JP4832576B2 - Application processing equipment - Google Patents

Description

  The present invention relates to a coating processing apparatus that applies a coating solution such as a resist solution to a substrate such as a glass substrate for a liquid crystal display device.

  For example, in a manufacturing process of a liquid crystal display (LCD) or a semiconductor device, a predetermined circuit pattern is formed on a glass substrate or a semiconductor wafer by using a photolithography technique. In this photolithography technique, a coating process is performed in which a resist solution is supplied to a glass substrate to form a coating film, which is then dried, and subsequently an exposure process and a development process are sequentially performed.

  Among these, in the resist coating process, a glass substrate or the like is rotated, a resist solution is dropped on the substrate surface from directly above the center of rotation, and the resist solution is spread over the entire surface of the substrate by centrifugal force, and a slit type nozzle Slit coating is used to form a resist film having a predetermined film thickness by linearly moving the substrate and the nozzle while discharging the resist solution from the substrate.

  In any coating method, the film thickness and the like change depending on the viscosity of the resist solution, and the viscosity of the resist solution is determined by the blending ratio of the resist and a solvent such as thinner added to the resist solution. It is directed to perform an appropriate coating process by changing the blending ratio of resist and thinner according to the above.

  However, when resist solutions having different blending ratios are used, it is necessary to replace each tank, and various resist solution tanks having different viscosities must be prepared in advance in order to meet the demand for changing the resist film thickness. Furthermore, even when resist solutions having the same viscosity are used, resist films having the same film thickness may not always be obtained due to differences in daily environmental conditions. In such a case, it is desired to deal with the resist solution with a slightly different viscosity, but such fine adjustment is difficult.

  As a technique for solving such a problem, Patent Document 1 discloses that a resist and a solvent are mixed in-line at a predetermined ratio, and the resist solution thus mixed is subjected to a substrate to be processed such as a semiconductor wafer through a nozzle. The technology to supply is proposed.

  However, the above-mentioned Patent Document 1 does not disclose means for verifying whether or not the composition is actually correct. If the composition is deviated from the predetermined one, the film thickness of the first substrate to be processed is predetermined. If it is out of the range, the resist used for the substrate to be processed is wasted, and it is necessary to discard the resist solution existing in the pipe 88 shown in FIG. The liquid is wasted. In particular, glass substrates for LCDs have become increasingly large in size recently, leading to the emergence of enormous ones with a length of 2 m on each side, and such waste of resist solution cannot be ignored. . Furthermore, when performing such a retry, the time is wasted and the throughput is reduced.

Japanese Patent Laid-Open No. 10-242045

The present invention has been made in view of such circumstances, and a coating processing apparatus capable of adjusting the viscosity of a resist solution in-line while suppressing wasteful consumption of the resist solution as much as possible and reducing the throughput, and an object of the present invention is to provide a coating process how.

In order to solve the above problems, in one aspect of the present invention, a high-concentration coating liquid sending part that sends out a high-concentration coating liquid, a solvent sending part that sends out a solvent, and the high-concentration coating liquid sending part and the solvent sending part A mixing unit that is connected to a pipe and mixes the high-concentration coating solution and the solvent to form a diluted coating solution diluted to a predetermined concentration; and a coating solution that discharges the diluted coating solution to form a coating film on the substrate A discharge mechanism, a diluted application liquid supply pipe for supplying the diluted application liquid from the mixing section toward the application liquid discharge mechanism, and the diluted application liquid from the diluted application liquid supply pipe are temporarily stored. Each of the buffer tank and the diluted coating liquid supply pipe, each of the buffer tank and the diluted coating liquid supply pipe having a supply pump for supplying the diluted coating liquid from the buffer tank to the coating liquid discharge mechanism. Connected and before From one buffer tank and the diluting the coating liquid feed pipeline takes in the dilution coating solution, and diluting the coating liquid circulating unit for circulating back to the mixing unit, the diluted coating liquid feeding destination the coating solution discharge mechanism side of And a first switching mechanism that switches between the diluted coating liquid circulating unit side.

  According to the present invention, the concentration adjustment is performed by mixing the high-concentration coating solution and the solvent in-line, and the adjustment is performed when the blending ratio is deviated, so that waste of the coating solution can be prevented as much as possible. .

1 is a schematic plan view showing a resist coating / development processing system including a resist coating apparatus according to an embodiment of the present invention. 1 is a schematic plan view showing a resist coating apparatus according to an embodiment of the present invention. Sectional drawing which shows schematic structure of the board | substrate conveyance mechanism of the resist coating apparatus which concerns on one Embodiment of this invention. 1 is a schematic perspective view showing a resist supply nozzle of a resist coating apparatus according to an embodiment of the present invention. The schematic block diagram which shows the resist liquid supply system in the resist coating apparatus which concerns on one Embodiment of this invention with a control system. The flowchart explaining the procedure of a resist liquid application | coating process. The figure which shows the procedure of carrying out monitor application | coating of the dilution resist liquid on a roller, and measuring the film thickness of the monitor application film | membrane of a dry state. The figure which shows the procedure of carrying out monitor application | coating of the dilution resist liquid on a glass substrate, and measuring the film thickness of the dry monitor application film. The figure which shows an example of the apparatus which apply | coats a dilution resist on the moving belt and monitors the film thickness of the dry monitor coating film. The figure which shows the other example of the apparatus which carries out the monitor application | coating of the dilution resist on the moving belt, and measures the film thickness of the monitor coating film of a dry state. The figure which shows the procedure for apply | coating the diluted resist liquid to a roller and carrying out monitor application | coating, and obtaining the film thickness of a monitor application film | membrane from the time-dependent change of the film thickness of the monitor application film | membrane of a wet state. The figure which shows the procedure for apply | coating a diluted resist solution to a glass substrate on a monitor, and obtaining the film thickness of a monitor coating film from the time-dependent change of the film thickness of the monitor coating film of a wet state. The figure which shows an example of the apparatus which carries out the monitor application | coating of the dilution resist on the moving belt, and measures the film thickness of the monitor application film | membrane of a wet state. The graph which shows an example of a time-dependent change of wet film thickness.

Hereinafter, embodiments of the present invention will be specifically described with reference to the accompanying drawings.
FIG. 1 is a schematic plan view of a resist coating / developing system applied to resist coating and development after exposure on an LCD glass substrate on which a coating processing apparatus according to an embodiment of the present invention is mounted.

  This resist coating / development processing system 100 includes a cassette station 1 on which a cassette C that accommodates a plurality of LCD glass substrates (hereinafter simply referred to as substrates) G is placed, and a series of processes including resist coating and development on the substrate G. A processing station 2 having a plurality of processing units for performing processing, and an interface station 3 for transferring the substrate G to and from the exposure apparatus 4. The cassette station 1 and the interface station 3 each perform processing. It is arranged at both ends of the station 2. In FIG. 1, the longitudinal direction of the resist coating / development processing system 100 is the X direction, and the direction perpendicular to the X direction on the plane is the Y direction.

  The cassette station 1 includes a mounting table 9 on which the cassette C can be mounted in the Y direction, and a transfer device 11 for loading and unloading the substrate G between the processing station 2 and the mounting table 9. The cassette C is transported between the two. The transfer device 11 has a transfer arm 11a, and can move on a transfer path 10 provided along the Y direction, which is the arrangement direction of the cassette C. The transfer arm 11a moves between the cassette C and the processing station 2. The board | substrate G is carried in / out.

  The processing station 2 basically has two parallel rows of transfer lines A and B for transferring the substrate G extending in the X direction. From the cassette station 1 side toward the interface station 3 along the transfer line A. A scrub cleaning processing unit (SCR) 21, a first thermal processing unit section 26, a resist processing unit 23, and a second thermal processing unit section 27 are arranged.

  Further, from the interface station 3 side toward the cassette station 1 along the transfer line B, the second thermal processing unit section 27, the development processing unit (DEV) 24, and the i-line UV irradiation unit (i-UV) 25 and a third thermal processing unit section 28 are arranged. An excimer UV irradiation unit (e-UV) 22 is provided on a part of the scrub cleaning unit (SCR) 21. An excimer UV irradiation unit (e-UV) 22 is provided to remove organic substances on the substrate G prior to scrubber cleaning, and an i-line UV irradiation unit (i-UV) 25 is used to perform a decoloring process for development. Provided.

  In the scrub cleaning unit (SCR) 21, the cleaning process and the drying process are performed while the substrate G is transported in a substantially horizontal posture. In the development processing unit (DEV) 24, the developer coating, rinsing, and drying processes are sequentially performed while the substrate G is transported in a substantially horizontal posture. In the scrub cleaning processing unit (SCR) 21 and the development processing unit (DEV) 24, the substrate G is transported by, for example, roller transport or belt transport, and the transport inlet and the transport outlet of the substrate G are provided on opposite short sides. It has been. Further, the transport of the substrate G to the i-line UV irradiation unit (i-UV) 25 is continuously performed by a mechanism similar to the transport mechanism of the development processing unit (DEV) 24.

  The resist processing unit 23 supplies the resist solution while transporting the substrate G in a substantially horizontal posture, and exposes the substrate G to a reduced-pressure atmosphere according to the resist coating apparatus (CT) 23a according to this embodiment that forms a coating film. And a reduced-pressure drying device (VD) 23b for evaporating volatile components contained in the coating film formed on the substrate G and drying the coating film. The resist coating apparatus (CT) 23a will be described in detail later.

  The first thermal processing unit section 26 includes two thermal processing unit blocks (TB) 31 and 32 configured by stacking thermal processing units for performing thermal processing on the substrate G, The thermal processing unit block (TB) 31 is provided on the scrub cleaning processing unit (SCR) 21 side, and the thermal processing unit block (TB) 32 is provided on the resist processing unit 23 side. A first transport device 33 is provided between the two thermal processing unit blocks (TB) 31 and 32.

  The thermal processing unit block (TB) 31 includes a pass unit that transfers the substrate G in order from the bottom, two dehydration bake units that perform a dehydration bake process on the substrate G, and a hydrophobic process on the substrate G. The adhesion processing unit to be applied has a configuration in which it is stacked in four stages. The thermal processing unit block (TB) 32 includes a pass unit that transfers the substrate G in order from the bottom, two cooling units that cool the substrate G, and an adhesion that performs a hydrophobic treatment on the substrate G. It has a configuration in which processing units are stacked in four stages.

  The first transfer device 33 receives the substrate G from the scrub cleaning processing unit (SCR) 21 through the pass unit, carries in and out the substrate G between the thermal processing units, and resists through the pass unit. The substrate G is transferred to the processing unit 23.

  The first transfer device 33 can move up and down, move back and forth, and turn, and can access any of the thermal processing unit blocks (TB) 31 and 32.

  The second thermal processing unit section 27 includes two thermal processing unit blocks (TB) 34 and 35 configured by stacking thermal processing units for performing thermal processing on the substrate G, The thermal processing unit block (TB) 34 is provided on the resist processing unit 23 side, and the thermal processing unit block (TB) 35 is provided on the development processing unit (DEV) 24 side. A second transport device 36 is provided between the two thermal processing unit blocks (TB) 34 and 35.

  The thermal processing unit block (TB) 34 has a configuration in which a pass unit for transferring the substrate G and three pre-baking units for performing a pre-baking process on the substrate G are stacked in four stages from the bottom. The thermal processing unit block (TB) 35 includes four pass units for transferring the substrate G in order from the bottom, a cooling unit for cooling the substrate G, and two pre-baking units for pre-baking the substrate G. It is the structure laminated | stacked on the step.

  The second transfer device 36 receives the substrate G from the resist processing unit 23 through the pass unit, carries in and out the substrate G between the thermal processing units, and develops the processing unit (DEV) through the pass unit. The substrate G is transferred to and received from the extension cooling stage (EXT / COL) 44, which is a substrate transfer section of the interface station 3 to be described later. The second transfer device 36 has the same structure as the first transfer device 33, and can access any of the thermal processing unit blocks (TB) 34 and 35.

  The third thermal processing unit section 28 includes two thermal processing unit blocks (TB) 37 and 38 formed by stacking thermal processing units for performing thermal processing on the substrate G, The thermal processing unit block (TB) 37 is provided on the development processing unit (DEV) 24 side, and the thermal processing unit block (TB) 38 is provided on the cassette station 1 side. A third transfer device 39 is provided between the two thermal processing unit blocks (TB) 37 and 38.

  The thermal processing unit block (TB) 37 has, in order from the bottom, a pass unit that transfers the substrate G and three post-bake units that perform post-bake processing on the substrate G, which are stacked in four stages. is doing. Further, the thermal processing unit block (TB) 38 includes, in order from the bottom, a post-baking unit, a pass / cooling unit for transferring and cooling the substrate G, and two post-baking processes for post-baking the substrate G. The unit has a configuration in which four units are stacked.

  The third transfer device 39 receives the substrate G from the i-ray UV irradiation unit (i-UV) 25 through the pass unit, carries the substrate G in and out of the thermal processing unit, and passes the pass / cooling unit. Then, the substrate G is transferred to the cassette station 1. The third transport device 39 has the same structure as the first transport device 33 and can access any of the thermal processing unit blocks (TB) 37 and 38.

  In the processing station 2, the processing units and the transport devices are arranged so as to form the transport lines A and B in two rows as described above and basically in the order of processing. A space 40 is provided between B. A shuttle (substrate mounting member) 41 is provided so as to be able to reciprocate in the space 40. The shuttle 41 is configured to hold the substrate G, and the substrate G is transferred between the transfer lines A and B via the shuttle 41. Delivery of the substrate G to the shuttle 41 is performed by the first to third transfer devices 33, 36, and 39.

  The interface station 3 includes a transfer device 42 that loads and unloads the substrate G between the processing station 2 and the exposure device 4, a buffer stage (BUF) 43 that places a buffer cassette, and a substrate transfer unit that has a cooling function. There is an extension / cooling stage (EXT / COL) 44, and an external device block 45 in which a titler (TITLER) and a peripheral exposure device (EE) are vertically stacked is provided adjacent to the transfer device 42. ing. The transfer device 42 includes a transfer arm 42 a, and the transfer arm 42 a carries in and out the substrate G between the processing station 2 and the exposure device 4.

  Next, an outline of the processing operation in the resist coating / development processing system 100 configured as described above will be described. First, the substrate G in the cassette C disposed on the mounting table 9 of the cassette station 1 is directly carried into the excimer UV irradiation unit (e-UV) 22 of the processing station 2 by the transfer device 11, and scrub pretreatment is performed. . Next, the substrate G is carried into the scrub cleaning unit (SCR) 21 by the transfer device 11 and scrubbed. After the scrub cleaning process, the substrate G is carried out to the pass unit of the thermal processing unit block (TB) 31 belonging to the first thermal processing unit section 26 by, for example, roller conveyance.

  The substrate G placed in the pass unit of the thermal processing unit block (TB) 31 is first transported to the dehydration bake unit of the thermal processing unit block (TB) 31 and subjected to heat treatment, and then the thermal processing unit block. (TB) Adhesion processing unit of thermal processing unit block (TB) 31 and adhesion processing of thermal processing unit block (TB) 32 in order to improve the fixability of the resist after being transferred to the cooling unit of 32 and cooled. It is transported to one of the units, where it is subjected to an adhesion process (hydrophobization process) by HMDS. Thereafter, the substrate G is transferred to the cooling unit, cooled, and further transferred to the pass unit of the thermal processing unit block (TB) 32. All of the transfer processing of the substrate G when performing such a series of processing is performed by the first transfer device 33.

  The substrate G disposed in the pass unit of the thermal processing unit block (TB) 32 is carried into the resist processing unit 23 by a substrate transport mechanism such as a roller transport mechanism provided in the pass unit. In the resist coating apparatus (CT) 23a, a resist solution is supplied while the substrate G is conveyed in a horizontal posture to form a coating film, and then the coating film is subjected to a vacuum drying process in a vacuum drying apparatus (VD) 23b. Is done. Thereafter, the substrate G is transferred from the resist processing unit 23 to the pass unit of the thermal processing unit block (TB) 34 belonging to the second thermal processing unit section 27 by the substrate transfer arm provided in the vacuum drying apparatus (VD) 23b. Delivered.

  The substrate G arranged in the pass unit of the thermal processing unit block (TB) 34 is pre-baked and thermal processing unit block (TB) 35 of the thermal processing unit block (TB) 34 by the second transfer device 36. The pre-baking unit is transported to any one of the pre-baking units, and is then transported to the cooling unit of the thermal processing unit block (TB) 35 to be cooled to a predetermined temperature. Then, it is further transported to the pass unit of the thermal processing unit block (TB) 35 by the second transport device 36.

  Thereafter, the substrate G is transferred to the extension / cooling stage (EXT / COL) 44 of the interface station 3 by the second transfer device 36, and the peripheral exposure of the external device block 45 is performed by the transfer device 42 of the interface station 3 as necessary. It is conveyed to an apparatus (EE), where exposure for removing the outer peripheral portion (unnecessary portion) of the resist film is performed. Next, the substrate G is transported to the exposure device 4 by the transport device 42, where the resist film on the substrate G is subjected to exposure processing in a predetermined pattern. The substrate G may be temporarily stored in a buffer cassette on the buffer stage (BUF) 43 and then transferred to the exposure apparatus 4.

  After the exposure is completed, the substrate G is loaded into the upper titler (TITLER) of the external device block 45 by the transfer device 42 of the interface station 3 and predetermined information is written on the substrate G, and then the extension / cooling stage (EXT / COL). ) 44. The substrate G is transferred from the extension / cooling stage (EXT / COL) 44 to the pass unit of the thermal processing unit block (TB) 35 belonging to the second thermal processing unit section 27 by the second transfer device 36. .

  By, for example, a roller transport mechanism extending from the pass unit of the thermal processing unit block (TB) 35 to the development processing unit (DEV) 24, the substrate G is moved to the pass unit of the thermal processing unit block (TB) 35. Are carried into a development processing unit (DEV) 24. In the development processing unit (DEV) 24, for example, the developer is accumulated on the substrate G while the substrate is conveyed in a horizontal posture, and then the conveyance of the substrate G is temporarily stopped and the substrate G is inclined by a predetermined angle. Then, the developer on the substrate G is poured off, and in this state, a rinse solution is supplied to the substrate G to wash away the developer. Thereafter, the substrate G is returned to the horizontal posture, and the conveyance is started again, and the substrate G is dried by blowing nitrogen gas or air for drying onto the substrate G.

  After the development processing is completed, the substrate G is transported from the development processing unit (DEV) 24 to the i-line UV irradiation unit (i-UV) 25 by a continuous transport mechanism, for example, roller transport, and the substrate G is subjected to decolorization processing. The Thereafter, the substrate G is carried out to the pass unit of the thermal processing unit block (TB) 37 belonging to the third thermal processing unit section 28 by the roller transport mechanism in the i-line UV irradiation unit (i-UV) 25.

  The substrate G placed in the pass unit of the thermal processing unit block (TB) 37 is post-baked by the third transfer device 39 and the post-baking unit of the thermal processing unit block (TB) 37 and the thermal processing unit block (TB) 38. After being transferred to one of the post-baking units and post-baked, and then transferred to the pass / cooling unit of the thermal processing unit block (TB) 38 and cooled to a predetermined temperature, the transfer device 11 of the cassette station 1 Is accommodated in a predetermined cassette C arranged in the cassette station 1.

Next, the resist coating apparatus (CT) 23a will be described in detail.
FIG. 2 is a schematic plan view of a resist coating apparatus (CT) 23a. The resist coating apparatus (CT) 23a includes a stage 12 provided with a plurality of gas injection ports 16 for injecting a predetermined gas to a predetermined position on the surface, and substrate transfer for transferring the substrate G in the X direction on the stage 12 A mechanism 13, a resist supply nozzle 14 for supplying a resist solution to the surface of the substrate G moving on the stage 12, and a nozzle cleaning unit 15 for cleaning the resist supply nozzle 14 are provided.

  The stage 12 is roughly divided into an introduction stage portion 12a, a coating stage portion 12b, and a carry-out stage portion 12c from upstream to downstream in the transport direction of the substrate G. The introduction stage unit 12a is an area for transporting the substrate G from the pass unit of the thermal processing unit block (TB) 32 to the coating stage unit 12b. A resist supply nozzle 14 is disposed in the coating stage unit 12b, and a resist solution is discharged from the resist supply nozzle 14 while causing a linear relative movement between the substrate G and the resist supply nozzle 14 to obtain a substrate. A resist solution is scan-coated on G. The carry-out stage unit 12c is an area for carrying the substrate G on which the coating film is formed to the reduced pressure drying apparatus (VD) 23b.

  The substrate G is held in a horizontal posture and floated from the stage 12 by the gas ejected from the gas ejection port 16, and is transported by the substrate transport mechanism 13 in this state.

  In addition to the gas injection port 16, the unloading stage portion 12 c of the stage 12 is provided with lift pins 47 that lift the substrate G in order to deliver the substrate G transferred to the unloading stage portion 12 c to the substrate transfer arm 19. Yes.

  FIG. 3 is a cross-sectional view showing a schematic configuration of the substrate transport mechanism 13. The substrate transport mechanism 13 includes substrate holding members 51a and 51b that hold a part of the Y direction end of the substrate G, and linear guides 52a and 52b that are arranged on the side surface in the Y direction of the stage 12 so as to extend in the X direction. A connecting member 50 that holds the substrate holding members 51a and 51b and is fitted to the linear guides 52a and 52b, and an X-axis drive mechanism 53 that reciprocates the connecting member 50 in the X direction.

  Each of the substrate holding members 51a and 51b has a structure in which one or more suction pads 48 for sucking and holding the substrate G are provided on the pedestal portion 49. The suction pads 48 operate a vacuum pump or the like (not shown). Thus, the substrate G can be sucked and held. The suction pad 48 holds the substrate G on the back surface side of the substrate G where the resist solution is not applied, that is, in the vicinity of the Y-direction end of the back surface of the substrate G. Examples of the X-axis drive mechanism 53 include a belt drive mechanism, a ball screw, an air slider, an electric slider, and a linear motor.

  FIG. 4 is a perspective view showing a schematic structure of the resist supply nozzle 14. The resist supply nozzle 14 has a structure in which a slit-like resist discharge port 14b for discharging a resist solution in a substantially strip shape is provided in a long box body 14a that is long in one direction. The resist supply nozzle 14 is provided with a sensor (not shown) for measuring the distance between the resist discharge port 14b and the substrate G, and the resist used when supplying the resist solution to the substrate G based on the measured value of the sensor. The position of the supply nozzle 14 is controlled.

Next, the resist solution supply system will be described.
FIG. 5 is a view showing a resist solution supply system in the resist coating apparatus (CT) 23a together with a control system. The resist solution supply system of this embodiment includes a high concentration resist solution tank 61 in which a high concentration resist solution is stored, a solvent tank 64 in which, for example, thinner is stored as a solvent for diluting the resist solution, and a high concentration resist solution and a solvent. And a mixing unit 70 for mixing the two. The mixing unit 70 joins the high-concentration resist solution and the solvent in a turbulent state, and a confluence block 67 for increasing the Reynolds number and a large number of baffle plates are provided to pass through the high-concentration resist solution and the solvent. And a static mixer 68 for more reliably mixing. In this manner, the high concentration resist solution and the solvent are mixed by the mixing unit 70 to form a diluted resist solution.

  The high-concentration resist solution tank 61 and the junction block 67 are connected by a pipe 62. A high-concentration resist solution pump 63 is provided in the pipe 62, and the high-concentration resist solution tank 61 has a high concentration resist solution. It is supplied to the confluence block 67 by the concentration resist solution pump 63. On the other hand, the solvent tank 64 and the merging block are connected by a pipe 65, and a solvent pump 66 is provided in the pipe 65, and the solvent in the solvent tank 64, for example, thinner, is supplied to the merging block 67 by the solvent pump 66. Is done. The pipe 62 and the pipe 65 have a small diameter, and the liquid is easily turbulent.

  A diluted resist solution supply pipe 69 is provided so as to extend from the junction block 67 to the resist solution discharge nozzle 14 side, and the static mixer 68 is provided in the diluted resist solution supply pipe 69. The diluted resist solution supply pipe 69 is connected to two buffer tanks 71a and 71b via pipes 69a and 69b, and the diluted resist solution adjusted to a predetermined composition by the mixing unit 70 is the buffer tanks 71a and 71b. To be supplied. The buffer tanks 71a and 71b are connected to a pipe 73 that reaches the resist solution discharge nozzle 14 via pipes 72a and 72b provided at the bottom thereof, and the pipe 73 is provided with a resist solution supply pump 74. When the pump 74 is operated, the diluted resist solution is supplied to the resist solution discharge nozzle 14 from either of the buffer tanks 71a and 71b. On the other hand, the pipes 69a and 69b are provided with opening / closing valves 75a and 75b, respectively, and the pipes 72a and 72b are provided with opening / closing valves 76a and 76b. By opening and closing these valves, the resist solution is selectively supplied to either of the buffer tanks 71a and 71b, and the resist solution is selectively discharged from either of the buffer tanks 71a and 71b. The buffer tanks 71a, 71b, the resist solution supply pump 74, the pipes 69a, 69b, 72a, 72b, 73 and the valves 76a, 76b constitute a resist solution supply mechanism.

  On the other hand, a monitoring buffer tank 77 is connected to the buffer tanks 71a and 71b in the piping 69 via a circulation piping 69c. A circulation pipe 82c is connected to the bottom of the monitor buffer tank 77, and a return pipe 82 is connected to the circulation pipe 82c. The return pipe 82 is connected to a portion of the pipe 69 between the junction block 67 and the static mixer 68 via a three-way valve 76. The return pipe 82 is provided with a circulation pump 84, and a circulation line that reaches the pipe 69 via the pipe 69, the monitor buffer tank 77, the circulation pipe 82c, the return pipe 82, and the three-way valve 76 is configured. Yes. A valve 75c is provided in the pipe 69c leading to the monitor buffer tank 77. By operating the valves 75a and 75b and the valves 75c provided in the pipes 69a and 69b leading to the buffer tanks 71a and 71b described above, The diluted resist solution can be switched between the resist supply mechanism side and the circulation line side. That is, the valves 75a, 75b, and 75c function as these switching mechanisms.

  Buffer tanks 71 a and 71 b are also connected to the return pipe 82 via pipes 82 a and 82 b, respectively, and the resist solution can be returned from the buffer tanks 71 a and 71 b by the circulation pump 84. The pipes 82a, 82b, 82c are provided with opening / closing valves 83a, 83b, 83c.

  In addition to the pipe 82c, a monitor pipe 78 is connected to the bottom of the monitor buffer tank 77, and a monitor application discharge nozzle 79 is connected to the other end of the pipe 78. The pipe 78 is provided with a monitor application pump 80. By operating the pump 80, the monitor buffer tank 77 is passed through the monitor pipe 78 and diluted to a monitor application discharge nozzle 79 to a predetermined mixing ratio. The diluted resist solution is supplied. The piping 78 is provided with an opening / closing valve 81.

  The resist solution discharged from the monitor application discharge nozzle 79 is applied to an appropriate object to be applied, for example, a roller or a glass substrate. A film thickness measuring device 85 is provided in the vicinity of the monitor application discharge nozzle 79 and measures the film thickness of the coating film formed by the monitor application.

  As the pumps 63, 66, 74, 80, 84, bellows pumps, diaphragm pumps, synringe pumps, etc. that are generally used in this field can be used.

  The controller 90 controls the resist coating apparatus (CT) 23a including the control of the resist solution supply system. The controller 90 controls the pumps 63, 66, 74, 80, 84 and all valves, and further controls other components such as various drive mechanisms. For the resist solution supply system, the pumps 63 and 66 are controlled on the basis of the result of measuring the film thickness of the film formed by the above-described monitoring coating with the film thickness measuring device 85, and the height in the resist solution tank 61 is controlled. The mixing ratio of the resist solution having a concentration and a solvent such as thinner in the solvent tank 64 is finely adjusted, and the supply destination of the diluted resist solution mixed and diluted is controlled.

  The controller 90 is controlled by a host process controller 92 that controls the entire resist coating / development processing system 100. The controller 90 and the process controller 92 are configured by a computer.

  The process controller 92 controls each component of the resist coating / development processing system 100 in addition to the control of the pump and the valve via the controller 90 as described above. The process controller 92 includes a keyboard for a process manager to input a command to manage the resist coating / developing system 100, a display for visualizing and displaying the operating status of the resist coating / developing system 100, and the like. A user interface 93 is connected.

  Further, the process controller 92 processes various components executed by the resist coating / developing system 100 under the control of the process controller 92 and processes each component of the plasma etching apparatus according to the processing conditions. Is connected to a storage unit 94 in which a program, that is, a recipe is stored. The stored recipe includes control of pumps and valves by the controller 90.

  The recipe may be stored in a hard disk or a semiconductor memory, or may be set at a predetermined position in the storage unit 94 while being stored in a portable storage medium such as a CDROM or DVD. Furthermore, you may make it transmit a recipe suitably from another apparatus via a dedicated line, for example.

  Then, if necessary, an arbitrary recipe is called from the storage unit 94 by an instruction from the user interface 93 and is executed by the process controller 92, so that the resist application / development system can control the process under the control of the process controller 92. Desired processing is performed.

  Next, the processing operation in the resist coating apparatus (CT) 23a configured as described above will be described.

  First, each part of the stage 12 is brought into a state where the substrate G can be floated to a predetermined height, and the substrate G is caused to enter the introduction stage part 12a from the path unit of the heat treatment unit block (TB) 32 by the roller transport mechanism. In a state where a part of G is still supported by the rollers, the substrate holding members 51 a and 51 b hold the end of the substrate G in the Y direction, and the floating substrate G is carried into the introduction stage portion 12 a of the stage 12.

  When the substrate G passes under the resist supply nozzle 14 disposed at a predetermined position, a resist solution is supplied from the resist supply nozzle 14 to the surface of the substrate G, and a coating film is formed.

Hereinafter, the procedure of the resist solution coating process will be described with reference to the flowchart of FIG.
First, a high concentration resist solution and a solvent are mixed at a predetermined ratio from a high concentration resist solution tank 61 in which a high concentration resist solution is stored and a solvent tank 64 in which, for example, thinner is stored as a solvent for diluting the resist solution. (Step 1). The ratio between the high concentration resist solution and the solvent at this time is defined in the recipe, and a command is output to the high concentration resist solution pump 63 and the solvent pump 66 via the process controller 92 and the controller 90 based on the information. The

  The high-concentration resist solution and the solvent supplied to the mixing unit 70 are mixed by the merge block 67 and the static mixer 68 to obtain a diluted resist solution in a sufficiently mixed state (step 2). Then, the valve 75c is opened, the valves 75a and 75b are closed, the valve 83c is opened and the 81 is closed, and the circulation pump 84 is driven to connect the pipe 69, the monitor resist solution tank 77, the pipe 82c, the return pipe 82, and A circulation line that reaches the pipe 69 again through the three-way valve 76 is formed, and the diluted resist solution formed by mixing the high-concentration resist and the solvent as described above is circulated (step 3).

  Next, the valve 81 is opened, and the monitor coating pump 80 is driven to take out the diluted resist solution from the monitor buffer tank 77 constituting the circulation line, and supply the diluted resist solution to the monitor coating discharge nozzle 79. The mixed liquid (resist liquid) is discharged from 79 to perform monitor coating, and the film thickness of the monitor coating film is measured (step 4). The film thickness of the monitor coating film is used as a parameter serving as an index of the blending ratio of the high concentration resist solution and the solvent.

  This step can be performed according to the procedure shown in FIGS. In the example of FIG. 7, a diluted resist solution is supplied onto the roller 95 from the monitor application discharge nozzle 79 to form a coating film on the roller 95, and then heat-treated ((a) of FIG. 7). The thickness of the monitor coating film formed on the roller 95 is measured by the thickness measuring device 85 (FIG. 7B), and then the roller 95 is washed (FIG. 7C). In the example of FIG. 8, a diluted resist solution is supplied onto the small glass substrate 96 from the monitor coating discharge nozzle 79 to form a coating film on the glass substrate 96, and then heat-treated ((a) of FIG. 8), Thereafter, the film thickness of the monitor coating film formed on the glass substrate 96 is measured by the film thickness measuring device 85 (FIG. 8B), and then the glass substrate 96 is washed (FIG. 8C). . In these monitor coatings, since the film thickness is not stable immediately after the start of coating, the film thickness in the latter half (after 100 mm from the coating start point) is measured in either case of the roller 95 or the glass substrate 96.

  Further, monitor coating and film thickness measurement can also be performed by an apparatus using a belt shown in FIG. 9 or FIG.

  In the apparatus shown in FIG. 9, for example, a steel belt 101 is wound around the upper rollers 102 and 103 and the lower rollers 104 and 105, a monitor application discharge nozzle 79 is disposed immediately above one upper roller 102, and the other upper roller A film thickness measuring device 85 is disposed immediately above 103, and a small vacuum drying device 106 is disposed between them so that the belt 101 passes between them. A cleaning tank 107 storing a cleaning liquid made of a solvent such as thinner is disposed between the lower rolls 104 and 105 of the belt 101 so that the belt 101 is immersed in the cleaning liquid in the cleaning tank 107. It has become. A spray rinse nozzle 108 and a gas blow nozzle 109 are arranged between the lower roller 105 and the upper roller 102.

  In such an apparatus, while the belt 101 is moved in the direction of the arrow by a belt driving device (not shown), a diluted resist solution is discharged onto the belt 101 from the monitor application discharge nozzle 79 to form a coating film, and a small pressure reduction The coating film is dried by the drying device 106, and the film thickness of the coating film after drying is measured by the film thickness measuring device 85. Thereafter, the coating film on the belt 101 is washed and removed by the washing tank 107, rinsed by the spray rinse nozzle 108, dried by gas blowing from the gas blow nozzle 109, and subsequently the next monitor coating is performed in the same manner.

  With such an apparatus, it is possible to perform film thickness measurement that is an index of the blending ratio of the high-concentration resist solution and the solvent with higher accuracy. Further, since the application by the monitor application discharge nozzle 79 is performed on the roller, the gap control is easy. Further, since the film thickness measuring device 85 is also provided immediately above the roller, the film thickness can be measured stably and with high accuracy without being affected by the bending of the belt 101 or the like. Furthermore, the pressure reduction of the small-sized vacuum drying apparatus 106 can be performed by branching a pipe from the vacuum pump provided in the vacuum drying unit (VD) 23b, and there is no need to add a new vacuum pump.

  The apparatus shown in FIG. 10 is provided with a heater 110 in place of the vacuum drying apparatus 106 so as to be completely dried. Thereby, since it becomes a real film thickness substantially, a precision can be raised more. Since the belt 101 is heated by the heater 110, a cooling blow nozzle 111 is provided on the downstream side of the upper roller 103. An oven may be arranged in place of the heater 110.

  The example of measuring the coating film in a state where the resist solution is dried has been described above, but the change with time of the film thickness in the wet state may be measured according to the procedure shown in FIGS. In the example of FIG. 11, a diluted resist solution is supplied onto the roller 95 from the monitor application discharge nozzle 79 to form a coating film on the roller 95 (FIG. 11 (a)), and then the film thickness is measured in a wet state. The change with time (two or more points) of the coating film formed on the roller 95 is measured by the device 85 ((b) in FIG. 11), and then the roller 95 is washed ((c) in FIG. 11). In the example of FIG. 12, a diluted resist solution is supplied onto the small glass substrate 96 from the monitor application discharge nozzle 79 to form a coating film on the glass substrate 96 (FIG. 12A), and then in a wet state. The change over time (two or more points) of the coating film formed on the glass substrate 96 is measured by the film thickness measuring device 85 ((b) in FIG. 12), and then the glass substrate 96 is washed ((c in FIG. 12). )).

  The apparatus shown in FIG. 13 is obtained by removing the vacuum drying apparatus 106 from the apparatus shown in FIG. 9, and forms a coating film by supplying a diluted resist solution onto the belt 101 from the monitor application discharge nozzle 79, and then in a wet state. Measure the change in film thickness over time.

  The change with time of the wet film thickness is as shown in the graph of FIG. 14, for example, and the dry film thickness after the solvent volatilization is calculated from such a graph using an appropriate algorithm. If the correct optical constant and the formed film thickness of the film to be measured can be grasped, the predicted calculated film thickness can be displayed at the same time regardless of before or after baking.

  The apparatus shown in FIG. 9 can shorten the tact time in a series of operations of monitor coating and film thickness measurement, but may not be able to completely evaporate the solvent in the diluted resist solution. In that case, the dry film thickness may be calculated using an algorithm from the graph of FIG.

  The film thickness measurement data obtained by the film thickness measuring device 85 measured in this way is sent to the controller 90 and further sent to the process controller 92, and it is judged whether or not it is within a predetermined film thickness range (step 5).

  If it is determined that the predetermined range is reached, the valve 75c is closed and the valve 75a is opened, whereby the diluted resist is supplied to the resist solution supply mechanism, and the diluted resist solution is discharged from the resist solution discharge nozzle 14 and the substrate. A resist solution is applied onto G (step 6). In this step 6, first, the diluted resist solution is supplied to one of the buffer tanks 71a and 71b, for example, the buffer tank 71a. The buffer tank 71a stores an amount of diluted resist solution necessary for coating one substrate (for example, 80 mL). By opening the valve 76a and driving the pump 74, the buffer tank 71a includes The diluted resist solution is supplied to the resist solution discharge nozzle 14 via the pipes 72a and 73, and is used for applying the resist solution to the actual substrate G. In addition, since the diluted resist solution is stored in the buffer tank 71b in preparation for the application of the next substrate, the application of the next substrate can be performed using the diluted resist solution in the buffer tank 71b. Throughput can be kept high.

  On the other hand, if it is determined in step 5 that the film thickness is out of the predetermined film thickness range, a command is output from the process controller 92 to the high concentration resist solution pump 63 and the solvent pump 66 via the controller 90 to output the high concentration resist. The ratio of liquid to solvent is changed (step 7).

  The high-concentration resist solution and the solvent are supplied to the mixing unit 70 at a changed ratio, mixed by the merging block 67 and the static mixer 68 of the mixing unit 70, and the above steps are performed on the diluted resist solution whose ratio is readjusted. The circulation to the circulation line 3 and the monitor application and the film thickness measurement in step 4 are performed, and the determination in step 5 is made again. Usually, it is adjusted to a predetermined concentration by one retry.

  In the above concentration adjustment, the film thickness measurement can be performed in a short period of about 5 seconds, and even if a retry is made, it can be completed in a short period of time, so if the coating process on one substrate is about 1 minute. The concentration can be adjusted during the conventional substrate coating process. Therefore, density adjustment can be performed for each substrate. Of course, the density adjustment may be performed for each lot.

  In this way, the concentration of the resist solution is adjusted in-line, and the diluted resist solution is prepared by providing a circulation line in the piping for supplying the resist solution to the resist solution discharge nozzle, performing the monitor coating, and measuring the film thickness. The mixing ratio can be grasped and the mixing ratio can be appropriately controlled based on the result, so that the waste of the resist solution can be eliminated. Moreover, since the concentration of the resist solution used for the next coating can be adjusted during the coating of the resist solution, the throughput is not reduced.

  When the resist solution in the buffer tank 71a or 71b does not have a predetermined concentration, the valve 76a or 76b is closed and the valve 83a or 83b is opened, and the circulation pump 84 circulates it through the return pipe 82. Can be.

  Next, an example of conditions for actually performing in-line resist solution concentration adjustment and monitoring film thickness measurement will be described. The capacity of the monitor application pump 80 is 6 mL, the capacity of the circulation pump 84 is 10 mL, the inner diameter of the pipe is 4.35 mm, and the application time for one substrate is 1 minute in consideration of the retry of film thickness measurement. Assume that measurement is performed twice, and measurement is possible in 5 seconds in the film thickness measuring device. When the capacity between the monitor buffer tank 77 and the monitor application discharge nozzle is 19.5 mL, the replacement amount is about three times, so the capacity of the monitor buffer tank 77 is 60 mL. Further, if the volume of the static mixer 68 is 7.5 mL and the piping volume of the circulation line is 7.4 mL, the amount that must be circulated by the circulation pump 84 is 10 mL of the circulation pump 84 and the monitor buffer tank 77. Considering the capacity of 60 mL, 7.5 + 60 + 10 + 7.4 = 84.9 mL. As described above, when the film thickness is measured twice in one minute and the correction amount supply time from the pump 63 or 66 is assumed to be 3 seconds, the time that can be actually circulated by the circulation pump 84 is 1 minute- ( 5 seconds + 3 seconds) × 2 = 44 seconds. If the reload time and the discharge time are considered to be the same, it is necessary to circulate twice in 44 seconds. Therefore, 84.9 mL calculated above in 44 seconds ÷ 2 ÷ 2 = 11 seconds must be dispensed. Therefore, the discharge rate of the circulation pump 84 is 84.9 ÷ 11 = 7.7 mL / second, and converted to a flow rate of 519 mm / second. The above assumption is based on realistic conditions, and the resulting flow rate of the circulation pump 84 is 519 mm / second, which is also a realistic numerical value. It was confirmed that this was sufficiently feasible.

  The present invention can be variously modified without being limited to the above embodiment. For example, in the above-described embodiment, an example of scan coating in which a resist solution is supplied from a long resist supply nozzle while moving the substrate in one direction has been described. However, the present invention is not limited thereto, and the nozzle is moved, for example. Needless to say, the present invention can be applied to both scan application and spin application.

  Further, although the film thickness of the coating film is used as a parameter that serves as an index of the blending ratio of the high-concentration resist solution and the solvent, the present invention is not limited to this, and other parameters may be used. Furthermore, although the case where a resist solution is used as the coating solution has been shown, the present invention can be applied to other coating solutions such as a coating solution used for polyimide or a dielectric film. Furthermore, although an example in which a glass substrate for LCD is used as a substrate has been shown, it goes without saying that the present invention can also be applied to other substrates such as a semiconductor wafer.

12; Stage 13; Substrate transport mechanism 14; Resist liquid discharge nozzle 23a; Resist coating device (CT)
61; High concentration resist solution tank 62, 65; Pipe 63; High concentration resist solution pump 64; Solvent tank 66; Solvent pump 67; Merge block 68; Static mixer 69; Diluted resist feed pipe 69c; Part 71a, 71b; buffer tank 74; resist solution supply pump 75a, 75b, 75c; valve (switching mechanism)
76; Three-way valve 77; Monitor buffer tank 78; Monitor pipe 79; Monitor application discharge nozzle 80; Monitor application pump 82; Return pipe 82c; Circulation pipe 84; Circulation pump 85; Film thickness measuring device 90; Controller 92; Process controller 94; Storage unit 100; Resist coating / development processing system 101; Belts 102 and 103; Roller 106; Vacuum drying device 110; Heater G; Glass substrate for LCD

Claims (17)

A high-concentration coating liquid delivery section for delivering a high-concentration coating liquid;
A solvent delivery section for delivering the solvent;
The high-concentration coating solution delivery unit and the solvent delivery unit are connected to a pipe, and a mixing unit that mixes the high-concentration coating solution and the solvent to form a diluted coating solution diluted to a predetermined concentration;
A coating liquid discharge mechanism for discharging the diluted coating liquid to form a coating film on the substrate;
A diluted application liquid supply pipe for supplying the diluted application liquid from the mixing unit toward the application liquid discharge mechanism;
A diluted coating solution having a buffer tank for temporarily storing the diluted coating solution from the diluted coating solution supply pipe and a supply pump for supplying the diluted coating solution from the buffer tank to the coating solution discharge mechanism A supply mechanism;
A diluted coating solution that is connected to each of the buffer tank and the diluted coating solution feed pipe, takes the diluted coating solution from either the buffer tank or the diluted coating solution feed pipe, and circulates it back to the mixing unit. The circulation part,
A first switching mechanism that switches a destination of the diluted coating liquid between the coating liquid discharge mechanism side and the diluted coating liquid circulation unit side;
A coating treatment apparatus comprising: The first switching mechanism includes:
A first on-off valve for the supply and cutoff of the diluent application liquid from the diluent application liquid feed pipe to the diluted coating liquid circulating unit,
A second switching valve for supplying and interrupting said diluting the coating solution from the diluted coating liquid feed pipeline to the diluted coating solution discharge mechanism,
The coating treatment apparatus according to claim 1, comprising: The dilute coating liquid circulation unit further includes a monitor coating mechanism that discharges the diluted coating liquid and performs monitor coating on an object to be coated;
3. The diluted coating solution circulation unit takes in the diluted coating solution from the diluted coating solution supply pipe to the monitor coating mechanism and returns it to the mixing unit for circulation. Coating treatment equipment. The monitoring application mechanism includes a monitor application ejection nozzles for performing monitoring coating said the member to be coated by ejecting the dilute coating solution, monitor for temporarily storing said diluted coating solution from the diluted coating liquid feed pipe with a use buffer tank, and a monitoring application pump for supplying the diluted coating liquid from the monitor buffer tank to the monitoring application ejection nozzle,
The diluted coating liquid circulating unit, before Symbol monitor buffer tank takes in the dilution coating liquid, the coating apparatus according to claim 3, wherein the benzalkonium is circulated back to the mixing unit. A film thickness measuring device for measuring the thickness of the coating film applied by the monitor coating mechanism;
When it is determined whether the mixing ratio of the high-concentration coating liquid and the solvent is within a predetermined range from the result of film thickness measurement by the film thickness measuring device, and when it is determined that the mixing ratio is not within the predetermined range, Adjusting the mixing ratio of the high-concentration coating liquid delivered from the high-concentration coating liquid delivery part and the solvent delivered from the solvent delivery part, leaving the diluted coating liquid delivery destination as the diluted coating liquid circulation part A control mechanism that, when the mixing ratio is within a predetermined range, operates the first switching mechanism to control the dilute coating liquid delivery destination to be the coating liquid discharge mechanism side; The coating processing apparatus according to claim 4, comprising: a coating processing apparatus according to claim 4. 6. The coating liquid processing apparatus according to claim 4, wherein a capacity of the monitoring buffer tank is smaller than a capacity of the buffer tank. A second switching mechanism for switching the supply destination of the diluted coating liquid from the buffer tank between the coating liquid discharge mechanism and the diluted coating liquid circulating unit;
A third switching mechanism for switching the supply destination of the diluted application liquid from the monitor buffer tank between the monitor application discharge nozzle and the diluted application liquid circulation unit;
The coating liquid processing apparatus according to claim 4, further comprising: The second switching mechanism includes:
A third on-off valve for supplying and shutting off the diluted coating solution from the buffer tank to the diluted coating solution circulation unit;
A fourth on-off valve for supplying and blocking diluted coating liquid from the buffer tank to the coating liquid discharge mechanism;
The third switching mechanism includes:
A fifth on-off valve for supplying and shutting off the diluted coating solution from the monitoring buffer tank to the diluted coating solution circulation unit;
A sixth on-off valve for supplying and shutting off the diluted coating solution from the monitor buffer tank to the monitor coating discharge nozzle;
The coating processing apparatus according to claim 7 , further comprising: Before SL member to be coated is a roller coating apparatus according to any one of claims 8 from claim 4, characterized in that the monitoring applied while rotating the roller. Before SL member to be coated is a substrate for monitoring, according to claim 4, characterized in that the monitoring application on the monitoring substrate while causing relative movement between said monitoring application ejection nozzle and the monitoring substrate The coating treatment apparatus according to claim 8 . Before SL member to be coated is a belt wound around a plurality of transport rollers, the coating process according to any one of claims 8 from claim 4, characterized in that the monitoring applied while moving the belt apparatus. Discharging dilution coating solution from the previous SL monitoring application ejection nozzle, the coating apparatus according to claim 11, characterized in that it is carried out at just above one of the transport rollers over. The film thickness measuring apparatus, the coating apparatus according to claim 11 or claim 12, characterized in that it is arranged to perform directly a film thickness measurement of one of the transport rollers over. The mixing unit, the high concentration coating solution and a merging block is merged in a turbulent state of the solvent, claim from claim 1, characterized in that it comprises a static mixer provided downstream of the junction block 13 The coating treatment apparatus according to any one of the above. The coating liquid discharge mechanism has a slit corresponding to the width of the substrate, and discharges the diluted coating liquid while performing a relative linear motion in a state of being kept at a constant interval from the substrate. coating treatment device according to any one of claims 14 claim 1. The coating processing apparatus according to claim 1 , wherein the buffer tank stores a diluted coating solution corresponding to one substrate. The coating processing apparatus according to claim 16 , wherein the diluted coating liquid supply mechanism has two buffer tanks, and one of the two buffer tanks is connected to the coating liquid discharge mechanism side.

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