JP2019192863A - Substrate processing apparatus and substrate processing method - Google Patents

Abstract

To provide a substrate processing apparatus capable of reducing a processing liquid amount used in a concentration control.SOLUTION: A substrate processing apparatus is a substrate processing apparatus performing a prescribed processing to a substrate by ejecting a processing liquid containing a medicinal solution and a pure water to the substrate. The substrate processing apparatus comprises: a medicinal solution supply part that supplies the medicinal solution containing a prescribed component; a pure water supply part that supplies the pure water; an accumulation tank that accumulates the processing liquid of which a concentration of the prescribed component is lower than that of the medicinal solution by containing the medicinal solution supplied from the medicinal solution supply part and the pure water supplied from the pure water supply part; a substrate processing part that executes the prescribed processing to the substrate by ejecting the processing liquid to the substrate; a supply pipe that becomes a flow channel of the processing liquid from the accumulation tank to the substrate processing part; and a collection pipe that returns the processing liquid ejected to the substrate in the substrate processing part to the accumulation tank. The medicinal solution supply part supplies the medicinal solution to the accumulation tank in accordance with the prescribed processing, and thereby suppressing the deterioration of the concentration of the processing liquid.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a substrate processing apparatus and a substrate processing method for discharging a processing liquid to a substrate such as a semiconductor wafer and performing an etching process and a cleaning process.

  In the substrate processing apparatus, as a substrate processing preparation, a processing liquid having a predetermined concentration is supplied to a tank of the substrate processing apparatus, and the supplied processing liquid is stored in the tank. The manufacturing process of a semiconductor device includes a process of performing an etching process, a cleaning process, or the like on the substrate by discharging a processing liquid stored in a tank of the substrate processing apparatus to the substrate. The discharged processing liquid is collected in a tank and reused for processing the substrate. By reusing the processing liquid, the consumption of the processing liquid is reduced.

  If the reuse of the processing liquid is continued, the concentration of the processing liquid may decrease with the passage of time due to evaporation, decomposition, or the like of the processing liquid constituent components. Therefore, concentration control is performed to maintain the concentration of the processing liquid within a range appropriate for the etching process and the cleaning process. Concentration control is performed, for example, by replenishing a tank with a processing solution having a predetermined concentration. If the concentration of the treatment liquid cannot be maintained within the appropriate range for the above-described etching process or cleaning process even by the concentration control, the entire treatment liquid is exchanged.

Japanese Patent Laying-Open No. 2015-177139

  Conventionally, the concentration of the processing liquid to be replenished in the tank in the concentration control is the same as the concentration of the processing liquid stored in the tank in the preparation for processing, so the concentration of the processing liquid in the tank is in a range suitable for each of the above processes. In order to maintain the inside, it was necessary to replenish a large amount of the processing solution in the concentration control.

  Thus, one aspect of the disclosed technique is to reduce the amount of processing liquid used in the concentration control of the processing liquid in the substrate processing apparatus.

  One aspect of the disclosed technology is exemplified by the following substrate processing apparatus. This substrate processing apparatus is a substrate processing apparatus that performs a predetermined process on a substrate by discharging a processing liquid containing a chemical solution and pure water onto the substrate. The substrate processing apparatus includes a chemical solution supply unit that supplies a chemical solution containing a predetermined component, a pure water supply unit that supplies pure water, a chemical solution supplied from the chemical solution supply unit, and pure water supplied from the pure water supply unit. A storage tank for storing a processing liquid having a concentration of a predetermined component lower than that of the chemical liquid, a substrate processing unit for executing a predetermined processing on the substrate by discharging the processing liquid to the substrate, and storage A supply pipe that serves as a flow path for the processing liquid from the tank to the substrate processing unit, and a recovery pipe that returns the processing liquid discharged to the substrate in the substrate processing unit to the storage tank. By supplying the chemical liquid to the storage tank as the process progresses, the concentration of the processing liquid is suppressed from decreasing.

In the disclosed technology, by containing a chemical solution containing a predetermined component and pure water, a treatment liquid having a concentration of the predetermined component lower than that of the chemical solution is stored in a storage tank. The substrate processing unit performs a predetermined process on the substrate by discharging a processing liquid onto the substrate. The processing liquid discharged to the substrate in the substrate processing unit is returned to the storage tank via the recovery pipe, and is reused for the predetermined processing. Continuing the reuse of the treatment liquid may reduce the concentration of the treatment liquid, but the treatment liquid has a lower concentration of certain components than the chemical liquid, so the reuse of the treatment liquid is more than when using the chemical liquid as it is. The decrease in concentration due to is moderate. Moreover, since the density | concentration of the predetermined component in a process liquid is low, the density | concentration of the process liquid stored in a storage tank can be raised by supply of a small amount of chemical | medical solutions. Therefore, according to the disclosed technique, it is possible to reduce the amount of processing liquid used for concentration control. The supply of the chemical solution may be performed, for example, every time the substrate processing unit performs a predetermined number of predetermined processes on the substrate, or is performed when the cumulative execution time of the predetermined processing by the substrate processing unit reaches a predetermined time. May be.

  The disclosed technology further includes a circulation pipe serving as a flow path from the middle of the supply pipe to the storage tank, and the circulation pipe includes a concentration meter that measures the concentration of the chemical in the processing liquid flowing in the circulation pipe. It may be provided. The concentration accuracy of the densitometer decreases when bubbles are generated in the processing liquid that is the target of concentration measurement. Bubbles are likely to occur in places where there is no flow of processing liquid or where the processing liquid and gas are in contact. Since there is a flow of the processing liquid in the circulation pipe and the processing liquid and the gas are not in contact with each other, it is suitable for installing a concentration meter, and a decrease in measurement accuracy of the concentration meter is suppressed.

  In the disclosed technology, the circulation pipe is further provided with a waste liquid pipe for discharging the processing liquid flowing in the circulation pipe, and when the concentration indicated by the densitometer falls below the concentration range suitable for the predetermined treatment, the waste liquid pipe is provided. A predetermined amount of the processing liquid may be discharged from the liquid and the chemical liquid supply unit may supply a predetermined amount of the chemical liquid to the storage tank. According to such a technique, the concentration of the treatment liquid can be easily recovered by discharging the treatment liquid having a reduced concentration and then replenishing the chemical liquid.

  In the disclosed technology, the pure water supply unit may further execute a process of supplying pure water to the storage tank when the concentration indicated by the densitometer exceeds a concentration range suitable for a predetermined process. According to such a technique, the concentration of the treatment liquid in which the concentration of the predetermined component is too high can be lowered.

  The disclosed technology further includes a return pipe that is connected to the substrate processing unit side from the middle of the supply pipe and returns the processing liquid to the storage tank. The inner diameter of the circulation pipe is larger than the inner diameter of the return pipe. It may be formed thin. Since the inner diameter of the circulation pipe is smaller than the inner diameter of the return pipe, the flow rate of the processing liquid flowing in the return pipe is smaller than the flow rate of the process liquid flowing in the return pipe. Therefore, it is possible to reduce the amount of processing liquid that flows through the circulation pipe for concentration measurement.

  In the disclosed technology, a heating unit that heats the processing liquid flowing in the supply pipe is provided on the supply pipe closer to the storage tank than in the middle of the pipe line, and the heating unit is higher than when the chemical liquid is used for a predetermined process. The treatment liquid may be heated to a temperature. The processing efficiency for the substrate depends on the concentration of the predetermined component in the processing liquid and the temperature of the processing liquid. The processing liquid may have a lower processing efficiency for the substrate due to a lower concentration of the predetermined component than the chemical liquid. According to the technique of an indication, the fall of process efficiency is suppressed by heating the temperature of a process liquid to the temperature higher than the case where a chemical | medical solution is used for a process.

In the disclosed technology, the storage tank includes a first storage tank and a second storage tank, and the supply pipe is a first supply pipe that serves as a flow path for the processing liquid between the first storage tank and the substrate processing unit. And a second supply pipe that serves as a flow path for the processing liquid between the second storage tank and the first storage tank, and the circulation pipe passes from the middle of the first pipeline of the first supply pipe to the first storage tank. And a second circulation pipe serving as a flow path from the middle of the second pipe of the second supply pipe to the second storage tank, and the heating means is provided in the first supply pipe. A first heating unit that is provided closer to the first storage tank than in the middle of the first pipe and heats the processing liquid flowing in the first supply pipe, and a second storage tank in the second supply pipe than in the middle of the second pipe. And a second heating means for heating the processing liquid flowing in the second supply pipe, the second heating means being higher than the first heating means. Temperature in the processing liquid may be heated. Since the second heating unit heats the processing liquid at a temperature higher than that of the first heating unit, the temperature adjustment in the second storage tank is adjusted to a temperature suitable for the substrate processing in a shorter time. Since the processing liquid adjusted to a temperature suitable for processing is supplied from the second storage tank to the first storage tank, the second heating means is used for temperature adjustment of the processing liquid supplied from the first storage tank to the substrate processing unit. It is sufficient to finely adjust the temperature of the treatment liquid by the first heating means set to a lower temperature. According to such a technique, the processing liquid can be adjusted to a temperature suitable for processing in a shorter time, and the temperature of the processing liquid supplied to the substrate processing unit can be controlled with high accuracy.

  In the disclosed technology, the second heating unit includes a plurality of heating units disposed along the second supply pipe, and is disposed next to any one heating unit and the one heating unit among the plurality of heating units. And a thermometer that measures the temperature of the processing liquid that is inserted between the heated portion and flows in the second supply pipe, and based on the measurement result of the thermometer, the first storage tank side. The temperature of the heating unit arranged in the may be controlled. A thermometer interposed between any one of the plurality of heating units and a heating unit disposed next to the one heating unit is disposed closer to the second storage tank than the thermometer. The temperature of the treatment liquid heated by the heating unit is measured. Based on the measurement result, the temperature of the processing liquid can be finely controlled by controlling the heating unit disposed on the side of the one storage tank relative to the thermometer.

  In the disclosed technology, the chemical solution supply unit may supply the chemical solution to the second storage tank, and the pure water supply unit may supply pure water to the second storage tank. By making the supply destination by the chemical solution supply unit and the pure water supply unit the second storage tank, changes in the concentration and temperature of the processing liquid stored in the first storage tank are suppressed.

  In the disclosed technology, the predetermined component included in the chemical solution may include hydrofluoric acid. Hydrofluoric acid is suitable for etching the substrate. The disclosed technology can also be understood from the side of the substrate processing method executed in the substrate processing apparatus.

  According to the disclosed technique, in the substrate processing apparatus, it is possible to reduce the amount of the processing liquid used for controlling the concentration of the processing liquid.

FIG. 1 is a diagram illustrating an example of a configuration of a substrate processing apparatus according to an embodiment. FIG. 2 is an example of a functional block diagram of the substrate processing apparatus. FIG. 3 is a diagram illustrating an example of a configuration in which an integrating flow meter is provided in the recovery pipe and the processing chamber. FIG. 4 is a diagram illustrating an example of a configuration of a substrate processing apparatus including a plurality of processing chambers. FIG. 5 is a diagram illustrating an example of a change in the concentration of a predetermined component in the processing liquid when temperature adjustment is performed without processing the substrate. FIG. 6 is a diagram illustrating an example of a change in the concentration of a predetermined component in the processing liquid when the substrate is processed while the processing liquid is reused. FIG. 7 is a diagram illustrating an example of the configuration of the substrate processing apparatus according to the embodiment. FIG. 8 is a first diagram illustrating an example of the piping operation of the substrate processing apparatus during the preparation of the processing liquid. FIG. 9 is a second diagram illustrating an example of the piping operation of the substrate processing apparatus during the preparation of the processing liquid. FIG. 10 is a third diagram illustrating an example of the piping operation of the substrate processing apparatus during the preparation of the processing liquid. FIG. 11 is a fourth diagram illustrating an example of the piping operation of the substrate processing apparatus during the preparation of the processing liquid. FIG. 12 is a fifth diagram illustrating an example of the piping operation of the substrate processing apparatus during the preparation of the processing liquid. FIG. 13 is a sixth diagram illustrating an example of the piping operation of the substrate processing apparatus during the preparation of the processing liquid. FIG. 14 is a first diagram illustrating an example of a piping operation of a substrate processing apparatus that performs processing on a substrate. FIG. 15 is a second diagram illustrating an example of a piping operation of a substrate processing apparatus that performs processing on a substrate. FIG. 16 is a third diagram illustrating an example of a piping operation of a substrate processing apparatus that performs processing on a substrate. FIG. 17 is a fourth diagram illustrating an example of a piping operation of a substrate processing apparatus that performs processing on a substrate. FIG. 18 is a fifth diagram illustrating an example of a piping operation of a substrate processing apparatus that performs processing on a substrate. FIG. 19 is a sixth diagram illustrating an example of a piping operation of a substrate processing apparatus that performs processing on a substrate.

  Hereinafter, a substrate processing apparatus and a substrate processing method using the substrate processing apparatus according to an embodiment will be described with reference to the drawings. The configuration of the embodiment described below is an exemplification, and the disclosed technology is not limited to the configuration of the embodiment.

<Embodiment>
FIG. 1 is a diagram illustrating an example of a configuration of a substrate processing apparatus 1 according to the embodiment. The substrate processing apparatus 1 mainly performs an etching process or a cleaning process (hereinafter also simply referred to as “processing”) on a substrate W such as a semiconductor wafer. The substrate processing apparatus 1 is an apparatus of a type that processes the substrates W one by one, and is a so-called sheet type substrate processing apparatus. Hereinafter, the configuration of the substrate processing apparatus 1 will be described with reference to FIG. Processing such as etching processing and cleaning processing on the substrate W is an example of “predetermined processing”.

  The processing chamber 11 performs processing by discharging a processing liquid to the substrate W. The processing chamber 11 includes a table 111 on which the substrate W is placed, a discharge port 112, and a wall 113. The table 111 is formed in a substantially cylindrical shape, and can be rotated by placing a substrate W to be processed. The discharge port 112 discharges the processing liquid to the substrate W placed on the table. The periphery of the table 111 is surrounded by a wall 113, and scattering of the processing liquid discharged onto the substrate W is suppressed. The processing chamber 11 is an example of a “substrate processing unit”.

  Pure water is stored in the pure water supply source 17. The pure water supply source 17 is connected to a pure water supply pipe 25 that serves as a pure water flow path to the tank 12. The pure water supply pipe 25 is provided with an opening / closing valve 31a (for example, a gate valve), an adjustment valve 32a (for example, a needle valve), and an instantaneous flow meter 33a (for example, an ultrasonic flow meter) in this order. Supply of pure water to the tank 12 is started by opening the valve 31a, and supply of pure water to the tank 12 is stopped by closing the on-off valve 31a. The flow rate of pure water supplied from the pure water supply source 17 to the tank 12 is controlled by the regulating valve 32a. The instantaneous flow meter 33 a measures the flow rate per unit time of pure water flowing through the pure water supply pipe 25. The pure water supply source 17 is an example of a “pure water supply unit”.

The chemical solution supply source 18 stores a chemical solution containing a predetermined component at a predetermined replenishment concentration (for example, 49%). A chemical solution supply pipe 26 serving as a chemical solution flow path to the tank 12 is connected to the chemical solution supply source 18. The chemical solution supply pipe 26 is provided with an on-off valve 31b, an adjustment valve 32b, and an instantaneous flow meter 33b from the tank 12 side. When the on-off valve 31b is opened, supply of the chemical solution to the tank 12 is started. The supply of the chemical solution to the tank 12 is stopped by closing the on-off valve 31b. The flow rate of the chemical liquid supplied from the chemical liquid supply source 18 to the tank 12 is controlled by the adjustment valve 32b. The instantaneous flow meter 33b measures the flow rate per unit time of the chemical liquid flowing through the chemical liquid supply pipe 26. The chemical solution supplied to the tank 12 by the chemical solution supply source 18 is, for example, a hydrofluoric acid aqueous solution containing hydrofluoric acid (hydrofluoric acid) as a predetermined component. The chemical solution supply source 18 is an example of a “chemical solution supply unit”.

  The tank 12 stores a processing liquid used for processing. The tank 12 contains a predetermined component having an initial concentration (for example, 40%) lower than the replenishment concentration by diluting the chemical solution supplied from the chemical solution supply source 18 with pure water supplied from the pure water supply source 17. The processing liquid is stored. The processing efficiency for the substrate W (for example, the etching rate when the processing is etching) depends on the concentration of the predetermined component in the processing liquid and the temperature of the processing liquid. That is, considering the processing efficiency for the substrate W, it is preferable that the concentration of the predetermined component in the processing liquid is high. However, in this embodiment, in order to reduce the amount of processing liquid used in concentration control described later, the processing liquid stored in the tank 12 is diluted to an initial concentration lower than that of the chemical liquid by diluting the chemical liquid with pure water. Concentration is controlled. The decrease in processing efficiency due to the lowering of the concentration is because the temperature of the processing liquid is adjusted to a temperature higher than that in the case of using the chemical liquid as it is for the processing (that is, when the chemical liquid having the above-mentioned replenishment concentration is used in the processing). Is suppressed. The tank 12 is provided with a liquid level sensor 121 that detects the liquid level of the processing liquid in the tank 12. When the liquid level sensor 121 detects the height of the liquid level, the amount of the processing liquid stored in the tank 12 can be determined. That is, by detecting the liquid level height with the liquid level sensor 121, the liquid level is the “quantitative” position that is normally stored in the tank 12, or the amount that should be replenished. The “replenishment start” position, or the “overflow” position indicating that the processing liquid overflows from the tank when the processing liquid is further supplied to the tank, or the “lower limit” indicating the lower limit of the processing liquid stored in the tank Can be determined. The tank 12 is an example of a “storage tank”.

  The supply pipe 21 is a pipe having an inner diameter of about 25 mm that connects a processing liquid supply source and a processing liquid supply destination. In FIG. 1, a tank 12 that is a supply source of processing liquid and a processing chamber 11 that is a supply destination of processing liquid are connected by a supply pipe 21. The supply pipe 21 is provided with a heater 13 and a pump 14 for heating the processing liquid flowing in the supply pipe 21. The processing liquid adjusted to a temperature suitable for processing by the heater 13 is pumped to the processing chamber 11 through the supply pipe 21 by the pump 14. A tank waste liquid pipe 24 having an opening / closing valve 31f is provided at the bottom of the tank 12, and when the entire liquid replacement of the processing liquid stored in the tank 12 is performed, the opening / closing valve 31f is opened and the tank waste liquid is discharged. The processing liquid in the tank 12 is drained (discharged) through the pipe 24. The supply pipe 21 is an example of a “supply pipe”.

  The circulation pipe 22 is a pipe that has one end connected to the middle 21 p of the supply pipe 21 and the other end connected to the tank 12. The circulation pipe 22 is a pipe thinner than the supply pipe 21. For example, the inner diameter of the circulation pipe 22 is about 6 mm. In the supply pipe 21, the heater 13 is provided closer to the tank 12 than the middle pipe 21 p to which the circulation pipe 22 is connected. Therefore, the processing liquid heated by the heater 13 flows into the circulation pipe 22. The heater 13 is an example of a “heating means”.

  The recovery pipe 23 is a pipe that has one end connected to the processing chamber 11 and the other end connected to the tank 12. The recovery pipe 23 serves as a flow path for returning the processing liquid used for processing in the processing chamber 11 to the tank 12. That is, the processing liquid used for processing in the processing chamber 11 is recovered in the tank 12 via the recovery pipe 23. The recovery pipe 23 is an example of “recovery pipe”.

The thermometer 15 is provided in the circulation pipe 22. As described above, since the processing liquid heated by the heater 13 flows into the circulation pipe 22, the thermometer 15 can measure the temperature of the processing liquid heated by the heater 13.

The concentration meter 16 is provided in the circulation pipe 22 and measures the concentration of a predetermined component in the processing liquid. The densitometer 16 is reduced in measurement accuracy when bubbles are mixed in the treatment liquid to be measured for concentration. Bubbles in the processing liquid are likely to occur at locations where the processing liquid does not flow or where the processing liquid and gas are in contact. Therefore, in the present embodiment, the densitometer 16 is provided in the circulation pipe 22 in which the processing liquid flows and the processing liquid and the gas do not come into contact with each other. The densitometer 16 measures, for example, the concentration of hydrofluoric acid in the treatment liquid based on the conductivity. For example, a hydrofluoric acid concentration monitor HF-960EM manufactured by Horiba, Ltd. can be used.

  In the supply pipe 21, the on-off valve 31e is a valve provided closer to the processing chamber 11 than the middle 21p of the pipe line, and is, for example, a gate valve. By closing the on-off valve 31e, the flow path of the processing liquid from the tank 12 to the processing chamber 11 is closed, and by opening the on-off valve 31e, the processing liquid from the tank 12 to the processing chamber 11 is opened. The flow path is opened.

  The circulation pipe 22 is provided with a pipe waste liquid pipe 27 that is used as a drain of the processing liquid flowing in the circulation pipe 22. The pipe waste liquid pipe 27 is connected to the tank 12 side from the thermometer 15 and the concentration meter 16 in the circulation pipe 22. The circulation pipe 22 is provided with an on-off valve 31c on the tank 12 side of the circulation pipe 22 from the position where the pipe waste liquid pipe 27 is connected. The pipe waste liquid pipe 27 is provided with an on-off valve 31 d, and the processing liquid flowing through the circulation pipe 22 is drained through the pipe waste liquid pipe 27 by opening the on-off valve 31 d. When draining through the pipe waste liquid pipe 27, the on-off valve 31c is closed to close the flow path to the tank 12, and the on-off valve 31e is closed to close the flow path to the processing chamber 11. To do. As described above, since the inner diameter of the circulation pipe 22 is narrower than that of the supply pipe 21, the flow rate of the processing liquid flowing in the circulation pipe 22 is smaller than the flow rate of the processing liquid flowing in the supply pipe 21. Therefore, by providing the pipe waste liquid pipe 27 in the circulation pipe 22, it becomes easier to control the amount of the processing liquid to be drained than when the pipe waste liquid pipe 27 is provided in the supply pipe 21. The pipe waste liquid pipe 27 is an example of “waste liquid pipe”.

<Functional block>
FIG. 2 is an example of a functional block diagram of the substrate processing apparatus 1. The processing chamber 11, the tank 12, the heater 13, the pure water supply source 17, and the chemical solution supply source 18 are comprehensively controlled by the control unit 55. In addition, the control unit 55 acquires measurement results obtained by the thermometer 15 and the densitometer 16. The configuration of the control unit 55 as hardware is the same as that of a general computer. That is, the control unit 55 stores a CPU 551 that performs various arithmetic processes, a ROM 552 that is a read-only memory that stores basic programs, a RAM 553 that is a readable / writable memory that stores various information, and control applications and data. It is equipped with a magnetic disk. In the present embodiment, the CPU 551 of the control unit 55 executes a predetermined program P, thereby performing temperature adjustment of the processing liquid, execution of processing on the substrate W by the processing chamber 11, control of the processing liquid concentration, and level replenishment. Is done. The program P is stored in the storage unit 57.

<Temperature adjustment>
The temperature adjustment is a process of adjusting the temperature of the processing liquid stored in the tank 12 to a temperature suitable for the process. In the temperature adjustment, the processing liquid pumped from the tank 12 to the supply pipe 21 by the pump 14 is heated by the heater 13 provided in the supply pipe 21. The heated processing liquid is returned to the tank 12 via the circulation pipe 22. By repeating such circulation, the temperature of the processing liquid stored in the tank 12 is adjusted to a temperature suitable for processing. As described above, since the processing efficiency of the substrate W changes in relation to the temperature and concentration of the processing liquid, in the temperature adjustment according to the present embodiment, the temperature is higher than a suitable temperature when using a chemical solution with a replenishment concentration. The temperature of the processing liquid stored in the tank 12 is adjusted to the temperature. By adjusting the treatment liquid to a high temperature, it is possible to avoid a decrease in treatment efficiency even if a treatment liquid having an initial concentration lower than the replenishment concentration is used.

  In the temperature adjustment, the flow path of the processing liquid to the processing chamber 11 is closed by closing the on-off valve 31e. The processing liquid pumped from the tank 12 to the supply pipe 21 is heated by the heater 13 provided in the supply pipe 21, and the heated processing liquid flows into the circulation pipe 22. The processing liquid flowing through the circulation pipe 22 is returned to the tank 12 after the temperature is measured by the thermometer 15. Such circulation is repeated until the temperature measured by the thermometer 15 falls within a temperature range suitable for processing the substrate W. The circulation pipe 22 is also provided with the concentration meter 16 as described above, and the concentration meter 16 measures the concentration of a predetermined component of the processing liquid flowing through the circulation pipe 22. When the temperature measured by the thermometer 15 in the temperature adjustment falls within a temperature range suitable for the processing of the substrate W, the on-off valve 31e is opened, and supply of the processing liquid stored in the tank 12 to the processing chamber 11 is started. The

<Processing of substrate W>
As described above, the processing chamber 11 performs processing by discharging the processing liquid supplied from the tank 12 to the substrate W from the discharge port 112. Here, in the manufacturing process of the substrate W such as a semiconductor wafer, for example, a single crystal ingot such as silicon is sliced in the rod axis direction, and the obtained product is subjected to processes such as chamfering, lapping, etching, and polishing. It is given sequentially. As a result, a plurality of layers, structures, and circuits made of different materials are formed on the surface of the substrate W. The processing of the substrate W performed in the processing chamber 11 is performed, for example, for the purpose of removing metal such as tungsten remaining on the substrate W, and is performed by discharging a processing liquid onto the substrate W. In the processing chamber 11, a substrate W to be processed is placed on the table 111, and the substrate W placed on the table 111 rotates as the table 111 rotates. The processing chamber 11 performs processing on the substrate W by discharging the processing liquid from the discharge port 112 to the rotating substrate W. Scattering of the processing liquid used for the processing is suppressed by the wall 113 surrounding the periphery of the table 111, and the processing liquid used for the processing is stored in a region 113 a surrounded by the wall 113. The processing liquid stored in the region 113 a is recovered in the tank 12 through a recovery pipe 23 that connects the processing chamber 11 and the tank 12. That is, the processing liquid used for the processing is recovered in the tank 12 through the recovery pipe 23 and is reused as the processing liquid supplied to the processing chamber 11. While the processing liquid is being supplied to the processing chamber 11, a part of the processing liquid flows into the circulation pipe 22 via the pipe line 21 p and the temperature measurement by the thermometer 15 and the concentration measurement by the densitometer 16 are continued. Done.

  In the substrate processing apparatus 1, the processing liquid used for processing the substrate W is reused to reduce the consumption of the processing liquid. However, when such reuse of the processing liquid is repeated, the concentration of the predetermined component in the processing liquid may change due to evaporation, decomposition, or the like of the processing liquid constituent components. For example, in the temperature adjustment described above, the concentration of a predetermined component in the processing liquid may increase due to the evaporation of moisture in the processing liquid, as illustrated in FIG. Further, for example, if the processing liquid is continuously reused in the processing of the substrate W, the concentration of the predetermined component in the processing liquid decreases due to evaporation, decomposition, etc. of the predetermined component in the processing liquid as illustrated in FIG. There are things to do. When the concentration of the predetermined component in the processing liquid changes, the concentration of the predetermined component in the processing liquid stored in the tank 12 may deviate from a concentration range suitable for processing the substrate W. Therefore, when the concentration of the predetermined component in the processing liquid measured by the densitometer 16 deviates from a concentration range suitable for processing the substrate W, concentration control is executed.

<Density control>
In the substrate processing apparatus 1, a chemical solution is supplied from the chemical solution supply source 18 to the tank 12 as the processing proceeds. The timing and amount at which the chemical solution supply source 18 supplies the chemical solution may be determined in advance so as to suppress changes in the concentration of the processing solution based on experiments or the like. The chemical solution supply source 18 supplies the chemical solution to the tank 12 when, for example, a predetermined number of substrates are processed or when the accumulated execution time of the processing reaches a predetermined time.

  When the concentration of the predetermined component in the processing liquid measured by the densitometer 16 deviates from the concentration range suitable for processing the substrate W, pure water is supplied from the pure water supply source 17 to the tank 12 or the chemical liquid supply source 18. Then, concentration control for supplying a chemical solution to the tank 12 is executed. In the concentration control, for example, when the concentration of the predetermined component in the processing liquid is increased, the concentration of the predetermined component in the processing liquid is decreased by supplying pure water from the pure water supply source 17. Further, for example, as illustrated in FIG. 6 above, since the concentration of the predetermined component in the processing liquid decreases when the processing liquid is continuously reused, the processing liquid is supplied by supplying the chemical liquid from the chemical liquid supply source 18. A decrease in the concentration of the predetermined component therein is suppressed. When the concentration of the predetermined component in the processing liquid indicated by the densitometer 16 is lower than the lower limit of the concentration range suitable for processing the substrate W, the on-off valve 31d is opened and the on-off valve 31c is closed, so that the pipe waste liquid pipe 27 is opened. Then, a predetermined amount (for example, 3 L) of the processing liquid having a reduced concentration of the predetermined component is drained. By supplying the same amount of chemical liquid as the drained processing liquid from the chemical liquid supply source 18 to the tank 12, the concentration of the predetermined component in the processing liquid stored in the tank 12 is increased.

  As described above, in this embodiment, the initial concentration of the processing liquid stored in the tank 12 is set lower than the concentration supplied by the chemical liquid supply source 18. Therefore, compared with the case where the density | concentration of the processing liquid stored in the tank 12 and the density | concentration of the chemical liquid supplied from the chemical supply source 18 are equal, the processing liquid stored in the tank 12 by supply of a smaller amount of chemical liquid. The concentration of can be increased. That is, according to this embodiment, the amount of the chemical used for concentration control can be reduced.

<Level replenishment>
In the concentration control described above, the chemical liquid is supplied to the tank 12 as the processing proceeds, but the processing liquid stored in the tank 12 may still decrease. When the amount of the processing liquid stored in the tank 12 has decreased to an amount indicating the start of replenishment, level replenishment is performed. In level replenishment, a chemical solution is supplied from the chemical solution supply source 18 to the tank 12, and pure water is supplied from the pure water supply source 17 to the tank 12. The flow rate of the chemical solution supplied from the chemical solution supply source 18 and the flow rate of pure water supplied from the pure water supply source 17 are controlled by the adjustment valves 32b and 32a so that the concentration of the chemical solution becomes the initial concentration. The level replenishment is continued until the amount of the processing liquid stored in the tank 12 indicates a fixed amount that is the amount normally stored in the tank 12.

<Replenishment amount>
By the way, as described above, the processing liquid used for processing in the processing chamber 11 is recovered in the tank 12 via the recovery pipe 23. Since the distance between the processing chamber 11 and the tank 12 varies depending on the installation location of the substrate processing apparatus 1, the time until the processing liquid is collected in the tank 12 after being used in the processing chamber 11 is determined in advance. It is not possible. Further, the substrate processing apparatus 1 can include a plurality of processing chambers 11 as shown in FIG. 4, and the amount of processing liquid recovered in the tank 12 increases as the number of the processing chambers 11 increases. Even when the processing liquid is collected from the processing chamber 11 to the tank 12 after the processing liquid or chemical solution is replenished to the fixed amount in the tank 12 in the above concentration control or level replenishment, the processing liquid does not overflow from the tank 12. Thus, the tank 12 is designed with a sufficient capacity. If the capacity of the tank 12 is designed with a margin, the manufacturing cost of the tank 12 increases, and a large installation space is required due to the installation of the substrate processing apparatus 1.

Therefore, in consideration of the amount of the processing liquid recovered from the processing chamber 11, the amount of chemical liquid or pure water to be replenished in concentration control or level replenishment may be determined. That is, replenishment is performed so that the amount of the treatment liquid in the tank 12 is quantitatively determined by the amount of the chemical liquid or pure water replenished in the tank 12 in the concentration control or level replenishment and the amount of the treatment liquid recovered from the treatment chamber 11. It is only necessary to control the amount of the chemical solution and pure water.

The amount of the processing liquid to be recovered can be determined based on, for example, the amount of the processing liquid discharged in the processing in the processing chamber 11 and the recovery rate. The recovery rate is a ratio indicating the amount of the processing liquid recovered in the tank 12 out of the amount of the processing liquid discharged in the processing in the processing chamber 11, and can be determined by the following equation (1), for example.

  In Expression (1), “amount of processing liquid discharged from the processing chamber 11” is the total amount of processing liquid discharged from the plurality of processing chambers 11 when there are a plurality of processing chambers 11 connected to the tank 12. is there. In the formula (1), the range of the recovery rate is in the range of 0 to 1. For example, the recovery rate is 1 when all the processing liquid discharged from the processing chamber 11 is recovered in the tank 12.

The amount of the processing liquid discharged in the processing chamber 11 can be acquired from a recipe that defines the processing content of the substrate W, for example. For example, the recipe is stored in the storage unit 57, and the control unit 55 may read the recipe from the storage unit 57 and acquire the amount of the processing liquid to be discharged. Further, for example, as illustrated in FIG. 3, an integrated flow meter 112a capable of measuring the integration of the flow rate of the processing liquid discharged to the discharge port 112 of the processing chamber 11 is provided, and the discharge port 112 is provided by the integrated flow meter 112a. It can also be obtained by measuring the amount of the processing liquid to be discharged. When the substrate processing apparatus 1 includes a plurality of processing chambers 11, the total value of the measurement results obtained by the integrated flow meter 112 a included in each processing chamber 11 may be used as the amount of the processing liquid to be discharged. The amount of the processing liquid collected in the tank 12 can be acquired from the liquid level sensor 121 included in the tank 12. Further, the amount of the processing liquid recovered in the tank 12 can also be obtained by measuring with an integrated flow meter 23a provided in the recovery pipe 23 as illustrated in FIG. By confirming the collection rate in advance by a test or the like and storing the confirmed collection rate in the storage unit 57, the integrated flow meter 23a can be omitted from the substrate processing apparatus 1 sold as a product. The supply amount of the chemical solution and pure water to be replenished to the tank 12 can be determined by the following equation (2), for example.

  In Expression (2), the “current liquid amount” is the amount of the processing liquid stored in the tank 12 and can be detected by, for example, the liquid level sensor 121 provided in the tank 12. “Discharge amount” is the amount of the processing liquid discharged from the processing chamber 11, and when there are a plurality of processing chambers 11, is the total of the processing liquid discharged from the plurality of processing chambers 11. That is, the amount of processing liquid collected in the tank 12 is determined by “(discharge amount) × (recovery rate)”. For example, when the fixed amount of the tank 12 is 30 L, the current liquid amount of the tank 12 is 20 L, the amount of the processing liquid discharged from the processing chamber 11 is 10 L, and the recovery rate is 0.9, the chemical solution and pure liquid supplied to the tank 12 The total amount of water is determined to be 1 L by equation (2). For example, when the chemical solution is supplied in the concentration control, the supply amount of the chemical solution is 1 L, and there is no supply of pure water. For example, when pure water is supplied in concentration control, the supply amount of pure water is 1 L, and no chemical solution is supplied. Further, in the level replenishment, the supply amounts of the chemical solution and pure water may be determined based on the concentration of the predetermined component in the processing solution and the total amount determined by the equation (2). The supply amounts of the chemical solution and pure water to be replenished to the tank 12 may be determined by a method other than the equation (2). Further, the total amount of chemical solution and pure water supplied to the tank 12 may further take into account the amount of the processing solution evaporated from the tank 12.

  In the embodiment, the processing liquid used for processing in the processing chamber 11 is recovered in the tank 12 by the recovery pipe 23, but a substrate processing apparatus that does not recover the processing liquid discharged from the processing chamber 11 in the tank 12 is also considered. It is done. The amount of replenishment to the tank when the discharged processing liquid is not recovered may be determined by setting the recovery rate to 0 in equation (2), or may be the same as the discharge amount discharged by the processing chamber 11.

  In the concentration control, as described above, it may be performed when the amount of the processing liquid stored in the tank 12 falls below the fixed amount, but may be performed every time the processing chamber 11 discharges the processing liquid, It may be performed every predetermined period, or may be performed when the amount of the processing liquid discharged from the processing chamber 11 reaches a predetermined amount. For example, when it is performed every predetermined period, the replenishment amount may be determined based on the total discharge amount in the predetermined period. Further, for example, when the processing is performed when the amount of the processing liquid discharged from the processing chamber 11 reaches a predetermined amount, the predetermined amount may be used as the replenishment amount.

<Effects of Embodiment>
In the embodiment, the tank 12 stores a treatment liquid obtained by diluting the chemical liquid supplied from the chemical liquid supply source 18 with pure water supplied from the pure water supply source 17. By using the diluted processing liquid, the concentration decrease due to the reuse of the processing liquid becomes more gradual than when the chemical liquid is used as the processing liquid as it is. Further, since the concentration of the predetermined component in the processing liquid is low, the concentration of the processing liquid stored in the tank 12 can be increased by supplying a small amount of chemical liquid. Since the decrease in the concentration is gradual and the concentration can be increased by supplying a small amount of chemical solution, according to the embodiment, the amount of the processing solution used in the concentration control can be reduced.

  In the embodiment, the densitometer 16 is provided in the circulation pipe 22. As described above, the measurement accuracy of the densitometer 16 decreases when bubbles are generated in the treatment liquid that is the target of concentration measurement. Bubbles are likely to occur in places where there is no flow of processing liquid or where the processing liquid and gas are in contact. Since the treatment liquid pumped by the pump 14 flows in the circulation pipe 22 and the treatment liquid and the gas do not come into contact with each other, it is suitable for the installation of the concentration meter and suppresses the decrease in the measurement accuracy of the concentration meter. Is done.

  In the embodiment, the circulation pipe 22 is connected to a pipe waste liquid pipe 27 for discharging the treatment liquid flowing in the circulation pipe 22, and when the concentration indicated by the densitometer 16 falls below a concentration range suitable for treatment, A predetermined amount of processing liquid is discharged from the pipe waste liquid pipe 27, and a chemical liquid supply source 18 supplies a predetermined amount of chemical liquid to the tank 12. Since the chemical solution is replenished after the processing solution having a reduced concentration is discharged, the concentration of the processing solution can be easily recovered.

  In the embodiment, the pure water supply source 17 supplies pure water to the tank 12 when the concentration indicated by the densitometer 16 exceeds the concentration range suitable for processing. By supplying pure water, the concentration of the treatment liquid in which the concentration of the predetermined component becomes too high can be lowered.

  In the embodiment, the inner diameter of the circulation pipe 22 is formed smaller than the inner diameter of the supply pipe 21. Since the inner diameter of the circulation pipe 22 is smaller than the inner diameter of the supply pipe 21, the flow rate of the processing liquid flowing in the circulation pipe 22 is smaller than the flow volume of the processing liquid flowing in the supply pipe 21. Therefore, it is possible to reduce the amount of the processing liquid flowing through the circulation pipe 22 for concentration measurement. In addition, since the pipe waste liquid pipe 27 is provided in the circulation pipe 22 where the flow rate of the processing liquid is small, the amount of the processing liquid to be drained can be easily controlled.

In the embodiment, the temperature of the processing liquid is adjusted to a temperature higher than a temperature suitable when the chemical liquid supplied from the chemical liquid supply source 18 is used as it is for the processing. The processing efficiency for the substrate W depends on the concentration of the predetermined component in the processing liquid and the temperature of the processing liquid. By adjusting the temperature of the treatment liquid to a higher temperature than when the chemical liquid is used for the treatment as it is, a reduction in treatment efficiency due to the use of the treatment liquid having a predetermined component concentration lower than that of the chemical liquid is suppressed.

  In the embodiment, the amounts of the chemical liquid and pure water that are replenished to the tank 12 by the chemical liquid supply source 18 and the pure water supply source 17 are determined in consideration of the amount of the processing liquid recovered from the processing chamber 11. Therefore, even if the processing liquid used for processing in the processing chamber 11 is collected in the tank 12 after the chemical liquid supply source 18 or the pure water supply source 17 supplies the chemical liquid or pure water to the tank 12, it is stored in the tank 12. It is possible to determine the amount of the treatment liquid to be quantified. Therefore, since the amount of the processing liquid stored in the tank 12 in a state where the processing liquid is collected in the tank 12 is fixed, it is not necessary to manufacture the tank 12 in a large size, and the tank 12 can be downsized. .

<Example>
A more specific configuration of the substrate processing apparatus 1 described in the embodiment will be described. FIG. 7 is a diagram illustrating an example of the configuration of the substrate processing apparatus 1a according to the embodiment, and more specifically illustrates the configuration illustrated in FIG. In the substrate processing apparatus 1a, the same components as those of the substrate processing apparatus 1 are denoted by the same reference numerals, and the description thereof is omitted. Hereinafter, a substrate processing apparatus 1a according to an embodiment will be described with reference to the drawings.

  The substrate processing apparatus 1a includes two tanks 12 (a first tank 12a and a second tank 12b). The first tank 12a is used for supplying the processing liquid to the processing chamber 11, and the second tank 12b is used for preparing the processing liquid and supplying the prepared processing liquid to the first tank 12a. In the second tank 12b, a treatment liquid having an initial concentration is produced based on the chemical liquid supplied from the chemical liquid supply source 18 and the pure water supplied from the pure water supply source 17a. The supply pipe 21a is a pipe that serves as a flow path for the processing liquid from the second tank 12b to the first tank 12a. A plurality of heaters 13a, 13b, 13c, and 13d are arranged along the supply pipe 21a in the supply pipe 21a. The The temperature at which the heaters 13a and 13b heat the treatment liquid is set higher than the heaters 13c and 13d, for example. In the supply pipe 21a, a thermometer 15a is interposed between the heater 13b and the heater 13c arranged next to the heater 13b, and a thermometer 15b is provided on the second tank 12b side of the heater 13d. The temperature of the processing liquid flowing in the supply pipe 21a is measured by the thermometers 15a and 15b. The temperature of the processing liquid heated by the heaters 13a and 13b is measured by the thermometer 15a. The supply pipe 21a is further provided with a pump 14a, and the processing liquid stored in the second tank 12b is pumped to the supply pipe 21a by the pump 14a. The supply pipe 21a is provided with an on-off valve 31e1 on the first tank 12a side of the heaters 13a, 13b, 13c, 13d and the pump 14a. The controller 55 controls the temperatures of the heaters 13c and 13d based on the measurement result of the thermometer 15a. In the supply pipe 21a, a circulation pipe 22a extending from the pipe path 21p1 to the second tank 12b is connected to the pipe path 21p1 closer to the second tank 12b than the on-off valve 31e1 and closer to the first tank 12a than the pump 14a. Is done. An opening / closing valve 31c1 is provided in the circulation pipe 22a. When the temperature of the processing liquid is adjusted in the second tank 12b, the on-off valve 31e1 is closed to close the flow path to the first tank 12a, and the on-off valve 31c1 is opened. The flow path to the second tank 12b is opened. The processing liquid stored in the second tank 12b is pumped to the supply pipe 21a by the pump 14a, and the pumped processing liquid is heated by the heaters 13a, 13b, 13c, and 13d, and the second tank is passed through the circulation pipe 22a. Returned to 12b. The heaters 13a, 13b, 13c, and 13d are examples of “second heating means”. Each of the heaters 13a, 13b, 13c, and 13d is an example of a “heating unit”. The first tank 12a is an example of a “first storage tank”. The second tank 12b is an example of a “second storage tank”. The supply pipe 21a is an example of a “second supply pipe”. The circulation pipe 22a is an example of a “second circulation pipe”. The middle 21p1 of the pipeline is an example of “second half of the pipeline”. The heater 13b is an example of “one heating unit”.

  The first tank 12a is supplied with the treatment liquid prepared in the second tank 12b and adjusted in temperature via the supply pipe 21a. Each of the supply pipes 21b and 21b is a pipe that becomes a flow path of the processing liquid from the first tank 12a to each of the processing chambers 11 and 11, and each of the supply pipes 21b and 21b includes a heater 13e and 13e and a pump 14b. Provided. A circulation pipe 22b extending from the pipe passages 21p2 and 21p2 to the first tank 12a is connected to the pipe pipes 21p2 and 21p2 of the supply pipes 21b and 21b. The circulation pipe 22b is provided with an on-off valve 31g, an integrated flow meter 33c, an adjustment valve 32c, a concentration meter 16, and an on-off valve 31c2 in order from the middle 21p2 to the first tank 12a. The concentration meter 16 may be provided in the circulation pipe 22a, but the concentration of the processing liquid at a position closer to the processing chamber 11 can be measured by providing the concentration meter 16 in the circulation pipe 22b. The supply pipes 21b and 21b further include return pipes 21b1 extending from the pipe paths 21p3 and 21p3 to the first tank 12a in the pipe paths 21p3 and 21p3 provided on the processing chamber 11 side of the pipe path 21p2. 21b1 is connected. The return pipes 21b1 and 21b1 are pipes having an inner diameter larger than that of the circulation pipe 22b (that is, the passage cross-sectional area is larger). For example, the return pipes 21b1 and 21b1 have an inner diameter of 25 mm and the circulation pipe 22b has an inner diameter of 6 mm. is there. The return pipe 21b1 is an example of “return pipe”. The heater 13e is an example of a “first heating unit”. The supply pipe 21b is an example of a “first supply pipe”. The circulation pipe 22b is an example of a “first circulation pipe”. The middle 21p2 of the pipe line is an example of “middle of the first pipe line”.

  Each of the first tank 12a and the second tank 12b is provided with the liquid level sensor 121 described above. Since the second tank 12b is a supply source of the processing liquid to the first tank 12a, a tank having a larger capacity than the first tank 12a is used for the second tank 12b. Therefore, the amount of the processing liquid whose liquid level is “determined” in the second tank 12b is set to be larger than the amount of the processing liquid whose liquid level is “determined” in the first tank 12a. The For example, in the second tank 12b, the amount of the processing liquid whose liquid level is “determined” is “60L”, and in the first tank 12a, the amount of the processing liquid whose liquid level is “determined” is “30L”. Is.

  The chemical liquid supply source 18 is connected to chemical liquid supply pipes 26a and 26b that serve as a flow path for the chemical liquid to the second tank 12b. The chemical solution supply pipe 26a is provided with an on-off valve 31b1, an adjustment valve 32b1, and an instantaneous flow meter 33b1. When the on-off valve 31b1 is opened, a flow path through the chemical solution supply pipe 26a from the chemical solution supply source 18 to the second tank 12b is secured, and when the on-off valve 31b1 is closed, the chemical solution supply source 18 connects the second tank. The flow path through the chemical solution supply pipe 26a to 12b is closed. The flow rate of the chemical liquid flowing through the chemical liquid supply pipe 26a is controlled by the adjustment valve 32b1. The instantaneous flow meter 33b1 measures the flow rate per unit time of the chemical liquid flowing through the chemical liquid supply pipe 26a. The chemical solution supply pipe 26b is provided with an on-off valve 31b2, an adjustment valve 32b2, and an instantaneous flow meter 33b2. A pure water supply pipe 25a is connected in the middle 26p of the chemical liquid supply pipe 26b. When the on-off valve 31b2 is opened, a flow path is secured from the chemical liquid supply source 18 to the second tank 12b via the chemical liquid supply pipe 26b. When the on-off valve 31b2 is closed, the chemical liquid supply source 18 connects the second tank. The flow path via the chemical solution supply pipe 26b to 12b is closed. The flow rate of the chemical liquid flowing through the chemical liquid supply pipe 26b is controlled by the adjustment valve 32b2. The instantaneous flow meter 33b2 measures the flow rate per unit time of the chemical liquid flowing through the chemical liquid supply pipe 26b.

  The substrate processing apparatus 1a includes a pure water supply source 17a and a pure water spike tank 17b (denoted as DIW SPK Tank in the drawing) as pure water supply sources. The pure water supply source 17a is connected to a pure water supply pipe 25a that serves as a pure water flow path to the second tank 12b. The pure water supply pipe 25a is provided with an on-off valve 31a, a regulating valve 32a, and an instantaneous flow meter 33a. The pure water supply source 17a is the same as the pure water supply source 17 according to the embodiment except that the pure water supply destination is the second tank 12b.

The pure water spike tank 17b includes a pure water supply pipe 2 that provides a flow path of pure water to the second tank 12b.
5b is connected. The pure water supply pipe 25b is provided with a pump 14d. By being pumped by the pump 14d, a predetermined amount (for example, 100 ml) of pure water is supplied from the pure water spike tank 17b to the second tank 12b.

  By the way, the temperature of the processing liquid used for processing the substrate W and recovered by the recovery tube 23 is lower than the temperature suitable for processing the substrate W. If such a processing liquid is returned to the first tank 12a, the temperature of the processing liquid stored in the first tank 12a is lowered. Therefore, in the substrate processing apparatus 1a, the recovery pipe 23 for returning the processing liquid used for processing the substrate W to the tank 12 is provided so as to extend from the processing chamber 11 to the second tank 12b. That is, the processing liquid used for processing the substrate W in the processing chamber 11 is returned to the second tank 12 b through the recovery pipe 23. The processing liquid that is pumped from the second tank 12b to the first tank 12a is heated by the heaters 13a, 13b, 13c, and 13d. Therefore, a decrease in the temperature of the processing liquid stored in the first tank 12a is suppressed.

  The processing flow of the substrate W in the substrate processing apparatus 1a having the above configuration will be described below with reference to FIGS. In FIG. 8 to FIG. 19, piping through which the processing liquid flows is indicated by a thick line.

<Preparation of treatment liquid>
8 to 13 are diagrams showing an example of the piping operation of the substrate processing apparatus 1a during the preparation of the processing liquid. Hereinafter, an example of the piping operation of the substrate processing apparatus 1a during the preparation of the processing liquid will be described with reference to FIGS.

  FIG. 8 is a first diagram illustrating an example of the piping operation of the substrate processing apparatus 1a during the preparation of the processing liquid. Since this is the start of the preparation of the treatment liquid, both the first tank 12a and the second tank 12b are empty. When the preparation of the treatment liquid is started, the chemical liquid supply source 18 sends the chemical liquid to the chemical liquid supply pipe 26b in a state where the on-off valve 31b2 is opened and the on-off valve 31b1 is closed. The flow rate of the chemical liquid flowing through the chemical liquid supply pipe 26b is controlled by the adjustment valve 32b2. The pure water supply source 17a sends pure water to the pure water supply pipe 25a with the on-off valve 31a being opened. The flow rate of pure water flowing through the pure water supply pipe 25a is controlled by the regulating valve 32a. The chemical liquid supply pipe 26b and the pure water supply pipe 25a are connected in the middle of the pipe line 26p, and the flow rate of the chemical liquid supplied from the chemical liquid supply source 18 and the flow rate of pure water supplied from the pure water supply source 17a are respectively adjusted valves. By being controlled by 32b2 and the adjustment valve 32a, the processing liquid adjusted to the initial concentration is supplied to the second tank 12b.

  FIG. 9 is a second diagram illustrating an example of the piping operation of the substrate processing apparatus 1a during the preparation of the processing liquid. When the liquid level of the processing liquid stored in the second tank 12b exceeds the lower limit, temperature adjustment of the processing liquid is started. In the temperature adjustment, the on-off valve 31c1 is opened and the on-off valve 31e1 is closed. Then, the processing liquid in the second tank 12b is pumped to the supply pipe 21a by the pump 14a, and the processing liquid pumped to the supply pipe 21a is heated by the heaters 13a and 13b. The temperature of the processing liquid heated by the heaters 13a and 13b is measured by a thermometer 15a. The control unit 55 acquires the temperature measured by the thermometer 15a from the thermometer 15a, and controls the temperatures of the heaters 13c and 13d based on the acquired temperature. The processing liquid heated by the heaters 13c and 13d is returned to the second tank 12b through the circulation pipe 22a after its temperature is measured by the thermometer 15b. Such circulation is repeated until the temperature of the processing liquid measured by the thermometer 15b falls within a temperature range suitable for processing the substrate W, and the temperature adjustment of the processing liquid is executed. Further, while the temperature adjustment is being performed, the preparation of the processing liquid described with reference to FIG. 8 is continued.

FIG. 10 is a third diagram illustrating an example of the piping operation of the substrate processing apparatus 1a during the preparation of the processing liquid. The temperature of the processing liquid stored in the second tank 12b is adjusted to a temperature range suitable for processing the substrate W, and the liquid level of the processing liquid stored in the second tank 12b is “quantitative”. When reaching, the supply of the processing liquid from the second tank 12b to the first tank 12a is started. First, the on-off valve 31c1 is closed and the on-off valve 31e1 is opened, so that a flow path for the processing liquid from the second tank 12b to the first tank 12a is secured. Thereafter, the processing liquid stored in the second tank 12b is pumped to the first tank 12a via the supply pipe 21a by the pump 14a. The heaters 13a, 13b, 13c, and 13d provided in the supply pipe 21a are controlled so that the processing liquid fed to the first tank 12a does not deviate from a temperature range suitable for processing the substrate W.

  FIG. 11 is a fourth diagram illustrating an example of the piping operation of the substrate processing apparatus 1a during the preparation of the processing liquid. The temperature of the processing liquid stored in the first tank 12a may decrease until the liquid level of the processing liquid reaches a fixed amount in the first tank 12a. Therefore, in the substrate processing apparatus 1a, when the liquid level of the processing liquid stored in the first tank 12a exceeds the “lower limit”, the temperature of the processing liquid is adjusted in the first tank 12a. In this temperature adjustment, the processing liquid stored in the first tank 12a is pumped to the supply pipe 21b by the pump 14b. The processing liquid pressure-fed to the supply pipe 21b is heated by the heater 13e. The treatment liquid heated by the heater 13e is divided into a flow flowing in the supply pipe 21b as it is toward the middle 21p3 in the supply pipe 21b and a flow flowing into the circulation pipe 22b in the middle 21p2. The processing liquid flowing toward the middle 21p3 of the pipeline flows into the return pipe 21b1 in the middle 21p3 of the pipeline and is returned to the first tank 12a. Further, the processing liquid flowing into the circulation pipe 22b is returned to the first tank 12a after the concentration meter 16 measures the concentration of the predetermined component in the processing liquid.

  FIG. 12 is a fifth diagram illustrating an example of the piping operation of the substrate processing apparatus 1a during the preparation of the processing liquid. When the liquid level of the processing liquid stored in the first tank 12a reaches a fixed amount due to the supply of the processing liquid from the second tank 12b, the supply of the processing liquid from the second tank 12b to the first tank 12a is stopped. Is done. Specifically, the on-off valve 31e1 is closed to close the flow path of the processing liquid from the second tank 12b to the first tank 12a, and the on-off valve 31c1 is opened to open the second tank from the circulation pipe 22a. A flow path to 12b is secured. In the second tank 12b, the temperature adjustment of the processing liquid and the preparation of the processing liquid described with reference to FIG. 9 are executed. In the first tank 12a, the temperature adjustment of the processing liquid described with reference to FIG. 11 is executed.

  FIG. 13 is a sixth diagram illustrating an example of the piping operation of the substrate processing apparatus 1a during the preparation of the processing liquid. In FIG. 13, the temperature adjustment in the first tank 12 a and the temperature adjustment in the second tank 12 b and the preparation of the treatment liquid described in FIG. The state in which the liquid level height of the stored processing liquid has reached a fixed amount is illustrated while finishing the temperature adjustment. The concentration of the processing liquid stored in the first tank 12a and the second tank 12b is adjusted to the initial concentration, and the initial concentration is, for example, 43%. In the state illustrated in FIG. 13, the amount of the processing liquid stored in the first tank 12a and the second tank 12b has reached a fixed amount, and the temperature and concentration of the processing liquid are both within the range suitable for processing. It has become. Therefore, the state illustrated in FIG. 13 can be said to be a state where preparation for starting the processing of the substrate W is completed.

<When processing is executed>
14 to 19 are diagrams illustrating an example of the piping operation of the substrate processing apparatus 1a that performs processing on the substrate W. FIG. Hereinafter, an example of the piping operation of the substrate processing apparatus 1a that performs processing on the substrate W will be described with reference to FIGS.

FIG. 14 is a first diagram illustrating an example of the piping operation of the substrate processing apparatus 1a that performs processing on the substrate W. In FIG. 14, the processing liquid stored in the first tank 12a is supplied to the processing chamber 11 through the supply pipe 21b. The processing chamber 11 performs processing by discharging the processing liquid supplied from the first tank 12 a to the substrate W from the discharge port 112. The processing liquid used for the processing in the processing chamber 11 is returned to the second tank 12b through the recovery pipe 23. Therefore, when the processing in the processing chamber 11 is continued, the liquid level of the processing liquid stored in the first tank 12a is lowered. Therefore, when the liquid level of the processing liquid stored in the first tank 12a falls below the fixed amount, supply of the processing liquid from the second tank 12b to the first tank 12a is started. Specifically, the on-off valve 31e1 is opened to secure a flow path for the processing liquid from the second tank 12b to the first tank 12a. The pump 14a pumps the processing liquid stored in the second tank 12b to the first tank 12a through the supply pipe 21a. When the liquid level of the processing liquid stored in the second tank 12b is below the lower limit, the supply of the processing liquid from the second tank 12b to the first tank 12a is not executed. Processing in such a case will be described later.

  FIG. 15 is a second diagram illustrating an example of the piping operation of the substrate processing apparatus 1a that performs processing on the substrate W. FIG. 15 shows an example of the density control described above. As described above, when the processing of the substrate W is continued, the concentration of the predetermined component in the processing liquid changes. Accordingly, a predetermined amount of chemical liquid is supplied from the chemical liquid supply source 18 to the second tank 12b according to the number of processed substrates W, and the processing liquid is supplied from the second tank 12b to the first tank 12a. Changes in the concentration of the treatment liquid used are suppressed. For example, 1L of chemical liquid is supplied from the chemical liquid supply source 18 to the second tank 12b every time 25 substrates W are processed. The amount of the chemical liquid supplied from the chemical liquid supply source 18 may be determined in consideration of the amount of the processing liquid recovered from the processing chamber 11, for example. Specifically, the amount of the chemical liquid supplied from the chemical liquid supply source 18 may be determined based on the above-described formula (1) and formula (2).

  FIG. 16 is a third diagram illustrating an example of the piping operation of the substrate processing apparatus 1a that performs processing on the substrate W. FIG. 16 shows an example of the level replenishment described above. Even if chemical liquid is supplied from the chemical liquid supply source 18 to the second tank 12b, if the liquid level of the processing liquid stored in the second tank 12b falls below the start of replenishment, the on-off valve 31b1 is closed and opened / closed. The valve 31b2 is opened to switch the pipe used for supplying the chemical liquid from the chemical liquid supply pipe 26a to the chemical liquid supply pipe 26b. Further, by opening the on-off valve 31a, pure water is supplied from the pure water supply source 17a to the second tank 12b. That is, as described above, the processing liquid adjusted to the initial concentration is supplied to the second tank 12b. The supply of the processing liquid adjusted to the initial concentration is continued until the liquid level of the processing liquid stored in the first tank 12a and the second tank 12b shows a fixed amount. Note that the total amount of the chemical solution supplied from the chemical solution supply source 18 and the pure water supplied from the pure water supply source 17 is determined in consideration of the amount of the processing solution recovered from the processing chamber 11, for example. May be. Specifically, the total amount of the chemical solution supplied by the chemical solution supply source 18 and the pure water supplied by the pure water supply source 17 is determined based on the above formulas (1) and (2). May be.

  FIG. 17 is a fourth diagram illustrating an example of the piping operation of the substrate processing apparatus 1a that performs processing on the substrate W. FIG. 17 shows an example of the density control described above. If the processing of the substrate W is continued, the concentration of the processing liquid may decrease with the passage of time due to evaporation and decomposition of the processing liquid constituent components. If the concentration of the processing liquid stored in the first tank 12a decreases even after the chemical liquid illustrated in FIG. 15 is supplied, the on-off valve 31d is opened to drain the processing liquid by a predetermined amount (for example, 3L). The The amount of the drained processing liquid is managed by the integrated flow meter 33c, for example. While draining, the supply of the processing liquid to the processing chamber 11 is stopped, and the processing of the substrate W by the processing chamber 11 is also stopped. Further, the supply of the processing liquid from the second tank 12b to the first tank 12a is stopped, and the temperature of the processing liquid is adjusted in the second tank 12b.

FIG. 18 is a fifth diagram illustrating an example of the piping operation of the substrate processing apparatus 1a that performs processing on the substrate W. FIG. 18 shows an example of the above density control. As illustrated in FIG.
When the drain of the processing liquid is executed, the amount of the processing liquid stored in the first tank 12a decreases. As a result of the decrease in the amount of the processing liquid, when the liquid level of the processing liquid stored in the first tank 12a falls below the fixed amount, the processing liquid is supplied from the second tank 12b to the first tank 12a. Further, the same amount (for example, 3 L) of the chemical solution as the drained amount is supplied from the chemical solution supply source 18 to the second tank 12b.

  FIG. 19 is a sixth diagram illustrating an example of the piping operation of the substrate processing apparatus 1a that performs processing on the substrate W. FIG. 19 shows an example of the density control described above. If the processing of the substrate W is continued, the moisture in the processing liquid evaporates with time, and the concentration of the predetermined component in the processing liquid may increase. When the concentration of the predetermined component increases, an appropriate amount (for example, 100 ml) of pure water is supplied from the pure water spike tank 17b to the second tank 12b to decrease the concentration of the predetermined component. By this control, a change in the concentration of the predetermined component in the processing liquid is suppressed. Further, since the amount of pure water supplied at one time is defined, the concentration of the predetermined component in the processing liquid does not become lower than the allowable range.

<Effects of Example>
In the embodiment, the second tank 12b stores a treatment liquid obtained by diluting the chemical liquid supplied from the chemical liquid supply source 18 with pure water supplied from the pure water supply source 17a. By using the diluted processing liquid, the concentration decrease due to the reuse of the processing liquid becomes more gradual than when the chemical liquid is used as the processing liquid as it is. Further, since the concentration of the predetermined component in the processing liquid is low, the concentration of the processing liquid stored in the second tank 12b can be increased by supplying a small amount of chemical liquid. Since the decrease in the concentration is gradual and the concentration can be increased by supplying a small amount of the chemical solution, according to the embodiment, the amount of the processing solution used for the concentration control can be reduced.

  In the embodiment, the densitometer 16 is provided in the circulation pipe 22b connected to the first tank 12a. Since the processing liquid supplied to the processing chamber 11 is stored in the first tank 12a, the concentration meter 16 is provided in the circulation pipe 22b, thereby measuring the concentration of the processing liquid supplied to the processing chamber 11 with high accuracy. It is possible.

  In the embodiment, the pipe waste liquid pipe 27 is connected to the circulation pipe 22b. When the concentration indicated by the densitometer 16 falls below the concentration range suitable for processing, a predetermined amount of processing liquid is discharged from the pipe waste liquid pipe 27 and the chemical liquid supply source 18 supplies a predetermined amount of chemical liquid to the second tank 12b. To do. Since the supply destination to which the chemical solution is supplied is not the first tank 12a but the second tank 12b, rapid changes in the concentration and temperature of the processing solution in the first tank 12a are suppressed.

  In the embodiment, the pure water supply source 17a supplies pure water to the second tank 12b when the concentration indicated by the densitometer 16 exceeds the concentration range suitable for processing. Since the supply destination to which pure water is supplied is not the first tank 12a but the second tank 12b, rapid changes in the concentration and temperature of the processing liquid in the first tank 12a are suppressed.

  In the embodiment, the supply pipe 21a that connects the second tank 12b and the first tank 12a is provided with heaters 13a, 13b, 13c, and 13d, and the supply pipe 21b that connects the first tank 12a and the processing chamber 11. Is provided with a heater 13e. The amount of heat that the heaters 13a, 13b, 13c, and 13d give to the treatment liquid is larger than the amount of heat that the heater 13e gives to the treatment liquid. Therefore, in adjusting the temperature in the second tank 12b, the temperature of the processing liquid can be adjusted to a temperature suitable for processing in a shorter time, and when supplying the processing liquid from the first tank 12a to the processing chamber 11, the heater 13e. Thus, the temperature of the treatment liquid is finely adjusted. Therefore, the processing liquid can be adjusted to a temperature suitable for processing in a shorter time, and the temperature of the processing liquid supplied to the processing chamber 11 can be controlled with high accuracy.

In the embodiment, a plurality of heaters 13a, 13b, 13c, 13d provided in the supply pipe 21a.
, The temperature at which the heaters 13a and 13b heat the treatment liquid is set higher than the heaters 13c and 13d. Thermometers 15a and 15b are provided between the heater 13b and the heater 13c and closer to the second tank 12b than the heater 13d, respectively, and the temperature of the processing liquid flowing in the supply pipe 21a is measured. The controller 55 controls the temperatures of the heaters 13c and 13d based on the measurement result of the thermometer 15a. That is, after the temperature of the processing liquid is roughly adjusted by the heaters 13a and 13b, the temperature of the processing liquid is finely adjusted by the heaters 13c and 13d, so that the temperature control accuracy of the processing liquid can be improved.

  In the embodiment, the supply destination of the chemical liquid supply source 18, the pure water supply source 17a, and the pure water spike tank 17b is the second tank 12b. The processing liquid stored in the second tank 12b is supplied to the first tank 12a after the concentration and temperature are adjusted. Therefore, in the first tank 12a, changes in the concentration and temperature of the processing liquid due to the supply from the chemical liquid supply source 18, the pure water supply source 17a, or the pure water spike tank 17b are suppressed.

  The embodiments and examples disclosed above can be combined.

<< Computer-readable recording medium >>
An information processing program that causes a computer or other machine or device (hereinafter, a computer or the like) to realize any of the functions described above can be recorded on a computer-readable recording medium. Then, the function can be provided by causing the computer or the like to read and execute the program of the recording medium.

Here, a computer-readable recording medium refers to a recording medium that stores information such as data and programs by electrical, magnetic, optical, mechanical, or chemical action and can be read from a computer or the like. Say. Among such recording media, those removable from a computer or the like include, for example, a flexible disk, a magneto-optical disk, a compact disc read only memory (CD-ROM), a compact disc-recordable (CD-R), and a compact disc-rewriterable. (CD-RW), Digital Versatile Disc (DVD), Blu-ray Disc (BD), Digital Audio Tape (DAT), 8 mm tape, flash memory, and other memory cards. Moreover, there are a hard disk, a ROM, and the like as a recording medium fixed to a computer or the like.

DESCRIPTION OF SYMBOLS 1, 1a ... Substrate processing apparatus 11 ... Processing chamber 111 ... Table 112 ... Discharge port 113 ... Wall 12 ... Tank 121 ... Liquid level sensor 12a ... 1st tank 12b: second tank 13, 13a, 13b, 13c, 13d, 13e ... heater 15 ... concentration meter 16 ... thermometer 17, 17a ... pure water supply source 17b ... pure water Spike tank 18 ... Chemical solution supply source 21 ... Supply pipe 21b1 ... Return pipe 22 ... Circulation pipe 23 ... Recovery pipe 24 ... Tank waste liquid pipe 25, 25a ... Pure water supply pipe 26, 26a, 26b ... Chemical liquid supply pipe 27 ... Pipe waste liquid pipe 33a, 33b, 33b1, 33b2 ... Instantaneous flow meter 23a, 112a ... Integrated flow meter

Claims (13)

A substrate processing apparatus that performs predetermined processing on a substrate by discharging a processing liquid containing a chemical and pure water onto the substrate,
A chemical solution supply unit for supplying the chemical solution containing a predetermined component;
A pure water supply unit for supplying the pure water;
A storage tank for storing the treatment liquid having a concentration of the predetermined component lower than that of the chemical liquid by including the chemical liquid supplied from the chemical liquid supply section and the pure water supplied from the pure water supply section;
A substrate processing unit that performs predetermined processing on the substrate by discharging the processing liquid onto the substrate;
A supply pipe serving as a flow path for the processing liquid from the storage tank to the substrate processing unit;
A recovery pipe for returning the processing liquid discharged to the substrate in the substrate processing section to the storage tank;
The chemical liquid supply unit suppresses a decrease in the concentration of the processing liquid by supplying the chemical liquid to the storage tank according to the progress of the predetermined processing.
Substrate processing equipment. The chemical solution supply unit supplies the chemical solution to the storage tank every time the substrate processing unit performs the predetermined number of the predetermined processes on the substrate.
The substrate processing apparatus according to claim 1. The chemical solution supply unit supplies the chemical solution to the storage tank when an accumulated execution time of the predetermined processing by the substrate processing unit reaches a predetermined time.
The substrate processing apparatus according to claim 1 or 2. A circulation pipe that becomes a flow path from the middle of the supply pipe to the storage tank;
The circulation pipe is provided with a densitometer that measures the concentration of the predetermined component in the processing liquid flowing in the circulation pipe.
The substrate processing apparatus according to claim 1. The circulation pipe is further provided with a waste liquid pipe for discharging the treatment liquid flowing in the circulation pipe,
When the concentration indicated by the densitometer falls below a concentration range suitable for the predetermined treatment, a predetermined amount of the processing liquid is discharged from the waste liquid pipe, and the chemical liquid supply unit discharges the predetermined amount of the chemical liquid. Supply to the storage tank,
The substrate processing apparatus according to claim 4. The pure water supply unit further executes a process of supplying the pure water to the storage tank when the concentration indicated by the densitometer exceeds a concentration range suitable for the predetermined process.
The substrate processing apparatus according to claim 5. While being connected to the substrate processing unit side than the middle of the pipeline of the supply pipe, further comprising a return pipe for returning the processing liquid to the storage tank,
The inside diameter of the circulation pipe is formed narrower than the inside diameter of the return pipe,
The substrate processing apparatus according to claim 4. In the supply pipe, a heating means for heating the processing liquid flowing in the supply pipe is provided closer to the storage tank than in the middle of the pipe line,
The heating means heats the treatment liquid to a temperature higher than when the chemical liquid is used for the predetermined treatment.
The substrate processing apparatus according to claim 4. The storage tank includes a first storage tank and a second storage tank,
The supply pipe is a first supply pipe serving as a flow path for the processing liquid between the first storage tank and the substrate processing unit, and the processing between the second storage tank and the first storage tank. A second supply pipe serving as a liquid flow path,
The circulation pipe includes a first circulation pipe serving as a flow path from the middle of the first supply pipe to the first storage tank, and the second storage from the middle of the second pipeline of the second supply pipe. A second circulation pipe serving as a flow path to the tank,
The heating means is provided closer to the first storage tank than the middle of the first pipeline in the first supply pipe, and the first heating means for heating the processing liquid flowing in the first supply pipe; A second heating unit that is provided closer to the second storage tank than the middle of the second pipe in the second supply pipe, and that heats the treatment liquid flowing in the second supply pipe;
The second heating means heats the treatment liquid at a temperature higher than that of the first heating means,
The substrate processing apparatus according to claim 8. The second heating means includes a plurality of heating units arranged along the second supply pipe,
The temperature of the processing liquid flowing in the second supply pipe is interposed between any one of the plurality of heating units and a heating unit disposed next to the one heating unit. A thermometer to measure,
Based on the measurement result of the thermometer, the temperature of the heating unit arranged on the first storage tank side than the thermometer is controlled,
The substrate processing apparatus according to claim 9. The chemical solution supply unit supplies the chemical solution to the second storage tank,
The pure water supply unit supplies the pure water to the second storage tank;
The substrate processing apparatus according to claim 9 or 10. The predetermined component includes hydrofluoric acid,
The substrate processing apparatus according to claim 1. A substrate processing method for performing predetermined processing on a substrate by discharging a processing liquid containing a chemical and pure water onto the substrate,
By storing a chemical liquid containing a predetermined component and pure water, the processing liquid having a lower concentration of the predetermined component than the chemical liquid is stored in a storage tank,
By discharging the processing liquid supplied from the storage tank to the substrate, a predetermined process is performed on the substrate,
Returning the processing liquid discharged to the substrate to the storage tank;
By supplying the chemical solution to the storage tank according to the progress of the predetermined treatment, it is possible to suppress a decrease in the concentration of the treatment solution,
Substrate processing method.

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