JPH10340877A - Substrate processing system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a substrate processing system, wherein a concentration fluctuation of a process liquid caused by a fluctuation in pure water flow rate is suppressed. SOLUTION: A chemical liquid introduction valve 9 introduces a flow rate of chemical liquid, which corresponds to the pressure difference between a chemical liquid pressure on an inlet side and a pure water pressure on an outlet side, into a pure water in a pure water supply channel 2. A pure water flow rate feedback control part 70 obtains a deviation between a pure water flow rate target value a2 set at a target value setting part 30 and a pure water flow rate current value b2 of the pure water supply channel 2 for calculating the pure water flow rate control operation amount so as to cancel the pure water flow rate deviation. Then the pure water flow rate control operation amount is added to the pure water flow rate target value a2 to obtain a pure water flow rate operation amount, and then the pure water flow rate operation amount is converted into a pure water flow rate operation voltage Vd2 for outputting. A pure water pressure-adjuster 3 adjusts, based on the pure water flow amount operation voltage Vd2, the pure water pressure of the pure water supply channel 2 so that the pure water flow rate amount is kept constant.

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]

However, the prior art having such a structure has the following problems. As described above, the pure water supply path is provided with the pure water pressure regulator. This pure water pressure regulator works to keep the secondary pressure constant even if the pressure of the primary pure water supply source fluctuates. When the secondary pressure of the pure water pressure regulator is kept constant, the pure water flow rate becomes constant unless the flow path resistance of the pure water supply path connected to the secondary side of the pure water pressure regulator changes. . However, the flow path resistance of the pure water supply path is not always constant. For example, when processing a substrate with a processing liquid at room temperature, pure water at room temperature flows through the pure water supply path, and when processing with a heated processing liquid, heated pure water flows. There is a difference in the thermal deformation of the pure water supply path between the case where pure water at normal temperature flows and the case where heated pure water flows. In other words, the flow resistance of the pure water supply path varies depending on the temperature of the pure water flowing through. As a result, even if the pure water pressure in the pure water supply path is kept constant, the flow resistance of the pure water supply path changes, so that the flow rate of the pure water fluctuates. Fluctuations in the flow rate of pure water cause fluctuations in the concentration of the processing solution.

[0007] The present invention has been made in view of such circumstances, and a substrate processing apparatus capable of suppressing fluctuations in the concentration of a processing liquid due to fluctuations in the flow rate of pure water flowing through a pure water supply path. The main purpose is to provide

[0008]

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 is connected to the pure water supply path, and a chemical liquid introduction valve for introducing a chemical liquid into the pure water supply path at a flow rate corresponding to a differential pressure between the chemical liquid pressure on the inlet side and the pure water pressure on the outlet side, A chemical pressure regulator for adjusting a chemical pressure in the chemical supply path based on a predetermined chemical flow rate operation amount set in advance in relation to a liquid concentration target value; and pure water flowing through the pure water supply path. Target value setting means for setting a pure water flow target value, and 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, 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; and a pure water flow deviation for obtaining a deviation between a pure water flow target value provided from the target value setting means and a pure water flow present value. Calculating means;
A pure water flow control amount including a pure water flow operation amount calculating means for calculating the pure water flow operation amount to cancel the pure water flow deviation, and a pure water flow operation amount calculation means for giving the pure water flow operation amount to the pure water pressure regulator; , Is provided.

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 liquid obtained by mixing pure water and a chemical solution, wherein the substrate is subjected to a surface processing of the substrate with the processing liquid. 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 set in advance in relation to a chemical supply path connected in the middle of the pure water supply path, a chemical liquid pumping means for sending the chemical in the chemical tank to the chemical supply path, and a concentration target value of the processing liquid. A chemical liquid flow rate control valve for adjusting the flow rate of the chemical liquid in the chemical liquid supply path by operating the valve opening based on a predetermined chemical liquid flow rate operation amount, and pure water pure water flowing through the pure water supply path. Target value setting means for setting a flow rate target value, and a chemical solution is supplied to the pure water supply path. Disposed in the pure water supply path on the upstream side of a position to be input, based on the pure water flow rate operation amount of pure water pressure regulator for adjusting the pure water pressure of the pure water supply path,
A pure water flow rate target value given from the target value setting means,
A pure water flow deviation calculating means for calculating a deviation from the pure water flow current value, and a pure water flow manipulated variable that cancels the pure water flow deviation, and the pure water flow manipulated variable is supplied to the pure water pressure regulator. And a pure water flow rate feedback control means including a pure water flow operation amount calculation means to be provided.

According to a third aspect of the present invention, in the apparatus according to the first aspect, the apparatus further obtains a pure water pressure current value in the pure water supply path, and the pure water pressure current value is determined in advance. When the pressure becomes higher than the pure water pressure reference value, the chemical liquid flow rate operation amount is corrected in the direction of increasing the chemical liquid pressure, and the corrected amount is supplied to the chemical liquid pressure regulator, and the pure water pressure current value is changed to the pure water pressure reference value. When the pressure becomes lower than the above, the pure water pressure fluctuation feedback means is provided for correcting the chemical liquid flow rate operation amount in the direction of lowering the chemical liquid pressure and giving it to the chemical liquid pressure regulator. Pure water pressure detecting means for actually measuring the current pure water pressure value in the water supply path, and comparing the actually measured pure water pressure current value with a predetermined pure water pressure reference value to obtain a pure water pressure value. A pure water pressure fluctuation value calculation means for obtaining a current value pressure fluctuation value; In which the pure water pressure fluctuation value by adding the drug solution flow rate operation amount and a pure water pressure fluctuation value adding means for providing the liquid chemical pressure regulator.

According to a fourth aspect of the present invention, in the apparatus according to the second aspect, the apparatus further obtains a pure water pressure current value in the pure water supply path, and the pure water pressure current value is determined in advance. When the pressure becomes higher than the pure water pressure reference value, the chemical liquid flow rate operation amount is corrected in a direction to increase the chemical liquid flow rate and given to the chemical liquid flow rate control valve, and the pure water pressure current value becomes the pure water pressure reference value. When the water flow rate becomes lower than the pure water pressure fluctuation feedback means, the pure water pressure fluctuation feedback means is provided to correct the chemical liquid flow rate operation amount in the direction of decreasing the chemical liquid flow rate and to provide the chemical liquid flow rate control valve with the pure water pressure fluctuation feedback means. Pure water pressure detecting means for actually measuring the current pure water pressure value in the water supply path, and comparing the actually measured pure water pressure current value with a predetermined pure water pressure reference value to obtain a pure water pressure value. Pure water pressure fluctuation value calculating means for obtaining a pressure fluctuation value of a current value; In which the pure water pressure fluctuation value is added to the chemical flow operation amount and a pure water pressure fluctuation value adding means for providing the liquid chemical flow rate control valve.

According to a fifth aspect of the present invention, in the apparatus according to the first aspect, the apparatus further obtains a current pure water pressure value in the pure water supply path, and the pure water pressure current value is determined in advance. When the pressure becomes higher than the pure water pressure reference value, the chemical liquid flow rate operation amount is corrected in the direction of increasing the chemical liquid pressure, and the corrected amount is supplied to the chemical liquid pressure regulator, and the pure water pressure current value is changed to the pure water pressure reference value. When the pressure becomes lower than the above, the pure water pressure fluctuation feedback means is provided for correcting the chemical liquid flow rate operation amount in the direction of lowering the chemical liquid pressure and giving it to the chemical liquid pressure regulator. A pure water pressure calculating means for calculating a pure water pressure current value based on a pure water flow current value in the water supply path by calculation, the calculated pure water pressure current value, and a predetermined pure water pressure reference value; By comparing the pressure fluctuation value of the current pure water pressure value And Mel pure water pressure fluctuation value calculating means, in which the pure water pressure variation value by adding the drug solution flow rate operation amount and a pure water pressure fluctuation value adding means for providing the liquid chemical pressure regulator.

According to a sixth aspect of the present invention, in the apparatus according to the second aspect, the apparatus further obtains a pure water pressure current value in the pure water supply path, and the pure water pressure current value is determined in advance. When the pressure becomes higher than the pure water pressure reference value, the chemical liquid flow rate operation amount is corrected in a direction to increase the chemical liquid flow rate and given to the chemical liquid flow rate control valve, and the pure water pressure current value becomes the pure water pressure reference value. When the water flow rate becomes lower than the pure water pressure fluctuation feedback means, the pure water pressure fluctuation feedback means is provided to correct the chemical liquid flow rate operation amount in the direction of decreasing the chemical liquid flow rate and to provide the chemical liquid flow rate control valve with the pure water pressure fluctuation feedback means. A pure water pressure calculating means for calculating a pure water pressure current value based on a pure water flow current value in the water supply path by calculation, the calculated pure water pressure current value, and a predetermined pure water pressure reference value; Is compared with the pressure fluctuation value of the current pure water pressure value. Pure water pressure fluctuation value calculating means for determining,
A pure water pressure fluctuation value adding means for adding the pure water pressure fluctuation value to the chemical liquid flow rate operation amount and giving it to the chemical liquid flow rate control valve.

According to a seventh aspect of the present invention, in the apparatus according to any one of the first to sixth aspects, the target value setting means sets a pure water flow rate target value that changes with time. .

According to an eighth aspect of the present invention, in the apparatus according to the seventh aspect, the target value setting unit 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 pure water flow target value is set higher than the subsequent target value.

According to a ninth aspect of the present invention, in the apparatus according to the first or second aspect, the apparatus further calculates a pure water flow rate current value based on the chemical solution flow rate current value and the treatment solution concentration current value. A pure water flow rate calculating means for determining the current value of the pure water flow rate to the pure water flow rate deviation calculating means.

[0017]

The operation of the first aspect of the invention is as follows. The chemical pressure feeding means sends the chemical in the chemical tank to the chemical supply path. The chemical pressure regulator adjusts the pressure of the chemical in the chemical supply path to a constant value based on a predetermined chemical flow rate operation amount.
The pressure-adjusted drug solution is supplied to the inlet side of the drug solution introduction valve via the drug solution supply path. On the other hand, the pure water pressure regulator adjusts the pressure of pure water in the pure water supply path based on the pure water flow operation amount. The pressure-adjusted pure water is supplied to the outlet side of the chemical liquid introduction valve via the pure water supply path. As a result, a chemical solution having a flow rate corresponding to the pressure difference between the chemical solution pressure on the inlet side and the pure water pressure on the outlet side of the chemical solution introduction valve is introduced into the pure water. At this time, when the flow path resistance in the pure water supply path changes and the pure water flow rate fluctuates, the pure water flow rate feedback control means suppresses the fluctuation of the pure water flow rate as follows. That is, the pure water flow deviation calculating means obtains a deviation between the pure water flow target value provided from the target value setting means and the pure water flow present value. Subsequently, the pure water flow manipulated variable calculating means calculates a pure water flow manipulated variable that cancels out the pure water flow deviation, and gives the pure water flow manipulated variable to the pure water pressure regulator. This adjusts the pure water pressure in the pure water supply path,
Maintain a constant flow of pure water.

According to the second aspect of the present invention, the chemical liquid flow control valve operates the opening degree of the valve based on the predetermined chemical liquid flow rate operation amount, so that the chemical liquid flows at a predetermined flow rate in the chemical liquid supply passage. Then, it is introduced into pure water in the pure water supply channel. At this time, when the flow path resistance in the pure water supply path changes and the pure water flow rate fluctuates, the pure water flow rate feedback control means suppresses the fluctuation of the pure water flow rate. The operation of the pure water flow rate feedback control means is the same as in the case of the first aspect of the present invention, and a description thereof will be omitted.

The operation of the invention described in claim 3 is as follows. According to the first aspect of the present invention, the flow rate of pure water in the pure water supply path is detected, and the flow rate of pure water is controlled based on the fluctuation in pure water flow. did. By the way, when heated pure water flows through the pure water supply path, not only does the flow path resistance of the pure water supply path change,
The pure water pressure regulator itself may be thermally deformed, and the pure water pressure in the secondary-side pure water supply path may fluctuate. as a result,
Despite maintaining a constant chemical pressure on the inlet side of the chemical introduction valve, the differential pressure between the chemical pressure on the inlet side and the pure water pressure on the outlet side fluctuates. Due to the fluctuation of the differential pressure, the flow rate of the chemical solution introduced into the pure water fluctuates, causing a problem that the concentration of the processing liquid fluctuates.

The invention according to claim 3 is provided with pure water pressure fluctuation feedback means in order to solve such a problem. That is, the pure water pressure detecting means actually measures the present value of the pure water pressure in the pure water supply path. Then, the pure water pressure fluctuation calculating means obtains the pressure fluctuation value of the pure water pressure current value by comparing the actually measured pure water pressure current value with a predetermined pure water pressure reference value. Pure water pressure fluctuation value adding means changes the chemical liquid pressure in accordance with the fluctuation of the pure water pressure by adding the pure water pressure fluctuation value to the chemical liquid flow rate operation amount.
In other words, when the pure water pressure increases, the chemical liquid pressure increases accordingly, and conversely, when the pure water pressure decreases, the chemical liquid pressure decreases accordingly. Is always constant, and a constant amount of the chemical is always introduced into the pure water in the pure water supply path.

The operation of the invention described in claim 4 is as follows. According to the third aspect of the invention, the chemical solution pressure is controlled in accordance with the fluctuation of the pure water pressure in the pure water supply channel. However, in the fourth aspect of the invention, the chemical solution flow rate in the chemical solution supply channel is directly controlled. That is, when the pressure of the pure water in the pure water supply path increases, the flow rate of the chemical solution introduced into the pure water decreases. Therefore, the pure water pressure fluctuation feedback unit corrects the manipulated flow rate of the chemical solution in the direction of increasing the flow rate of the chemical solution.
The corrected chemical liquid flow operation amount is given to the chemical liquid flow control valve. As a result, the opening of the chemical liquid flow control valve increases, and the chemical liquid flow rate increases. Conversely, when the pressure of the pure water in the pure water supply path decreases, the flow rate of the chemical solution introduced into the pure water increases. Therefore, the pure water pressure fluctuation feedback unit corrects the chemical flow rate operation amount in a direction to decrease the chemical flow rate. . As a result, the opening degree of the chemical liquid flow rate control valve decreases, and the chemical liquid flow rate decreases. As described above, the chemical liquid flow rate is directly controlled so as to suppress the fluctuation of the chemical liquid flow rate caused by the fluctuation of the pure water pressure in the pure water supply path. A certain amount of chemical solution is always introduced.

According to the fifth and sixth aspects of the present invention, the pure water pressure calculating means calculates the pure water pressure current value based on the pure water flow present value in the pure water supply path by calculation.
Hereinafter, similarly to the third and fourth aspects of the present invention, the pure water pressure fluctuation value calculating means obtains the pressure fluctuation value of the current pure water pressure value, and the pure water pressure fluctuation value adding means corrects the chemical liquid flow rate operation amount. .

According to the seventh aspect of the present invention, the target value setting means sets the target value of the pure water flow rate which changes with the passage of time, thereby suppressing the unevenness of the concentration of the processing liquid in the substrate processing section. For example, the degree of freedom in controlling the substrate processing apparatus can be increased.

The operation of the invention described in claim 8 is as follows. If a certain amount of chemical liquid flow operation is set in advance, a certain amount of chemical liquid flows through the chemical liquid supply path. At this time, if the pure water flow rate target value of the pure water is set to a constant value, the following problem occurs. 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, when the processing solution obtained by setting the chemical solution flow rate and the pure water flow rate to respective fixed amounts is supplied to the substrate processing unit, if the processing solution has a high concentration, the pure water in the substrate processing unit has a high concentration. Due to the introduction of the processing liquid, large unevenness occurs in the concentration of the processing liquid in the substrate processing unit. Such unevenness in the concentration of the processing liquid is not preferable for substrate processing.

In order to solve the above problems, the invention according to claim 8 is to increase the pure water flow target value in the initial stage of supplying the processing liquid into the substrate processing section filled with pure water. By setting, the processing liquid having a relatively low concentration is supplied to the substrate processing unit so that the unevenness of the concentration of the processing liquid in the substrate processing unit is reduced. When the average concentration of the processing solution in the substrate processing unit has increased to some extent as the replacement of the substrate processing unit has progressed, the target value of the pure water flow rate is returned to an appropriate value so that the processing solution having the desired concentration can be processed in the substrate processing unit. Supply to the department.

According to the ninth aspect of the present invention, the pure water flow rate calculating means calculates the pure water flow rate current value based on the chemical solution flow rate current value and the treatment solution concentration current value, and calculates the pure water flow rate value. The present value is given to the pure water flow rate deviation calculating means. The other operations are the same as those of the first and second aspects of the present invention, and the description thereof will not be repeated.

[0027]

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 overflow and discharge the excess processing liquid. 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. Further, the present invention is not applied to a substrate processing tank, but can be applied to a substrate processing apparatus having a processing unit for processing substrates one by one.

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 therein. 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.

The chemical mixing section 5 has a pure water supply valve 8 for opening and closing the pure water supply path 2 and a plurality of chemical liquid introduction valves for individually introducing different kinds of chemicals into the pure water of the pure water supply path 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) The number of chemical liquid supply systems is provided in accordance with the type of processing liquid used in this 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 17 for removing particles in the chemical is provided in the chemical supply path 11 in order from the chemical tank 13 side.
And a chemical solution pressure regulator 19 for adjusting the chemical solution pressure on the secondary side. The secondary side of this chemical liquid pressure regulator 19 is connected to the above-mentioned chemical liquid introduction valve 9. Chemical pressure regulator 1
Reference numeral 9 denotes a control valve having a configuration similar to that of the above-described pure water pressure regulator 3, which regulates the secondary side chemical liquid pressure according to the pilot pressure given from the electropneumatic converter 20. 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,
It comprises a pure water pressure fluctuation feedback section 60A and a pure water flow rate feedback control section 70. 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 30 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. 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 30 sets a pure water flow rate target value a2 that changes with time. On the other hand, in the present embodiment, since the chemical liquid flow rate target value is constant with time, a constant chemical liquid flow rate operation voltage Vd1 is supplied to the electropneumatic converter 20 via the pure water pressure fluctuation feedback unit 60A. ing. Of course, the target value of the chemical liquid flow rate that is constant over time may be set from the target value setting unit 30. Since the concentration of the processing solution used for substrate processing is a constant value, in that sense, like the chemical solution flow rate target value,
It is also conceivable to make the pure water flow target value constant over time. However, as will be described later in detail, in order to minimize unevenness in the concentration of the processing liquid in the substrate processing tank 1, it is preferable to change the pure water flow rate target value over time.

As shown in FIG. 3, the target value setting unit 30
It comprises a variable designation section 31 and a target value output section 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 over time, based on a variable specified through the variable specifying unit 31,
Here, the pure water flow rate target value is output.

The pure water pressure fluctuation feedback section 60A determines in advance the pure water pressure (current pure water pressure value) e2 in the pure water supply path 2 calculated by the pure water pressure current value calculating section 64 described later. obtained when it becomes higher than the pure water pressure reference value P ₀ corrects the chemical flow rate operation voltage Vd1 in a direction to increase the chemical pressure,
Conversely, pure water pressure current value e2 is when I becomes lower than that of pure water pressure reference value P _0, to correct the chemical flow rate operation voltage Vd1 in a direction to lower the chemical pressure. The thus-corrected chemical flow rate operation voltage Vd1 ′ is supplied to the electropneumatic converter 20. The pure water pressure current value calculation unit 64 calculates the pure water pressure current value e2 from the pure water flow current value b2 detected by the pure water flow sensor 4.
Is calculated. Therefore, according to the pure water pressure fluctuation feedback unit 60A, it is not necessary to provide the pure water pressure sensor 7 for detecting the pure water pressure in the pure water supply path 2.

The pure water pressure current value calculating section 64 calculates a pure water pressure current value e2 according to the following equation (1). e2 = b2 × Ec + Fc (1) where b2 is the current pure water flow rate [liter / min] e2 is the current pure water pressure value [Kgf / min] Ec and Fc are the flow paths of the pure water supply path 2 Constants Determined by Resistance Constants Ec and Fc are determined by experiments.

The pure water flow rate feedback control unit 70 obtains a deviation c2 between the pure water flow rate target value a2 set by the target value setting unit 30 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 the Example Apparatus (1) Setting of Target Value First, the operator operates the variable specifying section 31 to determine the type of target value (in this embodiment, the pure water flow rate target value a2).
And a variable for determining the change pattern of the target value. Based on these specifications,
The target value output unit 32 outputs a pure water flow rate target value a2 that changes with time.

The above-mentioned target value is set 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. The same applies to the case where a substrate is processed using a certain processing liquid and then the substrate is processed using 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,
The pure water in the substrate processing tank 1 is replaced with a new processing 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 time is
The description will be made on the assumption that the supply of the processing liquid to the substrate processing tank 1 is started.

(2) Operation of the Pure Water Pressure Fluctuation Feedback Unit 60A The subtracter 61 of the pure water pressure fluctuation feedback unit 60A calculates the pure water pressure current value e2 calculated by the pure water pressure current value calculation unit 64 from
The pressure fluctuation value Δe2 of the current pure water pressure value e2 is obtained by subtracting a predetermined pure water pressure reference value P ₀ .
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. Predetermined fixed chemical flow rate operation voltage Vd
1 and the correction voltage ΔVe2 are added by the adder 63 to obtain the corrected chemical liquid flow rate operation voltage Vd1 ′. This chemical liquid flow rate operation voltage Vd1 'is
Given to. The electropneumatic converter 20 has a chemical liquid flow rate operation voltage Vd.
The pilot pressure corresponding to 1 'is given to the chemical liquid 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.

(3) Operation of the Pure Water Flow Rate Feedback Control Unit 70 The subtracter 71 of the pure water flow rate feedback control unit 70 uses the pure water flow rate sensor 4 from the pure water flow rate target value a2 set by the target value setting unit 30. By subtracting the detected pure water flow rate current value b2, a pure water flow rate deviation c2 is calculated. The pure water flow rate deviation c2 is given to the PID calculation unit 72. PID calculator 7
2 is a proportional operation (P operation) for determining the pure water flow manipulated variable in proportion to the pure water flow deviation c2 given from the subtractor 71.
And an integral operation (I operation) for determining a pure water flow manipulated variable in proportion to the integral of the pure water flow deviation c2, and a differential operation for determining a pure water flow manipulated variable in proportion to the differentiation of the pure water flow deviation c2. (D
Operation), the pure water flow rate control operation amount that cancels the pure water flow rate deviation c2 is calculated. The operation amount of the pure water flow control is supplied to the adder 74 via the switch 73.

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 begins to flow 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 in order to avoid an overshoot in an initial stage when pure water starts flowing to the pure water supply path 2.

The adder 74 adds the pure water flow target value a2 given by the target value setting unit 30
The pure water flow control operation amount given from the ID calculation unit 72 is added. 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 converter 75 converts the pure water flow rate operation amount d2 given from the adder 74 into the following equation (2).
It is converted to the pure water flow operation voltage Vd2. Vd2 = (d2−Cc) / Dc (2) where 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 The constants Cc and Dc determined by the specifications of the pure water pressure regulator 3 and the resistance coefficient of the pure water supply path 2 can be obtained by experiments.

The pure water flow operation 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 control unit 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 actual value b2. 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.

As described above, according to the first embodiment described above, the pure water pressure fluctuation feedback section 60A corrects the predetermined chemical liquid flow rate 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: Change pattern of target value Chemical liquid flow target value a1 (that is, chemical liquid flow operation voltage Vd
FIG. 4 shows an example of a change pattern of the target value when 1) is made constant and the pure water flow target value a2 is temporally changed. The target value setting unit 30 of the present embodiment is configured such that the supply of the processing liquid into the substrate processing tank 1 filled with pure water is started until the substrate processing tank 1 is completely replaced with the processing liquid. Then, the chemical liquid flow rate target value a1 is set to be constant over time, while the initial target value of the pure water flow rate target value a2 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. By setting such a target value, in the initial stage of replacement, a low-concentration processing liquid is supplied into the substrate processing tank 1 filled with pure water, so that the concentration of the processing liquid in the substrate processing tank 1 is reduced. Unevenness can be reduced. In the graph showing the change in the density unevenness of the processing liquid in the substrate processing tank 1 in FIG. 4, the change in the density unevenness according to the present embodiment is indicated by a solid line, and the density unevenness according to the conventional method of performing the replacement with the processing liquid having a constant concentration is indicated by a chain line. , Respectively.

B: Second Embodiment B1: Configuration of Second Embodiment Apparatus FIG. 5 shows a schematic configuration of a substrate processing apparatus according to this embodiment.
In FIG. 5, the portions indicated by the same reference numerals as those in FIG. 1 have the same configuration as the device of the first embodiment, and thus the description thereof will be omitted. This embodiment is different from the first embodiment in the following points. In the first embodiment, a pure water flow rate sensor 4 is provided in the pure water supply path 2 to provide a pure water flow rate current value b2.
The pure water flow present value b2 is supplied to the pure water pressure fluctuation feedback unit 60A and the pure water flow feedback control unit 70. On the other hand, in the second embodiment, instead of the pure water flow rate sensor 4 directly detecting the pure water flow rate current value b2,
It has the following configuration. A chemical liquid flow rate sensor 18 is provided in the chemical liquid supply path 11 to detect a current chemical liquid flow rate value b1.
Further, a concentration measuring device 100 for measuring the current concentration b3 of the processing liquid is provided between the chemical solution mixing section 5 and the substrate processing tank 1.
Then, the current value of the chemical solution flow rate b1 detected by the chemical solution flow rate sensor 18 and the current value of the processing solution concentration b3 measured by the concentration measuring device 100 are given to the pure water flow rate current value calculation unit 90, and the pure water flow rate current value is given. b2 is obtained by calculation.
Further, a pure water pressure sensor 7 is provided in the pure water supply path 2 to detect a current pure water pressure value e2 of the pure water in the pure water supply path 2 and supply the detected value to a pure water pressure fluctuation feedback unit 60B.

B2: Schematic Configuration of Control System FIG. 6 shows the configuration of the control system of this embodiment. This control system includes a target value setting unit 30, a pure water pressure fluctuation feedback unit 60B, a pure water flow rate feedback control unit 70, and a pure water flow current value calculation unit 90, when functionally distinguished. Among them, the target value setting unit 30 and the pure water flow rate feedback control unit 70 are the same as those of the first embodiment, and thus the description thereof is omitted. Hereinafter, portions different from the first embodiment will be described.

The pure water pressure fluctuation feedback section 60B does not include the pure water pressure current value calculation section 64 as provided in the pure water pressure fluctuation feedback section 60A of the first embodiment.
Is supplied directly to the subtractor 61. Hereinafter, the pure water pressure fluctuation feedback unit 6 of the first embodiment will be described.
Similarly to 0A, the pressure fluctuation value Δe2 is obtained by subtracting the pure water pressure reference value P ₀ from the pure water pressure current value e2,
The pressure fluctuation value Δe2 is converted into a voltage value ΔVe2, and the voltage value ΔVe2 is added to a constant chemical liquid flow rate operation voltage Vd1, thereby suppressing the concentration fluctuation of the processing liquid due to the fluctuation of the pure water pressure.

On the other hand, the pure water flow rate current value calculating section 90 calculates the chemical solution flow rate current value b1 measured by the chemical solution flow rate sensor 18 and the processing solution concentration current value b3 measured by the processing solution concentration measuring device 100. Then, a pure water flow rate current value b2 is calculated using the following equation (3). b2 = b1 × (C ₀ −b3) / (1000 × b3) ……
(3) However, b1 is the current value of the flow rate of the chemical solution [cc / min] b2 is the current value of the pure water flow rate [liter / min] b3 is the current value (actual measurement value) of the treatment liquid [%] C ₀ is API solution concentration [%]

The current pure water flow rate value b2 obtained by the current pure water flow rate calculation section 90 is subtracted from the subtracter 71 of the pure water flow rate feedback control section 70.
Given to. The operation of the pure water flow rate feedback control unit 70 itself is as follows.
Since it is the same as the first embodiment, the description here is omitted.

According to the second embodiment, as in the first embodiment, the pure water pressure fluctuation feedback unit 60B suppresses the concentration fluctuation of the processing liquid caused by the fluctuation of the pure water pressure, and the pure water flow rate feedback control unit. 70 suppresses the fluctuation in the concentration of the processing solution caused by the fluctuation in the flow of the pure water.

C: Third Embodiment C1: Third Embodiment Apparatus Configuration FIG. 7 shows a schematic configuration of a substrate processing apparatus according to the third embodiment.
In FIG. 7, 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 pressure is controlled by the chemical pressure regulator 19 provided in the chemical supply path 11 so that the chemical at a constant flow rate is supplied to the chemical introduction valve 9.
And introduced into the pure water supply path 2. On the other hand, the device of the third embodiment replaces the chemical liquid introduction valve 9, the chemical liquid supply valve 10, and the chemical liquid 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. The valve chamber 21a has a chemical solution inlet 21g.
Is connected to the pure water flow path 12a of the introduction valve connection pipe 12 through the connection. 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 liquid 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.

C2: Schematic Configuration of Control System The configuration of the control system of the apparatus of the present embodiment is substantially the same as that of the first embodiment shown in FIG. 3, and therefore detailed description is omitted here. However, the conversion equation (primary equation for converting the pressure fluctuation value Δe2 of pure water into the correction voltage ΔVe2) used in the pressure-voltage conversion unit 62 is different from that of the first embodiment, and is different from the electropneumatic converter 20 and the chemical solution. It is experimentally determined in consideration of the specifications of the flow control valve 21 and the like.

C3: 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.

When the pure water pressure in the pure water supply path 2 does not fluctuate, a pilot pressure corresponding to the preset chemical liquid flow rate operation voltage Vd1 is given to the chemical liquid flow rate control valve 21, so that a predetermined flow rate of the chemical liquid is controlled. Flows through the chemical liquid supply path 11 and is introduced into pure water in the pure water supply path 2. On the other hand, pure water supply path 2
When the pressure of the pure water in the inside increases, the flow rate of the chemical solution introduced into the pure water decreases. Therefore, the pure water pressure fluctuation feedback unit 60A corrects the chemical flow rate operation voltage Vd1 in a direction to increase the chemical flow rate. 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. Corrected chemical flow rate operation voltage Vd
1 ′ is converted into a pilot pressure by the electropneumatic converter 20 and supplied to the chemical liquid flow rate control valve 21. As a result, pure water supply path 2
When the pure water pressure in the chamber 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 becomes lower than the pure water pressure. When it becomes lower than the value P _0, the opening degree of the chemical liquid flow control valve 21 decreases in accordance with 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.

D: Fourth Embodiment D1: Fourth Embodiment Configuration of Apparatus FIG. 9 shows a schematic configuration of a substrate processing apparatus according to this embodiment.
In FIG. 9, the components indicated by the same reference numerals as those in FIG. 5 have the same configuration as the device of the second embodiment, and thus the description thereof will be omitted. Hereinafter, differences from the second embodiment will be described.

In the apparatus of the second embodiment shown in FIG. 5, the chemical pressure is controlled by the chemical pressure regulator 19 provided in the chemical supply path 11, so that the chemical at a constant flow rate is supplied to the chemical introduction valve 9.
And introduced into the pure water supply path 2. On the other hand, in the device of the fourth embodiment, instead of the chemical liquid introduction valve 9, the chemical liquid supply valve 10, and the chemical liquid pressure regulator 19 of the third embodiment,
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 configuration of the chemical liquid flow control valve 21 is the same as that described in the third embodiment, and a description thereof will be omitted.

D2: Schematic Configuration of Control System The configuration of the control system of the apparatus of this embodiment is almost the same as that of the second embodiment shown in FIG. 6, and a detailed description thereof will be omitted. However, as in the third embodiment, the conversion equation (primary equation for converting the pressure fluctuation value Δe2 of pure water into the correction voltage ΔVe2) used in the pressure-voltage conversion unit 62 is different from that of the second embodiment. , Is experimentally determined in consideration of the specifications of the electropneumatic converter 20 and the chemical liquid flow control valve 21.

In the operation of this embodiment, the chemical flow rate in the chemical supply passage 11 is controlled by operating the valve opening of the chemical flow control valve 21 by the pilot pressure based on the corrected chemical flow rate operation voltage Vd1 '. Except for this point, the operation is the same as that of the second embodiment, and the description is omitted here.

In the first embodiment and the second embodiment, as shown in FIG. 2, the chemical liquid introduction valve 9 is connected to the introduction valve connecting pipe 12 interposed in the pure water supply path 2, and the third embodiment is used. In the example and the fourth embodiment, as shown in FIG. 8, the chemical liquid flow rate control valve 21 is connected to the introduction valve connection 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.

[0074]

As apparent from the above description, the present invention has the following effects. According to the first and second aspects of the present invention, the pure water flowing in the pure water supply path is adjusted by adjusting the pure water pressure in the pure water supply path according to the fluctuation of the pure water flow rate in the pure water supply path. The water flow is kept constant. Therefore, according to the first and second aspects of the present invention, even when the flow path resistance of the pure water supply path changes,
Since the flow rate of pure water flowing through the pure water supply path is always kept constant, fluctuations in the concentration of the processing solution due to fluctuations in the flow rate of pure water can be suppressed.

According to a third aspect of the present invention, the chemical pressure in the chemical supply path is adjusted in accordance with the fluctuation of the pure water pressure in the pure water supply path, thereby reducing the chemical pressure on the inlet side of the chemical introduction valve. ,
Maintain a constant pressure difference from the pure water pressure on the outlet side. Therefore, according to the present invention, the amount of the chemical solution introduced into the pure water is always constant even if the pure water pressure fluctuates. The fluctuation in the concentration of the treated solution can also be suppressed.

According to a fourth aspect of the present invention, the flow rate of the chemical in the chemical supply path is kept constant by operating the valve opening of the chemical flow control valve in accordance with the fluctuation of the pure water pressure in the pure water supply path. To maintain. Therefore, according to the present invention, the amount of the chemical solution introduced into the pure water is always constant even if the pure water pressure fluctuates. The fluctuation in the concentration of the treated solution can also be suppressed.

According to the fifth and sixth aspects of the present invention, since the present pure water pressure value is obtained by calculation,
There is no need to provide a sensor for measuring the pure water pressure.

According to the seventh aspect of the present invention, since the pure water flow rate target value that changes with time is set,
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 present invention, in the initial stage of supplying the processing liquid into the substrate processing unit filled with pure water, the target value of the pure water flow rate is set high,
Since the processing liquid having a relatively low concentration is supplied to the substrate processing unit, it is possible to suppress unevenness in the concentration of the processing liquid in the substrate processing unit.

According to the ninth aspect of the present invention, since the present value of the pure water flow rate is obtained by calculation, there is no need to provide a sensor for measuring the pure water flow rate.

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

FIG. 5 is a diagram illustrating a schematic configuration of a substrate processing apparatus according to a second embodiment of the present invention.

FIG. 6 is a block diagram functionally showing a control system according to a second embodiment.

FIG. 7 is a diagram illustrating a schematic configuration of a substrate processing apparatus according to a third embodiment.

FIG. 8 is a cross-sectional view showing the structure of a chemical liquid flow control valve.

FIG. 9 is a diagram illustrating a schematic configuration of a substrate processing apparatus according to a fourth embodiment.

[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 DESCRIPTION OF SYMBOLS 21 ... Chemical liquid flow control valve 30 ... Target value setting part 31 ... Variable designation part 32 ... Target value output part 60A, 60B ... Pure water pressure fluctuation feedback part 61 ... Subtractor 62 ... Pressure-voltage conversion part 63 ... Adder 64 ... Pure water pressure current value calculation unit 70: Pure water flow rate feedback control unit 71: Subtractor 72 ... PID calculation unit 73 ... Switch 74 ... Adder 75 ... Flow-voltage conversion unit 90 ... Pure water flow current value calculation unit a2: Pure Water flow target value b1 ... Current value of chemical liquid flow b ... Pure water flow current value b3 ... Treatment liquid concentration current value c2 ... Pure water flow deviation d2 ... Pure water flow operation amount Vd1 ... Chemical liquid flow operation voltage Vd1 '... Corrected chemical liquid flow operation voltage Vd2 ... Pure water flow operation voltage e2: Pure water pressure present value P ₀ : Pure water pressure reference value

Claims (9)

[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 introduction 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 predetermined chemical solution flow rate operation amount set in advance in relation to a concentration target value of the processing solution. A chemical liquid pressure regulator for adjusting the chemical liquid pressure in the chemical liquid supply path; Target value setting means for setting a pure water flow target value of pure water to be circulated to the pure water supply passage upstream of a position where a chemical solution is introduced into the pure water supply passage; Based on the operation amount, a pure water pressure regulator that adjusts the pure water pressure in the pure water supply path, a pure water flow rate target value given from the target value setting means,
A pure water flow deviation calculating means for calculating a deviation from the pure water flow current value, and a pure water flow manipulated variable that cancels the pure water flow deviation is calculated. And a pure water flow rate feedback control means including a pure water flow operation amount calculation means to be provided. 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 chemical liquid supply path connected in the middle of the path, a chemical liquid pressure feeding means for sending the chemical liquid in the chemical liquid tank to the chemical liquid supply path, and a predetermined chemical liquid flow rate operation amount preset in relation to a target concentration of the processing liquid. A chemical liquid flow rate control valve for adjusting the chemical liquid flow rate in the chemical liquid supply path by manipulating the opening degree of the valve based on the target, and a target for setting a pure water flow target value of pure water flowing through the pure water supply path. Value setting means, and a position at which a chemical solution is introduced into the pure water supply path. A pure water pressure regulator disposed in the pure water supply path on the upstream side and for adjusting a pure water pressure in the pure water supply path based on a pure water flow rate operation amount; Pure water flow rate target value,
A pure water flow deviation calculating means for calculating a deviation from the pure water flow current value, and a pure water flow manipulated variable that cancels the pure water flow deviation is calculated. And a pure water flow rate feedback control means including a pure water flow operation amount calculation means to be provided. 3. The apparatus according to claim 1, wherein the apparatus further obtains a pure water pressure current value in the pure water supply path, and the pure water pressure current value is a predetermined pure water pressure reference value. When it is higher than the above, when the chemical liquid flow rate operation amount is corrected in the direction of increasing the chemical liquid pressure and given to the chemical liquid pressure regulator, when the pure water pressure current value becomes lower than the pure water pressure reference value, A pure water pressure fluctuation feedback unit that corrects the chemical liquid flow rate operation amount in the direction of lowering the chemical liquid pressure and gives it to the chemical liquid pressure regulator, wherein the pure water pressure fluctuation feedback unit comprises pure water in the pure water supply path. Pure water pressure detecting means for actually measuring the current pressure value, by comparing the actually measured pure water pressure current value with a predetermined pure water pressure reference value, the pressure fluctuation value of the pure water pressure current value Means for calculating the pure water pressure fluctuation value to be obtained; Is added to the drug solution flow rate operation amount a substrate processing apparatus including a pure water pressure fluctuation value adding means for providing the liquid chemical pressure regulator. 4. The apparatus according to claim 2, wherein the apparatus further obtains a pure water pressure current value in the pure water supply path, and the pure water pressure current value is a predetermined pure water pressure reference value. When it becomes higher, the chemical liquid flow rate operation amount is corrected in the direction of increasing the chemical liquid flow rate and given to the chemical liquid flow rate control valve, and when the pure water pressure current value becomes lower than the pure water pressure reference value, A pure water pressure fluctuation feedback unit that corrects a chemical liquid flow rate operation amount in a direction to decrease the chemical liquid flow rate and gives it to the chemical liquid flow rate control valve, wherein the pure water pressure fluctuation feedback unit comprises pure water in the pure water supply path. Pure water pressure detecting means for actually measuring the current pressure value, by comparing the actually measured pure water pressure current value with a predetermined pure water pressure reference value, the pressure fluctuation value of the pure water pressure current value Means for calculating the pure water pressure fluctuation value to be obtained; A substrate processing apparatus including a pure water pressure fluctuation value adding means for providing adds a serial drug solution flow rate operation amount to the chemical flow rate control valve. 5. The apparatus according to claim 1, wherein the apparatus further obtains a pure water pressure current value in the pure water supply path, and the pure water pressure current value is a predetermined pure water pressure reference value. When it is higher than the above, when the chemical liquid flow rate operation amount is corrected in the direction of increasing the chemical liquid pressure and given to the chemical liquid pressure regulator, when the pure water pressure current value becomes lower than the pure water pressure reference value, A pure water pressure fluctuation feedback unit that corrects the chemical liquid flow rate operation amount in the direction of lowering the chemical liquid pressure and gives it to the chemical liquid pressure regulator, wherein the pure water pressure fluctuation feedback unit comprises pure water in the pure water supply path. Pure water pressure calculation means for calculating the pure water pressure current value based on the flow rate current value by calculation, and comparing the calculated pure water pressure current value with a predetermined pure water pressure reference value, Pure water pressure fluctuation value to obtain the pressure fluctuation value of the current water pressure value The substrate processing apparatus comprising: means exits, and a pure water pressure fluctuation value adding means for providing the pure water pressure variation in the chemical pressure regulator adds to the chemical flow operation amount. 6. The apparatus according to claim 2, wherein the apparatus further obtains a pure water pressure current value in the pure water supply path, and the pure water pressure current value is a predetermined pure water pressure reference value. When it becomes higher, the chemical liquid flow rate operation amount is corrected in the direction of increasing the chemical liquid flow rate and given to the chemical liquid flow rate control valve, and when the pure water pressure current value becomes lower than the pure water pressure reference value, A pure water pressure fluctuation feedback unit that corrects a chemical liquid flow rate operation amount in a direction to decrease the chemical liquid flow rate and gives it to the chemical liquid flow rate control valve, wherein the pure water pressure fluctuation feedback unit comprises pure water in the pure water supply path. Pure water pressure calculation means for calculating the pure water pressure current value based on the flow rate current value by calculation, and comparing the calculated pure water pressure current value with a predetermined pure water pressure reference value, Pure water pressure fluctuation to obtain the pressure fluctuation value of the current water pressure Calculation means and a substrate processing apparatus including a pure water pressure fluctuation value addition means for the pure water pressure variation value by adding the drug solution flow rate operation amount applied to the chemical flow rate control valve. 7. The substrate processing apparatus according to claim 1, wherein the target value setting unit sets a pure water flow target value that changes with time. 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 for setting an initial target value of a pure water flow rate target value higher than a subsequent target value. 9. The pure water flow rate calculating means according to claim 1, wherein said apparatus further calculates a pure water flow rate current value based on a current value of the chemical solution flow rate and a current concentration value of the processing solution. A substrate processing apparatus for providing the calculated pure water flow rate current value to the pure water flow rate deviation calculating means.