the substrate G on the stage 132, and the CCD camera 240 images the irradiated portion on the upper surface of the substrate via the condenser lens 238. Yes.

  In FIG. 12, a monitor processing unit 232 converts an analog image signal output from the CCD camera 240 into a digital image signal by an A / D converter 242, and based on the digital image signal, an image recognition unit 244, an image Image processing or determination processing for coating film monitoring, which will be described later, is performed by the memory 246, the monitor determination unit 248, the setting unit 250, the monitor output unit 252, and the like.

  The image recognition unit 244 receives a digital image signal from the A / D converter 242, and uses the image memory 246 to synthesize the images taken by the imaging unit 230, that is, the entire image of one frame, that is, the substrate G. Assemble an image that shows most of the top surface. Then, for example, if a substantial spot is present in the photographed image by known image recognition processing such as binarization, noise removal, labeling, and connected figure analysis, the spot is recognized as a pattern. Here, minute spots that do not substantially degrade the quality of the resist coating film may be excluded from recognition targets. Next, for the pattern-recognized plaque, its shape, size, position, etc. are digitized as indexing attribute data. In general, this type of spot occurs due to the resist nozzle 134 side, that is, when dust or the like adheres to a part of the slit-like discharge port of the resist nozzle 134 or the resist is solidified and clogged. As shown in FIG. 13, streaks (straight lines) M extending linearly in the scanning direction appear at positions on the substrate corresponding to such clogged portions.

  When the monitor determination unit 248 receives the spot attribute data as the recognition result from the image recognition unit 244, the monitor determination unit 248 compares it with the monitoring value set by the setting unit 250 and compares it in terms of shape, size, number, position, and the like. If there are spots that exceed the monitored value, it is determined that the resist coating film on the substrate G is “spotted”. The determination result in the monitor determination unit 248 is sent from the monitor output unit 252 to the control unit 160.

  When the control unit 160 receives the determination result “existence of spots” from the coating film inspection unit 140, the control unit 160 may recognize the substrate G as a defective product and flow it to a subsequent processing step, or You may store temporarily in the buffer room or storage room provided in the right place. Further, when such a defect (spots) in the resist coating film occurs, the resist nozzle 134 is almost always clogged as described above. The nozzle refresh unit 142 is activated to restore the resist solution discharge function.

  FIG. 14 shows the configuration of the nozzle refresh unit 142 according to one embodiment. This nozzle refresh unit 142 may be installed at the home position of the resist nozzle 134, for example, and has a long vertical processing chamber 254 provided with an opening for taking in and out the resist nozzle 134 on the upper surface. In the processing chamber 254, a cleaning nozzle 256 for spraying a cleaning liquid (for example, thinner) toward the vicinity of the discharge port of the resist nozzle 134 housed at a predetermined position in the chamber is disposed. The cleaning nozzle 256 moves horizontally in the longitudinal direction of the nozzle (Y direction) by the scanning drive of the cleaning nozzle scanning mechanism 262 via the vertical support member 258 and the horizontal support member 260, and in the same direction, the entire discharge portion ( Wash the vicinity of the discharge port by applying a cleaning liquid to the other end. The used cleaning liquid is sent to a waste liquid part (not shown) from a drain port 255 provided at the bottom of the processing chamber 254. By this nozzle cleaning, dust, solid resist, and the like attached to the discharge portion of the resist nozzle 134 are washed away. The cleaning liquid supply line includes a cleaning liquid supply pipe 264 from a cleaning liquid supply source (not shown). For example, the vertical support member 258 is formed of a cylindrical body and is connected to the cleaning nozzle 256 through the cleaning liquid supply pipe 264 therein. You can do it. An on-off valve 266 for controlling on / off of the nozzle cleaning may be provided in the middle of the cleaning liquid supply pipe 264. The cleaning nozzle scanning mechanism 262 can be constituted by, for example, a ball screw mechanism with a guide.

  Further, the nozzle refresh unit 142 can perform a dummy dispense that causes the resist nozzle 134 to discharge the resist solution. In this case, the switching valve 268 provided in the resist solution supply pipe 214 is switched to the resist solution supply source side, and the on-off valve 270 is turned on (opened) for a predetermined time. By this dummy dispensing, clogging in the resist nozzle 134 can be removed with a certain probability.

  In this embodiment, in order to more effectively or completely eliminate clogging in the resist nozzle 134, the resist flow path in the nozzle 134 can be replaced with a solvent (for example, thinner) to clean the inside of the nozzle 134. . That is, by switching the switching valve 268 to the solvent supply source side and turning on / off the on-off valve 270 for a certain period of time, the solvent from the solvent supply source is introduced into the resist nozzle 134 via the resist solution supply pipe 214, The solid resist content in the nozzle 134 that causes clogging can be melted and discharged from the discharge port.

  FIG. 15 shows another example of the stage mechanism 166 applicable to the resist coating unit (CT) 82 of the above-described embodiment. In this embodiment, a substrate floating mechanism for horizontally floating the substrate G at a certain height position is provided on a stage 132 for placing the substrate G thereon. More specifically, an arrangement pattern in which a large number of gas ejection holes 254 and a large number of suction holes 256 are mixed at a constant density is provided on the upper surface of the stage 132. Each gas ejection hole 254 communicates with a high-pressure gas supply source 262 through a ventilation path 258 formed inside the stage 132 and a gas pipe 260 drawn outside the stage 132. On the other hand, each suction hole 256 communicates with the vacuum source 268 via a ventilation path 264 formed inside the stage 132 and a gas pipe 266 drawn outside the stage 132. The high pressure gas supply source 262 and the vacuum source 268 operate under the control of the levitation control unit 270.

  In this substrate levitation mechanism, a high-pressure gas is ejected vertically upward from each gas ejection hole 254 on the upper surface of the stage, and the pressure of the high-pressure gas that overcomes the gravity of the substrate G is uniformly applied to the entire lower surface of the substrate G. Float horizontally from the top. Further, each suction hole 256 on the upper surface of the stage is balanced with the pressure of the gas ejected from the gas ejection hole so that the floating position of the substrate G is maintained at a certain height position separated by a certain gap S from the upper surface of the stage. Further, a downward suction force is applied to the substrate G. It is also possible to perform feedback control using a gap sensor (not shown) for detecting the size of the gap S or a height detection sensor (not shown) for detecting the height position of the substrate G. Note that when the substrate G is placed on the stage 132, the operation of the high-pressure gas supply source 262 and the vacuum source 268 is stopped.

  According to this embodiment, since the resist coating process is performed with the substrate G floating from the stage 132, even if foreign matter is attached to the lower surface of the substrate G or the upper surface of the stage 132, the substrate G is raised by the foreign matter. In other words, the contact between the resist nozzle 134 and the substrate G due to the foreign matter under the substrate can be avoided. Even if foreign matter adheres to the upper surface of the substrate G and the resist nozzle 134 contacts the substrate G through the foreign matter, the substrate G in a floating state is lowered by the pressing force from the resist nozzle 134 side. Therefore, the damage caused by contact can be minimized.

  In the above-described embodiment, in one coating process unit 28, the substrate upper surface cleaner 126, the substrate lower surface cleaner 128, the coating processing unit 136, the stage cleaner 138, the coating film inspection unit 140, the nozzle refresh unit 142, the stage mechanism 166, and nozzle failure The elemental technologies of the respective parts such as the monitor 168 are applied in combination or in combination, and their superposed or synergistic effects can be obtained. However, it is also possible to obtain individual functions and effects by applying the elemental technology of each part individually or individually to the coating process section 28.

  In the above embodiment, the substrate upper surface cleaner 126 is disposed above the roller transport path 120, but the upper surface of the substrate G is cleaned in front of the resist nozzle 134 by being attached to the support 216 of the scanning unit 212 in the coating processing unit 136. It is also possible to configure. Alternatively, the stage cleaner 138 can also be used as the substrate upper surface cleaner 126.

  In the above embodiment, the laser emitting unit 222 and the light receiving unit 224 in the nozzle failure monitor 168 are attached to the support 216 of the scanning unit 212 in the coating processing unit 136 so as to scan the substrate simultaneously with the resist nozzle 134. . However, the nozzle failure monitor 168 is configured independently from the coating processing unit 136, and the nozzle failure monitor 168 is operated before starting the resist coating processing, and the obstacle scanning laser beam LB as described above is performed by an individual scanning unit. You may make it perform the scanning of. In this case, when a monitor determination result of “abnormal” is issued from the nozzle failure monitor 168, the coating processing unit 136 may stop the resist coating process on the substrate G.

  In the above-described embodiment, the stage 132 on which the substrate G is placed is fixedly arranged, and the components to be moved or scanned with respect to the substrate G on the stage 132, for example, the resist nozzle 134, the laser emission unit of the nozzle failure monitor 168 222 and the light receiving unit 224 or the stage cleaner 138 are configured to move in a predetermined direction by the scanning drive unit. However, in a reverse relationship, these scanning components may be fixedly arranged and the stage 132 side may be moved in a predetermined direction by the scanning drive unit.

  In the above-described embodiment, the coating film inspection unit 140 is provided in the resist coating unit (CT) 82, but it can also be provided in a subsequent stage, for example, a reduced-pressure drying unit (VD) 84. In the coating film inspection after drying under reduced pressure, the reduced-pressure drying treatment for the defective coating film with spots is wasted, but the image on the coating film becomes clearer after drying than before drying. It has the advantage of being easy to detect.

  As the resist nozzle in the present invention, a slit type nozzle having a slit-like discharge port is used in the above-described embodiment, but a fine diameter type nozzle having one or a plurality of fine diameter discharge holes can also be used. is there.

  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 application that supplies a coating liquid onto a substrate to be processed. As the coating solution in the present invention, in addition to the resist solution, liquids such as an interlayer insulating material, a dielectric material, and a wiring material can 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 side view which shows the structure of the thermal process part in the application | coating development processing system of embodiment. It is a flowchart which shows the procedure of the process in the coating and developing treatment system of embodiment. It is a top view which shows the structure of the application | coating process part in the application | coating development processing system of embodiment. It is a block diagram which shows the structure of the control system of each part in the application | coating process part of embodiment. It is a partial cross section side view which shows the structure of the board | substrate upper surface cleaner and lower surface board | substrate cleaner by one Example. It is a perspective view which shows the structure of the stage mechanism by one Example, and a stage cleaner. It is a perspective view which shows the structure of the application | coating process part and nozzle failure monitor by one Example. It is a partial cross section side view which shows the effect | action of the nozzle failure monitor by an Example. It is a partial cross section side view which shows an example of the obstacle jump operation | movement (nozzle retraction operation | movement) by an Example. It is a partial cross section side view which shows an example of the obstacle jump operation | movement (nozzle retraction operation | movement) by an Example. It is a block diagram which shows the structure of the coating film test | inspection part by one Example. It is a perspective view which shows the structure of the imaging part in the coating film test | inspection part of an Example. It is a figure which shows the structure of the nozzle refresh part by one Example. It is a partial cross section side view which shows the structure of the stage mechanism by another Example.

Explanation of symbols

10 Process Station 28 Application Process Department 81 Carry-in Unit (IN)
82 resist coating unit (CT)
120 Roller transfer path 126 Substrate upper surface cleaner 128 Substrate upper surface cleaner
132 stage 134 resist nozzle 136 coating processing unit 138 stage cleaner 140 coating film inspection unit 142 nozzle refresh unit 166 stage mechanism 168 nozzle failure monitor 210 resist solution supply unit 212 scanning unit 220 nozzle elevating mechanism 222 laser emitting unit 224 light receiving unit 254 high pressure gas Ejection hole 256 Air intake hole
262 High pressure gas supply source 268 Vacuum source 270 Levitation control unit

Claims (16)

A substrate to be processed is floated horizontally at a first height position by applying a gas pressure from below , and the substrate is discharged in a horizontal direction between the nozzle for discharging the coating liquid from a position close to the substrate and the substrate. A coating method for applying the coating liquid on the upper surface of the substrate by performing a coating scan by relative movement of the substrate,
Prior to the application scanning, a second height position corresponding to a height position of a gap formed between the nozzle and the substrate near the upper surface of the substrate floating at the first height position. A light beam with a high directivity having a beam diameter corresponding to the size of the gap so as to cross horizontally at
The light beam is received by a light receiving unit disposed at a position facing the light beam emitting unit across the substrate, and converted into a voltage signal of a level according to the light intensity ,
Moving the light beam emitting part and the light receiving part together with the nozzle relative to the substrate in front of the nozzle in the direction of the application scanning;
The level of the voltage signal output from the light receiving unit is compared with a predetermined reference value, and based on the comparison result, the presence or absence of a substantial obstacle at the second height position is determined,
An application method that selects execution, suspension, or interruption of the application scan for the substrate according to the determination result. The coating method according to claim 1, wherein the second height position matches or approximates a center height position of the gap . The coating method according to claim 1, wherein a beam diameter of the light beam matches or approximates a size of the gap . When the level of the voltage signal falls below a predetermined ratio with respect to the reference value, a determination result that there is a substantial obstacle ahead of the nozzle in the application scan is issued , and the application scan is interrupted. The coating method according to any one of claims 1 to 3 . When the level of the voltage signal falls below a predetermined ratio with respect to the reference value, a determination result is obtained that there is a substantial obstacle ahead of the nozzle in the coating scan, and the nozzle is immediately set to the predetermined value. The coating method according to any one of claims 1 to 3, wherein the coating is moved up to a height position. The high pressure gas is sprayed vertically upward from the gas ejection hole to the lower surface of the substrate, and at the same time, a suction force downward from the suction hole is applied to hold the substrate at the first height position. The coating method as described in any one of 1-5. Determining whether the application liquid exists substantial plaques coating film on the substrate by image recognition by imaging the upper surface of the substrate after being applied, one of the claims 1 to 6 one The coating method according to item. 8. The method according to claim 7 , wherein after the drying process is performed on the coating film on the substrate, the upper surface of the substrate is imaged and whether or not substantial spots are present on the coating film on the substrate is determined by image recognition. Application method. The processing for recovering the coating liquid discharge function of the nozzle to a normal state is performed after the coating scan is completed when a determination result that substantial spots are present in the coating film on the substrate is output. The coating method according to claim 7 or 8 . A levitation support unit that levitates a substrate to be processed from the bottom and horizontally floats at a first height position;
A nozzle for discharging a coating liquid from a position close to an upper side toward the substrate supported at the first height position by the floating support portion;
A coating scanning unit for causing a relative movement in the horizontal direction between the nozzle and the substrate above the substrate ;
In the second height position corresponding to the height position of the gap formed between the nozzle and the substrate near the upper surface of the substrate supported by the floating support portion at the first height position. A light beam emitting unit that emits a highly directional light beam having a beam diameter according to the size of the gap so as to traverse horizontally ;
A light receiving portion that is disposed at a position facing the light beam emitting portion across the substrate, receives the light beam and converts it into a voltage signal of a level according to the light intensity ;
A monitor scanning unit for moving the light beam emitting unit and the light receiving unit together with the nozzle relative to the substrate in front of the nozzle in the coating scanning direction;
A level of the voltage signal output from the light receiving unit is compared with a predetermined reference value, and based on the comparison result, the presence or absence of a substantial obstacle at the second height position is determined . A determination unit;
And a scanning control unit that selects execution, cancellation, or interruption of scanning of the nozzle with respect to the substrate according to a determination result in the first determination unit. 11. The coating apparatus according to claim 10, wherein the light beam emitting unit causes the second height position to coincide with or approximate to a center height position of the gap. The coating apparatus according to claim 10, wherein the light beam emitting unit causes the beam diameter of the light beam to match or approximate the size of the gap. And large number of gas ejection holes for applying pressure vertically upward blown a high pressure gas to the lower surface of the substrate to be processed,
A plurality of gas suction holes that are arranged in an arrangement pattern mixed with the gas ejection holes at a constant density and apply downward pressure by suction to the lower surface of the substrate;
In order to maintain the height position of the substrate at the first height position, the balance between the vertically upward pressure applied to the substrate from the gas ejection holes and the downward pressure applied to the substrate from the gas suction holes A levitation control unit that takes
A nozzle for discharging a coating liquid from a position close to the upper side toward the substrate floating at the first height position;
A coating scanning unit for causing a relative movement in the horizontal direction between the nozzle and the substrate above the substrate;
The upper surface of the substrate floating at the first height position is horizontally traversed at a second height position corresponding to the height position of a gap formed between the nozzle and the substrate. A light beam emitting part for emitting a highly directional light beam having a beam diameter according to the size of the gap;
A light receiving portion that is disposed at a position facing the light beam emitting portion across the substrate, receives the light beam and converts it into a voltage signal of a level according to the light intensity;
A monitor scanning unit for moving the light beam emitting unit and the light receiving unit together with the nozzle relative to the substrate in front of the nozzle in the coating scanning direction;
A level of the voltage signal output from the light receiving unit is compared with a predetermined reference value, and based on the comparison result, the presence or absence of a substantial obstacle at the second height position is determined. A determination unit;
A scanning control unit that selects execution, cancellation, or interruption of scanning of the nozzle with respect to the substrate according to a determination result in the first determination unit;
A coating apparatus. An elevating mechanism for moving the nozzle up and down, and when the determination result that there is a substantial obstacle ahead of the nozzle during the scanning is issued from the determination unit, the elevating mechanism immediately The coating device according to any one of claims 10 to 13 , wherein the nozzle is moved up to a predetermined height position. An imaging unit that images the upper surface of the substrate after the coating liquid is applied;
Claim 10 to 14 and a second determining unit that determines whether a substantial plaque is present in the coating film on the substrate by image recognition based on the image signal obtained by the imaging unit The coating apparatus according to one item. A nozzle refresh unit for applying processing to the nozzle to recover the coating liquid discharge function of the nozzle to a normal state;
The coating apparatus according to claim 15 , further comprising: a refresh control unit that causes the nozzle refresh unit to perform the recovery process when a determination result indicating that substantial unevenness exists on the upper surface of the substrate is issued in the determination unit.

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