TW201606134A - Etching solution managing apparatus, dissolved metal concentration measuring apparatus and dissolved metal concentration measuring method - Google Patents

Abstract

This invention is to provide an etching solution managing apparatus, a dissolved metal concentration measuring apparatus and a dissolved metal concentration measuring method for monitoring content concentration of an etching solution and dissolved metal concentration and automatically replenishing supplemental solution by maintaining the content concentration constant while separating and recycling the dissolved metal. The solution of this invention is the apparatus or method mentioned above, comprising: a first physical property measuring means for measuring the first physical property related to the acid concentration in the etching solution; a second physical property measuring means for measuring the second physical property related to the dissolved metal concentration; a supplemental solution transport controlling means for controlling the transport of the replenished supplemental solution according to the relationship between the acid concentration and the first physical property and the measurement result of the first physical property; and a dissolved metal recycling and removing means for recycling and removing dissolved metal according to the relationship between the dissolved metal concentration and the second physical property and the measurement result of the second physical property.

Description

Etching liquid management device, dissolved metal concentration measuring device, and method for measuring dissolved metal concentration

The present invention relates to an etching liquid management device, a dissolved metal concentration measuring device, and a method for measuring a dissolved metal concentration, and more particularly to an etching process for adjusting a concentration of an etching liquid which changes in concentration with time due to an etching process, and recovering and removing dissolved metal. Liquid management device, dissolved metal concentration measuring device, and method for measuring dissolved metal concentration.

In the etching of a process of a semiconductor or a liquid crystal substrate, an etching liquid composed of a liquid appropriately conditioned according to an etching target is circulated or stored in an etching bath, and is repeatedly used. When the etching target is a metal compound film such as a metal film or a metal alloy film or a metal oxide film, an etching solution made of an acid or an oxidizing agent is mainly used, and, as the case may be, a surfactant may also be used. Or a liquid composition of various additives such as decomposition inhibitors.

For example, as an etching solution for a copper/copper alloy film, an aqueous solution containing sulfuric acid, hydrogen peroxide or the like is often used as a chromium film/chromium alloy. As the etching solution for a film, an aqueous solution containing cerium ammonium nitrate (diammonium nitrate (IV)) and nitric acid as a main component is often used, and as an etching liquid for a transparent conductive film, oxalic acid and a surfactant are often used. Aqueous solution.

When such a metal-based etching film is etched, as the etching process progresses, the main component of the etching liquid is consumed by the etching reaction, and the metal component from the film to be etched is eluted and accumulated in the etching liquid. . The dissolved metal accumulated in the etching liquid tends to suppress further elution of the metal component from the film to be etched, and the etching rate is lowered to deteriorate the performance of the etching liquid. Further, since the etching tank is sucked and exhausted so that the harmful gas does not leak to the outside, a part of components such as moisture or acid are lost in volatilization accompanying the exhaust gas, and the dissolved metal in the etching liquid is relatively concentrated. Therefore, the liquid composition of the etching liquid changes with time and is not stabilized, and the dissolved metal increases, causing a decrease in the performance of the etching liquid.

From this point of view, in the past, if the performance of the etching liquid was lowered and it became unusable, the liquid was discarded and a new etching liquid was exchanged. However, this method generates a large amount of waste liquid, and at the same time, since the production line must be stopped at each exchange, the productivity is deteriorated, and the concentration of the etching liquid for etching treatment is also repeatedly changed within a specific range, and the performance of the etching liquid is Maintenance management cannot be met.

When the etchant is continuously and automatically managed, the concentration of the original component of the etchant is constantly monitored, and the etchant solution or the new solution or the water is supplied as a replenishing solution as needed. The etchant management device whose concentration is managed at a specified value (for example, refer to Patent Document 1). Also, there will be dissolved metals The concentration is included in the management item, and the device for measuring the concentration of the etching liquid and the concentration of the dissolved metal, and discharging the etching liquid or replenishing the replenishing liquid to manage the etching liquid (for example, refer to Patent Document 2).

Prior technical literature Patent literature

Patent Document 1 JP-A-2004-137519

Patent Document 2

However, in general, the etchant is managed by the supply of the replenishing liquid, and although the concentration management of the etchant component is excellent, it is only diluted with the eluted component from the film to be etched. Therefore, if the concentration of the eluted component is managed within the specified range in addition to the etching liquid component, the total amount of the etching liquid is inevitably increased unnecessarily. In this regard, in the invention described in Patent Document 2, by providing a mechanism for discharging the etching liquid, it is possible to reduce the concentration of the dissolved metal while suppressing an increase in the amount of liquid. However, since not only the metal is dissolved but also the active component in the etching liquid is discharged in a large amount at the same time, the amount of the waste liquid is large, and in order to replenish the active ingredient which is reduced by being discharged, it is necessary to supply the replenishing liquid in a large amount. These problems are particularly pronounced when the solubility of the dissolved metal relative to the etchant is low.

Examples of the low solubility of the metal component eluted from the film to be etched in the etching solution include etching of indium tin oxide (ITO), indium zinc oxide (IZO), indium gallium oxide (IGO), or indium gallium zinc oxide (IGZO). Transparent An oxalic acid-based etching solution for a conductive film or an oxide semiconductor film. At this time, when the etching treatment is repeated, the dissolved indium is precipitated in the etching liquid, which causes the deterioration of the product quality due to the occurrence of etching residue or the like. Therefore, it is desirable to properly manage the concentration of dissolved indium, and it is preferable to separate and remove the dissolved indium from the etching liquid to maintain the performance of the etching liquid.

Further, when the metal dissolved in the etching solution is a valuable metal such as indium or copper, it is not required to be discarded as an etching waste liquid, and is required to be separated and recovered. However, in the field of etchant management, it has only been appropriate to replenish the replenishing liquid and discharge the degraded liquid. It is not intended to automatically separate and recover the dissolved metal from the etching solution by detecting the dissolved metal concentration. Etching solution.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a method of automatically replenishing a replenishing liquid by monitoring the concentration of a component of the etching liquid and monitoring the concentration of the dissolved metal so that the concentration of each component of the etching liquid becomes a management value. An etchant management device that separates and recovers dissolved metals. Further, a dissolved metal concentration measuring device for measuring the dissolved metal concentration in the etching solution and a method for measuring the dissolved metal concentration are provided.

That is, an object of the present invention is to automatically adjust the component concentration so that the concentration of the component of the etching liquid is within the controlled concentration range, and to constantly maintain the etching liquid in the desired liquid property. Further, the dissolved metal is recovered and removed according to the dissolved metal concentration of the etching liquid, and the solubility of the metal is prevented from being lowered. Further, the amount of the etching liquid is not excessively increased, and the amount of the etching waste liquid is reduced to the limit, and the amount of the replenishing liquid to be replenished is also minimized, and the dissolved valuable metal is efficiently recovered.

In order to achieve the above object, the present invention provides an etching liquid management apparatus which is an etching liquid management apparatus which manages an etching liquid containing an acid and repeatedly used in etching a metal film or a metal compound film, and is characterized in that: The first physical property measuring means for determining the first physical property value of the etching liquid physical property value and the acid concentration in the etching liquid; and determining the physical property value of the etching liquid is related to the concentration of the metal dissolved in the etching film from the metal film or the metal compound film The second physical property measuring means of the second physical property value; the acid concentration is within the managed concentration range based on the correlation between the acid concentration in the etching solution and the first physical property value and the measurement result of the first physical property measuring means The method of controlling the replenishing liquid to be supplied to the replenishing liquid of the etching liquid; and determining the correlation between the dissolved metal concentration in the etching liquid and the second physical property value and the second physical property measuring means As a result, the dissolution of the dissolved metal in the etching solution is recovered from the etching solution in such a manner that the metal concentration becomes less than the threshold of the managed concentration. Removal means for metal recovery.

The etchant management device according to the present invention includes a first physical property value measuring means for measuring a first physical property value relating to an acid concentration in the etching solution, and a correlation between an acid concentration in the etching solution and a first physical property value. And the measured value of the first physical property measuring means supplies the replenishing liquid so that the acid concentration becomes within the managed range, so that the acid concentration can be made into the specified range. Further, the supply of the replenishing liquid can calculate the acid concentration so that the acid concentration is within the managed range, and the acid concentration can be within the managed range by setting the first physical property value within a predetermined range.

The value of the acid concentration to be managed may be within the range of the concentration of the managed acid, and is preferably a value near the center in the range. Further, the management range is preferably set in advance, but may be appropriately changed during the operation of the apparatus.

Further, by providing the second physical property value measuring means related to the dissolved metal concentration in the etching liquid, the correlation between the dissolved metal concentration and the second physical property value obtained in advance is used based on the measurement result of the second physical property measuring means. The dissolved metal concentration of the etching solution can be obtained from the second physical property value. Therefore, based on the obtained dissolved metal concentration value, the dissolved metal concentration can be recovered and removed by controlling the dissolved metal concentration in the etching solution to be less than or equal to the threshold value of the managed concentration. Further, the recovered metal is recovered and removed, and the dissolved metal concentration can be calculated so that the dissolved metal concentration is equal to or lower than the managed threshold value, and the dissolved metal can be made to have the second physical property value equal to or less than a predetermined threshold value. The concentration is below the managed threshold.

In this way, by setting the acid concentration within a predetermined range, the liquid property of the etching solution for the metal film or the metal compound film can be fixed. Further, by fixing the acid concentration, the concentration of the metal dissolved in the etching liquid can be accurately determined from the second physical property value related to the dissolved metal concentration, and the self-etching performance can be lowered. Recycled to remove dissolved metals.

In order to achieve the above object, the present invention provides an etching liquid management apparatus which is an etching liquid management apparatus which manages an etching liquid containing an acid and an oxidizing agent and repeatedly used in etching a metal film or a metal compound film, and is characterized by comprising: Measuring the first physical property value of the first physical property value related to the acid concentration in the etching liquid which is the physical property value of the etching liquid a means for measuring a second physical property value which is a second physical property value relating to a concentration of a metal dissolved in a metal film or a metal compound film in the etching liquid, and a physical property value of the etching liquid and the etching The third physical property measuring means for the third physical property value related to the concentration of the oxidizing agent in the liquid; the correlation between the acid concentration in the etching solution and the first physical property value and the measurement result of the first physical property measuring means The method of controlling the concentration range, and the correlation between the oxidant concentration in the etching solution and the third physical property value and the measurement result of the third physical property measuring means, and controlling the oxidizing agent concentration to be within the managed concentration range a replenishing liquid transport control means for replenishing the replenishing liquid to the etching liquid; and a metal concentration according to a correlation between the dissolved metal concentration in the etching liquid and the second physical property value and a measurement result of the second physical property measuring means The means for recovering and removing the dissolved metal from the dissolved metal in the etching solution is recovered from the etching solution in such a manner that it is equal to or less than the threshold value of the managed concentration.

According to the etching liquid management apparatus of the present invention, the correlation between the acid concentration in the etching solution and the first physical property value, the measured value of the first physical property measuring means, the oxidizing agent concentration in the etching solution, and the third physical property value The relationship between the correlation and the measured value of the third physical property measuring means is such that the acid concentration and the oxidizing agent concentration are added to the managed range, so that the acid concentration and the oxidizing agent concentration can be set to a predetermined range.

Further, by setting the acid concentration and the oxidizing agent concentration to a predetermined range, the dissolved metal concentration of the etching liquid can be accurately obtained from the second physical property value relating to the dissolved metal concentration in the etching liquid. Therefore, according to this The obtained dissolved metal concentration value can be controlled by recovering and removing the dissolved metal so that the dissolved metal concentration in the etching solution becomes equal to or less than the threshold value of the managed concentration.

In order to achieve the above object, the present invention provides an etching liquid management apparatus which is an etching liquid management apparatus which manages an etching liquid containing an acid and repeatedly used in etching a metal film or a metal compound film, and is characterized in that: a first physical property measuring means for determining a physical property value of at least one of the etching liquids and an acid concentration in the etching liquid; and measuring at least a physical property of the etching liquid and a metal dissolved in the etching film from the metal film or the metal compound film The second physical property measuring means having the second physical property value according to the concentration; the first physical property value measured by the first physical property measuring means and the second physical property value measured by the second physical property measuring means The multivariate analysis method calculates a calculation method of the acid concentration in the etching solution and the dissolved metal concentration in the etching solution, and controls the supply so that the acid concentration in the etching liquid calculated by the calculation means is within the managed concentration range. a replenishing liquid transport control means for transporting the replenishing liquid to the etching liquid; and a dissolved gold in the etching liquid calculated by the arithmetic means The method for recovering and removing dissolved metals of the dissolved metal in the etching solution is recovered from the etching solution in such a manner that the concentration is below the threshold of the managed concentration.

According to the etching liquid management apparatus of the present invention, the first physical property measuring means and the second physical property measuring means for measuring two different physical property values of the etching liquid related to the acid concentration and the dissolved metal concentration of the etching liquid are measured. Since the first physical property value and the second physical property value of the etching solution are obtained, the acid concentration of the etching solution and the dissolved metal concentration can be obtained by multivariate analysis. degree. The first measurement means and the second measurement means are continuous or repeated, and the first physical property value and the second physical property value of the etching liquid are measured, and the acid concentration of the etching liquid calculated by the multivariate analysis method is used as the acid of the etching liquid. The replenishment liquid is supplied in such a manner that the concentration becomes within the range of the controlled concentration, and the acid concentration of the etching liquid can be controlled to make the acid concentration within a specified range.

Similarly, the dissolved metal concentration of the etching solution can be calculated by the multivariate analysis method, and the dissolved metal concentration calculated by the operation can be operated by the dissolved metal recovery means to make the dissolved metal in the etching solution a managed threshold. Below the value. Therefore, by controlling the acid concentration to be fixed, the liquid property of the etching liquid is fixed, and the dissolved metal concentration is equal to or less than the threshold value, whereby the solubility of the metal in the etching liquid can be maintained.

Further, in the multivariate analysis method (for example, the multiple regression analysis method), one physical property value of the etching liquid is not related to the concentration of one component of the etching liquid, but one physical property value is assumed to be a majority. The etching solution obtained by the influence of the components. Therefore, each of the first physical property measuring means and the second physical property measuring means is a means for measuring at least the first physical property value and the second physical property value relating to the acid concentration and the dissolved metal concentration in the etching liquid, and the first physical property value. The means of measurement is not a means of measuring only the physical property values associated with the acid concentration. In other words, the first physical property value measured by the first physical property measurement means may be a physical property value related to the dissolved metal concentration.

In order to achieve the above object, the present invention provides an etching liquid management apparatus which is an etching liquid management apparatus which manages an etching liquid containing an acid and an oxidizing agent and repeatedly used in etching a metal film or a metal compound film, and is characterized by comprising: Determination of the physical properties of the etching solution a first physical property measuring means for reducing a first physical property value related to an acid concentration in an etching solution; and measuring a physical property value of the etching liquid at least in relation to a metal concentration dissolved in the metal film or the metal compound film in the etching solution a second physical property measuring means for measuring a physical property value; and a third physical property measuring means for determining a third physical property value relating to at least an oxidizing agent concentration in the etching liquid; and the first physical property measuring means The first physical property value measured, the second physical property value measured by the second physical property value measuring means, and the third physical property value measured by the third physical property value measuring means are used to calculate the acid concentration in the etching solution by multivariate analysis. a calculation means for the dissolved metal concentration in the etching solution and the oxidant concentration in the etching solution; the acid concentration in the etching solution calculated by the calculation means is within the managed concentration range, and the etching calculated by the calculation means The concentration of the oxidant in the liquid is within the range of the controlled concentration, and the replenishing liquid delivery control means for supplying the replenishing liquid to the etching liquid is controlled; and The etchant is calculated in calculation means a concentration of dissolved metal concentrations threshold value managed by way of the following, from the etchant recovered etchant to remove dissolved metals dissolved metal recovery removal means.

According to the etching liquid management apparatus of the present invention, the first physical property measuring means and the second physical property value are measured by measuring three different physical property values of the etching liquid related to the acid concentration, the dissolved metal concentration, and the oxidizing agent concentration of the etching liquid. The means and the third physical property measuring means measure the first physical property value, the second physical property value, and the third physical property value of the etching liquid. Therefore, the physical property value measured from the above can be accurately determined by the multivariate analytical method. The acid concentration, the dissolved metal concentration, and the oxidant concentration in the etching solution were calculated.

The acid concentration and the oxidant concentration calculated by the arithmetic means of the multivariate analysis method are used to supply the replenishing liquid so that the acid concentration and the oxidizing agent concentration of the etching liquid become within the managed concentration range, thereby controlling the acid concentration and the oxidizing agent concentration of the etching liquid. The acid concentration and the oxidant concentration can be made within a specified range.

Similarly, by operating the dissolved metal recovery and removal means based on the dissolved metal concentration calculated by the calculation means, the dissolved metal concentration in the etching liquid can be equal to or less than the managed threshold.

Therefore, by controlling the acid concentration and the oxidant concentration to be fixed, the liquid property of the etching liquid is fixed, and the concentration of the dissolved metal is equal to or less than the threshold value, whereby the solubility of the metal in the etching liquid can be maintained.

Further, each of the first physical property measuring means, the second physical property measuring means, and the third physical property measuring means measures a first physical property value relating to at least an acid concentration, a dissolved metal concentration, and an oxidizing agent concentration in the etching liquid. 2 means of physical property value and third physical property value. Therefore, the first physical property value, the second physical property value, and the third physical property value measured by the first physical property value measuring means, the second physical property value measuring means, and the third physical property value measuring means may be other than the etching liquid. The ingredients have related physical properties.

In another aspect of the present invention, the first physical property measuring means is preferably a conductivity meter for measuring a conductivity value of the etching liquid as a first physical property value, or a supersonic conduction velocity of the etching liquid as a first physical property value. Ultrasonic concentration meter.

According to the acid concentration of the acid-containing etching liquid, the conductivity value of the etching liquid, or the ultrasonic conduction rate of the etching liquid, the conductivity is measured by the conductivity meter or the ultrasonic concentration meter as the first physical property measuring means. The acid concentration can be measured with high precision.

In another aspect of the present invention, the second physical property measuring means is preferably a densitometer that measures a density value of the etching liquid as a second physical property value or an absorbance value of the etching liquid as a second physical property value.

According to the dissolved metal concentration of the etching liquid, the density of the etching liquid, or the absorbance value of the specific wavelength of the etching liquid, the dissolved metal can be accurately measured by using a densitometer or an absorptiometer as the second physical property measuring means. concentration.

In another aspect of the present invention, the third physical property measuring means is preferably an ultrasonic spectrophotometer that measures an absorbance value of the etching liquid as a third physical property value, and an ultrasonic wave that measures the ultrasonic conduction velocity of the etching liquid as a third physical property value. A densitometer, a density meter for measuring the density value of the etching solution as a third physical property value, or an oxidation-reduction potentiometer for measuring an oxidation-reduction potential of the etching liquid as a third physical property value.

According to this aspect, the third physical property measuring means for measuring the concentration of the oxidizing agent is an etching liquid measured by the measuring means by using an absorptiometer, an ultrasonic concentration meter, a densitometer, or a redox potentiometer. Since the absorbance value, the ultrasonic conduction velocity, the density value, and the oxidation-reduction potential of the specific wavelength are correlated with the oxidant concentration, the concentration of the oxidant can be measured with high precision.

In other aspects of the invention, the means for removing dissolved metal is preferably a crystallization apparatus or an electrolysis apparatus.

The solubility of the metal component eluted from the metal film or the metal compound film to the etching liquid in the etching liquid varies depending on various liquid conditions of the etching liquid. By using a crystallization apparatus as a dissolved gold It is a recovery and removal apparatus, and the crystallization conditions are changed, and the solubility of the metal in the etching liquid can be lowered, and the dissolved metal can be precipitated as a crystal of a metal salt or the like. Further, since the dissolved metal component in the etching liquid can be precipitated as a metal on the surface of the electrode by electrolytic treatment, separation and removal of the dissolved metal can be performed by using an electrolysis device.

In other aspects of the invention, the crystallization apparatus is preferably a screw conveyor type crystallization apparatus.

According to this aspect, by using a screw conveyor type crystallization apparatus as the crystallization apparatus, the crystallization crystallization of the dissolved metal deposited and deposited in the etching liquid can be recovered and removed without a discharge operation. Further, the crystallization product is precipitated in the etching liquid which has been retained in the large crystallization tank in the past, and the crystallization is directly and automatically recovered from the etching liquid as a method in which the sludge is discharged from the lower portion of the crystallization tank. At the same time, the large crystallization tank can be used, and the space saving of the device can be performed.

In other aspects of the invention, the metal compound film is preferably a metal alloy film, a metal oxide film, a metal nitride film, a metal carbide film, a metal vulcanization film, a metal phosphating film or a metal boride film.

In other aspects of the invention, the metal oxide film is preferably an ITO film, an IZO film, an IGO film or an IGZO film.

In another aspect of the invention, the etching solution preferably contains at least one of hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid, hydrofluoric acid, perchloric acid, and an organic acid as an aqueous acid solution.

In other aspects of the invention, the organic acid is preferably at least one of oxalic acid, acetic acid, citric acid, and malonic acid.

In other aspects of the invention, the etching solution preferably contains hydrogen peroxide, ozone, nitric acid, persulfuric acid, ammonium cerium nitrate, iron chloride (iron (III) chloride), and copper chloride (copper chloride ( At least one of II)) is used as an aqueous solution of an oxidizing agent.

The above is exemplified as a metal compound film or a metal oxide film to be etched. Moreover, it is an illustration of the acid component contained in an etching liquid. Moreover, it is an illustration of the oxidizing agent component contained in an etching liquid. According to this aspect, the use of the above-described component as the film to be etched, the acid component, and the oxidant component can be correlated with the first physical property value, the second physical property value, and the third physical property value, and the etching can be performed with high precision. The acid concentration in the liquid, the dissolved metal concentration, and the oxidant concentration.

In order to achieve the above object, the present invention provides a dissolved metal concentration measuring apparatus which is a measuring apparatus for measuring a dissolved metal concentration which measures a concentration of a metal which is dissolved in an etching liquid which is repeatedly used in etching of a metal film or a metal compound film, It is characterized by comprising: an acid concentration measuring means for measuring an acid concentration in the etching liquid; and controlling the replenishing liquid supplied to the etching liquid so that the acid concentration in the etching liquid measured by the acid concentration measuring means is within the controlled concentration range a method for measuring a physical property of a transporting liquid; a method for measuring a physical property value of a physical property value relating to a dissolved metal concentration in an etching solution; and a method according to a concentration between a dissolved metal concentration and a physical property value in the etching solution The correlation relationship and the measurement result of the physical property value measuring means are measures for measuring the dissolved metal concentration of the concentration of the dissolved metal in the etching solution.

According to the dissolved metal concentration measuring device of the present invention, the etching liquid can be obtained by the acid concentration measuring means and the replenishing liquid feeding control means The acid concentration in the range is within the managed concentration range. Further, by setting the acid concentration in the etching liquid to the controlled concentration range, the metal concentration can be obtained by using the correlation between the physical property value and the metal concentration in relation to the dissolved metal concentration in the etching liquid. Therefore, by measuring the physical property value related to the dissolved metal concentration, the concentration of the dissolved metal in the etching can be measured with high precision.

In order to achieve the above object, the present invention provides a method for measuring a dissolved metal concentration, which is a method for measuring a dissolved metal concentration of a concentration of a metal dissolved in an etching solution containing an acid and repeatedly used in etching of a metal film or a metal compound film, The method includes a step of measuring an acid concentration for measuring an acid concentration in the etching solution, and controlling a replenishing liquid to be supplied to the etching liquid so that an acid concentration in the etching liquid measured by the acid concentration measuring means is within a controlled concentration range. a replenishing liquid transport control step of transporting; determining a physical property value measuring step of a physical property value relating to a dissolved metal concentration in the etching liquid, which is a physical property value of the etching liquid; and, depending on a dissolved metal concentration and a physical property value in the etching liquid The correlation relationship and the measurement result of the physical property value measuring step are measures for measuring the dissolved metal concentration of the dissolved metal concentration in the etching solution.

According to the method for measuring the dissolved metal concentration of the present invention, the same effects as those of the above-described dissolved metal concentration measuring device can be obtained.

According to the etching liquid management device, the dissolved metal concentration measuring device, and the dissolved metal concentration measuring method of the present invention, since the acid concentration, the oxidizing agent concentration, and the dissolved metal concentration of the etching liquid can be continuously measured in a timely manner, it is possible to frequently and accurately Maintain management at the specified concentration value. Therefore, the liquid properties of the etching solution are fixed, and the liquid life can be increased.

Further, since the concentration of the dissolved metal in the etching liquid is controlled by recovering and removing the dissolved metal in the etching liquid, it is not necessary to supply a replenishing liquid for lowering the dissolved metal concentration. Therefore, the unnecessary increase of the etching liquid can be suppressed, the replenishing amount of the replenishing liquid can be greatly reduced, and the amount of the waste liquid can be reduced to the limit, so that the waste liquid processing cost can be reduced. In addition, it is possible to carry out the recovery at the time of production of the dissolved metal wire.

Further, by constantly maintaining the etching liquid at the most suitable liquid property, the downtime of the production apparatus can be reduced, and productivity can be improved. Further, it is possible to prevent the occurrence of etching residue due to precipitation of dissolved metal due to the progress of the etching process, and it is possible to improve the yield of the product.

1‧‧‧etching tank

2‧‧‧Overflow trough

3‧‧‧Level gauge

4‧‧‧ etching chamber cover

5‧‧‧Roller conveyor

6‧‧‧Substrate

7‧‧‧etching liquid sprayer

8‧‧‧ Liquid pump

9‧‧‧Filter

10,12‧‧‧Circulation pipeline

11, 15‧ ‧ Circulating pump

13‧‧‧Dissolved metal recovery and removal device

14a‧‧‧liquid supply piping

14b‧‧‧Reflow piping

17‧‧‧1st physical property measuring device

18‧‧‧Second physical property measuring device

19‧‧‧3rd physical property measuring device

20‧‧‧Liquid discharge pump

21‧‧‧etching stock solution supply tank

22‧‧‧ etching new liquid supply tank

23‧‧‧ Acid solution supply tank

24‧‧‧Pipe

25, 26, 27, 161‧‧‧ flow control valve

28‧‧‧Flow regulating valve (pure water supply valve)

29‧‧‧Confluence pipeline

30‧‧‧ computer

31‧‧‧Sampling piping

32‧‧‧Sampling pump

33‧‧‧Reflow piping

35‧‧‧Crystal tube (outer casing)

36‧‧‧Transport screw

36a‧‧‧Rotary axis

36b‧‧‧Spiral blades

37‧‧‧Motor

38‧‧‧ crystallization recovery container

39‧‧‧Continuous piping

39a‧‧‧ Opening

41‧‧‧Pipe

41a‧‧‧ openings

42‧‧‧Heat exchange unit

44, 45‧‧‧Pipe connection

46, 47‧‧ vents

100, 110‧‧ ‧ etching treatment mechanism

113‧‧‧Electrolytic device

135‧‧‧Recycling tank

144, 145‧‧‧Pipe connection

151‧‧‧Anode

152‧‧‧ cathode

153‧‧‧Power supply

154‧‧‧Scraper

155‧‧‧Metal

160‧‧‧Oxidant stock solution supply tank

161‧‧‧Oxidant stock supply valve

A‧‧‧ etching processing department

B‧‧‧ Etching liquid circulation department

C‧‧‧Dissolved Metal Recovery and Removal Department

D‧‧‧Replenishment Supply Department

E‧‧‧Determination Department

Θ‧‧‧ angle

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

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

Fig. 3 is a graph showing the relationship between the dissolved metal concentration of the etching solution and the density.

Fig. 4 is a schematic view showing a crystallization apparatus according to an embodiment of the dissolved metal recovery and removal apparatus.

Fig. 5 is a schematic view showing an electrolysis apparatus of another embodiment of the dissolved metal recovery and removal apparatus.

Fig. 6 is a system diagram of an etching treatment mechanism including an etching liquid management device according to a second embodiment of the present invention.

[Formation of the Invention]

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

[First Embodiment]

Fig. 1 is a system diagram of an etching processing mechanism 100 including an etching liquid management device according to a first embodiment of the present invention.

The etching liquid management device of the present embodiment is mainly applied to an etching process in which a metal film or a metal compound film is etched, and the etching liquid is an acid-containing solution, and management of an acid concentration and a dissolved metal concentration of the etching liquid is important. . The system diagram of Fig. 1 includes an etching treatment unit A including an etching treatment tank 1 that stores an etching liquid at a concentration of a predetermined concentration, which is connected to the etching liquid management device of the present invention, and is stored in the etching treatment. The etching liquid circulation portion B in which the etching liquid in the tank 1 is circulated/stirred, and the dissolved metal recovery removing portion C for recovering and removing the metal component dissolved in the etching liquid from the etching liquid, and the replenishing liquid supply tank 21 containing the various replenishing liquids. ~23 and the replenishing liquid supply unit D of the flow rate adjusting valves 25 to 28 attached to the control switch of the replenishing liquid supply line, and the measuring unit E for measuring the physical properties of the etching liquid in relation to the acid concentration or the dissolved metal concentration of the etching liquid, A computer 30 or the like that performs various calculations or controls. Further, the etching liquid management device of the present invention comprises the dissolved metal recovery and removal unit C, the flow rate adjusting valves 25 to 28 in the replenishing liquid supply unit D, the measuring unit E, and the computer 30.

<etching processing unit A>

The etching treatment portion A is for ejecting an etching liquid onto the surface of the substrate to be transported, thereby etching the surface of the substrate.

As shown in Fig. 1, the etching processing unit A includes an etching treatment tank 1 in which an etching liquid is stored, an overflow tank 2 for receiving an etching liquid overflowed from the etching processing tank 1, and an etching in the etching processing tank 1. The liquid level gauge 3 of the liquid level, the etching chamber cover 4, the roll conveyor 5 for transporting the substrate 6 disposed above the etching processing tank 1, the etching liquid sprayer 7, and the like.

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

When the liquid feeding pump 8 is operated, the etching liquid stored in the etching 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 via the roller conveyor 5 is etched. Further, the surface of the substrate 6 is covered with a metal film or a metal compound film and a resist film.

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

<etching liquid circulation part B>

The etching liquid circulation portion B is mainly used to circulate and stir the etching liquid stored in the etching treatment tank 1.

The bottom of the etching treatment tank 1 is connected to the side portion of the etching treatment tank 1 by a circulation line 12 in which the circulation pump 11 is provided on the way. When the circulation pump 11 is operated, the etching liquid stored in the etching treatment tank 1 is circulated through the circulation line 12. The etching liquid is returned from the side of the etching treatment tank 1 to the etching treatment tank 1 via the circulation line 12, and the stored etching liquid is stirred.

Further, when the replenishing liquid flows into the circulation line 12 through the merging line 29, the inflowing replenishing liquid is supplied into the etching treatment tank 1 while being mixed with the etching liquid circulating in the circulation line 12.

<Soluble metal recovery removal unit C>

The dissolved metal recovery and removal unit C of the dissolved metal recovery and removal means is for recovering the metal component eluted from the film to be etched by the etching process into the etching liquid, and is separated from the etching liquid. The concentration of dissolved metal in the etching solution can be lowered by recovering/removing the metal component from the etching solution.

The dissolved metal recovery and removal unit C includes a dissolved metal recovery and removal device 13, a liquid supply pipe 14a that supplies the etching liquid stored in the etching treatment tank 1 to the dissolved metal recovery and removal device 13, and an etching liquid that is provided in the liquid supply pipe 14a. The circulation pump 15 is for returning the etching liquid processed by the dissolved metal recovery and removal device 13 to the reflux pipe 14b of the etching treatment tank 1. The etching treatment tank 1 and the dissolved metal recovery device 13 are connected by a liquid supply pipe 14a and a return pipe 14b. The dissolved metal recovery and removal device 13 is connected to the computer 30, and is appropriately operated or stopped in accordance with an instruction from the computer 30.

When the dissolved metal recovery device 13 is in operation, the circulation pump 15 is operated, and the etching liquid in the etching treatment tank 1 is sent to the dissolved metal recovery device 13 via the liquid supply pipe 14a. Transfer to dissolved metal recovery unit The etching liquid of 13 is obtained by dissolving and removing the metal component dissolved in the etching liquid by the dissolved metal recovery device 13, thereby reducing the dissolved metal concentration of the etching liquid. The dissolved metal recovery device 13 is operated by the computer 30 so that the dissolved metal concentration in the etching liquid becomes equal to or less than the threshold value of the concentration of the designated management value, based on the measured value of the dissolved metal concentration of the etching liquid. Further, in the operation control of the dissolved metal recovery and removal device 13, a controller such as a sequencer may be used instead of the computer 30.

<Replenishing liquid supply unit D>

The replenishing liquid supply unit D is for supplying the replenishing liquid to the etching treatment tank 1 . As the replenishing liquid, there are an etching stock solution, an etching new liquid, an acid stock solution, pure water, and an etching regeneration liquid. Since these are not necessarily completely required, the most suitable replenishing liquid and supply device can be selected according to the composition of the etching liquid, the degree of concentration change, equipment conditions, operating conditions, and the state of acquisition of the replenishing liquid.

The replenishing liquid supply unit D includes an etching stock solution supply tank 21 for storing each replenishing liquid, an etching new liquid supply tank 22, an acid raw material supply tank 23, and an existing piping for supplying pure water. Here, the supply tanks 21 to 23 are only an example, and the number of the supply tanks or the type of the replenishing liquid of the contents thereof may be appropriately selected in accordance with the conditions of the etching liquid.

The liquid supply pipe for supplying the replenishing liquid from each of the supply tanks 21 to 23 and the existing piping for supplying pure water are provided with flow rate adjusting valves 25 to 28 that control the switch via the computer 30, and are collected in the confluence before the flow rate adjusting valve. The line 29 is connected to the circulation line 12. Furthermore, in the present embodiment, the computer 30 and the flow rate adjusting valves 25 to 28 correspond to the replenishing liquid delivery control means. Each of the supply tanks 21 to 23 is connected to a pipe 24 for supplying N ₂ gas, and each of the supply grooves 21 to 23 is pressurized by the N ₂ gas supplied from the pipe 24 . Therefore, if at least one of the flow regulating valves 25 to 28 is opened by the control of the computer 30, the replenishing liquid corresponding to the controlled flow regulating valve passes through the liquid supply line, the confluent line 29, and the circulation line. 12 is pressurized and transported into the etching treatment tank 1. Further, in the switching control of the flow rate adjusting valves 25 to 28, a controller such as a sequencer may be used instead of the computer 30.

For example, when the flow rate adjusting valve 25 (etching stock solution valve) is opened by the control of the computer 30, the etching stock solution stored in the etching stock solution supply tank 21 is passed through the liquid supply line, the joining line 29, and the circulation line 12. It is pressurized and sent to the etching treatment tank 1. Similarly, when the flow rate adjustment valve 28 (pure water supply valve) is opened by the control of the computer 30, the pure water from the existing piping is supplied through the liquid supply line, the junction line 29, and the circulation line 12. It is supplied into the etching treatment tank 1.

Since each flow regulating valve is flow-regulated to a specified amount of liquid flowable when it is opened, the time for opening each flow regulating valve is controlled by the computer 30, and only the necessary amount of replenishing liquid is replenished.

In the first drawing, each of the replenishing liquids flows into the circulation line 12 through the respective liquid supply piping and the joining line 29, and is supplied into the etching treatment tank 1 while being mixed with the etching liquid circulating in the circulation line 12. The replenishing method of the replenishing liquid is not limited thereto, and the replenishing liquid may be replenished by directly connecting each of the liquid feeding pipes to the circulation line 12 or the etching treatment tank 1 without passing through the joining line 29.

Further, a liquid discharge pump 20 for discharging the etching liquid stored in the etching treatment tank 1 is provided. This is used when the initial cleaning or liquid exchange in the etching treatment tank 1 is used.

In the replenishing liquid supply unit D, the replenishing liquid is replenished based on the acid concentration of the etching liquid obtained from the physical property value measured by the first physical property value measuring device (the first physical property value measuring means) 17 of the measuring unit E described below. The computer 30 compares the value of the acid concentration of the obtained etching liquid with the value of the acid concentration to be managed, and if the acid concentration is insufficient, the acid concentration is increased, and if the acid concentration is excessive, the acid concentration is lowered to supply etching. At least one of the stock solution, the etching fresh liquid, the etching regeneration liquid, the acid stock solution, and the water is used as a replenishing liquid to control the acid concentration to a substantially constant value within the controlled concentration range. In addition, the "replenishment liquid" in the present invention is a liquid used for adjusting the components of the etching liquid, and is a general term for liquids such as etching stock solution, etching new liquid, etching regeneration liquid, acid stock solution, and water. The replenishing liquid system may mix a plurality of liquids before replenishing, or may separately replenish a plurality of liquids separately.

Further, the control of the acid concentration of the etching liquid is not limited to the control of comparing the acid concentration with the management value, and the acid obtained may be used based on the acid concentration value of the etching liquid frequently monitored by the first physical property measuring device 17. The integral or differential value of the concentration over time, or may be controlled by appropriate combination. By enabling the control device thus controlled to operate in conjunction with the first physical property value measuring device 17 and the replenishing liquid transport control means, the acid concentration of the etching liquid can be controlled within a predetermined range in accordance with the acid concentration of the etching liquid.

<Measurement section E>

The measuring unit E is for measuring the acid concentration and the dissolved metal concentration of the sampled etching liquid.

In the measuring unit E, the sampling pump 32 for sampling the etching liquid from the circulation line 10 is connected to the sampling pipe 31, and includes a first physical property value for measuring the etching liquid in relation to the acid concentration of the sampled etching liquid. The first physical property measuring device 17 and the second physical property measuring device (the second physical property measuring device) 18 for measuring the second physical property value of the etching liquid in relation to the dissolved metal concentration of the etching liquid, and the sampled etching liquid Return to the return pipe 33. Further, the sampling pipe 31 and the return pipe 33 may be directly connected to the etching treatment tank 1.

The first physical property value measuring device 17 measures the first physical property value related to the acid concentration in the etching liquid. When the correlation between the acid concentration of the etching liquid obtained in advance and the first physical property value is used, the acid concentration of the etching liquid can be obtained from the measured first physical property value. Further, the second physical property measuring device 18 measures the second physical property value related to the dissolved metal concentration in the etching liquid. When the correlation between the dissolved metal concentration of the etching liquid obtained in advance and the second physical property value is used, the dissolved metal concentration of the etching liquid can be obtained from the measured second physical property value.

The first physical property value measuring device 17 and the second physical property value measuring device 18 are connected to the computer 30, and transmit measurement results and the like to each other.

The correlation between the acid concentration of the etching liquid and the physical property value measured by the first physical property measuring device 17 is as long as the acid concentration of the etching liquid and the physical property value measured by the first physical property measuring device 17 are in a single correspondence relationship. Yes, preferably in polynomial, exponential function, logarithm A simple function such as a function can approximate the relationship, and is preferably a linear relationship.

In general, since the physical property value of the etching liquid changes continuously and smoothly as the acid concentration changes, the first physical property measured by the first physical property measuring device 17 as the acid concentration of the etching liquid shows a gradual change with time. The value also shows a continuous, gradual change over time. Therefore, in the acid concentration range including the management range of the acid concentration of the etching liquid, the correlation relationship between the first physical property value and the acid concentration of the etching liquid can be obtained as described above. Further, when this correlation is used, the acid concentration of the etching liquid can be obtained from the physical property value of the etching liquid measured by the first physical property measuring device 17.

In addition, the correlation between the dissolved metal concentration of the etching liquid and the physical property value measured by the second physical property measuring device 18 is as long as the dissolved metal concentration of the etching liquid and the physical property value measured by the second physical property measuring device 18 The relationship may be a single correspondence, and is preferably a relationship represented by a simple function such as a polynomial, an exponential function, or a logarithmic function, and is preferably a linear relationship.

In general, since the physical property value of the etching liquid changes continuously and smoothly with the change in the concentration of the dissolved metal, the dissolved metal concentration of the etching liquid shows a gradual change with time, and is measured by the second physical property measuring device 18. 2 Physical property values also showed continuous gradual changes over time. Therefore, in the range of the dissolved metal concentration of the etching liquid in the range of the dissolved metal concentration including the management range, the correlation between the second physical property value and the dissolved metal concentration of the etching liquid can be obtained as described above. Further, when this correlation is used, the metal concentration of the etching liquid can be obtained from the physical property value of the etching liquid measured by the second physical property measuring device 18.

The computer 30 determines whether or not the dissolved metal recovery and removal device 13 is operated by comparing the dissolved metal concentration value thus obtained and its management value. When the dissolved metal concentration is higher than the threshold of the managed concentration, the dissolved metal in the etching solution is recovered by the dissolved metal recovery and removal device 13 so that the dissolved metal concentration is lower than the threshold of the managed concentration. Further, the operation of the dissolved metal recovery and removal device 13 can be performed by comparing the dissolved metal concentration obtained from the measured second physical property value with the management value of the dissolved metal concentration. The correlation with the measured second physical property value is performed by comparison with the physical property value corresponding to the management value of the dissolved metal concentration.

The value of the dissolved metal concentration is preferably controlled so that the dissolved metal concentration becomes a dissolved metal concentration value below the upper limit of the managed concentration range. Further, the value of the concentration of the dissolved metal is preferably set in advance, but may be appropriately adjusted during the operation of the apparatus.

As the first physical property measuring device 17, a conductivity meter or an ultrasonic concentration meter can be used. The acid concentration of the acid-containing etching liquid, the conductivity value of the etching liquid, or the ultrasonic conduction speed of the etching liquid have a correlation in a specified range including the management range of the acid concentration. Therefore, by measuring the conductivity value or the ultrasonic conduction velocity of the etching liquid, the acid concentration in the etching liquid can be measured with high precision.

As the second physical property measuring device 18, a densitometer or an absorptiometer can be used. The dissolved metal concentration of the etching solution for etching the metal film or the metal compound film, the density of the etching liquid, or the absorbance value of the specific wavelength of the etching liquid have a correlation within a specified range including the management range of the dissolved metal concentration. Therefore, by measuring the density value or the absorbance value of the etching liquid, the dissolved metal concentration in the etching liquid can be measured with high precision.

[Method for determination of acid concentration and dissolved metal concentration]

Next, an example of a method of measuring the acid concentration and the dissolved metal concentration of the etching liquid will be described. In the following description, the oxalic acid is used as the acid portion, the management value of the acid concentration of the etching solution is set to 3.4%, and the dissolved metal in the etching solution is indium. However, the present invention is not limited thereto. It can also be carried out by other materials and other management values.

As the etching liquid, a 3.4% aqueous solution of oxalic acid used for etching a transparent conductive film or an oxide semiconductor film of one of metal oxide films such as ITO, IZO, IGO, or IGZO, and indium as a dissolved metal were used to prepare a simulated sample liquid. The conductivity and density of the simulated sample solution were measured, and the correlation with the concentration of oxalic acid and the concentration of indium was investigated.

The preparation of the sample was carried out by weighing a specified amount of oxalic acid dihydrate and indium oxide, and dissolving in pure water to prepare samples of various concentrations. Table 1 shows the relationship between the oxalic acid concentration (wt%) and the indium concentration (ppm), and the electrical conductivity (mS/cm) and the density (g/cm ³ ). The sample system is prepared with 10 types of A series samples (A-1~A-10), 10 types of B series samples (B-1~B-10), and 14 types of C series samples (C-1~C-14). Conductivity and density. The C series samples are samples that mimic the condition that the oxalic acid concentration is managed at around 3.4%. Further, the oxalic acid concentration and the indium concentration of the sample were calculated from the weighing value of the reagents weighed at the time of sample preparation. Further, the concentration of oxalic acid is converted into the concentration of the anhydrate. The conductivity value of the sample was measured by a conductivity meter and the density was measured by a vibrating densitometer. The temperature at the time of measurement was set to 25 ° C for all sample measurement temperatures.

Figures 2 and 3 show the results of Table 1 as a graph. Fig. 2 is a graph showing the measurement results of the conductivity values of all the samples in the coordinate system in which the horizontal axis represents the oxalic acid concentration (wt%) of the sample and the vertical axis represents the conductivity (mS/cm) of the sample. As is apparent from Fig. 2, the oxalic acid concentration of the aqueous oxalic acid solution in which indium was dissolved was linearly related to the conductivity. Therefore, based on this relationship, it was confirmed that the oxalic acid concentration of the aqueous oxalic acid solution was obtained by detecting the conductivity of the aqueous oxalic acid solution in the range of the oxalic acid concentration obtained by the linear relationship.

Fig. 3 is a graph showing the measurement results of the density of all the samples in the coordinate system in which the horizontal axis represents the indium concentration (ppm) of the sample and the vertical axis represents the density (g/cm ³ ) of the sample. As is apparent from Fig. 3, in the C series samples in which the oxalic acid concentration was managed to a substantially fixed value, the indium concentration and the density were linear. Therefore, based on this relationship, it was confirmed that the concentration of indium dissolved in the aqueous oxalic acid solution was obtained by detecting the density of the aqueous oxalic acid solution when the oxalic acid concentration was managed to be substantially fixed.

As a result, the inventors discovered by experiment that there is a linear relationship between the acid concentration of the etching solution and the conductivity of the etching liquid, and it is found that the etching can be measured by detecting the conductivity of the etching liquid according to the linear relationship. The acid concentration of the liquid.

Further, the inventors have found through experiments that when the acid concentration is managed to be substantially fixed, there is a linear relationship between the dissolved metal concentration of the etching liquid and the density of the etching liquid, and it is found that the relationship is detected by the linear relationship. The density of the etching solution determines the dissolved metal concentration of the etching solution.

The management range of the acid concentration is within ±0.1% of the management target value (3.4% in Table 1), preferably within ±0.05% of the management target value. By setting the acid concentration to a substantially constant value, it is possible to suppress a change in the density value due to the influence of the change in the concentration of the acid, so that the change in the concentration of the dissolved metal can be correlated with the change in the density of the etching solution. Therefore, the concentration of the dissolved metal in the solution can be accurately determined.

Based on such knowledge, in the measuring unit E, by detecting the conductivity of the etching liquid, the acid concentration of the etching liquid can be obtained from the linear relationship between the acid concentration of the etching liquid and the conductivity. Further, by detecting the density of the etching liquid, the dissolved metal concentration of the etching liquid can be obtained from the linear relationship between the dissolved metal concentration and the density of the etching liquid.

Further, the first physical property measuring device 17 is preferably a conductivity meter, but an ultrasonic concentration meter capable of detecting the ultrasonic conduction velocity of the etching liquid may be used. The second physical property measuring device 18 is preferably a densitometer, but an absorptiometer capable of measuring the absorbance of the etching solution at a specific wavelength may be used. The first physical property value measuring device 17 and the second physical property value measuring device 18 have compensating functions for minimizing the measurement error.

In addition, in the first drawing, the first physical property measuring device 17 and the second physical property measuring device 18 are provided separately from the etching processing tank 1, and the etching liquid is sampled through the sampling pipe 31, but the first physical property is obtained. The physical property value detecting probe portion of the value measuring device 17 and the second physical property measuring device 18 is provided in the etching processing tank 1, and the acid concentration and the dissolved metal concentration of the etching liquid can be obtained.

<computer 30>

The computer 30 is electrically connected to the first physical property measuring device 17, the second physical property measuring device 18, the dissolved metal recovery and removal device 13, and the flow rate adjusting valves 25 to 28. In addition to controlling the operation of the connected devices, the computer 30 also acquires measurement data of the acid concentration or the dissolved metal concentration, and transmits and receives information to and from the connected device. In addition, it has various functions such as input and output functions, computing functions, and information memory functions.

In Fig. 1, the computer 30 controls the acid concentration and the dissolved metal concentration in the etching solution. However, a control device capable of controlling the dissolved metal concentration and a control device capable of controlling the acid concentration may be separately provided. From the viewpoint of simplifying the configuration of the device in a space-saving manner, it is preferable to maintain the management acid concentration and the dissolved metal concentration by the integrated control device, but it is more preferable to perform calculation operations for various calculations. It is completed by a built-in computer that batch-processes the output functions such as the memory function of the measurement data, the input of the set value, and the display of various information such as the measurement data or the calculation result.

[Operation example]

Next, the operation of the etching processing apparatus having the above configuration will be described. In the following, an oxalic acid aqueous solution is used as an example of a transparent conductive film or an oxide semiconductor film which is used for etching a metal oxide film such as ITO, IZO, IGO, or IGZO.

When the liquid feeding pump 8 is operated, the etching liquid stored in the etching 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. By means of roller transport The surface of the substrate 6 transported by the transporter 5 is etched. The etchant is maintained at 35 ° C, for example, to maintain a specified etch rate.

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

For example, if the etching solution maintained at 35 ° C is sprayed, the water preferentially evaporates. Therefore, the oxalic acid concentration of the etching solution rises. Oxalic acid dissolves indium and becomes oxalic acid ions and indium ions, which are consumed. However, since the evaporation amount of water is large, oxalic acid is concentrated, and the etching rate becomes large. Further, by repeating the etching, indium which is eluted from the surface of the substrate by etching is accumulated as a dissolved metal in the etching liquid. When the concentration of the dissolved metal in the etching solution rises, the elution of the metal component from the surface of the substrate is suppressed, so that the etching performance of the etching solution is lowered. As a result, by etching, the etching performance changes due to an increase in the acid concentration of the etching liquid and an increase in the dissolved metal concentration. Therefore, in order to prevent the fluctuation of the etching liquid, the following control is performed.

First, in the measurement unit E, the first physical property value related to the acid concentration of the etching liquid and the second physical property value related to the dissolved metal concentration are measured. The etching liquid which is repeatedly used for the etching treatment is continuously sampled continuously by the sampling pipe 31 and the sampling pump 32, and is supplied to the measuring unit E. As the first physical property measuring device 17, for example, a conductivity meter is used, and as the second physical property measuring device 18, for example, a conductivity meter having a correlation with the acid concentration and a concentration associated with the dissolved metal concentration are detected using a densitometer. Density value.

The first physical property value measuring device 17 and the second physical property value measuring device 18 receive the command from the computer 30, repeatedly detect the conductivity value and the density value of the etching liquid at predetermined intervals, and send the measurement data back to the computer 30. In the computer 30, the correlation between the acid concentration of the etching liquid obtained in advance and the conductivity value (for example, a linear relationship) is retained as a calibration curve, and based on the correlation, the etching liquid is calculated from the detected conductivity value. Oxalic acid concentration. Similarly, in the computer 30, the correlation (for example, a linear relationship) between the dissolved metal concentration and the density value of the etching liquid obtained in advance is retained as a calibration curve, and based on the correlation, the density value is calculated from the detected density value. The dissolved indium concentration of the etching solution.

In the computer 30, the acid concentration and the dissolved metal concentration of the etching liquid thus monitored are compared with their management values, and are maintained at a specified management value.

The control system may employ various control methods such as proportional control, integral control, and differential control, but it is preferable to combine PID (Proportional Integral Derivative) control. When the appropriate PID parameters are set in the computer 30, the acid concentration and the dissolved metal concentration can be controlled so that the management value at the designated management value can be appropriately maintained.

When the acid concentration of the etching liquid is lowered, the flow rate adjusting valve 27 provided in the middle of the piping from the acid raw material supply tank 23 for supplying the acid stock solution is opened in accordance with a control command calculated by the computer 30, and the necessary amount of the acid liquid is supplied. . When the acid concentration of the etching liquid is increased, the flow regulating valve 28 provided in the middle of the existing pure water piping for replenishing pure water is opened in accordance with a control command calculated by the computer 30, and the necessary amount of pure water is replenished. . As a result, the acid concentration of the etching solution is recurring. Monitoring, when deviating from the management value, can be controlled to return to the management value to maintain control at a specified management value.

When the acid concentration of the etching liquid does not decrease, the acid stock supply tank 23 and the flow rate adjusting valve 27 are not required, and when the acid concentration does not rise, the piping for supplying pure water and the flow rate adjusting valve 28 are not required. .

Similarly, when the dissolved metal concentration of the etching liquid rises, the dissolved metal recovery and removal device 13 is operated in accordance with a control command calculated by the computer 30, and the dissolved metal dissolved in the etching liquid is recovered and removed. When the dissolved metal concentration is lowered to a specified value, the dissolved metal recovery and removal device 13 is stopped. As a result, the dissolved metal concentration of the etching liquid is constantly monitored, and when the concentration is higher than the management value, the dissolved metal recovery and removal device 13 is operated to lower the dissolved metal concentration to a predetermined concentration.

By the control of the above computer 30, the acid concentration and the dissolved metal concentration of the etching liquid in the etching treatment tank 1 can be managed within a certain range. For example, even if the acid concentration in the etching increases or the dissolved metal concentration increases due to the etching treatment portion A, the acid concentration and the dissolved metal concentration of the etching liquid in the etching treatment tank 1 can be managed within a certain range.

[dissolved metal recovery and removal device]

Next, a crystallization apparatus according to an embodiment of the dissolved metal recovery and removal apparatus 13 will be described. Fig. 4 is a view showing the crystallization apparatus used as the dissolved metal recovery and removal apparatus 13 of the present invention.

As shown in Fig. 4, the crystallization apparatus is mainly composed of the following: it is inclined at a predetermined installation angle θ with respect to the horizontal direction. The crystallization tube 35, the transport screw 36, the motor 37 that rotates the transport screw 36, the crystallization recovery container 38, and the heat exchange unit 42.

The transport screw 36 is provided in the outer casing 35 along the longitudinal direction, and a spiral spiral blade 36b is attached to the rotary shaft 36a that is rotated via the motor 37. The transport screw 36 is disposed in the crystallization tube 35 so as to be in contact with the inner wall of the crystallization tube 35, and is rotated by a motor 37 in a predetermined direction to scrape the crystal of dissolved metal crystallized in the crystallization tube 35. The precipitate is transported in an etching solution while recovering.

The crystallization tube 35 is inclined at a predetermined angle θ which is appropriately adjusted in accordance with the flow rate or viscosity of the etching liquid, the particle diameter or specific gravity of the crystallization product, the conveying speed of the conveying screw, and the like.

The crystallization tube 35 has an opening 39a that opens downward in the upper portion thereof, and is connected to the crystallization material recovery container 38 via the connection pipe 39. The crystallization product deposited in the crystallization tube 35 is transported to the opening 39a by the transport screw 36, and is collected in the crystallization recovery container 38, and the dissolved metal can be removed from the etching liquid.

The crystallization tube 35 has an opening portion 41a that opens upward in the lower portion thereof, and a pipe 41 that is opened upward is attached. In the crystallization tube 35, the pipe connection portion 44 provided on the outer circumferential surface of the crystallization tube 35 and the pipe connection portion 45 attached to the upward pipe 41 are connected to the liquid supply pipe 14a or the return pipe 14b, and can be subjected to etching treatment. The etching solution of the tank 1 is circulated. Whether or not the pipe connecting portions 44 and 45 are connected to any of the liquid supply pipe 14a or the return pipe 14b is not particularly limited.

Moreover, the position of the opening 39a of the connecting pipe 39 connected to the crystallization tube 35 is higher than the position of the pipe connecting portions 44, 45. The etching liquid in the crystallization tube 35 can be prevented from flowing into the crystallization recovery container 38. The upper portion of the pipe 41 and the upper portion of the crystallization tube 35 are provided with vents 46 and 47 which can release the pressure in the pipe 41 and the inside of the crystallization tube 35 which are opened upward. By the vents 46 and 47, since the pressure in the pipe 41 and the nucleating pipe 35 which are opened upward can be made atmospheric pressure, the liquid level in the pipe 41 and the crystallization pipe 35 which are opened upward can be made the same height. The etching liquid in the crystallization tube 35 can be prevented from flowing into the crystallization recovery container 38.

On the outer side of the crystallization tube 35, a heat exchange unit 42 for cooling the etching liquid in the crystallization tube 35 is attached. The heat exchange unit 42 is not shown in detail, but includes, for example, a thermal module formed of a Peltier element or the like, and a heat exchange sleeve for extensive heat transfer on the outer surface of the crystallization tube 35, and a hot mold. The system is cooled by cooling water for heat removal. In order to further insulate the heat source from the external heat source, the crystallization tube 35 is preferably covered with a heat insulating material (not shown).

Further, the motor 37 and the heat exchange unit 42 are connected to the computer 30, and are respectively driven in accordance with a control command from the computer 30.

As shown in Fig. 4, the crystallization apparatus is preferably a screw conveyor type crystallization apparatus. As shown in Fig. 4, by using a crystallizer having a screw conveyor that can automatically transport crystals while recovering crystallization in the etching liquid line, it is possible to use crystallization without using conventional crystallization. The sedimentation of the material separates and recovers the large crystallization column which can be automatically recovered and transported in the etchant line by the screw conveyor and discharges the crystallization.

<Operation example>

Next, an operation example of the crystallization apparatus will be described.

The second physical property value related to the dissolved metal concentration of the etching liquid measured by the second physical property measuring device 18 is connected to the computer 30 when the computer 30 issues a control command to lower the dissolved metal concentration to a predetermined management value. The motor 37 of the analyzer and the heat exchange unit 42 start to drive. Further, the circulation pump 15 is operated, and the etching liquid is sent from the etching treatment tank 1 to the crystallization tube 35.

When the heat exchange unit 42 is operated, heat is absorbed by the heat module via the heat exchange sleeve covering the crystallization tube 35, and the crystallization tube 35 and the internal etching liquid are cooled. The heat collected in the thermal module is discharged to the outside of the system by cooling the cooling water of the thermal module.

The dissolved metal in the etching solution, for example, dissolved indium in an aqueous solution of oxalic acid, is reduced in temperature, so that the solubility is reduced, so that crystals of indium oxalate are crystallized by cooling. In the oxalic acid aqueous solution cooled by the heat exchange unit 42, a seed crystal of indium oxalate is produced, and the dissolved indium is adhered thereto to grow, and if it is a predetermined size or more, it is in the crystallization tube 35 even when flowing. A precipitate of indium oxalate crystals is formed.

As a result, the crystallization product which has settled to the lower portion of the crystallization tube 35 is automatically scraped up in the crystallization tube 35 by the transfer screw 36 rotated by the motor 37, and is recovered while passing through the upper portion. The opening is sent to the crystallization recovery container 38 for removal.

Inside the crystallization tube 35, the crystallization material recovered by the transport screw 36 in the etching liquid is directly dropped into the crystallization recovery container 38 from the opening portion of the upper portion of the crystallization tube 35.

The temperature cooled by the heat exchange unit 42 is determined according to the type of the etching liquid, the temperature dependence of the solubility of the dissolved metal, or the management value of the dissolved metal concentration. When crystals of indium oxalate are crystallized in an aqueous oxalic acid solution, for example, it is preferably cooled to about 20 °C.

The etching liquid in which the dissolved metal is precipitated in the crystallization tube 35 and the dissolved metal concentration is lowered is circulated to the etching treatment tank 1 through the reflux pipe 14b. The dissolved metal concentration of the etching liquid in the etching treatment tank 1 can be lowered by returning the etching liquid having a reduced dissolved metal concentration.

The above transportation method is an explanation of the operation example of the screw conveyor type crystallization apparatus.

Next, an example of a method of performing crystallization by a screw conveyor type crystallization apparatus will be described by experiments. The inventors discovered by experiment that if the flow rate or viscosity of the etching liquid, the rotation speed or the conveying speed of the conveying screw, the particle size or specific gravity of the crystallization product, etc., the spiral conveyor type crystal is inclined at a predetermined angle. In the deposition apparatus, the crystallization product can be crystallized in the etching liquid in the crystallization tube 35, and the crystallization product can be recovered in the etching liquid, and can be continuously and automatically transported, and collected and removed from the etching liquid. The invention of the screw conveyor type crystallization apparatus included in the present embodiment is completed based on the knowledge of the inventors of the present invention.

In order to simulate the crystallization of indium oxalate in the aqueous oxalic acid solution, the present inventors prepared a test liquid in which fine particles were dispersed in water, and made the inclination angle (set angle) in the horizontal direction with respect to the crystal deposition tube 35 into various types. At the same time, it is confirmed whether the dispersed fine particles can be recovered and transported while transporting the liquid to the screw conveyor type crystallization apparatus tester and changing the rotational speed of the transport screw 36.

The flow rate of the test liquid is 33 (mL/min), and the fine particles having a particle diameter of 800 μm or less are used. The set angle θ of the crystallization tube 35 is in the range of 35 to 55°, and the rotation speed of the transport screw 36 is 0.5 to 5.0 (rpm). The range is tested while performing various changes.

Below, the results are shown in Table 2. The results of the experiment are those in which fine particles having a particle diameter of about 40 μm or more among the fine particles dispersed in the test liquid.

The inventors of the present invention have found that when the arranging angle of the crystallization tube is 50° or less, the rotation speed of the conveying screw is partially removed by 0.5 (rpm), and the crystallization of the specified particle size can be The recovered transport is removed from the etching solution.

In addition, this experiment is carried out using the test liquid under specific conditions, and the conditions such as the installation angle of the crystallization tube and the rotation speed of the transport screw are not limited by the experiment, and can be changed according to the conditions of the etching liquid.

According to the screw conveyor type crystallization apparatus of the present embodiment, it is not necessary to use a complicated crystallization column or a solid-liquid separation device attached thereto, which is often used in the crystallization technique, to realize space-saving crystallization and The crystallization of the crystallization is removed.

Further, since the screw conveyor type crystallization apparatus is controlled by the computer 30 in accordance with the dissolved metal concentration of the etching liquid, the dissolved metal accumulated in the etching liquid can be automatically and continuously crystallized and recovered, and can be removed or not. The etching liquid is often and appropriately managed in such a manner that the specified management value of the metal concentration is dissolved.

As another experimental example, an experiment was carried out using an aqueous solution of potassium chloride. The experimental conditions were carried out by changing the crystallizer installation angle (the installation angle of the crystallization tube) and the screw rotation speed using the conditions shown in Table 3 as a reference. The potassium chloride solution was cooled by a circulating crystallization apparatus, and circulated by the concentration of the potassium chloride solution described in Table 3 and the set temperature of the heat module, and crystallization was confirmed. Table 4 shows the results of changing the crystallizer setting angle, and Table 5 shows the results of changing the screw rotation speed. Further, in Table 4, the water content at a crystallizer installation angle of 55° and the water content at a rotation speed of 0.5 rpm in Table 5 were not able to be measured due to insufficient sample amount (*1).

According to Table 4, the smaller the crystallizer setting angle, the more crystals can be recovered. It is considered that this tendency is because the tendency of the crystal to slide down to the liquid side is weak, so that the screw can easily transport the crystal to the chute. Moreover, when viewing the water content of the crystal, from the data of the installation angle of 35 to 45°, as the installation angle becomes larger, the water content tends to be smaller, but since the water content becomes larger at 50°, From the viewpoint of water, it is judged that 45° is the most appropriate setting angle.

Further, according to Table 5, the larger the rotational speed of the screw, the more the amount of crystal recovered, and the higher the rotational speed of the crystal water, the smaller the water content.

(Other embodiments of the dissolved metal recovery and removal device)

As the dissolved metal recovery and removal device 13, an electrolysis device 113 shown in Fig. 5 can also be used. The electrolysis apparatus is composed of a recovery tank 135, an anode 151, a cathode 152, a power source 153 that supplies a current to the anode 151 and the cathode 152, and an automatic metal to be deposited on the electrode. The removed scraper 154 is recovered. Pipe connection portions 144 and 145 are provided on the side of the recovery tank 135. The pipe connecting portions 144 and 145 are connected to the liquid feeding pipe 14a and the return pipe 14b, and circulate the etching liquid from the etching processing tank 1.

By flowing a current from the power source 153, anions in the etching liquid are accumulated on the anode 151 to emit electrons (oxidation), and on the cathode 152, cations (indium ions, etc.) are collected to receive electrons (reduction). The cation which receives electrons on the cathode 152 becomes a metal and is deposited on the cathode, and the metal dissolved in the etching liquid can be removed.

The cathode 152 which is subjected to electrolytic treatment at a predetermined time is automatically lifted from the recovery tank (electrolysis treatment tank) 135 by an automatic transfer device (not shown), and the scraper disposed separately from the recovery tank 135 is inserted once the electrolysis treatment is stopped. 154. The cathode 152 is configured by moving the recovery tank 135 and the scraper 154 by an automatic transfer device as indicated by an arrow in the figure. The scraper 154 is configured to be in close contact with the cathode 152. By inserting the cathode 152 into the scraper 154, the scraper 154 can be scraped off by a predetermined thickness of the cathode 152. The metal can be recovered from the precipitated metal 155. The metal recovered by the scraper 154 is directly discharged. The cathode 152 after the metal deposited on the surface is removed by the scraper 154 is returned to the recovery tank 135 by the automatic transport device, and the power is discharged. Further, in the fifth drawing, the case where the cathode 152 is inserted into the scraper 154 from the upper side is described, but it is not limited thereto, and the cathode 152 is inserted from the lower side of the scraper 154 or the scraper 154 is made lateral. In the case where the cathode 152 is inserted from the lateral direction, the metal deposited on the cathode 152 can be recovered and removed.

The etching liquid after removing the dissolved metal is returned to the etching treatment tank 1 from the return piping 14b connected to the pipe connecting portions 144 and 145. Further, by depositing a metal on the cathode 152, recovery of the metal can be performed.

[Metal film or metal compound film]

The metal film or the metal compound film used in the film to be etched according to the present embodiment is not particularly limited, but a metal alloy film, a metal oxide film, a metal nitride film, a metal carbide film, a metal vulcanization film, or a metal phosphorus can be used. Film or metal boride film. Further, as the metal oxide film, an ITO film, an IZO film, an IGO film or an IGZO film can be used.

[etching solution]

The acid used in the etching solution of the present embodiment is not particularly limited, but preferably contains at least one of hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid, hydrofluoric acid, perchloric acid, and an organic acid. Further, the organic acid is not particularly limited, and is preferably at least one of oxalic acid, acetic acid, citric acid, and malonic acid.

[Second embodiment]

Fig. 6 is a system diagram of an etching processing mechanism 110 including an etching liquid management device according to a second embodiment of the present invention. The etching liquid management device according to the second embodiment is furthermore than the first physical property measuring device 17 and the second physical property measuring device 18, as compared with the measuring unit E of the etching liquid management device according to the first embodiment. The third physical property measuring device (third physical property measuring means) 19 is different from the etching liquid management device of the first embodiment. The third physical property measuring device 19 measures a third physical property value related to the concentration of the oxidizing agent in the etching solution. If utilized The correlation between the oxidant concentration of the etching liquid obtained in advance and the third physical property value allows the oxidant concentration of the etching liquid to be obtained from the measured third physical property value.

The oxidizing agent concentration of the etching liquid is the physical property value of the etching liquid detected by the third physical property measuring device 19 at a predetermined measurement temperature (for example, 25 ° C), similar to the acid concentration and the dissolved metal concentration, based on the physical property value. Calculated by the correlation (for example, a linear relationship) with the oxidant concentration of the etching solution.

As the third physical property measuring device 19, an absorptiometer, an ultrasonic densitometer, a densitometer, or a redox potentiometer can be used. When the absorbance photometer is used as the third physical property determining means 19, if the correlation between the oxidizing agent concentration in the specified concentration range including the management value of the oxidizing agent concentration and the absorbance value of the etching liquid at a specific wavelength is used as the calibration curve, The oxidant concentration was calculated from the detected absorbance value. Similarly, when the ultrasonic concentration meter is used as the third physical property measuring device 19, the correlation between the oxidizing agent concentration obtained in the specified concentration range including the management value of the oxidizing agent concentration and the ultrasonic conduction velocity value of the etching liquid is used as the calibration curve. Then, the oxidant concentration can be calculated from the detected ultrasonic conduction velocity value. Similarly, when the density meter is used as the third physical property measuring device 19, if the correlation between the oxidizing agent concentration obtained in the specified concentration range including the management value of the oxidizing agent concentration and the density value of the etching liquid is used as the calibration curve, it is possible to The detected density value is used to calculate the oxidant concentration. Similarly, when a redox potentiometer is used as the third physical property measuring device 19, the oxidizing agent concentration obtained in the specified concentration range including the management value of the oxidizing agent concentration and the redox voltage of the etching liquid are used. The correlation between the bit values is used as a calibration curve, and the oxidant concentration can be calculated from the detected redox potential value. As the third physical property measuring device 19, it is possible to determine which device to use in accordance with the type of the oxidizing agent to be measured.

As the oxidizing agent, for example, an aqueous solution containing at least one of hydrogen peroxide water, ozone, nitric acid, persulfuric acid, ammonium cerium nitrate, iron chloride, and copper chloride can be used.

In the second embodiment, the computer 30 constantly monitors the oxidant concentration in addition to the acid concentration and the dissolved metal concentration, and controls to set the management value when the oxidant concentration is deviated from the designated management value.

The adjustment of the oxidant concentration can be carried out by the same method as the adjustment of the acid concentration of the first embodiment. In other words, when the oxidant concentration is lowered to a predetermined value, for example, in order to replenish the oxidant stock solution from the oxidant stock solution supply tank 160 as a replenishing liquid, the flow rate adjusting valve provided as the oxidant stock solution supply valve 161 is opened, and the refilling is required. Amount of oxidant stock solution. When the oxidant concentration rises to be higher than the specified management value, for example, in order to replenish pure water, the pure water supply valve 28 is opened to supply the required amount of pure water.

Further, the third physical property measuring device 19 has compensating functions for minimizing the measurement error. Further, the oxidant concentration, the acid concentration, or the dissolved metal concentration are not limited to the measurement order.

[Third embodiment]

In the etching liquid management apparatus according to the third embodiment of the present invention, the first physical property measuring device 17 of the etching liquid management device according to the first embodiment is replaced with a measurement at least in association with the acid concentration of the etching liquid. In the measuring device for the physical property value, the second physical property measuring device 18 is replaced with a measuring device for measuring the physical property value at least related to the dissolved metal concentration of the etching liquid, and has the physical property value of the etching liquid measured therefrom. The variable analysis method (for example, multiple regression analysis method) calculates the calculation function (calculation means) of the acid concentration of the etching liquid and the dissolved metal concentration. The etching processing mechanism including the etching liquid management device according to the third embodiment can be the same as the etching processing mechanism of the first embodiment shown in Fig. 1.

The etching liquid containing a metal component or the like eluted from the film to be etched is usually composed of various components such as an acid component, an oxidizing agent component, and a dissolved metal component. Therefore, in the etching liquid management apparatus according to the first embodiment and the second embodiment, when the concentration of the other component is maintained under the condition of the specified value, the specific component is measured and the concentration is determined. The correlation between the physical property values and the linear relationship may be approximated within a specified management range. Generally, the measured physical property value of the etching liquid is not related to the concentration of the specific component. For example, the conductivity value of the etching solution associated with the acid concentration, even if strongly dependent on the acid concentration, is strictly affected by other electrolyte components, and the density value of the etching solution associated with the dissolved metal concentration is even It is strongly dependent on the dissolved metal concentration and, strictly speaking, is also affected by other ingredients. Therefore, from the viewpoint of more generally and more precisely managing the concentration of the component of the etching liquid, the physical property value of the measured etching liquid is regarded as not only related to the concentration of the specific component detected by the same, but also to other The treatment of the concentration of the ingredients is necessary and indispensable. Accordingly, by using a multivariate analysis method, for example, a multiple regression analysis method, the concentration of each component that affects the composition can be more accurately calculated from the physical property values of the plurality of measured etching liquids.

The etching liquid management apparatus of the present embodiment is mainly applied to the measurement, control, and management of the acid concentration and the dissolved metal concentration of the etching liquid in the etching process, and the calculation method of the acid concentration and the dissolved metal concentration. Multivariate analytical methods (eg, multiple regression analysis) are used. The control of the acid concentration based on the acid concentration of the etchant to be measured, the control of the dissolved metal concentration based on the dissolved metal concentration of the etchant to be measured, and other configurations are omitted as in the first embodiment. Its description.

[Multi-component operation method]

The inventors have learned from experiments that when the metal is dissolved in an aqueous acid solution, the measured values of the conductivity and the density of the aqueous acid solution do not correspond to only one of the acid concentration and the dissolved metal concentration. They are related to each other, so the concentration can be more accurately determined by multiple regression analysis.

Further, the inventors of the present invention conducted research and analysis on the correlation, and found that the linear characteristic regression analysis (MLR-ILS) can be obtained from two kinds of characteristic values (conductivity values and density values of the acid solution in which the metal is dissolved). Multiple Linear Regression-Inverse Least Squares) is used to calculate the component concentration (acid concentration and dissolved metal concentration) of a more accurate etching solution (aqueous solution of a metal-dissolved acid).

Here, the arithmetic expression of the multiple regression analysis is exemplified. 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. C _ij represents the concentration of the component of the jth number present in the solution of the i-th. Here, i=1~m, j=1~n. For m standard solutions, p characteristic values (for example, absorbance or conductivity or density at a certain wavelength) A _ik (k = 1 to p) were measured. The concentration data and the characteristic value data can each be collectively represented in the form of an array (C, A).

The array associated with these arrays is referred to as a correction array, and is represented here by the symbol S (S _kj ; k = 1 to p, j = 1 to n).

C=A. S

From the known C and A (the content of A is not only a measured value of the same nature, but also a measured value of a different property may be mixed. For example, conductivity and density), the S-system correction phase is calculated by array calculation. At this time, it is necessary to p>=n and m>=np. Since each element of S is an unknown number, it is preferably m>np. In this case, the least squares operation is performed as shown below.

S=(A ^T A) ^-1 (A ^T C)

Herein, the superscript T system means a transposed array, and the superscript -1 means the opposite array.

For the sample liquid with unknown concentration, p characteristic values are measured. If they are regarded as Au (Au _k ;k=1~p), multiply them by S to obtain the desired concentration Cu (Cu _j ;j =1~n).

Cu=Au‧S

This is the forecasting phase.

The present inventors used a sample liquid in which an aqueous solution of oxalic acid in which indium has been dissolved as described in Table 1 above, and selected one of a plurality of calibration standard solutions as an unknown sample, and obtained a corrected array from the remaining standard solution to calculate a hypothetical unknown. The concentration of the sample was calculated by the method of the Leave-One-Out method (go to a cross-validation method) in comparison with the known concentration (weight modulation value), and the calculation results are shown in Table 6. Table 6 shows the concentrations of oxalic acid and indium determined from the measured values of conductivity and density.

The correction array at this time is shown in Table 7.

By using the operation of the multiple regression analysis based on the above experiment, the inventors have learned that if the conductivity of the etching solution is within a specified range (for example, 55.00 ± 2.5 (mS/cm)), the standard deviation can be 24 (ppm). The accuracy of the degree is calculated as the dissolved indium concentration, and the oxalic acid concentration is calculated with an accuracy of the standard deviation of 32 (ppm).

Further, in the present embodiment, the multi-component calculation method is realized by the arithmetic function of the computer 30. In other words, when the computer 30 is previously input with a multivariate analysis method (for example, a multiple regression analysis method), the computer 30 is configured to measure the first physical property of the first physical property value related to at least the acid concentration of the etching liquid. The value measuring device 17 and the second physical property measuring device 18 that measures at least the second physical property value related to the dissolved metal concentration of the etching liquid are connected, so that two physical property values different from the etching liquid measured by the above can be obtained ( For example, conductivity and density, the acid concentration and dissolved metal concentration of the etching solution are calculated by an arithmetic program.

The process of calculating the acid concentration and the dissolved metal concentration of the etching liquid in the present embodiment is the same as that of the first embodiment, and thus the description thereof will be omitted.

Further, in the samples shown in Table 6, other physical property values were used, and the MLR-ILS calculation was also performed by the Leave-One-Out method. As the physical properties, the ultrasonic wave propagation speed (FUD-1: manufactured by Fuji Industrial Co., Ltd.) and the relative refractive index (RI-201H: manufactured by Shodex Co., Ltd.) were measured. In addition, the conductivity (CD-5) and the density (DA-5) were measured by using a device in which the company has reorganized the existing measuring device, and separately from Table 1. The density was further measured using a highly accurate measuring device (DMA-5000: manufactured by Anton Paar Co., Ltd.). The measurement results are shown in Table 8.

Secondly, using these measured values, one of the plurality of calibration standard solutions is selected as an unknown sample, and the calibration array is obtained from the remaining standard solution, and the concentration of the hypothetical unknown sample is calculated by using the known concentration (weight). Modulation value) The comparison method of the Leave-One-Out method performs the MLR-ILS calculation. As an example of the calculation results, Table 9 shows the concentrations of oxalic acid and indium obtained from the measured values of conductivity and density, and Table 10 shows the concentrations of oxalic acid and indium obtained from the conductivity and the ultrasonic propagation velocity. Further, Table 11 shows a correction array when conductivity and density are used, and Table 12 shows a correction array when conductivity and ultrasonic propagation speed are used. Further, in the present embodiment, the physical property value relating to at least the acid concentration of the etching liquid and the physical property value relating to at least the dissolved metal concentration of the etching liquid are used, and the acid concentration and the dissolved metal are calculated by the multivariate analysis method. concentration. The conductivity, density, ultrasonic propagation velocity, and relative refractive index of the measured physical property values are related to both the acid concentration and the dissolved metal concentration. Therefore, it is possible to perform all combinations of physical property values. Multivariate analysis.

According to Tables 11 and 12, in the combination of conductivity and density, the sensitivity of indium to density is very large, and the sensitivity is changed by about 80 ppm at a sensitivity of 0.0001 g/cm ³ , relative to the conductivity and the propagation speed of ultrasonic waves. In the combination, the sensitivity of the concentration to the ultrasonic propagation velocity is relatively small, indicating that the sensitivity is 0.01 m/s, and if the concentration is converted, it is about 3.5 ppm.

Moreover, the combination of the electrical conductivity and the ultrasonic wave propagation speed is relatively small in sensitivity to the electrical conductivity, and it is confirmed that the stability of the fluctuation of the measured value is increased.

Further, Table 13 shows the concentrations of oxalic acid and indium obtained from the electrical conductivity and the ultrasonic propagation velocity (ideal value). In addition, the so-called ultrasonic propagation velocity (ideal value) predicts the value of the ultrasonic propagation velocity from the component concentration at the time of preparation of the sample, and uses the concentration of each component as the explanatory variable to the ultrasonic propagation velocity (FUD-1). The measured value is used as the target variable, and multiple regression analysis is performed to predict the value from the result.

Further, Table 14 shows the standard deviation (ppm) of the predicted value of the oxalic acid of the combination of the respective measurement items and the standard deviation (ppm) of the indium predicted value.

The "composite deviation index" in Table 14 is an index indicating the prediction accuracy of the combination of each measurement item, and can be obtained by the following equation. The standard deviation of the respective predicted values is divided by the standard deviation of the actual concentrations, and they are totaled. A smaller value than the composite deviation indicator indicates a comprehensive predictor.

As shown in Tables 9, 10 and 14, the prediction accuracy of the concentration of oxalic acid and indium was calculated from the measurement results of the conductivity and the density, and as a result, the standard deviation of oxalic acid was 0.0029%, and the standard deviation of indium was 39 ppm. Moreover, the prediction accuracy of the concentration of oxalic acid and indium was calculated from the measurement results of the electrical conductivity and the ultrasonic propagation velocity, and the standard deviation of oxalic acid was 0.0030%, and the standard deviation of indium was 69 ppm, which did not change with the prediction accuracy of oxalic acid, but indium The prediction accuracy is nearly doubled, but there is no special problem. In the combination shown in Table 14, any combination can be measured with high precision. In particular, it is considered preferable to combine the conductivity and the ultrasonic propagation speed to obtain a minimum composite deviation index.

[Fourth embodiment]

In the etching liquid management device according to the fourth embodiment of the present invention, the first physical property measuring device 17 of the etching liquid management device according to the second embodiment is replaced with a measuring device for measuring a physical property value related to at least the acid concentration of the etching liquid. The second physical property measuring device 18 is replaced with a measuring device that measures a physical property value related to at least the dissolved metal concentration of the etching liquid, and the third physical property measuring device 19 is replaced with a measurement that is at least related to the oxidizing agent concentration of the etching solution. The physical property value measuring device has a physical property value of the etching liquid measured from the above, and a calculation function of calculating the acid concentration and the dissolved metal concentration of the etching liquid by a multivariate analysis method (for example, multiple regression analysis). The etching processing mechanism including the etching liquid management device according to the fourth embodiment can be the same as the etching processing mechanism of the second embodiment shown in Fig. 6.

The etching liquid management apparatus of the present embodiment is mainly applied to an acid concentration in which an etching liquid must be more precisely performed in an etching process. For the measurement, control, and management of degrees, dissolved metal concentrations, and oxidant concentrations, multivariate analytical methods (eg, multiple regression analysis) are used in the calculation of acid concentration, dissolved metal concentration, and oxidant concentration.

The multi-component calculation method of the present embodiment is basically the same as adding three measurement components to the multi-component calculation method of the third embodiment, and is essentially the same. In other words, if the calculation program of the multivariate analysis method (for example, multiple regression analysis method) is input in advance in the computer 30, the computer 30 is connected to the first physical property that measures the first physical property value at least related to the acid concentration of the etching liquid. The value measuring device 17 includes a second physical property measuring device 18 that measures a second physical property value related to at least a dissolved metal concentration of the etching liquid, and a third physical property that measures at least a third physical property value related to the oxidizing agent concentration of the etching liquid. Since the value measuring device 19 obtains three different physical property values (for example, conductivity and density and absorbance at a specific wavelength) of the etching liquid measured by the above, the acid concentration and dissolved metal concentration of the etching liquid are calculated by an arithmetic program. And oxidant concentration.

The other configuration is the same as that of the second embodiment, and the description thereof is omitted.

[Solution metal concentration measuring device and method for measuring dissolved metal concentration]

The dissolved metal concentration measuring apparatus and the dissolved metal concentration measuring method for measuring the concentration of the dissolved metal in the etching solution can be used.

The apparatus for measuring the concentration of dissolved metal is used to measure the acid concentration in the etching solution by the first physical property measuring device 17 of the acid concentration measuring means of the etching processing means shown in Fig. 1 (acid concentration measuring step) Step). The acid concentration is measured as described in the first embodiment, and the acid concentration can be measured by measuring the first physical property value related to the acid concentration. Next, the replenishing liquid is supplied by the replenishing liquid delivery control means (replenishing liquid supply part D) based on the measured acid concentration (replenishment liquid delivery control step). The replenishing liquid is replenished so that the acid concentration in the etching liquid becomes within the managed range.

The second physical property value measuring device 18 that measures the physical property value of the physical property value related to the concentration of the dissolved metal in the etching solution is used in the etching solution in which the acid concentration is fixed to the etching solution by the supply of the replenishing liquid. Measurement (physical property value measuring step). The computer 30 stores a correlation (for example, a linear relationship) between the concentration of the dissolved metal in the etching solution and the physical property value measured by the second physical property measuring device 18, and serves as a calibration curve based on the correlation and The physical property value measured by the second physical property measuring device 18 is measured by a computer (dissolved metal concentration measuring means) 30 to measure the concentration of the dissolved metal in the etching liquid (the dissolved metal concentration measuring step).

In addition, the method of measuring the dissolved metal concentration is performed by measuring the acid value in the etching liquid in the managed range, measuring the physical property value related to the dissolved metal concentration, and measuring the dissolved metal concentration. However, it is not limited by this. When the oxidizing agent contains an oxidizing agent, the oxidizing agent concentration measuring means (the oxidizing agent concentration measuring step) for measuring the concentration of the oxidizing agent can also measure the dissolved metal concentration by setting the concentration of the oxidizing agent within the managed range.

1‧‧‧etching tank

2‧‧‧Overflow trough

3‧‧‧Level gauge

4‧‧‧ etching chamber cover

5‧‧‧Roller conveyor

6‧‧‧Substrate

7‧‧‧etching liquid sprayer

8‧‧‧ Liquid pump

9‧‧‧Filter

10,12‧‧‧Circulation pipeline

11, 15‧ ‧ Circulating pump

13‧‧‧Dissolved metal recovery and removal device

14a‧‧‧liquid supply piping

14b‧‧‧Reflow piping

17‧‧‧1st physical property measuring device

18‧‧‧Second physical property measuring device

20‧‧‧Liquid discharge pump

21‧‧‧etching stock solution supply tank

22‧‧‧ etching new liquid supply tank

23‧‧‧ Acid solution supply tank

24‧‧‧Pipe

25, 26, 27‧‧‧ flow control valve

28‧‧‧Flow regulating valve (pure water supply valve)

29‧‧‧Confluence pipeline

30‧‧‧ computer

31‧‧‧Sampling piping

32‧‧‧Sampling pump

33‧‧‧Reflow piping

100‧‧‧etching mechanism

A‧‧‧ etching processing department

B‧‧‧ Etching liquid circulation department

C‧‧‧Dissolved Metal Recovery and Removal Department

D‧‧‧Replenishment Supply Department

E‧‧‧Determination Department

Claims (16)

An etching liquid management apparatus which is an etching liquid management apparatus which manages an etching liquid containing an acid and is repeatedly used for etching a metal film or a metal compound film, and is characterized by comprising: a first physical property measuring means for measuring a first physical property value relating to a concentration of the acid in the etching liquid, and a second physical property measuring means for measuring a physical property value of the etching liquid and the etching film from the metal film a second physical property value related to a concentration of the metal dissolved in the metal compound film; and a replenishing liquid transport control means according to a correlation between the concentration of the acid in the etching solution and the first physical property value, and the first The measurement result of the physical property value measuring means controls the delivery of the replenishing liquid supplied to the etching liquid so that the acid concentration becomes within the controlled concentration range; and the dissolved metal recovery and removal means is dissolved according to the etching liquid a correlation between the concentration of the metal and the second physical property value and a measurement result of the second physical property measuring means, wherein the metal concentration becomes a threshold value of the managed concentration The way, is recovered from the etchant removal of the etching solution of the metal dissolved. An etching liquid management device which is an etchant management device that manages an etching liquid containing an acid and an oxidizing agent and is repeatedly used for etching a metal film or a metal compound film, and is characterized by comprising: a first physical property value measuring means; Measuring a first physical property value related to a concentration of the acid in the etching solution that belongs to a physical property value of the etching solution; The second physical property measuring means is for measuring a second physical property value relating to a concentration of a metal dissolved in the metal film or the metal compound film in the etching liquid, which is a physical property value of the etching liquid; and a third physical property measuring means And determining a third physical property value relating to a concentration of the oxidizing agent in the etching liquid that belongs to the physical property value of the etching liquid; and a replenishing liquid transport controlling means according to the concentration of the acid in the etching liquid and the first The correlation between the physical property values and the measurement result of the first physical property measuring means are such that the acid concentration is within the managed concentration range, and the concentration of the oxidizing agent and the third physical property value in the etching solution The correlation between the correlation and the measurement result of the third physical property measuring means controls the delivery of the replenishing liquid supplied to the etching liquid so that the oxidizing agent concentration is within the controlled concentration range; According to the correlation between the concentration of the metal dissolved in the etching solution and the second physical property value and the measurement result of the second physical property measuring means, the metal concentration is controlled The metal dissolved in the etching solution is recovered from the etching solution in a manner below the threshold of the concentration. An etching liquid management apparatus which is an etching liquid management apparatus which manages an etching liquid containing an acid and is repeatedly used for etching a metal film or a metal compound film, and is characterized by comprising: a first physical property measuring means for measuring a first physical property value relating to at least the physical property value of the etching liquid and a concentration of the acid in the etching solution; a second physical property measuring means for measuring a second physical property value relating to at least a concentration of a metal dissolved in the metal film or the metal compound film in the etching liquid, which is a physical property value of the etching liquid; Calculating the acid in the etching solution by the multivariate analysis method from the first physical property value measured by the first physical property measuring means and the second physical property value measured by the second physical property measuring means a concentration and a concentration of the metal dissolved in the etching solution; and a replenishing liquid delivery control means for controlling supply of the acid concentration in the etching solution calculated by the calculation means to be within a controlled concentration range a method of transporting the replenishing liquid to the etching solution; and a means for removing and dissolving the dissolved metal, wherein the concentration of the metal dissolved in the etching solution calculated by the calculating means is equal to or less than a threshold value of the managed concentration. The etching solution recovers and removes the dissolved metal in the etching solution. An etching liquid management device which is an etchant management device that manages an etching liquid containing an acid and an oxidizing agent and is repeatedly used for etching a metal film or a metal compound film, and is characterized by comprising: a first physical property value measuring means; And measuring a first physical property value relating to at least a concentration of the acid in the etching liquid, and a second physical property measuring means for measuring at least the physical property value of the etching liquid and the etching liquid The concentration of the metal dissolved from the metal film or the metal compound film has a second physical property value; a third physical property measuring means for measuring a third physical property value relating to at least a concentration of the oxidizing agent in the etching liquid, which is a physical property value of the etching liquid; and calculating means for measuring the first physical property value The measured first physical property value, the second physical property value measured by the second physical property value measuring means, and the third physical property value measured by the third physical property value measuring means are calculated by a multivariate analysis method. a concentration of the acid in the etching solution, a concentration of the metal dissolved in the etching solution, and a concentration of the oxidizing agent in the etching solution; and a replenishing liquid delivery control means for performing the etching by the calculation means The concentration of the acid in the liquid is within the range of the controlled concentration, and the replenishing liquid supplied to the etching solution is controlled so that the concentration of the oxidizing agent in the etching liquid calculated by the calculating means is within the controlled concentration range. And a means for removing and dissolving the dissolved metal, wherein the concentration of the metal dissolved in the etching solution calculated by the calculation means is equal to or less than a threshold value of the managed concentration , Is recovered from the etchant removal of the etching solution of the metal dissolved. The etching solution management device according to any one of claims 1 to 4, wherein the first physical property measuring means measures a conductivity value of the etching liquid as a conductivity value of the first physical property value, or a measurement of the etching liquid The ultrasonic conduction velocity is used as the ultrasonic concentration meter of the first physical property value. The etching solution management device according to any one of claims 1 to 4, wherein the second physical property measuring means measures a density value of the etching liquid as a density of the second physical property value, or measures an absorbance value of the etching liquid. An absorptiometer as the second physical property value. The etching liquid management device according to claim 2 or 4, wherein the third physical property measuring means measures the absorbance value of the etching liquid as an absorbance photometer of the third physical property value, and measures the ultrasonic conduction velocity of the etching liquid as the The ultrasonic concentration meter of the third physical property value, the density value of the etching liquid is measured as a density of the third physical property value, or an oxidation-reduction potential meter in which the oxidation-reduction potential of the etching liquid is measured as the third physical property value. The etching solution management device according to any one of claims 1 to 4, wherein the dissolved metal recovery and removal means is a crystallization apparatus or an electrolysis apparatus. The etching solution management device of claim 8, wherein the crystallization device is a screw conveyor type crystallization device. The etching solution management device according to any one of claims 1 to 4, wherein the metal compound film is a metal alloy film, a metal oxide film, a metal nitride film, a metal carbide film, a metal vulcanization film, a metal phosphating film or a metal boron Film. The etching solution management device according to claim 10, wherein the metal oxide film is an ITO film, an IZO film, an IGO film or an IGZO film. The etching solution management apparatus according to any one of claims 1 to 4, wherein the etching liquid contains at least one of hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid, hydrofluoric acid, perchloric acid, and an organic acid as an aqueous solution of the acid . The etching solution management device of claim 12, wherein the organic acid is at least one of oxalic acid, acetic acid, citric acid, and malonic acid. The etching solution management apparatus according to claim 2 or 4, wherein the etching liquid contains at least one of hydrogen peroxide, ozone, nitric acid, persulfuric acid, ammonium cerium nitrate, iron chloride, and copper chloride as an aqueous solution of the oxidizing agent . A dissolved metal concentration measuring apparatus for measuring a concentration of a metal dissolved in an etching liquid containing an acid and repeatedly used in etching of a metal film or a metal compound film, characterized in that it has an acid concentration a measuring means for measuring a concentration of the acid in the etching solution; and a replenishing liquid transport controlling means for controlling the acid concentration in the etching liquid to be within a managed concentration range by the acid concentration measuring means And controlling the supply of the replenishing liquid supplied to the etching liquid; and the physical property value measuring means is for measuring a physical property value related to the concentration of the metal dissolved in the etching liquid which belongs to the physical property value of the etching liquid; and measuring the dissolved metal concentration The method measures the concentration of the metal dissolved in the etching solution based on a correlation between the concentration of the dissolved metal in the etching solution and the physical property value and a measurement result of the physical property measuring means. A method for measuring a dissolved metal concentration, which is a method for measuring a dissolved metal concentration of a concentration of the metal dissolved in an etching solution containing an acid and repeatedly used in etching of a metal film or a metal compound film, characterized by having an acid concentration a measuring step of measuring a concentration of the acid in the etching solution; and a replenishing liquid transport controlling step of the acid concentration in the etching liquid measured by the acid concentration measuring means to be within a managed concentration range , controlling the delivery of the replenishing liquid supplied to the etching solution; a physical property value measuring step of measuring a physical property value relating to a concentration of the metal dissolved in the etching solution belonging to the physical property value of the etching liquid; and a dissolved metal concentration measuring step according to the dissolved in the etching liquid The correlation between the concentration of the metal and the physical property value and the measurement result of the physical property value measuring step determine the concentration of the metal dissolved in the etching solution.