KR0156453B1 - Method and a substrate treating apparatus utilizing the same - Google Patents

Abstract

A concentration control method and apparatus for measuring the transmitted light intensity of a treatment liquid and a solvent thereof and controlling the concentration of the treatment liquid based on the measurement result, wherein the temperature and transmitted light are measured by varying the solvent temperature and measuring the transmitted light intensity at each temperature. Calibration curve data indicating the relationship between the intensity and the calibration light intensity (reference transmission intensity) of the reference treatment solution adjusted to a predetermined concentration and temperature and the transmission light intensity (reference transmission intensity) of the solvent to measure the temperature and calibration curve of the reference treatment solution From the data, the predicted transmission intensity when the temperature of the solvent is the same as the reference treatment solution is obtained, and the correction coefficient is calculated from the ratio of the reference transmission intensity and the prediction transmission intensity, and the reference treatment is performed at the reference transmission intensity and the reference transmission intensity and the correction coefficient. Obtain the liquid transmittance (reference transmittance). Thereafter, the transmission light intensity (sample transmission light intensity) of the processing liquid actually used for the processing of the substrate is measured, and the sample transmission ratio of the processing liquid at the sample transmission light intensity and the reference transmission intensity and the correction coefficient is calculated according to the reference transmission rate and the sample transmission rate. To control the concentration.

Description

Concentration control method and substrate processing apparatus using the same

1 is a schematic view showing a schematic configuration of a substrate processing apparatus according to a first embodiment,

2 is a flowchart of the reference setting process according to the first embodiment,

3 is a graph showing an example of calibration curve data according to the first embodiment,

4 is a flowchart of a feedback control process according to the first embodiment,

5 is a schematic view showing a schematic configuration of a substrate processing apparatus according to a second embodiment,

6 is a flowchart of the reference setting process according to the second embodiment,

7 is a graph showing an example of calibration curve data according to the second embodiment;

8 is a flowchart of a feedback control process according to the second embodiment,

9 is a schematic view showing a schematic configuration of a modification of the substrate processing apparatus;

10 is a block diagram showing a modification of the photodetector,

11 is an exploded perspective view of an example of a flow cell for measuring transmission light,

12 is a horizontal sectional view of an example of a flow cell for measuring transmitted light,

13 is a longitudinal sectional view of an example of a flow cell for measuring transmitted light,

14 is a graph comparing the specific transmittance by various coatings,

15 is a schematic configuration diagram of an example of an optical system for measuring transmitted light,

16 is a timing chart showing the operation of the optical path switching control unit and the measurement timing of the transmitted light intensity measurement unit.

17 is a diagram showing a modification of the photodetector,

18 is a schematic configuration diagram showing a modification of the optical system for measuring transmitted light,

19 is a timing chart showing the operation of the optical path switching controller and the measurement timing of the transmitted light intensity measurement unit.

* Explanation of symbols for main parts of the drawings

1: Treatment tank 1a: Treatment tank body

1b: overflow portion 3: pure water supply piping

5: chemical liquid tank 7: chemical liquid supply piping

9: Treatment liquid supply piping 11: Pump

13 heater 15 temperature sensor

17 filter 19 sample flow cell

21: light source 22: optical branch

23: reference cell 24: optical path switching unit

25: photo detector 30: concentration control unit

31: transmitted light intensity measuring unit 32: temperature control unit

33: calibration curve data measuring section 34: calibration curve data storage section

35: correction coefficient calculation unit 36: transmittance calculation unit

37: feedback control unit 38: supply amount control unit

39: optical path switching controller 41a, 41b: frame

42: through hole 43: 0 ring

44a, 44b: light transmitting part 45: spacer

The present invention calculates the transmittance of the treatment liquid with the ratio between the transmitted light intensity of the treatment liquid used for the treatment of the substrate and the transmitted light intensity of the solvent contained in the treatment liquid, and calculates the transmittance of the treatment liquid based on the transmittance. A concentration control method for controlling the concentration of the processing liquid and the concentration of the processing liquid is used to clean the substrates such as semiconductor wafers, glass substrates for photomasks, glass substrates for liquid crystal display devices, and substrates for optical disks. The present invention relates to a substrate processing apparatus that performs processing such as etching or etching.

As a conventional substrate processing apparatus of this kind, there is a substrate processing apparatus for cleaning a substrate. In order to clean substrates such as semiconductor wafers, the apparatus of the substrate treatment is to mix the chemical liquid and the pure water (solvent) at a predetermined ratio according to the purpose thereof to adjust the cleaning liquid, and the substrate in the cleaning liquid at this predetermined concentration. The substrate is treated by dipping. However, since the cleaning liquid is often used in a state heated at, for example, about 70 ° C, the concentration varies depending on evaporation of pure water or chemical liquid and other factors. If the concentration of the cleaning liquid is fluctuated, the substrate cannot be in a state of required cleaning even if the cleaning is performed for a predetermined time. Therefore, it is necessary to control the concentration to control the predetermined concentration if there is a variation. As a method for controlling the concentration of a treatment liquid such as a cleaning liquid, the transmittance of the treatment liquid is calculated by a ratio between the transmission light intensity (sample transmission light intensity) of the treatment liquid and the transmission light intensity (reference transmission light intensity) of the pure water serving as a reference. There is a method of controlling the concentration of the treatment liquid on the basis of. According to this method, it is necessary to measure the transmittance of the processing liquid in order to control the concentration of the processing liquid.

As a method for measuring the transmittance, a permeation field flow flow cell is arranged in a processing liquid supply pipe for supplying a processing liquid, and the transmission light intensity of the processing liquid is measured, and the transmission light intensity of pure water is measured with a reference cell. Then, there is a method of obtaining the transmittance of the treatment liquid based on pure water based on these ratios.

However, as described above, in the cleaning of substrates such as semiconductor wafers, the treatment is performed while the cleaning liquid is heated. On the other hand, since the pure water contained in the cleaning liquid has a temperature dependence on its absorption coefficient, the transmitted light intensity of the cleaning liquid is measured higher than that at normal temperature. However, since the reference transmission light intensity of pure water is measured as it is at room temperature, it is not measured higher than room temperature like a cleaning liquid.

Therefore, an error is included in the transmittance of the cleaning liquid obtained at these ratios due to the temperature dependence of the extinction coefficient of pure water. Therefore, in this method, it is difficult to precisely control the concentration of the processing liquid used for processing the substrate based on the transmittance of the processing liquid obtained, and in particular, it is difficult to apply to the substrate processing apparatus for cleaning the semiconductor wafer.

As a technique to improve the above problems, the measurement of the transmitted light intensity is measured by continuously or intermittently introducing the treatment liquid from the treatment tank filled with the treatment liquid in a collecting tube different from the treatment supply pipe in which the flow cell is arranged. The technique is known (for example, see Japanese Patent Laid-Open No. 62-8040). According to this method, the transmitted light intensity of the treatment liquid can be measured at a temperature approximately equal to the temperature of the pure water used as the reference by cooling or leaving the collected treatment liquid. Therefore, the transmittance of the processing liquid can be obtained with high accuracy without any error due to temperature dependence. As a result, the concentration of the processing liquid can be controlled with high precision.

However, in the case of the conventional example having such a configuration, in order to measure the transmitted light intensity of the treatment liquid, it is necessary to collect the treatment liquid in a collecting tube and to cool or leave it to the same temperature as pure water as a reference. Therefore, this conventional example has the advantage that the concentration of the treatment liquid can be measured and controlled with high accuracy, while it takes time to collect the treatment liquid from the collection tube and cool or leave it, and thus the response to the concentration change of the treatment liquid There is a problem that sex is bad.

This invention is made in view of such a situation, Comprising: It aims at providing the density control method with high precision and responsiveness, and the substrate processing apparatus using the same which correct | amend the temperature dependence of a process liquid.

The present invention adopts the following configuration to achieve this object.

That is, in the first invention, the transmission light intensity of the processing liquid used for processing the substrate is measured by the first transmission light intensity measuring means, and the transmission light intensity of the solvent constituting the processing liquid is measured by the second transmission light intensity. A concentration control method for controlling the concentration of the treatment liquid based on the results of their measurement as measured by the means, the method comprising the following steps: (a) The solvent while varying the temperature of the solvent constituting the treatment liquid; Storing the calibration curve data indicating the relationship between the solvent temperature and the transmitted light intensity by measuring the transmitted light intensity of the bay by the first transmitted light intensity measuring means; (b) measuring, by the first transmitted light intensity measuring means, the transmitted light intensity of the reference treatment liquid prepared at a predetermined concentration and temperature as the reference transmitted light intensity; (c) measuring the transmitted light intensity of the solvent by the second transmitted light intensity measuring means as the reference transmitted light intensity; (d) Predicted transmitted light corresponding to the transmitted light intensity of the solvent to be measured by the second transmitted light intensity measuring means when the solvent is at the same temperature as the reference processing liquid based on the temperature of the reference processing liquid and stored calibration data. Calculating a correction factor at a ratio between the reference transmitted light intensity and the predicted transmitted light intensity by calculating the intensity; (e) calculating, as the reference transmittance, the transmittance of the reference treatment liquid at the predetermined temperature in the reference transmittance intensity and the reference transmittance intensity and the correction coefficient; (F) measuring the transmitted light intensity of the processing liquid actually used for the processing of the substrate by the first transmitted light intensity measuring means as the sample transmitted light intensity after performing the reference setting process to be performed; (g) calculating the transmittance of the treatment liquid as the sample transmittance at the sample transmittance intensity and the reference transmittance intensity and the correction coefficient; (h) controlling the concentration of the treatment liquid to be actually used for processing the substrate according to the reference transmittance and the sample transmittance; The feedback control process is repeated so that the reference transmittance and the sample transmittance coincide.

The operation of the first invention method described above is as follows.

The method of the present invention calculates the transmittance with a ratio between the transmitted light intensity of the treatment liquid and the transmitted light intensity constituting the treatment liquid. And it is a density control method of controlling a density | concentration based on the calculated transmittance | permeability.

This transmittance, as is well known, can be expressed in Lambert-Beer's law: Where I _o is the incident light intensity, I is the transmitted light intensity, and α is an integer indicating the extent to which the medium absorbs light according to Lambert's law, and the extinction coefficient has a unique value depending on the medium. Here, the extinction coefficient α represents the extinction coefficient of the treatment liquid, and αv represents the extinction coefficient of the solvent. In addition, the concentration c indicates the concentration of the treatment liquid and the concentration cv indicates the concentration of the solvent.

D is an optical path arranged in the flow path of the flow cell for transmission light measurement, and is the length (optical path length) of light passing through the liquid.

By the way, the transmittance | permeability is calculated | required from ratio with the incident light intensity measured substantially simultaneously with the transmitted light intensity measured as shown by said Formula (1). However, in order to do so, it is necessary to measure the light intensity (incident light intensity) of the light source, which complicates the optical system for measuring transmitted light. Therefore, it is common to measure the transmission light intensity (reference transmission light intensity) of the solvent as a reference without measuring the incident light intensity, and to make the transmittance with the ratio of the transmission light intensity (sample transmission light intensity) of the treatment liquid to this.

Thus, using another transmission light measuring flow cell (hereinafter referred to as a reference cell) having the same optical path length (d) as the flow cell for measuring the transmitted light (hereinafter referred to as a sample flow cell) of the treatment liquid, a solvent is added thereto. Fill and maintain at a constant temperature. The transmittance is calculated based on the transmitted light intensity of this reference cell. In general, the treatment liquid is often used in a state of being heated to a predetermined temperature, and thus the transmitted light intensity is largely displaced due to the temperature dependence of the extinction coefficient. For this reason, the sample transmitted light intensity of the treatment liquid is displaced, but since the solvent of the reference cell is maintained at a constant temperature without heating, the reference transmit light intensity remains almost constant. Therefore, the transmittance calculated from this ratio includes an error due to the temperature dependence of the extinction coefficient.

In the method of the present invention, the temperature dependence of the extinction coefficient is corrected according to the following procedure to determine the transmittance without error, and concentration control is performed based on this.

First, the transmission light intensity of only the solvent is measured by the first transmission light intensity measuring means while changing the temperature of the solvent constituting the treatment liquid. The calibration curve data indicating the relationship between the transmitted light intensity I of the solvent and the temperature T is stored (process of (a)). This calibration curve data is generally a graph that goes up to the right, where the transmitted light intensity increases, such as the degree control.

Next, a processing liquid is prepared so as to have a predetermined concentration (c) and a predetermined temperature (t _e ) in advance, and this is referred to as "reference processing liquid". The transmitted light intensity (reference transmitted light intensity I _R ) of this reference treatment liquid is measured by the first transmitted light intensity measuring means (process of (b)). This reference transmitted light intensity (I _R ) is expressed as follows.

The transmitted light intensity (reference transmitted light intensity I _v ) of the solvent serving as a reference for the transmittance is measured by the second transmitted light intensity measuring means (process of (c)). This solvent is maintained at a constant temperature (t _v ). The reference transmitted light intensity I _v is expressed as follows.

Next, the transmitted light intensity (predicted transmitted light intensity I _F ) to be measured by the second transmitted light intensity measuring means when the solvent maintained at a constant temperature (t _v ) is set to the same temperature (t _e ) as the reference treatment liquid. To calculate. To calculate this, the calibration curve data memorized in the above step (a) is used.

The predicted transmitted light intensity I _F is expressed by the following equation.

The ratio between the reference transmitted light intensity I _v and the predicted transmitted light intensity I _F obtained from the calibration curve data is a correction coefficient K (process of (d)).

Then, the transmittance (reference transmittance) T _R of the reference treatment liquid at the predetermined temperature at the reference transmittance intensity (I _v ) and the correction coefficient (K) of the reference transmittance intensity (I _R ) is obtained as follows. (the process of (e)).

If you substitute this formula (6) into (2), (4)

It can be seen that the reference transmittance (T _R ) does not have a temperature dependency of the extinction coefficient of the solvent. The reference transmittance (T _R ) is set in advance by the standard setting procedure as described above.

Next, the transmission light intensity of the "treatment solution" to the temperature and concentration, such as based on the processing solution to the target (sample transmission light intensity I _s) the (process of (f)) The measured by a transmission light intensity measuring means of Fig. The sample transmission light intensity (I _s) is expressed by the following equation.

Then, the transmittance (sample transmittance T _s ) of the "treatment liquid" is obtained from the sample transmit light intensity (I _s ) and the reference transmit light intensity (I _v ) and the correction coefficient (K) measured in the reference setting process ((g) Process).

As for the sample transmittance T _s , the temperature of the solvent of the sample transmitted light intensity I _s and the predicted transmitted light intensity I _F is the same at te, and thus there is no influence of the temperature dependence of the absorption coefficient of the solvent.

Next, the concentration of the processing liquid to be actually used for processing the substrate is controlled according to the reference transmittance T _R and the sample transmittance T _s set in the reference setting process (step (h)). T _R , T _s ) are values related to the concentration (c), respectively. For example, depending on the difference between the permeability (T _R , T _s ), one of the chemical liquid, the gas corresponding to the chemical liquid, and the solvent The process liquid is replenished, and the concentration (c) is prepared by repeating the pieceback control process of the above-described processes (f) to (h).

In addition, when the concentration (c) is obtained from the formulas (7) and (9), respectively, for the sample transmittance (T _s ) and the reference transmittance (T _R ),

Becomes Here, if the concentration c of the treatment liquid is c ', the concentration difference Δc is

Becomes Therefore, it can be seen that when the sample transmittance T _s and the reference transmittance T _R are controlled to be the same value, the concentration c of the treatment liquid and the concentration c of the reference treatment liquid can be matched. The sample transmittance (T _s ) and reference transmittance (T _R ) can be controlled with high accuracy because the influence of the temperature dependence of the solvent is removed by the correction coefficient (K). In addition, since the treatment liquid does not need to be cooled in order to match the temperature of the solvent when the reference transmitted light intensity is measured, the concentration can be controlled with good responsiveness.

In addition, since the concentration control is performed based on the transmittance related to the concentration without obtaining the concentration, it is not necessary to perform the calculation for the concentration calculation, and the burden of the calculation processing can be reduced.

In the second invention, the transmission light intensity of the processing liquid used for processing the substrate and the transmission light intensity of the solvent constituting the processing liquid are measured by common transmission light intensity measuring means, and the concentration of the processing liquid is determined based on the measurement result. As a concentration control method for controlling, the method includes the following steps: (a) The transmitted light intensity of the solvent alone is measured by the transmitted light intensity measuring means while varying the temperature of the solvent constituting the treatment liquid, Storing calibration curve data indicating a relationship between temperature and transmitted light intensity; (b) measuring the transmitted light intensity of the reference treatment liquid previously adjusted to a predetermined concentration and temperature by the transmitted light intensity measuring means as the reference transmitted light intensity; (c) measuring the transmitted light intensity of the solvent as said transmitted light intensity by said transmitted light intensity measuring means; (d) The estimated transmitted light intensity corresponding to the transmitted light intensity of the solvent to be measured by the transmitted light intensity measuring means when the solvent is at the same temperature based on the temperature of the reference processing liquid and the stored calibration data. Calculating a correction factor based on a ratio between the reference transmitted light intensity and the predicted transmitted light intensity; (e) calculating the transmittance of the reference treatment liquid at the predetermined temperature as the reference transmittance based on the reference transmittance intensity and the reference transmittance intensity and the correction coefficient; (F) measuring the transmitted light intensity of the processing liquid actually used for processing the substrate as the sample transmitted light intensity by means of the transmitted light intensity measuring means; (g) calculating the transmittance of the treatment liquid as the sample transmittance at the sample transmittance intensity and the reference transmittance intensity and the correction coefficient; (h) controlling the concentration of treatment liquid that the substrate should actually use for treatment in accordance with the reference transmittance and the sample transmittance; The feedback control process is repeated so that the reference transmittance and the sample transmittance coincide.

Since the second invention is the same as the first invention except that the angle of transmitted light is measured by a common transmission light intensity measuring means, the description of its operation is omitted.

In the first and second inventions, preferably, before or after the process of (f) in each invention method, the process of (c) is repeated to measure the reference transmission light intensity, and this and the predicted transmission light After obtaining the correction coefficient from the ratio with the intensity, the procedure of (g) is performed.

In this way, even if there is a temporal fluctuation in the luminous intensity of the light source included in the transmitted light intensity measuring means, the correction coefficient can be accurately obtained, and as a result, the sample transmittance can be accurately calculated.

In detail, as described above, the sample transmittance T _s is obtained from the sample transmit light intensity I _s and the reference transmit light intensity I _v and the correction coefficient K measured during the reference setting process. This is that the reference transmitted light intensity (I _v) is equal to the reference value of the transmission light intensity at this time at the time of measuring the sample transmitted light intensity (I _s) of the treatment solution (I _v) and a reference set-up process is the premise. However, there is a possibility that the reference transmitted light intensity I _v is fluctuated by temporal light intensity fluctuation of the light source. At this inconsistent reference transmittance (I _v ) (correction coefficient K), the sample transmittance (T _s ) cannot be accurately calculated using Eq. (9). Therefore, the reference transmittance intensity I _v is measured again until this sample transmittance T _s is calculated. That is, the accurate correction coefficient (K) can be obtained by making the interval between the measurement of the sample transmission light intensity (I _s ) and the reference transmission light intensity (Iv) in the feedback control process sufficiently shorter than the interval of the light intensity variation. (T _s ) can be calculated.

Further, in the first and second inventions, preferably, the process of (a) in each invention method measures the transmitted light intensity at the respective temperatures and at the same time the light intensity of the light source at each temperature. The light source related light intensity is measured, and the ratio (transmission light intensity ratio) between the transmitted light intensity and the light source related light intensity at each temperature is stored as calibration curve data, and the above (b), (c) and (f) In each process of), the light source related light intensity is measured and the ratio between the angular transmittance intensity and the light source related light intensity is obtained by measuring the light intensity related to each light source in each process. Is done.

As the light intensity associated with the light source, for example, the light intensity of the light source is directly detected or the light intensity of the light source is indirectly detected through photosensitive means such as a filter. Therefore, the transmitted light intensity ratio is almost constant even if the light intensity of the light source is varied and is invariant. The transmitted light intensity ratio which is not affected by the fluctuation of the light source light intensity is stored as calibration curve data. In the following description, the incident light intensity I _o used by the above-described formula (1) as the light source related light intensity is used as an example. In other words, as the calibration curve data, the relationship between the transmitted light intensity ratio (transmitted light intensity I / incident light intensity I _o ) and the temperature T is stored.

In each of the steps (b), (c), and (f), the light source related light intensity (incident light intensity I _o ) is measured, and the angle transmitted light intensity and the light source related light intensity are measured as in the measurement of the angle transmitted light intensity. Calculate the ratio of and calculate the operation based on these ratios in each process.

That is, in the process of (b), the transmission light intensity (reference transmission light intensity I _R ) of the reference treatment liquid prepared at a predetermined concentration and temperature is measured at the same time, and the incident light intensity (I _o ) is measured and the ratio thereof is measured. (Reference transmitted light intensity I _R / incident light intensity I _o ) is obtained as the reference transmitted light intensity ratio (R _R ). In the process of (c), the transmission light intensity (reference transmitted light intensity I _v ) of the solvent is measured and the incident light intensity (I _o ) is measured, and the ratio (reference transmission light intensity I _v / incident light intensity I) is measured. _o ) is obtained as the reference transmission intensity ratio (R _v ). In the process (f), the transmission light intensity (sample transmission light intensity I _s ) of the processing liquid actually used for the processing of the substrate is measured and the incident light intensity (I _o ) is measured, and their ratio (sample transmission light) is measured. The intensity I _s / incident light intensity I _o ) is obtained as the sample transmission light intensity ratio (R _s ).

And in each process, an operation is performed as follows.

In the process of (d), the predicted transmittance intensity ratio (R _E ) corresponding to the reference transmittance intensity when the solvent is the same as the reference treatment solution in the temperature of the reference treatment solution and the calibration curve data (predicted transmission intensity I _F / incident light intensity) I _o ) In addition, the reference transmitted light intensity ratio (R _v) (see the transmitted light intensity I _v / incident light intensity I _o) and the predicted transmitted light intensity ratio (R _F) correction on the ratio of the (predicted transmission light intensity I _F / incident light intensity I _o) factor ( K)

In this case, the correction coefficient K is the ratio between the reference transmission intensity I _v and the predicted transmission intensity I _F , which is (I _v / I _o ) / (I _F / I _o ), which is the correction coefficient K = I _v / I _F This is a form similar to the above-mentioned formula (5).

Here, the angle transmitted light intensity (I _v , I _F ) is the value is shifted by the light intensity of the light source. That is, they become natural when the luminous intensity of a light source falls and falls accordingly. However, since the transmitted light intensities I _v and I _F are not used as they are, they are set as a ratio with the light source related light intensity (here, incident light intensity I _o ) related to the light intensity of the light source, so that the light intensity of the light source is not affected. . Therefore, at the time when the calibration curve data is measured and the light intensity are measured, even if there is a variation in the light intensity of the light source, each value can be calculated accurately.

Further, in step (e), the reference transmittance intensity ratio (R _R ) (= I _R / I _o ), the reference transmittance intensity ratio (R _v ) (= Iv / Io), and the correction coefficient (K) (= I _v / I _{In F} ), the transmittance (reference transmittance T _R ) of the reference treatment solution is obtained. Here, the reference transmittance (T _R ) is expressed as T _R = K · R _R / R _v ,

It can be seen that the formula (6) described above, that is, the formula (7) described above, and the reference transmittance (T _R ) do not have a dependency of the temperature of the extinction coefficient of the solvent.

In the process (f), the sample transmission light intensity (I _s ) / incident light intensity (I _o ) is obtained as the sample transmission light intensity ratio (R _s ), and in the process (g), the sample transmission light intensity ratio (R _s ) (= I _s / I _o ), the sample transmittance (T _s ) of the treatment liquid is obtained from the reference transmission intensity ratio (R _v ) (= I _v / I _o ) and the correction coefficient (K) (= I _v / I _F ). Here, the sample transmittance (T _s ) is expressed as T _s = K · R _s / R _v ,

It turns out, and it turns out that it becomes a form similar to Formula (9) mentioned above.

In addition, since the reference transmittance (T _R ) and the sample transmittance (T _s ) are calculated based on the ratio of the incident light intensity (I _o ), which is the light intensity related to the light source, respectively, the angular transmittance can be calculated accurately even if the light source intensity is shifted. have. Therefore, the density control can be performed accurately over a long period without being affected by the light intensity fluctuation of the light source.

The third invention is a substrate processing apparatus using the first invention method.

That is, the third invention is a substrate processing apparatus for processing a substrate by a processing liquid prepared at a predetermined concentration and temperature, the apparatus comprising the following elements: substrate storage means for storing a substrate to be processed; Processing liquid storage means for storing the processing liquid for processing the substrate accommodated in the substrate storage means; Chemical liquid supply means for supplying a chemical liquid constituting the processing liquid or a gas thereof to the processing liquid storage means; Solvent supply means for supplying a solvent constituting the treatment liquid to the treatment liquid storage means; Processing liquid supply means for supplying the processing liquid stored in the processing liquid storage means to the substrate accommodated in the substrate storage means; First and second sampling means having light transmitting portions having the same optical path length; The transmission light intensity (reference transmission light intensity) of the reference processing liquid adjusted to a predetermined concentration and temperature in advance is measured using the first sampling means, and the transmission light intensity of the processing liquid actually used for processing the substrate (sample transmission light). First transmitted light intensity measuring means for measuring the intensity) using the first sampling means; Second transmission light intensity measuring means for measuring the transmission light intensity (reference transmission light intensity) of the solvent constituting the processing liquid by using a second sampling means; Calibration curve data collection to measure the transmitted light intensity of only the solvent using the first sampling means while changing the temperature of the solvent constituting the treatment solution, and to collect calibration curve data indicating the relationship between the temperature of the solvent and the transmitted light intensity. Way; Based on the temperature of the reference treatment solution and the collected calibration curve data, the transmission light intensity measured by the second transmission light intensity measurement means using the second sampling means when the solvent is at the same temperature as the reference treatment solution. Correction coefficient calculating means for calculating a corresponding estimated transmission light intensity and calculating a correction coefficient at a ratio between the reference transmission light intensity and the prediction transmission light intensity; Reference transmittance calculation means for calculating, as a reference transmittance, the transmittance of the reference treatment liquid at the predetermined temperature in reference transmittance intensity and reference transmittance intensity and correction coefficient; Sample transmittance calculation means for calculating a transmittance of the processing liquid as a sample transmittance using a sample transmittance intensity and a reference transmittance intensity and a correction coefficient; Concentration control means for controlling the concentration of the processing liquid to be actually used for processing the substrate by controlling the chemical liquid supply means and the solvent supply means in accordance with the reference transmittance and the sample transmittance.

The operation of the substrate processing apparatus according to the third invention is as follows.

First, the calibration curve data collection means measures the transmitted light intensity at each temperature while changing the temperature of the solvent constituting the treatment liquid, and collects the calibration curve data indicating the relationship between the solvent temperature and the transmitted light intensity. do.

Then, the first transmitted light intensity measuring means measures the transmitted light intensity (standard transmitted light intensity) of the reference treatment liquid prepared at a predetermined concentration and temperature in advance by using the first sample collecting means. Also, the second transmitted light intensity measuring means measures the transmitted light intensity (reference transmitted light intensity) of the solvent constituting the processing liquid by using the second sample collecting means.

Thereafter, the correction coefficient calculating means calculates the transmitted light intensity (predicted transmitted light intensity) when the temperature of the solvent is the same as that of the reference treatment solution based on the temperature of the reference treatment solution and the collected calibration curve data. The correction coefficient is calculated from the ratio of the estimated transmitted light intensity. Further, the reference transmittance calculating means calculates the transmittance (reference transmittance) of the reference treatment liquid at the predetermined temperature from the reference transmittance intensity and the reference transmittance intensity and correction coefficient. As such, since the temperature dependency of the reference transmittance is corrected by the correction coefficient, the reference transmittance can be accurately calculated.

Next, the first transmitted light intensity measuring means measures the transmitted light intensity (sample transmitted light intensity) of the processing liquid actually used for processing the substrate using the first sample collecting means. Then, the sample transmittance calculating means calculates the transmittance (sample transmittance) of the processing liquid from the sample transmittance intensity and the reference transmittance intensity and the correction coefficient. Thus, since the temperature dependence of the sample transmittance is corrected by the correction coefficient, the sample transmittance can be accurately calculated.

The concentration control means adjusts the concentration of the treatment liquid stored in the treatment liquid storage means by controlling the chemical liquid supply means and the solvent supply means in accordance with the reference transmittance and the sample transmittance. The concentration-adjusted treatment liquid is supplied to the substrate stored in the substrate storage means by the treatment liquid supply means.

4th invention is a substrate processing apparatus using the 2nd invention method.

That is, the fourth invention is a substrate processing apparatus for processing a substrate by a processing liquid adjusted to a predetermined concentration and temperature, the apparatus including the following elements; Substrate storage means for storing a substrate to be processed; Processing liquid storage means for storing the processing liquid for processing the substrate accommodated in the substrate storage means; Chemical liquid supply means for supplying a chemical liquid constituting the processing liquid or a gas thereof to the processing liquid storage means; Solvent supply means for supplying a solvent constituting the treatment liquid to the treatment liquid storage means; Processing liquid supply means for supplying the processing liquid stored in the processing liquid storage means to the substrate accommodated in the substrate storage means; Sampling means for separately collecting the processing liquid and the solvent constituting the light having a light transmission portion having a predetermined optical path length; The intensity of light transmitted through the sampling means obtained by collecting the reference treatment liquid adjusted to a predetermined concentration and temperature in advance (reference transmitted light intensity) is measured, and the reference transmitted light intensity and the intensity of light generated by the light irradiation means (light source related light). The intensity of the light transmitted through the sampling means obtained by collecting only the solvent constituting the treatment liquid, and the reference transmitted light intensity and the light generated by the light irradiation means. The ratio between the intensity is determined as the reference transmittance intensity ratio, and the intensity of the light transmitted through the sampling means obtained by collecting the processing liquid actually used for processing the substrate (sample transmission intensity) is measured. Transmission light intensity ratio measuring means for obtaining a ratio of the intensity of light generated by the means as a sample transmission light intensity ratio; Calibration curve data collection means for measuring the transmission light intensity of only the solvent using a sampling means while changing the temperature of the solvent constituting the treatment liquid, and collecting calibration curve data indicating a relationship between the temperature of the solvent and the transmission light intensity; Based on the temperature of the reference treatment solution and the collected calibration curve data, the predicted transmission intensity corresponding to the transmitted light intensity measured by the sampling means when the solvent is at the same temperature as the reference treatment solution and the light generated by the light irradiation means Correction coefficient calculating means for obtaining a ratio between the intensity and the ratio as the predicted transmittance intensity ratio and calculating a correction coefficient from the ratio between the reference transmittance intensity ratio and the predicted transmittance intensity ratio; Reference transmittance calculating means for calculating, as a reference transmittance, a transmittance of the reference treatment liquid at the predetermined temperature in a reference transmittance intensity ratio and a reference transmittance intensity ratio and a correction coefficient; Sample transmittance calculation means for calculating a transmittance of the processing liquid as a sample transmittance at a sample transmittance intensity ratio, a reference transmittance intensity ratio, and a correction coefficient; Concentration control means for controlling the concentration of the processing liquid to be actually used in the processing of the substrate by controlling the chemical liquid air permeation means and the solvent supply means in accordance with the reference transmittance and the sample transmittance.

The operation of the substrate processing apparatus according to the fourth invention is as follows.

The apparatus of the present invention is different from the substrate processing apparatus of the third invention in terms of using a common sampling means for collecting the processing liquid and the solvent and for measuring the light intensity associated with the light source.

The calibration curve data collection means measures the transmitted light intensity at each temperature while changing the temperature of the solvent constituting the processing liquid by using the sampling means, and collects the calibration curve data indicating the relationship between the solvent temperature and the transmitted light intensity.

Then, the transmission light intensity ratio measuring means measures the transmission light intensity (reference transmission light intensity) of the reference treatment liquid previously adjusted to a predetermined concentration and temperature by using a sample collecting means and at the same time the intensity of light generated from the light irradiation means (light source related) Light intensity) is measured and the ratio (reference transmitted light intensity) between the reference transmitted light intensity and the light intensity related to the light source is obtained. In addition, the transmission light intensity ratio measuring means measures the intensity (reference transmission light intensity) of the light transmitted through the sampling means in which only the solvent constituting the processing liquid is collected (the reference transmission intensity ratio). )

Subsequently, the correction coefficient calculating means calculates the transmitted light intensity (predicted transmitted light intensity) when the temperature of the solvent is the same as the reference treatment liquid based on the temperature of the reference treatment liquid and the collected inspection data. A ratio (predicted transmission intensity ratio) with respect to the light source related light intensity is obtained to calculate a correction coefficient from the reference transmission intensity ratio and the predicted transmission intensity ratio. In this case, the light intensity related to the light source is related to both the reference transmittance intensity ratio and the predicted transmittance intensity ratio, and therefore, when there is light intensity variation in the light source, both the reference transmittance intensity ratio and the predicted transmittance intensity ratio are displaced according to the light intensity variation of the light source. . Therefore, the light intensity variation of the light source does not affect the ratio between the reference transmission intensity ratio and the predicted transmission intensity ratio (reference transmission intensity ratio / prediction transmission intensity ratio), and as a result, a correction coefficient can be accurately obtained.

The reference transmittance calculating means calculates the transmittance (reference transmittance) of the reference treatment liquid at the predetermined temperature at the reference transmittance intensity ratio, the reference transmittance intensity ratio, and the correction coefficient. As such, since the temperature dependency of the reference transmittance is corrected by the correction coefficient, the reference transmittance can be accurately calculated.

Next, the transmission light intensity ratio measuring means measures the intensity (sample transmission light intensity) of the light transmitted through the sampling means obtained by collecting the processing liquid actually used for processing the substrate, and compares the sample transmission light intensity with the light source related light intensity. Obtain the ratio (sample transmission light intensity ratio).

Then, the sample transmittance calculating means calculates the transmittance (sample transmittance) of the processing liquid from the sample transmittance intensity ratio, the reference transmittance intensity ratio, and the correction coefficient. Thus, since the temperature dependence of the sample transmittance is corrected by the correction coefficient, the sample transmittance can be accurately calculated. In addition, since the ratio is obtained by the ratio between the angular transmittance intensity and the light intensity associated with the light source, the value of each ratio is invariant even when the light source fluctuates. The sample transmittance can be accurately calculated by removing the influence of the light intensity fluctuation of the light source.

Then, the concentration control means controls the chemical liquid supply means and the solvent supply means in accordance with the reference transmittance and the sample transmittance, thereby adjusting the concentration of the treatment liquid stored in the treatment liquid storage means. The concentration-treated processing liquid is supplied to the substrate stored in the substrate storage means by the processing liquid supply means.

In the substrate processing apparatus according to the third and fourth inventions described above, the concentration control means preferably includes a feedback control means for controlling the chemical liquid supply means and the solvent supply means in accordance with the difference between the reference transmittance and the sample transmittance. .

Further, in the substrate processing apparatuses according to the third and fourth inventions described above, the sample collecting means opposes a pair of light transmitting portions formed of a light transmissive material at predetermined intervals (cell length), and the light transmitting portion A transmission light measuring flow cell for measuring light intensity output from the other side of the light transmitting part by irradiating light from one side of the light transmitting part with respect to the fluid to be measured flowing between the liquid to be measured. It is preferable to form a film having corrosion resistance with respect to the fluid to be measured on the surface where it touches. By coating the light transmitting portion with a corrosion resistant film in this manner, the corrosion of the light transmitting portion by the treatment liquid can be prevented, and the material forming the light transmitting portion can also be prevented from eluting into the treatment liquid.

As such a film, the fluorinated resin which has corrosion resistance with respect to various chemicals and is excellent in heat resistance is preferable.

In the substrate processing apparatus according to the third aspect of the invention, preferably, the first and the second transmitted light intensity measuring means comprise a single light source which is used for both means, and the first and second light sources. And a single photodetector for branching toward the sampling means, a single photodetector for receiving light separately transmitted through the first and second sampling means and outputting a signal according to each intensity. And an optical path switching means for alternately injecting light transmitted separately from the second sampling means into the photodetector, and taking in a signal from the photodetector in synchronization with the switching timing of the optical path switching means, thereby causing the The output signal of the photodetector when receiving the light passing through the sampling means is referred to as the reference transmission intensity, and the output signal of the photodetector when the light detector receives the light passing through the first sampling means. Each measurement is made with reference transmittance intensity.

Similarly, in the substrate processing apparatus according to the fourth aspect of the invention, preferably, the transmission light intensity ratio measuring means comprises: collecting a sample of a single light source, an optical filter having a predetermined light sensitivity, and light generated from the light source; A light detector for branching toward the means and the optical filter, a single photodetector for receiving light transmitted separately from the sample collecting means and the optical filter and outputting a signal according to each intensity, and the sample collecting means and the optical And an optical path switching means for alternately injecting the light transmitted separately from the filter into the photodetector, and taking in a signal from the photodetector in synchronization with the switching timing of the optical path switching means so that the photodetector receives the light transmitted through the sampling means. The output signal of the photodetector at the time of receiving the light was measured as either the standard transmission light intensity, the reference transmission light intensity, or the sample transmission light intensity. Respectively measuring the output signal of the photo detector when receiving light transmitted through the optical filter as the intensity (light source associated light intensity) of the light generated in the light irradiation means.

With the above configuration, in the third invention device, the light of a single light source transmitted separately from the first and second sample collection means (the sample device and the optical filter in the fourth invention device) is respectively supplied to the optical path switching means. Since the incident light is alternately incident on a single photodetector, the influence of the light intensity over time and the variation of the transmitted light intensity due to the sensitivity of the photodetector is influenced by the reference transmitted intensity, the sample transmitted intensity, and the reference transmitted intensity (fourth invention). The device also extends to the light intensity associated with the light source. As a result, by determining the ratio of the light intensities, the influence of the fluctuation of the light source intensity over time is canceled out, and the concentration of the treatment liquid can be controlled with high precision.

Preferably, the optical path switching means includes a light selection shutter in which the light transmitting portion and the light shielding portion are formed in a plate shape at a predetermined ratio, and in the third invention, the transmitted light of the second sample collecting means and the transmitted light of the first sample collecting means ( In the fourth aspect of the present invention, it comprises a drive means for driving the light selection shutter to alternately irradiate the light detector with the transmitted light of the optical filter and the transmitted light of the sample collecting means. As a result, in the third invention apparatus, the transmitted light of the second sample collecting means and the transmitted light of the first sample collecting means are shortened in comparison with the time when the variation in the light source intensity and the sensitivity change of the photodetector occur. In the apparatus, the transmitted light of the optical filter and the transmitted light of the sampling means can be irradiated to the photodetector alternately, and the influence by the variation in the light source luminous intensity or the sensitivity of the photodetector is further reduced.

In the substrate processing apparatus according to the third aspect of the invention, preferably, the first and second transmission light intensity measuring means measure the transmission light intensity of each of the reference transmission light intensity and the sample transmission light intensity and measure the reference transmission light intensity. Repeatedly, the i-th (i is any natural number) ratio of transmitted light intensity to reference transmitted light intensity, the ratio of i + 1th transmitted light intensity to i-th reference transmitted light intensity, respectively i + The moving averages of the ratios of the transmitted light intensity and the reference transmitted light intensity which are adjacent to each other in time, such as the ratio between the first transmitted light intensity and the reference transmitted light intensity, are calculated.

Similarly, in the substrate processing apparatus according to the fourth aspect of the invention, preferably, the transmission light intensity ratio measuring means measures the transmission light intensity of each of the reference transmission light intensity, the reference transmission light intensity, and the sample transmission light intensity, and the measurement of the light source related light intensity. Repeatedly, the i-th (i is an arbitrary natural number) ratio of the transmitted light intensity to the light source related light intensity, the i + 1th transmitted light intensity to the i-th light source related light intensity, respectively, The moving average of the ratios of the transmitted light intensity and the light source related light intensity, which are adjacent to each other in time, such as the ratio of the i + 1th light source related light intensity, is calculated, and the reference transmission light intensity ratio, reference transmission light intensity ratio, and sample transmission light intensity ratio do.

In the third invention, the sample transmitted light intensity (or reference transmitted light intensity) and the reference transmitted light intensity are preferably measured simultaneously. Similarly, in the fourth invention, the sample transmitted light intensity (or reference transmitted light intensity or reference transmitted light intensity) and the light source related light intensity are ideally measured simultaneously. In practice, however, in the case of the third invention device, for example, when a single photodetector detects the reference transmission intensity and the sample transmission intensity, a considerable time is required for switching the light path. In the case of the fourth invention apparatus, since a single sampling means is used, a considerable time is required for switching the treatment liquid and the solvent. As a result, in the case of the third invention apparatus, the reference transmittance intensity and the sample transmittance intensity are Measure before and after time. The output signal of the photodetector then fluctuates over time, so that the measured sample transmitted light intensity increases with time even though the concentration of the fluid is constant. The reference transmission intensity also increases with time. For example, samples the transmission light intensity and the reference transmitted light intensity to that of the intensity (and therefore, the ideal amount of the simultaneous measurement of transmitted light intensity thereof ratio is 1: 1) of the sample transmitted light intensity to be measured I _sn (n is nth measurement of The reference transmission light intensity is I _Rn , and the sample transmission light intensity is first measured, and these are represented in a time-series relationship as I _S I _R1 I _S2 I _R2 I _S3 I _R3 I _S4 I _R4 . It becomes

Thus, the ratio between the first sample transmission light intensity (I _s1 ) and the reference transmission light intensity (I _R1 ) (transmittance T ₁₁ = I _s1 / I _R1 ), the second sample transmission light intensity (I _s2 ) and the first The relationship between the ratio (transmittance T ₂₁ = I _s2 / _R1 ) and the subsequent transmittance with reference transmission light intensity (I _R1 ) of T ₁₁ T ₂₁ T ₂₂ T ₃₂ T ₃₃ . It becomes

Compare this to the ideal simultaneous measurement: T ₁₁ 1, 1 T ₂₁ , 1 T ₂₂ , 1 T ₃₂ , 1 T ₃₃ . … It becomes Thus, the transmittance becomes a relationship of repeating "small" and "large" compared to the ideal measurement. By calculating the moving average of the ratio between the sample transmission light intensity and the reference transmission light intensity which are adjacent to each other in this relationship in time, it can be close to the ideal value when the sample transmission light intensity and the reference transmission light intensity are simultaneously measured. As a result, it is possible to suppress the influence of the sensitivity change of the photodetector and to accurately obtain the ratio between the sample transmitted light intensity and the reference transmitted light intensity. The same can be said for the fourth invention device.

For example, the transmittance | permeability is calculated | required by the method different from the above. In other words, the first of the sample transmitted light intensity (I _s1) and the reference transmitted light intensity (I _R1) with the ratio (transmittance _{T 11 = I s1 / I R1} ) and the second of the sample transmitted light intensity (I _s2) with the reference transmitted light If the magnitude relationship between the ratio (transmittance T ₂₂ = I _s2 / I _R2 ) and the transmittance thereafter with the intensity I _R2 is obtained, it is T ₁₁ T ₂₂ T ₃₃ .

Comparing this with the ideal simultaneous measurement, it becomes T ₁₁ 1, T ₂₂ 1, T ₃₃ 1. As described above, the transmittance is in a relationship of repeating "small" and "small" as compared with the ideal measurement, and it can be seen that even when a moving average is calculated for these, it cannot be close to the ideal value.

While several forms are presently considered to be illustrative of the invention, it should be understood that the invention is not limited to the illustrated configuration and method.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

A. First Embodiment Apparatus (Example of substrate processing apparatus using the first invention method)

1 is a schematic view showing a schematic configuration of a substrate processing apparatus according to a first embodiment using the method of the present invention.

In the drawing, reference numeral 1 denotes an overflow treatment tank. The treatment tank 1 is a treatment tank main body 1a in which a wafer carrier (not shown) in which a plurality of semiconductor wafers are stored is immersed, and arranged to surround the treatment tank body 1 so as to retain the processing liquid overflowed from the processing tank body 1a. It consists of the overflow part 1b. Pure water is supplied to the overflow portion 1b by a pure water supply pipe 3 at a predetermined pressure, and the supply amount thereof is regulated by the flow regulating valve V ₁ . In addition, the chemical liquid is supplied to the overflow portion 1b through the flow rate control valve V ₂ and the chemical liquid supply pipe 7 for controlling the flow rate of the chemical liquid in the chemical liquid tank 5. Therefore, the chemical liquid and the pure water are mixed in the overflow portion 1b to form a treatment liquid. Further, the pure water supply pipe 3 corresponds to the solvent supply means in the present invention, and the chemical liquid tank 5 and the chemical liquid supply pipe 7 correspond to the chemical liquid supply means.

In addition, one end side of the processing liquid supply pipe 9 is arranged in the overflow portion 1b to circulate the processing liquid, which is circulated with a pump 11 for circulating the processing liquid. A heater 13 for heating the present processing liquid to a predetermined temperature, a temperature sensor 15 for measuring the temperature of the processing liquid, a filter 17 for removing particles, etc. in the circulating processing liquid, Sample flow cells 19 having a predetermined optical path length d are arranged, and the other end side thereof is connected to the bottom of the processing tank body 1a.

Light from a light source 21 such as a halogen lamp is diverged in two directions by the light splitting section 22, and one of the sample flow cells 19 is irradiated. The other side is irradiated to the reference cell 23 having the optical path length d filled with pure water. Further, the pure water filled in the reference cell 23 may be configured to flow when necessary as long as it is maintained at a constant temperature, for example, room temperature, as indicated by the dashed-dotted line in FIG. The light transmitted through the sample flow cell 19 and the reference cell 23 is selectively irradiated to the photodetector 25 by either light by the optical path switching unit 24. In addition, the light source 21, the optical branching section 22, the optical path switching section 24, and the photodetector 25 correspond to the transmission light intensity detecting means in the present invention. Further, light sources of the same intensity may be arranged in each of the sample flow cell 19 and the reference cell 23, and photodetectors having the same sensitivity may be arranged. In such a configuration, the optical branch 22 and the optical path switching section 24 are not necessary.

A signal related to the transmitted light intensity detected by the photodetector 25 is given to the density controller 30. Functionally classifying the concentration control section 3, the transmitted light intensity measuring section 31, the temperature control section 32, the calibration curve data measuring section 33, the calibration curve data storage section 34, the correction coefficient calculation section 35, the transmittance It is divided into a calculation unit 36, a feedback control unit 37, a supply amount control unit 38, and an optical path switching control unit 39. The transmitted light intensity measuring unit 31 corresponds to the transmitted light intensity measuring unit according to the present invention, and the temperature adjusting unit 32, the heater 13, and the temperature sensor 15 use the temperature adjusting unit, and the calibration curve data measuring unit 33 ) Is the calibration curve data measuring means, the calibration curve data storage section 34 is the calibration curve data storage means, the correction coefficient calculation unit 35 is the correction coefficient calculation means, the transmittance calculation unit 36 is the transmittance calculation means, the feedback control unit Reference numeral 37 corresponds to a feedback control means, respectively. The supply amount control unit 38 and the flow control valve (V _1, V ₂₎ corresponds to the feed rate control means in the present invention.

The transmitted light intensity measuring unit 31 switches the optical path switching unit 24 to the sample flow cell 19 through the optical path switching control unit 39, and prepares the " standard processing " Liquid through the sample flow cell 19 while being circulated to the processing liquid supply pipe 9 and prepared at a predetermined temperature by the temperature controller 32, the heater 13, and the temperature sensor 15. Measure the standard transmitted light intensity I _R ). At the same time, the optical path switching unit 24 is switched to the reference cell 23 through the optical path switching control unit 39 to measure the transmitted light intensity (reference transmitted light intensity I _v ). Each of the measured transmitted light intensities is sent to the correction coefficient calculation unit 35 or the transmittance calculation unit 36.

Further, the transmission light intensity measuring unit 31 is adjusted to the same temperature as that of the reference treatment liquid, and has passed through the sample flow cell 19 a treatment liquid having the same concentration as that of the reference treatment liquid. Through 39), the optical path switching unit 24 is switched to the sample flow cell 19 to measure the transmitted light intensity (sample transmitted light intensity Is). At the same time, the transmitted light intensity measuring unit 31 switches the light path switching unit 24 toward the reference cell 23 through the optical path switching control unit 39 to measure the transmitted light intensity (reference transmitted light intensity I _v ). These measured transmission angles of light are sent to the transmittance calculation unit 36.

The calibration curve data measuring unit 33 distributes only the solvent (pure water in this embodiment) included in the processing liquid to the sample flow cell 19 to change the temperature of the pure water to the temperature control unit 32 while transmitting light intensity at each temperature. Is obtained from the transmitted light intensity measuring unit 31. The calibration curve data indicating the relationship between the temperature of the solvent and the transmitted light intensity is stored in the calibration curve data storage 34.

The correction coefficient calculating unit 35 selects the reference processing liquid or the processing liquid from the temperature of the processing liquid used for processing the reference processing liquid or the wafer and the solvent included in the processing liquid from the calibration curve data stored in the calibration curve data storage 34. and calculates a predicted transmission light intensity (I _F) correction coefficient (K) from the ratio of the reference transmitted light intensity (I _v) and the predicted transmission light intensity (I _F), obtain the corresponding to the reference transmitted light intensity in the case when the temperature of .

The transmittance calculation unit 36 transmits the reference treatment liquid (reference transmittance T _R ) at the reference transmittance intensity I _R , the reference transmittance intensity I _v , and the correction coefficient K calculated by the correction coefficient calculation unit 35. At the same time, it has a function of calculating the transmittance (sample transmittance T _s ) of the processing liquid from the sample transmitted light intensity (I _s ), the reference transmit light intensity (I _v ), and the correction coefficient (K).

The feedback control unit 37 receives the reference transmittance T _R and the sample transmittance Ts from the transmittance calculation unit 36, and transmits a control signal according to the difference to the supply amount control unit 38. Receiving this, the supply amount control unit 38 properly adjusts the flow rate adjusting valve V ₁ of the pure water supply pipe 3 or the flow rate adjusting valve V ₂ of the chemical liquid supply pipe 7 to adjust the flow rate of the processing liquid used for the processing of the wafer. Has the function to adjust the concentration.

Next, reference setting processing performed in advance will be described with reference to the flowchart in FIG.

This process corresponds to the standard setting process in the present invention.

In step P1, only the pure water is supplied to the processing tank body 1a and the overflow part 1b of the processing tank 1 in the pure water supply pipe 3, and circulated by the pump 11 at the same time. . Next, the calibration data measuring unit 33 controls the temperature adjusting unit 32 to change the temperature for a predetermined temperature range to obtain the transmission light intensity of pure water (solvent) at each temperature from the transmission light intensity measuring unit 31 ( Step P2). In step P3, the calibration curve data indicating the relationship between the temperature of pure water and the transmitted light intensity measured in step P2 is stored in the calibration curve data storage 34. An example of this stored calibration curve data is shown in FIG. In the example of FIG. 3, as described later, calibration curve data obtained by dividing light transmitted through the sample flow cell 19 into ultraviolet light (wavelength 290 nm) and infrared light (wavelength 2210 nm) is shown.

In the drawings, the horizontal axis represents pure water temperature, and the vertical axis represents transmitted light intensity (relative transmitted light intensity) of each of ultraviolet light and infrared light. As is clear from the figure, it is a graph in which the right side of which the transmitted light intensity increases, such as temperature of ultraviolet light and infrared light, increases.

In step P4, the processing liquid is prepared at a predetermined concentration (c) by a reference processing liquid adjusting device (not shown). This treatment liquid is referred to as the reference treatment liquid. After discharging the pure water supplied in step P1, this reference treatment liquid is supplied to the pump 11 while supplying it to the extent to which it stays in the treatment tank main body 1a and the overflow part 1b of the treatment tank 1, Is circulated. In addition, it is heated by the temperature control part 32, the heater 13, and the temperature sensor 15 so that it may become predetermined temperature (t _e ). In this state, the transmitted light intensity measuring unit 31 switches the optical path switching unit 24 toward the sample flow cell 19 through the optical path switching control unit 39 to measure the transmitted light intensity, and the measurement result is referred to as the reference transmitted light intensity (I). _R ) is sent to the transmittance calculation unit 36. The temperature control part 32 measures the temperature of the reference processing liquid at the output of the temperature sensor 15, and sends this measurement temperature t _m (almost equal to the predetermined temperature t _e ) to the correction coefficient calculation part 35. (Step P5). In step P6, the transmitted light intensity measuring unit 31 switches the optical path switching unit 24 toward the reference cell 23, and then measures the transmitted light intensity and transmits it to the transmittance calculation unit 36 as the reference transmitted light intensity I _v . send.

In step P7, the correction coefficient K is obtained by the correction coefficient calculating unit 35. The correction coefficient calculation unit 35 first inputs the measurement temperature t _m of the reference processing liquid to the calibration curve data storage unit 34. The calibration curve data storage section 34 calculates the transmitted light intensity of pure water corresponding to the measurement temperature t _m from the stored calibration curve data and returns to the correction coefficient calculation section 35. This transmitted light intensity corresponds to the transmitted light intensity when the temperature of the pure water filled in the reference cell 23 is the measurement temperature t _m of the reference treatment liquid, which is referred to as the predicted transmitted light intensity I _F. The correction coefficient export unit 35 calculates the correction coefficient K (= I _v / I _F ) at the ratio between the reference transmission light intensity I _v and the predicted transmission light intensity I _F measured at step P6.

In step P8, the transmittance is calculated from the reference transmission light intensity I _R measured in step P5, the reference transmission light intensity I _v measured in step P6, and the correction coefficient K calculated in step P7. The unit 36 calculates the transmittance of the reference treatment liquid. This transmittance is the transmittance at the measurement temperature t _m (nearly equal to the predetermined temperature t _e ) of the reference treatment liquid, and this is referred to as the reference transmittance T _R (= K · I _R / I _v ). The calculated reference transmittance T _R is maintained in the transmittance calculation unit 36.

In this way, the reference transmittance (I _v ) is corrected by the measurement temperature (t _m ) of the reference treatment solution to obtain the reference transmittance (T _R ), so that the temperature of the reference treatment solution is not cooled to the temperature of pure water filled in the reference cell. In this state, the reference transmittance (T _R ) can be accurately obtained.

Next, the feedback control process will be described with reference to FIG.

This feedback control process corresponds to the feedback control process in the present invention.

In step S1, the supply amount control unit 38 controls the flow rate regulating valve V ₁ of pure water and the flow rate regulating valve V ₂ of chemical liquid to treat the chemical liquid and the pure water at a ratio which becomes almost a predetermined temperature (c). It supplies to (1).

Then, after the treatment liquid is stored up to the overflow portion 1b, the temperature is adjusted so that the temperature controller 32 becomes the predetermined temperature t _e while circulating the treatment liquid by the pump 11 to the treatment liquid supply pipe 9. Adjust

In step S2, the transmitted light intensity measuring unit 31 switches the light path switching unit 24 toward the sample flow cell 19 by the transmitted light intensity measuring unit 31, and the transmitted light intensity measuring unit 31 measures the transmitted light intensity of the sample flow cell 19. , also outputs a transmission light intensity in the calculation unit 36 the transmittance as a sample transmission light intensity (I _s) and at the same time, temperature control unit measures the temperature by 32 to measure the temperature of the treatment liquid (t _m ') (approximately a predetermined temperature t equal to t _e ) is sent to the correction coefficient calculation unit 35.

Next, the transmitted light intensity measuring unit 31 switches the optical path switching unit 24 toward the reference cell 23, measures the reference transmitted light intensity I _v , and sends it to the correction coefficient calculating unit 35 (step S3).

In step S4, the correction coefficient K is calculated by the correction coefficient calculating unit 35. The correction coefficient calculator 35 inputs the calibration temperature data storage 34 to the calibration curve data storage 34 by inputting the measured temperature t _m ′ of the processing liquid (almost equal to the predetermined temperature t _e measured at step S2). ) Calculates the transmitted light intensity corresponding to the measurement temperature t _m ′ from the calibration curve data and returns to the correction coefficient calculation unit 35. This transmitted light intensity corresponds to the transmitted light intensity when the temperature of the pure water filled in the reference cell 23 is the measurement temperature t _m 'of the reference treatment liquid, and is referred to as the predicted transmitted light intensity I _F. The correction coefficient K (= I _v / I _F ) is calculated from the ratio between the reference transmitted light intensity I _v and the predicted transmitted light intensity I _F measured in step S3.

In step S5, the sample transmittance T _s (= K · I _s / I _v ) is calculated from the sample transmit light intensity I _s , the reference transmit light intensity I _v , and the correction coefficient K.

In this way, the sample transmittance (T _s ) is obtained by correcting the reference transmission light intensity (I _v ) with the temperature of the processing liquid (t _m '). Thus, the temperature of the pure water filled in the reference cell is used for processing the wafer. The sample transmittance (T _s ) can be accurately obtained without cooling to.

In step S6, the reference transmittance T _R and the sample transmittance T _s are compared and returned to step S2 in the same case (the concentration of the processing liquid actually used for the processing of the wafer is the same as the reference processing liquid). . On the other hand, if it is not the same (the concentration is different from the reference treatment liquid), the process of step S7 is performed. In step S7, either the chemical liquid or the pure water is replenished with the treatment liquid depending on the difference between the reference transmittance T _R and the sample transmittance T _s . Specifically, in the transmittance calculation unit 36, the above-mentioned transmittances T _R and T _s are input to the feedback control unit 37 to output a control signal to the supply amount control unit 38 according to this difference. The supply amount control unit 38 adjusts only the flow rate adjusting valve V ₁ or the flow rate adjusting valve V ₂ in accordance with the control signal. The process then returns to step S2 to repeat this process.

By repeating these steps (S2 to S7), the difference between the reference transmittance (T _R ) related to the concentration of the substrate processing liquid and the sample transmittance (T _s ) regarding the concentration of the processing liquid actually used for processing the wafer is obtained. Therefore, the control is performed so that the concentration of the processing liquid actually used for the processing of the wafer becomes a predetermined value. In other words, the density control is performed based on the difference in transmittance associated with this without calculating the concentration, thereby reducing the load on the calculation process. In addition, since the influence of temperature dependence is eliminated, the concentration of the processing liquid actually used for the processing of the wafer can be matched with the concentration of the reference processing liquid accurately and responsibly.

B. Example 2 Device (Example of Substrate Processing Apparatus Using Second Invention Method)

5 is a block diagram showing a schematic configuration of a substrate processing apparatus according to a second embodiment using the second invention method. In the drawings, the same reference numerals as those in the first embodiment are the same as those in the first embodiment, and detailed description thereof will be omitted.

As in the first embodiment, light from a light source 21 such as a halogen lamp is diverged in two directions by the light splitting section 22, and one side of the sample flow cell 19 is irradiated. In the first embodiment, the other light is irradiated to the reference cell 23, but in this embodiment, the filter F is configured to be irradiated. This filter F is for reducing the incident light from the light source 21, and is comprised by having predetermined | prescribed photosensitivity. The value of the photosensitivity is preferably such that the level is close to the intensity of light transmitted through the sample flow cell 19. In addition, this filter F is provided in order to reduce an error at the time of a calculation mentioned later, and when the influence of an error is small, the optical intensity of the light source 22 is directly cut | disconnected without installing the filter F. You may introduce into the affected part 24. In addition, the intensity of the light transmitted through the filter F and the intensity of the light of the light source 21 when the filter F is not provided are related to the light intensity of the light source 21 and thus correspond to the light intensity associated with the light source.

The light passing through the sample flow cell 19 or passing through the filter F is converted into signals according to their light intensities by the photodetector 25 and is given to the concentration controller 30.

The "reference treatment liquid" prepared in advance by a reference treatment liquid preparation device (not shown) is distributed to the treatment liquid supply pipe (9) by the temperature control part (32), the heater (13), and the temperature sensor (15). In the state of adjusting to a predetermined temperature, the transmitted light intensity measuring unit 31 measures the transmitted light intensity (standard transmitted light intensity I _R ) through the sample flow cell 19. As shown in the measurement, the transmitted light intensity measuring unit 31 switches the light path switching unit 24 toward the filter F through the light path switching control unit 39 to reduce the light source intensity I _o 'corresponding to the light source related light intensity. Measure Further, the reference treatment liquid circulated in the treatment liquid supply pipe 9 is discharged through a drain (not shown), and the pure water is circulated through the treatment liquid supply pipe 9 by adjusting the flow control valve V ₁ . At this time, the pure water is maintained at a constant temperature by the temperature control unit 32, the heater 13 and the temperature sensor 15. In this state, the transmitted light intensity measuring unit 31 measures the transmitted light intensity (reference transmitted light intensity I _v ) through the sample flow cell 19 and at the same time, the optical path switching unit 24 through the optical path switching control unit 39. ) Is switched to the filter (F) to measure the reduced light intensity (I _o ').

In addition, the transmission light intensity measuring unit 31 transmits the transmitted light intensity (sample) while adjusting the same temperature as the reference processing liquid and circulating the processing liquid having the same concentration as the reference processing liquid in the sample flow cell 19. and at the same time it measures the light intensity I _s-situ), by switching the optical path switching section (24) towards the filter (F) to measure the reduced source light intensity (I _o '). In this way, each light intensity measured by the transmitted light intensity measuring unit 31 is given to the transmittance calculation unit 36 as a ratio of the angle transmitted light intensity / angle low light source light intensity. Here, the ratio between the reference transmission intensity (I _R ) and the reduced light source intensity (I _o ') is defined as the reference transmission intensity ratio (R _R ) (= I _R / I _o '), and the reference transmission intensity (I _v ) The ratio between the reduced light source intensity (I _o ') is referred to as the reference transmission intensity ratio (R _v ) (= I _v / I _o '), and the ratio between the sample transmitted light intensity (I _s ) and the reduced light source intensity (I _o '). Is the sample transmission light intensity ratio (R _s ) (= I _s / I _o ').

The calibration curve data section 33 distributes only pure water to the sample flow cell 19 to obtain the transmitted light intensity at each temperature while changing the temperature of the pure water in the temperature control unit 32, and at the same time, the optical path The switching section 24 is switched to the filter F to obtain the low intensity light intensity in the transmitted light intensity measurement section 31.

The calibration curve data storage section 34 stores calibration curve data indicating a relationship between the temperature thus measured and the transmission light intensity ratio (transmission light intensity / low light source light intensity).

The correction coefficient calculation unit 35 is based on the pure water circulating in the sample flow cell 19 based on the temperature of the processing liquid used for the processing of the reference processing liquid or the wafer and the calibration curve data stored in the calibration curve data storage 34. Equivalent to the reference transmission light intensity ratio (I _F / T _o ') which is the ratio between the reference transmission light intensity (I _F ) and the reduced light source light intensity (Io') at the same temperature as the processing liquid or the processing liquid used for processing the wafer. The predicted transmission intensity ratio (R _F ) is obtained to calculate the correction coefficient (K) from the ratio between the reference transmission intensity ratio (R _v ) and the predicted transmission intensity (R _F ).

The transmittance calculation unit 36 calculates the transmittance (reference transmittance T _R ) of the reference treatment liquid from the reference transmittance intensity ratio R _R , the reference transmittance intensity ratio R _v , and the correction coefficient K, and transmits the sample transmittance intensity. The transmittance (sample transmittance T _s ) of the processing liquid actually used for the processing of the wafer is calculated from the ratio (R _s ), the reference transmittance intensity ratio (R _v ), and the correction coefficient (K).

The feedback control unit 37 inputs the reference transmittance T _R and the sample transmittance T _s in the transmittance calculation unit 36, and outputs a control signal according to the difference to the supply amount control unit 38. The supply amount control unit 38 adjusts the concentration of the treatment liquid by appropriately adjusting the flow rate control valve V ₁ of the pure water supply pipe 3 or the flow rate control valve V ₂ of the chemical liquid supply pipe 7.

Next, reference setting processing performed in advance (corresponding to the reference setting process) will be described with reference to the flowchart in FIG.

In step P1, only the pure water is supplied to the pure water supply pipe 3 to the extent to which the pure water stays in the treatment tank main body 1a and the overflow part 1b of the treatment tank 1, and is circulated by the pump 11 at the same time. Next, the calibration curve date measuring unit 33 controls the temperature adjusting unit 32 to change the temperature for a predetermined temperature range, thereby obtaining the transmitted light intensity at each temperature from the transmitted light intensity measuring unit 31, The affected part 24 is switched to the filter F to obtain the reduced light source light intensity at each temperature in the transmitted light intensity measuring unit 31 (step P2).

In step P3, calibration curve data indicating the relationship between the temperature measured in step P2 and the transmission light intensity ratio (transmission light intensity / low light source light intensity) is stored in the calibration line data storage 34. An example of this stored calibration curve data is shown in FIG. 7 shows calibration curve data obtained by dividing light transmitted through the sample flow cell 19 into ultraviolet light and infrared light as in the first embodiment.

Step P4 prepares a reference treatment liquid as in the first embodiment and heats it to a predetermined temperature t _e .

In this state, the transmitted light intensity measuring unit 31 measures the transmitted light intensity and outputs it to the transmittance calculation unit 36 as the reference transmitted light intensity I _R , and simultaneously switches the light path switching unit 24 toward the filter F. The reduced light source light intensity I _o 'is measured and output to the transmittance calculation unit 36. In addition, the temperature controller 32 measures the temperature of the reference processing liquid and outputs the measurement temperature t _m (nearly equal to the predetermined temperature t _e ) to the correction coefficient calculation unit 35 (step P5).

In step P6, the reference processing liquid circulated in the processing liquid supply pipe 9 is discharged through a drain (not shown), and the pure water prepared at a predetermined temperature through the temperature control unit 32 is treated. Distribution to. That is, pure water maintained at a constant temperature is passed through the sample flow cell 19.

In step P7, the transmitted light intensity measuring unit 31 measures the transmitted light intensity in the case of switching the optical path switching unit 24 toward the sample flow cell 19 and in the case of switching to the filter F side, respectively. (I _v ) and outputted to the transmittance calculation unit 36 as reduced light source light intensity I _o '.

In step P8, the correction coefficient K is obtained. The correction coefficient calculation unit 35 gives the calibration curve data storage 34 the measurement temperature t _m of the reference processing liquid (measured in step P5), and the calibration curve data storage 34 provides the calibration curve data ((transmission intensity / The transmission light intensity ratio (transmission light intensity / low light source light intensity) corresponding to the measurement temperature t _m at the reduced light source light intensity) -temperature) is obtained and output to the correction coefficient calculation unit 35. This transmission light intensity ratio corresponds to the transmission light intensity ratio obtained when the temperature of the pure water circulated in the sample flow cell 19 is the measurement temperature t _m of the reference treatment liquid, and this is the estimated transmission light intensity ratio R _F ( Transmitted light intensity T _F / Low light intensity I _o '). And the correction factor K (= I _v ) at the ratio between the reference transmittance intensity ratio (Rv) (Iv / Io ') and the estimated transmittance intensity ratio (R _F ) (I _F / I _o ') (measured in step P7). / I _F ) This correction coefficient K cancels the reduced light source light intensity I _o 'of the above ratio and becomes a ratio of the reference transmitted light intensity I _v and the predicted transmitted light intensity I _F as in the first embodiment.

In step P9, the reference transmission intensity ratio R _R (I _R / I _o ') measured in step P5 and the reference transmission intensity ratio R _v measured in step P7 (I _v / I _o) And the correction coefficient K calculated in step P8, the transmittance calculation unit 36 calculates the transmittance of the reference treatment liquid. This transmittance is the transmittance at the measurement temperature t _m (nearly equal to the predetermined temperature t _e ) of the reference treatment liquid, and this is the reference transmittance T _R (= KR _R / R _v ) = K · (I _R Let / I _o ') / (I _v / I _o ') = K · I _R / I _v = This reference transmittance T _R is the same as that of the first embodiment, and is similarly maintained in the transmittance calculation unit 36.

In this way, since the reference transmittance intensity ratio (R _v ) different from the temperature of the reference treatment solution is corrected by the measurement temperature (t _m ) of the reference treatment solution, the reference transmittance (T _R ) is obtained. The reference transmittance (T _R ) can be accurately calculated in the state of not cooling to the temperature of the pure water circulated in the cell. According to the present embodiment, the reference transmittance T _R can be obtained without using the reference cell 23 as in the first embodiment. In addition, since the reduced light source light intensity related to the light intensity of the light source is measured together with each transmitted light intensity, and each value is calculated from these ratios, even if there is a variation in the light intensity of the light source 21, the ratio is almost constant, so The reference transmittance (T _R ) can be accurately calculated without any change.

Next, with reference to FIG. 8 (corresponding to the feedback control process), the feedback control process will be described.

In step S1, the pure water maintained at a constant temperature is circulated to the sample flow cell 19 as in step P6 of the reference setting processing (shown in FIG. 6). Then, as in the step P7 of the reference setting process, the transmitted light intensity measuring unit 31 measures the reference transmitted light intensity I _v and the reduced light source light intensity I _o 'in this state (step S21). Is output to the correction coefficient calculation unit 35 as a reference transmission light intensity ratio R _v (= I _v / I _o ').

In step S3, the chemical liquid and the pure water are supplied to the treatment tank 1 to the temperature control unit 32 so as to have a predetermined concentration (c) in the same manner as in step S1 (Fig. 4) described in the first embodiment. The temperature is adjusted so that the temperature becomes the predetermined temperature t _e .

In step S4, the transmitted light intensity measuring unit 31 measures the transmitted light intensity in the case where the optical path switching unit 24 switches to the sample flow cell 19 and when the optical path switching unit 24 switches to the filter F side. (I _s), reducing the light source light and outputs in Figure (I _o ') of the sample transmitted light intensity ratio (R _s) (= I _s / I _o') calculating a correction coefficient unit 35 as.

In addition, the temperature control unit 32 measures the temperature of the processing liquid and outputs it to the correction coefficient calculation unit 35 as the measurement temperature t _m '(almost equal to the predetermined temperature t _e ).

In step S5, the correction coefficient K is obtained. The correction coefficient calculation unit 35 inputs the measurement temperature t _m ′ of the processing liquid (nearly equal to the predetermined temperature t _e measured in step S4) to the calibration curve data storage 34, and then the calibration curve data storage 34. Obtains the transmission light intensity ratio corresponding to the measurement temperature t _m 'from the calibration curve data and outputs it to the correction coefficient calculation unit 35. This transmitted light intensity ratio corresponds to the transmitted light intensity when the temperature of the pure water circulated to the sample flow cell 19 at step S1 is the measured temperature t _m 'of the processing liquid, and this is the predicted transmitted light intensity (R _F). ) (= I _F / I _o '). And step a reference transmitted light intensity ratio measured in _{(S2) (R v) (} = I v / I o ') and a prediction transmitted light intensity ratio (R _F) in ratio correction coefficient (K) with (= I _v / I _F ) Is calculated.

In step S6, the sample transmittance ratio (R _s ), the reference transmittance intensity ratio (R _v ), and the sample transmittance (T _s ) at the correction coefficient (K) (= K · R _s / R _v = K · (I _s) / I _o ') / (I _v / I _o ') = K · I _s / I _v ). This sample transmittance T _s is obtained in the same manner as in the first embodiment, and is similarly retained in the transmittance calculation unit 36. Thus, the sample transmittance (T _s ) is obtained by correcting the reference transmission intensity ratio (R _v ) by the temperature of the treatment liquid (t _m '), so that the temperature of the treatment liquid is passed up to the temperature of pure water circulated in the sample flow cell (19). The sample transmittance (T _s ) can be accurately determined in the same state without cooling. In addition, since the reduced light source light intensity related to the light intensity of the light source, such as the angle transmitted light intensity, is measured and the angle value is calculated from this ratio, even if there is a variation in the light intensity of the light source 21, the angle ratio is almost unchanged. As a result, the sample transmittance (T _s ) can be accurately obtained.

In step S7, as in the first embodiment, when the reference transmittance T _R and the sample transmittance T _s are compared and are the same (when the concentration of the treatment liquid actually used for the treatment of the wafer is the same as the reference treatment liquid), Return to the recess S4. On the other hand, when the transmissivity (T _R , T _s ) is not the same (when the concentration of the processing liquid actually used for the processing of the wafer is different from the reference processing liquid), the process of step S8 is performed. That is, depending on the difference between the transmittance (T _R , T _s ), either the chemical liquid or the pure water is replenished with the treatment liquid. Then, the process returns to step S4 and the processes of steps S4 to S8 are repeated.

By repeating these steps S4 to S8, the concentration of the processing liquid actually used for the processing of the wafer according to the difference from the positive transmittance T _R , T _s related to the concentration as in the first embodiment Is precisely controlled and the same effect can be obtained. The reference transmittance (T _R ) and the sample transmittance (T _s ) are calculated based on the ratio of the reduced light source light intensity (I _o '), which is the light intensity associated with the light source, respectively. Can be calculated. Therefore, concentration control can be performed correctly over a long period of time.

In addition, in the above-described first embodiment, the light source related light intensity related to the light intensity of the light source 21 is not measured. However, a means for measuring the light intensity of the light source 21 is provided in the reference cell 23 or Means for measuring the luminous intensity of the light source 21 in the filter F (or directly without dimming with the filter F) for reducing the light of the light source 21 as in the second embodiment, apart from the reference cell 23. May be installed. Then, the optical path switching section 24 serves as a branching section for dividing the optical branch section 22 in two or three directions as the switching section of two inputs or three inputs, for example, as shown in the second embodiment. (Transmitted light intensity / low light source light intensity)-The angle transmittance may be calculated as the ratio of the angle transmitted light intensity as the temperature to the reduced light source intensity as temperature.

In addition, the present invention is not limited to the substrate processing apparatus shown in FIGS. 1 (first embodiment apparatus) and FIG. 5 (second example apparatus), and is also applicable to a substrate processing apparatus as shown in FIG. Can be. In the apparatus of the first and second embodiments shown in FIGS. 1 and 5, the processing liquid is configured to circulate the processing liquid supply pipe 9, but in the substrate processing apparatus shown in FIG. It is.

Pure water is supplied to the processing liquid supply pipe 9 'through a flow control valve V ₁ . In addition, the chemical liquid is supplied from the plurality of chemical liquid tanks 5 _{1 to} 5 ₃ through the flow control valves V _{2 to} V ₄ and the chemical liquid pipings 7 ₁ to 7 ₃ to prepare the processing liquid at a predetermined mixing ratio. The processing liquid after preparation is adjusted to a predetermined temperature by the heater 13 and the temperature sensor 15 arranged in the processing liquid supply pipe 9 '. The processing liquid adjusted to the predetermined concentration and temperature is treated as a processing tank (1). It is configured to supply to. Also in such a structure, the density control part 30 mentioned above enables accurate and responsive density control.

In addition, it is necessary to measure the transmitted light intensity in a plurality of wavelength bands depending on the treatment liquid. For example, in the treatment liquid consisting of ammonia and hydrogen peroxide, the rate of change of the transmitted light intensity due to the concentration of ammonia in the infrared wavelength band is large, and the rate of change of the transmitted light intensity due to the concentration of hydrogen peroxide in the ultraviolet wavelength band is large. Therefore, in order to measure the transmitted light intensity of such a processing liquid and to control the concentration based on this, it is preferable to configure a photodetector as shown in FIG.

That is, the light transmitted through the sample flow cell 19 is separated into ultraviolet light (UV) and infrared light (IR) by the optical path switching unit 24 ′, and the ultraviolet light detector 25b ₁ and the infrared light detector 25b2, respectively. ) Is incident. In order to separate ultraviolet light and infrared light, it is performed by the combination of a dichromic mirror, an infrared bandpass filter, and an infrared bandpass filter. The optical path switching unit 24 'also has an optical path switching function between the sample flow cell 19 and the reference cell 23 (filter F) as in the configuration of FIG.

In this case, calibration curve data are measured for ultraviolet light and infrared light, respectively. In addition, the reference transmittance (1 _{R (UV)} , I _{R (IR)} ), reference transmission intensity (I _{v (UV)} , I _{v (IR)} , ...) and the like are measured and the reference transmittance (T _{R (UV) )} , T _{R (IR)} ), and the sample transmittance (T _{s (UV)} , T _{s (IR)} ) to calculate the reference transmittance (T _{R (UV)} ) and the sample transmittance (T _{s (UV)} ) for ultraviolet light. Depending on the difference between and supplemented with hydrogen peroxide in the treatment liquid (or pure water in the treatment liquid ₎ , ammonia was added in accordance with the difference between the reference transmittance (T _{R (IR)} ) and the sample transmittance (T _{s (IR)} ) for infrared light. The treatment liquid may be replenished (or pure water may be replenished).

In addition, in order to prepare the concentration of the treatment liquid, the treatment liquid is supplemented with a chemical liquid or pure water. Alternatively, the treatment liquid may be changed so that a corresponding gas is completely dissolved in the treatment liquid. For example, when the treatment liquid contains hydrogen chloride, hydrogen chloride gas is replenished with the treatment liquid. In this way, the amount of the processing liquid does not increase by replenishing the processing liquid with gas equivalent to the chemical liquid.

Incidentally, in the first and second embodiments, pure water is used as an example and explained, but the present invention is not limited thereto. For example, in the washing | cleaning process by an organic solvent, it is possible to use a solvent (for example, acetone, isopropyl alcohol, etc.) suitably according to the process as a solvent.

C. Examples of flow cell for transmission light measurement preferably used in the above devices

The flow cell for transmitting light measurement constituting the sample flow cell and the reference cell included in each of the above-described example apparatuses generally includes a pair of light transmitting portions formed of quartz or sapphire (Al ₂ O ₃ ) at predetermined intervals (cell length). It is arranged to face each other, and irradiates light from one side of the light transmitting portion to the fluid to be measured which flows between these light transmitting portions, and measures the light intensity output from the other side of the light transmitting portion.

However, the flow cell for transmission light measurement having such a configuration has the following problems.

In other words, when the fluid to be treated (treatment liquid) contains a highly corrosive chemical liquid such as hydrofluoric acid (HF), the surface of quartz or sapphire, which is a material of the light transmitting portion, is eroded. Then, the predetermined interval (cell length) of the light transmissive portions that are disposed to face each other due to the erosion is expanded and shifted over time. As a result, there exists a problem that the light intensity which permeate | transmitted the to-be-measured fluid which flows between them will gradually fall and displace accordingly.

In addition, in the case where the light transmitting portion is formed of sapphire, in addition to the above problem, there is a problem that aluminum in sapphire elutes in the fluid under measurement due to corrosion by a chemical solution. In particular, in the processing apparatus of a semiconductor wafer, the concentration of the processing liquid as the fluid to be measured is adjusted and the cleaning liquid or surface treatment of the semiconductor wafer is performed by the processing liquid. Elution of a metal becomes a big problem since it causes the yield of a semiconductor to fall.

Hereinafter, an embodiment of a transmission light measuring flow cell that can stably maintain the cell length over time while preventing corrosion of the light transmitting portion and prevent contamination of the fluid under measurement will be described in detail.

FIG. 11 is an exploded perspective view of the flow cell for transmitting light measurement according to the embodiment, FIG. 12 is a horizontal sectional view thereof, and FIG. 13 is a longitudinal sectional view thereof.

The transmitted light measuring flow cell (sample flow cell) 19 according to the present embodiment includes frames 41a and 41b that can be divided up and down in communication with the fluid supply pipe 9 through which the fluid to be measured (processing liquid) flows. Doing. The frames 41a and 41b are formed of, for example, a fluorine resin, and through holes 42 are formed in the center of each of the frames 41a and 41b to allow light to pass therethrough. The 0 ring 43 is inserted around the circumference, and a pair of light transmitting portions 44a and 44b in the form of a disk are arranged thereon, and these light transmitting portions 44a and 44b have a wavelength of light that is irradiated. Therefore, it is formed of a suitable light-transmissive material, and in particular, when the fluid to be measured contains a highly corrosive chemical liquid such as hydrofluoric acid (HF), light-transmitting material such as sapphire (Al ₂ O ₃ ) or quartz is employed. However, especially when the temperature of the fluid under measurement is high, a material having a low coefficient of thermal expansion such as quartz is employed.

Films 44a ₁ and 44b ₁ having corrosion resistance to the fluid to be measured are formed on the surface of the light transmitting portions 44a and 44b in contact with the fluid to be measured. The coatings 44a ₁ and 44b ₁ can be variously applied as long as they have corrosion resistance to the fluid to be measured. However, fluorine resins having corrosion resistance to various chemical liquids and excellent heat resistance are preferable. In this embodiment, FEP (tetrafluoroethylene-hexafluoropropylene copolymer (also called tetrafluoroethylene-hexafluoropropylene copolymer copolymer resin) film), which is a kind of fluorine resin, is used as the coatings 44a ₁ and 44b ₁ . Is adopted to form the coating films 44a ₁ and 44b ₁ . In addition, the FEP film uses an appropriate film thickness, for example, about 70 µm, so that the transmittance of irradiated light does not decrease to the extreme.

In this way, since the coatings 44a ₁ and 44b ₁ having corrosion resistance to the fluid to be measured are formed on the surfaces of the light transmitting parts 44a and 44b in contact with the fluid to be measured, corrosion of the light transmitting parts 44a and 44b can be prevented. Can be. Therefore, the material forming the light transmitting portions 44a and 44b can be prevented from eluting in the fluid under measurement, the cell length can be kept stable over time, and contamination of the fluid under measurement can be prevented. As a result, it is stable over time and the light intensity can be measured.

In the present embodiment, the light transmitting portions 44a and 44b face almost parallel to the axis of the fluid flow to be measured. Between the coating 44a ₁ of the light transmitting portion 44a and the coating 44b1 of the light transmitting portion 44b, four spacers 45 for setting them at a predetermined interval, that is, the cell length d, are provided. It is fitted. These spacers 45 are formed of the same FEP as the coating films 44a ₁ and 44b ₁ described above. The length of the spacer 45, that is, the cell length, is appropriately set according to the absorbance of the fluid to be measured, and is usually about 1 to 3 mm.

Moreover, around the light transmission parts 44a and 44b arrange | positioned at each frame 41a and 41b, the distribution groove 47 which branch-flows a part of the to-be-measured fluid which flows is provided, respectively. The cross-sectional area of the flow path of the fluid under measurement in the frames 41a and 41b is set to be substantially equal to the cross-sectional area of the flow path of the fluid supply pipe 9 connected thereto. The above-mentioned frames 41a and 41b are hermetically sealed with 0 rings (not shown) and screwed into a pair of cover plates 48 having an opening formed in the center thereof.

The flow cell for transmitting light measurement 19 in a related configuration irradiates light of a predetermined wavelength to one light transmitting portion 44b from the light source 21 while circulating a fluid to be measured, and the other light transmitting portion 44b. By measuring the light intensity output from the photodetector 25, it is possible to measure the transmitted light intensity of the fluid to be measured.

Since the transmitted light measuring flow cell 19 is prevented from corroding the light transmitting portions 44a and 44b, the cell length is unchanged over time, and it is stable over time, and thus the transmitted light intensity can be measured. As a result, the concentration of the fluid to be measured (semiconductor cleaning liquid) can be accurately adjusted in the wafer cleaning apparatus using the flow cell 19 for this transmitted light measurement.

Next, a description will be given of the case where the light transmitting portions 44a and 44b are formed of quartz having a diameter of 20 mm and a thickness of 1.5 mm, and various coatings 44a ₁ and 44b ₁ are formed on the surface to which the measurement fluid comes into contact with. . The film-forming surfaces of the light transmitting portions 44a and 44b are subjected to optical polishing. In the above description, there was only one transmitted light measuring flow cell 19. Here again, another transmitted light measuring flow cell (reference cell) is used for reference, and the transmitted light intensity measuring flow cell 19 for the transmitted light intensity is used. This is explained by the ratio of the transmitted light intensity, i.e., the transmittance. In addition, infrared light (IR) (wavelength 2210 nm) and ultraviolet light (UV) (290 nm) were used as irradiation light.

The material constituting the film is FEP and PFA (tetrafluoroethylene-per-fluoroalkylvinyl ether copolymer), which are a kind of fluorocarbon resin, and the film forming method will be described by application and compression.

The first sample ① is coated with PFA so as to have a film thickness of 80 to 140 μm, and the second sample ② is coated with PFA so as to have a film thickness of 15 to 20 μm. (3) The coating material was applied so as to have a film thickness of 65 to 85 mu m as FEP. In addition, as described above, the fourth sample ④ was made of a FEP film having a film thickness of 70 µm as described above. In addition, in the film formation by ordinary coating, in order to improve the adhesion strength between the light transmitting part and the film, a primer treatment is performed to blast the surface of the light transmitting part and to apply a priming agent. The factor is omitted. Only sample 4 is primed because the film forming barrier is compressed. In addition, in the film formation by application | coating, it is preferable to apply | coat so that a coating surface may be as uniform as possible, since the roughness of the surface of a coating by scattering scatters light and affects a transmittance | permeability.

As a reference for the comparison of these samples 1 to 4, the transmittance in the state where the light transmitting portions 44a and 44b of the transmission light measuring flow cell 19 are removed is adopted and the ratio of the transmittance of each sample 1 to 4 (transmission) Ratio). The above transmittances are measured for four different samples 1 to 4, and the average values of the specific transmittances are shown below as reference data of light-transmitting part (quartz only) without film. 14 shows a graph.

As is clear from these measurement results, it can be seen that in the sample (4), the specific transmittance is high for each of the infrared light (IR) and the ultraviolet light (UV), and the FEP film is suitable for the coating material and the compression is suitable for the film forming method. Therefore, it is suitable for the measurement of the transmission light intensity and the transmittance of the fluid to be measured having high absorbance.

In the present embodiment, FEP and PFA are used as the film forming materials, and as an example, various materials can be used as long as they are fluororesin. For example, PTFE (polytetrafluoroethylene), PVdF (polyvinylidene fluoride), PCTFE (polychlorotrifluoroethylene), EPE (tetrafluoroethylene-hexafluoropropyleneper-fluoroalkylvinyl Ether copolymer), ETFE (tetrafluoroethylene-ethylene copolymer), ECTFE (chlorotrifluoroethylene-ethylene copolymer), PVF (polyvinyl fluoride), etc. can be used. In addition, as long as the material has corrosion resistance to the fluid to be measured, various film forming materials such as polyethylene and polypropylene other than the above-mentioned fluororesin can be used.

In the present embodiment, quartz and sapphire are employed as the light transmitting part as an example, but various materials can be used as long as sufficient transmittance is obtained at the wavelength of the irradiation light.

D. Examples of optical systems for measuring transmission light preferably used in the above devices

1 and 5, the light source 21, the optical branch 22, the sample flow cell 19, the reference cell 23 (or the optical filter F), and the optical path switching unit (in the apparatus shown in FIGS. 24), a preferred embodiment of the optical system for measuring transmission light including the photodetector 25 and the like will be described below.

FIG. 15 is a diagram showing a schematic configuration of an embodiment of an optical system for measuring transmitted light intensity. In addition, although the example applied to the apparatus of 1st Example mentioned above is shown here, it is applicable also to apparatus of 2nd Example.

Light generated by the light source 21 is balanced light by the aiming lens 21a and is irradiated to the pair of condensing lenses 22a. One side of the irradiated light collected by the condenser lens 22a is incident on the optical fiber 22b and the other is incident on the optical fiber 22b. Light output from the end of the optical fiber 22b becomes parallel light by the aiming lens 19a and enters the sample flow cell 19. Light transmitted through the sample flow cell 19 is collected by the condenser lens 19b and incident on the optical fiber 19c. The transmitted light output from the optical fiber 19c becomes parallel light by the aiming lens 19d.

The other irradiated light collected by the condenser lens 22a is incident on the optical fiber 22b, and becomes a parallel light by the aiming lens 23a and is irradiated to the reference cell 23. Light passing through the reference cell 23 is collected by the condenser lens 23b and incident on the optical fiber 23c. The light output from the optical fiber 23c becomes parallel light by the aiming lens 23d.

The light transmitted through the sample flow cell 19 changes its direction by 90 degrees and enters the prism 9 by the reflection of the reflection mirror 19e arranged at the opposite position of the aiming lens 19d. The light transmitted through the reference cell 23 is incident on the prism P by changing the direction by 90 degrees by the reflecting mirror 23e arranged at the opposite position of the aiming lens 23d. The light reflected by the prism P is collected by the condenser lens 25a and incident on the photodetector 25.

The light selection shutter 24a is arranged between the aiming lenses 19d and 23d and the reflection mirrors 19e and 23e. The light selection shutter 24a is formed in a plate shape and is composed of a light shielding portion 24a1 and an opening portion 24a2 serving as a light transmitting portion. The light selection shutter 24a is alternated by the air cylinder 24b to irradiate the reflecting mirror 19e and the reflecting mirror 23e with light passing through the sample flow cell 19 and the reference cell 23 alternately. Reciprocate as shown by the arrow. The air cylinder 24b corresponding to the driving means is configured to contract and expand its operation shaft by the optical path switching control section 39 of the concentration control section 30. The optical path switching control section 39, the light selection shutter 24a (light shielding portion 24a, the opening portion 24a) and the air cylinder 24b correspond to the optical path switching means in the present invention.

In the configuration of the optical path switching section 24, the air cylinder 24b is contracted and the transmitted light of the sample flow cell 19 is incident on the photodetector 25, and the air cylinder 24b is extended to operate the reference cell ( The transmitted light of 23 is incident on the photodetector 25.

Next, with reference to FIG. 16, the density | concentration preparation process in the substrate processing apparatus using the optical system for measuring transmitted light as mentioned above is demonstrated. 16 is a timing chart showing the operation timing of the optical path switching control unit 39 and the measurement timing of the transmitted light intensity measuring unit 31. As shown in FIG.

After confirming that the temperature of the processing liquid has reached a predetermined temperature, the transmitted light intensity measuring unit 31 instructs the optical path switching control unit 39 to drive the light selection shutter 24. The optical path switching controller 39 performs the contracting operation of the air cylinder 24b only for a predetermined time t1, and performs the decompression operation for only a predetermined time t. As a result, the transmitted light of the sample flow cell 19 is irradiated to the detector 25 by the photodetector 25 only for t hours. The predetermined time t and t is, for example, one second.

The transmitted light intensity measuring unit 31 takes in the output signal of the photodetector 25 at an appropriate timing within the above t time and measures it as the sample transmitted light intensity I. The output signal of the photodetector 25 is taken at an appropriate timing within the above T time and measured as the reference transmitted light intensity. In this way, the irradiation light from the one light source 21 is branched to irradiate the transmitted light of the sample flow cell 19 and the reference cell 23 to one photodetector 25. Even if there is a variation in the sensitivity, the influence extends to both the reference transmission intensity and the sample transmission intensity. Therefore, there is little influence of the variation of these ratios, and it is possible to accurately prepare the concentration of the treatment liquid based on this ratio.

Here, the transmitted light intensity measuring unit 31 repeats the measurement of the sample transmitted light intensity (I) and the reference transmitted light intensity (I), and processes the transmitted light intensities measured sequentially as follows. First, the ratio (T) (= I / I) between the first sample transmission light intensity (I) and the reference transmission light intensity (I), respectively, is obtained, and the second sample transmission light intensity (Is2) and the first reference transmission light intensity (I) The ratio T (= I / I) is obtained and their average value T is obtained. Next, the ratio (T) between the second sample transmission intensity (I) and the first reference transmission intensity (I) and the ratio (T) of the second sample transmission intensity (I) and the reference transmission intensity (I), respectively (= I / I) Find the average value (T) with). This is done sequentially to find the moving average.

When this moving average T is calculated, this value is sent to the transmittance calculation unit 36.

Thus, the photodetector (25) calculates a moving average for the ratio between the sample transmission light intensity and the reference transmission light intensity in the relation of repeating small and large compared to the ideal state in which the sample transmission light intensity and the reference transmission light intensity are simultaneously measured. By suppressing the influence of the sensitivity fluctuation, the ratio between the sample transmitted light intensity (I) and the reference transmitted light intensity (I) can be obtained with high accuracy and close to an ideal state.

In addition, it is necessary to measure the transmitted light intensity in a plurality of wavelength bands depending on the treatment liquid.

For example, in the treatment liquid consisting of ammonia and hydrogen peroxide, the rate of change of the transmitted light intensity due to the concentration of ammonia in the infrared wavelength band is large, and the rate of change of the transmitted light intensity due to the concentration of hydrogen peroxide in the ultraviolet wavelength band is large. Therefore, it is preferable to configure the photodetector 25 as shown in FIG. 17 in order to measure the transmitted light intensity of such a processing liquid and to control the concentration based on this.

That is, the light transmitted through the sample flow cell 19 and the reference cell 23 is irradiated to the prism P. The dichroic mirror (H) is separated into ultraviolet light (UV) and light in the visible and infrared wavelength region (I). In addition, the wavelengths of the ultraviolet light and the infrared light are selected by the ultraviolet band pass filter F and the infrared band pass filter F, respectively, and the band pass through the condenser lens 25a1 and the condenser lens 25a, respectively. An ultraviolet photodetector 25b having a spectral sensitivity to a wavelength selected by a filter (for example, composed of a semiconductor device made of GaP or the like or an infrared photoelectric tube) and an infrared photodetector 25b having a spectral sensitivity (for example, For example, a semiconductor element composed of Pbs, GaAsP, or the like).

In this case, the sample transmitted light intensity (I, I) and the reference transmitted light intensity (I, I) are measured for ultraviolet light and infrared light, respectively. As described above, the ratio T of the first sample transmission intensity I and the reference transmission intensity I (= I / (R) and the first sample transmission intensity I and the reference transmission intensity I, respectively) The ratios are obtained for the ultraviolet light and the infrared light, respectively, as in the ratio (T) (= I / I) with respect to).

The optical path switching unit 24 may be configured as shown in FIG.

That is, the light selection plate 24a and the air cylinder 24b are formed by changing the light selection shutter 24a to form the light shielding portion 24a and the notch portion 24a serving as the light transmission portion in a disc shape at a predetermined ratio. It consists of the motor 24b 'which rotationally drives the optical selection disk 24' at a predetermined speed. For example, the optical path switching controller 39 rotates the motor 24b 'as shown in FIG. According to this, the transmitted light of the sample flow cell 19 and the transmitted light of the reference cell 23 are irradiated to the photodetector 23 only alternately for t time, and the irradiation interval is controlled to be t time. Then, the transmission light intensity I and the reference transmission light intensity I are measured by the transmission light intensity measuring unit 31 in synchronization with each irradiation timing. In this way, the time (t-t) which light does not irradiate to the photodetector 25 arises.

Therefore, it is possible to obtain the same effect as arranging chopping sectors for controlling the heat rise of the photodetector 25 by continuously irradiating light, and stably measuring the transmitted light intensity.

The optical path switching unit 24 may be arranged at any position as long as it is between the optical detector 25 and the optical detector 25. For example, the light source 21 may be arranged between the aiming lens 21a and the condenser lens 22a (see FIG. 15). In this case, the optical fibers 19c and 23c are preferably formed of two-branch type optical fibers as so-called multi-core bundles in which both the core and the clad of the positive fiber are welded at one end to emit light at one end. According to this structure, since the transmitted light of the sample flow cell 19 and the reference cell 23 is converged by this optical fiber, the structure for converging the transmitted light to one photodetector 25 is unnecessary.

The method for obtaining the sample transmission light intensity ratio and the like by the moving average method as described above can also be applied to the substrate processing apparatus as shown in FIG. For example, the case where the flow regulating valve v in FIG. 9 is opened is demonstrated. In this state, the chemical liquid in the chemical liquid tank 51 is mixed with pure water, and the processing liquid is circulated through the processing liquid supply pipe 9 '. At this time, based on the fluid information given to the transmitted light intensity measuring unit 31, the transmitted light intensity measuring unit 31 determines that the fluid circulated in the sample flow cell 19 is a processing liquid (sample fluid). Then, the output signal from the photodetector 25 is repeatedly measured at appropriate intervals as the sample transmission light intensity Is and processed as follows.

The first sample transmission light intensity (Is), the reference transmission light intensity (1a) and the ratio (T) (= Is / I) are obtained, and the second sample transmission light intensity (Is) and the ratio (T) of the reference transmission light intensity (I) ( = Is / I) is obtained and the average value T of these ratios is obtained. Hereinafter, the average value (T) of the ratio (T) of the second sample transmission light intensity (Is) and the reference transmission light intensity (I) and the ratio (T) of the third sample transmission light intensity (Is) and the reference transmission light intensity (I) is obtained. . This is done sequentially to find the moving average. Each time this moving average T is calculated, this value is sent to the transmittance calculation unit 36.

In the apparatus of the second embodiment shown in FIG. 5, the transmission light intensity and the reduced light source light are also obtained when the ratio between the transmission light intensity of the reference transmission intensity, the reference transmission intensity, or the sample transmission intensity and the corresponding reduction light intensity is respectively obtained. The intensity may be repeatedly detected and the reference transmission light intensity ratio reference transmission light intensity ratio and sample transmission light intensity fertilizer may be obtained by the moving average method as described above.

The present invention can be embodied in other specific forms without departing from the spirit or essence thereof, and therefore, reference should be made to the appended claims rather than the foregoing description as indicating the scope of the invention.

Claims (20)

The transmission light intensity of the processing liquid used for processing the substrate is measured by the first transmission light intensity measuring means, and the transmission light intensity of the solvent constituting the processing liquid is measured by the second transmission light intensity measuring means. A concentration control method for controlling the concentration of a treatment liquid based on a measurement result, comprising: (a) measuring the transmitted light intensity of only the solvent by a first transmitted light intensity measuring means while changing the temperature of the solvent constituting the treatment liquid; And storing the calibration curve data indicating the relationship between the solvent temperature and the transmitted light intensity, and (b) the first transmitted light intensity measuring means using the transmitted light intensity of the reference treatment liquid prepared at a predetermined concentration and temperature as the reference transmitted light intensity. (C) measuring the transmitted light intensity of the solvent by the second transmitted light intensity measuring means as the reference transmitted light intensity, and (d) Based on the stored calibration curve data, when the solvent is at the same temperature as the reference treatment solution, the estimated transmitted light intensity corresponding to the transmitted light intensity of the solvent to be measured by the second transmitted light intensity measuring means is calculated, and the reference transmitted light is calculated. Calculating a correction coefficient from a ratio between the intensity and the predicted transmission light intensity, (e) calculating the transmittance of the reference treatment liquid at the predetermined temperature as a reference transmittance at the reference transmission intensity and the reference transmission intensity and the correction coefficient; (F) measuring the transmitted light intensity of the processing liquid actually used for processing the substrate by the first transmitted light intensity measuring means as the sample transmitted light intensity, and (g) the sample transmitted light intensity. And calculating the transmittance of the treatment liquid as the sample transmittance from the reference transmittance intensity and the correction coefficient, and (h) the substrate according to the reference transmittance and the sample transmittance. A concentration control method which repeats a process of controlling the concentration of a treatment liquid to be actually used for the treatment of a process and a feedback control process so that the reference transmittance and the sample transmittance coincide. The method according to claim 1, wherein the reference transmittance intensity is measured by repeating the process of (c) before or after the process of (f), and after obtaining a correction coefficient from the ratio of this and the estimated transmittance intensity, Concentration control method to carry out the process. The method of claim 1, wherein the step (a) measures the transmitted light intensity at each temperature, and measures the light intensity related to the light intensity of the light source at each temperature to measure the transmitted light at each temperature. The ratio between the intensity and the light intensity associated with the light source (transmission intensity ratio) is stored as calibration curve data, and in each step of (b), (c), and (f), the measurement of each transmitted light intensity in each process is performed. And measuring the light intensity associated with the light source to obtain a ratio between each transmitted light intensity and each light intensity associated with each light source, and performing a calculation based on these ratios in each process. A substrate processing apparatus for processing a substrate by a processing liquid prepared at a predetermined concentration and temperature, comprising: a substrate storage means for storing a substrate to be processed and a processing liquid for processing a substrate stored in the substrate storage means; A processing liquid storage means, a chemical liquid supplying means for supplying a chemical liquid or a gas thereof to the processing liquid storage means, a solvent supply means for supplying a solvent constituting the processing liquid to the processing liquid storage means, and a processing liquid storage means Processing liquid supply means for supplying the processing liquid stored in the means to the substrate housed in the substrate storage means, first and second sample collecting means having light transmitting portions having the same optical path length, and in a predetermined concentration and temperature in advance; The transmission light intensity of the adjusted reference treatment liquid (reference transmission intensity) is measured using the first sampling means, and the transmission light intensity of the treatment liquid actually used to process the substrate (sample transmission intensity) ) Is a first transmission light intensity measuring means for measuring using a first sampling means, and a transmission light intensity (reference transmission light intensity of the solvent constituting the treatment liquid) is measured using a second sampling means. Calibration curve data indicating the relationship between the solvent temperature and the transmitted light intensity by measuring the transmitted light intensity of only the solvent while changing the temperature of the transmitted light intensity measuring means and the solvent constituting the treatment liquid using a first sampling means. A second transmission light intensity measuring means using a calibration sample data collecting means for collecting the sample and a second sampling means when the solvent is at the same temperature as the reference treatment liquid based on the temperature of the reference processing liquid and the collected calibration curve data. A correction factor that calculates a predicted transmitted light intensity corresponding to the transmitted light intensity in the case of measuring by using the formula and calculates a correction coefficient from the ratio between the reference transmitted light intensity and the predicted transmitted light intensity. Calculation means, a reference transmittance calculating means for calculating the transmittance of the reference treatment liquid at the predetermined temperature as a reference transmittance at the reference transmittance intensity and the reference transmittance intensity and the correction coefficient, and the sample transmittance intensity and the reference transmittance intensity and the correction coefficient A sample permeability calculation means for calculating the permeability of the liquid as a sample permeability, and a concentration for controlling the concentration of the processing liquid actually to be used for processing the substrate by controlling the chemical liquid supply means and the solvent supply means according to the standard permeability and the sample permeability. Substrate processing apparatus having a control means. 5. The substrate processing apparatus according to claim 4, wherein the concentration control means includes feedback control means for controlling the chemical liquid supply means and the solvent supply means according to the difference between the reference transmittance and the sample transmittance. 5. The measuring fluid according to claim 4, wherein at least said first sampling means opposes a pair of light transmitting portions formed of a light transmissive material at predetermined intervals (cell lengths) to circulate between the light transmitting portions. A transmission light measuring flow cell for measuring light intensity irradiated from one side of the light transmitting part by irradiating light from one side of the light transmitting part. The substrate processing apparatus which formed the excitation film. 7. The substrate treating apparatus of claim 6, wherein the coating is made of fluorine resin. 5. The light emitting means according to claim 4, wherein the first and second transmitted light intensity measuring means comprise a single light source used for both means, and an optical branch means for diverting the light generated from the light source to the first and second sampling means. And a single photodetector for receiving light transmitted separately from the first and second sampling means and outputting a signal according to each intensity, and separately transmitting the first and second sampling means. And an optical path switching means for alternately injecting one light into the photodetector, taking in a signal from the photodetector in synchronization with the switching timing of the optical path switching means, and the photodetector receiving the light transmitted through the second sample collecting means. A device for measuring the output signal of the photodetector as a reference transmission light intensity and the output signal of the photodetector as a reference transmission light intensity when the light detector receives light that has passed through the first sampling means. Processor. 9. The optical path switching means according to claim 8, wherein the optical path switching means comprises: a light selection shutter formed by forming a light transmitting portion and a light shielding portion in a predetermined ratio, the transmitted light of the second sampling means, and the transmitted light of the first sampling means. And driving means for driving the light selection shutter to alternately irradiate the photodetector. 9. The method of claim 8, wherein the first and second transmission light intensity measuring means repeats the measurement of the transmission light intensity of each of the reference transmission light intensity and the sample transmission light intensity and the measurement of the reference transmission light intensity, respectively. Ratio of transmitted light intensity to reference transmitted light intensity, ratio of i + 1th transmitted light intensity to i-th reference transmitted light intensity, ratio of i + 1th transmitted light intensity to reference transmitted light intensity, respectively A substrate processing apparatus for calculating a moving average of the ratio due to the transmitted light intensity and the reference transmitted light intensity adjacent to each other in time. The transmission control intensity of the processing liquid used for the processing of the substrate and the transmission light intensity of the solvent constituting the processing liquid are measured by common transmission light intensity measuring means, and the concentration control method of controlling the concentration of the processing liquid based on the measurement result. (A) storing the calibration curve data indicating the relationship between the solvent temperature and the transmitted light intensity by measuring the transmitted light intensity of the solvent alone by the transmitted light intensity measuring means while changing the temperature of the solvent constituting the treatment liquid; (b) measuring the transmitted light intensity of the reference treatment liquid previously adjusted to a predetermined concentration and temperature by the transmitted light intensity measuring means as the reference transmitted light intensity, and (c) the transmitted light intensity of the solvent as the reference transmitted light intensity as the transmitted light intensity. (D) Solvent based on the process measured by the strength measuring means and (d) the temperature of the reference processing liquid and stored calibration data. Calculating a predicted transmitted light intensity corresponding to the transmitted light intensity of the solvent to be measured by the transmitted light intensity measuring means when the temperature is equal to, and calculating a correction coefficient from the ratio between the reference transmitted light intensity and the predicted transmitted light intensity; (e) calculating the transmittance of the reference treatment liquid at the predetermined temperature as the reference transmittance from the reference transmittance intensity and the reference transmittance intensity and the correction coefficient, and then setting the reference reference value, and (f) processing the substrate. Measuring the transmission light intensity of the treatment liquid actually used by the transmission light intensity measurement means as the sample transmission light intensity, and (g) calculating the transmittance of the processing liquid as the sample transmission rate from the sample transmission light intensity and the reference transmission light intensity and correction coefficient. And (h) controlling the concentration of the treatment liquid to be actually used for processing the substrate according to the reference transmittance and the sample transmittance. And a feedback control process of repeating the control method so that the reference transmittance and the sample transmittance are repeated. 12. The method according to claim 11, wherein the reference transmittance intensity is measured by performing the process of (c) again before the procedure of (f), and after obtaining a correction coefficient from the ratio between this and the estimated transmittance intensity, Concentration control method to carry out the process. The method of claim 11, wherein the step (a) measures the transmitted light intensity at each temperature, and measures the light intensity associated with the light source related to the light intensity of the light source at each temperature, thereby measuring the light intensity at each temperature. The ratio between the transmitted light intensity and the light intensity related to the light source (transmitted light intensity ratio) is stored as calibration curve data, and in each of the steps (b), (c) and (f), Concentration control method that measures the light intensity related to the light source along with the measurement to find the ratio between the transmitted light intensity and the light intensity related to each light source and performs calculation based on their ratio in each process. A substrate processing apparatus for processing a substrate by a processing liquid adjusted to a predetermined concentration and temperature, comprising: a substrate storage means for storing a substrate to be processed and a processing liquid for processing a substrate stored in the substrate storage means; A processing liquid storage means, a chemical liquid supplying means for supplying a chemical liquid or a gas thereof, to the processing liquid storage means, a solvent supplying means for supplying a solvent constituting the processing liquid to the processing liquid storage means, and a processing liquid storage means A processing liquid supplying means for supplying the processing liquid stored in the means to a substrate housed in the substrate storage means, a sampling means for separately collecting the processing liquid and the solvent constituting the light having a light transmission portion having a predetermined optical path length, and The reference transmitted light intensity and the light irradiation means by measuring the intensity of the light transmitted through the sampling means obtained by collecting the reference treatment liquid adjusted to a predetermined concentration and temperature (reference transmitted light intensity). The ratio of the intensity of light generated from the light source to the intensity of light (related to the light source) is obtained as the reference transmission intensity ratio, and the reference intensity is determined by measuring the intensity of the light transmitted through the sampling means obtained by collecting only the solvent constituting the treatment liquid. And the ratio between the intensity of light generated by the light irradiation means and the reference transmittance intensity ratio, and the intensity of the light transmitted through the sample collection means obtained from the processing liquid actually used for processing the substrate was measured and measured. The transmission light intensity ratio measuring means for obtaining the ratio between the sample transmission light intensity and the light intensity generated by the light irradiation means as the sample transmission light intensity ratio, and sampling the transmission light intensity of only the solvent while varying the temperature of the solvent constituting the treatment liquid. A calibration curve data collection means for measuring calibration curve data indicating a relationship between the solvent temperature and the transmitted light intensity, and the reference treatment liquid. And the ratio between the predicted transmitted light intensity corresponding to the transmitted light intensity measured by the sampling means when the solvent is at the same temperature as the reference treatment liquid and the intensity of light generated by the light irradiation means based on the collected calibration curve data. Is calculated as a predicted transmission intensity ratio and a correction crab calculating means for calculating a correction coefficient from the ratio between the reference transmission intensity ratio and the predicted transmission intensity ratio, the reference transmission intensity ratio, the reference transmission intensity ratio and the correction coefficient at the predetermined temperature. A reference transmittance calculating means for calculating the transmittance of the reference treatment solution as a reference transmittance; a sample transmittance calculating means for calculating the transmittance of the treatment liquid as a sample transmittance from a sample transmittance intensity ratio, a reference transmittance intensity ratio, and a correction coefficient; The chemical liquid supply means and the solvent supply means are controlled according to the sample transmittance to actually process the substrate. A substrate processing apparatus having the density control means for controlling the concentration of the treatment liquid to be for. The substrate processing apparatus according to claim 14, wherein the concentration control means includes a feedback control means for controlling the chemical liquid supply stage and the solvent supply means in accordance with the difference between the reference transmittance and the sample transmittance. 15. The light transmitting portion according to claim 14, wherein the sample collecting means opposes a pair of light transmitting portions formed of a light transmissive material at predetermined intervals (cell length) and with respect to a fluid to be measured which flows between the light transmitting portions. A transmission cell for measuring light intensity by irradiating light from one side of the light transmitting part and measuring the light intensity emitted from the other side of the light transmitting part, and having a corrosion resistance against the fluid to be measured on the surface of the pair of light transmitting parts. Substrate treatment apparatus for forming a. 17. The substrate treating apparatus of claim 16, wherein the coating is made of fluorine resin. 15. The method according to claim 14, wherein the non-measurement means for measuring the transmitted light intensity includes a single light source, an optical filter having a predetermined photosensitivity, and an optical branching means for branching the light generated from the light source to the sample collecting means and the optical filter. A single photodetector for receiving the light transmitted separately from the means and the optical filter and outputting a signal according to each intensity, and an optical path switching for alternately injecting the light transmitted separately from the sample collection means and the optical filter to the photodetector. Means for receiving a signal from the photodetector in synchronization with the switching timing of the optical path switching means, and outputting the output signal of the photodetector when the photodetector receives the light passing through the sampling means; And the light transmission power of the photodetector when the light detector receives the light transmitted through the optical filter. A substrate processing apparatus for measuring each of an intensity of the light (light source gwangryeon light intensity) generated in the light irradiation means. 19. The optical path switching means according to claim 18, wherein the optical path switching means alternately irradiates the optical detector with an optical selection shutter which forms a light transmission portion and a light shielding portion at a predetermined ratio, and the transmitted light of the optical filter and the transmitted light of the sample collecting means. A substrate processing apparatus constituted by driving means for driving the light selection shutter. 19. The method according to claim 18, wherein the transmission light intensity ratio measuring means measures the transmission light intensity of each of the reference transmission light intensity, the reference transmission light intensity, and the sample transmission light intensity, and the measurement of the light source related light intensity. Arbitrary natural number) ratio of the transmitted light intensity to the light source related light intensity, the ratio of the i + 1th transmitted light intensity to the i-th light source related light intensity, the i + 1th transmitted light intensity to the sugar source related light, respectively A substrate processing apparatus comprising a reference transmission intensity ratio, a reference transmission intensity ratio, and a sample transmission intensity ratio by calculating a moving average of ratios of transmitted light intensity and light source related light intensity which are adjacent to each other in time such as the ratio with intensity.