JP4813583B2 - Substrate processing equipment - Google Patents

Description

  The present invention relates to a substrate processing apparatus that heats a substrate to be processed in a photolithography process, and more particularly to a flat-flow type substrate processing apparatus.

  In the manufacture of semiconductor devices and flat panel displays (FPDs), many of the components on the substrate to be processed are created using photolithography. Generally, the photolithography process has three basic steps: a coating process for applying a resist on a substrate, an exposure process for transferring a photomask pattern to a resist film, and a developing process for developing a latent image pattern of the resist film. In addition, various heat treatments are performed as auxiliary steps before, after, or between these basic steps. For example, a heat treatment (pre-bake) for evaporating the residual solvent in the resist film is performed between the coating process and the exposure process. After the development step, heat treatment (post-bake) is performed to evaporate and remove the developer and cleaning solution remaining in the resist pattern.

  In recent years, in-line systems that consistently carry out all photolithography processes in FPD manufacturing, in order to cope with the increase in substrate size, as with other processing devices incorporated in the system, the pre-baking device and post-baking device are flat. An increasing number of people adopt the sink method (for example, Patent Document 1).

  In general, in a flat-flow type baking apparatus, a conveyance path composed of a conveyance body such as a roller or a roller is laid so as to vertically cross or traverse the inside of the unit, and is carried into the unit from a processing apparatus adjacent to the upstream side. The substrate is heated to a predetermined temperature by a nearby heater while moving in a flat flow on the transfer path, and after passing through the heater, it flows straight out of the unit and is sent to the downstream processing unit (usually a cooling device). It has become.

  Unlike the so-called hot plate oven type baking apparatus, such a flat-flow type baking apparatus does not require a chamber, a hot plate, a lift pin mechanism, a transfer robot, etc., and the apparatus configuration is greatly simplified and reduced in cost. There is an advantage that the throughput can be increased.

JP 2008-159768 A

  However, in the conventional flat-flow type baking apparatus, it is unexpectedly difficult to uniformly heat the substrate moving horizontally on the transfer path in the processing chamber, and in particular, the temperature at the rear end of the substrate is the highest in the flat-flow transfer direction. Thus, the problem is that the temperature at the center of the substrate tends to be the lowest.

  In the horizontal direction (river width direction) orthogonal to the transport direction, by adjusting the heat generation temperature distribution of the heater, for example, a substrate temperature error generated between the substrate peripheral portion and the substrate central portion can be easily corrected. However, since any part of the substrate passes through the same place at the same speed in the transport direction, the error in the substrate temperature cannot be corrected by adjusting the heat generation temperature distribution of the heater.

  For this reason, conventionally, in order to avoid as little as possible the heating of the central part of the substrate in the transport direction, a method of generally increasing the heat generation temperature of the heater, or a heating section (or heating time) on the transport path is lengthened. Although the method is adopted, it is not a fundamental solution due to a decrease in energy efficiency, space efficiency or throughput.

  Further, in this type of conventional baking apparatus, the remaining or excess heat (waste heat) used for heating the substrate is wasted to the outside through the walls of the processing chamber and the exhaust pipe, and is reused. Not used or used effectively.

  The present invention has been made in view of the above-described prior art, and provides a flat-flow-type baking substrate processing apparatus capable of simultaneously improving energy efficiency and substrate temperature characteristics.

  A substrate processing apparatus according to the present invention is a substrate processing apparatus for performing a heat treatment on a substrate to be processed, and is configured to flow an unprocessed substrate into a room in a flat flow and a processed substrate in a flat flow. A processing chamber having an outlet for carrying out the chamber; an exhaust unit for discharging gas generated from the substrate by the heat treatment; and the processing chamber through the inlet and the outlet. A transport path that horizontally traverses or traverses the interior of the chamber, and a transport section that transports the substrate in a flat flow on the transport path, and is disposed along the transport path to heat the substrate on the transport path to a predetermined temperature. A warming air that draws air from outside the processing chamber, transfers heat that is released from the processing chamber to the outside of the processing chamber, generates warm air, and sends the warm air into the processing chamber And a supply unit.

  In the above apparatus configuration, since warm air is sent instead of outside air into the processing chamber where the heat treatment is performed, it is possible to efficiently prevent the influence of the outside air on the flat-flow heat treatment. The temperature uniformity in the conveying direction can be greatly improved. And since warm air is produced | generated using the waste heat inevitably generated by heat processing, it is excellent also in terms of energy efficiency.

  According to the substrate processing apparatus of the present invention, with the above-described configuration and operation, energy efficiency and substrate temperature characteristics (rising characteristics, uniformity, etc.) are simultaneously achieved in a flat-flow-type baking substrate processing apparatus. can do.

It is a top view which shows the layout structure of the coating and developing treatment system which incorporates the substrate processing apparatus of this invention suitably. It is a schematic side view which shows the whole structure of the prebaking unit in one Embodiment of this invention. It is a cross-sectional view which shows one structural example of the heat exchanger provided in the said prebaking unit. It is a perspective view which shows another structural example of the heat exchanger provided in the said prebaking unit. It is a perspective view which shows the modification of the heat exchanger of FIG. It is a perspective view which shows another modification of the heat exchanger of FIG. It is a schematic plan view which shows the other modification of the heat exchanger of FIG. It is a perspective view which shows the structure of the heat exchanger of FIG. 6A. It is a side view which shows one step of the operation | movement in the said prebaking unit. It is a side view which shows one step of the operation | movement in the said prebaking unit. It is a side view which shows one step of the operation | movement in the said prebaking unit. It is a figure for demonstrating the evaluation method of the temperature distribution in the board | substrate which receives the heat processing of a flat flow system. It is a figure which shows the substrate temperature characteristic (change on a time axis | shaft) in the said prebaking unit by one experimental example by contrast with a reference example. It is an approximate side view showing the whole prebaking unit composition by one modification of an embodiment.

  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 substrate processing apparatus of the present invention can be applied. This coating / development processing system 10 is installed in a clean room. For example, a glass substrate is used as a substrate to be processed, and a series of processes such as cleaning, resist coating, pre-baking, developing, and post-baking in a photolithography process are performed in LCD manufacturing. Is what you do. The exposure process is performed by an external exposure apparatus 12 installed adjacent to this system.

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

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

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

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

  More specifically, the carry-in unit (IN PASS) 24 receives the unprocessed substrate G from the transfer mechanism 22 of the cassette station (C / S) 14 and inputs it into the first flat flow transfer path 34 at a predetermined tact. It is configured. The cleaning process section 26 is provided with an excimer UV irradiation unit (E-UV) 36 and a scrubber cleaning unit (SCR) 38 in order from the upstream side along the first flat flow path 34. The first thermal processing unit 28 includes an adhesion unit (AD) 40 and a cooling unit (COL) 42 in order from the upstream side. The coating process unit 30 includes a resist coating unit (COT) 44 and a vacuum drying unit (VD) 45 in order from the upstream side.

  The second thermal processing unit 32 includes a conveyor unit (CONV) 46, a pre-bake unit (PRE-BAKE) 48, and a cooling unit (COL) 50 in order from the upstream side. A pass unit (PASS) 52 is provided at the end point of the first flat flow conveyance path 34 located adjacent to the downstream side of the second thermal processing unit 32. The substrate G that has been transported in a flat flow on the first flat flow transport path 34 is transferred from the pass unit (PASS) 52 at the end point to the interface station (I / F) 18.

  The conveyor unit (CONV) 46 is used to adjust or switch the conveyance speed of the substrate G here, or to retract and retain the nearby substrate G when an abnormal situation occurs somewhere in the system. The

  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 developing unit (DEV) 54, a conveyor unit (CONV) 55, a post bake unit ( (POST-BAKE) 56, cooling unit (COL) 58, inspection unit (AP) 60 and carry-out unit (OUT-PASS) 62 are arranged in a line in this order from the upstream side along the second flat flow path 64. ing. Here, the post-bake unit (POST-BAKE) 56 and the cooling unit (COL) 58 constitute a third thermal processing unit 66. The carry-out unit (OUT PASS) 62 is configured to receive the processed substrates G one by one from the second flat flow transfer path 64 and pass them to the transfer mechanism 22 of the cassette station (C / S) 14. .

  The conveyor unit (CONV) 55 is used here to adjust or switch the conveyance speed of the substrate G, or to retract and retain the nearby substrate G when an abnormal situation occurs somewhere in the system. The

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

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

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

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

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

  In the coating process section 30, the substrate G is first coated with a resist solution on the upper surface (surface to be processed) by a spinless method using a slit nozzle while being flown flat in a resist coating unit (COT) 44, and immediately after that, adjacent to the downstream side. A vacuum drying unit (VD) 45 receives a vacuum drying process.

  The substrate G that has left the coating process unit 30 passes through the second thermal processing unit 32 through the first flat flow path 34. In the second thermal processing section 32, the substrate G passes through the conveyor unit (CONV) 46, and then is pre-baked as a heat treatment after resist coating or pre-exposure heat treatment by a pre-bake unit (PRE-BAKE) 48. receive. By this pre-baking, the solvent remaining in the resist film on the substrate G is evaporated and removed, and the adhesion of the resist film to the substrate is enhanced. Next, the substrate G is cooled to a predetermined substrate temperature by a cooling unit (COL) 50. Thereafter, the substrate G is taken from the pass unit (PASS) 52 at the end point of the first flat flow transport path 34 to the transport device 72 of the interface station (I / F) 18.

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

  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, first, it is carried into a titler (TITLER) of the peripheral device 76, where it is transferred to a predetermined portion on the substrate. Is recorded. Thereafter, the substrate G is carried from the transfer device 72 to the starting point of the developing unit (DEV) 54 of the second flat flow transfer path 64 laid on the process line B side of the process station (P / S) 16. .

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

  The substrate G that has undergone a series of development processes in the development unit (DEV) 54 is placed on the second flat flow path 64 as it is, and is conveyed to the conveyor unit (CONV) 55, the third thermal processing unit 66, and the inspection unit. (AP) 60 is sequentially passed. In the third thermal processing section 66, the substrate G is first subjected to post-baking as a heat treatment after development processing by a post-bake unit (POST-BAKE) 56. By this post-baking, the developing solution and the cleaning solution remaining in the resist film on the substrate G are removed by evaporation, and the adhesion of the resist pattern to the substrate is enhanced. Next, the substrate G is cooled to a predetermined substrate temperature by a cooling unit (COL) 58. In the inspection unit (AP) 60, non-contact line width inspection, film quality / film thickness inspection, and the like are performed on the resist pattern on the substrate G.

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

  In the coating and developing processing system 10, the present invention can be applied to the second thermal processing unit 32, particularly to the pre-bake unit (PRE-BAKE) 48. Hereinafter, the configuration and operation around the pre-bake unit (PRE-BAKE) 48 in the preferred embodiment of the present invention will be described in detail with reference to FIGS.

  FIG. 2 shows the configuration of the second thermal processing unit 32 in this embodiment. The thermal processing section 32 is provided with a flat flow path 34 in the horizontal direction (X direction) parallel to the process line A, and a conveyor unit (CONV) 46 in order from the upstream side along the transfer path 34, A pre-bake unit (PRE-BAKE) 48 and a cooling unit (COL) 50 are installed.

  The transport path 34 is formed by laying rollers 80 for transporting the substrate G in a supine posture at regular intervals in the transport direction (X direction), as an extension from the coating process unit 30 adjacent to the upstream side (FIG. 1). The unit is drawn into the thermal processing unit 32, traverses or crosses the units 46, 48, and 50, and further extends to a downstream pass unit (PASS) 52 (FIG. 1). Each roller 80 of the conveyance path 34 is connected to a conveyance drive unit (not shown) having a motor, for example, via a transmission mechanism such as a gear mechanism or a belt mechanism.

  The conveyor unit (CONV) 46 is partitioned from the outside by partition walls 82 and 84 extending from the upper end to the lower end of the unit in the substrate transport direction (X direction). The partition walls 82 and 84 are respectively formed with transport passages 82a and 84a through which the transport path 34 and the substrate G pass.

  Further, the conveyor unit (CONV) 46 is also partitioned from the outside by side walls (not shown) on both sides in the flat-flowing river width direction (Y direction). A hole (not shown) with a seal member for connecting to the mechanism is provided.

  In the conveyor unit (CONV) 46, a partition plate 86 that is suspended from the ceiling at a certain interval from the upstream partition wall 82 is provided, and a temperature of a hot air supply unit 140 described later is interposed between the partition wall 82 and the partition plate 86. A wind blowing portion 146 is provided. A hot air guide plate 88 is horizontally provided so as to cover the upper and lower sides of the conveyance path 34 from the vicinity of the partition plate 86 to the vicinity of the partition wall 84 on the downstream side.

  The pre-bake unit (PRE-BAKE) 48 is partitioned from the outside by partition walls 84 and 90 extending from the upper end to the lower end of the unit in the substrate transport direction (X direction), and the inside of the partition walls 84 and 90 is a pre-baking processing chamber. (Oven). A transport passage port 84a of the upstream partition wall 84 and a transport passage port 90a formed in the downstream partition wall 90 are an inlet and an outlet of a pre-bake unit (PRE-BAKE) 48, respectively.

  The pre-bake unit (PRE-BAKE) 48 is also partitioned from the outside by side walls (not shown) on both sides in the flat river width direction (Y direction). A hole (not shown) with a seal member for connecting to the mechanism is provided.

  The processing chamber of the pre-bake unit (PRE-BAKE) 48 is divided into three baking chambers 96, 98, 100 by two internal partition walls 92, 94. Among these, the first-stage baking chamber (Pre-Heat) 96 located on the most upstream side in the transport direction is a rapid heating for rapidly raising the temperature of the substrate G from room temperature or preheating temperature to a set temperature suitable for prebaking. A heater 102 is disposed not only below the conveyance path 34 but also above the room.

  The middle baking chamber (Bake 1) 98 and the final baking chamber (Bake 2) 100 are heat insulation heating chambers for maintaining the temperature of the substrate G in the vicinity of the preset temperature for pre-baking. Heaters 104 and 106 are disposed only below.

  The heaters 102, 104, and 106 are planar heaters such as a sheathed heater or a carbon heater that can uniformly heat the substrate G on the transport path 34 in the direction of the flat river width (Y direction), and are independent in each chamber. The pre-baking temperature can be set. As an example, the pre-baking temperature in the first-stage baking chamber (Pre-Heat) 96 is set to 180 ° C., and the pre-baking temperatures in the middle-stage and final-stage baking chambers (Bake 1) 98 and (Bake 2) 100 are 110 ° C. Each is set to 120 ° C.

  Exhaust ports are respectively provided in the bottom walls or side walls of the baking chambers 96, 98, and 100, and these exhaust ports are connected to an exhaust device 114 having, for example, a vacuum pump via exhaust pipes 108, 110, and 112. The vapor of the solvent generated from the substrate G on the transfer path 34 in the baking chambers 96, 98, 100 is discharged outside the chamber through this exhaust system.

  The cooling unit (COL) 50 is partitioned from the outside by partition walls 90 and 116 extending from the upper end to the lower end of the unit in the substrate transport direction (X direction), and further, the inside of the unit is divided into two cooling chambers 120 and 122 by the inner partition wall 118. It is divided into A transport passage port 90a formed in the upstream partition wall 90 and a downstream partition wall 116 are an inlet and an outlet of the cooling unit (COL) 50, respectively.

  The cooling unit (COL) 50 is also partitioned from the outside by side walls (not shown) on both sides in the flat-flowing river width direction (Y direction). On both side walls, the rollers 80 in the unit are used as external transmission mechanisms. A hole (not shown) with a seal member for connection is provided.

  In the first-stage cooling chamber 120, a partition plate 124 that is hung from the ceiling with a certain distance from the upstream partition wall 90 is provided, and an intake nozzle 126 is provided between the partition wall 90 and the partition plate 124. The partition plate 124 is used to block the atmosphere, and forms a substantial inlet of the cooling unit (COL) 50. In the section from the partition plate 124 to the internal partition wall 118 on the downstream side, one or a plurality of cold air nozzles 128 are disposed above the conveyance path 34 to form a rapid cooling zone.

  In the downstream cooling chamber 122 on the downstream side, cooling water having a constant temperature is circulated and supplied from the cooling water supply unit 130 to each roller 80 of the conveyance path 34 to form a water-cooled roller heat transfer cooling zone. The interior of the cooling unit (COL) 50 is also exhausted through the exhaust pipe 132 from the exhaust port on the bottom wall or side wall of the unit. The cooling water supply unit 130 may be provided outside the cooling unit (COL) 50.

  The thermal processing unit 32 in this embodiment includes a hot air supply unit 140 for supplying hot air into the processing chamber of the pre-bake unit (PRE-BAKE) 48.

  The hot air supply unit 140 includes an air supply duct 142 provided on the back of the ceiling over the conveyor unit (CONV) 46 and the first-stage baking chamber (Pre-Heat) 96 of the pre-bake unit (PRE-BAKE) 48, Near the entrance of the heat exchanger 144 and the entrance of the conveyor unit (CONV) 46 installed in the back of the ceiling of the first-stage baking room (Pre-Heat) 96 just inside the inlet (air intake port) 143 of the air supply duct 142 It has an FFU (fan filter unit) 148 disposed at the end of the air supply duct 142 in the hot air ejection part 146 and an air filter 150 disposed in the middle part of the air supply duct 142.

  When the fan of the FFU 148 operates, the inner space of the air supply duct 142 becomes negative pressure, and the outside air is sucked (taken in) into the inlet 143 of the air supply duct 142. The taken-in air is heated there when passing through the heat exchanger 144 and becomes warm air of a predetermined temperature (for example, 50 ° C. to 80 ° C.), and a relatively large foreign matter (dust) or contamination is caused by the air filter 150 on the way. The material (solvent vapor, etc.) is removed and exits from the inlet side to the outlet side of the FFU 148 fan. The FFU 148 filter removes minute particles contained in the hot air. In this way, clean hot air blows down from the ceiling FFU 148 toward the conveyance path 34 directly below the hot air jetting part 146.

  In the hot air supply unit 140, around the heat exchanger 144 (more preferably over the entire length of the air supply duct 142), the upper wall and the side wall of the air supply duct 142 are made of a heat insulating material, and the heat exchanger The structure is such that the heat of 144 is difficult to escape from the air supply duct 142.

  Adjacent to the hot air jetting part 146, on the outside of the partition wall 82, a horizontally or elongate intake nozzle 152 extending in the direction of the flat river width (Y direction) is horizontally disposed with the intake port facing the conveyance path 34. ing. The intake nozzle 152 is connected to an exhaust device 154 having a vacuum pump, for example.

  An intake nozzle 126 disposed outside the partition wall 90 adjacent to the outlet 90a of the pre-bake unit (PRE-BAKE) 48 is also a long type, and is similarly connected to the exhaust device 154. In addition, the intake nozzle 126 not only sucks the cold air that is under the partition plate 124 from the cold air nozzle 128 of the cooling unit (COL) 50, but also leaks from the outlet 90a of the pre-bake unit (PRE-BAKE) 48. Since the baking atmosphere gas containing the solvent sublimate is also sucked, a heater 156 is attached in order to prevent the solvent sublimate from being cooled and condensed (liquefied) by the intake nozzle 126.

  FIG. 3 shows a preferred configuration example of the heat exchanger 144 provided in the hot air supply unit 140. The heat exchanger 144 is made of a material having high thermal conductivity, such as aluminum, and is in close contact with the ceiling wall of the first-stage baking chamber (Pre-Heat) 96 and is thermally coupled. An air passage 144a having a labyrinth structure as shown in FIG. As described above, when the pre-baking temperature in the first-stage baking chamber (Pre-Heat) 96 is about 180 ° C., waste heat of substantially the same temperature is transmitted to the heat exchanger 144 through the ceiling wall, and the heat exchanger 144 It is used for heat exchange with the air passing through. By this heat exchange, the air that has flowed into the air supply duct 142 from the surrounding clean room space changes from the original temperature (room temperature, for example, 23 ° C.) to warm air that is several steps higher (for example, 60 ° C. or more).

  In addition, since the temperature of the warm air generated by the heat exchanger 144 becomes too high and exceeds the heat resistance temperature of the FFU 148 (for example, 80 ° C.), a temperature adjustment mechanism for adjusting the temperature of the warm air to an appropriate temperature ( (Not shown).

  FIG. 4 shows another configuration example of the heat exchanger 144. In this heat exchanger 144, a rectangular tube-shaped heat exchange unit 160 made of a material having high thermal conductivity, for example, aluminum is thermally coupled to the ceiling wall of the first-stage baking chamber (Pre-Heat) 96, and heat exchange is performed. A wire mesh 162 is attached to the opening (air passage) of the unit 160 in order to increase heat exchange efficiency. As shown in the figure, the heat exchange efficiency can be further enhanced by arranging a plurality of heat exchange units 160 in a row in the air supply duct 142.

  In order to further increase the heat exchange rate in the heat exchanger 144 of FIG. 4, as shown in FIG. 5A, the partition plate 164 having the passage 164a in the lower portion and the partition plate 166 having the passage 166a in the upper portion are alternately heated. You may insert between the exchange units 160 and 160. FIG. Alternatively, as shown in FIG. 5B, a partition plate 168 having a passage 168a at the lower portion and a partition plate 170 having a passage 170a at the upper portion may be alternately inserted between the heat exchange units 160 and 160. In addition, although not shown in the drawing, a configuration in which the heat exchange unit 160 is increased in the total length in the air flow direction and only one unit is sufficient.

  Further, as shown in FIGS. 6A and 6B, a heat exchanger 144 may be configured using a pipe (pipe) 145. The pipe 145 is preferably made of an aluminum pipe or a SUS pipe having a high thermal conductivity, and has a serpentine labyrinth structure as shown, for example, and is provided in the back of the ceiling of the baking room and / or in the baking room. When arrange | positioning in a ceiling back, it is preferable to surround the circumference | surroundings (except the ceiling side of a baking room) of the piping 145 with a heat insulating material. In the case of a baking chamber, the pipe 145 can be disposed near the heater 102.

  Room temperature dry air is introduced into the inlet 145a of the pipe 145, or room temperature wind is sent by a fan (not shown) or the like. The outlet 145b of the pipe 145 is connected to the warm air jet nozzle 146N directly or via a filter (not shown) as shown.

  Here, the overall operation of the thermal processing unit 32 will be described.

  As described above, the substrate G is coated with a resist solution in the coating process unit 30 (FIG. 1), and immediately after undergoing a vacuum drying process, the substrate G moves on the transport path 34 by a flat flow of roller transport and is thermally treated. The processing unit 32 is entered.

  In the thermal processing unit 32, when the substrate G first passes through the conveyor unit (CONV) 46, the hot air descending from the hot air blowing unit 146 hits the upper surface of the substrate G, and the upper and lower temperatures are kept together with the substrate G. The passage or the conveyance space on the conveyance path 34 sandwiched between the wind guide plates 88 is moved downstream.

  In front of the inlet 82 a of the conveyor unit (CONV) 46, the intake nozzle 152 sucks a part of the hot air from the hot air blowing section 146 and at the same time, the inlet of the conveyor unit (CONV) 46 from the upstream side of the conveyance path 34. The outside (room temperature) air flowing toward 82a is also sucked in. Thereby, there is little or no outside air (room temperature) entering the conveyor unit (CONV) 46 through the inlet 82a. A similar intake nozzle (not shown) can be provided below the conveyance path 34 so as to face the intake nozzle 152.

  In this way, when the substrate G passes through the conveyor unit (CONV) 46, it is exposed to warm air at a temperature several degrees higher than room temperature (for example, 60 ° C.), so that a considerable amount of solvent is formed from the resist film on the substrate G. However, since it is still much lower than the pre-baking set temperature (110 ° C. or higher), the resist film is still kept dry.

  Thus, the substrate G together with the warm air passes from the conveyor unit (CONV) 46 through the conveyance opening (inlet) 84a of the partition wall 84a to the first-stage baking chamber (Pre-Heat) 96 of the pre-bake unit (PRE-BAKE) 48. enter. In the first-stage baking chamber (Pre-Heat) 96, the substrate G passes through a high-temperature (for example, 180 ° C. to 200 ° C.) atmosphere for rapid heating sandwiched between the upper and lower heaters 102. It rises at a stretch from a preheating temperature (about 60 ° C.) to a predetermined temperature suitable for pre-baking (eg, 110 ° C. to 120 ° C.). Thus, the pre-baking heat treatment is started.

  After passing through the first-stage baking chamber (Pre-Heat) 96, the substrate G sequentially moves in the middle-stage baking chamber (Bake1) 98 and the final-stage baking chamber (Bake2) 100 while moving on the transfer path 34 in a plain flow. A predetermined time (for example, 30 to 40 seconds) is spent in the meantime, and a heat treatment at a set temperature (110 ° C. to 120 ° C.) is continuously received. As a result, most of the residual solvent in the resist evaporates from the substrate G, the resist film becomes thin and hard, and adhesion to the substrate is improved.

  The substrate G that has been subjected to the pre-bake heat treatment as described above in the pre-bake unit (PRE-BAKE) 48 moves on the transport path 34 by roller transport and passes through the cooling unit (COL) 50.

  In the cooling unit (COL) 50, the substrate G passes under the intake nozzle 126 and enters a rapid cooling zone, where cold air having a constant temperature (for example, 20 ° C.) regulated by the cold air nozzle 128 is blown. As a result, the temperature of the substrate G drops from the pre-baking temperature to near room temperature. In the subsequent cooling chamber 122, the substrate G moves in a flat flow on the transport path 34 (roller 80) cooled by the cooling water supply unit 130 to a constant temperature (for example, 23 ° C.) with water cooling. The whole substrate is fully cooled to a predetermined temperature (for example, 23 ° C.).

  The intake nozzle 126 disposed between the pre-bake unit (PRE-BAKE) 48 and the rapid cooling chamber 120 of the cooling unit (COL) 50 has a pre-baking atmosphere leaking from the outlet 90a of the pre-bake unit (PRE-BAKE) 48. At the same time as sucking in gas (or exhaust gas), cool air flowing from the rapid cooling chamber 120 adjacent to the downstream side toward the outlet 90a of the pre-bake unit (PRE-BAKE) 48 is also sucked in. As a result, there is little or no outside air entering the pre-bake unit (PRE-BAKE) 48 through the outlet 90a. A similar intake nozzle (not shown) may be provided below the conveyance path 34 so as to face the intake nozzle 126.

  As described above, in the pre-bake unit (PRE-BAKE) 48 of this embodiment, the airflow entering the processing chamber (oven) from the inlet 84a is warm air, and the outside cold air hardly enters. In this way, although the pre-baking atmosphere gas exits from the processing chamber on the outlet 90a side, outside cold air does not enter the processing chamber. Further, since the pre-baking atmosphere gas leaked outside from the outlet 90a is sucked into the intake nozzle 126, it does not diffuse around.

  Thus, since the outside cold air (outside air) hardly enters the processing chamber (oven) of the pre-baking unit (PRE-BAKE) 48, the flat-flow type heat treatment is not affected by the outside air, and the pre-baking is performed. The substrate temperature characteristics are improved in all respects. In particular, the rising characteristics of the substrate temperature due to rapid heating in the first-stage baking chamber (Pre-Heat) 96 and the uniformity of the substrate heating temperature in the transport direction are greatly improved.

  In this embodiment, it is particularly important that hot air from the hot air blowing portion 146 enters the first-stage baking chamber (Pre-Heat) 96 of the pre-baking unit (PRE-BAKE) 48 instead of outside air from the inlet 84a. is there.

  That is, in the case where the hot air ejection section 146 and the suction nozzle 152 associated therewith are removed from the thermal processing section 32 of this embodiment (reference example), as shown in FIGS. 7A and 7B, the substrate G is used for rapid heating. When the air enters the first-stage baking chamber (Pre-Heat) 96, outside air also flows in with it (using the substrate G as a guide plate). Thereby, when the front end portion or the center portion of the substrate G enters the high temperature atmosphere of the heater 102 in the transport direction, the outside air enters there, so that the high temperature atmosphere is cooled by the influence of the outside air, and the substrate temperature Ascending (rise) speed is reduced. There is a time delay in the influence of such inflow of outside air, and the degree of rapid heating reduction is greater in the central portion of the substrate than in the front end portion of the substrate.

  On the other hand, as shown in FIG. 7C, when the rear end of the substrate G enters the high-temperature atmosphere near the heater 102, there is nothing behind the substrate G that functions as a guide plate, and no outside air enters. Therefore, the degree to which rapid heating is affected by outside air is small.

  As a result, as shown in FIG. 8, the temperature at the rear end of the substrate is highest and the temperature at the center of the substrate is likely to be lowest through the pre-baking process. If the uniformity of the substrate temperature is not good, the uniformity of the physical properties of the resist film is lowered, and the accuracy and reliability of photolithography are impaired.

  In this regard, in the thermal processing section 32 of this embodiment, as shown in FIGS. 7A and 7B, when the substrate G enters the first-stage baking chamber (Pre-Heat) 96 for rapid heating ( Hot air flows in (using the substrate G as a guide plate). Since this warm air is much higher than the outside air (about 23 ° C.) (for example, 60 ° C.), the influence of the high temperature atmosphere of the heater 102 by the inflow of the warm air is very small. Therefore, there is no significant difference in the strength of rapid heating between when the front end or the center of the substrate G enters the high temperature atmosphere and when the rear end enters, as shown in FIG. The temperature uniformity is greatly improved.

Actually, when the present inventor compared the example and the above reference example by experiment, an experimental result (data) as shown in FIG. 9 was obtained. In this experiment, in the example, the temperature of the hot air supplied from the hot air supply unit 140 into the first-stage baking chamber (Pre-Heat) 96 of the pre-bake unit (PRE-BAKE) 48 is 65 ° C. to 70 ° C. and the flow rate is 3 Set to 2 m ³ / min.

  As shown in FIG. 9, an experimental result supporting the above theory was obtained. Looking at the substrate temperature during and immediately after the rapid heating (Pre-Heat), which is particularly important in pre-baking of flat flow (Bake1), the embodiment achieved much higher temperatures than the reference example in all parts of the substrate. ing. In addition, in the uniformity of the substrate temperature in the transport direction, the example is significantly improved over the reference example. For example, the temperature difference between the front end portion and the rear end portion at the end of the rapid heating (Pre-Heat) is about 7.3 ° C. in the reference example, and is about 3.5 ° C. in the embodiment. It is halved.

  In this embodiment, as described above, the warm air supplied into the processing chamber (oven) of the pre-bake unit (PRE-BAKE) 48 is heated by the warm air supply unit 140 to the outside room temperature air and the processing chamber (oven). The point generated from the waste heat is also very important.

  That is, the flow rate of warm air introduced into the processing chamber (oven) from the inlet 84a of the pre-bake unit (PRE-BAKE) 48 is the flow rate of exhaust gas discharged from the exhaust system (108 to 114) of the processing chamber (oven). Is equivalent to the sum of the flow rate of the atmospheric gas leaking out from the outlet 90a and is not a small amount. Therefore, if a heater is used as the hot air generating means in the hot air supply unit 140, a large amount of electric power is consumed.

  However, since the warm air supply unit 140 in this embodiment generates warm air using waste heat inevitably generated in the pre-bake unit (PRE-BAKE) 48, it consumes electric power in addition to driving the FFU 148 fan. There is nothing and running costs are very low.

[Other Embodiments and Modifications]
Although a preferred embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and other embodiments or various modifications are possible within the scope of the technical idea.

  For example, the hot air supply unit 140 may have a configuration as shown in FIG. The hot air supply unit 140 of this configuration example is provided with a plurality of air supply ducts 172, 174, and 176 (three systems in the illustrated example).

  More specifically, the first air supply duct 172 is provided behind the ceiling of the first-stage baking chamber (Pre-Heat) 96, and the second air supply duct 174 is behind the bottom wall of the first-stage baking chamber (Pre-Heat) 96. The third air supply duct 176 is provided behind the ceiling of the middle stage baking room (Bake 1) 98 and the final stage baking room (Bake 2) 100. Blowers 173, 175, and 177 are attached to the inlets of these air supply ducts 172, 174, and 176 to take outside air and pump the inside of the air supply duct to the outlet.

  In the first air supply duct 172, a heat exchanger 178 using the ceiling plate 96 a of the first-stage baking chamber (Pre-Heat) 96 and an air filter 180 are provided, and an inlet of the pre-bake unit (PRE-BAKE) 48 is provided. A hot air jet nozzle 182 is attached to the end of the duct of the hot air jet part 146H provided outside 84a (above the conveyance path 34).

  In the second air supply duct 174, a heat exchanger 184 and an air filter 186 using the bottom wall 96b of the first-stage baking chamber (Pre-Heat) 96 and the exhaust pipe 108 are provided, and a pre-bake unit (PRE-BAKE) is provided. ) A hot air jet nozzle 188 is attached to the end of the duct of the hot air jet part 146U provided outside the 48 inlet 84a (below the conveying path 34).

  In the third air supply duct 176, a heat exchanger 190 and an air filter 192 using the ceiling plate 98a of the middle-stage baking chamber (Bake1) 98 and the ceiling plate 100a of the final-stage baking chamber (Bake2) 100 are provided. A hot air jet nozzle 196 is attached to the end of the duct of the hot air jet part 194 provided inside the outlet 90a of the pre-bake unit (PRE-BAKE) 48 and above the conveying path 34. The hot air ejection part 194 is cut off from the heat insulation heating zone in the final stage baking chamber (Bake 2) 100 by the partition plate 198.

  In this way, by providing the warm air ejection section 194 inside the final stage baking chamber (Bake 2) 100, the warm air blown down from the warm air ejection section 194 flows out of the outlet 90a, and the atmosphere gas for baking is generated. It becomes difficult to leak out from the outlet 90a, and the baking temperature in the final-stage baking chamber (Bake2) 100 can be maintained more stably.

  In addition, in the air supply ducts 172, 174, 176, around the heat exchangers 178, 184, 190 (more preferably over the entire length of the air supply ducts 172, 174, 176), the heat exchangers 178, 184, 190 are provided. In order to prevent heat from escaping (and thereby increasing the efficiency of heat exchange), it is preferable to provide a wall of insulation.

  As another modified example, although not shown, a configuration in which the air supply duct or the air supply pipe of the hot air supply unit 140 is passed through the processing chamber (oven) of the pre-bake unit (PRE-BAKE) 48 is also possible. Moreover, the structure which provides the warm air ejection part of the warm air supply part 140 in the first stage baking chamber (Pre-Heat) 96 of the prebaking unit (PRE-BAKE) 48 is also possible.

  Further, the present invention is not limited to a pre-baking apparatus, but can be applied to any flat-flow type baking apparatus. For example, in the above-described coating and developing treatment system (FIG. 1), a post-bake unit (POST-BAKE) 55 is used. It is also applicable to.

  Although the above-described embodiment relates to a resist coating apparatus for FPD production, the present invention can be applied to any coating apparatus or application that supplies a processing liquid onto a substrate to be processed using a nozzle. 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.

Claims (21)

A substrate processing apparatus for performing heat treatment on a substrate to be processed,
A processing chamber having an inlet for unloading the substrate before processing into the room and an outlet for unloading the processed substrate outside of the room;
A transport section that horizontally traverses or crosses the interior of the processing chamber through the inlet and the outlet, and transports the substrate in a flat flow on the transport path;
A heating unit disposed along the transport path to heat the substrate on the transport path to a predetermined temperature;
An exhaust part for discharging the gas generated from the substrate by the heat treatment to the outside of the processing chamber;
A substrate processing apparatus comprising: a hot air supply unit that takes in air from outside the processing chamber, warms the captured air with waste heat generated in the processing chamber to generate warm air, and sends the warm air into the processing chamber .   2. The substrate processing apparatus according to claim 1, wherein the hot air supply unit includes a first hot air blowing unit that blows the hot air from the outside of the processing chamber toward the inlet or the vicinity thereof.   3. The substrate processing apparatus according to claim 2, further comprising a first air suction unit that sucks in gas around the transport path adjacent to the upstream side of the first hot air ejection unit in the substrate transport direction.   4. The substrate processing apparatus according to claim 3, further comprising a first partition plate for blocking an atmosphere between the first hot air ejection section and the first intake section.   The said warm air supply part has a 2nd warm air ejection part which ejects the said warm air toward the said exit or its vicinity from the outside of the said process chamber. Substrate processing equipment.   The said warm air supply part has a 2nd warm air ejection part which ejects the said warm air toward the said conveyance path in the said processing chamber near the said exit. Substrate processing equipment.   The substrate processing apparatus according to claim 6, further comprising a second air intake unit that sucks in gas around the transfer path adjacent to the downstream side of the second hot air ejection unit in the substrate transfer direction.   The substrate processing apparatus according to claim 7, further comprising a second partition plate configured to block an atmosphere between the second hot air ejection unit and the second intake unit.   The substrate processing apparatus according to claim 1, wherein the hot air supply unit includes an air filter for removing foreign matters or contaminants contained in air taken from outside the processing chamber. .   The hot air supply unit has a breathable heat exchanger thermally coupled to the processing chamber, passes air taken from outside the processing chamber through the heat exchanger, and in the heat exchanger The substrate processing apparatus according to claim 1, wherein the warm air is generated by transferring heat from the processing chamber to air.   The substrate processing apparatus according to claim 10, wherein the heat exchanger is thermally coupled to a ceiling wall of the processing chamber.   The substrate processing apparatus according to claim 10, wherein the heat exchanger is thermally coupled to a bottom wall of the processing chamber.   The substrate processing apparatus according to claim 10, wherein the heat exchanger is thermally coupled to an exhaust pipe of the exhaust unit.   The substrate processing apparatus according to claim 10, wherein an air passage of the heat exchanger passes through the processing chamber.   The substrate processing apparatus according to claim 10, wherein an air passage of the heat exchanger has a labyrinth structure.   The substrate processing apparatus according to claim 10, wherein an air passage of the heat exchanger is configured by a pipe.   The substrate processing apparatus as described in any one of Claims 10-16 with which the metal mesh which consists of a material with high heat conductivity is provided in the middle of the air path of the said heat exchanger.   The substrate processing apparatus according to claim 10, wherein a heat insulating material is provided around the heat exchanger to prevent heat of the heat exchanger from escaping to the outside.   The substrate processing apparatus according to claim 1, wherein the hot air supply unit includes a temperature control unit for controlling a temperature of the hot air. The processing chamber is divided into a plurality of baking chambers along the transfer path,
The heating unit is provided with a heater for heating the substrate at an independent set temperature in each of the baking chambers.
The substrate processing apparatus as described in any one of Claims 1-19.   21. The substrate processing apparatus according to claim 20, wherein the temperature in the baking chamber closest to the entrance of the processing chamber is the highest among the plurality of baking chambers.

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