TWI435384B - Etching fluid management device - Google Patents

Description

Etching fluid management device

The present invention is used in an aluminum film (for example, a film of aluminum or aluminum alloy, a first film of molybdenum or molybdenum alloy, and a second film of aluminum or aluminum alloy; or hereinafter referred to as an aluminum film) in a semiconductor manufacturing process or a liquid crystal substrate manufacturing process. More specifically, the apparatus for managing the etching liquid for etching includes a continuous automatic replenishing mechanism and an acid concentration adjusting mechanism for circulating the etching liquid.

In the aluminum film etching process of the liquid crystal substrate manufacturing process, a mixed aqueous solution of nitric acid and phosphoric acid as an etching solution, a mixed aqueous solution of nitric acid, phosphoric acid and acetic acid, a mixed aqueous solution of nitric acid, phosphoric acid, and malonic acid, etc. The mixed acid aqueous solution of the main component is used in the form of a sprayer or a soaking method. A mixed aqueous solution of nitric acid, phosphoric acid and acetic acid is mostly used. For example, an aqueous solution having a phosphoric acid concentration of 70.0%, an acetic acid concentration of 10.0%, a nitric acid concentration of 4.0%, and a remaining water concentration of 16.0% can be mentioned.

In the conventional method, after the etching liquid treatment tank is filled with a predetermined amount of the etching liquid, the number of the substrate processing sheets is used as an index, and the etching liquid is reduced to the predetermined degradation concentration range. At the same time, the new liquid prepared in advance is completely replaced, that is, the form of the batch operation is taken. The liquid replacement period is not limited depending on the tank capacity, the type of the substrate, the number of sheets, and the like, but is preferably performed at a frequency of four hours.

As a mixed acid aqueous solution used as an etching solution for an aluminum thin film, nitric acid or acetic acid is used to evaporate together with the exhaust gas from the etching bath, and thus the nitric acid concentration or the acetic acid concentration is lowered to cause a concentration fluctuation. Also, with the etching reaction, nitric acid is consumed to cause a decrease in the concentration of nitric acid. Further, although phosphoric acid is consumed as an aluminum salt, it is concentrated by evaporation of nitric acid, acetic acid, and water, and the phosphoric acid concentration is increased (for example, see Patent Document 1).

[Patent Document 1] JP-A-2004-319568

Therefore, the successive etching performance is lowered, but in the past, it has hardly been performed to accurately measure the respective acid concentrations, and it is difficult to control the concentration to a certain concentration.

Although some devices have been intermittently measured for concentration management by non-aqueous and titration methods, since the device is complicated, it is necessary to use a titration reagent, and it is intermittently measured, so there are many cases such as poor controllability. The problem.

Further, there is a concentration management device for measuring the concentration of nitric acid by ultraviolet absorption spectrophotometry. However, the NOx component generated by the etching reaction has a problem that the absorbance of the wavelength range of the nitric acid concentration is hindered.

Further, once molybdenum is dissolved by etching, there is a problem that the wavelength in the wavelength range in which the nitric acid concentration is measured has an absorbance.

Further, there is a concentration management device which is measured by a combination of near-infrared absorption spectrophotometry and multivariate analysis, but the measurement accuracy of the most important nitric acid concentration is insufficient.

Therefore, the acid concentration of the etching liquid accompanying the etching of the substrate is constantly changed, and the etching speed is changed, so that the precision of the high-precision size of the etched aluminum film is difficult to control, and the tilt angle of the aluminum film is controlled. It is also difficult to cause the quality of the product to be unstable, resulting in a decrease in the yield.

Further, since the operation at the time of liquid replacement is stopped (Downtime), the operating rate is greatly reduced, and the labor cost associated with the replacement of the etching liquid is required.

The present invention has been made in view of the above-described points, and an object of the present invention is to solve the above-mentioned problems of the prior art while utilizing the advantages of a conventional linear transport method which is easy to use for mass production of a liquid crystal substrate manufacturing process. Pointer.

That is, the object of the present invention is to automatically control the etching liquid to a predetermined nitric acid concentration, acetic acid concentration, and phosphoric acid concentration, and to appropriately manage the liquid supply in the etching liquid treatment tank, thereby making it possible to appropriately manage the liquid solution. The etching performance is always constant, and the amount of the raw liquid used can be reduced, and the operation stop time can be drastically shortened, and the comprehensive manufacturing cost can be reduced.

In order to achieve the above object, the invention described in claim 1 is an etching liquid management device for use in an etching liquid management device for etching an etching solution, wherein the etching processing device includes an etching liquid processing tank for storing an etching solution containing nitric acid, An etching liquid circulation mechanism for circulating an etching liquid stored in the etching liquid processing tank, and an etching processing mechanism for transporting a substrate including an aluminum film etched by the etching liquid circulated by the etching liquid circulation mechanism, wherein The method includes: an etching liquid sampling means for sampling the etching liquid; and a dilution means for diluting the etching liquid sampled by the etching liquid sampling means with pure water; and a conductivity meter for measuring the dilution means by the above dilution means a conductivity value of the diluted etching solution to obtain a conductivity value related to a nitric acid concentration of the etching solution; and a replenishing liquid supply means for etching the conductivity based on a conductivity value obtained by the conductivity meter The liquid treatment tank supplies the replenishing liquid.

According to the invention of claim 1, the replenishing liquid supply means for supplying the replenishing liquid to the etching liquid processing tank based on the conductivity value (related to the nitric acid concentration) obtained by the conductivity meter is provided, for example, even if etching The conductivity of the liquid (related to the concentration of nitric acid) is lower than the target value (that is, the concentration of nitric acid in the etching solution is lowered), the etching performance is lowered, and the replenishing liquid can be supplied to the etching solution processing tank, so that the conductivity of the etching liquid can be correlated (related to The nitric acid concentration can be managed in such a manner that a predetermined target value can be formed, that is, the nitric acid concentration of the etching solution can be formed in a certain manner.

As a result, the etching performance can be kept constant, the amount of the raw liquid used can be reduced, and the work stop time can be greatly shortened, so that the comprehensive manufacturing cost can be reduced.

The invention described in claim 2 is an etching liquid management device for use in an etching liquid management device for an etching treatment device, comprising: an etching liquid processing tank for storing an etching liquid; and storing the etching liquid in the etching liquid An etching liquid circulation mechanism for circulating an etching solution in a bath, and an etching processing mechanism for transporting a substrate including an aluminum film etched by an etching liquid circulated by the etching liquid circulation mechanism, characterized in that: an etching liquid sampling means is provided The etchant is sampled; the absorbance photometer is configured to measure the absorbance of the etchant sampled by the etchant sampling means, thereby obtaining an absorbance value related to the water concentration of the etchant; and a replenishing liquid supply means. This is to supply a replenishing liquid to the etching liquid treatment tank based on the absorbance value obtained by the above-described absorptiometer.

According to the invention of the second aspect of the invention, the replenishing liquid supply means for supplying the replenishing liquid to the etching liquid processing tank is provided, for example, even if the replenishing liquid is supplied to the etching liquid processing tank. If the water concentration is lower than the target value (that is, the water concentration of the etching solution is lowered), the etching performance is lowered, and the replenishing liquid can be supplied to the etching liquid processing tank, so that the absorbance value (related to the water concentration) of the etching liquid can be formed into a predetermined The manner of the target value, that is, the concentration of the etchant liquid can be managed in a certain manner.

As a result, the etching performance can be kept constant, the amount of the raw liquid used can be reduced, and the work stop time can be greatly shortened, so that the comprehensive manufacturing cost can be reduced.

The invention described in claim 3 is an etching liquid management device for use in an etching liquid management device for an etching treatment device, comprising: an etching liquid processing tank for storing an etching solution containing phosphoric acid; An etching liquid circulation mechanism for etching the etching liquid in the etching liquid processing tank, and an etching processing mechanism for transporting the substrate including the aluminum film etched by the etching liquid circulated by the etching liquid circulation mechanism, characterized in that the etching liquid is provided a method for sampling an etching solution; and an absorptiometer for measuring an absorbance of an etching solution sampled by the etching liquid sampling means, thereby obtaining an absorbance value of a phosphoric acid concentration of the etching solution; and a replenishing liquid The supply means supplies the replenishing liquid to the etching liquid processing tank based on the absorbance value obtained by the absorptiometer.

According to the invention of claim 3, the replenishing liquid supply means for supplying the replenishing liquid to the etching liquid processing tank based on the absorbance value (related to the phosphoric acid concentration) obtained by the spectrophotometer is provided, for example, even the etching liquid The absorbance value (corresponding to the phosphoric acid concentration) is lower than the target value (that is, the phosphoric acid concentration of the etching solution is lowered), the etching performance is lowered, and the replenishing liquid can be supplied to the etching solution processing tank, so that the absorbance value of the etching liquid can be correlated (related to phosphoric acid) The concentration can be managed in such a manner that a predetermined target value can be formed, that is, the phosphoric acid concentration of the etching solution can be formed in a certain manner.

As a result, the etching performance can be kept constant, the amount of the raw liquid used can be reduced, and the work stop time can be greatly shortened, so that the comprehensive manufacturing cost can be reduced.

The invention described in claim 4 is an etching liquid management device for use in an etching liquid management device for an etching treatment device, comprising: an etching liquid processing tank for storing an etching solution containing phosphoric acid; An etching liquid circulation mechanism for etching the etching liquid in the etching liquid processing tank, and an etching processing mechanism for transporting the substrate including the aluminum film etched by the etching liquid circulated by the etching liquid circulation mechanism, characterized in that the etching liquid is provided a method for sampling an etching solution; a density meter for measuring a density of an etching solution sampled by the etching liquid sampling means, thereby obtaining a density value of a phosphoric acid concentration associated with the etching liquid; and a supply of a replenishing liquid The method is to supply a replenishing liquid to the etching liquid processing tank based on a density value obtained by the density meter.

According to the invention of claim 4, the replenishing liquid supply means for supplying the replenishing liquid to the etching liquid processing tank based on the density value (related to the phosphoric acid concentration) obtained by the densitometer is provided, for example, even if the etching liquid is used. The density value (corresponding to the phosphoric acid concentration) is lower than the target value (that is, the phosphoric acid concentration of the etching solution is lowered), the etching performance is lowered, and the replenishing liquid can be supplied to the etching solution processing tank, so that the density value of the etching liquid can be correlated (related to the phosphoric acid concentration) The manner in which the predetermined target value can be formed, that is, the phosphoric acid concentration of the etching solution can be managed in a certain manner.

As a result, the etching performance can be kept constant, the amount of the raw liquid used can be reduced, and the work stop time can be greatly shortened, so that the comprehensive manufacturing cost can be reduced.

The invention described in claim 5 is an etching liquid management device for use in an etching liquid management device for an etching treatment device, comprising: an etching liquid processing tank for storing an etching liquid containing nitric acid and phosphoric acid, and storing An etching liquid circulation mechanism for circulating an etching solution in the etching liquid processing tank, and an etching processing mechanism for transporting a substrate including an aluminum film etched by the etching liquid circulated by the etching liquid circulation mechanism, characterized in that: etching is provided a liquid sampling means for sampling an etching solution; a dilution means for diluting an etching solution sampled by the etching liquid sampling means with pure water; and a conductivity meter for measuring the dilution by the dilution means a conductivity value of the etching solution to obtain a conductivity value related to a nitric acid concentration of the etching solution; and an absorptiometer for measuring an absorbance of the etching solution sampled by the etching liquid sampling means, thereby obtaining the correlation An absorbance value of the water concentration of the etching solution; and an absorptiometer that measures the etching sampled by the etching liquid sampling means The absorbance of the liquid is used to obtain the absorbance value of the phosphoric acid concentration of the etching solution, or the density meter is used to measure the density of the etching solution sampled by the etching liquid sampling means, thereby obtaining the etching liquid. Density value of phosphoric acid concentration; component concentration calculation method, which uses a multi-component algorithm (multiple regression analysis. multivariate analysis method), from the concentration of nitric acid obtained by the above conductivity meter The conductivity value, the absorbance value obtained by the above-mentioned absorption photometer, and the absorbance value or density value related to the phosphoric acid concentration obtained by the above-mentioned absorptiometer or the above densitometer The component concentration of the etching solution; and the replenishing liquid supply means for supplying the replenishing liquid to the etching solution processing tank based on the component concentration calculated by the component concentration calculation means.

According to the invention described in the claim 5, since the component concentration calculation means for calculating the component concentration of the etching liquid by the multi-component algorithm (multiple regression analysis method, multivariate analysis method) is provided, it is possible to calculate each component more accurately. The concentration of the components can be more correctly managed so that the concentration of each component of the etching solution can form a predetermined target value.

As a result, the etching performance can be kept constant, the amount of the raw liquid used can be reduced, and the work stop time can be greatly shortened, so that the comprehensive manufacturing cost can be reduced.

According to the invention of claim 1 to 5, the etchant is an aqueous solution containing phosphoric acid or nitric acid.

This is an illustration of an etchant.

According to the invention of claim 6, the etchant is an aqueous solution containing at least one of organic acid, hydrochloric acid, sulfuric acid, and perchloric acid.

This is also an illustration of the etching solution.

According to the invention of claim 7, in the invention of claim 7, the organic acid is acetic acid or malonic acid.

The invention described in claim 9 is an etching liquid concentration measuring device, which is an etching liquid concentration measuring device used in an etching processing device, the etching processing device comprising: an etching liquid processing tank for storing an etching liquid containing nitric acid and phosphoric acid; An etching liquid circulation mechanism that circulates an etching liquid stored in the etching liquid processing tank, and an etching processing mechanism that transports an aluminum film that is etched using an etching liquid circulated by the etching liquid circulation mechanism, is characterized in that An etching liquid sampling means for sampling an etching liquid; and a dilution means for diluting an etching liquid sampled by the etching liquid sampling means with pure water; and a conductivity meter for measuring by the above dilution means The conductivity of the diluted etching solution is used to obtain a conductivity value related to the nitric acid concentration of the etching solution; and the absorptiometer is configured to measure the absorbance of the etching solution sampled by the etching liquid sampling means, thereby obtaining correlation An absorbance value of the water concentration of the etching solution; and an absorptiometer, which is measured by the etching liquid sampling means The absorbance of the etching solution is used to obtain the absorbance value of the phosphoric acid concentration of the etching solution, or the density meter is used to measure the density of the etching solution sampled by the etching liquid sampling means, thereby obtaining The density value of the phosphoric acid concentration of the etching solution; and the component concentration calculation method, which uses a multi-component algorithm (multivariate regression analysis method, multivariate analysis method), and the correlation with the nitric acid concentration obtained by the above conductivity meter The conductivity value, the absorbance value obtained by the above-mentioned absorption photometer, and the absorbance value or density value related to the phosphoric acid concentration obtained by the above-mentioned absorptiometer or the above-mentioned densitometer are used to calculate the above etching. The concentration of the liquid.

According to the invention described in the claim 9, the component concentration calculation means for calculating the component concentration of the etching liquid by the multi-component algorithm (multivariate regression analysis method, multivariate analysis method) is provided, so that a more accurate calculation can be obtained. An etchant concentration measuring device for each component concentration.

The invention according to claim 10, characterized in that the etching liquid containing nitric acid is diluted with pure water, and the conductivity of the diluted etching liquid is measured using a conductivity meter, thereby obtaining the etching liquid. Conductivity value of nitric acid concentration.

According to the invention described in the claims 10 and 15, the measurement of the nitric acid concentration of the etching liquid which has been difficult to measure in the past can be performed by diluting only the etching liquid containing nitric acid in pure water, and measuring the etching after the dilution using a conductivity meter. The conductivity of the liquid.

The invention according to claims 11 and 16, characterized in that the absorbance of the etching liquid is measured by an absorptiometer to obtain an absorbance value relating to the water concentration of the etching liquid.

According to the invention described in the claims 11 and 16, the measurement of the water concentration of the etching liquid which has been difficult to measure in the past can be carried out by measuring only the absorbance of the etching liquid using an absorbance meter.

The invention according to claim 12, wherein the absorbance of the phosphoric acid-containing etching solution is measured by an absorptiometer to obtain an absorbance value of the phosphoric acid concentration of the etching solution.

According to the invention described in the claims 12 and 17, the measurement of the phosphoric acid concentration of the etching liquid which has been difficult to measure in the past can be carried out by measuring only the absorbance of the etching liquid using an absorbance meter.

The invention according to claims 13 and 18 is characterized in that the density of the phosphoric acid-containing etching solution is measured using a densitometer to obtain a density value of the phosphoric acid concentration in relation to the etching solution.

According to the invention described in the claims 13 and 18, the measurement of the phosphoric acid concentration of the etching liquid which has been difficult to measure in the past can be performed by measuring only the density of the etching liquid using a densitometer.

The invention described in claims 14 and 19 is characterized in that a multi-component algorithm (multivariate regression analysis method, multivariate analysis method) is used to dilute an etching solution containing nitric acid and phosphoric acid in pure water, using a conductivity meter. a conductivity value obtained by measuring the conductivity of the diluted etching liquid, an absorbance value obtained by measuring the absorbance of the etching liquid using an absorption photometer, and an absorbance value obtained by using an absorption photometer to measure the etching liquid The component concentration of the etching liquid is calculated by the absorbance value obtained by the absorbance and the density value of the phosphoric acid concentration obtained by measuring the density of the etching liquid using a densitometer.

According to the invention described in the claims 14 and 19, the multi-component algorithm (multiple regression analysis method, multivariate analysis method) can be used to more accurately calculate the concentration of each component (calculation of the concentration of the etching solution). Liquid concentration measuring device.

According to the present invention, the etching liquid can be automatically controlled to a predetermined nitric acid concentration, acetic acid concentration, and phosphoric acid concentration, and the liquid supply to the etching liquid treatment tank can be appropriately managed, and the etching performance can be constantly changed, and the use can be reduced. The amount of raw liquid can greatly shorten the operation stop time and reduce the comprehensive manufacturing cost.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. However, the shape of the constituent device described in the above-described embodiments, the relative arrangement thereof, and the like are not limited to the scope of the present invention unless otherwise specified, and these are merely illustrative examples.

[First Embodiment]

Fig. 1 is a system diagram for explaining an etching liquid management device according to a first embodiment of the present invention.

The etching management apparatus of the present embodiment is mainly applied to the management of the nitric acid concentration of the etching liquid in the etching process, and includes the etching liquid processing unit A, the etching liquid stirring unit B, the replenishing liquid supply unit C, and the conductivity measuring unit D. The etching liquid level level controller 29, the nitric acid concentration control unit 30, and the like.

[etching solution processing unit A]

The etching liquid processing unit A is a member for etching the surface of the substrate by ejecting an etching liquid onto the surface of the substrate to be conveyed.

As shown in FIG. 1, the etching liquid processing unit A includes an etching liquid processing tank 1 in which an etching liquid is stored, an overflow tank 2 for receiving an etching liquid overflowing from the etching liquid processing tank 1, and an etching chamber cover 4. A roller conveyor 5 for transporting the substrate 6 above the etching solution processing tank 1, an etchant spray 7, and the like.

The etching solution processing tank 1 and the etching liquid atomizer 7 are connected by a circulation line 10 which is a filter 9 in which a liquid supply pump 8 and fine particles for removing the etching liquid are provided in the middle.

When the liquid feeding pump 8 is actuated, the etching liquid stored in the etching liquid processing tank 1 is supplied to the etching liquid atomizer 7 via the circulation line 10, and is ejected from the etching liquid atomizer 7. Thereby, the surface of the substrate 6 conveyed by the roller conveyor 5 is etched. Further, the surface of the substrate 6 is covered with an aluminum film (for example, a film of aluminum or aluminum alloy, a first film of molybdenum or molybdenum alloy, and a second film of aluminum or aluminum alloy; hereinafter referred to as an aluminum film).

The etching liquid after the etching is dropped to the etching liquid processing tank 1 and stored again, and is supplied to the etching liquid atomizer 7 via the circulation line 10 in the same manner as above, and is ejected from the etching liquid atomizer 7.

[etching solution stirring section B]

The etching liquid stirring portion B is mainly used to agitate the etching liquid stored in the etching liquid processing tank 1.

The bottom portion and the side portion of the etching solution processing tank 1 are connected by a circulation line 12 which is provided with a circulation pump 11 and a fine particle removing filter 13 in the middle.

When the circulation pump 11 is actuated, the etching liquid stored in the etching solution processing tank 1 is circulated through the circulation line 12. Thereby, the cleaning and stirring of the etching liquid stored in the etching liquid processing tank 1 are performed.

When the replenishing liquid flows into the circulation line 12 via the joining line 28, the inflowing replenishing liquid is supplied into the etching liquid processing tank 1 while being mixed with the circulating etching liquid in the circulation line 12.

[Replenishment liquid supply unit C]

The replenishing liquid supply unit C is for supplying the replenishing liquid into the etching liquid processing tank 1. The replenishing solution includes an etching stock solution, a nitric acid stock solution, an etching new liquid, and pure water. It is not always necessary, and the optimum replenishing liquid and supply device are selected in accordance with the composition of the etching liquid, the degree of concentration change, equipment conditions, operating conditions, and conditions for obtaining the replenishing liquid. The etching stock solution includes a monoacid stock solution such as acetic acid or phosphoric acid, a mixed acid stock solution containing nitric acid and acetic acid, and the like.

The replenishing liquid supply unit C is provided with an etching raw material supply tank 20 for storing each replenishing liquid, a nitric acid raw material supply tank 21, an etching new liquid supply tank 22, and a piping for supplying pure water.

Each of the tanks 20 to 22 and the existing piping for supplying pure water are connected to the branch line, and the branch line is juxtaposed from the joining line 28 connected to the circulation line 12. Flow regulating valves 24 to 27 that are opened and closed by the liquid level level controller 29 (or the conductivity controller 30) are provided in the middle of each of the branch lines. Further, the supply pipe 23 in the tank 22 is connected 20 to an N ₂ gas, N ₂ gas supplied by the pipe 23 from the tank 20 to the respective pressurized to ~ 22 0.1 ~ 0.2MPa. Therefore, once at least one of the flow control valves 24 to 26 can be opened by the liquid level level controller 29 (or the conductivity controller 30), the replenishing liquid corresponding to the controlled flow regulating valve The pressure is transferred to the etching solution processing tank 1 via the branch line, the joining line 28, and the circulation line 12.

For example, once the flow rate regulating valve 24 is controlled by the liquid level level controller 29 (or the conductivity controller 30), the etching stock solution stored in the etching stock solution supply tank 20 passes through the branch line and the junction tube. The path 28 and the circulation line 12 are pumped into the etching solution processing tank 1. At the same time, once the flow rate regulating valve 27 is controlled by the liquid level level controller 29 (or the conductivity controller 30), the pure water will pass from the existing piping through the branch line, the joining line 28, and the circulation pipe. The path 12 is supplied into the etching solution processing tank 1.

Further, each of the replenishing liquid flows into the circulation line 12 via the branch line and the junction line 28, and is supplied into the etching liquid processing tank 1 while being mixed with the circulating etching liquid in the circulation line 12. Further, the branch lines may be directly connected to the circulation line 12 or the etching liquid processing tank 1 without passing through the joining line 28.

The supply amount of each replenishing liquid to the etching liquid processing tank 1 can be adjusted, for example, by the liquid level level controller 29 (or the conductivity controller 30) controlling the time at which the respective flow rate adjusting valves 24 to 27 are turned on.

Further, a liquid discharge pump 19 for discharging the etching liquid stored in the etching liquid processing tank 1 is provided.

[Electrical conductivity measuring unit D]

The inventors have found out that there is a correlation between the nitric acid concentration of the etching liquid stored in the etching liquid processing tank 1 and the conductivity of the etching liquid (hereinafter referred to as a diluent) diluted with pure water to a predetermined ratio.

2 is a graph showing the conductivity of the diluent on the vertical axis and the nitric acid concentration on the horizontal axis, and plots the conductivity of the diluted solution after actual measurement and the concentration of nitric acid corresponding to the conductivity of the diluent. As is clear from Fig. 2, the conductivity of the diluent and the concentration of nitric acid corresponding to the conductivity of the diluent are plotted along a straight line rising to the right. That is, it can be understood that there is a linear relationship between the conductivity of the diluent and the nitric acid concentration of the diluent, and the conductivity of the diluent is detected based on the relationship, and the conductivity value related to the nitric acid concentration can be obtained.

The conductivity measuring unit D measures the conductivity of the etching liquid that is circulated in the etching liquid processing unit A based on the findings of the inventors, and obtains the conductivity value related to the nitric acid concentration.

The conductivity measuring unit D includes a sampling line 34 that is connected to the circulation line 10 and is provided with the sampling pump 38 in the middle, a pure water supply line 35 that is connected to a pure water source (not shown), and is provided with a pure water pump 39 in the middle, and is connected. The sampling line 34 and the pure water supply line 35 flow from the sampling line 34 and the pure water supply line 35 into the joining line 36 of the etching liquid and the pure water, and the connecting joining line 36 for measuring the dilution of the inflow combining line 36. Conductivity meter 15 which is a conductivity of a predetermined ratio of etching liquid.

When the sampling pump 38 and the pure water pump 39 are actuated, the etching liquid sampled from the circulation line 10 via the sampling line 34 and the pure water supplied from the pure water supply line 35 are the inflow combined line 36, in the confluent tube The inside of the path 36 is diluted to a predetermined ratio (mixed and stirred), and then supplied to the conductivity meter 15.

The dilution ratio is adjusted, for example, by adjusting the liquid supply flow rate of the sampling pump 38 and the pure water pump 39.

The conductivity meter 15 continuously measures the conductivity of the diluent. Thereby, the conductivity value related to the nitric acid concentration can be obtained. In addition, the final dilution of the assay is drained from line 37.

In the conductivity meter 15, although the conductivity of the diluted etching liquid is measured, the dilution is performed at a predetermined ratio (for example, 10 times), and the nitric acid concentration of the etching liquid before dilution can be measured. In addition, the conductivity meter 15 has compensating functions for minimizing measurement errors.

[etching level controller 29]

The etching liquid level level controller 29 is for managing the etching liquid amount of the etching liquid in the etching liquid processing tank 1 within a certain range.

The liquid level level controller 3 is connected to the liquid level level controller 3 and the flow rate adjusting valves 24 to 27. The liquid level gauge 3 is a liquid level level for detecting the etching liquid provided in the etching liquid processing tank 1, and is detected in the etching process by being attached to the substrate 6 and being taken out to the outside. The level of the liquid level is lowered, or the level of the liquid when the liquid which deteriorates the etching performance is forcibly discharged is lowered.

The liquid level level controller 29 opens and closes at least one of the flow rate adjusting valves 24 to 27 so that a liquid level level input from the liquid level level 3 can form a predetermined target value. Thereby, the replenishing liquid corresponding to the controlled flow rate adjusting valve is supplied into the etching liquid processing tank 1. Usually, the level of the liquid level of the etching solution processing tank 1 is controlled at a position near the liquid level level 3 which does not reach the overflow. Further, the target value is set in advance in the controller 29 or the like.

[Conductivity Controller 30]

The conductivity controller 30 is for managing the nitric acid concentration of the etching liquid in the etching solution processing tank 1 within a certain range.

The conductivity meter 30 and the flow rate adjusting valves 24 to 27 are connected to the conductivity controller 30. The conductivity controller 30 opens and closes at least one of the control flow rate adjusting valves 24 to 27 such that the conductivity input from the conductivity meter 15 can form a predetermined target value. Thereby, the replenishing liquid corresponding to the controlled flow rate adjusting valve is supplied into the etching liquid processing tank 1, and the conductivity (that is, the nitric acid concentration) is adjusted. In addition, the target value of the nitric acid concentration (the nitric acid concentration of the etching liquid necessary for the quality management of the product substrate) is predetermined in advance by the controller 30 or the like based on the work performance or calculation.

[Example of operation]

Next, the operation of the etching processing apparatus having the above configuration will be described. Hereinafter, an example in which the etching liquid is a solution in which mixed nitric acid, phosphoric acid, acetic acid, and pure water (for example, a certain liquid temperature maintained at about 40 ° C) is used will be described.

The etching liquid level level controller 29 is configured to input from the liquid level level 3 when the liquid level level input from the liquid level level 3 is less than a predetermined target value (for example, when the etching liquid processing tank 1 is empty). The level of the liquid level can be controlled to form at least one of the flow regulating valves 24 to 27 in such a manner as to form a predetermined target value.

Thereby, the replenishing liquid corresponding to the controlled flow rate adjusting valve flows into the circulation line 12 via the branch line and the junction line 28, and is mixed with the circulating etching liquid in the circulation line 12, and supplied thereto. The etching solution is treated in the tank 1.

For example, the etching level controller 29 is controlled to open the flow regulating valve when the level of the liquid level input from the level gauge 3 does not reach a predetermined target value (for example, when the etching solution processing tank 1 is empty). 26. Thereby, the pre-mixed etching new liquid corresponding to the controlled flow regulating valve 26 flows into the circulation line 12 via the branch line and the junction line 28, and the circulating etching liquid in the circulation line 12 The mixture is supplied to the etching solution processing tank 1 while being mixed. Alternatively, it is controlled so that the respective flow rate adjusting valves 24, 25, and 27 can be opened, and the etching stock solution, the nitric acid raw liquid, and the pure water can be supplied into the etching liquid processing tank 1 so as to form a concentration substantially equal to that of the etching new liquid.

Then, the etching level controller 29 is controlled to close the flow regulating valve previously controlled to be turned on when the level of the liquid level input from the level gauge 3 reaches a predetermined target value.

The amount of the etching liquid of the etching liquid in the etching liquid processing tank 1 can be managed within a certain range by the control of the etching liquid level level controller 29 described above. The control of the etching liquid level level controller 29 is also continued after the etching of the etching liquid processing unit A is started. Therefore, even if the etching liquid is removed to the outside due to adhesion to the substrate 6 during the etching of the etching liquid processing portion A, the etching liquid in the etching liquid processing tank 1 can be reduced, and the etching liquid amount of the etching liquid in the etching liquid processing tank 1 can be obtained. Managed in a certain range. As a result, the fresh replenishing liquid can be replenished, and the etching performance is restored when the dissolved aluminum concentration is diluted. Further, by the discharge pump 19, the etching deterioration liquid is discharged through the piping for discharge. Further, the etching deterioration liquid may be directly extracted to the outside without passing through the piping for discharging.

Next, etching of the etching liquid processing unit A is started. In other words, when the liquid feeding pump 8 is actuated, the etching liquid stored in the etching liquid processing tank 1 is supplied to the etching liquid atomizer 7 via the circulation line 10, and is ejected from the etching liquid atomizer 7. Thereby, the surface of the substrate 6 conveyed by the roller conveyor 5 is etched.

The etching liquid after the etching is dropped to the etching liquid processing tank 1 and stored again, and is supplied to the etching liquid atomizer 7 via the circulation line 10 in the same manner as above, and is ejected from the etching liquid atomizer 7.

During the etching of the etching liquid processing unit A as described above, mainly as the number of processed sheets of the substrate 6 increases, the nitric acid evaporates together with the exhaust gas, so that the nitric acid concentration of the etching liquid is reduced, so the etching performance of the etching liquid is gradually lowered. Reduced ground. Further, since the nitric acid is consumed by the etching reaction, the concentration of nitric acid is reduced, so the etching performance of the etching solution is gradually lowered.

Then, in order to prevent a decrease in etching performance due to a decrease in the nitric acid concentration of the etching liquid, the following control is performed.

That is, when the sampling pump 38 and the pure water pump 39 are actuated, the etching liquid sampled from the circulation line 10 via the sampling line 34 and the pure water supplied from the pure water supply line 35 flow into the joining line 36. After being diluted to a predetermined ratio (mixed and stirred) in the joining line 36, it is supplied to the conductivity meter 15.

The dilution ratio is adjusted, for example, by adjusting the liquid supply flow rate of the sampling pump 38 and the pure water pump 39.

Alternatively, the sampling pump 38 may be connected to the etching solution processing tank 1 for sampling.

The conductivity meter 15 continuously measures the conductivity of the diluent. Thereby, the conductivity value related to the nitric acid concentration can be obtained. In addition, the final dilution of the assay is drained from line 37.

The conductivity controller 30 is controlled to at least one of the openable flow regulating valves 24, 25, 27 in such a manner that the conductivity input from the conductivity meter 15 can form a predetermined target value (for example, 4.0 ± 1.0%). Flow regulating valve.

For example, the conductivity controller 30 controls the openable flow regulating valve 25 in such a manner that the conductivity input from the conductivity meter 15 can form a predetermined target value when the conductivity of the etching liquid is lower than the target value. . Further, once the concentration of nitric acid is lowered, the concentration of acetic acid is also lowered. Therefore, if acetic acid as an etching stock solution is previously stored in the tank 20, the conductivity controller 30 can be controlled to a predetermined range of acetic acid by opening the flow regulating valve 24. concentration.

Thereby, the replenishing liquid corresponding to the controlled flow rate adjusting valve flows into the circulation line 12 via the branch line and the junction line 28, and is mixed with the circulating etching liquid in the circulation line 12, and supplied thereto. The etching solution is treated in the tank 1.

Then, the conductivity controller 30 is controlled to turn off the flow regulating valve previously controlled to be turned on when the conductivity input from the conductivity meter 15 reaches a predetermined target value.

The nitric acid concentration of the etching liquid in the etching solution processing tank 1 can be managed within a certain range by the control of the above-described conductivity controller 30. For example, in the etching of the etching liquid processing unit A, even if the concentration of nitric acid is lowered, the concentration of acetic acid is lowered, the concentration of phosphoric acid is increased, and the etching liquid is removed to the outside due to adhesion to the substrate 6, the etching liquid in the etching liquid processing tank 1 is reduced. The concentration of aluminum ions is concentrated, and the concentration of nitric acid in the etching liquid in the etching solution processing tank 1 can be managed within a certain range.

Further, in the present embodiment, normally, the level of the liquid level of the etching liquid processing tank 1 is operated at a position near the level of the liquid level which does not reach the overflow.

[Second embodiment]

Fig. 3 is a system diagram for explaining an etching liquid management device according to a second embodiment of the present invention.

In the etching liquid management apparatus of the first embodiment, the management of the concentration of the nitric acid in the etching liquid is important, and when the management of the water concentration is important, the measurement of the absorbance is added to the etching liquid management apparatus according to the first embodiment. Part E, and absorbance controller 31. Other configurations are the same as those of the first embodiment, and thus the description thereof will be omitted.

[Absorbance measuring unit E]

As a result of examining the relationship between the water concentration of the etching liquid and the absorbance, the inventors have found that the measurement wavelength of the absorbance is appropriate in the range of 1920 nm to 1960 nm in the near-infrared region, and particularly in the vicinity of 1931 nm.

4 is a graph showing the absorbance (the measurement wavelength λ=1931 nm) and the water concentration corresponding to the absorbance after the actual measurement, in which the vertical axis represents the absorbance and the horizontal axis represents the water concentration. As is clear from Fig. 4, the absorbance (measurement wavelength λ = 1931 nm) and the water concentration corresponding to the absorbance are plotted along a straight line rising to the right. That is, it can be understood that there is a linear relationship between the absorbance (measurement wavelength λ=1931 nm) and the water concentration, and the absorbance is detected based on the relationship, and the absorbance value related to the water concentration can be obtained.

The absorbance measuring unit E measures the absorbance of the etching liquid that is circulated in the etching liquid processing unit A based on the findings of the inventors, and thereby obtains the absorbance value related to the water concentration.

The absorbance measuring unit E is provided with an absorptiometer 16 for measuring the absorbance (for example, the measurement wavelength λ=1931 nm) of the etching liquid flowing in through the line 14 branched from the circulation line 10.

The etchant sampled from the circulation line 10 via the line 14 is supplied to the absorptiometer 16. Further, the sample liquid of the etching solution processing tank 1 may be introduced into the absorptive photometer 16 by using a circulation pump for measurement.

The absorptiometer 16 is a continuous measurement of the absorbance of the etching solution. Thereby, the absorbance value related to the water concentration can be obtained. In addition, the final etchant is returned to the circulation line 10 via line 18.

Further, the absorptiometer 16 has compensating functions for minimizing measurement errors.

[absorbance controller 31]

The absorbance controller 31 is for managing the water concentration of the etching liquid in the etching liquid processing tank 1 within a certain range.

The absorbance photometer 16 and the flow rate adjusting valves 24 to 27 are connected to the absorbance controller 31. The absorbance controller 31 opens and closes at least one of the control flow rate adjusting valves 24 to 27 such that the absorbance input from the absorptive photometer 16 can form a predetermined target value (for example, 16.0 ± 2.0%). Thereby, the replenishing liquid corresponding to the controlled flow rate adjusting valve can be supplied into the etching liquid processing tank 1 to adjust the absorbance (that is, the water concentration). Further, the target value of the water concentration is set in advance in the controller 31 or the like based on the work performance or calculation.

[Example of operation]

Next, the operation of the etching processing apparatus having the above configuration will be described (the description of the operation overlapping the first embodiment will be omitted).

During the etching of the etching liquid processing unit A, mainly because moisture is evaporated together with the exhaust gas, or the components of nitric acid, acetic acid, and phosphoric acid are balanced, the water concentration of the etching liquid is reduced.

Then, in order to prevent a decrease in etching performance due to a decrease in the water concentration of the etching liquid, the following control is performed.

That is, the etching liquid sampled from the circulation line 10 via the line 14 is supplied to the absorptiometer 16.

The absorptiometer 16 is a continuous measurement of the absorbance of the etching solution. Thereby, the absorbance value related to the water concentration can be obtained. In addition, the final etchant is returned to the circulation line 10 via line 18.

The absorbance controller 31 controls at least one of the openable flow rate adjusting valves 24, 25, 27 in such a manner that the absorbance value input from the absorptive photometer 16 can form a predetermined target value (for example, 16.0 ± 2.0%).

For example, when the absorbance controller 31 detects that the absorbance value of the etching liquid is lower than the target value (for example, when the water concentration is lower than the target value due to evaporation of moisture), the absorbance value input from the absorptive photometer 16 can be formed into a predetermined value. The target value (for example, 16.0 ± 2.0%) is controlled to open the flow regulating valve 27. Further, for example, when the absorbance controller 31 detects that the absorbance value of the etching liquid rises more than the target value (for example, when the water concentration is higher than the target value due to evaporation of acetic acid), the absorbance value input from the absorptive photometer 16 is used. The flow rate adjustment valve that can open at least one of the flow regulating valves 24 and 25 is controlled in such a manner that a predetermined target value (for example, 16.0 ± 2.0%) can be formed.

Thereby, the replenishing liquid corresponding to the controlled flow rate adjusting valve flows into the circulation line 12 via the branch line and the junction line 28, and is mixed with the circulating etching liquid in the circulation line 12, and supplied thereto. The etching solution is treated in the tank 1.

Then, the absorbance controller 31 is controlled to turn off the flow regulating valve previously controlled to be turned on when the absorbance value input from the absorptive photometer 16 reaches a predetermined target value.

The water concentration of the etching liquid in the etching liquid processing tank 1 can be managed within a certain range by the control of the above-described absorbance controller 31. For example, even if the water concentration of the etching solution is mainly due to evaporation of moisture together with the exhaust gas, or changes in the etching performance due to changes in the composition of nitric acid, acetic acid, and phosphoric acid, the etching solution can be treated with the moisture of the etching solution in the bath 1. The concentration is managed within a certain range.

Further, in the present embodiment, generally, the liquid level of the etching liquid processing tank 1 is located near the position of the helium for overflow, and when the replenishing liquid is replenished, the degraded etching liquid overflows from the overflowing crucible. In addition, when the etching liquid in the etching liquid processing tank 1 is taken out to the outside of the substrate 6 and is reduced, it is slightly lower than the position of the crucible for overflow of the liquid level level.

[Third embodiment]

Fig. 5 is a system diagram for explaining an etching liquid management device according to a third embodiment of the present invention.

The etchant management device of the present embodiment is mainly applied to the etchant management device of the second embodiment, in which the management of the concentration of the etchant is important, and the management of the phosphoric acid concentration is important. F and the absorbance controller 32 omits the conductivity measuring unit D. Other configurations are the same as those of the second embodiment, and thus the description thereof will be omitted.

[Absorbance measuring unit F]

As a result of examining the relationship between the phosphoric acid concentration of the etching solution and the absorbance, the inventors have found that the measurement wavelength of the absorbance is suitably in the range of 2050 nm to 2300 nm in the near-infrared region, and particularly in the vicinity of 2101 nm.

6 is a graph showing the absorbance (the measurement wavelength λ = 2101 nm) and the phosphoric acid concentration corresponding to the absorbance after the actual measurement, in which the vertical axis represents the absorbance and the horizontal axis represents the phosphoric acid concentration. As is clear from Fig. 6, the absorbance (measurement wavelength λ = 2101 nm) and the phosphoric acid concentration corresponding to the absorbance are plotted along a straight line rising to the right. That is, it can be understood that there is a linear relationship between the absorbance (measurement wavelength λ = 2101 nm) and the phosphoric acid concentration, and the absorbance is detected based on the relationship, and the absorbance value related to the phosphoric acid concentration can be obtained.

The absorbance measuring unit F measures the absorbance of the etching liquid which is circulated in the etching liquid processing unit A based on the findings of the inventors, and obtains the absorbance value related to the phosphoric acid concentration.

The absorbance measuring unit F is provided with an absorptiometer 17 for measuring the absorbance (for example, the measurement wavelength λ = 2101 nm) of the etching liquid flowing in through the line 14 branched from the circulation line 10. Further, the absorptiometer 17 may be formed integrally with the absorptiometer 16, or may be configured separately.

The etchant sampled from the circulation line 10 via the line 14 is supplied to the absorptiometer 16 and is also supplied to the absorptiometer 17. Further, the sample liquid of the etching solution processing tank 1 may be introduced into the absorptive photometer 16 and the absorptive photometer 17 by using a circulation pump for measurement.

The absorptiometer 17 is a continuous measurement of the absorbance of the etching solution. Thereby, the absorbance value related to the phosphoric acid concentration can be obtained. In addition, the final etchant is returned to the circulation line 10 via line 18.

Further, the absorptiometer 17 has compensating functions for minimizing measurement errors.

[absorbance controller 32]

The absorbance controller 32 is for managing the phosphoric acid concentration of the etching liquid in the etching solution processing tank 1 within a certain range.

The absorbance photometer 17 and the flow rate adjusting valves 24 to 27 are connected to the absorbance controller 32. The absorbance controller 32 opens and closes at least one of the flow rate adjusting valves 24 to 27 so that the absorbance input from the absorptive photometer 17 can form a predetermined target value (for example, 70.0 ± 2.0%). Thereby, the replenishing liquid corresponding to the controlled flow rate adjusting valve is supplied into the etching liquid processing tank 1, and the absorbance (that is, the phosphoric acid concentration) is adjusted. Further, the target value of the phosphoric acid concentration is set in advance in the controller 32 or the like in accordance with the work performance or calculation.

[Example of operation]

Next, the operation of the etching processing apparatus having the above configuration will be described (the description of the operation overlapping with the second embodiment and the like is omitted).

During the etching of the etching solution processing unit A, phosphoric acid is consumed as an aluminum salt, but is concentrated as the nitric acid, acetic acid, and water evaporate, and the phosphoric acid concentration increases.

Then, in order to prevent a decrease in etching performance due to an increase in the phosphoric acid concentration of the etching liquid, the following control is performed.

That is, the etching liquid sampled from the circulation line 10 via the line 14 is supplied to the absorptive photometer 16, and is also supplied to the absorptive photometer 17.

The absorptiometer 17 is a continuous measurement of the absorbance of the etching solution. Thereby, the absorbance value related to the phosphoric acid concentration can be obtained. In addition, the final etchant is returned to the circulation line 10 via line 18.

The absorbance controller 32 is controlled to open at least one of the flow rate adjusting valves 24, 25, 27 in such a manner that the absorbance value input from the absorptive photometer 17 can form a predetermined target value (for example, 70.0 ± 2.0%).

For example, when the absorbance controller 32 detects that the absorbance value of the etching liquid is lower than the target value, the absorbance value input from the absorptive photometer 17 can be formed into a predetermined target value (for example, 70.0±2.0%). A flow regulating valve of at least one of the flow regulating valves 24, 25, 27 is opened.

Thereby, the replenishing liquid corresponding to the controlled flow rate adjusting valve flows into the circulation line 12 via the branch line and the junction line 28, and is mixed with the circulating etching liquid in the circulation line 12, and supplied thereto. The etching solution is treated in the tank 1.

Then, the absorbance controller 32 is controlled to turn off the flow regulating valve previously controlled to be turned on when the absorbance value input from the absorptive photometer 17 reaches a predetermined target value.

The phosphoric acid concentration of the etching liquid in the etching solution processing tank 1 can be managed within a certain range by the control of the above absorbance controller 32. For example, even if phosphoric acid is consumed as an aluminum salt and concentrated by evaporation of nitric acid, acetic acid, and water, the phosphoric acid concentration is increased, and the phosphoric acid concentration of the etching liquid in the etching solution processing tank 1 can be managed within a certain range.

Further, in the present embodiment, the liquid level of the etching liquid processing tank 1 is operated in the vicinity of the position of the overflowing crucible. When the replenishing liquid is replenished, the deteriorated etching liquid overflows from the overflowing crucible. In addition, when the etching liquid in the etching liquid processing tank 1 is taken out to the outside of the substrate 6 and is reduced, it is slightly lower than the position of the crucible for overflow of the liquid level level.

[Fourth embodiment]

Fig. 7 is a system diagram for explaining an etching liquid management device according to a fourth embodiment of the present invention.

In the etchant management device of the first embodiment, the etchant management device according to the third embodiment is mainly used in the viscous liquid management device according to the third embodiment. And an absorbance controller 32. Other configurations and operations are equivalent to those of the first embodiment, and thus the description thereof will be omitted.

[Fifth Embodiment]

Fig. 8 is a system diagram for explaining an etching liquid management device according to a fifth embodiment of the present invention.

When the etching liquid management device of the present embodiment is mainly applied to a management item in which the nitric acid concentration, the water concentration, and the phosphoric acid concentration are important, the etching liquid management device according to the second embodiment is added with the absorbance described in the third embodiment. The measuring unit F and the absorbance controller 32.

Other configurations and operations are equivalent to those of the second embodiment, and thus the description thereof will be omitted.

[Sixth embodiment]

Fig. 9 is a system diagram for explaining an etching liquid management device according to a sixth embodiment of the present invention.

The etching liquid management device of the present embodiment is mainly applied to a management item in which nitric acid concentration, water concentration, phosphoric acid concentration, and acetic acid concentration are important, or when the nitric acid concentration, the water concentration, the phosphoric acid concentration, and the acetic acid concentration are accurately measured and managed. In the etching liquid management device of the fifth embodiment, the multi-component calculator 33 is added. Other configurations are the same as those of the fifth embodiment, and thus the description thereof will be omitted.

[Multi-component calculator 33]

According to the experiment, the inventors have found that when nitric acid, phosphoric acid, or even acetic acid coexist, the conductivity of the diluted aqueous solution of the nitric acid concentration, the absorbance of the water concentration, the absorbance of the phosphoric acid concentration, and the density of the phosphoric acid concentration are not only one. The components are sensed and related to each other, so if multiple regression analysis is not used, the correct concentration cannot be obtained.

In addition, the inventors of the present invention have obtained the conductivity values of the nitric acid concentration of the liquid after the etching liquid in the etching solution for the aluminum film is diluted by three types of characteristic values (measured by pure water). The conductivity value, the absorbance value of the absorbance photometer that measures the water concentration of the etching solution, and the absorbance value (or the density value of the densitometer) of the spectrophotometer that measures the phosphoric acid concentration of the etching solution, using linear multiple regression analysis ( MLR-ILS) calculates the component concentration (nitric acid concentration, water concentration, and phosphoric acid concentration) of the etchant, and subtracts the calculated nitric acid concentration, water concentration, and phosphoric acid concentration from 100%, thereby calculating the acetic acid concentration.

Here, an example shows the calculation formula for the multiple regression analysis. Multiple regression analysis consists of two phases of correction and prediction. In the multiple regression analysis of the n component system, m calibration standard solutions were prepared. The concentration of the jth component present in the first solution is expressed as C _ij . Here, i=1~m and j=1~n. The p characteristic values (for example, the absorbance or conductivity of a certain wavelength) A _ik (k = 1 to p) were respectively measured for m standard solutions. The concentration data and the characteristic value data can be separately represented in the form of rows and columns (C, A).

The row and column to which the rank-and-column relationship is assigned is referred to as a correction rank, and is represented by a symbol S (S _kj ; k=1 to p, j=1 to n).

[Number 2] C = A. S

Known C and A (the content of A is not limited to a homogeneous measurement value, and even if a heterogeneous measurement value is mixed, for example, absorbance and conductivity), it is calculated by the rank calculation that S is a correction phase. At this time, it is necessary to p>=n and m>=np. Since each element of S is all unknown, it is preferable that m>np, which is the least squares calculation as it is next.

[Number 3] S = ( A ^T A ) ^-1 ( A ^T C )

Here, the superscript T means the transposed rank, and the superscript -1 means the retrograde column.

The p characteristic values are measured for the sample liquid whose concentration is unknown. If the value is Au (Au _k ;k=1~p), the concentration Cu obtained by multiplying S can be obtained (C u _j ;j= 1~n).

[Number 4] Cu=Au. S

This is the forecasting phase.

Table 1 shows the calculation results of the MLR-ILS calculation by the Leave-One-Out method, which is regarded as an unknown sample in the calibration standard 12 (12 calibration standard solutions). The calibration rank is obtained by the remaining 11 criteria, and the concentration of the hypothetical unknown sample is calculated and compared with the known value (weight modulation value). Table 1 shows the concentrations of phosphoric acid, nitric acid, and water determined by the near-infrared 2 wavelength (1931, 2101 nm) and 10-fold diluted conductivity.

The multi-component calculator 33 performs adjustment and control by calculating the component concentration of the correct etching liquid by the multi-component algorithm (multivariate regression analysis method, multivariate analysis method) based on the findings of the inventors described above.

The conductivity meter 15, the absorptiometer 16, and the absorptiometer 17 are connected to the multi-component calculator 33.

The multi-component calculator 33 is calculated by a multi-component algorithm (multiple regression analysis method, multivariate analysis method) from the conductivity and the absorbance input from the conductivity meter 15, the absorptiometer 16, and the absorptiometer 17. The concentration of the etchant (the concentration of nitric acid, the concentration of water, and the concentration of phosphoric acid) is further corrected by subtracting the calculated nitric acid concentration, water concentration, and phosphoric acid concentration from 100%, thereby calculating the acetic acid concentration, and the respective concentrations. The flow rate adjustment valve that can open at least one of the flow regulating valves 24, 25, 27 is controlled in such a manner that a predetermined target value can be formed. Thereby, the replenishing liquid corresponding to the controlled flow rate adjusting valve is supplied into the etching liquid processing tank 1, and the concentration of each component is adjusted.

[Example of operation]

Next, the operation of the etching processing apparatus having the above configuration will be described (the description of the operation overlapping with the first embodiment and the like is omitted).

During the etching of the etching liquid processing unit A as described above, mainly as the number of processed sheets of the substrate 6 increases, acetic acid evaporates together with the exhaust gas, so that the etching performance of the etching liquid gradually decreases.

Then, in order to prevent a decrease in etching performance due to a decrease in the acetic acid concentration of the etching liquid, the following control is performed.

The multi-component calculator 33 is calculated by a multi-component algorithm (multiple regression analysis method, multivariate analysis method) from the conductivity and the absorbance input from the conductivity meter 15, the absorptiometer 16, and the absorptiometer 17. The concentration of the etchant (the concentration of nitric acid, the concentration of water, and the concentration of phosphoric acid) is further corrected by subtracting the calculated nitric acid concentration, water concentration, and phosphoric acid concentration from 100%, thereby calculating the acetic acid concentration, and the respective concentrations. The flow rate adjustment valve that can open at least one of the flow regulating valves 24, 25, 27 can be controlled in such a manner that a predetermined target value (for example, the acetic acid concentration is a target value of 10.0 ± 1.0%) can be formed.

Thereby, the replenishing liquid corresponding to the controlled flow rate adjusting valve flows into the circulation line 12 via the branch line and the junction line 28, and is mixed with the circulating etching liquid in the circulation line 12, and supplied thereto. The etching solution is treated in the tank 1.

Then, the multi-component calculator 33 is controlled to turn off the flow regulating valve previously controlled to be turned on when the respective concentrations of the calculation reach a predetermined target value.

By the control of the above multi-component calculator 33, for example, even if the moisture concentration of the etching liquid is mainly due to evaporation of moisture together with the exhaust gas, or variation in the composition of nitric acid, acetic acid, or phosphoric acid, the etching performance may be changed. The water concentration of the etching liquid in the etching solution processing tank 1 is managed within a certain range.

Further, in the present embodiment, generally, the liquid level of the etching liquid processing tank 1 is operated in the vicinity of the position of the overflowing crucible.

As a result of the above-described embodiments, the inventors have found that the results of the respective control functions can be used in a complementary manner, and the composition of the etching liquid can be easily realized and the etching performance can be made uniform. Continuous operation and reduction in the amount of etchant used.

Further, in each of the above embodiments, the etching liquid is a solution using a solution of nitric acid, acetic acid, phosphoric acid, and pure water, but the present invention is not limited thereto. For example, the etching solution may be a solution containing at least one of organic acid, hydrochloric acid, sulfuric acid or perchloric acid, a solution of phosphoric acid, nitric acid and pure water, phosphoric acid or nitric acid, and the above organic acid is acetic acid or malonic acid. Aqueous solution.

As described above, according to the etching liquid management apparatus of each of the above embodiments, the etching liquid can be automatically controlled to a predetermined nitric acid concentration, acetic acid concentration, and phosphoric acid concentration, and the liquid supply to the etching liquid treatment tank can be appropriately managed. The etching performance is always constant, and the amount of the raw liquid used can be reduced, the work stop time can be greatly shortened, and the comprehensive manufacturing cost can be reduced.

According to the etching liquid management apparatus of each of the above embodiments, the second effect can be exhibited.

(1) By applying the etching liquid management apparatus of each of the above embodiments to an etching process of a semiconductor or a liquid crystal substrate, the nitric acid concentration, the water concentration, the phosphoric acid concentration, and the acetic acid concentration of the etching liquid can be continuously and continuously monitored, so that the precision can be accurately performed. The etchant is controlled to a certain concentration.

(2) Since the etching liquid can be controlled to a certain concentration with high precision, the control of the high-definition size of the aluminum film is fixed, and the control of the inclination angle of the aluminum film is also fixed, and the yield of the product is greatly increased. Upgrade. Even in the stable level, it can work continuously for a long time.

(3) Since the quality of the etching solution can be controlled to a certain extent and continuous operation is possible, there is no downtime for liquid replacement (Downtime) and unhelpful disposal, which can achieve a significant reduction in the amount of liquid used and the cost of the etching solution, and the operating rate. The overall effect of the increase in productivity and the low cost of unmanned labor costs.

Next, a description will be given of a modification.

As a result of examining the relationship between the phosphoric acid concentration of the etching solution and the density, the inventors have found that the density becomes higher as the concentration of phosphoric acid increases. Fig. 10 is a graph plotting the density after actual measurement and the concentration of phosphoric acid corresponding to the density in a coordinate system in which the vertical axis is the density and the horizontal axis is the phosphoric acid concentration. As is clear from Fig. 10, the density and the concentration of phosphoric acid corresponding to the density are plotted along a straight line rising to the right. That is, it can be understood that there is a linear relationship between the density and the phosphoric acid concentration, and the density is measured based on the relationship, and the phosphoric acid concentration can be measured.

According to the findings of the present inventors, instead of the absorptiometer 17 of each of the above embodiments, a densitometer 17' can be used. Thereby, the effects of the above embodiments can also be exhibited.

1. . . Etch treatment tank

3. . . Liquid level gauge

5. . . Roller conveyor

6. . . Substrate

7. . . Etch sprayer

8. . . Liquid pump

11. . . Circulating pump

15. . . Conductivity meter

16. . . Absorbance photometer

17. . . Absorbance photometer

17'. . . Densitometer

19. . . Drain pump

20. . . Etching stock solution supply tank

twenty one. . . Nitric acid raw liquid supply tank

twenty two. . . Etching new liquid supply tank

twenty four. . . Raw liquid flow regulating valve

25. . . Nitric acid flow control valve

26. . . New liquid flow control valve

27. . . Pure water flow control valve

29. . . Level level controller

30. . . Conductivity controller

31. . . Absorbance controller

32. . . Absorbance controller

33. . . Multi-component calculator

Fig. 1 is a system diagram of an etching liquid management device according to a first embodiment of the present invention.

2 is a graph showing the relationship between the nitric acid concentration of the etching solution and the conductivity of the diluent.

Fig. 3 is a system diagram of an etching liquid management device according to a second embodiment of the present invention.

4 is a graph showing the relationship between the water concentration of the etching solution and the absorbance.

Fig. 5 is a system diagram of an etching liquid management device according to a third embodiment of the present invention.

Fig. 6 is a graph showing the relationship between the phosphoric acid concentration of the etching solution and the absorbance.

Fig. 7 is a system diagram of an etching liquid management device according to a fourth embodiment of the present invention.

Fig. 8 is a system diagram of an etching liquid management device according to a fifth embodiment of the present invention.

Fig. 9 is a system diagram of an etching liquid management device according to a sixth embodiment of the present invention.

Fig. 10 is a graph showing the relationship between the phosphoric acid concentration of the etching solution and the density.

1. . . Etch treatment tank

2. . . Overflow slot

3. . . Liquid level gauge

4. . . Etching chamber cover

6. . . Substrate

7. . . Etch sprayer

8. . . Liquid pump

9. . . filter

10. . . Circulation line

11. . . Circulating pump

12. . . Circulation line

13. . . filter

14. . . Pipeline

15. . . Conductivity meter

16. . . Absorbance photometer

18. . . Pipeline

19. . . Drain pump

20. . . Etching stock solution supply tank

twenty one. . . Nitric acid raw liquid supply tank

twenty two. . . Etching new liquid supply tank

twenty three. . . Piping

twenty four. . . Raw liquid flow regulating valve

25. . . Nitric acid flow control valve

26. . . New liquid flow control valve

27. . . Pure water flow control valve

28. . . Confluence pipeline

30. . . Conductivity controller

31. . . Absorbance controller

32. . . Absorbance controller

34. . . Sampling line

35. . . Pure water supply line

36. . . Confluence pipeline

37. . . Pipeline

38. . . Sampling pump

39. . . Pure water pump

Claims (19)

An etching liquid management device for use in an etching liquid management device for an etching processing device, comprising: an etching liquid processing tank for storing an etching solution containing nitric acid; and circulating an etching liquid stored in the etching liquid processing tank The etching liquid circulation mechanism and the etching processing mechanism for transporting the substrate including the aluminum film etched by the etching liquid circulated by the etching liquid circulation mechanism are characterized in that the etching liquid sampling means is provided for the etching liquid Sampling means for diluting the etchant sampled by the etchant sampling means into a predetermined ratio by linear water relationship between the conductivity of the diluent and the nitric acid concentration of the etchant; The conductivity of the etching solution diluted by the diluting means is measured, thereby obtaining a nitric acid concentration in relation to the etching solution based on a linear relationship between the conductivity of the diluent and the nitric acid concentration of the etching solution. a conductivity value; and a replenishing liquid supply means, which is based on a conductivity value obtained by the above conductivity meter Supplying an etching liquid processing replenisher tank. An etching liquid management device for use in an etching liquid management device for an etching processing device, comprising: an etching liquid processing tank for storing an etching liquid; and an etching liquid for circulating an etching liquid stored in the etching liquid processing tank a circulation mechanism and an etching processing mechanism for transporting a substrate including an aluminum film etched by the etching liquid circulated by the etching liquid circulation mechanism, The method includes an etching liquid sampling means for sampling the etching liquid, and an absorption photometer for measuring the etching liquid sampled by the etching liquid sampling means by using a specific measurement wavelength in a range of 1920 to 1960 nm. The absorbance is obtained by taking a linear relationship between the absorbance of the etching liquid and the water concentration measured by the specific measurement wavelength to obtain an absorbance value related to the water concentration of the etching liquid; and a replenishing liquid supply means. The replenishing liquid is supplied to the etching liquid treatment tank based on the absorbance value obtained by the absorptiometer. An etching liquid management device for use in an etching liquid management device for an etching processing device, comprising: an etching liquid processing tank for storing an etching solution containing phosphoric acid; and circulating an etching liquid stored in the etching liquid processing tank The etching liquid circulation mechanism and the etching processing mechanism for transporting the substrate including the aluminum film etched by the etching liquid circulated by the etching liquid circulation mechanism are characterized in that the etching liquid sampling means is provided for the etching liquid Sampling; an absorptiometer that measures the absorbance of the etching solution sampled by the etching liquid sampling means by using a specific measurement wavelength in the range of 2050 to 2300 nm, thereby measuring the measured wavelength using the specific measurement wavelength. An absorbance value of the phosphoric acid concentration of the etching solution is obtained by a linear relationship between the absorbance of the etching solution and the phosphoric acid concentration; and a replenishing liquid supply means based on the absorbance value obtained by the absorptiometer The etchant treatment tank supplies the replenishing liquid. An etching liquid management device for use in an etching liquid management device for an etching processing device, comprising: an etching liquid processing tank for storing an etching solution containing phosphoric acid; and circulating an etching liquid stored in the etching liquid processing tank The etching liquid circulation mechanism and the etching processing mechanism for transporting the substrate including the aluminum film etched by the etching liquid circulated by the etching liquid circulation mechanism are characterized in that the etching liquid sampling means is provided for the etching liquid a sample; a density meter for measuring a density of an etchant sampled by the etchant sampling means, thereby obtaining a phosphoric acid concentration associated with the etchant based on a linear relationship between a density of the etchant and a phosphoric acid concentration; a density value; and a replenishing liquid supply means for supplying a replenishing liquid to the etching liquid processing tank based on a density value obtained by the densitometer. An etching liquid management device for use in an etching liquid management device for an etching processing device, comprising: an etching liquid processing tank for storing an etching liquid containing nitric acid and phosphoric acid; and etching for storing in the etching liquid processing tank The etching cycle mechanism for the liquid circulation and the etching treatment mechanism for transporting the substrate including the aluminum film etched by the etching liquid circulated by the etching liquid circulation mechanism are characterized in that the etching liquid sampling means is provided, and the etching is performed by etching The liquid is sampled; the dilution means is to dilute the etching liquid sampled by the above etching liquid sampling means with pure water; a conductivity meter for measuring a conductivity of an etching solution diluted by the diluting means to obtain a conductivity value of a nitric acid concentration of the etching solution; and an absorptiometer for measuring the etching liquid by the etching liquid The absorbance of the etching liquid sampled by the means is obtained, thereby obtaining an absorbance value related to the water concentration of the etching liquid; and the absorptiometer is configured to measure the absorbance of the etching liquid sampled by the etching liquid sampling means, thereby obtaining correlation The absorbance value of the phosphoric acid concentration of the etching solution, or the density meter, which measures the density of the etching solution sampled by the etching liquid sampling means, thereby determining a linear relationship between the density of the etching liquid and the phosphoric acid concentration. To obtain a density value of the phosphoric acid concentration associated with the etching solution; a component concentration calculation method using a multi-component algorithm (multivariate regression analysis method; multivariate analysis method), which is obtained from the above conductivity meter a conductivity value of a nitric acid concentration, an absorbance value related to a water concentration obtained by the above-mentioned absorptiometer, and by the above The concentration of the component of the etching solution obtained by the photometer or the density meter or the density value obtained by the density meter; and the replenishing liquid supply means based on the composition calculated by the component concentration calculation means At the concentration, the replenishing liquid is supplied to the etching liquid treatment tank. The etching liquid management device according to any one of the first to fifth aspect, wherein the etching liquid is an aqueous solution containing phosphoric acid or nitric acid. An etchant management device according to item 6 of the patent application, wherein The etching solution is an aqueous solution containing at least one of organic acid, hydrochloric acid, sulfuric acid, and perchloric acid. The etching solution management device according to claim 7, wherein the organic acid is acetic acid or malonic acid. An etching solution concentration measuring device is an etching liquid concentration measuring device used in an etching processing device, comprising: an etching liquid processing tank for storing an etching liquid containing nitric acid and phosphoric acid; and storing the etching liquid processing tank in the etching liquid processing tank An etching liquid circulation mechanism for etching the etching liquid, and an etching processing mechanism for transporting the substrate including the aluminum film etched by the etching liquid circulated by the etching liquid circulation mechanism, characterized in that the etching liquid sampling means is provided The etching solution is sampled; the dilution means is to dilute the etching liquid sampled by the etching liquid sampling means by pure water; and the conductivity meter measures the conductivity of the etching liquid diluted by the dilution means, Thereby, the conductivity value of the nitric acid concentration of the etching liquid is obtained; and the absorptiometer measures the absorbance of the etching liquid sampled by the etching liquid sampling means, thereby obtaining the water concentration associated with the etching liquid. Absorbance value; an absorptiometer that measures the absorbance of the etchant sampled by the etchant sampling means, Related to the above etching solution to obtain absorbance values of the concentration of phosphoric acid, or a densitometer, the density thereof was measured based etching liquid sample by means of the etching solution sampled, whereby the etching solution in accordance with the The linear relationship between density and phosphoric acid concentration to obtain the density value of the phosphoric acid concentration associated with the above etching solution; and the component concentration calculation method, which utilizes a multi-component algorithm (multivariate regression analysis method, multivariate analysis method) a conductivity value obtained by the conductivity meter relating to a nitric acid concentration, an absorbance value obtained by the absorption spectrophotometer relating to a water concentration, and a correlation obtained by the above-described absorptiometer or the above densitometer The absorbance value or the density value of the phosphoric acid concentration is used to calculate the component concentration of the above etching liquid. A method for measuring a nitric acid concentration of an etching solution, characterized in that the etching solution containing nitric acid is diluted with pure water to have a linear relationship between the conductivity of the diluent and the nitric acid concentration of the etching solution, and the conductivity is used. The conductivity of the diluted etching liquid is measured, and the conductivity value of the nitric acid concentration of the etching liquid is obtained based on a linear relationship between the conductivity of the diluent and the nitric acid concentration of the etching liquid. A method for measuring a water concentration of an etching solution, wherein the absorbance of the etching liquid is measured by a specific measurement wavelength in a range of 1920 to 1960 nm using an absorption photometer, and the above-described measurement is performed based on the specific measurement wavelength. The linear relationship between the absorbance of the etching solution and the water concentration is used to obtain an absorbance value related to the water concentration of the etching liquid. A method for measuring a phosphoric acid concentration of an etching solution, characterized in that the absorbance of an etching solution containing phosphoric acid is measured by a specific measurement wavelength in a range of 2050 to 2300 nm using an absorption photometer, thereby The absorbance value of the phosphoric acid concentration of the etching liquid is obtained by a linear relationship between the absorbance of the etching liquid and the phosphoric acid concentration measured by the specific measurement wavelength described above. A method for measuring a phosphoric acid concentration of an etching solution, characterized in that a density of an etching solution containing phosphoric acid is measured using a densitometer, thereby obtaining a correlation with the etching liquid according to a linear relationship between a density of the etching solution and a phosphoric acid concentration. The density value of the phosphoric acid concentration. A method for measuring a component concentration of an etching solution, characterized in that a multi-component algorithm (multivariate regression analysis method, multivariate analysis method) is used to dilute an etching solution containing nitric acid and phosphoric acid with pure water, and is determined by using a conductivity meter The conductivity value obtained by the conductivity of the diluted etching liquid, the absorbance value obtained by measuring the absorbance of the etching liquid using an absorption photometer, and the absorbance of the etching liquid using an absorption photometer The obtained absorbance value related to the phosphoric acid concentration or the density of the etching liquid is measured using a densitometer, and the density value related to the phosphoric acid concentration obtained by the linear relationship between the density of the etching liquid and the phosphoric acid concentration is calculated. The concentration of the component of the etchant. An apparatus for measuring a nitric acid concentration of an etching solution, comprising: an etching solution dilution unit for diluting a nitric acid-containing etching with pure water so as to have a linear relationship between a conductivity of the diluent and a nitric acid concentration of the etching solution; a ratio of the liquid to a predetermined ratio; and a conductivity meter for measuring the conductivity of the diluted etching solution, whereby the conductivity of the diluent is between the conductivity of the etching solution and the concentration of the nitric acid of the etching solution The linear relationship is obtained to obtain a conductivity value related to the nitric acid concentration of the above etching liquid. An apparatus for measuring a moisture concentration of an etching liquid, comprising: an absorptiometer that measures the absorbance of the etching liquid by a specific measurement wavelength in a range of 1920 to 1960 nm, thereby measuring the measurement wavelength by the specific measurement wavelength The linear relationship between the absorbance of the etching liquid and the water concentration is used to obtain an absorbance value related to the water concentration of the etching liquid. An apparatus for measuring a phosphoric acid concentration of an etching solution, comprising: an absorptiometer that measures an absorbance of an etching solution containing phosphoric acid by a specific measurement wavelength in a range of 2050 to 2300 nm, whereby the specific measurement is used. The linear relationship between the absorbance of the etching liquid and the phosphoric acid concentration after the wavelength measurement is performed to obtain an absorbance value related to the phosphoric acid concentration of the etching liquid. An apparatus for measuring a phosphoric acid concentration of an etching solution, comprising: a densitometer for measuring a density of an etching solution containing phosphoric acid, wherein the etching is performed in accordance with a linear relationship between a density of the etching solution and a phosphoric acid concentration; The density value of the phosphoric acid concentration of the liquid. A component concentration measuring device for an etching liquid, comprising: an etching solution dilution portion for diluting an etching liquid containing nitric acid and phosphoric acid with pure water; and a conductivity meter for measuring the diluted etching liquid Conductivity, thereby obtaining a conductivity value related to the nitric acid concentration of the etching solution; The first absorptiometer is configured to obtain an absorbance value related to a water concentration of the etching liquid by measuring an absorbance of the etching liquid, and a second absorptiometer is configured to measure an absorbance of the etching liquid. Obtaining an absorbance value related to the phosphoric acid concentration of the etching liquid, or a density meter for measuring the density of the etching liquid, thereby obtaining the etching according to a linear relationship between the density of the etching liquid and the phosphoric acid concentration. a density value of a phosphoric acid concentration of a liquid; and a multi-component calculator which uses a multi-component algorithm (multivariate regression analysis method, multivariate analysis method) to obtain a conductivity value obtained by measurement using the above conductivity meter, An absorbance value related to a water concentration obtained by measurement using the first absorption photometer, and an absorbance value obtained by measurement using the second absorption photometer, which is related to a phosphoric acid concentration, or using the density meter described above. The measurement is performed by calculating the density value of the phosphorus concentration based on the linear relationship between the density of the etching solution and the phosphoric acid concentration. Concentrations of the components of the etching solution.