JPH11102850A - Substrate-processing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a substrate-processing device, which can accurately regulate the condition of a processing liquid and attain the target condition quickly, even when the condition thereof changes abruptly. SOLUTION: A pressurized nitrogen gas is supplied from a nitrogen gas feeding part 22 to a chemical liquid tank 20, having a sealing structure and the chemical liquid is sent through a chemical distribution route 11. The pressure of nitrogen gas is changed by controlling an anticorrosive regulator 32 operated by a compressed air from an electropneumatic regulator 32. Thus, as a result the pressure in the route 11 is controlled. A controller 35 controls the electropneumatic regulator 32 by PID controlling, when a pressure sensor 25 indicates that the pressure of chemical liquid in the route 11 is near a target value and by outputting of a constant value, when the sensor 25 indicates that the pressure thereof is significantly different from the target value, respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate processing apparatus for performing processing on various substrates to be processed such as a semiconductor wafer, a glass substrate for a liquid crystal display device, and a PDP (plasma display panel).

[0002]

2. Description of the Related Art In a substrate processing apparatus for cleaning a substrate, a processing liquid is supplied to the substrate, and the processing of the surface of the substrate is performed by the processing liquid. As the treatment liquid, pure water or a treatment liquid obtained by diluting a chemical such as hydrofluoric acid, sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid, acetic acid, ammonia, or hydrogen peroxide to a predetermined concentration with pure water is used.

In order to prepare a processing chemical having a controlled concentration, this type of substrate processing apparatus supplies, for example, a chemical tank having a pressure-tight structure and a nitrogen gas having a controlled pressure into the chemical tank. Nitrogen gas supply means and the chemical solution from the chemical solution tank and pure water from the pure water supply source are led,
And a mixing valve for mixing them. The nitrogen gas supply means includes, for example, a regulator for adjusting the supply pressure of the nitrogen gas, a pressure sensor for detecting the pressure of the chemical supplied from the chemical tank to the mixing valve, a detection value of the pressure sensor and a target pressure value. And a programmable controller that performs feedback control of the operation of the regulator based on the deviation from the above. With this configuration, the chemical flow rate to the mixing valve is strictly controlled,
The concentration of the treatment solution prepared by mixing with pure water is stabilized.

[0004] Of course, the flow rate of pure water supplied to the mixing valve is also fixed, but the mixing ratio between the stock solution of chemical solution and pure water is, for example, 1:20 to 1: 200. Control of the flow rate of pure water does not need to be as strict as control of the flow rate of the undiluted chemical solution.

[0005]

However, in the above configuration in which the pressure of the nitrogen gas is simply controlled based on the difference between the detected pressure value and the target pressure value, the control accuracy is not sufficient, and the mixing is performed by the mixing valve. In some cases, a large variation occurs in the concentration of the processing solution supplied to the substrate. For this reason, processing on a plurality of substrates cannot be performed uniformly, and there is a possibility that the quality of the substrates may be degraded.

The detection of the pressure value by the programmable controller is performed by sampling the output value of the pressure sensor a plurality of times and taking an average value thereof (for example, eight times in 0.2 seconds). Therefore, a time delay with respect to the pressure control was inevitable. In particular, when opening and closing an exhaust valve for exhausting a chemical solution tank, the pressure of the chemical solution fluctuates rapidly, but there is a problem that the response to such a rapid pressure fluctuation is poor. Was.

A so-called PID for improving control accuracy
It is conceivable to use control, but even in PID control, it is not possible to have sufficient responsiveness to the above-mentioned sudden change in the chemical pressure. That is, no matter how the PID constant is set, the operation amount fluctuates greatly after the chemical liquid pressure changes suddenly, and so-called hunting cannot be avoided. Therefore, the pressure of the chemical cannot be brought to the target pressure, and a large amount of the processing chemical having an inappropriate concentration may be generated.

An object of the present invention is to solve the above-mentioned technical problems and to provide a substrate processing apparatus capable of processing a substrate with a processing liquid in a well-controlled state. A more specific object of the present invention is to provide a substrate processing apparatus that can accurately control the state of a processing liquid and can quickly lead to a target state even when the state of the processing liquid changes suddenly. It is to be.

[0009]

Means for Solving the Problems and Effects of the Invention According to the first aspect of the present invention, there is provided a processing liquid flow path through which a processing liquid for performing processing on a substrate flows. A state detection unit that detects the state of the processing liquid flowing through the processing liquid flow path and outputs the detected state as a state detection value; a state target value storage unit that stores a state target value that is a target in the state detection unit; A state changing unit for changing the state of the processing liquid flowing through the flow passage; and PI control for controlling and operating the state changing unit based on the state detection value by performing a proportional operation and an integral operation as a control law. Department and
A constant value output unit that operates by giving a predetermined constant output value corresponding to the state target value to the state change unit.

According to this configuration, since the PI control section and the constant value output section are provided, the two operation sections are appropriately switched and used so that the state detection value reaches the state target value. Is reduced, and the state of the processing liquid can be stabilized. Thus, the substrate can be processed with the processing liquid in a stable state, so that good substrate processing can be performed. For example, if the PI control unit is normally used and a constant value output unit is used temporarily when the state detection value due to disturbance or the like changes suddenly, the state of the processing liquid can be controlled accurately, and the disturbance can be controlled. You can also recover faster from

The state of the processing liquid includes, for example, the pressure of the processing liquid, the flow rate of the processing liquid, and the concentration of the processing liquid. Further, the treatment liquid whose state is changed may be a drug solution stock solution not mixed with pure water, or a mixed solution generated by mixing a drug solution and pure water at a predetermined mixing ratio. Good.

According to a second aspect of the present invention, when the state detection value is a value within a predetermined range including the state target value, the PI control section operates the state change section,
2. The substrate processing apparatus according to claim 1, further comprising an operation switching unit that operates the state change unit by the constant value output unit when the state detection value is outside the predetermined range. It is.

According to this configuration, when the state detection value changes suddenly due to disturbance or the like and greatly deviates from the state target value, the state change section is controlled by the constant value output section.
Hunting, which is a concern when the control by the PI control unit is continued, can be quickly eliminated. This allows
Since the state of the processing liquid can be further stabilized, the processing on the substrate can be performed satisfactorily.

According to a third aspect of the present invention, when the state detection value is a value within a predetermined range including the state target value continuously for a predetermined time or more, the PI control unit controls the state change unit. Operating, further comprising an operation switching unit for operating the state changing unit by the constant value output unit when the state detection value is a value outside the predetermined range for a predetermined time or more. 2. The substrate processing apparatus according to claim 1, wherein:

According to this configuration, since it is possible to make a decision based on the detected state value after confirming that a certain state has continued for a predetermined time or more, the detected state value is transmitted to the operation switching unit. In such a case, the state detection value is not instantaneously converted to a value different from the actual value due to an unnecessary signal such as noise, and the operation switching unit does not erroneously recognize.

According to a fourth aspect of the present invention, there is provided a closed storage container connected to one end of the processing liquid flow passage for storing the processing liquid, and connected to the storage container to supply gas to the storage container. The substrate processing apparatus according to any one of claims 1 to 3, further comprising a pressurized gas supply path for pressurizing. According to this configuration, the processing liquid can be sent out to the processing liquid flow passage by supplying gas to the storage container and pressurizing the gas, so that it is not necessary to use an expensive pump or the like. In addition, if a state detecting unit or a state changing unit is provided in association with the pressurized gas supply path and configured to detect or change the state of the pressurized gas in the pressurized gas supply path, these may be liquid-resistant. (When the treatment liquid is a chemical, it is not necessary to have chemical resistance). This allows
Further cost reduction is achieved.

According to a fifth aspect of the present invention, there is provided a pure water flow passage through which pure water flows, a mixing valve connected to the processing liquid flow passage and the pure water flow passage for mixing the processing liquid and pure water,
5. The substrate processing apparatus according to claim 1, further comprising a mixed liquid supply path for supplying the mixed liquid mixed by the mixing valve to the substrate.

According to this configuration, when the mixing ratio of the processing liquid (for example, undiluted chemical solution) and pure water is high (for example, 1:
20), the concentration of the mixed liquid can be made constant by accurately controlling the state (pressure and flow rate) of the processing liquid. Therefore, by using a combination of PI control and constant value control to change the state of the processing liquid, the concentration of the mixed liquid can be adjusted with high accuracy.

The state value of the processing solution may be a pressure value of the processing solution. The state detection value of the processing liquid may be a flow rate value of the processing liquid. The state detection value of the processing liquid may be a concentration value of the processing liquid. Particularly when two types of liquids are mixed (for example, in the case of the invention of claim 5), the concentration of the mixed liquid can be accurately controlled by setting the state detection value of the processing liquid as the concentration value of the processing liquid.

[0020]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a flowchart mainly showing a configuration related to generation of a processing liquid in the substrate processing apparatus according to the first embodiment of the present invention. This substrate processing apparatus mixes a processing chemical (mixed liquid) generated by mixing pure water and a chemical at a predetermined mixing ratio with a substrate W such as a semiconductor wafer held and rotated by a spin chuck 1. This is an apparatus for supplying and treating the surface of the substrate W with the treatment liquid.

A spray nozzle 2 is arranged so as to face the upper surface of the substrate W. The spray nozzle 2 is supplied with a processing chemical solution stored in a processing chemical solution storage tank 3 by a discharge pump 4. The power is supplied via a road 5. An electromagnetic valve 6 and a concentration monitor 7 are disposed in the processing liquid supply path 5, and by opening and closing the electromagnetic valve 6, the supply / stop of the processing chemical liquid to the substrate W can be controlled.
The concentration monitor 7 can detect the concentration of the processing chemical supplied to the substrate W.

A processing chemical solution of a predetermined concentration is supplied to the processing chemical solution storage tank 3 from a mixing valve 8. The pure water from the pure water supply source 9 is supplied to the mixing valve 8 in a state where the pressure is controlled by a regulator 19, and the chemical liquid undiluted solution in which the pressure from the chemical liquid supply device 10 is controlled (in this embodiment, (Corresponding to the “processing liquid” to be changed). The path of the treatment liquid from the mixing valve 8 to the spray nozzle 2 corresponds to a mixed liquid supply path.

From the chemical supply device 10, a chemical flow passage 11 is provided.
The chemical liquid from the (processing liquid flow passage) is supplied to the pair of branch pipes 12 and 13.
Is supplied to the mixing valve 8 via the When the chemical solution is supplied from one branch pipe 12 to the mixing valve 8, the mixing ratio between the chemical solution and pure water becomes 1: 200, and the chemical solution flows from the other branch pipe 13 to the mixing valve 8. When the chemical is supplied, the mixing ratio of the chemical to the pure water is set to 1:20.

Each of the branch pipes 12 and 13 has a solenoid valve 1
4 and 15 are interposed, and any of the branch pipes 12 and 13
Thus, a chemical solution can be introduced into the mixing valve 8. Similarly, the introduction of pure water from the pure water supply source 9 can be controlled by turning on / off a solenoid valve 17 interposed in the pure water supply passage 16 (pure water flow passage). . The water pressure in the pure water supply path 16 is detected by a pressure sensor 18.

The chemical solution supply device 10 includes a chemical solution tank 20 (reservoir) having a closed structure having corrosion resistance, and a chemical solution stock solution (for example, hydrofluoric acid, sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid, acetic acid, ammonia, Hydrogen oxide water etc.)
And a nitrogen gas supply unit 22 (pressurized gas supply unit) that supplies nitrogen gas as an inert gas whose pressure is controlled to the chemical solution tank 20.

The chemical solution supply passage 20 is connected to the chemical solution flow passage 11 described above, and in relation to the chemical solution flow passage 11, a pressure sensor 25 (state) for detecting the pressure of the chemical solution flowing through the inside thereof. Detector). Also,
The chemical from the chemical supply source 21 is supplied to the chemical tank 20 as needed via a chemical supply path 27 in which a pump 23 and an electromagnetic valve 24 are interposed. Further, an exhaust path 28 is connected to the chemical tank 20, and by opening an exhaust electromagnetic valve 29 interposed in the exhaust path 28, the inside of the chemical tank 20 can be exhausted. .

The nitrogen gas supply section 22 supplies the pressurized nitrogen gas to the chemical liquid tank 20 via the gas supply path 30, and thereby operates to feed the chemical liquid whose pressure is controlled into the chemical liquid flow path 11. That is, the nitrogen gas supply unit 22
A nitrogen gas supply source 31 for supplying a constant pressure of nitrogen gas,
An electropneumatic regulator 32 provided between the nitrogen gas supply source 31 and the gas supply path 30;
And a solenoid valve 36 interposed between the nitrogen gas supply source 31. Pressurized air from a compressed air supply source 34 is supplied to a pilot port of the electropneumatic regulator 32. And electropneumatic regulator 3
2 is controlled by an electric control signal from the controller 35. Controller 35
Is controlled based on the pressures detected by the pressure sensor 18 and the pressure sensor 25 as described later.
Control. In the present embodiment, the applied voltage is used as the electric control signal, but may be an applied current instead of the applied voltage.

The electropneumatic regulator 32 controls the pressure of the nitrogen gas passing through the electropneumatic regulator 32 in accordance with the voltage applied from the controller 35. Therefore, by controlling the voltage applied to the electropneumatic regulator 32 by the controller 35, the pressure of the nitrogen gas supplied to the chemical liquid tank 20 can be controlled, and as a result, the pressure of the chemical liquid sent to the chemical liquid flow passage 11 is controlled. be able to. Thus, in this embodiment, the state change unit is configured by the electropneumatic regulator 32.

The controller 35 includes a CPU 35a, an RO
It has an M35b and a RAM 35c, and has a basic form as a programmable controller. The controller 35 determines a target pressure value of the chemical flowing through the chemical flow passage 11 based on the water pressure detected by the pressure sensor 18, and the detected pressure value of the pressure sensor 25 becomes equal to the target pressure value determined above. The electropneumatic regulator 32 is controlled as described above. In this embodiment, the target pressure value is calculated by the CPU 35a as a value obtained by adding 0.2 kgf / cm ² to the water pressure detected by the pressure sensor 18, and stored in the RAM 35c as a state target value storage unit.

In controlling the electropneumatic regulator 32,
A so-called PID control based on the pressure detection value of the pressure sensor 25 and a constant value output for keeping the operation amount constant regardless of the pressure detected by the pressure sensor 25 are applied by switching. That is, the controller 35 has functions as a PI control unit, a constant value output unit, and a control switching unit. In addition,
A display unit 37 is connected to the controller 35,
For example, when an abnormality occurs in the pressure of the nitrogen gas supply source 31, the abnormality can be notified.

Hereinafter, referring to the flowchart of FIG.
The details of the control operation by the controller 35 will be described. Ko
First, the controller 35 detects the pure state detected by the pressure sensor 18.
The water supply pressure detection value PW is taken in (step S1),
This pure water supply pressure detection value PW is 0.2 kgf / cm ^TwoAdd
By calculating the target pressure value PO, the RAM 35
c (step S2). And the pressure sensor 2
5 captures the chemical supply pressure detection value PC detected by the
Step S3), the detected value of the chemical supply pressure PC and the target pressure value
The absolute value of the difference from PO is calculated as the deviation δP (step
S4). In this embodiment, the controller 35
Are the sampling results of the output values of the pressure sensors 18 and 25
Is the pure water supply pressure detection value PW and the chemical supply pressure
It is used as each of the detection values PC.
The response speed has been improved by eliminating the average calculation such as
I have.

The controller 35 further determines whether or not the deviation δP exceeds a predetermined threshold TH (for example, 0.1 kgf / cm ² ) (step S5). If the deviation δP does not exceed the threshold value TH, that is, if the chemical solution supply pressure detection value PC is, for example, ± 0.10 of the target pressure PO,
If the value is within the range of 0 kgf / cm ² , control of the electropneumatic regulator 32 is performed by PID control (Step S).
6).

If the deviation δP exceeds the threshold value TH (YES in step S5), the electropneumatic regulator 32 is controlled by a constant output value regardless of the chemical solution supply pressure value PC detected by the pressure sensor 25. Is controlled (step S
7). The constant value in this case is determined by the target pressure value P stored in the RAM 35c in accordance with a predetermined pressure linear equation.
It is determined based on O.

The linear equation of the pressure is, for example, the voltage applied to the electropneumatic regulator 32 when the chemical supply pressure detected by the pressure sensor 25 becomes 0.6 kgf / cm ² and the chemical supply supplied by the pressure sensor 25 similarly. Pressure is 1.0kgf / cm ²
The voltage applied to the electropneumatic regulator 32 at the time of is measured in advance, and based on this, a linear equation representing the relationship between the chemical solution supply pressure and the voltage applied to the electropneumatic regulator 32 is determined. For this linear equation,
A value obtained by substituting the target pressure value PO is a constant output value to be applied to the electropneumatic regulator 32.

When the deviation δP exceeds the threshold value TH, the constant value output as described above is performed, and the duration T in which the deviation δP exceeds the threshold value TH is measured. This duration T is a fixed time (for example, 40 seconds)
(Step S8), a message indicating that an abnormality has occurred in the pressure of the nitrogen gas supply source 31 is displayed on the display unit 37 connected to the controller 35 (step S9).

The processing from step S1 is repeated before the duration T in which the deviation δP exceeds the threshold value TH reaches the predetermined time. The same applies when PID control is performed (step S6). FIG.
Is a diagram for explaining an operation in a case where the chemical supply pressure changes suddenly due to a disturbance such as the opening and closing of the exhaust solenoid valve 29, and shows a temporal change of the chemical supply pressure detection value PC. I have.

During the period before the above-mentioned disturbance occurs at time t1, as a result of the control of the electropneumatic regulator 32 by the PID control, the chemical solution supply pressure detection value PC becomes the target pressure value P
It is stable at a value near O. If a disturbance occurs at time t1, the chemical solution supply pressure detection value PC changes greatly,
If the PID control is continued as it is, the chemical solution supply pressure cannot be stabilized in the subsequent period, and hunting occurs semipermanently.

The fact that the detected value PC of the chemical supply pressure has changed abruptly is determined by the processing of step S5 in FIG.
5, the constant value output (step S7 in FIG. 2) is performed during the period from time t2 thereafter.
As a result, the chemical solution supply pressure detection value PC quickly approaches the target pressure value PO without hunting. Then, at time t3 when the chemical supply pressure detection value PC becomes a value in the range (range of PO ± TH) near the target pressure value PO, the control is switched to the PID control, and thereafter, the chemical supply pressure is changed to the target pressure value. It will be precisely controlled by PO.

As described above, according to this embodiment, the PI
By adopting the D control, the chemical solution supply pressure can be controlled with high precision, so that the mixing ratio of the chemical solution and pure water in the mixing valve 8 can be accurately adjusted to a desired mixing ratio. Therefore, it is possible to prevent the concentration of the processing solution supplied to the substrate W from being varied, so that a uniform processing can be performed on a plurality of substrates W.

In addition, when the chemical supply pressure suddenly changes due to disturbance or the like, hunting is prevented by controlling the electropneumatic regulator 32 with a constant output value regardless of the chemical supply pressure detection value PC. The period of occurrence is shortened so that the chemical solution can be promptly supplied at an appropriate pressure. With this, even if disturbance occurs,
The supply of the chemical solution can be stabilized promptly.

FIG. 4 is a flowchart for explaining a control operation in the substrate processing apparatus according to the second embodiment of the present invention. The configuration of the substrate processing apparatus of the second embodiment is as follows.
This is the same as the configuration of the device of the first embodiment described above, and only the operation of the controller 35 is different. Therefore, this embodiment will be described below with reference to FIG. In FIG. 4, steps in which substantially the same processes as those in FIG. 2 described above are performed are denoted by the same reference numerals as in FIG. 2.

In the second embodiment, the controller 35 sets the condition that the state where the deviation δP exceeds the threshold value TH has continued for a predetermined first time T1 (for example, 3 seconds) (step S21). ), The control operation is switched from PID control (step S6) to constant value output (step S7). That is, if the state in which the chemical supply pressure detection value PC takes a value outside the range of PO ± TH around the target pressure value PO continues for the first time T1 or more, the output is switched to a constant value output.

When the output of the constant value is started, the controller 35 fetches the chemical solution supply pressure detection value PC, the pure water supply pressure detection value PW, and the like, and monitors the fluctuation of the deviation δP. The state in which the deviation δP is smaller than the threshold value TH is preferably a second time T2 (T2> T1),
For example, T2 = 15 seconds. ) (Step S22), the control operation is switched from the constant value output to the PID control (step S6). That is, the detected value of the chemical solution supply pressure PC becomes P around the target pressure value PO.
The PID control is returned on condition that the state of taking a value within the range of O ± TH has continued for the second time T2.

If the state in which the chemical solution supply pressure detection value PC takes a value outside the range of PO ± TH for more than the third time T3 (for example, 40 seconds) even though the constant value control is performed, (Step S8), it is determined that an abnormality has occurred in the nitrogen gas pressure. FIG. 5 is a diagram for explaining an operation when the chemical supply pressure is suddenly changed due to a disturbance such as the opening and closing of the exhaust solenoid valve 29, and a time change of the chemical supply pressure detection value PC is shown. Have been.

During a period before the above-mentioned disturbance occurs at time t11, the electropneumatic regulator 32 by PID control is used.
As a result of this control, the chemical solution supply pressure detection value PC is stable at a value near the target pressure value PO. However, the pressure sensor 2
In some cases, as indicated by reference numerals A1, A2, and A3, the chemical solution supply pressure detection value PC temporarily takes a value outside the range of PO ± TH due to noise mixed into the output signal of No. 5 and the like. In these cases, since the chemical supply pressure does not fluctuate significantly, the chemical supply pressure detection value PC does not take a value outside the range of PO ± TH for a long time.

On the other hand, if a disturbance occurs at time t11, the detected value of the chemical supply pressure PC sharply changes, and takes a value outside the range of PO ± TH continuously over the first time T1.
Therefore, the output is switched to the constant value output (step S7 in FIG. 4) at time t12. As a result, the chemical supply pressure detection value PC quickly approaches the target pressure value PO. Then, the chemical solution supply pressure detection value PC becomes the target pressure value P
At time t14 when the second time T2 has elapsed from time t13 at which the value falls within the range near O (the range of PO ± TH), the control is switched to the PID control, and thereafter, the chemical solution supply pressure accurately matches the target pressure value PO. Will be controlled.

As described above, according to this embodiment, in addition to the same effects as those of the above-described first embodiment, the effects of unnecessary signals such as noise are eliminated, and PID control and constant value output are performed. Can be appropriately switched.
Thereby, the control of the chemical solution supply pressure can be performed more precisely, so that the processing on the substrate W can be performed more favorably.

The PID control will be outlined below. P
The ID control is control in accordance with a control law including a proportional operation (P operation), an integral operation (I operation), and a differential operation (D operation). The PID control is a control amount of a control target (that is, a control amount after control). (Observed amount) can be quickly brought close to the target value.

That is, if the deviation is small, the operation amount is small, and if the deviation is large, it is appropriate to increase the operation amount accordingly. Therefore, the control law includes a term proportional to the deviation. This is called a proportional operation (P operation). Further, if only proportional control is performed on a control target having self-balancing properties, a constant deviation called a steady-state deviation (offset) will ultimately remain with respect to a step-like change due to a target value or a disturbance. This steady-state deviation can be eliminated by including a term proportional to the integral of the deviation in the control law. This is called an integration operation (I operation). Furthermore, a term proportional to the derivative of the deviation may be included in the control law in order to quickly bring the controlled object closer to the target value with respect to the sudden increase in the deviation.
This is called a differential operation (D operation). However, for the purpose of controlling the chemical solution supply pressure in this embodiment, the differential operation may or may not be used (that is, PI control may be used).

Although the embodiments of the present invention have been described above, the present invention can be implemented in other embodiments. For example, in the above embodiment, by controlling the electropneumatic regulator 32, the nitrogen gas pressure is controlled,
The chemical supply pressure is controlled through this, but instead, a chemical-resistant regulator may be arranged in the chemical flow passage 11 to directly control the chemical supply pressure. Further, in the above embodiment, the chemical solution supply pressure is detected.
And the inside of the chemical solution tank 20, etc.
May be provided, and the electropneumatic regulator 32 may be controlled such that the detected value of the pressure sensor becomes a predetermined target value.

Further, in the above embodiment, the chemical solution supply pressure is controlled. However, a flow rate sensor is provided in the chemical solution flow passage 11 to detect the flow rate of the chemical solution, and the power is supplied so that the flow rate becomes the target value. The empty regulator 32 may be controlled.
Of course, a regulator may be arranged in the chemical liquid flow passage 11, and the regulator may be controlled based on the detection value of the flow sensor. That is, the flow rate may be controlled.

Further, a concentration sensor is arranged in a path of the mixed liquid from the mixing valve 8 to the processing chemical solution storage tank 3, and an electropneumatic regulator 32 is provided based on an output of the concentration sensor.
Alternatively, a regulator disposed in the chemical liquid passage 11 may be controlled. In addition, various design changes are made within a range of technical matters described in the claims, such as performing control by combining two or more of the pressure of the chemical solution, the flow rate of the chemical solution, and the concentration of the processing chemical solution. Is possible.

[Brief description of the drawings]

FIG. 1 is a flowchart showing a configuration related to supply of a processing liquid in a substrate processing apparatus according to a first embodiment of the present invention.

FIG. 2 is a flowchart for explaining a control process of a chemical solution supply pressure.

FIG. 3 is a graph showing a temporal change of a chemical solution supply pressure detection value when a disturbance occurs.

FIG. 4 is a flowchart illustrating a control process of a chemical solution supply pressure in a substrate processing apparatus according to a second embodiment of the present invention.

FIG. 5 is a graph showing a temporal change of a chemical solution supply pressure detection value when a disturbance occurs in the substrate processing apparatus of the second embodiment.

[Explanation of symbols]

Reference Signs List 8 mixing valve 9 pure water supply source 10 chemical liquid supply device 11 chemical liquid flow path 16 pure water supply path 18 pressure sensor 20 chemical liquid tank (storage container) 22 nitrogen gas supply unit 25 pressure sensor (state detection unit) 30 gas supply path Pressure gas supply unit) 31 nitrogen gas supply source 32 electropneumatic regulator (state change unit) 34 compressed air supply source 35 controller (PI control unit, constant value output unit and operation switching unit) 35c RAM (state target value storage unit)

Claims (8)

[Claims] 1. A processing liquid flow path through which a processing liquid for performing processing on a substrate flows, and a state detection unit that detects a state of the processing liquid flowing through the processing liquid flow path and outputs the detected state as a state detection value. A state target value storage unit that stores a target state target value in the state detection unit; a state change unit that changes the state of the processing liquid flowing through the processing liquid flow path; and a proportional operation and a control law. A PI control unit that controls and operates the state change unit based on the state detection value by performing an integration operation; and a constant output value that is predetermined in correspondence with the state target value and the state change unit And a constant value output unit for operating the substrate processing apparatus. 2. When the state detection value is a value within a predetermined range including the state target value, the PI control unit operates the state change unit to change the state detection value to the predetermined range. 2. The substrate processing apparatus according to claim 1, further comprising an operation switching unit that operates the state changing unit by the constant value output unit when the value is outside the range. 3. When the state detection value is a value within a predetermined range including the state target value continuously for a predetermined time or more,
The state control unit is operated by the PI control unit, and when the state detection value is a value outside the predetermined range for a predetermined time or more, the state change unit is operated by the constant value output unit. 2. The substrate processing apparatus according to claim 1, further comprising an operation switching unit. 4. A closed storage container connected to one end of the processing liquid flow passage for storing the processing liquid, and a pressurizing device connected to the storage container for supplying gas to the storage container to pressurize the storage container. 4. The substrate processing apparatus according to claim 1, further comprising a gas supply path. 5. A pure water flow path through which pure water flows, a mixing valve connected to the processing liquid flow path and the pure water flow path, and mixing the processing liquid and pure water, and a mixing valve. 5. The substrate processing apparatus according to claim 1, further comprising a mixed liquid supply passage for supplying the mixed liquid to the substrate. 6. The substrate processing apparatus according to claim 1, wherein the state detection value of the processing liquid is a pressure value of the processing liquid. 7. The substrate processing apparatus according to claim 1, wherein the state detection value of the processing liquid is a flow rate value of the processing liquid. 8. The substrate processing apparatus according to claim 1, wherein the state detection value of the processing liquid is a concentration value of the processing liquid.