Processing liquid supply device and processing liquid supply method

Abstract

To improve cleanliness of a processing liquid while suppressing consumption of the processing liquid to be supplied to a discharge portion of the processing liquid to a substrate.SOLUTION: A processing liquid supply device that supplies a processing liquid to a discharge portion that discharges a processing liquid onto a substrate includes a supply line connected to the discharge portion, a first pump that is interposed in the supply line and pressure-feeds the processing liquid to the discharge portion, a first on-off valve interposed upstream of the first pump, a filter that filters the processing liquid, a second on-off valve interposed downstream of the first pump in the supply line, a return line in which one end is branched from between the first pump and the filter in the supply line and the second on-off valve, and the other end is connected to the downstream side of the first on-off valve in the supply line and the upstream side of the first pump and filter, a second pump interposed in the return line and pumping the processing liquid toward one end of the return line, a third on-off valve interposed between one end of the return line and the second pump, and a fourth on-off valve interposed between the other end of the return line and the second pump.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a treatment liquid supplying apparatus and a treatment liquid supplying method. [Background technology]

[0002] Patent Document 1 discloses a resist liquid supply device including a processing liquid container for storing resist liquid, a nozzle for discharging the resist liquid onto a wafer, and a resist liquid supply path consisting of piping connecting the processing liquid container and the nozzle. The resist liquid supply path includes, in this order from upstream, a buffer tank for temporarily storing the resist liquid from the processing liquid container, a filter for filtering the resist liquid to remove foreign matter, a pump, a flow rate regulator, an operation valve, and a suck-back valve. The resist liquid is discharged by opening the air-operated valve and operating the pump, which moves the resist liquid in the buffer tank from the processing liquid container downstream through the resist liquid supply path. Therefore, the resist liquid is discharged from the nozzle at a flow rate set by, for example, the flow rate regulator. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-139665 Summary of the Invention [Problem to be solved by the invention]

[0004] The technology according to the present disclosure improves the cleanliness of the processing liquid while suppressing the consumption of the processing liquid supplied to a portion that discharges the processing liquid onto a substrate. [Means for solving the problem]

[0005] One aspect of the present disclosure is a processing liquid supply device that supplies a processing liquid to a discharge part that discharges the processing liquid onto a substrate, the processing liquid supply device including: a supply pipe line connected to the discharge part; The processing liquid is delivered at a constant flow rate and pressure.the treatment liquid is supplied to the supply pipe line upstream of the first pump; a first on-off valve disposed in the supply pipe line upstream of the first pump; a filter disposed in the supply pipe line to filter the treatment liquid; a second on-off valve disposed in the supply pipe line downstream of the first pump; a return pipe line having one end branched off from between the first pump and the filter and the second on-off valve in the supply pipe line and having the other end connected to the supply pipe line downstream of the first on-off valve and upstream of the first pump and the filter; a second pump disposed in the return pipe line and pressure-feeding the treatment liquid toward the one end of the return pipe line; a third on-off valve disposed in the return pipe line between the one end and the second pump; and a fourth on-off valve disposed in the return pipe line between the other end and the second pump. [Effects of the Invention]

[0006] According to the present disclosure, it is possible to improve the cleanliness of the processing liquid supplied to a portion that discharges the processing liquid onto a substrate while suppressing consumption of the processing liquid. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is an explanatory diagram illustrating an outline of the configuration of a processing liquid supply device according to an embodiment of the present invention; [Figure 2] 10A and 10B are diagrams illustrating a state of the treatment liquid supply device during a circulating discharge operation. [Figure 3] 10A and 10B are diagrams illustrating a state of the treatment liquid supply device during a discharge operation. [Figure 4] FIG. 10 is a diagram showing a state of the processing liquid supply device during a refilling operation. DETAILED DESCRIPTION OF THE INVENTION

[0008] In the photolithography process in the manufacturing process of semiconductor devices, etc., a series of processes is performed to form a predetermined resist pattern on a substrate such as a semiconductor wafer (hereinafter referred to as "wafer"). The series of processes includes, for example, a resist coating process in which a resist solution is supplied onto the substrate to form a resist film, an exposure process in which the resist film is exposed to light, and a development process in which a developer is supplied to the exposed resist film and developed.

[0009] Processing liquids such as resist liquid and developer liquid are discharged onto the substrate through a discharge nozzle. A filter is installed in the supply pipe connected to the discharge nozzle to remove minute foreign matter (particles) from the processing liquid.

[0010] However, even if a filter is provided as described above, if the processing liquid remains in the supply pipeline, foreign matter may be included in the processing liquid discharged onto the substrate, which may be detected as a defect. To avoid this, there is a method of periodically discharging the processing liquid in the supply pipeline from a discharge nozzle, etc., but this method consumes a large amount of processing liquid due to the amount of discharge, and there is room for improvement in terms of cost.

[0011] Therefore, the technology according to the present disclosure improves the cleanliness of the processing liquid while suppressing the consumption of the processing liquid supplied to the discharge portion of the processing liquid onto the substrate.

[0012] Hereinafter, a processing liquid supplying apparatus and a processing liquid supplying method according to the present embodiment will be described with reference to the drawings. In this specification and the drawings, elements having substantially the same functional configurations are designated by the same reference numerals, and redundant description will be omitted.

[0013] FIG. 1 is an explanatory diagram showing an outline of the configuration of a processing liquid supplying device according to this embodiment. The processing liquid supply device 100 in Fig. 1 supplies a processing liquid to a discharge nozzle as a discharge unit. In this embodiment, the processing liquid supply device 100 supplies a processing liquid to a plurality of (four in the illustrated example) discharge nozzles 1a to 1d. In other words, the processing liquid supply device 100 is common to the plurality of discharge nozzles 1a to 1d. However, the number of discharge nozzles to which the processing liquid supply device 100 supplies may be one.

[0014] In the following description, among the components of the processing liquid supplying apparatus 100, those having common functions, such as the discharge nozzles 1a to 1d, will be described with the alphabetical characters omitted as appropriate. For example, the "discharge nozzles 1a to 1d" will be described as "discharge nozzle 1" as appropriate.

[0015] Each of the discharge nozzles 1a to 1d discharges a processing liquid onto a wafer W (an example of a substrate) on a corresponding holding unit, that is, a spin chuck 2. The processing liquid supplied by the processing liquid supply device 100 and discharged by the discharge nozzles 1a to 1d is, for example, a resist liquid.

[0016] The processing liquid supply device 100 includes supply pipes 150a to 150d connected to the discharge nozzles 1a to 1d. The supply pipes 150 are provided for each discharge nozzle 1, and for example, a downstream end of the supply pipe 150 is connected to the discharge nozzle 1, and an upstream end of the supply pipe 150 is connected to a resist liquid bottle 101. The supply pipelines 150a to 150d join together on their upstream sides to form a main supply pipeline 151. Furthermore, the supply pipelines 150a to 150d branch off from the main supply pipeline 151 on their upstream sides to form branch supply pipelines 152a and 152b, and resist solution bottles 101a and 101b are connected to the upstream ends of the branch supply pipelines 152a and 152b, respectively.

[0017] The resist liquid bottle 101 is a liquid supply source that stores resist liquid therein and is replaceable. In this embodiment, a plurality of resist liquid bottles 101 (specifically, two) are provided, so that even while one resist liquid bottle 101 is being replaced, resist liquid can be supplied from another resist liquid bottle 101. Open / close valves V1a and V1b are provided in branch supply pipes 152a and 152b connected to the resist liquid bottles 101a and 101b.

[0018] Gas supply lines 200a and 200b, in which on-off valves V2a and V2b are installed, are also connected to the resist solution bottles 101a and 101b. The gas supply lines 200a and 200b connect gas supply sources 110a and 110b, which are sources of inert gas such as nitrogen gas, to the resist solution bottles 101a and 101b, and electropneumatic regulators 111a and 111b for adjusting pressure are provided upstream of the on-off valves V2a and V2b.

[0019] In this embodiment, the first pump 102 and the resist solution bottle 101 are directly connected, and no intermediate container such as a buffer tank is provided between them. Therefore, foreign matter generated from the inner wall of the storage chamber of the intermediate container does not get mixed into the resist solution sucked into the first pump 102.

[0020] The supply pipes 150a to 150d are provided with a first pump 102, a filter 103, and a flow meter 104. In this embodiment, the first pump 102, the filter 103, and the flow meter 104 are common to the supply pipes 150, and are provided in the main supply pipe 151. The first pump 102, the filter 103, and the flow meter 104 are provided, for example, in this order from the upstream side.

[0021] A first on-off valve V11 is provided in the supply pipes 150a to 150d upstream of the first pump 102. In this embodiment, the first on-off valve V11 is also common to the supply pipes 150, and is provided in the main supply pipe 151 upstream of the first pump 102.

[0022] Furthermore, second on-off valves V12a to V12d are provided in the supply pipes 150a to 150d downstream of the first pump 102. In this embodiment, the second on-off valve V12 is provided for each supply pipe 150, that is, for each discharge nozzle 1. Moreover, the second on-off valve V12 is integrated with the discharge nozzle 1. This makes it possible to prevent the resist solution from accumulating in the pipe connecting the second on-off valve V12 and the discharge nozzle 1, thereby preventing a decrease in cleanliness.

[0023] The first pump 102 is configured to simultaneously suck in and deliver resist liquid, and is, for example, a magnetically levitated centrifugal pump. The first pump 102 sucks in resist liquid from a resist liquid bottle 101 or the like, and pressure-feeds the resist liquid to a discharge nozzle 1 or the like. This first pump 102 can constantly deliver resist liquid at a constant flow rate and constant pressure. Note that "simultaneously sucking in and delivering resist liquid" specifically means that the operation of sucking in resist liquid and the operation of delivering resist liquid are performed without mechanical switching.

[0024] The filter 103 filters the resist liquid to remove particles. Specifically, the filter 103 filters the resist liquid sent out from the first pump 102 to remove particles in the resist liquid.

[0025] The processing liquid supplying apparatus 100 also includes return pipes 160a to 160d. The return pipe 160 is provided for each supply pipe 150, that is, for each discharge nozzle 1. One end of the return pipe 160 branches off from between the first pump 102 and the filter 103 and the second on-off valve V12 in the supply pipe 150. Specifically, one end of the return pipe 160 branches off from the corresponding supply pipe 150 downstream of the main supply pipe 151 and upstream of the second on-off valve V12. On the other hand, the other end of the return pipe 160 is connected to the supply pipe 150 downstream of the first on-off valve V11 and upstream of the first pump 102 and the filter 103. Specifically, the other end of the return pipe 160 is connected to the main supply pipe 151 between the first on-off valve V11 and the first pump 102 and the filter 103.

[0026] Therefore, the return pipes 160 constitute a circulation path for the resist liquid together with a portion of the supply pipes 150. Specifically, each of the return pipes 160 constitutes a circulation path for the resist liquid together with a corresponding portion of the supply pipes 150. The "portion of the supply pipes 150" refers to the portion of the supply pipes 150 that includes the first pump 102 and the filter 103.

[0027] Furthermore, the return pipes 160a to 160d join at the other ends to form a main return pipe 161. Further, the return pipes 160a to 160d are provided with a second pump 105. In this embodiment, the second pump 105 is common to the return pipes 160 and is provided in the main return pipe 161.

[0028] Flow meters 106a to 106d and third on-off valves V13a to V13d are provided between the second pump 105 and the one ends of the return pipes 160a to 160d. In this embodiment, the flow meter 106 and the third on-off valve V13 are provided for each return pipe 160, i.e., for each discharge nozzle 1. The flow meter 106 and the third on-off valve V13 are provided in this order from the main return pipe 161 side.

[0029] Furthermore, a fourth on-off valve V14 is interposed between the other ends of the return pipes 160a to 160d and the second pump 105. In this embodiment, the fourth on-off valve V14 is common to the return pipes 160 and is interposed in the main return pipe 161.

[0030] The second pump 105 is configured to be able to pump the resist liquid at least toward the one end of the return pipe 160, i.e., at least toward the discharge nozzle 1. In this embodiment, when the resist liquid flows from the one end of the return pipe 160 to the other end by being pumped from the first pump 102, i.e., when the resist liquid circulates through a circulation path including the return pipe 160, the second pump 105 does not pump the resist liquid but serves as a simple pipe. Therefore, the second pump 105 is configured by, for example, a diaphragm pump.

[0031] In this embodiment, an on-off valve V15 is provided in the main supply pipe 151 between the first pump 102 and the filter 103.

[0032] The processing liquid supplying apparatus 100 further includes a control unit M. The control unit M is, for example, a computer equipped with a CPU, a memory, and the like, and has a program storage unit (not shown). The program storage unit stores a program for controlling the processing in the processing liquid supplying apparatus 100. The program may be recorded on a computer-readable storage medium H and installed from the storage medium H into the control unit M. The storage medium H may be temporary or non-temporary. Some or all of the program may be realized by dedicated hardware (circuit board).

[0033] Each valve provided in the processing liquid supplying apparatus 100 is an electromagnetic valve or an air-operated valve that can be controlled by a control unit M, and each valve is electrically connected to the control unit M. The control unit M is also electrically connected to the first pump 102 and the second pump 105. With this configuration, a series of processes in the processing liquid supplying apparatus 100 can be performed automatically under the control of the control unit M. The control unit M is further connected to each flow meter, so that the control unit M can perform control based on the measurement results of the flow meter.

[0034] <Operation of the Processing Liquid Supply Apparatus 100> Next, the operation of the processing liquid supply device 100 will be described with reference to Figures 2 to 4. Figures 2 to 4 are diagrams showing the states of the processing liquid supply device 100 during circulation, discharge, and replenishment, respectively. In Figures 2 to 4, valves in the open state are shown in white, valves in the closed state are shown in black, and pipes through which the resist liquid or inert gas flows are shown in bold lines, and descriptions of the open and closed states of other valves will be omitted as appropriate. Note that before each of the circulation and discharge operations, the supply pipe 150 and the return pipe 160 are assumed to be filled with the resist liquid in advance. Furthermore, each of the following operations is performed under the control of the control unit M.

[0035] <circulation> In the processing liquid supply device 100, when the resist liquid is not supplied to any of the discharge nozzles 1, that is, when the resist liquid is not being discharged from any of the discharge nozzles 1, the resist liquid is circulated in a circulation path including the return pipe 160 so that the resist liquid does not stagnate in the supply pipe 150. Specifically, as shown in Fig. 2, the first on-off valve V11 and all of the second on-off valves V12 are closed, and the on-off valve V15, all of the third on-off valves V13, and the fourth on-off valve V14 are open. Then, the second pump is not driven, and the first pump 102 is driven.

[0036] As a result, the first pump 102 simultaneously sucks in and pumps out the resist liquid, and the resist liquid circulates through a circulation path including the return pipe 160 and a portion of the supply pipe 150 while being filtered by the filter 103. Specifically, the resist liquid circulates through a circulation path including the return pipe 160a and a portion of the supply pipe 150a, a circulation path including the return pipe 160b and a portion of the supply pipe 150b, a circulation path including the return pipe 160c and a portion of the supply pipe 150c, and a circulation path including the return pipe 160d and a portion of the supply pipe 150d while being filtered by the filter 103.

[0037] During circulation, the first pump 102 pumps out the resist liquid so that the measurement result of the flow meter 104 becomes a desired value. Also, during circulation, the opening of the corresponding third on-off valve V13 may be adjusted to adjust the flow rate of the resist liquid in each return pipe line 160 so that the measurement result of each flow meter 106 becomes a desired value. During circulation, the resist liquid also passes through the second pump 105, but the second pump is not activated and serves as a conduit through which the resist liquid flows.

[0038] The above-described circulation is also performed when starting up the processing liquid supply apparatus 100. In this case, the above-described circulation is performed so that the resist liquid is filtered by the filter 103 multiple times.

[0039] By circulating the resist liquid in this manner, it is possible to prevent particles adhering to the filter 103 and the like from being mixed into the resist liquid due to stagnation.

[0040] <Discharge> In the processing liquid supply device 100, for example, the resist liquid is supplied to only one of the multiple discharge nozzles 1a to 1d, and the resist liquid is discharged from that one nozzle. During discharge from the discharge nozzle 1a, for example, the on-off valves V1a and V2a are opened, as shown in Fig. 3. Also, the first on-off valve V11, the on-off valve V15, and the second on-off valve V12a corresponding to the discharge nozzle 1a are opened, and the second on-off valves V12b to V12d corresponding to the other discharge nozzles 1b to 1d that are not the target of the resist liquid supply are closed. In this state, the inside of the resist liquid bottle 101a is pressurized with inert gas from the gas supply source 110a, and the first pump 102 is driven. As a result, the resist liquid that has been sent from the first pump 102 and filled in the supply pipe 150a corresponding to the discharge nozzle 1a and that has passed through the filter 103 is supplied to the discharge nozzle 1a.

[0041] Furthermore, the third on-off valve V13a corresponding to the discharge nozzle 1a is opened, and the third on-off valves V13b to V13d and the fourth on-off valve V14 corresponding to the other discharge nozzles 1b to 1d that are not the target of the resist liquid supply are closed. Then, the second pump 105 is driven. As a result, the resist liquid that has been sent from the second pump 105 and filled in the return pipe 160a corresponding to the discharge nozzle 1a is supplied to the discharge nozzle 1a. In other words, the resist liquid flows in a direction opposite to that during the above-mentioned circulation, and is supplied to the discharge nozzle 1a via the return pipe 160a.

[0042] Therefore, when the resist liquid is discharged from the discharge nozzle 1a, the resist liquid discharged from the first pump 102 and the resist liquid discharged from the second pump 105 toward the above-mentioned one end of the return pipe 160a are mixed and supplied to the discharge nozzle 1a. The resist liquid in the return pipe 160 has also passed through the filter 103 .

[0043] The third on-off valve V13 corresponding to the discharge nozzle 1 to which the resist liquid is to be supplied may be opened first, and then the corresponding second on-off valve V12 may be opened. This makes it possible to stabilize the discharge pressure of the resist liquid from the discharge nozzle 1.

[0044] Incidentally, the filter 103 has an appropriate range for the flow rate of the resist liquid passing through the filter 103. For example, if the flow rate of the resist liquid passing through the filter 103 is too low, particles in the resist liquid may be partially retained in the filter 103. Also, if the flow rate of the resist liquid passing through the filter 103 is high, particles adhering to the membrane of the filter 103 or the like may be mixed into the resist liquid.

[0045] In this regard, in this embodiment, when the resist solution is discharged from the discharge nozzle 1a, the first pump 102, which is configured from a magnetic levitation type centrifugal pump or the like, pumps out the resist solution so that the measurement result of the flow meter 104 becomes a desired value. Therefore, it is possible to prevent the cleanliness of the resist solution from decreasing.

[0046] It is also preferable that the flow rate of the resist liquid passing through the filter 103 is constant. This is because if the flow rate of the resist liquid passing through the filter 103 is not stable, the membrane of the filter 103 will move during the passage of the liquid, causing foreign matter to be generated from the membrane.

[0047] In this regard, in this embodiment, the first pump 102 is configured by, for example, a magnetically levitated centrifugal pump, and simultaneously sucks in and sends out the resist liquid when it is discharged from the discharge nozzle 1a.

[0048] Here, consider a case where the first pump 102, unlike the present embodiment, is configured as a single diaphragm pump and is unable to simultaneously suck and discharge the resist liquid. In this case, the first diaphragm pump discharges the resist liquid without suctioning it. Specifically, when discharging from the discharge nozzle 1a, the diaphragm pump displaces the resist liquid from the storage chamber formed by the diaphragm by deforming the storage chamber to reduce its volume without suctioning the resist liquid into it. However, in this method, in order to achieve a desired flow rate of the resist liquid, the pressure of the resist liquid (specifically, the pressure applied to the diaphragm) must be changed depending on the amount of resist liquid in the storage chamber. Therefore, if the first pump 102, unlike the present embodiment, is configured as a single diaphragm pump and is unable to simultaneously suck and discharge the resist liquid, the resist liquid cannot be discharged at a desired flow rate and constant pressure.

[0049] In contrast, in this embodiment, as described above, the first pump 102 can simultaneously suck in and discharge the resist liquid when discharging from the discharge nozzle 1a, so there is no need to change the pressure of the resist liquid in order to discharge the resist liquid at the desired flow rate. Therefore, in this embodiment, when the resist liquid is discharged from the discharge nozzle 1a, the first pump 102 can deliver the resist liquid at a desired flow rate and at a constant pressure. That is, the flow rate of the resist liquid passing through the filter 103 can be set to a desired value, while the pressure of the resist liquid can be kept constant. Therefore, the cleanliness of the resist liquid can be further improved.

[0050] However, if the resist liquid is pumped from the first pump 102 at a flow rate suitable for the filter 103, the amount of liquid discharged from the discharge nozzle 1a per given time may become insufficient. In this regard, in this embodiment, when the resist solution is discharged from the discharge nozzle 1a, not only the first pump 102 but also the second pump 105 is supplied, and the resist solution that flows backward through the circulation path including the return pipe 160a corresponding to the discharge nozzle 1a is supplied to the discharge nozzle 1a as an auxiliary. Therefore, even if the resist solution is discharged from the first pump 102 at a flow rate suitable for the filter 103, the amount of the resist solution discharged from the discharge nozzle 1a per predetermined time will not be insufficient.

[0051] When the resist solution is discharged from the discharge nozzle 1a, the second pump 105 sends out the resist solution so that the measurement result of the flow meter 106a corresponding to the discharge nozzle 1a becomes a desired value, that is, a set value. The set flow rate of the resist liquid delivered from the second pump 105 (i.e., the target value of the measurement result by the flow meter 106a) may be determined for each discharge nozzle 1. This allows the discharge amount from the discharge nozzle 1 per predetermined time to be set to a desired value, for example, to be equalized between the discharge nozzles 1, regardless of the installation state of the processing liquid supply device 100 (e.g., the distance from the discharge nozzle 1 of the supply destination to the second pump 105, the height position of the discharge nozzle of the supply destination, etc.).

[0052] <Replenishment> In the processing liquid supply apparatus 100, after the resist liquid is discharged from the discharge nozzle 1, the second pump 105 is replenished with the resist liquid. Specifically, as shown in Fig. 4, for example, the on-off valves V1a and V2a are opened. Also, the first on-off valve V11, the on-off valve V15, and one of the third on-off valves V13 are opened, and the other third on-off valve V13, all of the second on-off valves V12, and the fourth on-off valve V14 are closed. In this state, the inside of the resist liquid bottle 101a is pressurized with inert gas from the gas supply source 110a, and the first pump 102 is driven without driving the second pump 105. This causes the second pump to be replenished with resist liquid. When the replenishment is completed, the circulation operation described above is carried out.

[0053] Even when refilling the second pump 105, the first pump 102 pumps out the resist liquid so that the measurement result of the flow meter 104 reaches a desired value. Therefore, even when refilling the second pump 105, the resist liquid does not remain in the filter 103.

[0054] That is, in this embodiment, the resist solution constantly passes through the filter 103 at the same flow rate during circulation, discharge from the discharge nozzle, and refilling to the second pump 105. Therefore, movement of the membrane inside the filter 103 can be suppressed. For example, when switching from a discharge operation to a refilling operation to the second pump 105, or when switching from a refilling operation to the second pump to a circulation operation, movement of the membrane inside the filter 103 can be suppressed. As a result, generation of foreign matter from the membrane can be suppressed.

[0055] <Major Effects> As described above, in this embodiment, one end of the pipe is branched from the supply pipe 150 between the first pump 102 and the filter 103 and the second on-off valve V12, and the other end of the pipe is provided with the return pipe 160, which is connected to the supply pipe 150 downstream of the first on-off valve V11 and upstream of the first pump 102 and the filter 103. Therefore, the return pipe 160 and the portion of the supply pipe 150 including the first pump 102 and the filter 103 can form a circulation path. Therefore, when the resist liquid is not being discharged from the discharge nozzle 1, the resist liquid can be circulated within the circulation path, thereby preventing the resist liquid from stagnating and thereby reducing the cleanliness of the resist liquid. Furthermore, in this embodiment, there is no need to discharge the resist liquid from the discharge nozzle 1 or the like in order to prevent the cleanliness of the resist liquid from being reduced, and therefore the consumption of the resist liquid can be reduced. In other words, according to this embodiment, the cleanliness of the resist liquid can be improved while reducing the consumption of the resist liquid. are.

[0056] In this embodiment, the first pump 102 configured to simultaneously suck in and discharge the resist liquid is disposed in the supply pipe 150. Therefore, as described above, when discharging the resist liquid from the discharge nozzle 1a, the first pump 102 can discharge the resist liquid at a desired flow rate and constant pressure. Therefore, the flow rate of the resist liquid passing through the filter 103 can be set to a desired value, while the pressure of the resist liquid can be kept constant. This further improves the cleanliness of the resist liquid.

[0057] Furthermore, in this embodiment, a second pump 105 is provided to pump the resist liquid toward the one end of the return pipe line, so that, as described above, even if the first pump 102 delivers the resist liquid at a flow rate suitable for the filter 103, the amount of the resist liquid discharged from the discharge nozzle 1 per given time will not be insufficient.

[0058] Furthermore, in this embodiment, one processing liquid supply device 100 supplies the resist liquid to a plurality of discharge nozzles 1. Therefore, the state of the resist liquid discharged from the discharge nozzles 1 can be made uniform among the discharge nozzles 1.

[0059] (Variation) In the above example, the filter 103 is provided downstream of the first pump 102 in the supply pipe 150, but it may also be provided upstream.

[0060] Furthermore, unlike the above example, the first pump 102 may be composed of a plurality of diaphragm pumps. For example, in the first pump 102, while the first diaphragm pump is discharging resist liquid, the second diaphragm pump may be discharging resist liquid to the first diaphragm pump, and during this time, the third diaphragm pump may be refilled with resist liquid, i.e., the third diaphragm pump may be sucking resist liquid. This also makes it possible to pass resist liquid through the filter 103 at a constant flow rate and constant pressure during the discharging operation, etc.

[0061] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive, and the above-described embodiments may be omitted, substituted, or modified in various ways without departing from the scope and spirit of the appended claims. [Explanation of symbols]

[0062] 1 (1a to 1d) Discharge nozzle 100 Processing liquid supply device 102 First Pump 103 Filters 105 Second Pump 150(150a~150d) Supply pipeline 160(160a~160d) Return pipe V11 First shut-off valve V12 (V12a~V12a) Second shut-off valve V13 (V13a to V13d) 3rd shut-off valve V14 (V14a to V14d) 4th shut-off valve W wafer

Claims

1. A processing liquid supply device that supplies a processing liquid to a discharge part that discharges the processing liquid onto a substrate, a supply pipe connected to the discharge portion; a first pump that is interposed in the supply pipe line, that simultaneously sucks in and delivers the treatment liquid so as to deliver the treatment liquid at a constant flow rate and a constant pressure, and that pressure-feeds the treatment liquid to the discharge portion; a first on-off valve disposed in the supply line upstream of the first pump; a filter disposed in the supply pipe line for filtering the treatment liquid; a second on-off valve disposed in the supply line downstream of the first pump; a return line having one end branched off from a portion of the supply line between the first pump and the filter and the second on-off valve, and having the other end connected to the supply line downstream of the first on-off valve and upstream of the first pump and the filter; a second pump disposed in the return pipe line and pressure-feeding the treatment liquid toward the one end of the return pipe line; a third on-off valve interposed between the one end of the return pipe and the second pump; a fourth on-off valve interposed between the other end of the return pipe and the second pump.

2. The processing liquid supply apparatus according to claim 1 , further comprising a control unit that controls the first on-off valve, the second on-off valve, the third on-off valve, the fourth on-off valve, the first pump, and the second pump.

3. 3. The processing liquid supply device according to claim 2, wherein the control unit controls the first on-off valve, the second on-off valve, the third on-off valve, the fourth on-off valve, the first pump, and the second pump so that, during discharge from the discharge unit, the processing liquid delivered from the first pump and the processing liquid delivered from the second pump toward the one end of the return pipe are mixed and supplied to the discharge unit.

4. 4. The processing liquid supplying apparatus according to claim 3, wherein the control unit opens the third on-off valve and then the second on-off valve during discharge from the discharge unit.

5. the return pipe, together with a portion of the supply pipe including the first pump and the filter, constitutes a circulation path for the treatment liquid; 5. The processing liquid supply device according to claim 2, wherein the control unit controls the first on-off valve, the second on-off valve, the third on-off valve, the fourth on-off valve, the first pump, and the second pump so that the processing liquid circulates through the circulation path at times other than when the processing liquid is being discharged from the discharge unit.

6. supplying the treatment liquid to the plurality of discharge portions; the supply pipe line, the second on-off valve, the third on-off valve, and the return pipe line are provided for each of the discharge portions, The supply pipelines join downstream to form a main supply pipeline, The return pipes are joined at the other end to form a main return pipe, the first on-off valve, the first pump, and the filter are interposed in the main supply line; 6. The processing liquid supplying apparatus according to claim 1, wherein the second pump and the fourth on-off valve are disposed in the main return line.

7. 7. The processing liquid supply device according to claim 6, wherein each of the return pipes constitutes a circulation path for the processing liquid together with the corresponding supply pipe.

8. 8. The processing liquid supply apparatus according to claim 6, wherein when the processing liquid is discharged from one of the discharge portions, the second on-off valve and the third on-off valve for the other discharge portions are closed.

9. 9. The processing liquid supplying device according to claim 6, wherein a set flow rate of the processing liquid delivered from the second pump is determined for each of the discharge portions.

10. 10. The processing liquid supplying device according to claim 1, wherein the discharge part is integrated with the second on-off valve.

11. 1. A processing liquid supplying method for supplying a processing liquid to a discharge section that discharges the processing liquid onto a substrate using a processing liquid supplying device, The processing liquid supply device a supply pipe connected to the discharge portion; a first pump that is interposed in the supply pipe line, that simultaneously sucks in and delivers the treatment liquid so as to deliver the treatment liquid at a constant flow rate and a constant pressure, and that pressure-feeds the treatment liquid to the discharge portion; a first on-off valve disposed in the supply line upstream of the first pump; a filter disposed in the supply pipe line for filtering the treatment liquid; a second on-off valve disposed in the supply line downstream of the first pump; a return line having one end branched off from a portion of the supply line between the first pump and the filter and the second on-off valve, and having the other end connected to the supply line downstream of the first on-off valve and upstream of the first pump and the filter; a second pump disposed in the return pipe line and pressure-feeding the treatment liquid toward the one end of the return pipe line; a third on-off valve interposed between the one end of the return pipe and the second pump; a fourth on-off valve interposed between the other end of the return pipe and the second pump, the return pipe, together with a portion of the supply pipe including the first pump and the filter, constitutes a circulation path for the treatment liquid; When the treatment liquid is discharged from the discharge portion, the treatment liquid pressure-fed from the first pump and the treatment liquid pressure-fed from the second pump toward the one end of the return pipe line are mixed and supplied to the discharge portion; The treatment liquid supply method includes causing the treatment liquid pressure-fed from the first pump to pass through the second pump and circulate through the circulation path at times other than when the treatment liquid is being discharged from the discharge portion.

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