JP5658349B2 - Substrate processing apparatus and chemical supply method - Google Patents

Description

  The present invention relates to a substrate processing apparatus and a chemical solution supply method.

  In a photolithography process that is indispensable for manufacturing a semiconductor device or a flat panel display (FPD), various defects may occur due to a material used in this process. For example, a chemical solution such as a resist solution or an organic solvent contains fine particles, or in particular a chemical solution containing a polymer dispersoid, which solidifies (or gels) locally in the chemical solution over time. May occur, and these may cause defects. In order to reduce such defects, the chemical liquid is supplied to the dispense nozzle of the spin coater after being filtered by a filter (see, for example, Patent Documents 1 and 2).

JP 62-204877 A JP 2008-305980 A

  Here, some examples of the chemical solution supply system will be described with reference to FIG. FIG. 1 (a) is a schematic view of a chemical solution supply system used by the present inventors and particularly suitable for supplying a solvent. As shown in the figure, this chemical supply system 101 includes a liquid end tank LE that temporarily stores the solvent supplied from the canister tank CT, a filter F that filters the solvent, and a solvent stored in the liquid end tank LE. A pump Pa supplied to the filter F and a flow meter FM for measuring the flow rate of the chemical liquid passing through the filter F are configured. In addition, the liquid end tank LE, the pump Pa, and the filter F are provided with a vent valve V, whereby the dissolved air dissolved in the solvent is degassed. The chemical solution supply system 101 configured as described above is disposed, for example, in or near the resist coating device or the development processing device in the coating and developing system, and the solvent cleaned by the chemical solution supplying system 101 is used as the resist coating device. And the supply of the solvent from the dispensing nozzle DN is controlled by opening and closing the valve C. In FIG. 1, the wafer held below the dispense nozzle DN is omitted.

  FIG. 1B is a schematic view of a chemical solution supply system 102 suitable for supplying a resist solution. As illustrated, the chemical solution supply system 102 includes a liquid end tank LE, a filter F, a trap T, a pump Pb, and an out trap OT. Compared with the chemical solution supply system 101 for the solvent in FIG. 1A, the difference is that a filter F is disposed between the liquid end tank LE and the pump Pb. A trap T is disposed between the filter F and the pump Pb. The trap T is used to remove relatively large bubbles that cannot be removed only by the vent valve V provided in the filter F. For example, since a relatively large amount of air remains in the filter F after the replacement of the filter F, a large amount of air is discharged from the filter F together with the resist solution immediately after the replacement. This air is easily released into the atmosphere by the trap T. The out trap OT provided downstream of the pump Pb is similarly used to remove air that may remain in the pump Pb.

  FIG. 1C is a schematic view of another chemical solution supply system 103 suitable for supplying a resist solution. In this chemical solution supply system 103, a feed pump FP is provided upstream of the filter F, and a dispense pump DP is provided downstream. The feed pump FP pushes the resist solution toward the filter F, and the dispense pump DP pulls the resist solution from the filter F. Thereby, it becomes possible to perform filtration at a constant speed without applying a large pressure (stress) to the resist solution. In the chemical solution supply system 103, a vent valve VP and a feed pump FP provided in the dispense pump DP are connected. As a result, bubbles in the resist solution that reach the dispense pump DP without being removed by the vent valve V provided in the filter F are returned to the feed pump FP and can be removed by the vent valve V of the filter F. For this reason, unlike the chemical solution supply system 102 shown in FIG. 1B, the trap T and the out trap OT are not provided.

  Next, how the chemical solution supply system provides the chemical solution to the resist coating apparatus will be described using the chemical solution supply system 102 shown in FIG. 1B as an example.

  First, a predetermined amount of resist solution is supplied from the resist bottle B to the liquid end tank LE and stored in the liquid end tank LE. Next, in the resist coating apparatus, when the opening / closing valve C1 provided on the upstream side of the dispensing nozzle DN is opened, the resist solution pressurized by the pump Pb of the chemical solution supply system 102 is discharged onto the wafer from the dispensing nozzle DN. . At the same time, the same amount of resist solution as that supplied on the wafer is sucked (absorbed) from the liquid end tank LE by the pump Pb. At this time, the resist solution passes through the filter F, and impurities and the like contained in the resist solution are filtered. Thus, the discharge to the wafer, the liquid absorption that supplements the discharged resist liquid, and the filtration that accompanies the liquid absorption form one cycle.

  In order to increase the filtration effect by the filter F in such a chemical solution supply system, it is preferable to reduce the speed at which the resist solution passes through the filter F (filtration rate). As a result, it takes time to discharge the resist solution onto the wafer, and the throughput of the resist coating apparatus decreases. Moreover, if the filter F with a small eye size (pore size) is used in order to increase the filtration effect, the filtration rate cannot be increased, leading to a decrease in throughput. There is also a problem that the usable filter F is limited.

  On the other hand, in order to increase the throughput, it is only necessary to perform liquid absorption and filtration in a short time, so it is conceivable to use a filter having a relatively large filtration surface. However, the chemical solution does not always pass through the entire filtration surface, and passes through a low pressure portion, so the passage rate cannot always be increased. Further, it is considered that providing two chemical supply systems for the resist coating apparatus can increase the throughput, but there is a possibility that the resist liquid cannot be discharged with good reproducibility due to individual differences such as pumps.

  The present invention has been made in light of the above circumstances, and can improve the filtration effect without reducing the throughput.

  According to the first aspect of the present invention, there is provided a substrate processing apparatus including a chemical solution supply unit that supplies a chemical solution onto a substrate, and a chemical solution supply system that supplies the chemical solution from a chemical supply source to the chemical solution supply unit. Connects the first container connected to the chemical liquid supply source via the inlet pipe, the second container connected to the chemical liquid supply section via the outlet pipe, and the first container and the second container. A first pump provided in the first pipe and flowing the chemical stored in the first container to the second container, and provided in the first pipe, from the first container toward the second container. There is provided a substrate processing apparatus including a first filter that filters a chemical solution flowing in a first pipe, and a second pipe that connects the first container and the second container.

  According to the second aspect of the present invention, there is provided a chemical liquid supply method for supplying a chemical liquid from a chemical liquid supply source onto a substrate via a chemical liquid supply unit by the chemical liquid supply system, the chemical liquid supply system entering the chemical liquid supply source. A first container connected via a pipe, a second container connected via an outlet pipe to the chemical supply section, and a first pipe connecting the first container and the second container. The first pump for flowing the chemical solution stored in the first container to the second container and the first pipe, and flows in the first pipe from the first container toward the second container. A first filter for filtering the chemical solution, and a second pipe connecting the first container and the second container, and the on-off valve provided in the outlet pipe is opened to supply the chemical liquid from the second container A discharging step, and a filtering step of operating the first pump and filtering the chemical solution with the first filter; Chemical supplying method characterized by comprising is provided.

  According to the embodiment of the present invention, the filtration effect can be enhanced without reducing the throughput.

It is the schematic of the chemical | medical solution supply system utilized by the present inventors in the process which completes this invention. 1 is a plan view showing a coating and developing system according to an embodiment of the present invention. FIG. 2 is a perspective view of the coating and developing system of FIG. 1. FIG. 2 is a perspective view showing a processing unit block in the coating and developing system of FIG. 1. FIG. 2 is a side view of the coating and developing system of FIG. 1. It is the schematic which shows the coating unit with which the coating and developing system by embodiment of this invention is equipped. It is the schematic which shows the chemical | medical solution supply system by embodiment of this invention. It is a time chart for demonstrating operation | movement of the chemical | medical solution supply system of FIG. 7 compared with operation | movement of the chemical | medical solution supply system shown in FIG.1 (b). It is the schematic which shows the chemical | medical solution supply system by the modification of embodiment of this invention.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. In the following description, the same or corresponding parts or members are denoted by the same or corresponding reference numerals, and redundant description is omitted.

  FIG. 2 is a plan view showing the coating and developing system according to the present embodiment. As shown in the figure, the coating and developing system 1 includes a carrier block S1 for carrying in and out a wafer carrier 20 capable of accommodating, for example, 13 semiconductor wafers (hereinafter referred to as wafers) W, processing unit groups B and U1, shelf units U2, and so on. U3 and a processing block S2 in which the main arm A is disposed, and an interface block S3 disposed between the processing block S2 and the exposure apparatus S4.

  In the carrier block S 1, a mounting table 21 on which a plurality of wafer carriers 20 can be mounted, an opening / closing unit 22 provided on a wall behind the mounting table 21, and a wafer W is taken out from the wafer carrier 20 through the opening / closing unit 22. A transfer arm C that accommodates the wafer carrier 20 is provided. The transfer arm C is movable up and down and rotatable about a vertical axis so that the wafer W can be transferred between the wafer carrier 20 and a shelf unit U2 of the processing block S2 described later. It is configured to be movable in the direction (X-axis direction) and to be extendable and retractable in the direction of the wafer carrier 20 (Y-axis direction).

  The processing block S2 is connected to the back surface of the carrier block S1 (the surface opposite to the wall on which the opening / closing part 22 is provided). The processing block S2 includes a processing device group B including various processing units, a shelf block U2 arranged on the carrier block S1 side in the processing block S2, and a shelf block U3 arranged on the interface block S3 side in the processing block S2. A main arm A configured to be movable between the shelf blocks U2 and U3, and a processing device group U1 including various processing units in the same manner as the processing device group B are disposed.

  As shown in FIG. 3, the processing device group B includes five unit blocks B1 to B5 stacked. Each unit block B1 to B5 can have, for example, a resist coating unit, a development processing unit, a heating unit, a hydrophobization processing unit, a cooling unit, and the like. For example, the unit blocks B1 and B2 are exposed to a post-exposure heating unit that heats the wafer W after the resist film is exposed, a cooling unit that adjusts the wafer W heated by the post-exposure heating unit to a predetermined temperature, and the unit blocks B1 and B2. It is possible to have a processing unit such as a development processing unit for developing the resist film and a baking unit for heating the developed wafer W for drying. On the other hand, the unit blocks B3 to B5 can have a coating unit to be described later. For example, referring to FIG. 4, a coating unit 50 is provided in the unit block B3. In the coating unit 50, a resist solution is dropped on the wafer W, and the wafer W is rotated to form a resist film. In the coating unit 50, the antireflection film can also be formed by dropping a chemical solution for the antireflection film on the wafer W and rotating the wafer W.

  As shown in FIG. 5, the processing unit group U1 is disposed so as to face the unit block B3 via a movable area of a transfer arm A3 described later. As illustrated, the processing apparatus group U1 includes various processing units such as cooling units COL31 to COL33, heating units CHP31 to CHP33, a hydrophobic processing unit ADH, and a peripheral exposure unit WEE in the present embodiment. Thereby, before forming the antireflection film in the antireflection film coating unit 50B of the unit block B3, for example, the wafer W is adjusted to a predetermined temperature by the cooling unit COL31, or the wafer W on which the antireflection film is formed, for example. Can be heated in the heating unit CHP31. In addition, before applying the resist solution onto the wafer W, it is possible to perform a hydrophobic treatment in the hydrophobic treatment unit ADH in order to improve the adhesion between the resist solution and the wafer W. Further, only the peripheral edge of the wafer W may be selectively exposed by the peripheral exposure unit WEE before the wafer W on which the resist film is formed is transferred to the exposure apparatus S4.

  Note that the transfer of the wafer W between each processing unit of the processing unit group U1 and the coating unit 50 of the unit block B3 is performed by a transfer arm A3 provided corresponding to the unit block B3 as shown in FIG. Is called. The transfer arm A3 includes two forks 61 and 62 that can hold the wafer W, and is movable along a rail 65 that extends in the Y-axis direction. Thus, the main arm A includes the transfer arms A1 to A5 provided corresponding to the unit blocks B1 to B5 (see FIG. 5). Similarly to the transfer arm A3, the transfer arms A1, A2, A4, A5 also have two forks and are movable along the Y-axis direction.

  Further, a processing device group having the same configuration as the processing device group U1 may be provided for the unit blocks B4 and B5.

  Referring to FIG. 5, the shelf unit U2 includes stages TRS1 to TRS5 provided corresponding to the unit blocks B1 to B5. For example, two stages TRS1 are provided corresponding to the unit block B1, and each stage TRS1 is disposed so as to be accessible by the transfer arm A1 of the unit block B1, and holds the wafer W loaded by the transfer arm A1. Can do. Thereby, for example, the wafer W processed by the processing unit of the unit unit B1 is taken out from the processing unit by the transfer arm A1, and is carried and held in one of the two stages TRS1. The wafer W held by the stage TRS1 is accommodated in the wafer carrier 20 by the transfer arm C of the carrier block S1, for example. In addition, as shown in FIG. 2, the transfer arm D1 is provided adjacent to the shelf unit U2. The transfer arm D1 is configured to be movable back and forth and up and down. Thereby, the wafer W can be delivered between the stages TRS1 to TRS5 of the shelf unit U2.

  Further, the shelf unit U2 is provided with a stage TRS-F. The stage TRS-F is mainly used for temporarily holding the wafer W taken out from the wafer carrier 20 by the transfer arm C of the carrier block S1.

  The shelf unit U3 includes stages TRS6 to TRS10 provided corresponding to the unit blocks B1 to B5. For example, the shelf unit U3 is provided with two stages TRS10 corresponding to the unit block B5, and each stage TRS10 is disposed so as to be accessible by the transfer arm A5 of the unit block B5, and is loaded by the transfer arm A5. The wafer W can be held. Thereby, for example, the wafer W processed by the processing unit of the unit unit B5 is taken out from the processing unit by the transfer arm A5, and is carried and held in one of the two stages TRS10. The wafer W held by the stage TRS10 is taken out by, for example, an interface arm E (described later) of the interface block S3 and is carried out to the exposure apparatus S4 (FIG. 2). As shown in FIG. 2, a transfer arm D2 is provided adjacent to the shelf unit U3. The transfer arm D2 is configured to be movable back and forth and up and down, whereby the wafer W can be transferred between the stages TRS5 to TRS10 of the shelf unit U3.

  Referring to FIG. 2 again, the interface block S3 is connected to the opposite side of the processing block S2 from the carrier block S1. The interface block S3 includes an interface arm E for delivering the wafer W to the shelf unit U3 and the exposure apparatus S4 of the processing block S2, and a buffer 83 having a plurality of shelves that respectively hold a plurality of wafers W. including. The interface arm E functions as a transfer mechanism for the wafer W between the processing block S2 and the exposure apparatus S4. In the present embodiment, the interface arm E is configured to be movable up and down, rotatable about the vertical axis, and advanced and retracted in the X-axis direction, whereby the stages TRS6 to TRS10 of the shelf unit U3 corresponding to the unit blocks B1 to B5. And wafers W are transferred between the shelves of the buffer 83.

  The buffer 83 temporarily stores, for example, the wafer W on which a resist film is formed when adjusting the throughput between the exposure apparatus S4 and the processing block S2 or when changing the exposure conditions. It is suitably used when sequentially transporting to S4. In this way, the processing in the processing block S2 can be matched to the processing speed of the exposure apparatus S4, and exposure processing can be performed by appropriately changing the exposure intensity, reticle, etc. for each lot.

  Next, for example, the coating unit 50 provided in the unit block B3 of the processing apparatus group B will be described. Referring to FIG. 6A, the coating unit 50 includes a chuck 51 that holds the center of the back surface of the wafer W by suction, a motor 52 that rotates the chuck 51 via a rotating shaft 51a coupled to the chuck 51, and A dispenser 56 that drops a chemical solution such as a resist solution onto the wafer W held by the chuck 51 and a cup portion 53 that has a concave shape and is provided so as to surround the wafer W held by the chuck 51. .

  The cup portion 53 includes an upper cup 53U, a bottom cup 53B, and a cup base 53E. The upper cup 53U is arranged at the upper end of the bottom cup 53B so that the chemical liquid dropped from the dispenser 56 onto the wafer W and blown off from the wafer W by rotation can be received. A waste liquid pipe 54a is connected to the bottom of the bottom cup 53B, and the chemical liquid that has flowed down to the bottom cup 53B is discharged from the cup section 53 through the waste liquid pipe 54a. A plurality of exhaust pipes 54b are connected to the bottom of the bottom cup 53B, and the exhaust pipe 54b is connected to an exhaust unit (not shown). The exhaust unit may be, for example, an exhaust processing facility provided in a clean room where the resist coating and developing system 1 is installed. Thereby, the air in the cup part 53 is exhausted through the exhaust pipe 54b, and the organic solvent evaporating from the chemical solution such as the resist solution dropped on the wafer W is exhausted. That is, cross contamination due to an organic solvent or the like in the resist coating and developing system 1 can be reduced by exhausting through the exhaust pipe 54b.

  As shown in FIG. 6B, the dispenser 56 has an arm portion 56a attached to the guide rail 565 via a base portion 56b, and a resist nozzle 56R and a solvent nozzle 56L provided at the tip of the arm portion 56a. doing. The base portion 56b can be slid along the guide rail 565 by a drive mechanism (not shown), so that the arm portion 56a can be positioned above the wafer W and positioned outside the upper cup 53U. can do.

  One end of a conduit 56t is connected to the resist nozzle 56R, and the other end of the conduit 56t is connected to the chemical solution supply system 57 according to the embodiment of the present invention via an open / close valve 58 outside the coating unit 50. The conduit 56t is flexible so as not to hinder the movement of the dispenser 56, and may be, for example, a vinyl tube. With such a configuration, when the arm portion 56a moves along the guide rail 565, the resist nozzle 56R is positioned almost above the center of the wafer W, and the opening / closing valve 58 is opened, the resist solution is supplied from the chemical solution supply system 57. It is discharged onto the wafer W.

  The solvent nozzle 56L is provided to wet the surface of the wafer W with a solvent (for so-called pre-wetting) prior to the discharge of the resist solution from the resist nozzle 56R. Although not shown, the solvent nozzle 56L is connected to the chemical solution supply system according to the embodiment of the present invention via an open / close valve by a conduit similarly to the resist nozzle 56R. This chemical solution supply system is configured to supply a solvent, for example, thinner. As a result, when the arm portion 56a moves along the guide rail 565, the solvent nozzle 56L is positioned almost above the center of the wafer W, and the open / close valve is opened, the thinner is discharged from the chemical supply system 57 onto the wafer W. Is done. Thereafter, when the wafer W is rotated by the chuck 51 at a predetermined rotation speed for a predetermined period, the surface of the wafer W can be wetted with the solvent.

  Further, in the coating unit 50, as shown in FIG. 6B, after the resist film is formed on the wafer W, the rinsing liquid is applied to the edge portion in order to remove the resist film formed on the edge portion of the wafer W. An EBR (Edge Bead Removal) dispenser 55 is provided. The EBR dispenser 55 is attached to a base portion 55 b that is slidably provided on the guide rail 565. Moreover, although illustration is abbreviate | omitted, the EBR dispenser 55 is connected to the chemical | medical solution supply system by embodiment of this invention via the on-off valve by the conduit | pipe. This chemical solution supply system is configured to supply a rinse solution. After the resist film is formed on the wafer W held by the chuck 51, the arm portion 55a of the EBR dispenser 55 moves along the guide rail 565 while the wafer W is rotated by the chuck 51, and the EBR dispenser 55 When the opening / closing valve is opened above the edge portion of the wafer W, the rinsing liquid is discharged from the chemical solution supply system to the edge portion. Thereby, the resist film on the edge portion of the wafer W is removed.

  The development processing unit disposed in the processing block S2 of the coating and developing system 1 is the same as the coating unit 50 except that the developing solution is discharged from the resist nozzle 56R or the solvent nozzle 56L of the dispenser 56. You may have a configuration. In such a development processing unit, a wafer having a resist film formed on the wafer in the coating unit 50 and exposed in the exposure apparatus is held by the chuck 51, and a developer is discharged from the dispenser 56 to the wafer. The exposed resist film is developed.

  Hereinafter, the chemical supply system 57 according to the embodiment of the present invention will be described with reference to FIG. As illustrated, the chemical liquid supply system 57 includes an inlet tank 71, a primary pump 73, a filter 74, a secondary pump 75, an outlet tank 76, a return pipe 77, and a return pump 78.

  The inlet tank 71 is connected to a resist bottle (not shown) by a pipe IL, and stores a resist solution supplied from the resist bottle through the pipe IL. One end of a pipe 72 is connected to the inlet tank 71, and the other end of the pipe 72 is connected to an outlet tank 76.

  A primary pump 73, a filter 74, and a secondary pump 75 are provided in this order from the inlet tank 71 to the outlet tank 76 in the pipe 72. The resist solution stored in the inlet tank 71 is pushed out to the filter 74 by the primary pump 73, and the resist solution that passes through the filter 74 and is filtered by the filter 74 is sucked by the secondary pump 75 and supplied to the outlet tank 76. Is done. Therefore, the exit tank 76 stores the resist solution filtered and cleaned by the filter 74.

  One end of the outlet pipe OL is connected to the outlet tank 76, and the other end of the outlet pipe OL is connected to an open / close valve 58 (see FIG. 6B) provided in the coating unit 50. The cleaned resist solution stored in the outlet tank 76 is supplied to the coating unit 50 through the outlet pipe OL. One end of a return pipe 77 is connected to the outlet tank 76, and the other end of the return pipe 77 is connected to the inlet tank 71. As a result, the inlet tank 71 and the outlet tank 76 communicate with each other through the return pipe 77. A return pump 78 is provided in the return pipe 77, and the cleaned resist solution stored in the outlet tank 76 can be returned to the inlet tank 71 by the return pump 78.

  A bypass pipe 73a is provided in parallel with the primary pump 73. By opening a stop valve (not shown) provided in the bypass pipe 73a, the resist solution from the inlet tank 71 passes to the filter 74 through the bypass pipe 73a. Flowing. Depending on the resist solution and the filter F to be used, the filter 74 can be passed through the resist solution without applying excessive stress even by the secondary pump 75 alone. In such a case, it is preferable to use the bypass pipe 73a without using the primary pump 73. In this case, the primary tank 73 and the bypass pipe 73a are not provided in the pipe 72, and the inlet tank 71 and the filter 74 may be directly connected.

  Similarly, the secondary pump 75 is also provided with a bypass pipe 75a, and the use / non-use of the secondary pump 75 can be selected by opening / closing a stop valve (not shown). If the resist solution can be supplied to the outlet tank 76 only by the primary pump 73 without sucking the resist solution from the filter 74 by the secondary pump 75, the bypass pipe 75a is used without using the secondary pump 75. preferable. In this case, neither the secondary pump 75 nor the bypass pipe 75a may be provided in the pipe 72, and the filter 54 and the outlet tank 76 may be directly connected.

  In addition, the inlet tank 71, the filter 74, and the outlet tank 76 are provided with a vent line VL (the vent valve is not shown), thereby releasing bubbles contained in the resist solution. The vent line VL is connected to an exhaust facility provided in the clean room, and after a predetermined detoxification process is performed on the gas released from the vent line VL, the vent line VL is released to the atmosphere.

  Next, how the chemical supply system 57 according to the present embodiment provides a resist solution to the resist coating apparatus will be described. In the chemical solution supply system 57, a predetermined amount of resist solution stored in the inlet tank 71 passes through the filter 74 by the primary pump 73 and the secondary pump 75, is filtered, and is stored in the outlet tank 76. When the resist nozzle 56R of the dispenser 56 is positioned almost above the center of the wafer W and the opening / closing valve 58 provided in the coating unit 50 is opened, the resist solution stored in the outlet tank 76 is supplied to the dispenser 56 through the outlet pipe OL. Then, it is discharged onto the wafer W from the resist nozzle 56R. On the other hand, the resist solution stored in the outlet tank 76 is returned to the inlet tank 71 through the return pipe 77 by the return pump 78. The resist solution returned to the inlet tank 71 is temporarily stored in the inlet tank 71 together with the resist solution supplied from the resist bottle. However, the resist solution passes through the filter 74 by the primary pump 73 and the secondary pump 75 and is filtered. It is possible to return to the outlet tank 76 again. That is, the resist solution can be circulated in the order of the inlet tank 71, the primary pump 73, the filter 74, the secondary pump 75, the outlet tank 76, and the return pump 78 through the pipe 72 and the return pipe 77, and passes through the filter 74. It is filtered every time. Such a recirculation is performed independently of the supply of the resist solution stored in the outlet tank 76 to the coating unit 50.

In addition, since a certain amount of resist solution purified by filtration is stored in the outlet tank 76, and the resist solution is supplied from here to the coating unit 50, the same amount of resist solution discharged onto the wafer W is used. The timing at which the resist solution is sucked into the outlet tank 76 does not have to be matched with the discharge timing. (Even if the resist solution in the outlet tank 76 is reduced by the discharge, the resist solution necessary for the next discharge remains in the outlet tank 76.)
That is, it becomes possible to independently perform discharge of the resist solution onto the wafer W, absorption of the resist solution into the outlet tank 76, and filtration by the filter 74. Therefore, by performing the above reflux at a relatively slow speed (by reducing the filtration rate), it is possible to increase the throughput by increasing the discharge rate while maintaining a high filtration effect.

  The above operation is shown in FIG. 8 in comparison with the operation of the chemical solution supply system 102 in FIG. Referring to FIG. 8A, in the chemical solution supply system 57 according to the present embodiment, a predetermined amount of resist solution is supplied from the outlet tank 76 to the coating unit 50 and discharged from the dispenser 56 onto the wafer within a predetermined period. After (after the discharge process), the same amount of resist solution as that discharged is replenished (liquid absorption) (liquid absorption process). At this time, since excess resist solution remains in the outlet tank 76, this liquid absorption step is not performed by the liquid absorption to the outlet tank 76 but by the liquid absorption from the resist bottle (not shown) to the inlet tank 71. It may be. Since the pipe IL from the resist bottle to the inlet tank 71 is not provided with a filter, this liquid absorption process is performed in a short time. The resist solution is transferred from the inlet tank 71 to the outlet tank 76 and / or the resist solution is circulated between the inlet tank 71 and the outlet tank 76 in parallel with the discharge process and the liquid absorption process. During such transfer or recirculation, a filtration process is performed in which the resist solution is filtered by passing through the filter 74. Therefore, the resist solution supply cycle to the coating unit 50 by the chemical solution supply system 57 need only include a discharge process and a relatively short-time liquid absorption process, and can be repeated in a short period of time. For this reason, for example, the resist solution is supplied in synchronism with a cycle of loading of the wafer in the coating unit 50, pre-wetting of the surface of the wafer W, coating of the resist solution, rotation of the wafer, EBR (Edge Bead Removal) process, and unloading of the wafer. It becomes possible.

  On the other hand, referring to FIG. 8B, in the chemical solution supply system 102 of FIG. 1B, a predetermined amount of resist solution is discharged onto the wafer from the dispense nozzle DN (FIG. 1B) within a predetermined period. After the step of performing (or overlapping with the discharge step), a step of sucking the same amount of resist solution from the liquid end tank LE starts, but a filter F is provided between the liquid end tank LE and the pump Pb. Therefore, it takes time for the resist solution to pass through the filter F. For this reason, as shown in FIG.8 (b), the process of liquid absorption and filtration takes time longer than a discharge process. Therefore, for example, it is difficult to synchronize with a cycle that can be realized in the coating unit 50, and it may be necessary to provide a standby period for synchronization. In the illustrated example, according to the chemical liquid supply system 57 according to the present embodiment, only one discharge process is performed in the chemical liquid supply system 102 of FIG. 1B during the period in which the two discharge processes are performed. From the above description, the advantages and effects of the chemical solution supply system 57 according to the embodiment of the present invention are understood.

  Further, since the resist solution can be circulated between the inlet tank 71 and the outlet tank 76, the filtered resist solution is not stored in the outlet tank 76 for a long time. Even if it is filtered once, if it is stored in the outlet tank 76 for a long time, the resist solution deteriorates in the outlet tank 76 and the resist component may be polymerized, which may cause defects. Therefore, the cause of such a defect can be eliminated. Further, since the resist solution does not stay in the filter 74 for a long time due to the recirculation of the resist solution, clogging of the filter 74 can be suppressed. As a result, the life of the filter 74 can be extended, and the frequency of maintenance can also be reduced. Therefore, it is possible to improve the throughput by reducing the downtime of the chemical solution supply system 57.

  Further, according to the chemical supply system 57 according to the present embodiment, the liquid absorption process, the filtration process, and the discharge process can be controlled independently, so that the filtration rate, the return amount from the outlet tank 76 to the inlet tank 71, the discharge amount, etc. It can be set independently, so that flexible processing in the coating unit 50 is possible.

Next, a modification of the chemical solution supply system 57 according to the present embodiment will be described with reference to FIG.
(Modification 1)
FIG. 9A is a schematic diagram showing a chemical solution supply system 57A according to the first modification of the present embodiment. In this chemical solution supply system 57 </ b> A, two pipes 721 and 722 are connected between the inlet tank 71 and the outlet tank 76. The pipe 721 is provided with a primary pump 731, a filter 741, and a secondary pump 751 in this order, and the pipe 722 is provided with a primary pump 732, a filter 742, and a secondary pump 752 in this order. The primary pumps 731 and 732 are provided with bypass pipes 731a and 732a, and the secondary pumps 751 and 752 are provided with bypass pipes 751a and 752a.

  According to such a configuration, the resist solution is transferred (filtered) from the inlet tank 71 to the outlet tank 76 through the two pipes 721 and 722. Further, since the return pipe 77 and the return pump 78 are also provided in the chemical solution supply system 57 </ b> A, the resist solution is circulated between the inlet tank 71 and the outlet tank 76. Therefore, the chemical solution supply system 57A of Modification 1 also exhibits the same effect as the chemical solution supply system 57 shown in FIG. Further, in the chemical solution supply system 57A of the first modification, it is not always necessary to use the two pipes 721 and 722. For example, in the two pipes 721 and 722, the upstream of the primary pumps 731 and 732 and the secondary pumps 751 and 752 are used. A stop valve may be provided on the downstream side of one of the two pipes 721 and 722. This is suitable, for example, when the filter 742 of the pipe 722 is replaced while the pipe 721 is in use.

(Modification 2)
FIG. 9B is a schematic diagram showing a chemical liquid supply system 57B according to the second modification of the present embodiment. In the chemical solution supply system 57B, a primary pump 78a, a filter 78b, and a secondary pump 78c are provided in a return pipe 77 that connects the inlet tank 71 and the outlet tank 76. According to this, the resist solution stored in the outlet tank 76 is also filtered by the filter 78b when being returned to the inlet tank 71 by the primary pump 78a and the secondary pump 78c. Therefore, since the resist solution is filtered twice between the inlet tank 71 and the outlet tank 76, the same effect as the chemical solution supply system 57 shown in FIG. The effect can be further enhanced. Also in the chemical solution supply system 57B, a bypass pipe 78d is provided in parallel with the primary pump 78a, and a bypass pipe 78e is provided in parallel with the secondary pump 78c.

  Further, in the chemical solution supply system 57B of the second modification, not only the outlet pipe OL1 that supplies the resist solution to the coating unit 50 is connected to the outlet tank 76, but also a similar outlet pipe OL2 is connected to the inlet tank 71. Good. For example, when a predetermined amount of resist solution is supplied from a resist bottle (not shown) to the inlet tank 71 and then refluxed between the inlet tank 71 and the outlet tank 76 for a predetermined period, the resist solution stored in the inlet tank 71 Is also cleaned by filtration. Moreover, since the high filtering effect is exhibited by the two filters 74 and 78b, the resist solution stored in the inlet tank 71 can be cleaned in a relatively short time. Then, it becomes possible to supply the cleaned resist solution from the inlet tank 71 to the coating unit 50 through the outlet pipe OL2.

  Note that, instead of the return pump 78 of the chemical solution supply system 57A shown in FIG. 9A, the primary pump 78a, the filter 78b, and the secondary pump 78c shown in FIG. 9B are replaced with the chemical solution shown in FIG. 9A. You may provide in the return piping 77 of 57 A of supply systems. In this case, the outlet pipe OL2 of FIG. 9B may be provided in the inlet tank 71 of the chemical liquid supply system 57A.

  The present invention has been described above with reference to the embodiments and modifications. However, the present invention is not limited to the above-described embodiments and the like, and can be variously modified in light of the appended claims. .

  For example, in the above-described embodiment, the chemical solution supply system 57 that supplies the resist solution to the coating unit 50 has been described. However, the supplied chemical solution is not limited to the resist solution, and for example, a chemical solution for an antireflection film is supplied. In this case, the chemical solution supply system 57 can be used.

  Furthermore, the chemical solution supply system 57 according to the embodiment of the present invention may be used as a chemical solution supply system for supplying a developer to a development processing unit that develops the exposed resist film. The present invention can also be applied to a chemical solution for forming a so-called spin-on-dielectric (SOD) film such as a polyimide film or a low-k dielectric film on a wafer.

  When the chemical solution supply system according to the embodiment of the present invention is used for supplying the developer and the rinse solution, the developer solution and the rinse solution are not used from the canister tank for storing the developer and the rinse solution, but from the chemical solution supply equipment shared in the entire clean room. A rinse liquid may be supplied to the inlet tank 71.

  In particular, when supplying a rinsing solution, one chemical solution supply system 57 or the like is provided for a plurality of application units and / or development processing units, and a plurality of application units and / or from one chemical solution supply system 57 or the like. Alternatively, a rinse solution may be supplied to the development processing unit. Further, when a plurality of dispensers or dispense nozzles are provided in the coating unit and / or the development processing unit (for example, an EBR dispenser and a back rinse nozzle), rinse liquid is supplied from a single chemical solution supply system 57 to a plurality of dispensers. May be. Note that supplying chemical solutions from a single chemical supply system 57 or the like to a plurality of units or dispensers, for example, by using the same lot of chemical solution for wafers of the same lot, for example, film thickness or device between wafers This is preferable in that the uniformity of characteristics can be improved. Also, when using a chemical solution that is relatively easily deteriorated and should be used in a short period of time, it is preferable to supply the chemical solution from one chemical solution supply system 57 or the like to a plurality of units or dispensers.

  Further, the piping 72, 721, 722 and the return piping 77 may be provided with throttle valves having orifices (openings) smaller than the inner diameters of these piping. Such a throttle valve not only controls the flow rate of the chemical liquid flowing through the pipe, but also can apply a predetermined pressure to the chemical liquid. In particular, pressure is applied to the chemical at the inlet of the throttle valve, and the pressure is released when passing through the orifice. If it does so, the dissolved gas which was dissolved in the chemical | medical solution with the reduction | decrease of a pressure can be actualized. That is, the dissolved gas can be removed. Therefore, defects that can be caused by dissolved gas can be reduced.

  For example, in the chemical solution supply system 57 (FIG. 7), a throttle valve may be provided on the upstream side of the filter 74 instead of or in addition to the primary pump 73, and the secondary pump 75 may be replaced or added on the downstream side of the filter 74. A throttle valve may be provided. A throttle valve may be arranged on the upstream side or the downstream side of the return pump 78. When the throttle valve is replaced with the primary pump 73, the throttle valve can adjust the pressure on the inlet side of the filter 74, and the filtration effect of the filter 74 can be maintained constant, for example. When the throttle valve is replaced with the secondary pump 75, the throttle valve can adjust the pressure on the outlet side of the filter 74, and the filtration effect of the filter 74 can be maintained constant, for example. Further, if a throttle valve is provided on the upstream side of the return pump 78, the dissolved gas is positively revealed by decompressing the chemical solution before the return pump 78, and a vent valve (not shown) provided in the return pump 78 is shown. It is possible to release dissolved gas from Further, if a throttle valve is provided on the downstream side of the return pump 78, the dissolved gas is positively revealed by decompressing the chemical solution before the inlet tank 71, and dissolved from the vent line VL provided in the inlet tank 71. Gas can be released. A pipe IL (FIG. 7) throttle valve that connects the inlet tank 71 and a resist bottle or a canister tank (not shown) may be provided. Further, a vent valve may be combined with the throttle valve.

  Further, in the chemical solution supply system 57A (FIG. 9A), a throttle valve may be provided on the upstream side of the filter 741 (or 742) instead of or in addition to the primary pump 731 (or 732), and the filter 741 (or 742) may be provided with a throttle valve instead of or in addition to the secondary pump 751 (or 752). A throttle valve may be arranged on the upstream side or the downstream side of the return pump 78.

  Further, in the chemical solution supply system 57B (FIG. 9B), a throttle valve may be provided in place of or in addition to the primary pump 73 on the upstream side of the filter 74, and the secondary pump 75 is provided on the downstream side of the filter 74. A throttle valve may be provided instead of or in addition. In addition, a throttle valve may be arranged upstream or downstream of the primary pump 78a (FIG. 9B) of the return pipe 77, and the secondary pump 78c of the return pipe 77 (FIG. 9B). A throttle valve may be arranged on the upstream side or downstream side of the valve.

  In the chemical solution supply system 57A of the first modification, filters having different eye sizes (pore sizes) may be used as the filters 741 and 742. Further, in the chemical solution supply system 57B of Modification 2, a filter having a small eye size is used as the filter 74 provided in the pipe 72, and a filter having a relatively large eye size is used as the filter 78b provided in the return pipe 77. May be used. Conversely, the size of the filter 78b provided in the return pipe 77 may be made smaller.

  In addition, as the primary pump 73 and the like and the secondary pump 75 and the like, any of a pneumatic pump, a mechanical pump, and a pump with a flow rate control function may be used. Pneumatic pumps have a constant shearing stress applied to the chemical solution. For example, when using resist solution or anti-reflective coating chemical solution, fluctuations in the solvent mixing ratio can be suppressed, and dissolved gas can be reduced. It is preferable in that it can be performed. Further, if a pump with a flow rate control function is used, for example, if the discharge amount at the start of the pump is gradually increased, it is possible to suppress a sudden pressure from being applied to the filter 74 and the like. it can. For example, when the chemical solution supply system 57 or the like and the coating unit 50 are started from the idle state, if the chemical solution suddenly flows to the filter 74 or the like and a sudden pressure is applied to the filter 74 or the like, impurities can pass through the filter 74 or the like. There is sex. Therefore, it is preferable to use a pump with a flow rate control function and avoid applying a sudden pressure to the filter 74 or the like. In this case, it is more preferable to use a pump with a flow rate control function as the primary pump 73 or the like.

  Further, pressure sensors may be provided on the upstream side and the downstream side of the filter 74 and the like. According to this, it becomes easy to grasp the replacement time of the filter 74 and the like by monitoring the differential pressure.

  The capacities of the inlet tank 71 and the outlet tank 76 may be appropriately determined depending on the number of wafers (one lot) to be processed. Note that another pressure sensor may be provided instead of or in addition to the pressure sensor for measuring the differential pressure such as the filter 74. The position is preferably on the downstream side of the primary pump 73, for example. Thereby, the pressure applied to the chemical solution can be monitored, and the dissolved gas due to the application of pressure can be reduced. Moreover, you may provide the flowmeter which measures the flow volume of the chemical | medical solution which flows through piping 72 (721,722) in piping 72 (721,722). According to this, based on the measured flow rate value, it becomes possible to prepare a cleaned chemical solution, for example, according to the amount of the chemical solution used in the coating unit 50 or the like. Such a flow meter may be provided in the return pipe 77.

  In addition, if the pressure sensor, the flow meter, and the pump with a flow rate control function are used in appropriate combination, the flow of the chemical solution in the chemical solution supply systems 57, 57A, and 57B can be further optimally controlled and cleaned. It becomes possible to supply a chemical solution with little dissolved gas to the coating unit.

  In the chemical solution supply system 57 shown in FIG. 7, a branch pipe that separates the pipe 72 into a plurality of branch pipes may be provided on the downstream side of the primary pump 73 of the pipe 72, and a filter 74 may be provided in each of the branch pipes. In this case, it goes without saying that a branch pipe for joining the branch pipes is provided on the upstream side of the secondary pump 75. Further, a stop valve may be provided in each branch pipe, and one or more filters of the plurality of filters 74 may be selected and used.

  In addition, the chemical solution supply system according to the embodiment of the present invention is not only used for supplying the chemical solution to the coating unit and the development processing unit, but can also be applied to a cleaning apparatus for cleaning a wafer. Further, the present invention can be used not only for a coating unit and a development processing unit for processing a semiconductor wafer but also for processing a glass substrate for FPD.

  DESCRIPTION OF SYMBOLS 1 ... Coating development system, S1 ... Carrier block, S2 ... Processing block, S3 ... Interface block, S4 ... Exposure apparatus, B, U1 ... Processing device group, U2, U3. ..Shelf block, 50 ... coating unit, 51 ... chuck, 52 ... motor, 53 ... cup part, 55 ... EBR dispenser, 56 ... dispenser, 57 ... chemical solution supply System: 71 ... Inlet tank, 73 ... Primary pump, 74 ... Filter, 75 ... Secondary pump, 76 ... Outlet tank, 77 ... Return piping, 78 ... Return pump , OL ... outlet piping.

Claims (9)

A substrate processing apparatus having a chemical solution supply unit that supplies a chemical solution onto a substrate, and a chemical solution supply system that supplies a chemical solution from a chemical supply source to the chemical solution supply unit,
The chemical solution supply system includes:
A first container connected to the chemical liquid supply source via an inlet pipe;
A second container connected to the chemical liquid supply unit via an outlet pipe;
A first pump that is provided in a first pipe connecting the first container and the second container, and causes a chemical solution stored in the first container to flow to the second container;
A first filter that is provided in the first pipe and filters the chemical flowing in the first pipe from the first container toward the second container;
A second pipe connecting the first container and the second container;
A substrate processing apparatus comprising:   The substrate processing apparatus according to claim 1, further comprising a second filter provided in the second pipe. The first container further includes an outlet pipe for supplying a chemical solution to the chemical solution supply unit.
The substrate processing apparatus according to claim 1 or 2.   4. The apparatus according to claim 1, further comprising a throttle valve provided in at least one of the first pipe and the second pipe and having an orifice smaller than an inner diameter of the first pipe and the second pipe. The substrate processing apparatus according to claim 1. A chemical supply method for supplying a chemical from a chemical supply source onto a substrate via a chemical supply unit by a chemical supply system,
The chemical solution supply system includes:
A first container connected to the chemical liquid supply source via an inlet pipe;
A second container connected to the chemical liquid supply unit via an outlet pipe;
A first pump that is provided in a first pipe connecting the first container and the second container, and causes a chemical solution stored in the first container to flow to the second container;
A first filter that is provided in the first pipe and filters the chemical flowing in the first pipe from the first container toward the second container;
A second pipe connecting the first container and the second container;
With
A discharge step of opening the on-off valve provided in the outlet pipe and supplying the chemical from the second container;
A filtration step of operating the first pump and filtering the chemical solution by the first filter;
A chemical solution supply method comprising:   The chemical solution supply method according to claim 5, wherein the discharge rate of the discharge step and the filtration rate of the filtration step are controlled independently. In the filtration step,
The chemical solution according to claim 5 or 6, wherein the chemical solution is filtered a plurality of times while the chemical solution is circulated in the order of the first container, the first pipe, the second container, and the second pipe. Supply method.   The chemical solution supply method according to any one of claims 5 to 7, wherein the filtration step further includes a step of revealing and removing dissolved gas dissolved in the chemical solution. A chemical supply method for supplying a chemical from a chemical supply source onto a substrate via a chemical supply unit by a chemical supply system,
The chemical solution supply system includes:
A first container connected to the chemical liquid supply source via an inlet pipe;
A second container connected to the chemical liquid supply unit via an outlet pipe;
A first pump that is provided in a first pipe connecting the first container and the second container, and causes a chemical solution stored in the first container to flow to the second container;
A first filter that is provided in the first pipe and filters the chemical flowing in the first pipe from the first container toward the second container;
A second pipe connecting the first container and the second container;
With
A discharge step of opening the on-off valve provided in the outlet pipe and supplying the chemical from the second container;
A refluxing step of refluxing the chemical solution in the order of the first container, the first pipe, the second container, and the second pipe;
Including
The chemical solution supply method, wherein the discharge step and the reflux step are performed independently.

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