Processing liquid supply device, substrate processing apparatus, and method for inspecting processing liquid supply device

Abstract

To provide a processing liquid supply device for testing the functionality of a concentration meter, and an inspection method for the same.SOLUTION: A processing liquid supply device 1 includes a tank T that stores a processing liquid L, a supply route S that supplies the processing liquid L from the tank T to a processing device 100, a heating portion including heaters H1 to H4 that heats the processing liquid L, a thermometer TM that measures the temperature of the processing liquid L, a densitometer D that measures the concentration of the processing liquid L, and a control device E having an inspection portion 23 that inspects the densitometer D. The inspection portion 23 includes a temperature setting portion 231 that sets a boiling point temperature at a predetermined concentration as a predetermined temperature on the basis of the atmospheric pressure at the location where the processing liquid supply device 1 is installed and a preset vapor pressure curve of the processing liquid, a heating control portion 232 that heats the processing liquid with the heating portion to set the temperature at the target temperature which is within a predetermined range on the basis of a predetermined temperature, and a determination portion 233 that determines whether the concentration of the processing liquid that has reached the target temperature measured by the densitometer is a target concentration that is within a predetermined range based on the predetermined concentration.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a processing liquid supplying apparatus, a substrate processing apparatus, and a method for inspecting the processing liquid supplying apparatus. [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] However, in single-wafer 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 immersion. However, in the single-wafer processing, the processing liquid supplied to the substrate must be supplied so that parameters that affect the process performance are always constant.

[0005] In addition, in both batch and single-wafer processing apparatuses, it is essential to recover and reuse the liquid used in the processing from the viewpoint of reducing processing costs. Even in such a case of reuse, in the batch processing apparatus, parameters can be checked and adjusted during the long processing time during which the substrate is immersed in the processing tank. However, in the single-wafer processing apparatus, fluctuations in the parameters of the processing liquid supplied to the substrate appear in the product as variations in processing performance over a short period of time. For this reason, it is necessary to continuously supply to the substrate a processing liquid, including the recovered processing liquid, that has been adjusted to an optimal concentration and temperature. In other words, in the single-wafer processing apparatus, it is necessary to always keep fluctuations in the concentration and temperature of the processing liquid used within a very small range.

[0006] Here, it is the recovered liquid that has a large effect on the fluctuations in the temperature of the processing liquid. In other words, since the processing liquid used in 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 level while supplying it. For example, the amount of recovered liquid generated varies depending on the timing of processing. In particular, when processing is performed in multiple processing chambers at the same time, the recovered amount also varies greatly over time. In a configuration in which the recovered liquid is collected in a tank and heated for reuse, the inflow of recovered liquid causes large temperature fluctuations.

[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 input, heating is always performed to maintain the liquid in the recovery tank at a high temperature, so the water in the recovery liquid evaporates over time and the concentration of the recovery liquid increases. Since no substrate processing is performed while no recovery liquid is being input, there is no decrease in the amount of liquid in the supply tank that sends 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 keeping the temperature constant 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 is provided with two tanks that supply the recovered processing liquid to a processing section, and substrate processing is performed while alternately switching the connection between the processing section and the tanks. Each tank is provided with a concentration meter, and deterioration of the processing liquid is judged based on the measurement value of this concentration meter. For tanks in which deterioration has occurred, the processing liquid is replaced. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] JP 2007-273791 A Summary of the Invention [Problem to be solved by the invention]

[0011] In single-wafer processing equipment, fine patterns have When etching a wafer, the etching rate varies depending on the concentration and temperature of the processing solution, which can cause product quality problems. temperature These parameters have a large effect on processing performance. In particular, if it is not possible to determine whether the concentration meter is working properly, it can lead to product defects.

[0012] More specifically, in order to supply the processing liquid at a temperature slightly lower than the boiling point and with a constant and stable concentration, it is necessary to control both the amount of dilution water added and the liquid temperature generated by the heater based on the concentration value measured by the concentration meter. If the concentration value measured by the concentration meter is deviated due to dirt or the like, the concentration will no longer be correct, and products processed with this processing liquid will not be able to undergo the specified etching process. However, currently, there is no function in substrate processing equipment to inspect the function of the concentration meter.

[0013] An object of the embodiments of the present invention is to provide a processing liquid supplying apparatus, a substrate processing apparatus, and a method for testing a processing liquid supplying apparatus that are capable of testing the function of a concentration meter. [Means for solving the problem]

[0014] An embodiment of the present invention is a processing liquid supplying device that supplies a processing liquid to a processing device that processes a substrate with the processing liquid, the processing liquid supplying device having a tank for storing the processing liquid, a supply path for supplying the processing liquid from the tank to the processing device, a heating unit for heating the processing liquid, a thermometer for measuring the temperature of the processing liquid, a concentration meter for measuring the concentration of the processing liquid, and an inspection unit for inspecting the concentration meter, the inspection unit having a temperature setting unit that sets a boiling point temperature at which a predetermined concentration is achieved as a predetermined temperature based on the atmospheric pressure at a location where the processing liquid supplying device is installed and a predetermined vapor pressure curve of the processing liquid, a heating control unit that heats the processing liquid with the heating unit to a target temperature that is within a predetermined range based on the predetermined temperature, and a judgment unit that judges whether the concentration of the processing liquid at the target temperature measured by the concentration meter is a target concentration that is within a predetermined range based on the predetermined concentration.

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

[0016] An embodiment of the present invention is a method for inspecting a processing liquid supplying device, comprising the steps of: a boiling point temperature at which a predetermined concentration is achieved is set as a predetermined temperature based on the atmospheric pressure at a location where a processing liquid supplying device that supplies the processing liquid to a processing device that processes a substrate with the processing liquid is installed and a preset vapor pressure curve of the processing liquid; heating the treatment liquid by a heating unit so that a temperature of the treatment liquid measured by a thermometer becomes a target temperature within a predetermined range based on the predetermined temperature; When the temperature of the treatment liquid reaches the target temperature, it is determined whether the concentration of the treatment liquid measured by a concentration meter that measures the concentration of the treatment liquid is within a predetermined range based on the predetermined concentration as a reference. This checks whether the densitometer is functioning normally. Effect of the Invention

[0017] The embodiments of the present invention can provide a processing liquid supplying apparatus, a substrate processing apparatus, and a method for testing a processing liquid supplying apparatus that can test the function of a concentration meter. [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] 4 is a graph showing the progress of a vapor pressure curve of a processing liquid in the processing liquid supplying device according to the embodiment. [Diagram 3] 5 is a flowchart showing a procedure for inspecting a concentration meter by the treatment liquid supplying device according to the embodiment. [Figure 4] 5 is a graph showing concentration control in the treatment liquid supplying device according to the embodiment. 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 the processing liquid L to a processing apparatus 100 that processes a substrate W with the processing liquid L by passing the processing liquid L through a plurality of 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 plurality of 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 target concentration within a predetermined range based on a predetermined concentration (set 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] In the processing liquid supplying apparatus 1 of the embodiment, the air pressure at the location where the processing liquid supplying apparatus 1 is placed is measured by the barometer B, and the boiling point temperature at which the processing liquid L has a predetermined concentration is obtained from a vapor pressure curve of the processing liquid L that has been obtained in advance. The boiling point temperature thus obtained is set as a predetermined temperature (set temperature), and the processing liquid L is heated. The concentration of the processing liquid L that has reached a target temperature within a predetermined range based on the predetermined temperature is measured, and it is confirmed whether the measured concentration is the target concentration. This allows a judgment to be made as to whether the concentration meter D is normal or abnormal.

[0021] If the concentration of the processing liquid L is lower than the target concentration, the processing liquid L will boil at the target temperature and settle at the target concentration if the target temperature is set based on the obtained boiling point temperature. Therefore, by measuring the concentration of the processing liquid L at the target temperature with the concentration meter D and comparing it with the target concentration, it is possible to confirm whether the measured concentration value is correct. However, if the concentration of the processing liquid L is higher than the target concentration, the processing liquid L will not boil and the concentration will remain higher than the target concentration even when the target temperature is reached. In this case, the processing liquid L is diluted once so that the concentration is equal to or lower than the target concentration, and then heated again and the concentration value is measured, thereby making it possible to determine whether the concentration meter D is normal.

[0022] In this way, the processing liquid supplying device 1 has a self-check function for the concentration meter D. If it is within the allowable range, i.e., if it is normal, it continues to use the concentration meter D. If it is outside the allowable range, i.e., if it is abnormal, it outputs an alarm, cleans the concentration meter D, stops the supply of the processing liquid L, or takes other appropriate action.

[0023] [Processing device] The processing apparatus 100 is, for example, a single-wafer etching apparatus that supplies a processing liquid L to a rotating substrate W to remove an unnecessary film formed on the processing surface of the substrate W and leave a circuit pattern. 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) as a chemical liquid (hereinafter referred to as a phosphoric acid solution) 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.

[0024] 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.

[0025] 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.

[0026] 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 rotating 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.

[0027] [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.

[0028] 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.

[0029] 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.

[0030] (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.

[0031] 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 thermometer TM is provided downstream of the heater H1, and the output of the heater H1 is adjusted based on feedback from the thermometer TM. The thermometer TM 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.

[0032] The filter F is provided downstream of the heater H1 and serves to remove impurities from the processing liquid L flowing through the supply pipe S1. The valve V1a is provided downstream of the filter F and serves to switch between supplying and not supplying the processing liquid L to the processing apparatus 100.

[0033] 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.

[0034] 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.

[0035] (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.

[0036] 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 the buffer tank T3, the upper part (return) of the recovery tank T2, or the common flow path C described below is defined as the upstream side, and the opposite side is defined as the downstream side. A thermometer TM is provided downstream of the heater H2, and the output of the heater H2 is adjusted based on feedback from the thermometer TM. The thermometer TM is, for example, a thermistor.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] (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.

[0041] 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. P3 The processing liquid L discharged from the heater H3 is heated to a predetermined target temperature. In this embodiment, the bottom side of the buffer tank T3 in the flow from the bottom of the buffer tank T3 toward 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 thermometer TM is provided downstream of the heater H3, and the output of the heater H3 is adjusted based on feedback from the thermometer TM. The thermometer TM is, for example, a thermistor.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] (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.

[0047] 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 defined as the upstream side, and the opposite side is defined as the downstream side. A thermometer TM is provided downstream of the heater H4, and the output of the heater H4 is adjusted based on feedback from the thermometer TM. The thermometer TM is, for example, a thermistor.

[0048] 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.

[0049] By closing the valves V4a, V4c, and V4d and 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 fixed 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.

[0050] 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.

[0051] 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.

[0052] (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.

[0053] (Common flow path) The common flow path C is a common path through which the processing liquid L of the 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 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.

[0054] (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.

[0055] A cleaning liquid supply circuit K that cleans the inside of the concentration meter D is connected to the common flow path C. The cleaning liquid supply circuit K has a pipe and a valve Vk1 that supplies the dilution liquid from the dilution unit I to the common flow path C to clean the inside of the concentration meter D. In addition, a pipe that discharges the dilution liquid that has been supplied from the cleaning liquid supply circuit K and used to clean the concentration meter D to a discharge path Z is directly connected to the common flow path C, and a valve Vk2 is provided on this pipe.

[0056] (Barometer) The barometer B is installed in a processing chamber, which is a housing that houses the processing liquid supplying apparatus 1, in an associated area in which the control device E and the like are arranged. However, the installation location of the barometer B is not limited to this. In other words, as long as it is possible to measure the air pressure at the location where the processing liquid supplying apparatus 1 is installed, the barometer B may be installed outside the processing liquid supplying apparatus 1 or inside the room or floor where the processing liquid supplying apparatus 1 is installed.

[0057] (Control device) The control device E controls each part of the substrate processing apparatus SS. To realize various functions of the substrate processing apparatus SS, the control device E has a processor that executes programs, a memory that stores various information such as programs and operating conditions, and a drive circuit that drives each element. The control device E is connected to an input unit Ei that inputs information and an output unit Eо that outputs information. The input unit Ei is an input device such as a touch panel, keyboard, mouse, switch, etc. The output unit Eо is an output device such as a display, lamp, speaker, buzzer, etc.

[0058] The control device E includes a substrate processing control section 21, a concentration control section 22, an inspection section 23, a cleaning processing section 24, and a memory section 25. The substrate processing control section 21 controls each section of the processing device 100 and the processing liquid supplying device 1 to perform processing of 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.

[0059] 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. The set concentration is, for example, 87.7%. In this concentration control, as described above, the temperature of the treatment liquid L is also controlled to become a predetermined target value (target temperature). 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 amount of heating 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 (target concentration, target temperature) and the amount of change in the measured value, and controls the heating unit H and the dilution unit I. In addition, when calculating the difference between the measured value and the target value, the set concentration and the set temperature are used, but it is not necessary to control them to exactly match these set concentrations and set temperatures, and it is sufficient to control them to fall within the range of the target concentration and the target temperature.

[0060] 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.

[0061] By setting the time interval, the measurement time for all tanks T can be the same, or the measurement time for each tank T can be different. For example, the measurement time for a specific tank T can be made longer. However, when the measurement time is the same, it is preferable to increase the measurement frequency rather than ensuring a long measurement time for each measurement. This makes it possible to measure a large number of tanks T within a certain period of time and adjust the concentration of each tank, making it easier for the entire tank to converge to the target value.

[0062] The inspection unit 23 includes a temperature setting unit 231, a heating control unit 232, and a judgment unit 233. The temperature setting unit 231 sets the boiling point temperature at which a predetermined concentration is achieved as a predetermined temperature (set temperature) based on the atmospheric pressure at the location where the treatment liquid supplying device 1 is installed and a preset vapor pressure curve of the treatment liquid L. The atmospheric pressure (atmospheric pressure at the location where the treatment liquid supplying device 1 is installed) is acquired from a barometer B connected to the control device E. The heating control unit 232 heats the treatment liquid L by the heating unit H to a target temperature within a predetermined range based on the set temperature. The judgment unit 233 judges whether the concentration of the treatment liquid L at the target temperature measured by the concentration meter D is within a predetermined range based on the predetermined concentration (set concentration), that is, whether it is the target concentration.

[0063] When the determination unit 233 determines that the concentration is not the target concentration but is higher than the target concentration, the heating control unit 232 supplies dilution liquid from the dilution unit I to the treatment liquid L so that the treatment liquid L has a concentration lower than the target concentration and a temperature lower than the target temperature, and then heats the treatment liquid L again to the target temperature using the heating unit H. The determination unit 233 again determines whether the concentration of the treatment liquid L that has become the target concentration measured by the concentration meter D is the target concentration or not.

[0064] The output unit Eо outputs information to notify the concentration when the determination unit 233 determines that the concentration is not the target concentration or is lower than the target concentration, or when the concentration is higher than the target concentration and is again determined to not be the target concentration due to reheating after dilution. For example, the display of the output unit Eо displays information indicating that the concentration meter D is not normal, or a lamp lights up or blinks to notify the concentration meter D is not normal. In addition, the speaker of the output unit Eо outputs a sound to notify the concentration meter D is not normal, or a buzzer alarm sounds to notify the concentration meter D is not normal.

[0065] The vapor pressure curve can be obtained by measuring the temperature and air pressure when the processing liquid L is boiled to a target concentration at the location where the processing liquid supplying apparatus 1 is installed, and measuring the boiling point temperature when the air pressure changes between low and high pressure. Since there may be a difference between the air pressure in the tank T and the atmospheric pressure due to the influence of the configuration of the processing liquid supplying apparatus 1, it is desirable to perform evaluation with the same device configuration. The vapor pressure curve may be set based on a calculation performed by the control device E, or may be set based on an input from the input unit Ei.

[0066] FIG. 2 shows an example of a vapor pressure curve of the processing liquid L when it is heated in the atmosphere and boils. In FIG. 2, the vapor pressure curve VPCi of the initial concentration is shown by a dotted line, the vapor pressure curve VPCt of the target concentration is shown by a solid line, and the vapor pressure curve VPCh of the liquid having a higher concentration than the target concentration is shown by a dashed line. Note that FIG. 2 shows the behavior of the concentration changing by refilling the new liquid tank T4 with a new liquid having a lower concentration than the target concentration and then heating it to boiling, as described later. That is, this is an example in which the concentration is adjusted using the heating path of the new liquid tank T4 of the processing liquid supplying device 1 shown in FIG. 1. However, the behavior of the vapor pressure curves VPCi, VPCt, VPCh, temperature, and concentration changes shown here are common to the general behavior of the processing liquid L, and therefore will be described with reference to FIG. 2.

[0067] The boiling point of the liquid moves along the vapor pressure curve when the atmospheric pressure changes. Therefore, when the device is installed at a high altitude or when a low pressure passes due to a typhoon, the boiling point decreases. That is, as shown in the vapor pressure curve VPCi in FIG. 2, when the atmospheric pressure Pa is high, the boiling point Bpa is high, and when the atmospheric pressure Pb is low, the boiling point Bpb is low. In this way, the boiling point changes depending on the atmospheric pressure. This means that when a processing liquid L of a certain concentration is heated, boiling starts earlier when the atmospheric pressure is low, and boiling starts later when the atmospheric pressure is high. The boiling point of the processing liquid L when it boils is determined by the concentration of the processing liquid L and the atmospheric pressure, so even if the target temperature is set in advance, the concentration of the processing liquid L changes due to the change in atmospheric pressure and is not constant. In other words, when the boiling point changes, the boiling temperature changes and the amount of water evaporated changes, so even if the processing liquid L is kept at the same temperature (target temperature), the concentration of the boiled processing liquid L changes.

[0068] The inventors focused on such vapor pressure curves in order to obtain an effective method for determining whether or not the concentration meter D is normal. After extensive investigation, the inventors found the following method. That is, for the processing liquid L to be used, a vapor pressure curve VPCt for a set concentration is obtained. Furthermore, a boiling point temperature corresponding to a change in atmospheric pressure (change in vapor pressure) is obtained from the vapor pressure curve VPCt. For example, a boiling point temperature Ta for atmospheric pressure Pa and a boiling point temperature Tb for atmospheric pressure Pb are obtained. Furthermore, the processing liquid L is heated and the concentration of the processing liquid L at the boiling point temperatures Ta and Tb is measured with the concentration meter D, and it is determined whether or not the measured value is a target concentration within a predetermined range based on the set concentration. In this way, it is possible to check whether or not the concentration meter D is normal.

[0069] When the determination unit 233 determines that the concentration is not the target concentration, the cleaning unit 24 performs cleaning of the concentration meter D. The cleaning unit 24 controls the valves Vk1 and Vk2 of the cleaning liquid supply circuit K to pass the dilution liquid through the concentration meter D to perform cleaning. That is, by opening the valves Vk1 and Vk2, the cleaning liquid supply circuit K is supplied with the dilution liquid to the common flow path C to clean the concentration meter D and to discharge the dilution liquid into the discharge path Z. Also, when measuring the concentration of the treatment liquid L in each tank T, an operation of replacing the treatment liquid L in the common flow path C is performed. That is, the treatment liquid L from the tank T whose concentration is to be measured is passed through the common flow path C for a certain period of time, and then the concentration is measured. In this way, the first certain period of time of passing the treatment liquid L from each tank T to the concentration meter D is a process of replacing the previous treatment liquid L, so that the treatment liquid L is directly passed from the common flow path C to the discharge path Z without returning it to the tank T by opening the valve Vk2. In this case, a configuration may be adopted in which the liquid can be drained without passing through the tank T by, for example, providing a separate flow path that allows the liquid to flow directly from the common flow path C to the discharge path Z.

[0070] The storage unit 25 is configured as a memory and stores a target concentration, a target temperature, a time interval, a vapor pressure curve, and the like. The operator can input desired values ​​for the target concentration, the target temperature, and the time interval through the input unit Ei. 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 a large fluctuation 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 substrate W. The target concentration and the target temperature may be set by a combination of a predetermined concentration, a predetermined temperature, and an allowable predetermined range.

[0071] [Operation] The operation of the substrate processing apparatus SS of the present embodiment as described above will be described with reference to Figures 3 and 4 in addition to Figures 1 and 2. Note that a substrate processing method for processing a substrate W in the following procedure is also one aspect of this embodiment.

[0072] (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.

[0073] 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.

[0074] (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.

[0075] 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.

[0076] 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.

[0077] 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.

[0078] (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 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 by sequentially switching at predetermined time intervals between opening the valves corresponding to one of the sets 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.

[0079] When measuring the concentration of the processing liquid L in each of the tanks T1 to T4, as described above, the processing liquid L from any of the tanks T whose concentration is to be measured is caused to flow into the common flow path C for a certain period of time to replace the previous processing liquid L, and then the concentration is measured. This makes it possible to selectively cause the processing liquid L from the tanks T1 to T4 to flow into the common flow path C, so that the concentration of each of the tanks T1 to T4 can be measured at predetermined time intervals using one concentration meter D.

[0080] 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, and if dilution is required, the valve V5 of the piping of the dilution section I to the corresponding tank T1-T4 is opened to add a predetermined amount of pure water.

[0081] As described above, the concentration of the processing liquid L in each tank T1 to T4 can be adjusted using the concentration meter D. The purpose of this concentration adjustment is to stabilize the concentration of the processing liquid L at a target concentration in the supply tank T1 that supplies the processing liquid L to the processing device 100. Among the tanks T1 to T4, the temperature and concentration of the processing liquid L in the recovery tank T2 fluctuate relatively greatly due to the inflow of the recovered processing liquid L. For this reason, at the timing of sending the processing liquid to the buffer tank T3, the processing liquid L in the recovery tank T2 may not be adjusted to the target concentration. Therefore, even if the processing liquid L flows from the recovery tank T2 into the buffer tank T3, the processing liquid L is sent out so that the fluctuations in temperature and concentration are small when it is sent to the supply tank T1. For this reason, it is necessary to control the concentration based on the concentration measurement by the concentration meter D. If such control can be performed efficiently and in a short time, it may be possible to omit adjusting the tanks T1 to T4 in stages.

[0082] Furthermore, when new liquid tank T4 is replenished with new liquid at room temperature, the processing liquid L, which had been adjusted to the target concentration and target temperature up until that point, changes due to the replenished new liquid. The temperature changes to a temperature lower than the target temperature, and the concentration changes to the concentration of the replenished new liquid. Regarding the temperature of the processing liquid L, the temperature of the processing liquid L in the new liquid tank T4 can be restored by setting the outlet temperature of heater H4 to a temperature that brings the temperature of the processing liquid L to the target temperature. On the other hand, regarding the concentration, the possible adjustment methods change depending on the concentration of the processing liquid L being replenished.

[0083] The processing liquid L used to process the substrate W is often adjusted in concentration by mixing a high-concentration chemical with pure water. However, for processing liquid L such as phosphoric acid, which has the highest etching rate when used at the boiling point of the solution, adjustment is required near the boiling point, so the concentration is adjusted by boiling the processing liquid L at room temperature to increase it. For such processing liquid L, the main method is to adjust the concentration by heating, from a low concentration to a high concentration.

[0084] On the other hand, once the temperature of the processing liquid L is adjusted by heating and becomes higher than the target concentration, the concentration of the processing liquid L will not decrease even if the temperature of the processing liquid L is lowered by heat radiation from the surface of the new liquid tank T4. To decrease the concentration, it is necessary to decrease the overall concentration of the processing liquid L in the new liquid tank T4 by adding dilution water or mixing new liquid with a low concentration. In this case, the temperature will also decrease, so in order to simultaneously adjust both the concentration and the temperature to the target concentration and target temperature, the amount of addition is calculated from the concentration and temperature of the mixed liquid and added. However, it is difficult to find a solution that adjusts the concentration to the target concentration and the temperature to the target temperature at the same time with the amount of addition. Therefore, dilution water or new liquid that adjusts the concentration to the target concentration is added, the temperature is temporarily lowered, and then the temperature is adjusted to the target value by heating.

[0085] (Densitometer test) Next, the procedure for inspecting the concentration meter D will be described with reference to the flow chart of FIG. 3. First, the inspection unit 23 of the control device E acquires the atmospheric pressure measured by the barometer B at the location where the treatment liquid supply device 1 is installed (step S01). The temperature setting unit 231 sets the boiling point temperature at which the concentration is set as a predetermined temperature (set temperature) based on the acquired atmospheric pressure and a preset vapor pressure curve (vapor pressure curve of the set concentration) of the treatment liquid L (step S02). The heating control unit 232 heats the treatment liquid L by the heating unit H (step S03). When the treatment liquid L reaches the target temperature based on the measurement value of the thermometer TM (YES in step S04), the concentration of the treatment liquid L is measured by flowing the treatment liquid L through the concentration meter D (step S05). Note that, even in the concentration measurement for inspecting the concentration meter D, the previous treatment liquid L is replaced by passing the treatment liquid L from the tank T through the concentration meter D for a certain period of time in advance.

[0086] The determination unit 233 determines whether the concentration of the processing liquid L measured by the concentration meter D is the target concentration or not (step S06). If it is the target concentration (YES in step S07), the inspection is ended and processing of the substrate W is continued. If it is not the target concentration (NO in step S07) or is lower than the target concentration (NO in step S08), the output unit Eo outputs information notifying this (step S15).

[0087] If the concentration is not the target concentration (NO in step S07) but is higher than the target concentration (YES in step S08), a diluting solution is added to reduce the concentration value below the target concentration and the temperature below the target temperature (step S09). Then, the heating control unit 232 causes the heating unit H to heat the processing liquid L again (step S10), and if the target temperature is reached (YES in step S11), the concentration of the processing liquid L is measured by the concentration meter D (step S12). The determination unit 233 re-determines whether the concentration of the processing liquid L measured by the concentration meter D is the target concentration or not (step S13). If the concentration is the target concentration (YES in step S14), the inspection is ended and the processing of the substrate W is continued. If the concentration is not the target concentration (NO in step S14), the output unit Eo outputs information notifying this (step S15).

[0088] Incidentally, by measuring the atmospheric pressure as described above and calculating the change in boiling point temperature, and raising the temperature of the processing liquid L in the tank T to this boiling point temperature, it is also possible to control the concentration of the processing liquid L to the target concentration. In this way, it is preferable to adjust the concentration and temperature to the target concentration and target temperature in the new liquid tank T4, which does not replenish the other tanks T1 to T3, until the processing liquid L is ready. After refilling with new low-concentration liquid, the tank is heated to raise the temperature to the target temperature at which the target concentration is achieved, thereby making it possible to adjust the concentration to the target concentration.

[0089] FIG. 4 shows the change over time in the temperature of the processing liquid L in the new liquid tank T4 (solid line) and the outlet temperature of the heater H4 of the processing liquid L heated by the heater H4 (dotted line). As shown by the solid line in FIG. 4, when the processing liquid L in the new liquid tank T4, whose concentration and temperature have decreased, is heated by the heating section H of the circulation path, that is, the in-line heater H4, the concentration and temperature gradually approach the target concentration and target temperature due to the processing liquid L returned to the new liquid tank T4. When heating by the in-line heater H4, as shown by the dotted line in FIG. 4, the outlet temperature of the heater H4 is set to a temperature slightly higher than the set temperature. This allows the temperature of the processing liquid L in the new liquid tank T4 to increase faster when the processing liquid L heated by the heater H4 is returned to the new liquid tank T4. In other words, the temperature of the processing liquid L increases over time, and the temperature and concentration of the processing liquid L in the new liquid tank T4 can be brought closer to the target temperature and target concentration. It is preferable that the value be set so that the amount of dilution water added using the concentration meter D can be controlled to maintain the temperature of the new solution tank T4 at the target temperature.

[0090] In the in-line heater H4, the processing liquid L boils and is returned to the new liquid tank T4, and the generated water vapor is released from the surface of the new liquid tank T4. The boiling temperature at this time is the boiling point temperature changed by atmospheric pressure, and the concentration is the target concentration. Setting the temperature a little higher will allow the processing liquid L in the new liquid tank T4, which has a lower concentration, to be mixed and quickly approach the target concentration. Due to the heating of the circulation path, the temperature of the processing liquid L in the new liquid tank T4 gradually rises and approaches the target temperature. In that case, the difference between the temperature of the processing liquid L sucked into the circulation path and the set temperature of the heater H4 becomes small, and the amount of heating by the heater H4 becomes small.

[0091] In this state, boiling caused by heater H4 becomes very slight, and the outlet temperature of heater H4 becomes stable. Even if the processing liquid L in this state is measured by concentration meter D, the measured concentration value becomes stable. This concentration value is the concentration at the preset boiling point, which is the target concentration. Therefore, as described above, it is possible to check whether concentration meter D is functioning normally, depending on whether the concentration value of concentration meter D indicates the target concentration.

[0092] This check can be performed after the boiling has subsided, allowing for more stable measurements, so there is a possibility that the concentration meter D will show a value slightly higher than the target concentration. In this case, the concentration of the processing liquid L is measured using a different method, the difference from the target concentration is examined, and this difference is used as an offset value from the next time onwards, making it possible to more accurately determine whether the concentration meter D is normal or not. Another method, for example, is to check the concentration by sampling the processing liquid L and measuring its specific gravity.

[0093] If it is possible to determine whether or not the concentration meter D is functioning normally by heating and boiling the processing liquid L in the new liquid tank T4, it is possible to eliminate the risk of using the concentration meter D to control the concentrations of the other tanks T1-T3. Furthermore, since the processing liquid L is replenished in the new liquid tank T4 in accordance with the number of substrates processed in the processing apparatus 100, it becomes possible to check the function of the concentration meter D at regular processing intervals. If the processing frequency is high, the setting can be changed to a regular time interval.

[0094] If it is determined that the concentration meter D is not normal, an alarm is output as described above. Furthermore, it is possible to perform the following processing. For example, since the concentration meter D was normal when the new solution was last replenished, it is determined that the level is not at a level that requires immediate shutdown of the apparatus, and the processing of substrates W can be continued until the supply tank T1 is used up.

[0095] During this time, it may be checked again whether or not the concentration meter D can be reset by cleaning. To do this, the cleaning processing unit 24 cleans the concentration meter D, and if the concentration value falls within the allowable range, the concentration meter D becomes usable. Since the concentration value of the concentration meter D often varies from the normal value due to contamination caused by the processing liquid L, etc., resetting the concentration meter D by cleaning is effective. If the measured concentration value is outside the allowable range even after cleaning, the output unit Eo may output an alarm so that the operator can determine this. Furthermore, if the concentration value is outside the allowable range and the deviation is very large, the processing liquid supplying device 1 may be stopped.

[0096] More specifically, a process of etching a nitride film on a wafer, which is a substrate W, by the processing liquid supplying device 1 supplying a high-temperature processing liquid L containing a phosphoric acid solution to the processing device 100 will be described. Since phosphoric acid solution has the highest etching rate (maximum value) of boiling point liquids, processing is performed at near the boiling point. However, processing with a boiling liquid may damage the wafer, so in practice it is used at a temperature slightly lower than the boiling point. Even in this case, in order to obtain a high etching rate, it is effective to keep the phosphoric acid concentration in the processing liquid L high.

[0097] The temperature at which the treatment liquid supplying device 1 can stably supply the treatment liquid L is generally about 160°C, and the concentration of the treatment liquid L containing a phosphoric acid solution is about 87.7%. Therefore, in the treatment liquid supplying device 1, new liquid that is replenished at about 86% is heated to boiling, thereby evaporating the water and increasing the concentration.

[0098] In this case, if the entire processing liquid L in the tank T is heated, boiling will begin in the entire tank T, and it is dangerous and difficult to continue increasing the concentration. For example, when increasing the concentration by heating the entire tank T, a large amount of processing liquid L may boil all at once, which may cause phenomena such as fluctuations in the liquid level in the tank T, steam leakage due to an increase in the internal pressure of the tank T caused by the sudden increase in water vapor, and inflow of the processing liquid L into the exhaust pipe. For this reason, the processing liquid L sucked from the tank T by the pump P is usually heated and boiled in the in-line heating section H and returned to the tank T as described above, gradually increasing the concentration and temperature of the processing liquid L in the tank T. The boiling of the processing liquid L occurs in the piping that returns it to the tank T after heating, and when the processing liquid L returns to the tank T, the generated water vapor is released into the atmosphere from the surface of the tank T and exhausted outside the device.

[0099] In this way, the concentration of the processing liquid L in the tank T is set to 87.7%, but simply controlling the outlet temperature of the in-line heating section H to 160°C does not always ensure that the concentration in the tank T is the same 87.7%. This is because the boiling temperature of the processing liquid L changes depending on the air pressure at the outlet of the heating section H.

[0100] The change in boiling point due to air pressure when tank T is replenished with new low-concentration liquid and the concentration is controlled to a target value by heating and boiling can be represented by a vapor pressure curve similar to that shown in Figure 2 above. When the air pressure is high (Pa), a predetermined temperature is set for the boiling point temperature Ta of the target concentration. As the processing liquid L is heated, the concentration of the processing liquid L, which has decreased due to the replenishment of new liquid, begins to boil at a temperature lower than the set predetermined temperature, and the concentration gradually increases. When the temperature of the processing liquid L eventually approaches the set temperature, the heating of the heating section H is weakened, and the temperature of tank T becomes the target temperature. At this point, the concentration of the processing liquid L in tank T becomes the target concentration.

[0101] However, when the processing liquid L is heated, as the air pressure increases (Pb → Pa), the boiling temperature increases (Tb → T a). In this way, the temperature at which the processing liquid L boils, that is, at which it reaches saturated vapor pressure, changes with the air pressure. For this reason, the concentration of the processing liquid L when it boils also changes. Then, when the air pressure is low at Pb, if the set temperature is set to Ta, the processing liquid L in tank T will rise to temperature Ta while boiling. In other words, the vapor pressure curve of the processing liquid L will be a vapor pressure curve with a concentration value higher than the target concentration. Therefore, the state of the processing liquid L at point α will have a concentration value higher than the target concentration.

[0102] To prevent this, if a vapor pressure curve of the target concentration is obtained in advance and the set temperature is corrected according to the atmospheric pressure at the time of heating, the treatment liquid L in the tank T can be adjusted to the target concentration only by controlling the temperature by heating. For example, the boiling temperature of the treatment liquid L containing a phosphoric acid solution with a concentration of 87.7% due to changes in atmospheric pressure is previously investigated, and the atmospheric pressure of the atmosphere in which the treatment liquid supplying device 1 is placed, i.e., the atmospheric pressure of the installation location is measured, so that the treatment liquid L with a low concentration is heated to boil and the temperature at which the concentration of the treatment liquid L becomes 87.7% can be known. In the treatment liquid supplying device 1, this temperature is set as the set temperature, and if the treatment liquid L in the tank T is heated and the target temperature is reached, the treatment liquid L with the target concentration of 87.7% is obtained. Thereafter, the temperature and concentration can be maintained. In this way, by controlling the concentration of the treatment liquid L in the tank T, the concentration in the tank T can be maintained constant.

[0103] Furthermore, as described above, if the concentration value indicated by the concentration meter D when the temperature of the processing liquid L in the tank T reaches the target temperature is 87.7%, it can be determined that the concentration meter D is measuring normally. In other words, depending on whether the measured value of the concentration meter D is within the allowable value of the set concentration, including measurement error, etc., it can be checked whether the concentration meter D is functioning normally, and it can be determined whether the concentration control using the concentration meter D thereafter is possible.

[0104] [effect] (1) This embodiment is 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 tank T for storing the processing liquid L, a supply path S for supplying the processing liquid L from the tank T to the processing device 100, a heating section H for heating the processing liquid L, a thermometer TM for measuring the temperature of the processing liquid L, a concentration meter D for measuring the concentration of the processing liquid L, and an inspection section 23 for inspecting the concentration meter D.

[0105] The inspection unit 23 includes a temperature setting unit 231 that sets the boiling point temperature at which a predetermined concentration is achieved as a predetermined temperature based on the atmospheric pressure at the location where the treatment liquid supplying device 1 is installed and a preset vapor pressure curve of the treatment liquid L, a heating control unit 232 that heats the treatment liquid L using the heating unit H to a target temperature that is within a predetermined range based on the predetermined temperature, and a judgment unit 233 that judges whether the concentration of the treatment liquid L at the target temperature measured by the concentration meter D is the target concentration that is within a predetermined range based on the predetermined concentration.

[0106] In addition, the inspection method for the processing liquid supplying apparatus 1 of this embodiment sets the boiling point temperature at which a predetermined concentration is achieved as a set temperature based on the atmospheric pressure at a location where the processing liquid supplying apparatus 1 that supplies the processing liquid L is installed in the processing apparatus 100 that processes the substrate W with the processing liquid L and a preset vapor pressure curve of the processing liquid L, heats the processing liquid L by the heating section H so that the temperature of the processing liquid L measured by the thermometer TM becomes a target temperature within a predetermined range based on the predetermined temperature, and when the processing liquid L reaches the target temperature, determines whether the concentration of the processing liquid L measured by the concentration meter D that measures the concentration of the processing liquid L is the target concentration within a predetermined range based on the predetermined concentration.

[0107] In this way, the concentration meter D can be checked for normality by heating the processing liquid L and comparing the concentration, so that the occurrence of product defects caused by processing with a processing liquid L whose concentration deviates from the normal value can be reduced. If there is a problem with the function of the concentration meter D, the processing can be stopped, so that product defects can be prevented in advance. Heating of the replenished processing liquid L occurs at any time during the supply process of the processing liquid L, and the concentration meter D can be inspected each time, so that the waiting time for processing due to the cleaning and calibration of the concentration meter D can be minimized. Furthermore, unlike the method of continuing to use the concentration meter D by using an alternative means when there is an abnormality such as a breakdown in the concentration meter D that clearly makes it impossible to continue using it, the concentration meter D can be inspected by checking for deviations from the normal value, so that processing with high accuracy is possible. For example, even changes in the measured value due to dirt can be inspected.

[0108] (2) When the determination unit 233 determines that the concentration is not the target concentration but is higher than the target concentration, the heating control unit 232 dilutes the treatment liquid L to a concentration lower than the target concentration and a temperature lower than the target temperature, and then heats the treatment liquid L again using the heating unit H to the target temperature; The determination unit 233 determines again whether the concentration of the treatment liquid L that has reached the target temperature and is measured by the concentration meter D is the target concentration.

[0109] When the determination unit 233 again determines that the concentration is not the target concentration, an output unit E0 is provided for outputting information notifying the determination. Therefore, the operator can know the abnormality of the concentration meter D and can determine whether or not to continue the process.

[0110] (3) A cleaning unit 24 is provided which performs a cleaning process on the concentration meter D when the determination unit 233 determines that the concentration is not the target concentration. Therefore, when there is a deviation in the measurement value of the concentration meter D, the cleaning process is performed to restore the function, thereby reducing the occurrence of product defects.

[0111] (4) The processing liquid supplying apparatus 1 has a barometer B for measuring atmospheric pressure. Therefore, the atmospheric pressure at the location where the processing liquid supplying apparatus 1 is installed can be accurately measured.

[0112] (5) It has a dilution section I which dilutes the processing liquid L with a diluting liquid, and the tank T includes a supply tank T1 which supplies the processing liquid L to the processing device 100, a recovery tank T2 which recovers the processing liquid L which has been processed in the processing device 100, and a new liquid tank T4 which supplies new processing liquid L, and the control device E has a concentration control section 22 which adjusts the concentration of the processing liquid L in the supply tank T1, the recovery tank T2 and the new liquid tank T4 by controlling the heating section H and the dilution section I based on the concentration measured by the concentration meter D when the judgment section 233 judges that it is within a predetermined range.

[0113] Therefore, by checking the function of the concentration meter D with the processing liquid L in any one of the multiple tanks T, the reliability of the control of the other tanks T that performs concentration control using the concentration meter D is increased.

[0114] [Variations] The above embodiment can also be modified as follows. (1) The tolerance range for the set concentration may be set in two stages, and if the concentration exceeds the tolerance range of the first stage, the treatment liquid L is washed away, and if the concentration exceeds the tolerance range of the second stage, the supply of the treatment liquid L may be stopped.

[0115] (2) Even when multiple concentration meters D are used instead of one, it is possible to check whether each concentration meter D is functioning normally. For example, a concentration meter D may be provided on each of the paths connecting t4 and t2 and t4 and t1 shown in Fig. 1 above. Also, the buffer tank T3 may be omitted, and the processing liquid L may be supplied from the recovery tank T2 to the supply tank T1.

[0116] (3) In the above embodiment, the processing liquid L is diluted by adding water, but it may be diluted, i.e., the concentration may be reduced, by adding new liquid of a low concentration. Furthermore, since it is sufficient that the concentration and temperature of the processing liquid L can be controlled to predetermined values ​​when it is supplied to the processing device 100, the target concentrations of the buffer tank T3 and the recovery tank T2 do not necessarily need 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, the target value may be changed depending on the difference between the controllability of heating and the controllability of water addition.

[0117] (4) The whole or a part of the inspection unit 23 and the memory unit 25 are not limited to being configured in the control device E that controls the entire treatment liquid supplying apparatus 1. They may be configured in a control device separate from the control device E, or may be configured in the control unit of the thermometer TM, the concentration meter D, etc.

[0118] [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]

[0119] 1 Processing liquid supply device 2. Recovery tank 4T New Liquid Tank 10a~40a container 12 Power source 20a: Container 21 Substrate processing control section 22 Concentration control section 23 Inspection Department 24 Cleaning Processing Section 25 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 231 Temperature setting section 232 Heating control section 233 Judgment section B. Barometer C Common flow path D Densitometer E. Control device Ei Input section Eо Output section F Filter H heating section H1~H4 heaters I Dilution section K Cleaning solution supply circuit 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 TM thermometer V1a~V6b, Vk1, Vk2, 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 tank for storing the treatment liquid; a supply path for supplying the processing solution from the tank to the processing device; A heating unit that heats the treatment liquid; a thermometer for measuring the temperature of the treatment liquid; a concentration meter for measuring the concentration of the processing liquid; an inspection unit that inspects the densitometer; having The inspection unit includes: a temperature setting unit that sets a boiling point temperature at which a predetermined concentration is achieved as a predetermined temperature based on the atmospheric pressure at a location where the processing liquid supply device is installed and a preset vapor pressure curve of the processing liquid; and a heating control unit that heats the processing liquid with the heating unit to a target temperature within a predetermined range based on the predetermined temperature; a determination unit that determines whether or not the concentration of the treatment liquid at the target temperature measured by the concentration meter is within a predetermined range based on the predetermined concentration; A processing liquid supplying device having the same.

2. when the determining unit determines that the concentration is not the target concentration but is higher than the target concentration, the heating control unit dilutes the treatment liquid to a concentration lower than the target concentration and a temperature lower than the target temperature, and then causes the heating unit to heat the treatment liquid again to the target temperature; 2. The processing liquid supplying device according to claim 1, wherein the determining unit determines again whether the concentration of the processing liquid measured by the concentration meter at the target temperature is equal to the target concentration.

3. 3. The processing liquid supplying apparatus according to claim 2, further comprising an output section that outputs information informing said determination section when said determination section determines again that said concentration is not the target concentration.

4. 4. The processing liquid supplying device according to claim 1, further comprising a cleaning processing section for cleaning the concentration meter when the determining section determines that the concentration is not the target concentration.

5. 5. The processing liquid supplying apparatus according to claim 1, further comprising a barometer for measuring the atmospheric pressure.

6. A dilution unit that dilutes the treatment liquid with a dilution liquid, The tank is 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 new liquid tank for supplying new processing liquid; Including, 6. A processing liquid supply device as described in any one of claims 1 to 5, further comprising a concentration control unit which adjusts the concentration of the processing liquid in the supply tank, the recovery tank and the new liquid tank by controlling the heating unit and the dilution unit based on the concentration measured by the concentration meter when the judgment unit determines that the concentration is the target concentration.

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

8. a boiling point temperature at which a predetermined concentration is achieved is set as a predetermined temperature based on the atmospheric pressure at a location where a processing liquid supplying device that supplies the processing liquid to a processing device that processes a substrate with the processing liquid is installed and a preset vapor pressure curve of the processing liquid; heating the treatment liquid by a heating unit so that a temperature of the treatment liquid measured by a thermometer becomes a target temperature within a predetermined range based on the predetermined temperature; A method for inspecting a processing liquid supply device, which inspects whether a concentration meter that measures the concentration of the processing liquid is functioning normally by determining whether the concentration of the processing liquid measured by the concentration meter when the processing liquid reaches the target temperature is a target concentration that is within a predetermined range based on the predetermined concentration.

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