JPH10189432A - Processing liquid supply mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To supply a processing liquid to each processor from a single processing liquid supply mechanism even when a plurality of processors are provided by controlling a valve unit such that the time for delivering the processing liquid is not overlapped among the processors. SOLUTION: When a valve 160 is opened by a control signal from a controller 138, a developer in a tank 170 is passed through a flow rate regulator 168, a filter 166 and a heat-exchanger 164 associated with a transfer tube 162 and conditioned to a desired state. It is then supplied through a branch pipe and the valve 160 to a developer delivery nozzle N1 which also delivers the developer onto a wafer. In the development processor, the valve 160 is closed by a control signal from the controller 138 after a specified quantity of developer is applied onto the wafer and rotation of a spin chuck 134 is stopped.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a mechanism for supplying a processing liquid to a processing apparatus for supplying a processing liquid to a substrate to be processed and performing a predetermined processing.

[0002]

2. Description of the Related Art For example, in a so-called development process in a semiconductor manufacturing process, the following process is usually performed. First, a substrate to be processed having a resist film with a predetermined pattern exposed, for example, a semiconductor wafer (hereinafter, referred to as a semiconductor wafer)
Called "wafer". ) Is held on a rotary mounting table called a spin chuck. Next, the spin chuck is rotated, and the developer is discharged from an appropriate discharge member, for example, a nozzle, at a position above the center of the wafer.
As a result, the developing solution is uniformly diffused on the surface of the wafer by the centrifugal force and is applied, whereby a desired developing process is performed.

A mechanism for supplying the developing solution to the developing device includes, for example, a tank for storing the developing solution, a flow controller for adjusting the developing solution to a predetermined flow rate, a filter for removing impurities from the developing solution, and a developing solution. Temperature control means for adjusting the temperature to a predetermined value, a valve for supplying or stopping the developer, and the like are sequentially connected through a transfer path such as a pipe. When the valve is opened, the developer is supplied to the developing apparatus. It is configured to be. When a plurality of developing processing devices are provided, such a developing solution supply mechanism is provided independently for each device.

[0004]

However, if each developing apparatus is provided with the above-mentioned developing solution supply mechanism including a tank, the system becomes large and the manufacturing cost of the system increases. Further, when the development processing device is additionally provided, the above problem becomes more remarkable. Further, since the supply time of the developer is very short as compared with the total development processing time, the time during which the developer supply mechanism is not used is long, and the utilization efficiency is not good.

The present invention has been made in view of the above-mentioned problems of the conventional processing liquid supply mechanism. Even when a plurality of processing apparatuses are provided, the processing liquid is supplied by one processing liquid supply mechanism. It is an object of the present invention to provide a new and improved processing liquid supply mechanism capable of supplying the processing liquid to each processing apparatus.

[0006]

In order to solve the above-mentioned problems, according to the first aspect of the present invention, a processing liquid is supplied to a plurality of processing apparatuses for supplying a processing liquid to a substrate to be processed and performing a predetermined processing. A tank for storing the processing liquid, a transfer path for transferring the processing liquid from the tank to the processing apparatus side,
A branch path branching off from the transfer path and leading to the processing liquid discharge section of the processing apparatus, and a valve device interposed in each branch path to open and close the branch path are provided. The opening and closing of the processing liquid is controlled so that the time for discharging the processing liquid does not overlap.

[0007] In the control of the opening and closing of the valve device, for example, when there are two processing units, the discharge of the processing liquid in another processing unit is started after receiving the discharge end signal of the processing liquid in one processing unit. This can be performed by a configuration that starts the process or a configuration that checks whether or not the discharge of the processing liquid is performed by one processing device before the discharge of the processing liquid is started by another processing device.

According to this configuration, the discharge of the processing liquid in each processing apparatus does not overlap by the control of each valve device interposed in each branch path, so that the processing liquid is supplied to a plurality of processing apparatuses. Even in such a case, only one processing liquid supply mechanism can be used. As a result, the size of the system can be reduced and the manufacturing cost of the system can be suppressed, and the maintenance can be facilitated and the utilization efficiency can be improved.

According to a second aspect of the present invention, in the first aspect of the invention, a predetermined upper limit level and a lower limit level of the processing liquid to be stored are set in the tank, and the upper limit level and the lower limit level are set. The upper limit level and the lower limit level are set so that the amount of the processing liquid can be replenished into the tank within the time during which no processing liquid is discharged in each processing apparatus. It is characterized by:

With this configuration, the processing liquid can be replenished to the tank when the processing liquid is not supplied to any of the processing apparatuses. The processing solution can be replenished without interrupting the processing steps. As a result, the throughput can be improved. The following effects can be obtained by setting the lower limit level to an amount capable of processing at least one lot or more, that is, a backup amount or more. For example, 25 wafers stored in a cassette
In the development process in which a lot is continuously processed in each lot, if the processing for another lot is started before the processing for one lot is completed, the developer is replenished for some reason. Even if not performed, the processing can be continued with the same processing liquid for at least one lot without interrupting the processing.

Further, a third aspect of the present invention is a mechanism for supplying a processing liquid to a plurality of processing apparatuses for supplying a processing liquid to a substrate to be processed and performing a predetermined processing, and stores the processing liquid. A plurality of tanks, a transfer path for transferring the processing liquid from any of the tanks to the processing apparatus side, a switching apparatus for switching a tank that is a supply source among the tanks, and branching from the transfer path to each processing apparatus. A branch path leading to the processing liquid discharge section, and a valve device interposed in each branch path to open and close the branch path are provided, and the valve devices are arranged so that the time for discharging the processing liquid in each processing apparatus does not overlap. The opening and closing thereof are controlled, and the switching device is controlled so that the switching operation is not performed while the processing liquid is being discharged in each processing device.

According to this configuration, since the switching is performed by the switching device when the processing liquid is not being discharged in each processing apparatus, it is possible to switch to the tank storing the processing liquid without interrupting the processing step. Thus, the processing liquid can be stably supplied to each processing apparatus. Also, for example, when two tanks are provided, when the processing liquid is supplied from one tank to each processing apparatus, the processing liquid is replenished to the other tank, and after the replenishment is completed, the tank is put on standby. By doing so, the processing liquid can be supplied to the processing apparatus immediately after switching to another tank. The opening and closing of each valve device can be controlled by the same configuration as described in the first aspect of the present invention.

[0013]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
An embodiment in which the processing liquid supply mechanism according to the present invention is applied to a development processing apparatus will be described in detail. In the following description, components having substantially the same functions and configurations will be denoted by the same reference numerals, and redundant description will be omitted.

FIG. 1 shows, for example, a cleaning process for a wafer W, an adhesion process for improving the fixability of a resist, a coating process of a resist solution, an appropriate heating process performed after these processes, and a wafer W after the heating process. FIG. 1 shows an overview of a coating and developing system 100 in which various processing apparatuses that individually perform processes such as a cooling process, a developing process after exposure, and a heating process, which are individually cooled, are combined into one system. The developing solution supply mechanism according to the present embodiment is incorporated as a unit in the coating and developing system 100 as the developing devices 128 and 129.

The coating and developing system 100 includes a mounting section 102 for aligning and mounting a plurality of cassettes C, which are storage units for storing one lot of wafers W, for example, 25 wafers W, And a transfer mechanism 106 for taking out the wafer W from the cassette C placed on the unit 102 and transferring the wafer W to the main transfer arm 104. The transport mechanism 106 is movable on a transport path 108 provided along the direction in which the cassettes C are arranged. And
Various processing apparatuses for performing a predetermined process on the wafer W include:
Each transfer path 11 of the two main transfer arms 104 and 110
2, 114 are disposed on both sides.

Further, in order to clean the surface of the wafer W taken out of the cassette C, a brush cleaning device 116 for brush cleaning while rotating the wafer W, a water cleaning device 118 for high pressure jet cleaning of the wafer W, and a wafer W
Adhesion processing device 120 for improving the fixability of resist by hydrophobizing the surface of wafer W, cooling processing device 122 for cooling wafer W to a predetermined temperature, and resist liquid coating device 124 for coating resist liquid on the surface of rotating wafer W , A heating processing device 126 for heating the wafer W after the application of the resist solution or for heating the wafer W after the exposure,
Developing devices 128 and 129 for supplying a developing solution to the surface while rotating to perform a developing process are arranged. Each of these processing devices is integrated to some extent, and by grouping them into appropriate processing devices, the installation space is reduced and the processing efficiency is improved. Also,
Loading and unloading of wafers W into and from these various processing apparatuses are performed by two main transfer arms 104 and 110. Each of these processing devices and the like is disposed in the casing 130. The processing liquid supply mechanism according to the present embodiment is applied to the development processing devices 128 and 129.

Next, the developing devices 128 and 129 using the developing solution supply mechanism according to the present embodiment will be described. However, since the developing processing devices 128 and 129 have the same configuration, the developing processing device 128 will be mainly described below. As shown in FIG. 2, a spin chuck 134 that holds the wafer W in a horizontal state by vacuum is provided in a processing container 132 that stores the wafer W in a casing 128 a of the developing processing device 128. The spin chuck 134 is rotatable by a driving mechanism 136 such as a pulse motor provided below the processing container 132. The drive mechanism 136 is controlled by a controller 138 (see FIG. 3), and the controller 13
Numeral 8 counts the pulse waveform oscillated from an encoder (not shown) provided in the drive mechanism 136 for each cycle. Therefore, by setting a predetermined numerical value in the controller 138, the rotation speed of the spin chuck 134 can be arbitrarily controlled.

The atmosphere in the processing container 132 is exhausted from the center of the bottom of the processing container 132 by an exhaust means (not shown) such as a vacuum pump installed outside. Further, a developing solution serving as a processing solution and pure water serving as a rinsing solution are supplied from outside the spin chuck 134 to the processing container 132.
Through the drain pipe 140 provided at the bottom of the processing vessel 1
The liquid is discharged to a drain tank 142 installed below the nozzle 32.

In the developing device 128,
The developing solution discharged onto the wafer W is separately discharged from the developing solution discharging nozzle N1, and the rinsing liquid is discharged separately from the rinsing liquid discharging nozzle N2. The developer discharge nozzle N1 and the rinsing liquid discharge nozzle N2 are held by the corresponding nozzle holders 144 and 146, respectively.
6 is mounted on a pair of rails 148 on the side wall of the casing 128a so as to be horizontally movable. A drive mechanism (not shown) is provided in the nozzle holders 144 and 146, and the drive mechanism is controlled by a controller 138 (see FIG. 3). Therefore, the controller 13
The nozzle holders 144 and 146 are rotated by the drive signal by the control signal from
8, a predetermined parallel movement is performed.

Further, at a standby position where the developing solution discharge nozzle N1 and the rinsing solution discharging nozzle N2 stand by at a predetermined position near the side wall of the casing 128a, the developing solution discharging nozzle N1 and the rinsing solution discharging nozzle N2 are positioned below the discharge ports. Is
Discharge units 150 and 152 corresponding to each are arranged. The drains 154 and 156 are connected to the drains 150 and 152, respectively, and the drains 154 and 156 are connected to the drain tank 142.

Next, the developing solution supply mechanism according to the present embodiment, that is, the configuration for supplying the developing solution to the developing solution discharge nozzle N1 will be described. A branch pipe 158 for supplying a developer is connected to the developer discharge nozzle N1, and the branch pipe 158 is transferred via a valve 160 for supplying and stopping the developer as shown in FIG. Connected to tube 162. Further, the transfer pipe 162 is provided with a heat exchanger 164 for adjusting the developing solution to a predetermined temperature, for example, 23 ° C., a filter 166 for removing impurities mixed in the developing solution, and a flow controller 168 for adjusting the flow rate of the developing solution. Is connected to a tank 170 storing a developing solution.

The transfer pipe 162 is provided with the developing device 1
A branch pipe 172 for supplying a developing solution is connected to a developing solution discharge nozzle (not shown) 29 and a valve 17 controlled together with a valve 160 is connected to the branch pipe 172.
4 are interposed. Therefore, the development processing devices 128 and 1
29, the flow controller 168 from the tank 170 to the transfer pipe 162, the filter 166, and the like are configured to be shared. In addition, the valves 160 and 174 are configured to be opened and closed by a controller 138.

The supply pipe 17 is provided in the tank 170.
6, a developer supply source 180 for replenishing the developer into the tank 170 is connected via a valve 178. further,
A gas supply source 186 for supplying an inert gas, for example, N ₂ gas, for pressurizing the inside of the tank 170 to a predetermined pressure atmosphere via a gas supply pipe 182 and a valve 184 is connected to the tank 170. . Further, the tank 170 is connected to an evacuation mechanism 192 composed of, for example, a vacuum pump for reducing the pressure in the tank 170 to a predetermined pressure atmosphere via an exhaust pipe 188 and a valve 190.

In the tank 170, the developing device 1
The upper limit level H and the lower limit level L are set so that the amount of the developer can be replenished into the tank 170 during the time when the developer is not discharged in any of 28 and 129. Therefore, without interrupting the processing, the tank 1
The developer can be replenished in 70. Further, the lower limit level L is set to an amount capable of processing at least one lot or more, that is, a backup amount or more. Therefore, if the processing for another lot is started before the processing for one lot is completed, even if the replenishment of the developer is not performed for some reason, the processing is not interrupted and at least one processing is performed. Processing of the lot can be continued with the same processing liquid.

The main components of the developing devices 128 and 129 using the developing solution supply mechanism according to the present embodiment are configured as described above. Next, referring to FIGS.
The supply configuration of the developer to the development processing devices 128 and 129 and the supply control of the developer will be described. First, when the wafer W is placed on the spin chuck 134 in the processing container 132 of the developing device 128 shown in FIG. 2, it is suction-held by vacuum. Next, the spin chuck 134 is rotated by a control signal from the controller 138 and is maintained at a predetermined rotation speed, and the developing solution discharge nozzle N1 for supplying a predetermined developing solution is mounted on the wafer W together with the nozzle holder 144 on the predetermined position. To the discharge position.

At this time, in the tank 170 shown in FIG. 3, for example, a developer is stored up to a predetermined upper limit level H, and N ₂ gas is supplied from a gas supply source 186 to discharge under pressure. To a predetermined pressure atmosphere. When the valve 160 is opened by a control signal from the controller 138, the developer in the tank 170 passes through the flow controller 168, the filter 166, and the heat exchanger 164 interposed in the transfer pipe 162, and a desired amount of the developer flows. Is supplied to the developing solution discharge nozzle N1 through the branch pipe 158 and the valve 160, and the developing solution discharge nozzle N1
Is discharged onto the wafer W. During this time, for example, the wafer W is also transported into the developing device 129, and preparation for the developing process is performed similarly to the developing device 128. Then, in the developing processing device 128, after a predetermined amount of the developing solution is applied on the wafer W, the valve 160 is closed by the control signal from the controller 138, and the rotation of the spin chuck 134 is stopped. At the same time, the developer discharge nozzle N1 moves to a predetermined standby position.

Next, the wafer W which has been applied with the developing solution and has stopped rotating is left as it is for a predetermined time.
Development takes place. At this time, after the controller 138 confirms that the developing solution discharge process in the developing device 128 has been completed, the controller 138 controls the developing device 128 to supply the developing solution to the developing device 129 shown in FIG. The signal causes the valve 174 to open. Then, in the development processing device 128, the spin chuck 134 starts to rotate again according to the control signal from the controller 138, and at the same time, the developing solution applied to the wafer W is washed away, and a rinsing solution made of, for example, ultrapure water is discharged. The rinsing liquid discharge nozzle N2 moves to a predetermined discharge position on the wafer W together with the nozzle holder 146. Then, under the control of the controller 138, the rinsing liquid supplied from a rinsing liquid supply source (not shown) is discharged onto the wafer W from the rinsing liquid discharge nozzle N2 for a predetermined time or a predetermined amount, and the developing liquid is washed away. The rotation of the spin chuck 134 is continuously performed even after the discharge of the rinsing liquid is completed, and the rinsing liquid remaining on the wafer W is repelled by the centrifugal force, and the wafer W is dried.

After a predetermined time has elapsed, the rotation of the spin chuck 134 is stopped by the control signal of the controller 138, and the wafer W is transported for the next processing step. Next, also in the developing device 129, the developing device 12
The development processing and the developer removal processing similar to those in 8 are performed, and the developed wafer W is transported to the outside. Next, the unprocessed wafer W is transported into the developing device 128, and the same developing process as described above is performed.
The unprocessed wafer W is also transported into the inside 29 and the processing is performed.

As described above, in the developing devices 128 and 129 capable of implementing the present embodiment, the developing device 1
The discharge of the developer at 28 and the discharge of the developer at the developing device 129 are not performed at the same time, and the discharge of the developer is performed only at one of the devices. Accordingly, since the pressure atmosphere in the tank 170 is maintained at a desired pressurized state, the developer can be uniformly pressurized and discharged onto the wafer W. Further, for example, the development processing device 12
The processing in the developing device 129 is not started even if the processing in 8 does not end within a predetermined time for some reason.

Next, control of the supply of the developing solution to the developing devices 128 and 129, that is, control of opening and closing the valves 160 and 174, and control of replenishing the developing solution to the tank 170 will be described with reference to FIG. As described above, after the supply of the developing solution to the developing device 128 is completed, the developing solution is supplied to the developing device 129, and at least one lot is sequentially and alternately supplied. Therefore, as for the opening and closing of the valves 160 and 174, as shown in FIG.
The valve 174 is opened and closed, and the valve 160 is opened and closed again. However, a predetermined interval is provided after the opening and closing of the valve 160 and the opening and closing of the valve 174 until the opening and closing of the valve 160 and the opening and closing of the valve 174 next time. This interval is determined by processing steps in various processing apparatuses such as the resist liquid coating apparatus 124 and the heat processing apparatus 126, developing processing in the developing processing apparatuses 128 and 129, developing liquid removing processing, drying, and transport of the wafer W. It is inevitable.

When the developing solution is supplied to the developing devices 128 and 129, the inside of the tank 170 is pressurized to a predetermined pressure atmosphere. It is configured to be supplied to the devices 128 and 129. Therefore, in the developer supply mechanism according to the present embodiment, the developing device 12
When the developing solution is not supplied to both the tanks 8 and 129, that is, when both the valves 160 and 174 are closed, the tank 170 is replenished with the developing solution.

That is, when the valves 160 and 174 are closed, the valve 184 is closed and the gas supply source 186 is closed.
The supply of inert gas from the tank to the tank is stopped. At the same time, the evacuation mechanism 192 is operated and the valve 1
By opening 90, the pressure in tank 170 is reduced to a predetermined pressure. Next, by opening the valve 178, the developer 17 is supplied from the developer supply source 180 to the tank 17.
Within 0, a predetermined amount of the developer is replenished to the upper limit level H.
After the replenishment is completed, the valves 178 and 190 are closed, and the valve 184 is opened again, so that the tank 170 is pressurized to a predetermined pressure atmosphere and enters a standby state. The valves 178, 184, 190
Is controlled to open and close by a controller 138.

Therefore, as shown in FIG.
When neither of the tanks 0 and 174 is open, the pressure in the tank 170 is reduced to a predetermined pressure atmosphere, the developing solution is supplied, and by the time the valves 160 and 174 are opened, the inside of the tank 170 is maintained at a predetermined pressure. It is pressurized to a pressure atmosphere and is in a standby state.

As described above, the developing devices 128 and 12 using the developing solution supply mechanism according to the present embodiment are described.
In No. 9, since the developer supply mechanism from the transfer pipe 162 to the tank 170 is shared, it is possible to suppress an increase in the size of the system and to reduce the manufacturing cost of the system. Further, maintenance of the developing solution supply mechanism is facilitated, and utilization efficiency can be greatly improved.

Next, a developer supply mechanism according to another embodiment will be described. As shown in FIG. 5, the developer supply mechanism includes branch pipes 200 and 202 in a transfer pipe 162.
And a tank 206 is connected to the branch pipe 200 via a valve 204, and to the other branch pipe 202,
The tank 210 is connected via a valve 208. Further, a controller 212 is connected to the valves 204 and 208, and the opening and closing of the valves 204 and 208 are controlled by a control signal of the controller 212.

When the developing solution in the tank 206 reaches the lower limit level L, for example, as shown in FIG. 6, after the valve 160 and the valve 174 are opened and closed, the valve 160 is opened and closed again. Until the opening and closing of the valve 174, the valve 204 is closed and the valve 208 is opened by a control signal from the controller 212. As a result, it is possible to switch to the tank 210 in which the developer is stored up to the predetermined upper limit level H without affecting the developing process. In addition, tank 2
The upper limit level H and the lower limit level L of 06 and 210 are set similarly to the tank 170 shown in FIG.

For example, immediately after switching from the tank 206 to the tank 210, the developer supplied from the tank 206 remains in the developer supply mechanism from the transfer pipe 162 to the developing devices 128 and 129. doing. Therefore, after the switching and when the processing is not performed, the configuration may be such that the above-described residual portion is simulated and discharged. In this case, in the developing device 128 shown in FIG. 2, for example, the developer simulated from the developer discharge nozzle N1 is discharged to the discharge unit 150 and then drained through the drain pipe 154. It is stored in the tank 142. In this way, by simulating the discharge of the residual portion, it is possible to prevent an unexpected situation due to the deterioration of the developing solution when a developing solution that is particularly easily deteriorated is used.

Although the preferred embodiments of the present invention have been described with reference to the accompanying drawings, the present invention is not limited to such configurations. Within the scope of the technical idea described in the claims, those skilled in the art will be able to conceive various changes and modifications, and those changes and modifications are also within the technical scope of the present invention. It is understood that it belongs to.

For example, in the above-described embodiment, the two developing processing devices 128 and 1
Although the configuration provided with 29 has been described as an example, the present invention is not limited to such a configuration, and the present invention can be implemented with a configuration further provided with a plurality of developing devices.

Further, in the above embodiment, by applying the present invention to the development processing devices 128 and 129,
Although a specific example has been described, the present invention is not limited to such a configuration, and can be applied to various types of coating apparatuses. The present invention is also applicable to a glass substrate for use.

[0041]

As described above, according to the present invention,
The valve devices interposed in each branch path should be set so that the time for discharging the processing liquid in each processing device does not overlap.
Since the opening and closing are controlled, even if there are a plurality of processing apparatuses, one processing liquid supply mechanism can be shared and used. Therefore, it is possible to suppress the increase in the size of the system and the manufacturing cost of the system, to facilitate the maintenance, and to improve the utilization efficiency. Further, even when a plurality of tanks for storing the processing liquid are provided and another tank is switched when the processing liquid reaches the lower limit level, the switching operation is performed while the switching device is discharging the processing liquid in each processing apparatus. Since the processing is controlled not to be performed, stable processing can be performed without interrupting the processing steps, and as a result, the throughput is improved.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view of a coating and developing system incorporating a developing apparatus to which the present invention can be applied.

FIG. 2 is a schematic sectional view of a developing apparatus in the coating and developing system shown in FIG.

FIG. 3 is a schematic explanatory view of a developer supply mechanism for supplying a developer to a developing device in the coating and developing system shown in FIG. 1;

FIG. 4 is a schematic explanatory diagram showing operation timings of valves and the like of the developer supply mechanism shown in FIG. 3;

FIG. 5 is a schematic explanatory view of another developing solution supply mechanism for supplying a developing solution to a developing device in the coating and developing system shown in FIG. 1;

FIG. 6 is a schematic explanatory diagram showing operation timings of valves and the like of another developing solution supply mechanism shown in FIG. 5;

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 coating / development processing system 128, 129 development processing device 132 processing container 134 spin chuck 136 drive mechanism 138 controller 158, 172 branch pipe 160, 174 valve 162 transfer pipe 164 heat exchanger 166 filter 168 flow controller 170 tank 180 developer Supply source 186 Gas supply source 192 Vacuum evacuation mechanism N1 Developer discharge nozzle W Wafer

Claims (3)

[Claims] A mechanism for supplying a processing liquid to a plurality of processing apparatuses for supplying a processing liquid to a substrate to be processed and performing a predetermined processing, comprising: a tank for storing the processing liquid; A transfer path for transferring the liquid to the processing apparatus side, a branch path branched from the transfer path to each of the processing liquid discharge units of the processing apparatus, and a branch path interposed in each of the branch paths to open and close the branch path. And a valve device for controlling the opening and closing of the valve devices so that the time for discharging the processing liquid in each of the processing devices does not overlap. 2. A predetermined upper limit level and a lower limit level of the processing liquid to be stored are set in the tank, and the amount between the upper limit level and the lower limit level is set such that each processing apparatus discharges the processing liquid. The upper limit level and the lower limit level are set so that the processing liquid can be replenished into the tank within a period of time during which the tank is not in operation.
The processing liquid supply mechanism according to claim 1. 3. A mechanism for supplying a processing liquid to a plurality of processing apparatuses for supplying a processing liquid to a substrate to be processed and performing a predetermined processing, wherein the plurality of tanks store the processing liquid; A transfer path for transferring the processing liquid from the tank to the processing apparatus side, a switching apparatus for switching a tank which is a supply source among the tanks, and a processing liquid discharge unit of the processing apparatus branched from the transfer path A branch path leading to
A valve device that is interposed in each of the branch paths to open and close the branch path, wherein the valve devices are controlled to open and close so that the time for discharging the processing liquid in each of the processing apparatuses does not overlap. The switching device is controlled so that the switching operation is not performed while the processing liquid is being discharged in each of the processing devices.