Processing liquid supplying apparatus, substrate processing apparatus, and processing liquid supplying method

Abstract

To provide a process liquid supply device, a substrate treatment device and a process liquid supply method with which it is possible to suppress costs and prevent variation in the measured concentration value of a process liquid in each tank, and adjust the concentration of the process liquid to be supplied.SOLUTION: A process liquid supply device 1, which is connected to a treatment device 100 for substrates W in a substrate treatment device SS, comprises: a plurality of tanks T1-T4; a supply path S that supplies a process liquid L to the treatment device by sequentially going through the plurality of tanks; heating units H1-H4 that heat the process liquid; a dilution unit I that dilutes the process liquid; a new liquid supply unit J that supplies a new liquid; a common flow channel C in which the process liquid from the plurality of tanks circulates in common; a switch unit SW that switches between the tanks of the process liquid for the process liquid flowing in the common flow channel; a densitometer D which is provided in the common flow channel; and a control device E that controls at least one of the heating unit, the dilution unit and the new liquid supply unit so that the concentration of the process liquid in each tank is measured by the densitometer, ensuring that the concentration equals a prescribed target value.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a processing liquid supplying apparatus, a substrate processing apparatus, and a processing liquid supplying method. [Background technology]

[0002] 2. Description of the Related Art In manufacturing processes for producing semiconductors and flat panel displays, processing equipment is used to supply an etching solution to a film provided on the surface of a substrate, such as a semiconductor wafer or a glass substrate, thereby etching the film to form a desired circuit pattern.

[0003] For example, single-wafer processing apparatuses, which supply processing liquid to a rotating substrate and process each substrate one by one, are able to achieve a higher level of processing uniformity for each substrate than batch processing apparatuses, which process multiple substrates all at once by immersing them in processing liquid. As a result, these types of processing apparatuses have come to be used more frequently in recent years in conjunction with the miniaturization of circuit patterns.

[0004] but, Single-wafer In this processing equipment, processing is performed one wafer at a time, so unless the processing time for each wafer is shortened, productivity will be inferior to that of the batch type. Therefore, in order to increase productivity while maintaining high processing performance, processing must be performed in a short time with little variation. In the batch type, fluctuations in parameters such as the temperature and concentration of the processing liquid can be adjusted over time in the processing tank before processing and then immersed. However, in the single wafer type, the processing liquid supplied to the substrate must be supplied so that parameters that affect the process performance are always constant.

[0005] In addition, batch type, Single-waferIn both of these processing equipment, from the viewpoint of reducing processing costs, it is essential to recover and reuse the liquid used in processing. Even when recycling in this way, in the batch type, parameters can be checked and adjusted during the long processing time during which the substrate is immersed in the processing tank. However, in the case of the single-wafer type, each substrate is processed in a short period of time. Therefore, fluctuations in the parameters of the processing liquid supplied to the substrate are reflected in the product as variations in the processing performance for processing the substrate. For this reason, it is necessary to always use a processing liquid, including the recovered processing liquid, that is adjusted to the optimal concentration and temperature. Processing solution However, the processing liquid must be continuously supplied to the substrate. In other words, in the single-wafer processing, it is necessary to always keep fluctuations in the concentration and temperature of the processing liquid within a very small range.

[0006] Here, it is the recovered liquid that has a large effect on the fluctuation of the temperature of the processing liquid. In other words, since the processing liquid used in the processing drops in temperature, the used processing liquid must be recovered and heated again, but ingenuity is required to maintain the temperature of this recovered liquid at a relatively high temperature and supply it. For example, the amount of recovered liquid varies depending on the timing of processing, so a predetermined amount of recovered liquid is not recovered in a predetermined period of time. In particular, when processing is performed in multiple processing chambers at the same time, the timing of processing substrates in each processing chamber varies, so the amount of recovered liquid also varies greatly with time. In a configuration in which the recovered liquid is collected in a tank and heated for reuse, a large temperature fluctuation occurs depending on the inflow amount of recovered liquid.

[0007] On the other hand, the concentration of the processing liquid needs to be adjusted by heating it over a long period of time or by adding a diluent such as pure water, and this is done in a supply tank. The recovered liquid is adjusted in concentration in the supply tank to become the processing liquid, so the range of concentration adjustment is relatively small. However, when the cost of the processing liquid is high, in order to increase the recovery rate of the processing liquid and reduce the processing cost, even processing liquid that contains a certain amount of liquid such as a rinse liquid that does not interfere with reuse will be recovered and reused. For this reason, it is important to restore the concentration of the processing liquid used in processing.

[0008] Even in cases where the concentration of the recovery liquid is always low, in a recovery tank where no processing has been performed for a long time and no new recovery liquid is being received, heating is always performed to maintain the liquid in the recovery tank at a high temperature, so the concentration of the recovery liquid increases over time. Since no substrate processing is performed while no recovery liquid is being received, there is no decrease in the amount of liquid in the supply tank that sends the liquid to the recovery tank, and the concentration in the recovery tank increases further. Therefore, concentration control is important even in the recovery tank.

[0009] As a method for suppressing temperature and concentration fluctuations during recovery and reuse of such single-wafer processing liquid, a substrate processing apparatus as shown in Patent Document 1 has been proposed. This substrate processing apparatus has a supply tank for supplying processing liquid to a processing unit, a recovery tank for recovering the processed processing liquid, and an adjustment tank for making the recovered liquid reusable. After recovery of the processing liquid, the recovery tank adjusts the temperature and concentration of the processing liquid as an adjustment tank, and the tank that was used as the adjustment tank is switched to be used as the recovery tank. This makes it possible to continuously send the recovered processing liquid and the processing liquid whose temperature and concentration have been adjusted to the supply tank. In addition, the concentration of the processing liquid can be adjusted efficiently by sequentially switching between two tanks that contain the recovered liquid, without leaving each tank idle. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] Patent No. 6324775 Summary of the Invention [Problem to be solved by the invention]

[0011] In the above technology, two recovery tanks are used for one supply tank, and can be switched between recovery and concentration adjustment, so that control can be continued from when the temperature and concentration are converged to within the target range until the supply of the treatment liquid to the supply tank is completed. In such an apparatus, a concentration meter is provided in each adjustment tank, and when adjusting the treatment liquid in each tank, the concentration of the treatment liquid is adjusted using each concentration meter.

[0012] However, having a concentration meter for each tank means that there are individual differences between the concentration meters, which means that the measured values ​​displayed by each concentration meter will differ. In other words, there will be variation in the measured values ​​measured by each concentration meter. The variation between each concentration meter causes a deviation in the control performed against a common target value, so even if the measured values ​​match, they may not actually converge to the target value. To eliminate such variation, it is necessary to adjust each concentration meter, but this adjustment takes time and reduces productivity. Furthermore, installing a concentration meter in each tank increases the number of equipment configurations, which increases costs.

[0013] An object of an embodiment of the present invention is to provide a processing liquid supply device, a substrate processing apparatus, and a processing liquid supply method that can adjust the concentration of the processing liquid supplied while reducing costs and preventing variation in the measured values ​​of the processing liquid concentration in each tank. [Means for solving the problem]

[0014] An embodiment of the present invention is a processing liquid supply device that supplies a processing device that processes a substrate with the processing liquid, the processing liquid supply device comprising: a plurality of tanks that store the processing liquid; a supply path that connects the plurality of tanks so that the processing liquid can flow between the plurality of tanks and supplies the processing liquid to the processing device by passing through the plurality of tanks in sequence; a heating unit that heats the processing liquid; a dilution unit that dilutes the processing liquid with a dilution liquid; a new liquid supply unit that supplies new processing liquid; a common flow path through which the processing liquids of the plurality of tanks flow; a switching unit that switches which of the tanks the processing liquid flowing through the common flow path is the processing liquid of; a concentration meter provided in the common flow path; and a control device that causes the concentration meter to switch the switching unit to measure the concentration of each of the processing liquids for each of the tanks, and controls at least one of the heating unit, the dilution unit, and the new liquid supply unit so that the concentration of the processing liquid becomes a predetermined target value.

[0015] A substrate processing apparatus according to an embodiment of the present invention includes the processing apparatus and the processing liquid supply apparatus.

[0016] According to an embodiment of the present invention, there is provided a processing liquid supplying method for supplying a processing device for processing a substrate with a processing liquid by passing the processing liquid through a plurality of tanks in sequence, the method including: measuring a concentration of the processing liquid for each of the tanks by switching the tanks of the processing liquid flowing through the common flow path using a concentration meter provided in a common common flow path through which the processing liquid of the plurality of tanks flows; and measuring a concentration of the processing liquid for each of the tanks by switching the tanks of the processing liquid flowing through the common flow path, and measuring a concentration of the processing liquid for each of the tanks by a heating unit that heats the processing liquid, a dilution unit that dilutes the processing liquid, and a dilution unit that dilutes the processing liquid so that the concentration of the processing liquid reaches a predetermined target value. of New liquid supply section to supply of At least one of them is controlled to adjust the concentration of the treatment liquid. Effect of the Invention

[0017] An embodiment of the present invention can provide a processing liquid supply device, a substrate processing apparatus, and a processing liquid supply method that can adjust the concentration of the processing liquid supplied while reducing costs and preventing variation in the measured values ​​of the processing liquid concentration in each tank. [Brief description of the drawings]

[0018] [Figure 1] 1 is a simplified configuration diagram showing a processing apparatus and a processing liquid supplying apparatus according to an embodiment; [Diagram 2] 5 is a graph showing an example of concentration control performed by the treatment liquid supplying device according to the embodiment. [Diagram 3] 10 is a graph showing another example of concentration control by the treatment liquid supplying apparatus according to the embodiment. [Figure 4] FIG. 13 is a simplified configuration diagram showing a modified example of the processing device and the processing liquid supplying device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. [overview] As shown in Fig. 1, the processing liquid supplying apparatus 1 of the embodiment is an apparatus that supplies processing liquid L to a processing apparatus 100 that processes a substrate W with processing liquid L by passing through multiple tanks T in sequence. The processing liquid supplying apparatus 1 is provided with one concentration meter D in a common flow path C through which the processing liquid L flows from the multiple tanks T, and measures the concentration of the processing liquid L in each tank T while switching the tanks T of the processing liquid L flowing through the common flow path C by a switching unit SW, and adjusts the amount of dilution liquid added to the processing liquid L in each tank T and the temperature to which the processing liquid L is heated so that the processing liquid L in each tank T has a predetermined target concentration. In the following description, an apparatus that performs processing while circulating the processing liquid L between the processing liquid supplying apparatus 1 and the processing apparatus 100 is referred to as a substrate processing apparatus SS.

[0020] [Processing device] The processing apparatus 100 is, for example, a single-wafer etching apparatus that removes unnecessary films and leaves circuit patterns by supplying a processing liquid L to a rotating substrate W. In the following description, an active ingredient for processing in the processing liquid L is called a chemical liquid. Also, the concentration refers to the concentration of the chemical liquid contained in the processing liquid L. In this embodiment, an aqueous solution containing phosphoric acid (H3PO4) (hereinafter, referred to as a phosphoric acid solution) which is a chemical liquid is used as the processing liquid L. The phosphoric acid solution needs to be heated to a high temperature in order to ensure a processing rate, and it is highly necessary to prevent a temperature drop. However, the processing liquid L used is not limited to this, and a wide variety of acid-based liquids can be used, such as a mixture of hydrofluoric acid and nitric acid, a mixture of acetic acid, sulfuric acid, and hydrogen peroxide (SPM: Sulfuric hydrogen peroxide mixture), etc.

[0021] The processing apparatus 100 is a single-wafer processing apparatus that processes substrates W one by one. The processing apparatus 100 has a rotating section 101, a supply section 102, and a recovery section 103, which are arranged in a chamber 100a that is a container. The rotating section 101 has a rotating body 101a and a driving source 101c. The rotating body 101a is a rotary table that holds the edge of the substrate W with a holding section 101b such as a chuck pin and rotates about an axis perpendicular to the substrate W. The driving source 101c is a motor that rotates the rotating body 101a.

[0022] The supply unit 102 has a nozzle 102a and an arm 102b. The nozzle 102a is a discharge unit that discharges the processing liquid L toward the processing surface of the rotating substrate W. The arm 102b is provided with the nozzle 102a at its tip, and swings the nozzle 102a between above the center of the rotating body 101a and a position retracted from the rotating body 101a. The nozzle 102a is connected to the processing liquid supply device 1 via a supply pipe S1 described later, and the processing liquid L is supplied to the nozzle 102a.

[0023] The recovery unit 103 is a housing provided to surround the rotating body 101a and recovers, from its bottom, the processing liquid L that is supplied from the nozzle 102a to the processing surface of the substrate W and leaks from the edge surface of the substrate W. Openings are provided at the bottom of the recovery unit 103 and the bottom of the chamber 100a, and these openings are connected to the processing liquid supplying device 1 via recovery piping R2, which will be described later.

[0024] [Processing liquid supply device] The processing liquid supplying apparatus 1 supplies a processing liquid L to the processing apparatus 100. The processing liquid supplying apparatus 1 also recovers the processing liquid L that has been processed in the processing apparatus 100, and supplies it to the processing apparatus 100 together with newly supplied processing liquid L. Although not shown in FIG. 1, a plurality of processing apparatuses 100 are provided for one processing liquid supplying apparatus 1.

[0025] The processing liquid supplying device 1 includes a tank T, a supply path S, a heating section H, a dilution section I, a common flow path C, a concentration meter D, and a control device E. The tank T stores the processing liquid L. The tank T includes a plurality of tanks, for example, a supply tank T1, a recovery tank T2, a buffer tank T3, and a new liquid tank T4. Hereinafter, when there is no need to distinguish between these tanks T1 to T4, they will be described as tank T.

[0026] The supply path S connects the multiple tanks T1-T4 so that the processing liquid L can flow between the multiple tanks T1-T4, and supplies the processing liquid L to the processing device 100 by passing through the multiple tanks T1-T4 in sequence. The supply path S includes supply pipes S1-S4. The heating unit H heats the processing liquid L. The heating unit H includes heaters H1-H4. Note that passing through the multiple tanks T in sequence may mean passing through two or more tanks T among the multiple tanks T that store the processing liquid L. In other words, it is sufficient that at least two tanks T are connected so that the processing liquid L can flow between them.

[0027] (Supply Tank) The supply tank T1 has a container 10a, and stores therein the processing liquid L to be supplied to the processing device 100. The container 10a is made of a material that is corrosion-resistant to the processing liquid L. A supply pipe S1 and a return pipe R1 are connected to the supply tank T1. The supply pipe S1 is connected to the bottom of the container 10a, and supplies the processing liquid L to a supply unit 102 of the processing device 100.

[0028] A pump P1, a heater H1, a filter F, and a valve V1a are provided on the supply pipe S1. The pump P1 sucks and delivers the processing liquid L from the bottom of the supply tank T1. The heater H1 is provided downstream of the pump P1 and heats the processing liquid L delivered from the pump P1 to a predetermined target temperature. In this case, the supply tank T1 side in the flow from the supply tank T1 to the processing device 100 is upstream, and the processing device 100 side is downstream. A temperature sensor (not shown) is provided downstream of the heater H1, and the output of the heater H1 is adjusted based on feedback from the temperature sensor. The temperature sensor is, for example, a thermistor. The processing liquid L heated to the target temperature by the heater H1 is supplied to the supply unit 102 of the processing device 100.

[0029] The filter F is provided downstream of the heater H1 and removes impurities from the processing liquid L flowing through the supply pipe S1. The valve V1a is provided downstream of the filter F and switches between supplying and not supplying the processing liquid L to the processing device 100.

[0030] The return pipe R1 branches off upstream of the valve V1a of the supply pipe S1 and is connected to the supply tank T1. A valve V1b is provided in the return pipe R1. When the processing of the substrate W is not being performed, the processing liquid L supplied to the processing apparatus 100 from the supply pipe S1 is returned to the supply tank T1 via the return pipe R1 by closing the valve V1a and opening the valve V1b. That is, a circulation path is formed by the return pipe R1 and the supply pipe S1. In this circulation path, the temperature of the processing liquid L in the supply tank T1 is maintained at a constant temperature by heating with the heater H1.

[0031] Although not shown, the supply tank T1 is provided with a liquid level sensor for detecting the liquid level. This makes it possible to detect whether the processing liquid L in the supply tank T1 has fallen below a certain amount. A heater for heating the processing liquid L to a certain temperature may be provided in the container 10a of the supply tank T1.

[0032] (Recovery tank) The recovery tank T2 has a container 20a, and stores the processing liquid L recovered from the processing device 100 in the container 20a. The container 20a is made of a material that is corrosion-resistant against the processing liquid L. A recovery pipe R2 and a supply pipe S2 are connected to the recovery tank T2. The recovery pipe R2 is a pipe that recovers the processing liquid L after the etching process from the recovery unit 103 of the processing device 100.

[0033] The supply pipe S2 is connected to the bottom of the container 20a. The supply pipe S2 is provided with a pump P2 and a heater H2. The pump P2 sucks and sends out the processing liquid L from the bottom of the recovery tank T2. The heater H2 is provided downstream of the pump P2 and heats the processing liquid L sent out from the pump P2 to a predetermined target temperature. Note that here, the bottom side of the recovery tank T2 in the flow from the bottom of the recovery tank T2 toward a buffer tank T3, an upper part (return) of the recovery tank T2, or a common flow path C described later is defined as upstream, and the opposite side is defined as downstream. A temperature sensor (not shown) is provided downstream of the heater H2, and the output of the heater H2 is adjusted based on feedback from the temperature sensor. The temperature sensor is, for example, a thermistor.

[0034] There is a branch point in the supply pipe S2, and from this branch point, the pipe branches into a path that sends the liquid to a buffer tank T3 (described later) and a path that returns to the recovery tank T2. Valves V2a and V2b are provided on each of the branched paths. The valve V2a switches between supplying the processing liquid L to the buffer tank T3 and not supplying it. The valve V2b switches between returning the processing liquid L to the recovery tank T2 and not returning it.

[0035] By closing the valve V2a and opening the valve V2b, the processing liquid L heated by the heater H2 is usually returned to the recovery tank T2, so that the processing liquid L is circulated. In this way, the heater H2 heats the processing liquid L in the recovery tank T2 to the target temperature. However, when the processing liquid L in the buffer tank T3 falls below a certain amount and needs to be replenished, the valve V2a opens and the valve V2b closes, so that the processing liquid L heated to the target temperature is supplied to the buffer tank T3. In this way, the recovered and reheated processing liquid L can be reused.

[0036] Although not shown, the recovery tank T2 is provided with a liquid level sensor for detecting the liquid level. This makes it possible to detect whether the amount of the processing liquid L in the recovery tank T2 has fallen below a certain level. By detecting whether the amount of the processing liquid L has fallen below a certain level, it is possible to determine whether to supply the processing liquid L to the buffer tank T3. In other words, when the amount of the processing liquid L falls below a certain level, the processing liquid L is not supplied to the buffer tank T3, but continues to circulate to the recovery tank T2. When the amount of the processing liquid L exceeds a certain level, the temperature and concentration of the processing liquid L are adjusted, and then the supply to the buffer tank T3 is started. A heater for heating the processing liquid L to a certain temperature may be provided in the recovery tank T2.

[0037] (Buffer tank) The buffer tank T3 has a container 30a, and stores the processing liquid L from the recovery tank T2 in the container 30a. The container 30a is made of a material that is resistant to corrosion by the processing liquid L. The buffer tank T3 is connected to a supply pipe S3 and the above-mentioned supply pipe S2.

[0038] The supply pipe S3 is connected to the bottom of the container 30a. The supply pipe S3 is provided with a pump P3 and a heater H3. The pump P3 sucks and pumps out the processing liquid L from the bottom of the buffer tank T3. The heater H3 is provided downstream of the pump P3. P3The heater H3 heats the processing liquid L delivered from the heater H3 to a predetermined target temperature. In this case, the bottom side of the buffer tank T3 in the flow from the bottom of the buffer tank T3 to the supply tank T1, the upper part (return) of the buffer tank T3, or the common flow path C is defined as the upstream side, and the opposite side is defined as the downstream side. A temperature sensor (not shown) is provided downstream of the heater H3, and the output of the heater H3 is adjusted based on feedback received from the temperature sensor. The temperature sensor is, for example, a thermistor.

[0039] There is a branch point in the supply pipe S3, and from this branch point, it branches into a path that sends the liquid to the supply tank T1 and a path that returns to the buffer tank T3. Valves V3a and V3b are provided on each of the branched paths. The valve V3a switches between supplying the processing liquid L to the supply tank T1 and not supplying it. The valve V3b switches between returning the processing liquid L to the buffer tank T3 and not returning it.

[0040] By closing the valve V3a and opening the valve V3b, the processing liquid L heated by the heater H3 is usually returned to the buffer tank T3, so that the processing liquid L is circulated. In this way, the heater H3 heats the processing liquid L in the buffer tank T3 to a target temperature. However, when the processing liquid L in the supply tank T1 falls below a certain amount and needs to be replenished, the valve V3a opens and the valve V3b closes, so that the processing liquid L heated to the target temperature is supplied to the supply tank T1.

[0041] Although not shown, the buffer tank T3 is provided with a liquid level sensor for detecting the liquid level. This makes it possible to detect whether the amount of the processing liquid L in the buffer tank T3 has fallen below a certain level. By detecting whether the amount of the processing liquid L has fallen below a certain level, it is possible to determine whether the processing liquid L is to be supplied from the recovery tank T2. In other words, when the amount of the processing liquid L falls below a certain level, the processing liquid L is supplied from the recovery tank T2 and continues to circulate to the buffer tank T3 without being supplied to the supply tank T1. When the amount of the processing liquid L exceeds a certain level, the processing liquid L is not supplied from the recovery tank T2, and the temperature and concentration of the processing liquid L are adjusted to their respective target values, i.e., the target temperature and target concentration, and then the processing liquid L is supplied to the supply tank T1. A heater for heating the processing liquid L to a constant temperature may be provided in the buffer tank T3.

[0042] Furthermore, pipes equipped with valves Vz are connected to the bottoms of the supply tank T1, recovery tank T2, and buffer tank T3, respectively, and merge into a common pipe, the drain line Z. The drain line Z is connected to the waste liquid route of the factory.

[0043] (New liquid tank) The new liquid tank T4 has a container 40a, and stores a newly prepared processing liquid L (hereinafter referred to as new liquid) in the container 40a. The container 40a is made of a material that is corrosion-resistant against the processing liquid L. A liquid delivery pipe R3 and a supply pipe S4 are connected to the new liquid tank T4. The liquid delivery pipe R3 is a pipe that supplies the processing liquid L from a supply source of the processing liquid L (not shown) to the new liquid tank T4.

[0044] The supply pipe S4 is connected to the bottom of the container 40a. The supply pipe S4 is provided with a pump P4 and a heater H4. The pump P4 sucks and sends out the processing liquid L from the bottom of the new liquid tank T4. The heater H4 is provided downstream of the pump P4 and heats the processing liquid L sent out from the pump P4 to a predetermined target temperature. In this case, the bottom side of the new liquid tank T4 in the flow from the bottom of the new liquid tank T4 to the recovery tank T2, the buffer tank T3, the supply tank T1, the upper part (return) of the new liquid tank T4, or the common flow path C is upstream, and the opposite side is downstream. A temperature sensor (not shown) is provided downstream of the heater H4, and the output of the heater H4 is adjusted based on feedback from the temperature sensor. The temperature sensor is, for example, a thermistor.

[0045] The supply pipe S4 branches into a liquid delivery path that delivers liquid to the recovery tank T2, the buffer tank T3, and the supply tank T1, and a path that returns to the new liquid tank T4. The liquid delivery path branches to the recovery tank T2, the buffer tank T3, and the supply tank T1, and valves V4a, V4c, and V4d are provided on each branch. The valves V4a, V4c, and V4d switch between sending and not sending the processing liquid L to the recovery tank T2, the buffer tank T3, and the supply tank T1, respectively. The liquid delivery path and the valves V4a, V4c, and V4d are a new liquid supply unit J that supplies new liquid to at least one of the recovery tank T2, the buffer tank T3, and the supply tank T1. The path that returns to the new liquid tank T4 is provided with a valve V4b. The valve V4b switches between returning and not returning the processing liquid L to the new liquid tank T4.

[0046] By opening the valve V4b, the processing liquid L heated by the heater H4 is usually returned to the new liquid tank T4, so that the processing liquid L is circulated. As a result, the heater H4 heats the processing liquid L in the new liquid tank T4 to a target temperature. Furthermore, when the new liquid becomes usable as the processing liquid L, and the processing liquid L in the supply tank T1 falls below a certain amount, and the processing liquid L in the buffer tank T3 also falls below a certain amount, the valve V4b is closed, the valve V4d is opened, and a predetermined certain amount of the liquid is sent to the supply tank T1. As a result, the processing liquid L is supplied to the processing device 100 and used for processing, and the processing liquid L that is insufficient when supplied from the buffer tank T3 is replenished. The supply of the new liquid from the new liquid tank T4 to the recovery tank T2 is performed by closing the valve V4b and opening the valve V4a. However, new liquid is supplied to the recovery tank T2 only when the processing liquid L in the recovery tank T2 falls below a certain amount and the situation continues in which no recovered liquid is entering from the processing device 100, so that the recovery tank T2 does not overflow with the recovered liquid and new liquid.

[0047] The new liquid tank T4, which has been used to replenish the supply tank T1 with the processing liquid L, is supplied with the same amount of new liquid through the liquid delivery pipe R3, and the next heating is performed. Note that the buffer tank T3 is also replenished with new liquid by opening the valve V4c when the processing liquid L in the buffer tank T3 falls below a certain amount and the supply from the recovery tank T2 is insufficient.

[0048] Although not shown, the new liquid tank T4 is provided with a liquid level sensor for detecting the liquid level. This makes it possible to detect whether the processing liquid L in the new liquid tank T4 has fallen below a certain amount, and to determine whether it is necessary to replenish the processing liquid L by sending the processing liquid from the liquid sending pipe R3. A heater for heating the processing liquid L to a certain temperature may be provided in the new liquid tank T4.

[0049] (Dilution part) The dilution unit I dilutes the processing liquid L with a dilution liquid. The dilution liquid is a liquid that reduces the concentration of the liquid in the tank T, and in this embodiment is pure water. The dilution unit I has a liquid supply pipe R4. The liquid supply pipe R4 branches from a pure water supply source (not shown) to a supply tank T1, a recovery tank T2, a buffer tank T3, and a new liquid tank T4, and supplies the dilution liquid to each of them. A valve V5 is provided on each of the branched pipes to the tanks T1 to T4. A predetermined amount of pure water is added to each of the tanks T1 to T4 based on the concentration measurement of the processing liquid L in each of the tanks T1 to T4 by a concentration meter D described later.

[0050] (Common flow path) The common flow path C is a common path through which the processing liquid L of the multiple tanks T1 to T4 flows. The common flow path C in this embodiment is a pipe where pipes t1 to t4 branched from the supply pipes S1 to S4 join. That is, a branch point is provided downstream of the filter F of the supply pipe S1, and the pipe t1 branches from this branch point. The pipe t2 branches from the branch point of the supply pipe S2 to the buffer tank T3 and the recovery tank T2. The pipe t3 branches from the branch point of the supply pipe S3 to the supply tank T1 and the buffer tank T3. Furthermore, the pipe t4 branches from the branch point of the supply pipe S4 to the supply pipe S1, etc. and the new liquid tank T4. The pipes t1 to t4 from the supply pipes S1 to S4 are each provided with a valve V6a. The common flow path C is also connected to pipes bp1 to bp4 that branch to the multiple tanks T1 to T4 and return them. A valve V6b is provided in each of the pipes bp1-bp4 branching off from the common flow path C toward the tanks T1-T4. These valves V6a and V6b are switching units SW that switch the processing liquid L flowing through the common flow path C to the processing liquid L of one of the tanks T1-T4, depending on which one is opened.

[0051] (densitometer) The concentration meter D is provided in the common flow path C and measures the concentration of the processing liquid L flowing through the common flow path C. The supply of the processing liquid to the concentration meter D and the return to the tank T are distinguished for each of the tanks T1 to T4 by switching the valves V6a and V6b of the switching unit SW, and are performed so as not to mix the processing liquid L between the tanks T1 to T4. In other words, the processing liquid L discharged from the same tank T is returned to the same tank T so that the processing liquid L accumulated in at least the common flow path C is not mixed. In this embodiment, one concentration meter D is provided in the common flow path C. It is preferable to use an optical concentration meter D with relatively high accuracy.

[0052] (Control device) The control device E controls each part of the substrate processing apparatus SS. The control device E has a processor that executes a program to realize various functions of the substrate processing apparatus SS, a memory that stores various information such as the program and operating conditions, and a drive circuit that drives each element. The control device E also has an input device for inputting information and a display device for displaying information.

[0053] The control device E includes a substrate processing control section 21, a concentration control section 22, and a storage section 23. The substrate processing control section 21 controls each section of the processing device 100 and the processing liquid supplying device 1 to process the substrate W. That is, the substrate processing control section 21 controls the loading and unloading of the substrate W into and from the chamber 100a, the holding of the substrate W by the holding section 101b, the rotation of the rotating body 101a by the driving source 12, the swinging of the nozzle 102a by the arm 102b, the supply or non-supply of the processing liquid L by switching the valves V1a and V1b, and the replenishment of the processing liquid L to each of the tanks T1 to T4 by switching the valves V2a, V2b, V3a, V3b, V4a, and V4b.

[0054] The concentration control unit 22 controls the concentration meter D to measure the concentration of the treatment liquid L in each of the tanks T1 to T4, and controls the heating unit H and the dilution unit I so that the concentration of the treatment liquid L becomes a predetermined target value (target concentration). The target concentration includes the set concentration and is within a predetermined range around it. concentrationis, for example, 87.7%. In this concentration control, the temperature of the processing liquid L is also controlled to a predetermined target value (target temperature) as described above. The target temperature includes the set temperature and is within a predetermined range around it. The set temperature is, for example, 160°C. The concentration control unit 22 calculates the output of the heating unit H and the amount of dilution liquid added based on either or both of the difference between the measured value and the target value (target concentration, target temperature) and the amount of change in the measured value, and controls the heating unit H and the dilution unit I. When calculating the difference between the measured value and the target value, the set concentration and set temperature are used, but it is not necessary to control the concentration to exactly match these set concentrations and set temperatures, and it is sufficient to control the concentration to fall within the range of the target concentration and target temperature. The control based on the amount of change in the measured value means that, when there is a period during which the measurement is continuing, the concentration after the period until the next concentration measurement is performed is estimated from the value of the amount of change in concentration (slope of the graph) during that measurement period, and the current output of the heating unit H and the amount of dilution liquid added are calculated. That is, this is a method for determining the amount of adjustment based on how much the concentration will decrease until the next concentration measurement time.

[0055] More specifically, the concentration control unit 22 switches between tanks T1-T4 for measuring the concentration by switching valves V6a and V6b of the switching unit SW between open and closed states. The switching between tanks T1-T4 is performed at predetermined time intervals set for each tank T1-T4. In addition, the concentration control unit 22 switches between the outputs of heaters H1-H4 of the heating unit H and the open and closed state of valve V5 of the dilution unit I to concentrate the processing liquid L by heating it and dilute it by adding pure water.

[0056] By setting the time interval, the measurement time of all tanks T can be the same or each tank T can be different. For example, the measurement time of a specific tank T can be made longer or shorter. For tanks T that require highly accurate control, the frequency of concentration measurement can be increased or the measurement time can be increased, and for tanks T that only require rough adjustment, the frequency of concentration measurement can be decreased or the measurement time can be shortened. However, in the case of the same measurement time, it is preferable to increase the measurement frequency rather than ensuring a long measurement time for one measurement. This makes it possible to measure a large number of tanks T within a certain time and adjust the respective concentrations, so that the measured values ​​corresponding to each tank T can easily converge to the target value. When switching the tank T for which the concentration is to be measured, the measurement begins after flowing an amount of treatment liquid L sufficient to replace the treatment liquid L of the previous tank T accumulated in the common flow path C with the treatment liquid L of the switched tank T, or after the time required for replacement has elapsed.

[0057] The storage unit 23 is configured as a memory and stores a target concentration, a target temperature, a time interval, and the like. The operator can input desired values ​​for the target concentration, the target temperature, and the time interval using an input device. For example, the concentration can be adjusted by increasing the frequency of measurement for the recovery tank T2, which recovers the processing liquid L, which is used in processing and therefore has large fluctuations in concentration and temperature, compared to the other tanks T and lengthening the measurement time. In addition, the frequency of measurement for the supply tank T1, which has a direct effect on the substrate processing, may be increased compared to the other tanks T to stabilize the processing of the substrates W.

[0058] [Operation] The operation of the substrate processing apparatus SS of the present embodiment as described above will be described with reference to Fig. 2 and Fig. 3 in addition to Fig. 1. Note that a substrate processing method for processing a substrate W in the following procedure is also one aspect of this embodiment.

[0059] (Substrate processing) First, the substrate processing by the processing device 100 will be described. The substrate W to be processed is loaded onto the rotating body 101a by a transport robot and held by a holder 101b. A driving source 101c rotates the rotating body 101a to rotate the substrate W. The processing liquid L, which has been adjusted to a desired concentration and temperature by the processing liquid supplying device 1, is supplied from a nozzle 102a through the opening of a valve V1a to the surface to be processed of the substrate W, thereby performing an etching process.

[0060] After a predetermined processing time has elapsed, the valve V1a is closed to stop the supply of the processing liquid L. Thereafter, the substrate W stops rotating, and the transfer robot unloads the substrate W, which is released from the holder 101b, from the chamber 100a.

[0061] (Supply of processing liquid) Next, a description will be given of the adjustment process of the processing liquid L by the processing liquid supplying apparatus 1. Before being supplied to the processing apparatus 100, the processing liquid L in the supply tank T1 is heated by the heater H1 while circulating through the supply pipe S1, the return pipe R1, and the supply tank T1 with the valve V1a closed and the valve V1b open, so that the processing liquid L is maintained at a target temperature. Then, the processing liquid L in the supply tank T1 is supplied to the processing apparatus 100 at the timing of processing in the processing apparatus 100 as described above.

[0062] Before being supplied to the supply tank T1, the processing liquid L in the buffer tank T3 is heated by the heater H3 while circulating through the supply pipe S3 and the buffer tank T3 with the valve V3a closed and the valve V3b open, so that the processing liquid L is maintained at a target temperature. When the processing liquid L in the supply tank T1 falls below a certain amount, the valve V3a is opened and the valve V3b is closed, so that the processing liquid L is supplied to the supply tank T1.

[0063] Before being supplied to the buffer tank T3, the processing liquid L in the recovery tank T2 is heated by the heater H2 while circulating through the supply pipe S2 and the recovery tank T2 with the valve V2a closed and the valve V2b open, so that the processing liquid L is maintained at a target temperature. When the processing liquid L in the buffer tank T3 falls below a certain amount, the valve V2a is opened and the valve V2b is closed, so that the processing liquid L is supplied to the buffer tank T3.

[0064] Before being supplied to the recovery tank T2, the buffer tank T3, and the supply tank T1, the processing liquid L in the new liquid tank T4 is circulated through the supply pipe S4 and the new liquid tank T4 with the valves V4a, V4c, and V4d closed and the valve V4b open. H4 The target temperature is maintained by heating the processing liquid L in the buffer tank T3. When the amount of processing liquid L in the buffer tank T3 falls below a certain level and cannot be supplied to the supply tank T1, and when the amount of liquid in the supply tank T1 also falls below a certain level, the valve V4d is opened and the valve V4b is closed to supply new liquid from the new liquid tank T4 to the supply tank T1. Similarly, when the supply of processing liquid L in the recovery tank T2 and the buffer tank T3 is insufficient and the amount of processing liquid L falls below a certain level, the valves V4a and V4c may be opened to supply new liquid to the recovery tank T2 and the buffer tank T3. 。

[0065] (Concentration control) As described above, the concentration control performed in the process in which the processing liquid L is supplied to the processing device 100 by passing through each tank T1 to T4 in sequence will be described. First, the concentration measurement is performed by opening one of the valves corresponding to each set of t1-T1, t2-T2, t3-T3, and t4-T4 in the valves V6a and V6b of the switching unit SW and closing the others in sequence at a predetermined time interval, thereby switching the tanks T1 to T4 of the processing liquid L flowing through the common flow path C, and measuring the concentration with the concentration meter D. This makes it possible to selectively flow the processing liquid L from the tanks T1 to T4 through the common flow path C, so that the concentration of each tank T1 to T4 can be measured with one concentration meter D at a predetermined time interval.

[0066] Then, depending on the difference between the measured concentration and the target concentration, if concentration is required, the output of the heater H1-H4 of the corresponding tank T1-T4 is increased. If dilution is required, the valve V5 of the piping of the dilution unit I to the corresponding tank T1-T4 is opened to add a predetermined amount of pure water. Note that the controlled amount in the following description refers to adjusting the output of the heating unit H and the amount of added pure water depending on the difference between the measured concentration and the target concentration.

[0067] An example of such concentration control will be described with reference to the graphs of Figures 2 and 3. Figure 2 shows an example in which the concentration meter D is used to measure and adjust the concentration in each of the tanks T1 to T3, with the thick solid line indicating the change over time in the concentration value. In this example, the tanks are in the order of supply tank T1, buffer tank T3, supply tank T1, and recovery tank T2, with measurements being taken in supply tank T1 every other tank, and measurements being taken in buffer tank T3 and recovery tank T2 every third tank, to clearly show the transition in concentration in each of supply tank T1, buffer tank T3, and recovery tank T2.

[0068] First, the following description focuses only on the concentration of the processing liquid L in the buffer tank T3. Since the concentration meter D measures the concentration by switching between multiple tanks T at a predetermined time interval, the control amount for the concentration control of the tanks T is changed only while the concentration of each tank T is being measured. In other words, the control amount for the processing liquid L in the buffer tank T3 is switched while the concentration of the processing liquid L in the buffer tank T3 is being measured ([1], [2], and [3] in the figure).

[0069] As shown in [1] of FIG. 2, the concentration of the processing liquid L in the buffer tank T3 measured by the concentration meter D is higher than 87.7% of the set concentration. Therefore, a control is performed to add an amount of pure water determined based on the difference d1 between the measured concentration and the set concentration to reduce the concentration of the processing liquid L in the buffer tank T3. The amount of pure water added is set to an amount that will not cause the concentration to fall below the set concentration even if the addition is continued until the next measurement. As a result, even when the concentration meter D is measuring the concentration of the processing liquid L supplied from another tank T, the concentration value tends to decrease toward the target concentration. During this time, the measurement target of the concentration meter D is switched to another tank T, and the concentration of that tank T is controlled.

[0070] The concentration control of the buffer tank T3 is maintained at the concentration control set during measurement until the next concentration measurement is performed. In this example, as shown by the arrows in FIG. 2, the addition of the set amount of pure water is continued from [1] to [2] and from [2] to [3]. As shown in FIG. 2 [2], when the next concentration measurement of the buffer tank T3 is performed, if there is no change in the amount of the processing liquid L in the buffer tank T3, the concentration of the processing liquid L will be closer to the target concentration than the previous measured concentration value in [1] because the concentration of the processing liquid L has decreased due to the addition of pure water. Then, based on the difference d2 between the measured concentration and the set concentration, the amount of pure water added is set smaller than the previous time, and the concentration control of the buffer tank T3 is performed. The same applies to the control in the next [3].

[0071] In this way, even if the time for measuring the concentration is divided into short intervals, the target concentration can be approached by repeating this operation by setting the control amount (amount of pure water added) until the next measurement according to the difference from the set concentration at that time. When the concentration of the processing liquid L in the buffer tank T3 approaches the target concentration, the concentration of the processing liquid L in the buffer tank T3 can be stably maintained by setting the amount of water added that balances the increase in concentration caused by heating by the heater H3.

[0072] When the liquid level drops due to the liquid being sent from the buffer tank T3 to the supply tank T1, the liquid is replenished from the recovery tank T2, causing the concentration of the treatment liquid L in the buffer tank T3 to deviate from the controlled concentration value. In this case, the next concentration measurement will result in a control setting according to the new measured concentration.

[0073] For example, in the process of controlling the concentration to be reduced as shown in [1] to [3] of FIG. 2, if the concentration of the processing liquid L becomes lower than the target concentration, and the concentration of the processing liquid L exceeds the target concentration in the next measurement, it becomes necessary to perform reverse control (heating) to return the concentration to the target concentration, and it becomes difficult to stably maintain the concentration within an allowable range including the target concentration. For this reason, regarding the setting of the control amount, if it is calculated that the concentration will fall too much below the target concentration if the current amount of added pure water is continued until the next measurement time, the amount of added pure water is changed to an amount that will not cause the concentration to fall below the target concentration. In addition, while a tolerance range is set for the target concentration, the amount of added pure water is adjusted to aim for the upper limit of this tolerance range. For example, if pure water is added based on the measurement result in [1], when this amount is measured in [2], the amount of added pure water until the measurement time in [3] is changed from the amount of concentration change due to the amount of added pure water in [1].

[0074] Next, the supply tank T1 will be described. In the example shown in FIG. 2, the supply tank T1, which performs concentration measurement and control for every other tank, directly supplies the processing liquid L to the substrate W, and is therefore controlled in a state in which the target concentration is maintained from the beginning. In other words, the control is performed to maintain the concentration in a state in which heating and water addition are balanced, but in reality, the amount of the processing liquid L in the supply tank T1 decreases as the processing liquid L is sent to the processing device 100, and the concentration value changes as the processing liquid L is replenished from the buffer tank T3. By adding pure water and heating so that the concentration can be maintained even for this fluctuation, the deviation from the target concentration is reduced. In other words, the concentration is maintained within a predetermined allowable range.

[0075] Further, the following description focuses on the recovery tank T2. In the recovery tank T2, it is often necessary to control the concentration increase from a low concentration side that is lower than the target concentration, i.e., the concentration within a predetermined allowable range. This is because even if the processing liquid L is recovered in the recovery tank T2, it is highly likely that the processing liquid L will be recovered at a low concentration and low temperature due to mixing with pure water during rinsing. In this case, instead of adding pure water, the processing liquid L circulated by the pump P2 is heated by the heater H2 according to the difference between the measured concentration and the set concentration, and the water in the processing liquid L is evaporated to increase the concentration of the processing liquid L.

[0076] When the processing liquid L boils due to heating, it reaches its saturation temperature. Since the etching rate reaches its maximum value at the saturation temperature, the target concentration is set to the saturation temperature, that is, near the saturation concentration at the boiling point. However, since processing with the processing liquid L in a boiling state is unstable, the temperature is set slightly lower than the boiling point. At low concentrations, concentration control is possible by heating. The greater the difference between the measured concentration and the set concentration, the more quickly the heater H2 can approach the target concentration by increasing its output.

[0077] When increasing the concentration from such a low concentration by heating, the circulating treatment liquid L will boil due to heating, so it is preferable to keep the resistance of the piping returning to the recovery tank T2 as small as possible to allow smooth volume expansion due to boiling steam and prevent an increase in the internal pressure of the heater H2. Since the temperature of the treatment liquid L that has boiled and increased in concentration also increases, the temperature inside the recovery tank T2 also increases. Note that when a heater is installed inside the recovery tank T2, boiling may occur at the heater's contact points, so it is also necessary not to set the output for the heating surface area too large.

[0078] 2, when the measured concentration of the processing liquid L in the recovery tank T2 reaches the target concentration, the concentration and temperature of the processing liquid L in the recovery tank T2 are stably maintained within an allowable range by adding pure water and heating the processing liquid L in the recovery tank T2 in such a manner as to compensate for the increase in concentration and the decrease in temperature due to the evaporation of water from the liquid surface and the decrease in temperature due to heat radiation from the circulation line by the pump P2. However, in reality, in addition to performing such concentration control, the processing liquid L is replenished to each of the tanks T1 to T4 in response to the use of the processing liquid L by the processing apparatus 100.

[0079] An example of concentration change taking into account such liquid replenishment between tanks T will be described with reference to Fig. 3. In the figure, the timings rp1 to rp4 of replenishment of the processing liquid L are indicated by open circles. Also, the transition of concentration in tanks T where concentration measurement has not been performed is indicated by dashed lines. As described above, when the processing liquid L from the supply tank T1 is supplied to the processing device 100 and the liquid level in the supply tank T1 drops, this is detected by the liquid level sensor, and the processing liquid L is replenished from the buffer tank T3.

[0080] If the concentration of the processing liquid L replenished from the buffer tank T3 is higher than the target concentration, the concentration of the processing liquid L in the supply tank T1 will rise to a concentration higher than the set concentration. However, if the amount of replenishment is small compared to the amount of processing liquid L in the supply tank T1, the change is slight. In rp1, it is assumed that the concentration of the buffer tank T3 was measured when the processing liquid L was replenished, and since the change in concentration in the buffer tank T3 can be confirmed by measurement, a concentration correction is performed that includes this change.

[0081] On the other hand, the concentration of the processing solution L in the supply tank T1 will be maintained at a slightly elevated concentration, but this can be corrected. That is, the change in concentration in the supply tank T1 can be roughly calculated from the measured concentration of the processing solution L in the buffer tank T3 and the replenishment amount. The control amount of the supply tank T1 is corrected by using the value of this change in concentration. However, since the correction may be within an allowable range of variation for the target concentration, whether or not to perform correction may be determined after calculation. That is, if the amount of change in concentration is within the range of the target concentration, no correction is performed, and if it is outside the range of the target concentration, correction is performed.

[0082] Also, as in rp2 and rp4, even if the concentration is not being measured in the buffer tank T3, when the processing liquid L is replenished, the concentration change can be calculated using the concentration value estimated from the maintained control amount. In this case as well, if the amount of concentration change is within the range of the target concentration, no correction is made, but if it is outside the range of the target concentration, correction is made.

[0083] Furthermore, rp3 is an example of liquid replenishment from the recovery tank T2 when the amount of the processing liquid L in the buffer tank T3 decreases and the liquid level drops. If the concentration of the processing liquid L in the buffer tank T3 decreases because the concentration of the processing liquid L in the recovery tank T2 is lower than the target concentration, the ongoing control amount of the concentration may cause excessive correction until the next measurement. Excessive refers to a situation in which, for example, the amount of pure water added is too much and the concentration falls below the target concentration at the time of the next measurement. In this case, the amount of pure water added is reduced and set to the side where the concentration increases (the side where heating becomes stronger). However, if the heating is excessive, the addition of pure water will be increased again, and the concentration will fluctuate above and below the target concentration. This situation is not stable and should be avoided. Therefore, when the target concentration is approached, control is performed so that the amount of pure water added becomes almost constant.

[0084] In addition, when the concentration of the processing liquid L in the buffer tank T3 or the recovery tank T2 does not need to be precisely accurate, or when the switching time of the tank T can be set to a short time, it may be acceptable to correct the control amount after the concentration measurement starts. These settings can be made after checking the actual concentration control state.

[0085] 2 and 3, there is no description of the concentration measurement of the processing liquid L in the new liquid tank T4. Since it is sufficient to perform measurement after the new liquid refilled in the new liquid tank T4 reaches a certain temperature due to boiling, it is sufficient to perform concentration measurement at a predetermined interval after this state is reached. In particular, when creating new liquid that requires additional waiting time, such as dissolving silica, measurements will be added at regular intervals after refilling becomes possible.

[0086] [effect] (1) This embodiment relates to a processing liquid supplying device 1 that supplies processing liquid L to a processing device 100 that processes a substrate W with processing liquid L, and includes a plurality of tanks T for storing the processing liquid L, a supply path S that connects the plurality of tanks T so that the processing liquid L can flow among the plurality of tanks T and supplies the processing liquid L to the processing device 100 by passing through the plurality of tanks T in sequence, a heating section H that heats the processing liquid L, a dilution section I that dilutes the processing liquid L with a dilution liquid, a new liquid supplying section J that supplies new processing liquid L, a common flow path C through which the processing liquid L of the plurality of tanks T flows, a switching section SW that switches which of the tanks T the processing liquid L flowing through the common flow path C belongs to, a concentration meter D provided in the common flow path C, and a control device E that switches the switching section SW to cause the concentration meter D to measure the concentration of each processing liquid L for each tank T, and controls at least one of the heating section H, the dilution section I, and the new liquid supplying section J so that the concentration of the processing liquid L becomes a predetermined target value.

[0087] Moreover, this embodiment is a processing liquid supplying method for supplying processing liquid L to a processing apparatus 100 that processes a substrate W with processing liquid L by passing the processing liquid L through a plurality of tanks T in sequence, and a concentration meter D provided in a common flow path C through which the processing liquid L of the plurality of tanks T flows is used to switch the tanks T of the processing liquid L flowing through the common flow path C and measure the concentration of each processing liquid L for each tank T. The concentration of the processing liquid L is adjusted by controlling a heating unit H that heats the processing liquid L, a dilution unit I that dilutes the processing liquid L, and a new liquid supply unit J that supplies new processing liquid so that the concentration of the processing liquid L becomes a predetermined target value.

[0088] Therefore, by measuring the concentration of the processing liquid L in each of the multiple tanks T at time intervals using one concentration meter D, the multiple tanks T can be measured substantially in parallel. Therefore, the concentration meters D of the multiple tanks T can be consolidated into one, and the occurrence of variations in the measured values ​​due to individual differences in the concentration meters D can be prevented. This allows the concentration of the processing liquid L in each tank T to accurately converge to a target value, improving the uniformity of processing. In addition, since the effort and time required to adjust the multiple concentration meters D to suppress variations is no longer necessary, production efficiency can be improved. Furthermore, since there is no need to provide a concentration meter D for each of the multiple tanks T, the configuration is simplified and costs can be reduced.

[0089] (2) At least one of a heating unit H, a dilution unit I, and a new liquid supply unit J is provided for each of the multiple tanks T so that the concentration of the processing liquid L can be controlled for each tank T. Since the multiple tanks T are measured with a single concentration meter D and the concentrations of the processing liquid L in the multiple tanks T can be individually controlled according to each measurement value, it becomes possible to appropriately adjust the concentration according to the magnitude of concentration fluctuations in each tank T.

[0090] (3) The time interval for measurement by the concentration meter D is set for each of the multiple tanks T. Therefore, by changing the length of the time interval for measurement and the frequency of measurement for each tank T depending on the difference in the amount of concentration adjustment required for each tank T, it is possible to easily converge to the target value. In this way, one concentration meter D can be effectively used for measuring and controlling the concentration of multiple tanks T.

[0091] (4) The control device E calculates the output of the heating unit H and the amount of dilution liquid to be added based on either or both of the difference between the measured value and the target value and the amount of change in the measured value, and controls the heating unit H and the dilution unit I. Therefore, the concentration of the treatment liquid L can be controlled by taking into account the convergence to the target value as well as fluctuations due to the replenishment of the treatment liquid L to each tank T.

[0092] (5) The multiple tanks T include a supply tank T1 that supplies processing liquid L to the processing apparatus 100, a recovery tank T2 that recovers processing liquid L that has been processed in the processing apparatus 100, a buffer tank T3 disposed between the recovery tank T2 and the supply tank T1, and a new liquid tank T4 that supplies new processing liquid L. This makes it possible to individually and optimally control the multiple tanks T that need to constantly supply processing liquid L at a stable concentration, such as in the single-wafer processing apparatus 100.

[0093] [Variations] The above embodiment can also be modified as follows. (1) Each tank T need only be an area for storing the processing liquid L, and does not necessarily have to be a separate and independent container. For example, in FIG. 4, partitions pa1 and pa2 may be provided in one container 50a, with one side functioning as the recovery tank T2, the other as the buffer tank T3, and the middle as the shared tank T5. Each partition pa1 and pa2 is provided with a notch to allow the processing liquid L to flow through a portion thereof, and the processing liquid L in the recovery tank T2 is sucked in by pump P2, causing the processing liquid L to flow from the shared tank T5 to the recovery tank T2. Similarly, pump P3 is used to Buffer Tank T3 As the processing liquid L is sucked, the processing liquid L flows from the common tank T5 to the buffer tank T3.

[0094] In the recovery tank T2, the used processing liquid L (recovered liquid) flows through the recovery pipe R2. The recovered liquid is collected at a low temperature. The recovered liquid is then sucked in by the pump P2, heated by the heater H2, and fed back to the supply pipe R2. S2The recovery liquid is sent to the common tank T5 via the heater H2. The recovery liquid heated by this heater H2 increases in temperature and in concentration due to evaporation of water, so that when it flows into the common tank T5, its concentration is higher than when it was recovered in the recovery tank T2.

[0095] The processing liquid L in the buffer tank T3 sucked by the pump P3 is sent to the supply tank T1, but the excess liquid level in the supply tank T1 is returned to the buffer tank T3 via the return pipe R5. The processing liquid L in the supply tank T1 is controlled by heating, adding pure water, etc., so that the target concentration is maintained. Therefore, by returning the excess in the supply tank T1 to the buffer tank T3, the concentration of the processing liquid L in the buffer tank T3 can be made close to the concentration of the processing liquid L in the supply tank T1.

[0096] In this way, by locally heating a portion of one container 50a, it is possible to perform concentration control and temperature control until the supply tank T1 can be replenished with the processing liquid L. Even with such a configuration of the tank T, it is possible to perform the necessary concentration control by measuring the concentration and performing heating and dilution accordingly.

[0097] (2) In the above embodiment, the concentration of all the tanks T1 to T4 is measured, but it is possible that the concentration of only some of the tanks T is not measured. For example, the amount of recovery liquid flowing into the recovery tank T2 does not always remain constant, so the amount of liquid fluctuates greatly. If the amount of liquid fluctuates, the concentration of the processing liquid L in the recovery tank T2 also fluctuates greatly. In this way, the amount and concentration of the recovery tank T2 fluctuates greatly, and concentration control in the buffer tank T3 may be sufficient in some cases, so that concentration measurement of the recovery tank T2 may not be performed. In addition, concentration measurement is not normally performed for some of the tanks T, but control by concentration measurement may be enabled when there is a possibility that a large concentration change has occurred, such as when the refill amount of the processing liquid L is different from normal.

[0098] (3) In the above embodiment, the processing liquid L is diluted by adding water, but it is also possible to dilute, i.e., reduce the concentration, by adding new liquid of low concentration. Furthermore, since it is sufficient that the concentration and temperature of the processing liquid L can be controlled to a predetermined value when it is supplied to the processing device 100, the target concentration of the buffer tank T3 and the recovery tank T2 does not necessarily have to be matched to the target concentration of the supply tank T1. In other words, the target concentration may be changed for each tank T. For example, if the heating capacity of the heater H1 is high, the temperature and concentration of the processing liquid L in the buffer tank T3 may be low. In particular, there is no problem if the concentration of the buffer tank T3 is slightly lower than the target concentration of the supply tank T1. This is because, even if the processing liquid L with a lower concentration and temperature than the target concentration flows from the buffer tank T3 to the supply tank T1, it can be easily adjusted to the target concentration if the heating capacity of the heater H1 that circulates and heats on the supply tank T1 side is high.

[0099] (4) In the above embodiment, the common flow path C is configured to sequentially switch between the processing liquid L from each tank T, but a cleaning liquid supply circuit for cleaning the inside of the concentration meter D may be connected to this common flow path C, and control may be incorporated that adds a cleaning time for the concentration meter D. In other words, the concentration meter D can be cleaned by controlling the cleaning liquid from the cleaning liquid supply circuit to flow into the concentration meter D every time or every predetermined number of times the substrate is processed. This makes it possible to maintain the accuracy of the concentration meter D and extend its lifespan.

[0100] It should be noted that the common flow path C may be provided with a flow path that drains water directly to the discharge path Z via the valve Vz. This allows the cleaning liquid to flow into the discharge path Z by opening the valve Vz when cleaning the concentration meter D. In addition, since the initial certain time period during which the liquid flows from each tank T to the concentration meter D is a process for replacing the previous processing liquid L, the timing of opening and closing the valve Vz may be set so that the liquid flows into the discharge path Z without being returned to the tank T.

[0101] [Other embodiments] Although the embodiment of the present invention and the modified examples of each part have been described above, these embodiments and the modified examples of each part are presented as examples and are not intended to limit the scope of the invention. These novel embodiments described above can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are included in the invention described in the claims. [Explanation of symbols]

[0102] 1 Processing liquid supply device 10a~40a container 12 Power source 20a: Container 21 Substrate processing control section 22 Concentration control section 23 Memory section 100 Processing equipment 100a Chamber 101 Rotating part 101a Rotating body 101b Holding part 101c Power source 102 Supply section 102a Nozzle 102b Arm 103 Collection Department C Common flow path D Densitometer E. Control device F Filter H heating section H1~H4 heater I Dilution section J New liquid supply section L Processing liquid P1~P4 pumps R1, R5 Return pipe R2 Recovery piping R3, R4 Liquid delivery piping S Supply Channel S1~S4 Supply piping SS Substrate Processing Equipment Switching section T Tank T1 Supply Tank T2 Recovery Tank T3 Buffer Tank T4 New Liquid Tank T5 Shared Tank t1~t4, bp1~bp4 piping V1a~V6b, Vz valves Z discharge path

Claims

1. 1. A processing liquid supplying apparatus for supplying a processing liquid to a processing apparatus for processing a substrate with the processing liquid, comprising: A plurality of tanks for storing the processing liquid; a supply path that connects the tanks so that the processing liquid can flow among the tanks and supplies the processing liquid to the processing device by passing the processing liquid through the tanks in sequence; A heating unit that heats the treatment liquid; a dilution unit that dilutes the treatment liquid with a dilution liquid; a new liquid supply unit for supplying new processing liquid; a common flow path through which the treatment liquid of the plurality of tanks flows; a switching unit that switches which of the tanks the treatment liquid circulating in the common flow path is the treatment liquid of; A concentration meter provided in the common flow path; a control device that causes the concentration meter to switch the switching unit to measure the concentration of the treatment liquid in each of the tanks, and controls at least one of the heating unit, the dilution unit, and the new liquid supply unit so that the concentration of the treatment liquid reaches a predetermined target value; A processing liquid supplying device having the same.

2. 2. The processing liquid supplying device according to claim 1, wherein at least one of the heating section, the dilution section and the new liquid supplying section is provided for each of the plurality of tanks so that the concentration of the processing liquid can be controlled for each of the tanks.

3. 3. The processing liquid supplying apparatus according to claim 1, wherein a time interval for measurement by said concentration meter is set for each of said plurality of tanks.

4. A processing liquid supply device as described in any one of claims 1 to 3, wherein the control device calculates the output of the heating section and the amount of dilution liquid to be added based on either or both of the difference between the measurement value of the concentration meter and the target value and the amount of change in the measurement value, and controls the heating section and the dilution section.

5. The plurality of tanks include a supply tank for supplying the processing solution to the processing device; a recovery tank for recovering the processing liquid that has been processed in the processing device; a buffer tank disposed between the recovery tank and the supply tank; a new liquid tank for supplying new processing liquid; 5. The processing liquid supplying apparatus according to claim 1, further comprising:

6. The processing device; A processing liquid supplying device according to any one of claims 1 to 5, A substrate processing apparatus comprising:

7. 1. A method for supplying a processing liquid to a processing device for processing a substrate with the processing liquid by passing the processing liquid through a plurality of tanks in sequence, comprising the steps of: a concentration meter provided in a common flow path through which the treatment liquids of the plurality of tanks flow is used to measure the concentration of each of the treatment liquids in each of the tanks by switching the tanks of the treatment liquid flowing through the common flow path; A processing liquid supply method for adjusting the concentration of the processing liquid by controlling at least one of a heating section that heats the processing liquid, a dilution section that dilutes the processing liquid, and a new liquid supply section that supplies new processing liquid, so that the concentration of the processing liquid becomes a predetermined target value.

8. 8. The method of supplying a processing liquid according to claim 7, further comprising the step of controlling at least one of the heating section, the dilution section and the new liquid supply section to adjust the concentration of the processing liquid for each of the tanks.

9. 9. The method of supplying a processing liquid according to claim 7, wherein the time interval for measurement by the concentration meter is set for each of the tanks.

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