JPH1167707A - Substrate processing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance efficiency when the processing liquid in a substrate processing part is replaced with new processing liquid and to save the processing liquid required for the replacement by setting two targets among a chemical- flow-rate target, a pure-water flow-rate target and the concentration target of the processing liquid, and to change one target with the elapsed time. SOLUTION: In a target setting part 30A, the targets, which are changed with the elapse of time, e.g. a chemical-flow-rate target a1 and a pure-water- flow-rate target a2 are outputted based on the specified variables from a target output part through a variable specifying part. Then, a chemical-concentration- returning control part 40A obtains a processing-liquid-concentration target a3, which is determined unequivocally, from the targets a1 and a2. The concentration C3 between the target a3 and the present concentration b3 of the processing liquid is obtained. A chemical-flow-rate operating amount d1 is adjusted so as to erase the deviation C3. The operating amount d1 is changed to a chemical- flow-rate operating voltage Vd1 and imparted to a pure-water-change returning part 60A. The chemical-flow-rate operating voltage Vd1', which is corrected from the voltage Vd1, is inputted into an electric-neumatic converter 20.

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 a surface treatment on a substrate such as a semiconductor wafer or a glass substrate for a liquid crystal display with a processing liquid, and more particularly to a substrate processing apparatus obtained by mixing a chemical solution and pure water. The present invention relates to a technique for controlling the concentration of a processing solution.

[0002]

2. Description of the Related Art Conventionally, as a substrate processing apparatus of this type, for example, an apparatus described in Japanese Patent Application Laid-Open No. 7-22369 is known. This apparatus includes a substrate processing tank for performing a surface treatment on a substrate, and a processing liquid supply unit for supplying a processing liquid to the substrate processing tank. The processing liquid supply section is provided with a pure water supply path and a chemical liquid supply path. The pure water supply path is connected between the substrate processing tank and a pure water supply source. One end of the chemical supply path is introduced into the chemical in the chemical tank, and the other end is connected to the pure water supply path via a chemical introduction valve. Pressurized nitrogen gas is introduced into the chemical liquid tank, and the chemical liquid in the chemical liquid tank is pressurized by the gas pressure, whereby the chemical liquid is pressure-fed to the chemical liquid supply path.

The chemical liquid introduction valve has a chemical liquid supply path connected to the inlet side and a pure water supply path connected to the outlet side, and a differential pressure between the chemical liquid pressure on the inlet side and the pure water pressure on the outlet side. Is introduced into the pure water supply path on the outlet side.

A pressure sensor for detecting the pressure of the chemical is attached to the chemical supply path. The detection signal of this pressure sensor is given to a gas pressure control unit that controls the pressure of nitrogen gas introduced into the chemical liquid tank. The gas pressure control unit obtains a deviation between the detection signal and a predetermined reference value, and controls the pressure of the nitrogen gas so as to cancel the deviation. As a result, the chemical pressure in the chemical supply path is maintained constant.
On the other hand, a pure water pressure regulator (pressure control valve) is provided in the pure water supply path. The pressure and flow rate of the pure water flowing through the secondary-side pure water supply path are set to constant values by the pure water pressure regulator.

As described above, the chemical liquid pressure at the inlet side of the chemical liquid introduction valve is controlled to be constant, and the pure water pressure at the outlet side of the chemical liquid introduction valve is set to a constant value, whereby the inlet liquid is controlled. The pressure difference between the chemical pressure on the outlet side and the pure water pressure on the outlet side becomes constant, and the chemical liquid at a flow rate according to the differential pressure is introduced into the pure water, so that a processing liquid having a predetermined concentration can be obtained. I have.

[0006]

Since the above-described substrate processing apparatus processes a substrate with a processing solution having a constant concentration, a control amount such as a chemical solution flow rate, a pure water flow rate, or a processing solution concentration is used. Is set to a constant value over time. However, if the target value of the control amount is set to be constant over time, it is not possible to cope with the inconvenience as described below, and there is a problem that the degree of freedom of control of this type of substrate processing apparatus is reduced. .

That is, if the target value of the control amount is made constant over time, (a) when the processing liquid in the substrate processing tank is replaced with a new processing liquid, the substrate processing tank is filled with the new processing liquid. However, problems such as an increase in the time required for the replacement, (b) an increase in the amount of the processing solution required for replacement, and (c) unevenness in the density of the processing solution in the substrate processing bath occur.

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and efficiently replaces a processing solution in a substrate processing unit, saves a processing solution required for replacement, or processes a processing solution in a substrate processing unit. An object of the present invention is to provide a substrate processing apparatus having a high degree of freedom in control, such as suppressing unevenness in concentration of a liquid.

[0009]

The present invention has the following configuration in order to achieve the above object. That is, the invention according to claim 1 is a substrate processing apparatus for performing a surface treatment of a substrate with a processing liquid obtained by mixing pure water and a chemical solution, and a substrate processing for performing a surface treatment of the substrate with the processing liquid. Department and
A pure water supply path connected between the substrate processing unit and the pure water supply source, a chemical liquid tank having a sealed structure for storing a chemical liquid, and a chemical liquid supply path having one end introduced into the chemical liquid in the chemical liquid tank. A chemical liquid pressure feeding means for feeding a chemical liquid in the chemical liquid tank to the chemical liquid supply path, and an inlet side at the other end of the chemical liquid supply path,
An outlet side connected to the pure water supply path, a chemical liquid introduction valve for introducing a chemical liquid into the pure water supply path at a flow rate corresponding to a pressure difference between the inlet side chemical liquid pressure and the outlet side pure water pressure; A chemical solution pressure regulator that adjusts a chemical solution pressure in the chemical solution supply channel based on the flow rate operation amount, and a chemical solution regulator is disposed in the pure water supply channel upstream of a position where a chemical solution is introduced into the pure water supply channel. A pure water pressure regulator that adjusts the pure water pressure in the pure water supply path based on the pure water flow manipulated variable, and a chemical solution flow target value, a pure water flow target value, and a treatment liquid concentration target value. Target value setting means for setting at least one of the two target values and changing at least one of the two target values over time, and a target value set by the target value setting means. The medicine given to the medicine pressure regulator by adjusting the operation amount of the medicine flow based on the medicine A flow control amount adjusting means, and a pure water flow control amount adjusting means for adjusting the pure water flow control amount based on the target value set by the target value setting means and giving the pure water flow control amount to the pure water pressure regulator. It is characterized by:

According to a second aspect of the present invention, there is provided a substrate processing apparatus for performing a surface treatment of a substrate with a processing solution obtained by mixing pure water and a chemical solution, wherein the substrate is provided with a processing solution. A processing unit, a pure water supply path connected between the substrate processing unit and a pure water supply source, a chemical solution tank having a closed structure for storing a chemical solution, one end is introduced into the chemical solution in the chemical solution tank, The other end is connected in the middle of the pure water supply path, a chemical supply path, a chemical liquid pressure feeding means for sending the chemical in the chemical tank to the chemical supply path, and the opening degree of the valve is operated based on the chemical liquid flow rate operation amount. And a chemical liquid flow rate control valve for adjusting a chemical liquid flow rate in the chemical liquid supply path, and a pure water supply path disposed upstream of a position where the chemical liquid is introduced into the pure water supply path, Pure water pressure for adjusting the pure water pressure in the pure water supply path based on the flow rate operation amount A controller, setting two target values of the chemical solution flow target value, the pure water flow target value, and the treatment liquid concentration target value, and setting at least one target value of the two set target values. Target value setting means for changing with the passage of time, based on a target value set by the target value setting means, a chemical liquid flow operation amount adjustment means for adjusting the chemical liquid flow operation amount and giving the chemical liquid flow control valve to the chemical liquid flow control valve, And a pure water flow control amount adjusting means for adjusting the pure water flow control amount based on the target value set by the target value setting means and giving the pure water flow control amount to the pure water pressure regulator.

According to a third aspect of the present invention, in the device according to the first or second aspect, the target value setting means sets a chemical liquid flow target value and a pure water flow target value.

According to a fourth aspect of the present invention, in the apparatus according to the third aspect, the target value setting means starts supplying a processing liquid into the substrate processing section filled with pure water. Until the inside of the substrate processing section is replaced with the processing liquid, the initial target values of the chemical liquid flow target value and the pure water flow target value are set higher than the subsequent target values.

According to a fifth aspect of the present invention, in the apparatus according to the third aspect, the target value setting means starts supplying a processing liquid into the substrate processing section filled with pure water. Until the inside of the substrate processing unit is replaced with the processing liquid, the initial target value of the chemical liquid flow target value is set higher than the subsequent chemical liquid flow target value, while the pure water flow target value is set constant. It is.

According to a sixth aspect of the present invention, in the apparatus according to the third aspect, the target value setting means starts supplying a processing liquid into the substrate processing unit filled with pure water. Until the inside of the substrate processing unit is replaced with the processing liquid, the target value of the chemical liquid flow rate is set to be constant, while the initial target value of the pure water flow target value is set higher than the subsequent pure water flow target value. Things.

According to a seventh aspect of the present invention, in the apparatus according to the first or second aspect, the target value setting means sets a target concentration of the processing liquid and a target value of the pure water flow rate.

According to an eighth aspect of the present invention, in the apparatus according to the seventh aspect, the target value setting means starts supplying a processing solution into the substrate processing unit filled with pure water. Until the inside of the substrate processing unit is replaced with the processing liquid, the concentration target value of the processing liquid is set to be constant, and as the replacement with the processing liquid progresses, the pure water flow rate target value is changed from its initial target value. Is also to be reduced.

According to a ninth aspect of the present invention, in the apparatus according to the first or second aspect, the target value setting means sets a target concentration of the treatment liquid and a target value of the chemical flow rate.

According to a tenth aspect of the present invention, in the apparatus according to the ninth aspect, the target value setting means starts supplying a processing liquid into the substrate processing unit filled with pure water. Until the inside of the substrate processing unit is replaced with the processing liquid, the initial target value of the processing liquid concentration target value is set to be larger than the subsequent processing liquid concentration target value, while the chemical liquid flow rate target value is kept constant. To set.

According to an eleventh aspect of the present invention, in the apparatus according to the first or second aspect, the target value setting means specifies a type of a target value to be set, and Target value specifying means for specifying a variable for determining the change pattern; and target value output means for generating and outputting a target value that changes over time based on the specified variable. .

[0020]

The operation of the first aspect of the invention is as follows. The chemical solution pumping means supplies the chemical solution in the chemical solution tank to the inlet side of the chemical solution introduction valve via the chemical solution supply passage. On the other hand, pure water is supplied to the outlet side of the chemical liquid introduction valve via a pure water supply path. At this time,
The chemical liquid flow operation amount adjusting means adjusts the chemical liquid flow operation amount based on the target value set by the target value setting means, and gives this to the chemical liquid pressure regulator, whereby the chemical liquid pressure in the chemical liquid supply path is adjusted. You. Further, the pure water flow rate operation amount adjustment means,
The pure water flow control amount is adjusted based on the target value set by the target value setting means, and is supplied to the pure water pressure regulator, whereby the pure water pressure in the pure water supply path is adjusted. As a result, the differential pressure between the chemical liquid pressure on the inlet side of the chemical liquid introduction valve and the pure water pressure on the outlet side is adjusted, and a chemical liquid having a flow rate according to the differential pressure is introduced into the pure water. A processing solution having a predetermined concentration obtained by mixing pure water and a chemical solution is sent to the substrate processing unit.

By the way, when two target values are determined among the chemical liquid flow target value, the pure water flow target value, and the treatment liquid concentration target value, the other target value is uniquely determined. Therefore,
The target value setting means sets two target values among the three target values. Then, by changing at least one of the two set target values over time, the efficiency of replacement when replacing the processing liquid in the substrate processing unit with a new processing liquid is increased, or the replacement is required. The processing liquid is saved, or the concentration unevenness of the processing liquid is suppressed.

The operation of the second aspect of the invention is as follows. According to the first aspect of the invention, when the pure water pressure in the pure water supply path is kept constant, the chemical liquid pressure in the chemical liquid supply path is adjusted by the chemical liquid pressure regulator, and thus the inlet side of the chemical liquid introduction valve is adjusted. A predetermined amount of the chemical solution was introduced into the pure water by adjusting the pressure difference between the chemical solution pressure and the pure water pressure on the outlet side. On the contrary,
According to the second aspect of the present invention, the chemical liquid flow rate in the chemical liquid supply path is directly controlled by operating the opening of the chemical liquid flow rate control valve based on the chemical liquid flow rate operation amount adjusted by the chemical liquid flow rate operation amount adjusting means. It is adjusted and a predetermined amount of chemical is introduced into pure water.
Other functions are the same as those of the first aspect of the present invention, and a description thereof will be omitted.

According to the third aspect of the present invention, the target value setting means sets the target value of the chemical liquid flow and the target value of the pure water flow. As a result, the target concentration of the processing liquid is uniquely determined.
The invention of claim 3 is particularly suitable for controlling the flow rate of the chemical solution and the flow rate of pure water.

The operation of the invention described in claim 4 is as follows. When the chemical liquid flow rate target value and the pure water flow rate target value are set to temporally constant values, specifically, the following problems occur. When a certain processing liquid is supplied to the substrate processing unit to perform the surface treatment of the substrate, and then the processing is performed with another processing liquid, first, pure water is supplied to the substrate processing unit, and the used water in the substrate processing unit is used. The treatment liquid is once replaced with pure water. Subsequently, a new processing liquid obtained by mixing pure water and a chemical solution is supplied, and the pure water in the substrate processing unit is replaced with the processing liquid. At this time, if the target value of the flow rate of the chemical solution and the target value of the pure water flow rate are small, the flow rate of the pure water supplied to the substrate processing unit for replacement or the flow rate of the processing liquid becomes small, and the inside of the substrate processing unit becomes new. The time until the replacement with the processing liquid is completed is prolonged, and the processing efficiency is reduced.
Conversely, setting the target value of the flow rate of the chemical or pure water to a large constant value is not preferable in terms of saving the processing liquid.

In order to solve the above problems, the invention according to claim 4 is to set both the target value of the chemical solution flow and the target value of the pure water flow at the initial stage of replacing the processing liquid in the substrate processing unit. After the replacement of the processing solution has progressed to some extent,
Each flow rate target value is reduced.

The operation of the invention described in claim 5 is as follows. If the chemical liquid flow rate target value and the pure water flow rate target value are set to temporally constant values, another problem as described below is expected. In the initial stage of replacement, in which the supply of a processing solution obtained by mixing a chemical solution and pure water into the substrate processing unit filled with pure water is started, the inside of the substrate processing unit is filled with pure water. In addition, it takes a long time to reach a desired concentration of the processing liquid in the substrate processing unit, and as a result, processing efficiency is reduced.

In order to solve such a problem, the invention according to claim 5 is to increase the ratio of the chemical solution flow rate to the pure water flow rate in the initial stage of the replacement when the supply of the processing solution is started. By supplying a processing liquid having a high concentration into the substrate processing unit, the rise of the average concentration of the processing liquid in the substrate processing unit is accelerated. Then, at the stage when the average concentration of the processing liquid in the substrate processing unit has increased to some extent, the flow rate of the chemical liquid is reduced,
A processing solution having a predetermined concentration is supplied to the substrate processing unit.

The operation of the invention described in claim 6 is as follows. When a high-concentration processing liquid is supplied to the substrate processing unit filled with pure water, the average concentration of the processing liquid in the substrate processing unit rises faster, but the processing liquid in the substrate processing unit tends to have uneven concentration. . In order to suppress such density unevenness, it is preferable to lower the concentration of the processing liquid supplied to the substrate processing unit in the initial stage of replacement. Then, claim 6
In the invention of the above, while the chemical solution flow rate target value is set to be constant, the initial target value of the pure water flow rate target value is set higher than the subsequent pure water flow rate target value, so that in the initial stage of replacement, the substrate processing unit The density of the processing liquid supplied to the processing liquid is reduced to suppress the occurrence of unevenness in the density of the processing liquid. When the replacement proceeds to some extent, the concentration of the processing liquid is increased to a predetermined concentration by lowering the target value of the pure water flow rate, and the processing liquid is supplied to the substrate processing unit.

According to the seventh aspect of the present invention, the target value setting means sets the target concentration of the treatment liquid and the target value of the pure water flow rate, and as a result, the chemical liquid flow rate target value is uniquely determined. The invention of claim 7 is particularly suitable when it is desired to control the concentration of the processing solution and the flow rate of pure water.

The operation of the invention of claim 8 is as follows. If the target concentration of the treatment liquid and the target value of the pure water flow rate are made constant over time, the following problems are specifically expected. If the pure water flow rate target value is constant over time, the chemical liquid flow rate is constant as long as the concentration target value is constant. As a result, a constant flow rate of the processing liquid is always supplied to the substrate processing unit. By supplying the processing liquid at a constant flow rate to the substrate processing unit filled with pure water, the average concentration of the processing liquid in the substrate processing unit gradually increases. As the average concentration of the processing liquid in the substrate processing unit approaches the desired concentration, the curve of the increase in the average concentration of the processing liquid in the substrate processing unit becomes gentler.
The processing liquid is continuously supplied to the substrate processing unit until the average concentration of the processing liquid in the substrate processing unit reaches the target concentration. During that time, excess processing liquid in the substrate processing section overflows and is discharged. That is, after the average concentration of the processing liquid in the substrate processing unit has increased to some extent, a constant amount of the processing liquid is supplied to the substrate processing unit even though the average concentration of the processing liquid in the substrate processing unit does not increase so much. Subsequently, since excess processing liquid is discharged, it can be said that the use efficiency of the processing liquid required for replacement is low.

In order to solve such a problem, the invention according to claim 8 keeps the target concentration of the processing solution constant over time, whereas the average concentration of the processing solution in the substrate processing section is reduced. As the concentration value approaches the target value, the pure water flow rate target value is reduced. Then, the flow rate of the chemical liquid is inevitably reduced, and the flow rate of the processing liquid supplied to the substrate processing unit is reduced, so that it is possible to prevent the processing liquid from being wastefully discharged.

According to the ninth aspect of the present invention, the target value setting means sets the target concentration of the treatment liquid and the target value of the chemical solution flow rate. As a result, the pure water flow rate target value is uniquely determined. The invention of claim 9 is particularly suitable when it is desired to control the concentration of the processing solution and the flow rate of the chemical solution.

The operation of the invention of claim 10 is as follows. If the target concentration of the treatment liquid and the target value of the chemical flow rate are set to constant values over time, the same disadvantages as described in the operation of the invention of claim 5 are expected. That is, if the target concentration of the treatment liquid and the target value of the chemical flow rate are set to constant values over time, the flow rate of the pure water will inevitably become constant over time.
It takes a long time to reach a desired concentration of the processing liquid in the substrate processing unit. In order to solve such a problem, in the invention according to claim 10, the target value of the chemical liquid flow rate is set to be constant over time, while the target concentration value is set high in the initial stage of the replacement when the supply of the processing liquid is started. I do. as a result,
Since the processing liquid having a high concentration is supplied into the substrate processing unit in the initial stage of the replacement, the rise of the average concentration of the processing liquid in the substrate processing unit is quickened. When the average concentration of the processing liquid in the substrate processing unit has increased to some extent, the target concentration of the processing liquid is returned to a desired target value.

The operation of the eleventh invention is as follows. In setting the target value, first, by the target value variable designating means, the type of the target value to be set from the chemical solution flow target value, the pure water flow target value, and the treatment liquid concentration target value, specifically, In addition to designating two types of target values, a variable for determining a pattern of temporal change of the specified target values is specified. The target value output means generates and outputs a time-varying target value based on the designated variable.

[0035]

Embodiments of the present invention will be described below with reference to the drawings. A: First Embodiment A1: Configuration of First Embodiment Apparatus A schematic configuration of a substrate processing apparatus according to the present embodiment will be described with reference to FIG. This substrate processing apparatus performs a surface treatment of a substrate W such as a semiconductor wafer with a processing liquid obtained by mixing pure water and a chemical solution. This substrate processing apparatus is roughly divided into a substrate processing tank 1 that is a substrate processing unit that stores a processing liquid and performs a surface treatment of the substrate W, and a processing liquid supply system that supplies the processing liquid to the substrate processing tank 1. And a control system for controlling the processing liquid supply system.

The substrate processing tank 1 is configured to receive the supply of the processing liquid from the bottom of the tank, and to discharge the excess processing liquid by overflowing. Usually, this type of substrate processing apparatus includes a plurality of substrate processing tanks 1 and each of the substrate processing tanks 1 is configured to be supplied with a processing liquid by an individual processing liquid supply system. However, for simplicity of description, a substrate processing apparatus having a single substrate processing tank 1 will be described as an example, but the present invention is not limited to a substrate processing apparatus having a plurality of substrate processing tanks 1. It can also be applied to devices.

A2: Configuration of the processing liquid supply system (particularly, pure water supply system) The processing liquid supply system is composed of a pure water supply system and a chemical liquid supply system. First, the pure water supply system will be described.
The substrate processing tank 1 and a pure water supply source are connected by a pure water supply path 2. The pure water supply path 2 is provided with a pure water pressure regulator 3, a pure water flow sensor 4, and a chemical solution mixing section 5 in this order from the pure water supply source side. The pure water pressure regulator 3 is provided with an air pressure (hereinafter referred to as a pilot pressure) given from the electropneumatic converter 6.
Is a control valve that adjusts the pure water pressure on the secondary side of the pure water pressure regulator 3 according to.

More specifically, the pure water pressure regulator 3 has a valve body interlocked with the diaphragm inside. Pilot pressure acts on one surface of the diaphragm, and pure water pressure on the secondary side acts on the other surface. If there is a pressure difference between the two pressures, the diaphragm is deformed and the opening of the valve body changes. When both pressures are balanced, the valve body stops. That is, the valve element is displaced such that the pure water pressure on the secondary side of the pure water pressure regulator 3 is balanced with the pilot pressure. Therefore, by providing a constant pilot pressure, the pure water pressure on the secondary side of the pure water pressure regulator 3 can be made constant. As a result, the flow rate of pure water flowing through the pure water supply path 2 can be kept constant as long as the flow path resistance of the pure water supply path 2 on the secondary side of the pure water pressure regulator 3 does not change.

The electropneumatic converter 6 converts the supplied pressurized air (pressurized air) into an air pressure (pilot pressure) corresponding to an operation voltage from a control system described later and outputs the same. The pure water flow sensor 4 detects the flow of pure water flowing through the pure water supply path 2.
The pure water flow detection signal (current pure water flow value b2) is provided to a control system described later. Further, the pure water supply path 2 is provided with a pure water pressure sensor 7 for detecting the pressure of pure water flowing therethrough. The pure water pressure detection signal (current pure water pressure value e2) is given to a control system described later.

The chemical mixing section 5 has a pure water supply valve 8 for opening and closing the pure water supply passage 2 and a plurality of chemical introduction valves for individually introducing different kinds of chemicals into the pure water of the pure water supply passage 2. 9 and a liquid supply path 1 connected to the outlet side of each liquid introduction valve 9.
And a chemical supply valve 10 that opens and closes the valve 1.

FIG. 2 shows the structure of the chemical liquid introduction valve, which also has the function of the chemical liquid supply valve 10. Chemical introduction valve 9
As shown in FIG. 2, is connected to an introduction valve connection pipe 12 provided in the middle of the pure water supply path 2. A valve chamber 9a is formed by combining the bottom surface of the chemical solution introduction valve 9 and a bottomed hole drilled in the introduction valve connecting pipe 12. The valve chamber 9a is connected to the chemical solution supply path 11 through a connection hole 9b. The valve chamber 9a is connected to a pure water flow path 12a of the introduction valve connecting pipe 12 through a chemical solution introduction port 9g. In the valve chamber 9a,
A throttle valve 9c for opening and closing the chemical solution inlet 9g and adjusting the opening degree is provided. The base end of the throttle valve 9c is connected and supported by a support 9e that slides and displaces inside the valve body 9d. The support 9e is pressed downward by a spring 9h. In a state where air is not supplied to the pilot air supply port 9i, the support pair 9e and the throttle valve 9c are pressed downward by the spring force of the spring 9h, and at this time, the chemical liquid introduction port 9g is closed. In a state where air is supplied to the pilot air supply port 9i, the support 9e and the throttle valve 9c rise by virtue of the spring force of the spring 9h, and come into contact with the tip of the adjusting bolt 9f screwed into the valve body 9d. Stop. In this state, the liquid inlet 9g is open. By manually adjusting the screwing amount of the adjusting bolt 9f, the throttle valve 9c and the adjusting bolt 9f are brought into contact with each other, and the degree of opening of the chemical solution inlet 9g is adjusted. According to the chemical liquid introduction valve 9, the pressure of the pure water flowing through the pure water flow path 12a on the outlet side is increased by the pressure of the chemical liquid supply path 1 on the inlet side.
By setting each pressure to be lower than the pressure of the chemical solution flowing through 1, the chemical solution having a flow rate corresponding to the differential pressure between the chemical solution pressure on the inlet side and the pure water pressure on the outlet side flows through the pure water flow path 12a. Introduced into pure water.

A3: Configuration of Processing Liquid Supply System (Especially, Chemical Liquid Supply System) A number of chemical liquid supply systems are provided according to the type of processing liquid used in the present apparatus. It is connected to each chemical solution introduction valve 9. Since each chemical solution supply system has the same configuration, one chemical solution supply system illustrated in FIG. 1 will be described below.

One end of the chemical supply path 11 is introduced into the chemical in the chemical tank 13. The chemical tank 13 is pressure-resistant,
And it has a closed structure. A gas supply path 14 is introduced into an upper space in the chemical liquid tank 13. A pressurized inert gas (here, nitrogen gas) is introduced into the chemical liquid tank 13 through the gas supply path 14. The gas supply path 14 is provided with a gas pressure regulator 15 for adjusting the gas pressure on the secondary side. The gas pressure adjuster 15 adjusts the gas pressure on the secondary side according to the pilot pressure given from the electropneumatic converter 16. The electropneumatic converter 16 is provided with a gas pressure setting voltage for setting the pressure of the nitrogen gas in the chemical liquid tank 13 to a constant value. With the above configuration, the nitrogen gas of a constant pressure corresponding to the gas pressure set voltage is introduced into the chemical tank 13 so that the chemical tank 13
The liquid medicine in the inside is pressurized, and the liquid medicine at a constant pressure is supplied to the liquid supply path 11.
To be pumped. The above-described gas supply path 14, gas pressure regulator 15, and electropneumatic converter 16 correspond to a chemical solution pumping unit in the present invention.

A filter 1 for removing particles in the chemical solution is sequentially provided from the chemical solution tank 13 to the chemical solution supply path 11.
7. A chemical liquid flow sensor 18 for detecting a chemical liquid flow rate, and a chemical liquid pressure regulator 19 for adjusting the chemical liquid pressure on the secondary side are provided. The secondary side of this chemical liquid pressure regulator 19 is connected to the above-mentioned chemical liquid introduction valve 9. The chemical liquid flow rate detection signal (current chemical liquid flow value b1) of the chemical liquid flow sensor 18 is given to a control system described later. The chemical liquid pressure regulator 19 is a control valve having a configuration similar to that of the above-described pure water pressure regulator 3, and adjusts the secondary-side chemical liquid pressure according to the pilot pressure given from the electropneumatic converter 20. I do. The electropneumatic converter 20 outputs a pilot pressure according to an operation voltage from a control system described later.

A4: Schematic Configuration of Control System The control system is composed of computer equipment. This control system is functionally distinguished from the target value setting unit 30.
A, chemical solution concentration feedback control unit 40A, current concentration value calculation unit 5
0, a pure water pressure fluctuation feedback section 60A, and a pure water flow rate feedback control section 70. As will be apparent from the description below, the target value setting unit 30A of the present embodiment includes a chemical concentration feedback control unit 40A as a target value setting unit in the present invention.
The pure water pressure fluctuation feedback section 60A corresponds to the chemical liquid flow rate operation amount adjusting means in the present invention, and the pure water flow rate feedback control section 70 corresponds to the pure water flow rate operation amount adjusting means in the present invention. FIG. 3 is a block diagram showing only the control system of the present embodiment. Hereinafter, description will be made with reference to FIG.

The target value setting section 30A is for setting a target value of the control amount. In the case of a substrate processing apparatus, the goal is to finally bring the concentration of the processing solution to a desired concentration. Since this processing liquid is generated by mixing pure water and a chemical liquid, when the pure water flow rate and the chemical liquid flow rate are determined, the concentration of the processing liquid is uniquely determined. Therefore, it is not always necessary to select the concentration of the processing liquid as the control amount. That is, any two of the processing solution concentration, the chemical solution flow rate, and the pure water flow rate may be set as the control amount. What to select as the control amount is determined by the item to be managed. In the present embodiment, a chemical solution flow rate and a pure water flow rate are used as control amounts. The target value setting unit 30A sets each target value of the chemical liquid flow rate and the pure water flow rate as the control amounts.

Further, the target value setting section 30A sets a chemical solution flow target value and a pure water flow target value which change with time. Since the concentration of the processing liquid used for the substrate processing is a constant value, in that sense, it is conceivable to make the target value of the control amount constant over time. However, when the replacement of the processing liquid in the substrate processing tank 1 is performed efficiently, the processing liquid required for the replacement is reduced, or the concentration unevenness of the processing liquid in the substrate processing tank 1 is suppressed, which will be described later. As will be clear from the description, it is preferable to change the target value over time.

As shown in FIG. 3, the target value setting section 30A
Is composed of a variable designation unit 31 and a target value output unit 32. The variable specifying unit 31 is for specifying the type of the target value to be set and for specifying the variable for determining the change pattern of the specified target value. The target value output unit 32 outputs a target value that changes with the passage of time, here, a chemical liquid flow target value and a pure water flow target value, based on a variable specified via the variable specifying unit 31.

The chemical liquid concentration feedback control section 40A is a processing liquid concentration target value a3 uniquely determined from the chemical liquid flow target value a1 and the pure water flow target value a2 set by the target value setting section 30A.
Further, a concentration deviation c3 between the target concentration value a3 and the present concentration value b3 of the processing liquid is determined, and the chemical liquid flow rate operation amount d1 is adjusted so as to cancel the concentration deviation c3. The chemical liquid flow rate operation amount d1 is converted into a chemical liquid flow rate operation voltage Vd1 and provided to the pure water pressure fluctuation feedback unit 60A.

The current concentration value calculating section 50 calculates the current concentration value of the processing solution from the current pure water flow value b2 detected by the pure water flow sensor 4 and the current chemical solution flow value b1 detected by the chemical solution flow sensor 18. b3 is calculated. The current concentration value b3 is provided to the chemical concentration feedback control unit 40A.

[0051] Pure water pressure fluctuation feedback section 60A, when pure water pressure current value e2 detected by the pure water pressure sensor 7, is higher than the pure water pressure reference value P _0, which is determined in advance, chemical pressure Is corrected in a direction to increase the pressure, and conversely, when the present pure water pressure value e2 becomes lower than the pure water pressure reference value P ₀ , the chemical flow operation voltage Vd1 is decreased in the direction to lower the chemical pressure. Vd1 is corrected. The thus-corrected chemical flow rate operation voltage Vd1 ′ is supplied to the electropneumatic converter 20.

The pure water flow rate feedback control section 70 calculates a deviation c2 between the pure water flow rate target value a2 set by the target value setting section 30A and the pure water flow rate current value b2 detected by the pure water flow rate sensor 4. Then, a pure water flow operation amount d2 that cancels out the pure water flow deviation c2 is calculated. The pure water flow rate operation amount d2 is converted into a pure water flow rate operation voltage Vd2, and provided to the electropneumatic converter 6.

A5: Operation of Example Apparatus (1) Setting of Target Value First, the operator operates the variable specifying section 31 to determine the type of the target value (in this embodiment, the target value of the chemical flow rate a1 and the target of the pure water flow rate). A value a2) is specified, and a variable for determining a change pattern of these target values is specified. Based on these designations, the target value output unit 32 outputs a chemical solution flow target value a1 and a pure water flow target value a2 that change over time.

The process of setting a temporally changing target value will be described below in detail with reference to FIGS. Regardless of the target value of the chemical flow rate, the target value of the pure water flow rate, or the target value of the concentration of the processing liquid, the process of setting the target value is executed in the same manner, and therefore, hereinafter, it is simply referred to as “target value”. .

First, a change pattern of the target value and variables for determining the change pattern will be described with reference to FIG. FIG. 4 shows an example of a change pattern of the target value, in which time is assigned to the horizontal axis and the value of the target value is assigned to the vertical axis. The change pattern of the target value is specified by a combination of some flat portions (constant value regions) and gradient portions (change regions). However, for convenience of control, the target at the start of control (at the start of introduction of the chemical solution into pure water) and at the end of control (at the time when the replacement of the processing solution in the substrate processing tank 1 is completed and the supply of the processing solution is stopped) The value is set to a fixed value.

The following four types of variables are specified by the operator for determining the change pattern of the target value. Number of states n: Numerical value representing the number of times the target value changes between the start of control and the end of control. Target value constant values Qref (1) to Qref (n + 1): These are the respective values of the flat portion in the change pattern of the target value. Change times Tchg (1) to Tchg (n): Times from the start of control to the end of each flat portion in the target value change pattern. Required change time Tchgs (1) to Tchgs (n): The required time from the end of the flat portion in the change pattern of the target value to the start of the next flat portion, that is, the time of each gradient portion.

In addition to the variables specified by the operator, there are the following variables calculated or set in advance in the process of setting a target value, which will be described later. Sampling time ts: an output interval of the target value output from the target value output unit 32 every moment, which is preset to, for example, 0.1 second in this embodiment. Target value increments ΔQ (1) to ΔQ (n): increments of the target value per sampling, which are calculated in the setting process. -Time counter tcount: "1" for each sampling time
Is a count value that increases only by State number stat: Numerical value indicating the state of the change pattern of the target value, which changes from “1” to “1 + n” (see FIG. 4).

Next, the process of setting the target value will be described with reference to FIGS. The target value setting process is divided into a pre-process for specifying the above-described variables and the like, and a target value output process for outputting a target value that changes with time according to these variables. First, the preprocessing process will be described with reference to the flowchart of FIG.

Step S1: The operator specifies the variable specifying unit 3
By operating 1, the type of the target value is designated. As the target value, two target values of the chemical liquid flow target value, the pure water flow target value, and the treatment liquid concentration target value are designated. In particular, in the first embodiment, a chemical liquid flow rate target value and a pure water flow rate target value are specified.

Step S2: Four kinds of variables for determining the change pattern of the target value, that is, the number n of states, the constant values Qref (1) to Qref (n + 1) of the target value, and the change time Tchg (1) ~
Tchg (n) and the required change times Tchgs (1) to Tchgs (n) are designated.

Step S3: Based on the variables specified in step S2, the increments ΔQ (1) to ΔQ (n) of the target value per sampling are calculated by the following equation. ΔQ (1) = (Qref (2) −Qref (1)) / (Tchgs (1) / t
s) ΔQ (2) = (Qref (3) −Qref (2)) / (Tchgs (2) / t
s)... ΔQ (n) = (Qref (n + 1) −Qref (n)) / (Tchgs (n) /
ts)

Step S4: Other variables are initialized. Specifically, the time counter tcount is set to "0", and the constant value Qref of the target value is set to "Qref (1)".

The processes in steps S2 to S4 described above are
This is performed for each specified target value. After the above pre-processing process is executed only once before the output process of the target value, the process proceeds to the output process of the target value. In the process of outputting the target value, the process shown in the flowchart of FIG. 6 is repeatedly executed for each preset sampling time ts from the start of control to the end of control. Hereinafter, each process will be specifically described.

Step T1: “1” is set to the status number stat. Step T2: The sum of the time (tcount × ts) from the control start time to the present time, the change time Tchg (stat) and the required change time Tchgs (stat) (Tchg (stat) + Tchgs (sta)
t)) to determine the state of the change pattern of the target value (whether the state number stat should be changed to output a new constant value Qref of the target value). That is, tc
If ount × ts <Tchg (stat) + Tchgs (stat), it is determined that the state number stat is maintained, and the process proceeds to step T3. On the other hand, tcount × ts ≧ Tchg (stat) + Tchgs (sta
If t), it is determined that the state number stat is to be changed, and the process proceeds to step T7.

Step T3: It is determined whether the current target value is in the constant value range of the change pattern of the target value or in the change range. Specifically, the time (tcount × ts) from the start of control to the present is the change time Tchg (sta
If it is smaller than t), it is determined that it is in the fixed value range, and the process proceeds to step T4. On the other hand, if tcount × ts is equal to or greater than Tchg (stat), it is determined that the target value is in the change range of the conversion pattern, and the process proceeds to step T5.

Step T4: Constant value Qref (stat) of target value
And the process proceeds to step T6. Step T5: increment ΔQ of the target value to the current target value Qref
The value to which (stat) has been added is output as a new target value Qref, and the process proceeds to step T6. Step T6: Target value Qref in step T4 or T5
Is output, the time counter tcount is incremented by "1".

Step T7: In the above-described step T2,
If it is determined that the state number stat is to be changed, the state number stat is incremented by "1", and the process proceeds to step T8. Step T8: The status number stat is changed to the final status number “n +
1 "is determined. If the state number stat is equal to or smaller than "n", the process returns to step T2, and repeats the processing of steps T2 to T6.
On the other hand, the state number stat is larger than “n” (ie,
If the state number stat is “n + 1”), step T
4 and the target constant value Qref (stat) (in this case, Q
ref (n + 1)), and then proceeds to step T6.

By repeatedly executing the above-described output process of the target value, the target value obtained in step T4 or T5 is changed to the sampling time (0.1 second in this embodiment).
Is output every time.

The target value setting process described above is performed for each processing solution when the substrate is processed using a plurality of types of processing solutions in order. When the supply of the processing liquid to the substrate processing tank 1 is started, the substrate processing tank 1 is filled with pure water. This means that after processing the substrate using a certain processing solution,
The same applies when the substrate is processed with the next processing liquid. That is, when the processing of the substrate is finished using a certain processing liquid, only the pure water is supplied to the substrate processing tank 1, and the used processing liquid in the substrate processing tank 1 is once replaced with pure water. Subsequently, in a state where pure water is supplied to the substrate processing tank 1, by starting introduction of a chemical solution into the pure water, a new processing liquid is supplied to the substrate processing tank 1, and Of pure water is replaced with a new treatment liquid. Hereinafter, a state in which pure water is continuously supplied and the substrate processing tank 1 is filled with pure water is referred to as an initial state of replacement, and from this state, a chemical solution is introduced into pure water in the pure water supply path 2. The description will be made on the assumption that the time point is the time point at which the supply of the processing liquid to the substrate processing tank 1 is started (the time point at which the above-described control is started).

(2) Operation of Chemical Solution Concentration Feedback Control Unit 40A Based on the chemical solution flow target value a1 and the pure water flow target value a2, the target concentration value calculation unit 41 calculates the target concentration a3 of the processing liquid. Specifically, the target concentration a3 of the processing liquid is calculated by the following equation (1). a3 = (a1 × C ₀ ) / (1000 × a2 + a1) (1) where a1 is the target value of chemical liquid flow [cc / min] a2 is the target value of pure water flow [liter / min] a3 is processing Solution concentration target value [%] C ₀ is the concentration of drug substance solution [%]

The calculated processing solution concentration target value a 3 is given to the subtractor 42 and the adder 45. On the other hand, the current concentration value calculation section 50 calculates the current concentration value b3 of the treatment liquid from the current chemical solution flow value b1 given from the chemical solution flow sensor 18 and the pure water flow current value b2 given from the pure water flow sensor 4. Is calculated by the following equation (2). The calculated current concentration b3 of the processing liquid is supplied to the subtractor 42. b3 = b1 × C ₀ / (1000 × b2 + b1) (2) where b1 is the current value of the chemical flow rate [cc / min] b2 is the current value of the pure water flow rate [liter / min] b3 is the Concentration current value [%] C ₀ is the concentration of drug substance solution [%]

The subtracter 42 subtracts the current concentration b3 of the processing liquid from the target concentration a3 of the processing liquid calculated by the target concentration calculating section 41 to thereby obtain the concentration deviation c3 of the processing liquid.
Ask for. This density deviation c3 is given to the PII ² D calculation unit 43.

The PII ² D calculation section 43 performs a proportional operation (P operation) for determining the concentration manipulated variable in proportion to the concentration deviation c3 of the processing liquid given from the subtractor 42, and a proportional operation to the integration of the concentration deviation c3. Operation (I operation) to determine the concentration manipulated variable by
When, the double integration operation to determine the concentration operation amount in proportion to the double integral of the density deviation c3 (I ² operation), the differential operation of determining the concentration operation amount is proportional to the derivative of the density deviation c3 (D operation) Is calculated according to the control law including the above. This manipulated variable for density control is provided to an adder 45 via a switch 44.

The adder 45 adds the concentration control operation amount of the processing liquid given from the PII ² D calculation unit 43 via the switch 44 to the concentration target value a3 of the treatment liquid given from the concentration target value calculation unit 41. to add. The concentration manipulated variable d3 of the processing liquid obtained by adding the concentration target value a3 and the concentration control manipulated variable is given to the concentration-flow rate converter 46.

The switch 44 is connected to the pure water in the pure water supply path 2.
OFF state for a certain period of time from the beginning of the introduction of the chemical
Become a PII^TwoThe output of the D operation unit 43 is prohibited (PI
I^TwoD operation unit 43 is deactivated), and after a predetermined time elapses, O
Switch to N state and PII ^TwoAllow the output of D operation unit 43
(PII^TwoThe D operation unit 43 is operated). like this
The reason for providing the switch 44 is as follows.

Following the initial state of replacement in which the pure water supply valve 8 is opened and pure water flows through the pure water supply path 2, the chemical supply valve 10 is opened and the chemical flows through the chemical supply path 11. At the beginning of the start of the supply of the treatment liquid, the rising of the chemical liquid flow rate in the chemical liquid supply path 11 is slow, so the current chemical liquid flow value b1 detected by the chemical liquid flow sensor 18 shows a value considerably lower than the target value. As a result, the current concentration b3 of the processing liquid output from the current concentration calculation unit 50 is considerably reduced, and the concentration deviation c3 is increased. In an attempt to cancel the density deviation c3, the PII ² D calculation unit 43 outputs a large density control operation amount. Therefore, the so-called overshoot occurs in which the concentration manipulation amount of the processing liquid becomes too large, and an excessive chemical solution is introduced into pure water. A switch 44 is provided to avoid such an overshoot at the beginning of the supply of the processing liquid, and the concentration of the processing liquid is controlled only by the target concentration a3 of the processing liquid at the beginning of the supply of the processing liquid. . In the present embodiment, the switch 44 is controlled by a program timer, but the switch 44 may be switched according to the value of the concentration deviation c3 of the processing liquid.

The concentration-flow rate conversion section 46 converts the concentration manipulated variable d3 of the processing liquid into the chemical fluid flow manipulated variable d1. For this conversion, the concentration-flow rate converter 46 sets the pure water flow rate target value a
2. The reason is as follows. In the case of the present embodiment, since the pure water flow rate in the pure water supply path 2 is controlled by the pure water flow rate feedback control unit 70, the fluctuation of the pure water flow rate is small. Therefore, in the steady state where the flow rate of the chemical in the chemical supply path 11 is stable, the concentration control of the processing liquid can be performed more stably by using the pure water flow rate target value a2.

The concentration-flow rate converter 46 obtains the chemical liquid flow rate operation amount d1 by the following equation (3). d1 = 1000 × d3 × a2 / (C ₀ −d3) (3) where a2 is the pure water flow rate target value [liter / min] d1 is the chemical liquid flow rate operation amount [cc / min] d3 is the processing Liquid concentration operation amount [%] C ₀ is the concentration of drug substance solution [%]

This chemical liquid flow rate operation amount d1 is given to the flow rate-voltage conversion unit 47. The flow rate-voltage converter 47 converts the chemical liquid flow operation amount d1 into a chemical liquid flow operation voltage Vd1 to be applied to the electropneumatic converter 20 according to the following equation (4). Vd1 = d1 × Ac + Bc (4) where Vd1 is the chemical liquid flow operation voltage [V] d1 is the chemical liquid flow operation amount [cc / min] Ac is each of the electropneumatic converter 20 and the chemical liquid pressure regulator 19 The constant Bc determined by the specification and the valve opening of the chemical liquid introduction valve 9 is a constant determined by the pure water pressure reference value P ₀ and the specification of the chemical liquid pressure regulator 19. The above constants Ac and Bc can be obtained by experiments.

As described above, the chemical concentration feedback control section 40A
Is set by adjusting the chemical liquid flow rate operation amount d1 so as to cancel the deviation c3 between the target concentration a3 of the processing liquid and the current concentration b3. Even if the chemical solution introduction valve 9 undergoes thermal deformation due to the flow of water, the concentration of the treatment solution fluctuates quickly even if the amount of the chemical solution introduced into pure water changes and the concentration of the treatment solution fluctuates. can do.

(3) Operation of the Pure Water Pressure Fluctuation Feedback Unit 60A The subtracter 61 of the pure water pressure fluctuation feedback unit 60A determines a predetermined pure water pressure value from the pure water pressure current value e2 detected by the pure water pressure sensor 7. By subtracting the water pressure reference value P ₀ , a pressure fluctuation value Δe2 of the pure water pressure current value e2 is obtained. The pure water pressure reference value P ₀ is determined by experimentally obtaining the pure water pressure when a reference amount of pure water flows through the pure water supply path 2.

The pressure fluctuation value Δe2 obtained by the subtractor 61 is given to the pressure-voltage converter 62. The pressure-voltage converter 62 converts the pressure fluctuation value Δe2 into a voltage ΔVe2 for correcting the chemical liquid flow rate operation voltage Vd1 by using a linear equation experimentally obtained in relation to the specifications of the electropneumatic converter 20 and the like. Convert. The corrected chemical flow rate operation voltage Vd1 ′ is obtained by adding the chemical flow rate operation voltage Vd1 output from the chemical concentration feedback control unit 40A and the correction voltage ΔVe2 by the adder 63. This chemical liquid flow operation voltage Vd
1 ′ is provided to the electropneumatic converter 20. The electropneumatic converter 20 provides the pilot pressure according to the chemical flow rate operation voltage Vd1 'to the chemical pressure regulator 19. The chemical liquid pressure regulator 19 adjusts the chemical liquid pressure (as a result, the chemical liquid flow rate) in the secondary chemical liquid supply passage 11 so as to match the pilot pressure.

When the pure water pressure in the pure water supply path 2 fluctuates, the pure water pressure fluctuation feedback section 60A changes the chemical liquid flow rate operation voltage Vd1 following the pressure fluctuation. as a result,
When the pure water pressure in the pure water supply path 2 increases, the chemical liquid pressure in the chemical liquid supply path 11 increases accordingly, and conversely, when the pure water pressure decreases, the chemical liquid pressure decreases accordingly. That is, since the pressure of the pure water in the pure water supply path 2 fluctuates and the pressure difference between the chemical liquid pressure on the inlet side and the pure water pressure on the outlet side of the chemical liquid introducing valve 9 changes, the pure water pressure is introduced into the pure water. Even if the flow rate of the chemical solution fluctuates, the pressure of the chemical solution in the chemical solution supply passage 11 is quickly adjusted to return the differential pressure between the inlet side and the outlet side of the chemical solution introduction valve 9 to a predetermined value. The resulting fluctuation in the concentration of the processing solution can be suppressed.

Even if the pure water pressure fluctuation feedback section 60A is not provided, if the concentration of the processing liquid fluctuates due to the fluctuation of the pure water pressure, the above-mentioned chemical liquid concentration feedback control section 40A operates to operate the processing liquid liquid. The chemical solution flow operation voltage Vd1 is adjusted so that the concentration returns to the target value. However, after the pure water pressure fluctuates,
There is a delay until the fluctuation in the concentration of the processing solution is detected.
On the other hand, if the pure water pressure fluctuation feedback unit 60A is provided, when the pure water pressure fluctuation occurs, the chemical liquid flow rate operation voltage Vd1 is immediately corrected regardless of the presence or absence of the concentration of the processing liquid. Can be quickly suppressed.

(4) Operation of the pure water flow rate feedback control unit 70 The subtracter 71 of the pure water flow rate feedback control unit 70 calculates the pure water flow rate sensor 4 from the pure water flow rate target value a2 set by the target value setting unit 30A. The pure water flow deviation c2 is calculated by subtracting the present pure water flow value b2 detected in step (1). The pure water flow rate deviation c2 is given to the PID calculation unit 72. The PID calculation unit 72 calculates the pure water flow rate deviation c2 given from the subtractor 71.
Proportional operation (P operation) for determining the pure water flow operation amount in proportion to the integral water operation (I operation) for determining the pure water flow operation amount in proportion to the integral of the pure water flow deviation c2; Deviation c
And a differential operation (D operation) for determining a pure water flow manipulated variable in proportion to the derivative of 2.
Is calculated as a pure water flow control operation amount that cancels out. The operation amount of the pure water flow control is added to an adder 74 via a switch 73.
Given to.

The switch 73 is turned off for a certain period of time from the point when the pure water supply valve 8 is opened and the pure water starts flowing through the pure water supply path 2 to inhibit the output of the PID calculation unit 72. (The PID calculation unit 72 is deactivated.) After a certain time has elapsed, the state is switched to the ON state, and the output of the PID calculation unit 72 is permitted (the PID calculation unit 72 is activated). The switch 73 is provided to avoid an overshoot in the initial stage when pure water starts flowing to the pure water supply path 2, similarly to the switch 44 described in the chemical concentration feedback control unit 40 </ b> A.

The adder 74 adds the pure water flow control operation amount given from the PID calculation unit 72 via the switch 73 to the pure water flow target value a2 given from the target value setting unit 30A. The pure water flow operation amount d2 obtained by adding the pure water flow target value a2 and the pure water flow control operation amount is given to the flow-voltage converter 75.

The flow rate-voltage conversion section 75 calculates the pure water flow rate operation amount d2 given from the adder 74 based on the following equation (5).
It is converted to the pure water flow operation voltage Vd2. Vd2 = (d2-Cc) / Dc (5) Here, Vd2 is a pure water flow operation voltage [V] d2 is a pure water flow operation amount [liter / min] Cc and Dc are electropneumatic converters 6 And the constants determined by the specifications of the pure water pressure regulator 3 and the resistance coefficient of the pure water supply path 2 The above constants Cc and Dc can be obtained by experiments.

The pure water flow control voltage Vd 2 is supplied to the electropneumatic converter 6. The electropneumatic converter 6 operates at a pure water flow rate operation voltage Vd.
2 is provided to the pure water pressure controller 3.
The pure water pressure adjuster 3 adjusts the pure water pressure (as a result, the pure water flow rate) in the secondary-side pure water supply path 2 so as to match the pilot pressure.

The pure water flow rate feedback controller 70 calculates a pure water flow manipulated variable d2 that cancels the deviation c2 between the pure water flow target value a2 and the pure water flow present value b2, and calculates the pure water flow manipulated variable. Since the pure water flow rate in the pure water supply path 2 is controlled by adjusting the pure water pressure regulator 3 based on d2, it is possible to suppress the concentration fluctuation of the processing solution caused by the pure water flow fluctuation. it can. Even if the pure water flow rate feedback control unit 70 is not provided, if the concentration of the processing liquid fluctuates due to the fluctuation of the pure water flow rate, the above-mentioned chemical liquid concentration feedback control unit 40A operates to set the concentration of the processing liquid to the target value. Is adjusted so as to return to. However, after the pure water flow fluctuates,
There is a delay until the fluctuation in the concentration of the processing solution is detected.
On the other hand, when the pure water flow rate feedback control unit 70 is provided, when the pure water flow rate fluctuation occurs, the pure water flow rate operation amount d2 is immediately adjusted regardless of the presence or absence of the processing liquid concentration fluctuation. The effect of the fluctuation can be suppressed promptly.

As described above, according to the first embodiment described above, the chemical solution flow target value a1 and the pure water flow target value a2, each of which changes with the passage of time, are set. Sets the chemical liquid flow operation voltage Vd1 so as to suppress the concentration fluctuation of the processing liquid. On the other hand, the pure water pressure fluctuation feedback unit 60A corrects the set chemical liquid flow operation voltage Vd1 according to the fluctuation of the pure water pressure. Further, the pure water flow rate feedback control unit 70 adjusts the pure water flow rate operation voltage Vd2 so as to suppress the fluctuation of the pure water flow rate. Therefore, according to the present embodiment, the concentration of the processing liquid can be accurately and quickly made to match the target value.

A6: Variation Pattern of Target Value Three examples of temporal variation patterns of the chemical liquid flow rate target value a1 and the pure water flow rate target value a2 will be described below. (1) Please refer to FIG. In this example, the target value setting unit 30
A is from the point in time when the supply of the processing liquid to the substrate processing tank 1 filled with pure water is started (at the start of control) to the point in time when the inside of the substrate processing tank 1 is replaced with the processing liquid (the end of control). During this period, the initial target values of the chemical solution flow target value a1 and the pure water flow target value a2 are set higher than the subsequent target values. Since the ratio of the chemical solution flow target value a1 to the pure water flow target value a2 is constant over time, when the chemical solution flow target value a1 and the pure water flow target value a2 are set, the concentration of the treatment liquid that is uniquely determined The target value a3 also becomes constant over time. According to this example, since a large amount of the processing liquid is supplied to the substrate processing tank 1 in the initial stage of the replacement of the substrate processing tank 1, the speed at which the pure water in the substrate processing tank 1 is replaced with the processing liquid increases. , The processing efficiency of the replacement can be increased.

(2) Referring to FIG. In this example, the target value setting unit 30A includes the substrate processing tank 1 filled with pure water.
The initial target value of the chemical liquid flow rate target value a1 is changed from the time when the supply of the processing liquid is started to the time when the inside of the substrate processing tank 1 is replaced with the processing liquid to the subsequent chemical liquid flow rate target value a1.
In addition, since the target value a2 of the pure water flow rate is set to be constant, the target concentration value a3 of the processing liquid in the initial stage of the replacement becomes higher. In other words, since the processing liquid having a high concentration is supplied to the substrate processing tank 1 in the initial stage of the replacement, the rise of the average concentration of the processing liquid in the substrate processing tank 1 initially filled with pure water is quickened. When the average concentration of the processing liquid in the substrate processing tank 1 has increased to some extent, the processing liquid having a predetermined concentration is supplied to the substrate processing tank 1 by returning the target value a1 of the chemical solution flow rate to a predetermined target value. According to this example, since the rise of the average concentration of the processing liquid in the substrate processing tank 1 is fast, the processing efficiency of the replacement can be increased.

(3) Referring to FIG. In this example, the target value setting unit 30A includes the substrate processing tank 1 filled with pure water.
While the supply of the processing liquid into the substrate processing tank is started and until the inside of the substrate processing bath 1 is replaced with the processing liquid, the chemical liquid flow rate target value a1 is set to be temporally constant, while the pure water flow rate target value a2 is set. Is set higher than the subsequent pure water flow rate target value. That is, in the initial stage of the replacement, a processing liquid having a low concentration is supplied to the substrate processing tank 1, and when the average concentration of the processing liquid in the substrate processing tank 1 has increased to some extent, the pure water flow rate target value a2 is returned to a predetermined value. Then, a processing solution having a predetermined concentration is supplied to the substrate processing tank 1. If such a target value is set, a processing liquid having a low concentration is supplied into the substrate processing tank 1 filled with pure water in the initial stage of replacement, so that the average concentration of the processing liquid in the substrate processing tank 1 is increased. Can be kept small.
In the graph showing the change in the concentration unevenness of the processing liquid in the substrate processing tank 1 in FIG. , Respectively.

A7: Modifications (1) The current concentration b3 of the processing solution may be measured by a concentration measuring device. Although not shown, this concentration measuring device is provided in the pure water supply path 2 on the outlet side of the chemical solution mixing section 5 in FIG. However, since the concentration measuring device is generally expensive, if the current concentration b3 of the processing liquid is obtained by calculation as in the above-described embodiment, this type of substrate processing apparatus can be realized at low cost.

(2) The chemical liquid flow rate operation amount adjusting means in the present invention is not necessarily a chemical liquid concentration feedback control unit 4 as described above.
It is not necessary to be composed of 0A and the pure water pressure fluctuation feedback section 60A. For example, the chemical flow rate operation voltage Vd1 obtained by the chemical concentration feedback control unit 40A may be directly supplied to the electropneumatic converter 20. Alternatively, the chemical liquid flow rate operation voltage Vd1 corresponding to the chemical liquid flow rate target value a1 may be output from the target value setting unit 30A, and may be directly supplied to the pure water pressure fluctuation feedback unit 60A.

(3) The pure water pressure fluctuation feedback section 60A is provided with a pure water pressure current value calculating section for calculating the pure water pressure current value e2 based on the detection signal of the pure water flow rate sensor 4, and the calculated pure water pressure The deviation Δe2 may be determined from the current value e2 and the pure water pressure reference value P ₀ .

B: Second Embodiment B1: Configuration of Second Embodiment Apparatus In the substrate processing apparatus according to the present embodiment, the configurations of a pure water supply system and a chemical solution supply system to the substrate processing tank 1 are shown in FIG. Since it is the same as that of the first embodiment (see the above-mentioned items A1 to A3), the description is omitted here.

B4: Schematic Configuration of Control System FIG. 10 shows the configuration of the control system of the apparatus of this embodiment. This control system is functionally distinguished from a target value setting unit 30B, a chemical concentration feedback control unit 40B, a current concentration value calculation unit 50, a pure water pressure fluctuation feedback unit 60A, and a pure water flow rate feedback control unit 70. ing. Among them, the current concentration value calculation unit 50,
Each configuration of the pure water pressure fluctuation feedback section 60A and the pure water flow rate feedback control section 70 is the same as that of the first embodiment (the above item A4).
), And the description is omitted here.
Hereinafter, portions different from the first embodiment will be described.

The target value setting section 30B of the present embodiment calculates a processing solution concentration target value a3 which changes with time.
And the pure water flow rate target value a2 are set. Target value setting unit 30
The configuration of B and the process of setting the target value are the same as those in the first embodiment, and a description thereof will be omitted.

In this embodiment, since the target concentration a3 of the processing liquid is set, the chemical concentration feedback control unit 40B uses the concentration target value calculation unit 41 provided in the chemical concentration feedback control unit 40A of the first embodiment. Not equipped. That is, the set processing solution concentration target value a3 is supplied to the subtractor 42 and the adder 45.
Each is given directly.

B5: Operation of the Second Embodiment The operation of the second embodiment is almost the same as the operation of the first embodiment (see item A5 described above). However, in the subtractor 42 of the chemical concentration feedback control unit 40B, the target value setting unit 30
The processing solution concentration deviation c3 is determined from the processing solution concentration target value a3 set in B and the processing solution concentration present value b3 given from the current concentration calculating unit 50. In addition, the adder 45 adds the concentration control operation amount of the processing liquid provided from the PII ² D calculation unit 43 to the processing liquid concentration target value a3 set by the target value setting unit 30B.

According to this embodiment, the same effect as that of the first embodiment can be obtained. In particular, the apparatus of the second embodiment is effective when it is desired to manage the target concentration a3 of the processing liquid and the target value a2 of the pure water flow rate.

B6: Variation Pattern of Target Value An example of a temporal variation pattern of the target concentration a3 of the processing liquid and the target value a2 of the pure water flow rate will be described below. Please refer to FIG. In this example, the target value setting unit 30 </ b> B starts the supply of the processing liquid to the substrate processing tank 1 filled with pure water until the processing liquid in the substrate processing tank 1 is completely replaced with the processing liquid. While the concentration target value a3 of the treatment liquid is set to be constant, the purifying water flow target value a2 is set smaller than the initial target value as the replacement with the treatment liquid proceeds. When the target concentration a3 of the processing liquid and the target value a2 of the pure water flow rate are set, the target value a1 of the chemical liquid flow rate is uniquely determined.
Here, since the concentration target value a3 is constant, the chemical liquid flow target value a1 becomes smaller as the replacement with the treatment liquid proceeds, similarly to the pure water flow target value a2. as a result,
The flow rate of the processing liquid supplied to the substrate processing tank 1 decreases as the replacement with the processing liquid proceeds. As the replacement with the processing liquid progresses, the average concentration of the processing liquid in the substrate processing tank 1 approaches the target value, but the rate of increase decreases. During this time, the processing liquid in the substrate processing tank 1 overflows with the supply of the processing liquid. According to this example, when the average concentration of the processing liquid in the substrate processing tank 1 becomes close to the target value, the amount of the processing liquid supplied to the substrate processing tank 1 decreases, so that the processing in the substrate processing tank 1 The amount of discharged liquid is also reduced, and the processing liquid required for replacement can be saved.

C: Third Embodiment C1: Configuration of Third Embodiment Apparatus In the substrate processing apparatus according to the present embodiment, the configurations of a pure water supply system and a chemical solution supply system to the substrate processing tank 1 are shown in FIG. Since it is the same as that of the first embodiment (see the above-mentioned items A1 to A3), the description is omitted here.

C4: Schematic Configuration of Control System FIG. 12 shows the configuration of the control system of this embodiment. This control system is functionally distinguished from a target value setting unit 30C, a chemical solution concentration feedback control unit 40C, a current concentration value calculation unit 50, a pure water pressure fluctuation feedback unit 60A, and a pure water flow rate feedback control unit 70. ing. Among them, the current concentration value calculation unit 50,
Each configuration of the pure water pressure fluctuation feedback section 60A and the pure water flow rate feedback control section 70 is the same as that of the first embodiment (the above item A4).
), And the description is omitted here.
Hereinafter, portions different from the first embodiment will be described.

The target value setting unit 30C of the present embodiment calculates a processing solution concentration target value a3 which changes with time.
And the chemical solution flow rate target value a1 are set. In the present embodiment, the chemical liquid concentration feedback control unit 40C calculates the pure water flow target value a2 based on the treatment liquid concentration target value a3 and the chemical liquid flow target value a1 by calculation. 48. The pure water flow target value calculation unit 48 calculates the pure water flow target value a2 by the following equation (6). a2 = a1 × (C ₀ −a3) / (1000 × a3) (6) where a1 is the chemical solution flow target value [cc / min] a2 is the pure water flow target value [liter / min] a3 is , Target concentration of treatment solution [%] C ₀ is the concentration of drug substance solution [%]

The pure water flow target value a2 calculated by the pure water flow target value calculator 48 is supplied to the concentration-flow converter 46 and the pure water flow feedback controller 70. Further, the target concentration a3 of the processing liquid set by the target value setting unit 30C is directly given to the subtractor 42 and the adder 45.

C5: Operation of the Third Embodiment The operation of the third embodiment is almost the same as the operation of the first embodiment (see item A5 described above). However, in the subtracter 42 of the chemical concentration feedback control unit 40C, the target value setting unit 30
The concentration deviation c3 of the processing solution is obtained from the target concentration value a3 of the processing solution set in C and the current concentration value b3 of the processing solution given from the current concentration value calculation unit 50. In addition, the adder 45 adds the concentration control operation amount of the processing liquid provided from the PII ² D calculation unit 43 to the processing liquid concentration target value a3 set by the target value setting unit 30C. Furthermore, the concentration-
The flow rate converter 46 converts the concentration control amount d3 of the processing liquid into the chemical liquid flow rate control amount d1 by using the pure water flow rate target value a2 calculated by the pure water flow rate target value calculator 48. Note that, instead of the pure water flow target value a2, the pure water flow current value b2
May be used. Further, the subtracter 71 of the pure water flow rate feedback control unit 70 calculates the pure water flow current value b2 detected by the pure water flow sensor 4 from the pure water flow target value a2 calculated by the pure water flow target value calculation unit 48. Is subtracted to calculate the pure water flow rate deviation c2.

According to this embodiment, the same effect as that of the first embodiment can be obtained. In particular, the apparatus of the third embodiment is effective when it is desired to manage the target concentration a3 of the processing liquid and the target value a1 of the chemical flow rate.

C6: Variation Pattern of Target Value An example of a temporal variation pattern of the target concentration a3 of the treatment liquid and the target value a1 of the chemical liquid flow will be described below. Please refer to FIG. In this example, the target value setting unit 30 </ b> C starts the supply of the processing liquid to the substrate processing tank 1 filled with pure water until the substrate processing tank 1 is completely replaced with the processing liquid. The initial target value of the processing solution concentration target value a3 is set to be larger than the subsequent processing solution concentration target value, while the chemical solution flow target value a1 is set to be constant. When the processing solution concentration target value a3 and the chemical solution flow target value a1 are set, the pure water flow target value a2 is uniquely determined. here,
Since the initial target value of the concentration target value a3 is set high and the chemical liquid flow target value a1 is constant, the initial target value of the pure water flow target value a2 becomes low. As a result, similarly to the change pattern in FIG. 8 of the first embodiment, the concentration of the processing liquid supplied to the substrate processing tank 1 in the initial stage of the replacement increases, and the average concentration of the processing liquid in the substrate processing tank 1 rises. Can be faster.
According to this example, when changing the concentration of the processing solution, it is not necessary to operate the chemical solution flow rate (as a result, the pure water flow rate is operated). Occurrence can be suppressed.

D: Fourth Embodiment D1: Configuration of Fourth Embodiment FIG. 14 shows a schematic configuration of a substrate processing apparatus according to this embodiment. In FIG. 14, the components indicated by the same reference numerals as those in FIG. 1 have the same configuration as that of the device of the first embodiment, and a description thereof will be omitted. Hereinafter, differences from the first embodiment will be described.

In the apparatus of the first embodiment shown in FIG. 1, the chemical solution pressure is controlled by the chemical solution pressure regulator 19 provided in the chemical solution supply passage 11, so that the chemical solution having a constant flow rate is supplied to the chemical solution introduction valve 9.
And introduced into the pure water supply path 2. On the other hand, the apparatus of the fourth embodiment replaces the chemical introduction valve 9, the chemical supply valve 10, and the chemical pressure regulator 19 of the first embodiment with
A chemical liquid flow control valve 21 is provided in the chemical liquid supply passage 11, and a pilot pressure is applied from the electropneumatic converter 20 to the chemical liquid flow control valve 21, whereby the opening of the valve of the chemical liquid flow control valve 21 is operated to supply the chemical liquid. It is configured to directly control the flow rate of the chemical solution in the passage 11.

The structure of the chemical liquid flow control valve 21 will be described with reference to FIG. The chemical liquid flow control valve 21 is connected to the introduction valve connection pipe 12 that is provided in the middle of the pure water supply path 2. The bottom surface of the chemical liquid flow control valve 21 and a bottomed hole drilled in the introduction valve connecting pipe 12 form a valve chamber 21a.
The valve chamber 21a is connected to the chemical solution supply path 11 through a connection hole 21b. Further, the valve chamber 21a is
g, it is connected to the pure water flow path 12a of the introduction valve connecting pipe 12 through communication. The valve chamber 21a is provided with a throttle valve 21c that opens and closes the chemical solution inlet 21g and adjusts the opening degree. The proximal end of the throttle valve 21c is connected and supported by a support 21e that slides and displaces in the valve body 21d. The support 9e is pressed downward by a spring 21h. In a state where air is not supplied to the pilot air supply port 21i, the support pair 21e and the throttle valve 21c are pressed downward by the spring force of the spring 21h, and at this time, the chemical liquid introduction port 21g is closed. The above configuration is common to the configuration of the chemical liquid introduction valve 9 described in the first embodiment.

The difference from the chemical introduction valve 9 is that when air (pilot pressure) is supplied to the pilot air supply port 21i, the throttle valve 21c rises integrally with the support 21e against the spring force of the spring 21h. That is, the throttle valve 21 stops at a position where the pilot pressure and the spring force are balanced, and the chemical solution inlet 21g is opened at an opening corresponding to the stop position. That is, by controlling the opening degree of the chemical liquid flow control valve 21 according to the pilot pressure given from the electropneumatic converter 20, the flow rate of the chemical liquid flowing through the chemical liquid supply path 11, that is, pure water The flow rate of the chemical solution introduced into the pure water in the supply path 2 is directly controlled.

D4: Schematic Configuration of Control System The configuration of the control system of the apparatus of this embodiment is substantially the same as that of the first embodiment shown in FIG. 3, and therefore, detailed description is omitted here. However, since it is necessary to convert the chemical flow rate operation amount d1 calculated by the concentration-flow rate conversion unit 46 into the chemical flow rate operation voltage Vd1 corresponding to the chemical flow rate control valve 21, the conversion formula used by the flow rate-voltage conversion unit 47 is used. (Equation (4) described in the first embodiment) needs to be changed. Specifically, the constant Ac in the equation (4) is changed to a constant determined from the specifications of the electropneumatic converter 20 and the chemical liquid flow rate control valve 21, and the constant Bc is changed to the pure water pressure reference value P ₀ and the chemical liquid flow rate. The value is changed to a constant determined from the specification of the control valve 21. These constants Ac and Bc can be obtained by experiments. For the same reason, the pressure-voltage converter 6
The conversion formula used in Step 2 (the pressure fluctuation value Δe2 of pure water is calculated as the correction voltage Δ
The primary equation for conversion to Ve2) is also experimentally determined in consideration of the specifications of the electropneumatic converter 20 and the chemical liquid flow control valve 21, and the like.

D5: Operation of the embodiment apparatus The operation of the embodiment apparatus is the same as that of the first embodiment except for the process of controlling the flow rate of the chemical solution by the chemical flow rate control valve 21. The description will be omitted, and the following description will focus on the control process of the chemical solution flow rate by the chemical solution flow control valve 21.

The chemical concentration feedback control unit 40A calculates a chemical flow rate operation amount that cancels the concentration deviation of the processing liquid, and converts this to the chemical flow rate operation voltage Vd1 corresponding to the chemical flow rate control valve 21.
And supplied to the pure water pressure fluctuation feedback section 60A. on the other hand,
The pure water pressure fluctuation feedback unit 60A is configured such that when the pure water pressure in the pure water supply path 2 increases, the flow rate of the chemical solution introduced into the pure water decreases.
Is corrected. Conversely, when the pressure of the pure water in the pure water supply path 2 decreases, the flow rate of the chemical solution introduced into the pure water increases. Therefore, the pure water pressure fluctuation feedback unit 60A causes the chemical flow rate operation voltage Vd1 to decrease the chemical solution flow rate. Is corrected. The corrected chemical liquid flow rate operation voltage Vd1 ′ is converted into a pilot pressure by the electropneumatic converter 20 and provided to the chemical liquid flow rate control valve 21. as a result,
When the pure water pressure in the pure water supply path 2 becomes higher than the pure water pressure reference value P ₀ , the opening of the chemical liquid flow control valve 21 increases in accordance with the pressure fluctuation, and conversely, the pure water pressure increases. When the pressure becomes lower than the pure water reference value P ₀ , the opening degree of the chemical liquid flow control valve 21 decreases according to the pressure fluctuation. As described above, since the opening degree of the chemical liquid flow control valve 21 is operated according to the fluctuation of the pure water pressure in the pure water supply path 2, a constant amount of the chemical liquid is always supplied irrespective of the fluctuation of the pure water pressure. Introduced inside.

D7: Modifications (1) The chemical liquid flow control valve 21 described in the present embodiment is replaced by the chemical liquid introduction valve 9, the chemical liquid supply valve 10, and the chemical liquid of each device of the above-described second and third embodiments. It is also possible to use in place of the pressure regulator 19. In this case, FIGS.
The conversion formulas of the flow-voltage conversion unit 47 and the pressure-voltage conversion unit 62 shown therein may be changed in the same manner as described in the fourth embodiment.

(2) In the first to third embodiments, as shown in FIG. 2, the chemical solution introduction valve 9 is connected to the introduction valve connecting pipe 12 interposed in the pure water supply path 2, and In the embodiment, as shown in FIG. 15, the chemical solution flow control valve 21 is connected to the introduction valve connecting pipe 12 similarly. However, the chemical liquid introduction valve 9 and the chemical liquid flow control valve 21 do not necessarily need to be directly connected to the pure water supply path 2, and can be provided at an appropriate position in the chemical liquid supply path 11.

[0121]

As apparent from the above description, the present invention has the following effects. According to the first and second aspects of the present invention, at least one of the two target values set from the target value of the chemical flow rate, the target value of the pure water flow rate, and the target concentration of the processing liquid. Is changed over time, so that the processing solution in the substrate processing section can be efficiently replaced, the processing solution required for replacement can be saved,
Alternatively, the degree of freedom in controlling the substrate processing apparatus can be increased, for example, by suppressing unevenness in the concentration of the processing liquid in the substrate processing unit.

According to the third aspect of the present invention, the target value of the chemical flow rate and the target value of the pure water flow rate are set as the target values, and at least one of the target values is changed with the passage of time. The degree of freedom in controlling the device can be increased.

According to the fourth aspect of the invention, in the initial stage of replacing the processing liquid in the substrate processing unit, the target value of the chemical liquid flow rate and the target value of the pure water flow rate are both set large, and the replacement of the processing liquid has progressed to some extent. Since each flow rate target value is reduced at the stage, the flow rate of the processing liquid supplied to the substrate processing unit in the initial stage of the processing liquid replacement is increased, and the processing liquid of the substrate processing unit is efficiently replaced. Can be.

According to the fifth aspect of the present invention, in the initial stage of replacing the processing liquid in the substrate processing section, the ratio of the chemical liquid flow rate to the pure water flow rate is increased, and the processing liquid having a high concentration is subjected to the substrate processing. Since the rise in the average concentration of the processing liquid in the substrate processing unit is accelerated by supplying the processing liquid in the processing unit, the processing liquid in the substrate processing unit can be efficiently replaced.

According to the sixth aspect of the present invention, in the initial stage of replacing the processing liquid in the substrate processing section, the ratio of the pure water flow rate to the chemical liquid flow rate is increased, and the processing liquid having a low concentration is subjected to the substrate processing. Since it is supplied to the processing unit, it is possible to suppress the occurrence of unevenness in the concentration of the processing liquid in the substrate processing unit.

According to the seventh aspect of the present invention, the target value of the treatment liquid and the target value of the pure water flow rate are set as the target values.
Since at least one of the target values is changed over time, the degree of freedom in controlling the substrate processing apparatus can be increased.

According to the eighth aspect of the present invention, while the target concentration of the processing liquid is kept constant over time, the target value of the pure water flow rate is reduced as the replacement of the processing liquid in the substrate processing unit progresses. Therefore, the flow rate of the chemical liquid is inevitably reduced, and the flow rate of the processing liquid supplied to the substrate processing unit is also reduced. As a result, it is possible to save the processing liquid required for replacing the processing liquid in the substrate processing unit.

According to the ninth aspect of the present invention, the target value of the treatment liquid and the target value of the chemical flow rate are set as the target values.
Since at least one of the target values is changed over time, the degree of freedom in controlling the substrate processing apparatus can be increased.

According to the tenth aspect of the present invention, the target value of the chemical liquid flow rate is set to be constant over time, while the target concentration of the processing liquid is set high in the initial stage of replacing the processing liquid in the substrate processing section. Therefore, similarly to the invention of the fifth aspect, a processing solution having a high concentration is supplied into the substrate processing unit in the initial stage of the replacement. As a result, the rise of the average concentration of the processing liquid in the substrate processing unit becomes faster, and the replacement of the processing liquid in the substrate processing unit can be performed efficiently.

According to the eleventh aspect of the present invention, it is possible to easily set a target value that changes with time.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic configuration of a substrate processing apparatus according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a structure of a chemical liquid introduction valve.

FIG. 3 is a block diagram functionally showing a control system of the first embodiment.

FIG. 4 is an explanatory diagram of a change pattern of a target value.

FIG. 5 is a flowchart showing a pre-process of a target value setting process.

FIG. 6 is a flowchart showing a process of outputting a target value.

FIG. 7 is a diagram illustrating an example of a change pattern of a target value according to the first embodiment.

FIG. 8 is a diagram showing another example of the change pattern of the target value of the first embodiment.

FIG. 9 is a diagram showing still another example of the change pattern of the target value of the first embodiment.

FIG. 10 is a block diagram functionally showing a control system according to a second embodiment.

FIG. 11 is a diagram illustrating an example of a change pattern of a target value according to the second embodiment.

FIG. 12 is a block diagram functionally showing a control system of a third embodiment.

FIG. 13 is a diagram illustrating an example of a change pattern of a target value according to the third embodiment.

FIG. 14 is a diagram illustrating a schematic configuration of a substrate processing apparatus according to a fourth embodiment.

FIG. 15 is a cross-sectional view showing a structure of a chemical liquid flow control valve.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Substrate processing tank 2 ... Pure water supply path 3 ... Pure water pressure regulator 4 ... Pure water flow sensor 5 ... Chemical liquid mixing part 6 ... Electro-pneumatic converter 7 ... Pure water pressure sensor 8 ... Pure water supply valve 9 ... Chemical liquid Introducing valve 10 ... Chemical liquid supply valve 11 ... Chemical liquid supply path 13 ... Chemical liquid tank 14 ... Gas supply path 15 ... Gas pressure regulator 16 ... Electro-pneumatic converter 18 ... Chemical liquid flow rate sensor 19 ... Chemical liquid pressure regulator 20 ... Electro-pneumatic converter 21 ... Chemical solution flow control valve 30A-30C ... Target value setting unit 31 ... Variable designation unit 32 ... Target value output unit 40A-40C ... Chemical solution concentration feedback control unit 41 ... Concentration target value calculation unit 42 ... Subtractor 43 ... PII ² D Operation unit 44 Switch 45 Adder 46 Concentration-flow rate conversion unit 47 Flow rate-voltage conversion unit 50 Current concentration value calculation unit 60A Pure water pressure fluctuation feedback unit 61 Subtractor 62 Pressure-voltage conversion unit 63 … Adder 70… Pure water flow Feedback controller 71 Subtractor 72 PID calculator 73 Switch 74 Adder 75 Flow-voltage converter a1 Chemical liquid flow target value b1 Chemical liquid flow current value a2 Pure water flow target value b2 Pure water flow Current value a3: Target concentration of treatment liquid b3: Present concentration of treatment liquid c1: Chemical liquid flow deviation d1: Chemical liquid flow operation amount c2: Pure water flow deviation d2 ... Pure water flow operation amount c3: Concentration deviation of processing liquid d3 ... concentration operation amount of the processing liquid Vd1 ... chemical flow operating voltage Vd1 '... corrected chemical flow operating voltage Vd2 ... pure water flow rate operating voltage e2 ... pure water pressure current value P ₀ ... pure water pressure reference value

Claims (11)

[Claims] 1. A substrate processing apparatus for performing a surface treatment of a substrate with a processing liquid obtained by mixing pure water and a chemical solution, wherein the substrate processing unit performs a surface processing of the substrate with a processing liquid; A pure water supply path connected between the section and the pure water supply source; a chemical liquid tank having a closed structure for storing a chemical liquid; a chemical liquid supply path having one end introduced into the chemical liquid in the chemical liquid tank; A chemical pressure feeding means for feeding a chemical solution in a tank to the chemical solution supply path, an inlet side connected to the other end of the chemical solution supply path, an outlet side connected to the pure water supply path, a chemical pressure on the inlet side, and pure water on the outlet side. A chemical solution introducing valve for introducing a chemical solution having a flow rate corresponding to a pressure difference from the pressure into the pure water supply path, and a chemical solution pressure regulator for adjusting a chemical solution pressure in the chemical solution supply channel based on a chemical solution flow rate operation amount. A pure water supply upstream of a position where a chemical solution is introduced into the pure water supply passage; A pure water pressure regulator that is disposed on the path and adjusts the pure water pressure in the pure water supply path based on the pure water flow operation amount; a chemical solution flow target value, a pure water flow target value, and a treatment liquid. Target value setting means for setting two target values of the concentration target values and changing at least one target value of the two set target values with the passage of time; and setting the target value setting means. Based on the set target value, the chemical liquid flow rate operation amount is adjusted, and the chemical liquid flow rate operation amount adjusting means is provided to the chemical liquid pressure regulator.The pure water flow rate operation is performed based on the target value set by the target value setting means. A substrate processing apparatus comprising: a pure water flow rate operation amount adjusting means for adjusting an amount of the pure water flow to be applied to the pure water pressure regulator. 2. A substrate processing apparatus for performing a surface treatment of a substrate with a processing liquid obtained by mixing pure water and a chemical solution, wherein the substrate processing unit performs a surface processing of the substrate with the processing liquid; A pure water supply path connected between the section and the pure water supply source; a chemical solution tank having a sealed structure for storing a chemical solution; one end being introduced into the chemical solution in the chemical solution tank, and the other end being the pure water supply A liquid supply path connected in the middle of the path; a liquid supply means for feeding the liquid in the liquid tank to the liquid supply path; and operating the valve opening based on a liquid flow rate operation amount to supply the liquid. A chemical liquid flow rate control valve for adjusting a chemical liquid flow rate in the path, a chemical liquid is disposed in the pure water supply path upstream of a position where the chemical liquid is introduced into the pure water supply path, and based on a pure water flow operation amount, A pure water pressure regulator for adjusting the pure water pressure in the pure water supply path; Two target values among a target value, a pure water flow target value, and a treatment liquid concentration target value are set, and at least one of the two set target values is changed over time. A target value setting unit, based on the target value set by the target value setting unit, a chemical liquid flow operation amount adjustment unit that adjusts a chemical liquid flow operation amount and gives the chemical liquid flow operation valve to the chemical liquid flow control valve; A substrate processing apparatus comprising: a pure water flow operation amount adjusting unit that adjusts a pure water flow operation amount based on a set target value and gives the pure water flow operation amount to the pure water pressure regulator. 3. The substrate processing apparatus according to claim 1, wherein the target value setting unit sets a chemical solution flow target value and a pure water flow target value. 4. The apparatus according to claim 3, wherein the target value setting unit starts supplying the processing liquid into the substrate processing unit filled with pure water and starts processing liquid in the substrate processing unit. Until it is replaced with
A substrate processing apparatus for setting respective initial target values of a chemical solution flow target value and a pure water flow target value higher than the respective subsequent target values. 5. The apparatus according to claim 3, wherein the target value setting unit starts supplying the processing liquid into the substrate processing unit filled with pure water, and sets the processing liquid in the substrate processing unit. Until it is replaced with
A substrate processing apparatus that sets an initial target value of a chemical solution flow target value higher than a subsequent chemical solution flow target value, while setting the pure water flow target value constant. 6. The apparatus according to claim 3, wherein the target value setting unit starts supplying the processing liquid into the substrate processing unit that is filled with pure water, and sets the processing liquid in the substrate processing unit to a target value. Until it is replaced with
A substrate processing apparatus that sets an initial target value of a pure water flow target value higher than a subsequent pure water flow target value while setting a chemical liquid flow target value to be constant. 7. The substrate processing apparatus according to claim 1, wherein the target value setting unit sets a target concentration of the processing liquid and a target value of the pure water flow rate. 8. The apparatus according to claim 7, wherein the target value setting unit starts supplying the processing liquid into the substrate processing unit that is filled with pure water and starts processing liquid supply into the substrate processing unit. Until it is replaced with
A substrate processing apparatus that sets a target concentration of a processing solution to a constant value, while decreasing the pure water flow target value from its initial target value as the replacement with the processing solution proceeds. 9. The substrate processing apparatus according to claim 1, wherein the target value setting unit sets a target concentration of the processing liquid and a target value of the chemical flow rate. 10. The apparatus according to claim 9, wherein the target value setting unit starts processing liquid supply into the substrate processing unit filled with pure water and starts processing liquid supply within the substrate processing unit. Until it is replaced with
A substrate processing apparatus for setting an initial target value of a processing solution concentration target value larger than a subsequent processing solution concentration target value, while setting a chemical solution flow rate target value constant. 11. The apparatus according to claim 1, wherein the target value setting means is configured to specify a type of a target value to be set and determine a change pattern of the specified target value. And a target value output unit that generates and outputs a target value that changes over time based on the specified variable.