JP2010034593A - Substrate processing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a substrate processing apparatus etc., capable of extending an exchange cycle of a processing liquid, of preventing a substrate processing efficiency from lowering, and of reducing a cost of substrate processing. <P>SOLUTION: A substrate processing apparatus 1 includes: a first processing fluid circulation system 20 for circulating a processing fluid between a tank 11 and a substrate processing mechanism 12; two adsorption towers 32, 33 for adsorbing metal ions which are contained in the processing fluid by processing substrates in the substrate processing mechanism 12; a second processing fluid circulation mechanism 34 which circulates the processing fluid in the tank 11 by supplying it selectively to either of the adsorption towers 32, 33; and a controller 28 which controls the operation of the second fluid circulation mechanism 34 so as to alternately switch the adsorption towers 32, 33 at predetermined time intervals. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a substrate processing apparatus including a processing liquid processing apparatus that removes metal ions, particularly indium ions and tin ions, contained in a processing liquid for substrate processing.

  For example, in the process of manufacturing various substrates such as a semiconductor (silicon) wafer, a liquid crystal glass substrate, a photomask glass substrate, and an optical disk substrate, various processing solutions such as an etching solution, a developing solution, and a cleaning solution are supplied to these substrates. There is a step of processing the substrate.

  Conventionally, for example, an etching apparatus disclosed in Japanese Patent Application Laid-Open No. 2000-96264 is known as a substrate processing apparatus used in such a process. The etching apparatus includes a storage tank that stores an etching solution, a substrate processing mechanism that performs an etching process on the substrate with the etching solution, and supplies the etching solution stored in the storage tank to the substrate processing mechanism. An etchant circulation mechanism that recovers from the substrate processing mechanism and circulates the etchant between the storage tank and the substrate processing mechanism, and detects the concentration of components that contribute to the etching process in the etchant stored in the storage tank. And an etching solution that replenishes the storage tank with a new etching solution and maintains the concentration of the contributing component in the etching solution at a constant concentration when the concentration detected by the concentration sensor deviates from a predetermined reference concentration. A replenishment mechanism.

  The substrate processing mechanism includes a processing chamber having a closed space, a plurality of transport rollers disposed in the processing chamber, horizontally supporting the substrate and transporting in a predetermined direction, and disposed above the transport rollers. It consists of a plurality of nozzle bodies for discharging an etching solution toward the upper surface of the substrate.

  The etchant circulation mechanism includes a supply pipe in which one end side is connected to the storage tank, the other end side is provided in the processing chamber, and each nozzle body is fixed to the other end side, and each nozzle is provided via the supply pipe. A supply pump for supplying an etching solution to the body, a recovery pipe having one end connected to the bottom of the processing chamber and the other end connected to a storage tank.

  According to this etching apparatus, the substrate is transported in a predetermined direction by the transport roller, and the etching liquid stored in the storage tank is supplied to each nozzle body via the supply pipe by the supply pump, and the substrate from each nozzle body. The substrate is discharged onto the upper surface and the substrate is etched by the etching solution.

  Then, the etching solution discharged onto the upper surface of the substrate flows through the collection tube and is collected from the processing chamber into the storage tank. The contribution component concentration in the etching solution stored in the storage tank is detected at any time by a concentration sensor, and if the contribution component concentration detected by the concentration sensor deviates from a predetermined reference concentration, a new solution is added by the etching solution supply mechanism. The etching solution is replenished into the storage tank, and the concentration of the contributing component in the etching solution is maintained at a constant concentration.

JP 2000-96264 A

  By the way, for example, when etching is performed on a metal film such as an indium tin oxide film formed on the upper surface of the substrate, the metal such as indium and tin constituting the metal film is dissolved in the etching solution by the etching. Therefore, in the conventional etching apparatus configured to circulate the etching solution between the storage tank and the substrate processing mechanism, the concentration of the metal contained in the etching solution gradually increases, and this metal concentration is reduced. If it exceeds a certain level, the etching rate is lowered, and there is a disadvantage that an accurate etching shape cannot be obtained.

  For this reason, in the said conventional etching apparatus, since the etching liquid in a storage tank must be replaced | exchanged regularly, since an etching process cannot be performed during replacement | exchange of an etching liquid, substrate processing efficiency falls. In addition, the cost of the etching process increases due to such a decrease in processing efficiency and the cost for replacing the etching solution (the disposal cost of the replaced etching solution and the purchase cost of the etching solution to be replaced).

  The present invention has been made in view of the above circumstances, and can maintain a high processing accuracy and processing efficiency of the substrate, and can increase the life of the processing liquid, thereby increasing the amount of the processing liquid used. It is an object of the present invention to provide a substrate processing apparatus that can reduce substrate processing costs.

To achieve the above object, the present invention provides:
A storage tank for storing a treatment liquid containing oxalic acid;
A processing means that includes a processing chamber and a nozzle body that is disposed in the processing chamber and that discharges the processing liquid, and that processes the substrate on which the indium tin oxide film is formed with the processing liquid discharged from the nozzle body. When,
A first supply pipe for supplying the processing liquid in the storage tank to the nozzle body, a first supply pump provided in the first supply pipe, and a first recovery for connecting the storage tank and the processing chamber. And a processing liquid in the storage tank is supplied to the nozzle body and discharged by the first supply pipe and the first supply pump, and the discharged processing liquid is supplied to the processing chamber by the first recovery pipe. The substrate processing circulation means for recovering in the storage tank and circulating the processing liquid between the storage tank and the processing means,
An adsorption means comprising at least two adsorption towers arranged side by side, each of the adsorption towers filled with a chelating agent that adsorbs indium ions and tin ions in the treatment liquid;
One end is connected to the storage tank, the other end is branched and connected to each adsorption tower, and a second supply pipe for supplying the treatment liquid in the storage tank to each adsorption tower; A second supply pump provided between one end of the supply pipe and the branch part; a first switching valve provided in the second supply pipe for controlling the supply of the processing liquid to each adsorption tower; A second recovery pipe for recovering the processing liquid flowing through each adsorption tower in the storage tank, and selecting one of the adsorption towers by switching the first switching valve In particular, the present invention relates to a substrate processing apparatus comprising a removal processing circulation means for supplying and circulating the processing liquid.

  According to this substrate processing apparatus, the processing liquid stored in the storage tank is supplied to the nozzle body by the first supply pipe and the first supply pump and discharged from the nozzle body, and the substrate is processed by the discharged processing liquid. The The discharged processing liquid is recovered from the processing chamber into the storage tank by the first recovery pipe, and thus the processing liquid is circulated between the storage tank and the processing means. Then, in the circulating processing liquid, the indium tin oxide film on the substrate is dissolved and contains indium ions and tin ions in the processing process in the processing means.

  On the other hand, the processing liquid stored in the storage tank is circulated between the storage tank and any one of the adsorption towers by the second supply pipe, the second supply pump, the first switching valve, and the second recovery pipe, Indium ions and tin ions in the treatment liquid are adsorbed by the chelating agent in the adsorption tower and removed from the treatment liquid.

  For example, the adsorption tower to which the treatment liquid is supplied can be switched by switching the first switching valve as appropriate when it is determined that the indium ions and tin ions adsorbed on the chelating agent have reached a substantially saturated state. The adsorption tower is changed so that the adsorption capacity of the adsorption means is kept constant. When the adsorption tower to which the processing liquid is supplied is switched, the adsorption tower that has stopped supplying the processing liquid is appropriately regenerated with an eluent that elutes indium and tin adsorbed on the chelating agent. Is done.

  Thus, according to the substrate processing apparatus of the present invention, the processing liquid in the storage tank is circulated between one of the storage tank and the adsorption tower, so that the indium ions in the processing liquid are processed while performing the processing. In addition, the adsorption and removal of tin ions can prolong the life of the treatment liquid and lengthen the treatment liquid replacement cycle, and the longer the treatment liquid replacement cycle, Costs required for the processing liquid, such as the disposal cost of the used processing liquid, can be kept low, and the cost for substrate processing using the processing liquid can be reduced.

  Further, if the processing liquid is continuously circulated through the adsorption tower while the substrate is being processed by the processing means, the concentrations of indium ions and tin ions in the processing liquid can always be kept below a certain level. Thereby, it is possible to prevent the occurrence of defective etching or to operate continuously without stopping the processing means, and to improve the yield and the substrate processing efficiency.

  Further, since the treatment liquid in the storage tank is circulated while switching the adsorption tower to which the treatment liquid is supplied by switching the first switching valve, indium ions and ions are removed from the treatment liquid without reducing the adsorption capacity of the adsorption means. Tin ions can be removed and removed efficiently.

  The substrate processing apparatus is provided in an eluent supply pipe for supplying an eluent for eluting indium and tin adsorbed by the chelating agent of each adsorption tower to each adsorption tower, and in the eluent supply pipe. And a second switching valve for controlling the supply of the eluent to each of the adsorption towers, and the elution is selectively performed for any one of the adsorption towers by switching the second switching valve. An eluent supply means for supplying a liquid and an eluent recovery means for recovering the eluent flowing through each adsorption tower, and the supply of the processing liquid is stopped by switching the second switching valve. In addition, the eluent may be supplied to the adsorption tower in which the chelating agent has adsorbed indium and tin.

  In this way, when the adsorption tower to which the processing liquid is supplied is switched by the first switching valve of the removal processing circulation means, the second switching valve of the eluent supply means is appropriately operated and switched, whereby the processing is performed. The eluent is supplied to the adsorption tower where the liquid supply has been stopped. The indium and tin adsorbed by the chelating agent in the adsorption tower are eluted by this eluent, and the eluent containing the eluted indium ions and tin ions is recovered by the eluent recovery means. Thereby, the chelating agent can be regenerated. Further, indium dissolved in the processing liquid is very expensive, and it is convenient if it can be recovered. However, by appropriately recovering indium ions in the eluent recovered as described above, the processing liquid can be recovered. It is also possible to recover expensive metals dissolved in the solution.

  In addition, the substrate processing apparatus is provided in a cleaning liquid supply pipe for supplying a cleaning liquid for cleaning the inside of each adsorption tower to each adsorption tower, and in the cleaning liquid supply pipe, and the cleaning liquid is supplied to each adsorption tower. A third switching valve for controlling supply, and a cleaning liquid supply means for selectively supplying the cleaning liquid to any one of the adsorption towers by switching the third switching valve; and each of the adsorption towers A cleaning liquid discharge pipe for discharging the cleaning liquid flowing through the inside to the outside, and switching the third switching valve to supply the cleaning liquid to the adsorption tower after supplying the eluent. Also good.

  In this way, when the elution of the metal adsorbed on the chelating agent is completed, the cleaning liquid is supplied to the adsorption tower after the eluent is supplied by appropriately switching the third switching valve of the cleaning liquid supply means. . The inside of the adsorption tower is cleaned by this cleaning liquid, and the cleaning liquid is discharged to the outside from the cleaning liquid discharge pipe. If the eluent remains inside the adsorption tower, when the processing liquid in the storage tank is supplied to the adsorption tower, the processing liquid and the elution liquid are mixed, which adversely affects substrate processing using the processing liquid. However, such an inconvenience can be effectively prevented by washing away the eluent remaining in the adsorption tower with the washing liquid.

  The substrate processing apparatus may further include a control unit that switches the first switching valve at a preset time interval. In this case, the first means of the removal processing circulation means is determined by the control means at a predetermined time interval, that is, at a time interval at which it is estimated that indium and tin adsorbed by the chelating agent of the adsorption tower have reached a substantially saturated state. The switching valve is switched, and the adsorption tower to which the processing liquid is supplied is switched. Therefore, even if comprised in this way, since the adsorption | suction capability in an adsorption | suction means is maintained uniformly, the effect similar to the above can be acquired.

  Alternatively, the switching control of the first switching valve may be performed based on the number of substrates processed by the processing means. That is, counting means for counting the number of substrates processed by the processing means and outputting a switching signal when the counted number reaches a preset number; and when the switching signal is received from the counting means And a control means for switching the first switching valve.

  In this case, when the number of substrates processed in the processing means becomes a predetermined number, that is, when the number of indium and tin adsorbed by the chelating agent of the adsorption tower is estimated to have reached a substantially saturated state, The first switching valve is switched, and the adsorption tower to which the processing liquid is supplied is switched. Therefore, even if comprised in this way, since the adsorption | suction capability in the said adsorption | suction means is maintained constant, the effect similar to the above can be acquired.

  Further, the substrate processing apparatus includes a concentration detection unit that detects an ion concentration of at least one of indium ions and tin ions in the processing liquid stored in the storage tank, and an ion concentration detected by the concentration detection unit in advance. Control means for switching the first switching valve when the reference value becomes higher than a set reference value may be provided.

  In this case, the switching control of the first switching valve of the removal processing circulation means by the control means is executed as follows. That is, indium and tin adsorbed by the chelating agent in the adsorption tower reach a substantially saturated state, the adsorption capacity decreases, and the concentration of indium ions and tin ions in the treatment liquid in the storage tank rises and is detected by the concentration detection means. When the ion concentration to be applied becomes higher than a predetermined reference value, the first switching valve is switched, and the adsorption tower to which the processing liquid is supplied is changed to another adsorption tower.

  Therefore, even if comprised in this way, since the adsorption | suction capability in an adsorption | suction means is maintained uniformly, the effect similar to the above can be acquired.

  Further, the substrate processing apparatus includes a contribution component concentration detection unit that detects a concentration of a component that contributes to the substrate processing in the processing liquid stored in the storage tank, and a contribution detected by the contribution component concentration detection unit. Concentration adjusting means for adjusting the concentration of the contributing component in the processing liquid stored in the storage tank based on the component concentration and maintaining the concentration within a preset range may be provided.

  In this way, since the contribution component concentration in the treatment liquid stored in the storage tank can be maintained within a predetermined range, the contribution component concentration of the treatment liquid in the storage tank is reduced by the substrate processing in the processing means. It is possible to prevent the disadvantage that the predetermined processing capability cannot be obtained due to fluctuations, and to maintain the substrate processing capability with the processing liquid in an optimum state.

  Examples of the substrate include, but are not limited to, a semiconductor (silicon) wafer, a liquid crystal glass substrate, a photomask glass substrate, and an optical disk substrate. Examples of the processing solution include, but are not limited to, an etching solution, a developing solution, and a cleaning solution.

  The chelating agent is generally a generic term for organic aminocarboxylates, and has the property of adsorbing metal ions and eluting the adsorbed metal by a specific solution. It is. Specifically, EDTA (ethylenediaminetetraacetic acid), NTA (nitrilotriacetic acid), DTPA (diethylenetriaminepentaacetic acid), GLDA (L-glutamic acid diacetic acid), HEDTA (hydroxyethylethylenediaminetriacetic acid), GEDTA (glycol ether diamine tetraacetic acid) Acetic acid), TTHA (triethylenetetramine hexaacetic acid), HIDA (hydroxyethyliminodiacetic acid), DHEG (hydroxyethylglycine) and the like can be mentioned as examples, but are not limited thereto.

  As described above, according to the substrate processing apparatus of the present invention, the processing liquid can be reused by adsorbing and removing indium ions and tin ions in the processing liquid. Costs for substrate processing can be suppressed. Further, indium ions and tin ions can be removed from the treatment liquid without reducing the adsorption capacity, which is efficient. In addition, if the processing liquid is always circulated through the adsorption tower during the substrate processing, the substrate processing can be continuously performed while suppressing the concentration of indium ions and tin ions in the processing liquid to a certain level or less. Generation | occurrence | production can be prevented or a substrate process can be performed at lower cost.

It is the block diagram which showed schematic structure of the substrate processing apparatus which concerns on one Embodiment of this invention. It is the graph which showed the relationship between the quantity of the etching liquid which flowed through the column, and the density | concentration of the indium ion contained in the etching liquid after liquid flow. It is the graph which showed the relationship between the quantity of the sulfuric acid which flowed through the column, the density | concentration of the indium ion contained in the sulfuric acid after liquid flow, and the ratio (elution rate) which the indium adsorb | sucked to the chelating agent eluted with sulfuric acid. It is the block diagram which showed schematic structure of the etching liquid processing apparatus which concerns on other embodiment of this invention.

  Hereinafter, specific embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a configuration diagram showing a schematic configuration of a substrate processing apparatus according to an embodiment of the present invention.

  As shown in FIG. 1, in the substrate processing apparatus 1 of this example, an indium tin oxide film (metal film) is formed on the upper surface using, for example, an etching solution L having an oxalic acid concentration (wt%) of about 3%. An etching process is performed on the substrate K. The storage tank 11 that stores the etching liquid L, the substrate processing mechanism 12 that etches the substrate K with the etching liquid L, and the etching liquid between the storage tank 11 and the substrate processing mechanism 12. A first etching solution circulation mechanism (circulation mechanism for etching process) 20 that circulates L, a removal mechanism 30 that removes indium and tin (metal) dissolved in the etching solution L, and the like are included.

  The substrate processing apparatus 1 includes a concentration sensor 24 that detects the oxalic acid concentration of the etching liquid L stored in the storage tank 11 (the concentration of the component that contributes to the etching process), and the etching liquid L stored in the storage tank 11. A concentration adjusting mechanism 25 for adjusting the concentration of oxalic acid, and a control device 28 for controlling operations of the substrate processing mechanism 12, the first etching solution circulation mechanism 20, the removal mechanism 30, and the like. The control device 28 includes a first control unit 28 a that controls the substrate processing mechanism 12 and the first etching solution circulation mechanism 20, and a second control unit 28 b that controls the removal mechanism 30. Moreover, in the said structure, the said storage tank 11, the removal mechanism 30, and the 2nd control part 28b function as the etching liquid processing apparatus 5. FIG.

  The substrate processing mechanism 12 includes a processing chamber 13 having a closed space, and a plurality of transport rollers disposed in a lower portion of the processing chamber 13 and supporting the substrate K horizontally and transporting the substrate K in a predetermined direction (arrow direction). 14 and an upper part in the processing chamber 13, a flow pipe 15 through which the etching liquid L supplied by the first etching liquid circulation mechanism 20 flows, and a flow pipe 15 fixed to the flow pipe 15 and transported by the transport roller 14. The etching liquid L in the processing chamber 13 is discharged from a discharge port 13a formed on the bottom surface of the processing chamber 13 to the outside. It has come to be.

  The operation of the first etchant circulation mechanism 20 is controlled by a supply pipe 21 having one end connected to the storage tank 11 and the other end connected to the flow pipe 15 and the first control unit 28a. A supply pump 22 for supplying the etching solution L into the flow pipe 15 and a recovery pipe 23 having one end connected to the discharge port 13a of the processing chamber 13 and the other end connected to the storage tank 11 are formed.

  The removal mechanism 30 includes a metal ion adsorption mechanism 31 that adsorbs indium ions and tin ions (metal ions) dissolved in the etchant L by the etching process in the substrate processing mechanism 12 and included in the etchant L. The second etching solution circulation mechanism (removal processing circulation mechanism) 34 that circulates the etching solution L between the storage tank 11 and the metal ion adsorption mechanism 31 and the indium and tin adsorbed by the metal ion adsorption mechanism 31 are eluted. An eluent supply mechanism 42 for supplying an eluent to be discharged, an eluent recovery mechanism 48 for recovering the eluent from the metal ion adsorption mechanism 31, and a cleaning liquid supply mechanism for supplying a cleaning liquid for cleaning the metal ion adsorption mechanism 31. 54 and a cleaning liquid recovery mechanism 58 that recovers the cleaning liquid from the metal ion adsorption mechanism 31.

  The metal ion adsorption mechanism 31 includes at least two adsorption towers (first adsorption tower 32 and second adsorption tower 33) filled with a chelating agent (not shown) that adsorbs indium ions and tin ions. The chelating agent (not shown) is a general term for organic aminocarboxylates, and adsorbs metal ions and elutes the adsorbed metal by a specific solution. It is equipped with. Specifically, EDTA (ethylenediaminetetraacetic acid), NTA (nitrilotriacetic acid), DTPA (diethylenetriaminepentaacetic acid), GLDA (L-glutamic acid diacetic acid), HEDTA (hydroxyethylethylenediaminetriacetic acid), GEDTA (glycol ether diamine tetraacetic acid) Acetic acid), TTHA (triethylenetetramine hexaacetic acid), HIDA (hydroxyethyliminodiacetic acid), DHEG (hydroxyethylglycine) and the like can be mentioned as examples, but are not limited thereto.

  The operation of the second etchant circulation mechanism 34 is controlled by an etchant supply pipe 35 having one end connected to the storage tank 11, the other end branched and connected to the adsorption towers 32 and 33, and the second controller 28b. The supply pump 36 that supplies the etchant L to the inside of each adsorption tower 32, 33 via the etchant supply pipe 35, one end side is connected to the storage tank 11, and the other end side branches to each adsorption tower 32, 33, an etching solution recovery pipe 37 connected to the first supply side switching valve 38 and a second supply side switching valve 39 provided at the other end side branch of the etching solution supply pipe 35, and an etching solution recovery pipe 37. The first discharge side switching valve 40 and the second discharge side switching valve 41 are provided at the other end side branch section, respectively.

  When the first supply side switching valve 38 and the first discharge side switching valve 40 are open, each of the switching valves 38, 39, 40, and 41 is provided with the second supply side switching valve 39 and the second discharge side switching valve 41. When the second supply side switching valve 39 and the second discharge side switching valve 41 are open so as to be closed, the second control unit 28b is closed so that the first supply side switching valve 38 and the first discharge side switching valve 40 are closed. Controlled by.

  In the second etching liquid circulation mechanism 34, when the supply pump 36 is driven, the adsorption towers 32 and 33 to which the etching liquid L is supplied are controlled by the supply side switching valves 38 and 39, and the etching liquid in the storage tank 11. L is supplied to one of the adsorption towers 32 and 33 through the etching solution supply pipe 35. That is, when the first supply side switching valve 38 is opened and the second supply side switching valve 39 is closed, the etching solution L is supplied to the first adsorption tower 32, the first supply side switching valve 38 is closed, and the second supply side switching valve 38 is closed. When the supply side switching valve 39 is open, the etching solution L is supplied to the second adsorption tower 33.

  Then, the etching liquid L that is supplied to one of the adsorption towers 32 and 33 and circulates in the adsorption towers 32 and 33 enters the storage tank 11 from the adsorption towers 32 and 33 through the etching liquid recovery pipe 37. To be recovered.

  The operation of the eluent supply mechanism 42 is controlled by the second controller 28b. For example, the eluent supply mechanism 43 for supplying an eluent composed of hydrochloric acid or sulfuric acid and one end side of the eluent supply mechanism 42 are connected to the supply unit 43 and the other end side branches. The operation is controlled by the eluent supply pipe 44 connected to each of the adsorption towers 32 and 33, the second controller 28b, the eluent supply valve 45 provided on one end side of the eluent supply pipe 44, and the eluent supply. The first supply-side switching valve 46 and the second supply-side switching valve 47 are provided at the other end side branch portion of the pipe 44. Each of the switching valves 46, 47 is opened by the first supply-side switching valve 46. When the second supply side switching valve 47 is open, the second supply side switching valve 47 is closed. When the second supply side switching valve 47 is open, the first supply side switching valve 46 is closed. .

  The eluent recovery mechanism 48 includes a recovery unit 49 that recovers the eluent, an eluent recovery pipe 50 that has one end connected to the recovery unit 49 and the other end branched and connected to the adsorption towers 32 and 33, and elution The operation is controlled by a first discharge side switching valve 51 and a second discharge side switching valve 52 and a second control unit 28b respectively provided at the other end side branch portion of the liquid recovery pipe 50, and one end of the eluate recovery pipe 50 is controlled. Each of the switching valves 51, 52 is configured so that the second discharge side switching valve 52 is closed when the first discharge side switching valve 51 is open. When the discharge side switching valve 52 is open, the second control unit 28b controls the first discharge side switching valve 51 to close.

  In the eluent supply mechanism 42 and the eluent recovery mechanism 48, when the supply unit 43 is driven, the elution liquid is supplied while the adsorption towers 32 and 33 to which the eluent is supplied are controlled by the supply side switching valves 46 and 47. It is supplied from the section 43 to one of the adsorption towers 32 and 33 via the eluent supply pipe 44. That is, when the first supply-side switching valve 46 is open and the second supply-side switching valve 47 is closed, the eluent is supplied to the first adsorption tower 32, the first supply-side switching valve 46 is closed, and the second supply When the side switching valve 47 is open, the eluent is supplied to the second adsorption tower 33.

  The eluent supplied to one of the adsorption towers 32 and 33 and flowing through the adsorption towers 32 and 33 is recovered from the adsorption towers 32 and 33 into the recovery unit 49 via the eluent recovery pipe 50. Is done. When the first supply side switching valve 46 is open, the first discharge side switching valve 51 is open, the second discharge side switching valve 52 is closed, and when the second supply side switching valve 47 is open. The second discharge side switching valve 52 is opened, and the first discharge side switching valve 51 is closed. Further, when the supply unit 43 is driven, the eluent supply valve 45 and the eluent recovery valve 53 are opened.

  The operation of the cleaning liquid supply mechanism 54 is controlled by the second control unit 28b. For example, a supply unit 55 that supplies a cleaning liquid made of pure water, one end side is connected to the supply unit 55, and the other end side is an eluent supply pipe 44. The operation is controlled by the cleaning liquid supply pipe 56 connected to each of the adsorption towers 32 and 33 via the eluent supply pipe 44 and the second control section 28b. The cleaning liquid supply valve 57 provided in the pipe 56, the first supply side switching valve 46, the second supply side switching valve 47, and the like are provided. The switching valves 46 and 47 are switched to the first supply side switching as described above. When the valve 46 is open, the second supply side switching valve 47 is closed. When the second supply side switching valve 47 is open, the second control unit 28b is closed. Controlled by.

  The cleaning liquid recovery mechanism 58 has a recovery part 59 for recovering the cleaning liquid, one end side connected to the recovery part 59, and the other end side connected between the branch part of the eluent recovery pipe 50 and the eluent recovery valve 53, A cleaning liquid recovery pipe (cleaning liquid discharge pipe) 60 connected to each adsorption tower 32, 33 via the eluent recovery pipe 50, the first discharge side switching valve 51, the second discharge side switching valve 52, and a second control unit. The operation is controlled by 28b, and includes a cleaning liquid recovery valve 61 provided on the other end side of the cleaning liquid recovery pipe 60. The switching valves 51 and 52 are similar to the above in that the first discharge side switching valve 51 is opened. The second control unit 28b controls the second discharge side switching valve 52 so that the first discharge side switching valve 51 is closed when the second discharge side switching valve 52 is open.

  In the cleaning liquid supply mechanism 54 and the cleaning liquid recovery mechanism 58, when the supply unit 55 is driven, the cleaning liquid is supplied from the supply unit 55 while the adsorption towers 32 and 33 to which the cleaning liquid is supplied are controlled by the supply side switching valves 46 and 47. It is supplied to one of the adsorption towers 32 and 33 via the supply pipe 56 and the eluent supply pipe 44. That is, when the first supply side switching valve 46 is opened and the second supply side switching valve 47 is closed, the cleaning liquid is supplied to the first adsorption tower 32, the first supply side switching valve 46 is closed, and the second supply side switching valve 46 is closed. When the switching valve 47 is open, the cleaning liquid is supplied to the second adsorption tower 33.

  The cleaning liquid supplied to one of the adsorption towers 32 and 33 and circulated through the adsorption towers 32 and 33 is recovered from the adsorption towers 32 and 33 via the eluent recovery pipe 50 and the cleaning liquid recovery pipe 60. 59 is recovered. When the first supply side switching valve 46 is open, the first discharge side switching valve 51 is open, the second discharge side switching valve 52 is closed, and when the second supply side switching valve 47 is open. The second discharge side switching valve 52 is opened, and the first discharge side switching valve 51 is closed. When the supply unit 55 is driven, the cleaning liquid supply valve 57 and the cleaning liquid recovery valve 59 are opened.

  The concentration adjusting mechanism 25 includes, for example, a supply unit 26 that supplies oxalic acid or pure water into the storage tank 11, a supply pipe 27 that has one end connected to the supply unit 26, and the other end connected to the storage tank 11; The first control unit 28a is configured to control the operation of the supply unit 26 based on the oxalic acid concentration detected by the concentration sensor 24.

  The first controller 28 a controls the supply pump 22 of the first etchant circulation mechanism 20 to circulate the etchant L between the storage tank 11 and the substrate processing mechanism 12. Further, the first control unit 28a controls the supply unit 26 based on the oxalic acid concentration detected by the concentration sensor 24, so that the oxalic acid concentration of the etching solution L stored in the storage tank 11 is within a preset range. maintain. For example, when the oxalic acid concentration detected by the concentration sensor 24 is higher than the preset range, pure water is supplied to the storage tank 11, and the oxalic acid concentration detected by the concentration sensor 24 is lower than the preset range. In this case, oxalic acid is supplied to the storage tank 11 so that the oxalic acid concentration of the etching solution L is within a preset range. The first control unit 28a transmits a signal (a start signal and an end signal) to the second control unit 28b when the circulation of the etching solution L by the first etching solution circulation mechanism 20 starts and ends. To do.

  When the second control unit 28b receives the start signal from the first control unit 28a, the second control unit 28b controls the supply pump 36 and the switching valves 38, 39, 40, and 41 of the second etching solution circulation mechanism 34, thereby controlling the etching solution. A process of supplying and circulating the etchant L in the storage tank 11 to one of the adsorption towers 32 and 33 while alternately switching the adsorption towers 32 and 33 to which L is supplied at predetermined time intervals. When the adsorption towers 32 and 33 to which the etching liquid L is supplied are switched, the elution liquid supply mechanism is first applied to the adsorption towers 32 and 33 whose supply of the etching liquid L is stopped by the switching of the adsorption towers 32 and 33. 42 controls the supply unit 43, the eluent supply valve 45, the switching valves 46, 47, and the switching valves 51, 52 and the eluent recovery valve 53 of the eluent recovery mechanism 48 to supply the eluent for a predetermined time. A process of supplying the cleaning liquid for a predetermined time by controlling the supply section 54 of the cleaning liquid supply mechanism 54, the cleaning liquid supply valve 57 and the switching valves 46 and 47, and the switching valves 51 and 52 and the cleaning liquid recovery valve 61 of the cleaning liquid recovery mechanism 58. Execute. The second controller 28b stops the circulation of the etchant L by the second etchant circulation mechanism 34 when receiving the end signal from the first controller 28a.

  According to the substrate processing apparatus 1 of the present example configured as described above, the etching solution L stored in the storage tank 11 is supplied by the first etching solution circulation mechanism 20 under the control of the first control unit 28a. 22 is supplied to each nozzle body 16 via the supply pipe 21 and the flow pipe 15 and discharged from the nozzle body 16 toward the upper surface of the substrate K. Then, the etching liquid L discharged onto the upper surface of the substrate K flows through the collection pipe 23 from the discharge port 13a of the processing chamber 13 and is collected in the storage tank 11, and thus the etching liquid in the storage tank 11 is collected. L circulates between the storage tank 11 and the substrate processing mechanism 12.

  The substrate K is transported in a predetermined direction by transport rollers 14 and is etched by the etching solution L (oxalic acid in the etching solution L) discharged from each nozzle body 16. By this etching process, the indium tin oxide film of the substrate K is dissolved in the etching solution L, and the etching solution L contains indium ions and tin ions.

  The etching solution L stored in the storage tank 11 is controlled by the second control unit 28b through the etching solution supply pipe 35 by the supply pump 36 and the switching valves 38 and 39 of the second etching solution circulation mechanism 34. Is selectively supplied to one of the adsorption towers 32 and 33, and after being circulated through the adsorption towers 32 and 33, it is recovered in the storage tank 11 through the etching liquid recovery pipe 37, and is stored in the storage tank 11. And the adsorption towers 32 and 33 are circulated. As a result, indium ions and tin ions in the etching solution L are adsorbed by the chelating agent (not shown) filled in the adsorption towers 32 and 33.

  The adsorption towers 32, 33 to which the etchant L is supplied are controlled at predetermined time intervals by controlling the switching valves 38, 39, 40, 41 of the second etchant circulation mechanism 34 by the second controller 28b. In other words, the indium and tin adsorbed by the chelating agents (not shown) of the adsorption towers 32 and 33 are alternately switched at a time interval estimated to reach a substantially saturated state. When the supplied adsorption towers 32 and 33 are switched, the following processing is executed by the second control unit 28b.

  That is, first, the second control unit 28b controls the supply unit 43 of the eluent supply mechanism 42, the eluent supply valve 45 and the switching valves 46 and 47, and the switching valves 51 and 52 of the eluent recovery mechanism 48 and the eluent recovery valve. 53 is controlled to the adsorption towers 32 and 33 in which the supply of the etching solution L is stopped by switching the adsorption towers 32 and 33 (when the first adsorption tower 32 is switched to the second adsorption tower 33, the first The eluent is supplied from the supply unit 43 via the eluent supply pipe 44 to the adsorption tower 32 (when the second adsorption tower 33 is switched to the first adsorption tower 32). The liquid is collected in the collection unit 49 via the eluent collection pipe 50 after flowing through the adsorption towers 32 and 33. Thereby, indium and tin adsorbed by the chelating agent (not shown) of the adsorption towers 32 and 33 are eluted by this eluent, and the eluent containing the eluted indium ions and tin ions is recovered in the recovery unit 49. The

  Thereafter, the second control unit 28b controls the supply unit 54 of the cleaning liquid supply mechanism 54, the cleaning liquid supply valve 57 and the switching valves 46 and 47, and the switching valves 51 and 52 and the cleaning liquid recovery valve 61 of the cleaning liquid recovery mechanism 58. As a result, the cleaning liquid is supplied from the supply unit 55 to the same adsorption towers 32 and 33 as the adsorption towers 32 and 33 to which the eluent is supplied via the cleaning liquid supply pipe 56 and the eluent supply pipe 44, and the supplied cleaning liquid is After flowing through the adsorption towers 32, 33, they are recovered in the recovery part 59 via the eluent recovery pipe 50 and the cleaning liquid recovery pipe 60. As a result, the eluent remaining in the adsorption towers 32 and 33 is washed away by the cleaning liquid.

  In this way, when the eluent and the cleaning liquid are sequentially supplied to the adsorption towers 32 and 33 from which the supply of the etching liquid L has been stopped, the adsorption towers 32 and 33 thereafter enter a standby state. In addition, by switching the adsorption towers 32 and 33 to which the etching solution L is supplied in this way, the adsorption capability of indium ions and tin ions in the metal ion adsorption mechanism 31 is maintained constant, and the indium ions in the etching solution L are maintained. Concentration and tin ion concentration are kept below a certain level.

  Note that the oxalic acid concentration of the etching solution L stored in the storage tank 11 is maintained within a predetermined range by the concentration adjusting mechanism 25. Further, the etching solution L is continuously circulated in the adsorption towers 32 and 33 from the time when the second control unit 28b receives the start signal until the end signal is received, that is, while the etching process is being performed. The etching process is performed while removing indium ions and tin ions from the etching solution L.

  Thus, according to the substrate processing apparatus 1 of this example, while the substrate K is being etched by the substrate processing mechanism 12, the etching liquid L in the storage tank 11 is removed by the second etching liquid circulation mechanism 34. The adsorption towers 32 and 33 supplied by L are alternately switched between one of the adsorption towers 32 and 33 and the indium ions and tin ions in the etching liquid L are chelated in the adsorption towers 32 and 33. When the adsorption towers 32 and 33 for supplying the etching liquid L are switched while being adsorbed by the agent (not shown), the eluent is supplied to the adsorption towers 32 and 33 for which the supply of the etching liquid L is stopped by the eluent supply mechanism 42. And a process of eluting indium and tin adsorbed on the chelating agent (not shown) to regenerate the chelating agent (not shown), and a cleaning liquid supply mechanism 54 Since the cleaning liquid is supplied to the adsorption towers 32 and 33 after the supply of the eluent, and the eluent remaining in the adsorption towers 32 and 33 is washed away, indium ions and tin ions are efficiently removed. The etching solution L can be removed, the indium ion concentration or the tin ion concentration in the etching solution L can be suppressed to a certain level to prevent etching defects, the substrate processing mechanism 12 can be operated continuously without being stopped, or the etching solution L Therefore, the replacement cycle of the etchant L can be lengthened.

  In addition, since the etching process efficiency is not lowered by the continuous execution of the etching process and the replacement cycle of the etching solution L becomes longer, the etching process cost can be kept low.

  Further, the supply of the etching solution L is stopped, and the eluent is supplied to the adsorption towers 32 and 33 where the chelating agent (not shown) has adsorbed the indium ions and tin ions, and the elution containing the eluted indium ions and tin ions is performed. Since the liquid is recovered in the recovery part 49, the chelating agent (not shown) can be regenerated, and the indium ions and tin ions in the recovered eluent can be recovered as appropriate, so that the etching solution Indium (which is a very expensive metal) and tin dissolved in L can be effectively recovered.

  In addition, after the eluent is supplied by the eluent supply mechanism 42, the cleaning liquid is supplied to the adsorption towers 32 and 33 to which the eluent is supplied by the cleaning liquid supply mechanism 54, and the eluent remaining in the adsorption towers 32 and 33. When the etching liquid L in the storage tank 11 is supplied to the adsorption towers 32 and 33, the etching liquid L and the eluent remaining in the adsorption towers 32 and 33 are mixed and etched. It is possible to effectively prevent the components of the liquid L from changing and adversely affecting the etching process in the substrate processing mechanism 12.

  Further, since the oxalic acid concentration of the etching solution L stored in the storage tank 11 is maintained within a predetermined range by the concentration adjusting mechanism 25, the concentration in the storage tank 11 can be increased by etching processing in the substrate processing mechanism 12. The inconvenience that the oxalic acid concentration of the etching solution L fluctuates and the predetermined etching ability cannot be obtained can be prevented, and the etching processing ability by the etching solution L can be maintained in an optimum state.

  By the way, the result of conducting an adsorption experiment of metal ions using “Kyrest Fiber GRY-L (trade name)” manufactured by Kyrest Co., Ltd. as a chelating agent will be described below.

  That is, first, a column having an inner diameter of 1.5 cm was prepared, and the chelating agent having a weight of 4 g, a height of 11 cm, and a volume of 19.4 mL was filled in the column, and then an oxalic acid-containing etching solution was used. Then, a predetermined amount of the etching solution that was subjected to the etching treatment and contained metal ions was passed from the one end side to the other end side of the column at a flow rate of 3 mL / min.

  In this way, after passing a predetermined amount of liquid, the etching solution that passed through the column was sampled, and the content concentration of metal ions was measured. As a result, the indium ion concentration of the etching solution before flowing was 277 ppm, and the tin ion concentration was The indium ion concentration of the etching solution after passing through the column was 8 ppm, the tin ion concentration was 0.1 ppm or less, and the aluminum ion concentration was 0.1 ppm or less, whereas 33.7 ppm and the aluminum ion concentration was 0.24 ppm. All metal ions were reduced to a very low concentration.

  This shows that metal ions such as indium ions, tin ions and aluminum ions present in the etching solution can be effectively removed by the chelating agent.

  In addition, using the same column and chelating agent as described above, the same etching solution as above is supplied to the column at the same flow rate as above, and the etching solution after passing is sampled every time a certain amount is passed, The concentration of indium ions contained in the etching solution after passing through was measured. The result is shown in FIG. In FIG. 2, BV (Bed Volume) is the volume of the chelating agent filled in the column, and (mL) / (mL-fiber) is (etching passed through the column). (Amount of liquid) / (volume of chelating agent packed in the column). Therefore, the horizontal axis indicates how much etching solution corresponding to the volume of the chelating agent is passed.

  From FIG. 2, indium ions are not detected in the etching solution after passing through until the passing amount of the etching solution reaches a predetermined amount (an amount corresponding to about 11 times the volume of the chelating agent). Is completely adsorbed by the chelating agent. It can also be seen that the chelating agent adsorption capacity does not decrease even when a large amount of the etching solution is supplied.

  Next, the results of an experiment in which the metal ions are eluted from the chelating agent having the metal ions adsorbed as described above will be described below.

That is, using the same column and chelating agent as described above, supplying a predetermined amount of the same etching solution to the column at the same flow rate as above and allowing the chelating agent to adsorb indium ions, then one end of this column. 1N sulfuric acid (1N-H ₂ SO ₄ ) is passed from the side toward the other end at a flow rate of 1.5 mL / min, and the sulfuric acid after passing is sampled every time a certain amount is passed. Then, the concentration of indium ions contained in the sulfuric acid after passing through was measured. The result is shown in FIG. In FIG. 3, BV (Bed Volume) is the volume of the chelating agent packed in the column, and (mL) / (mL-fiber) is (sulfuric acid passed through the column). ) / (Volume of chelating agent packed in the column). Therefore, the horizontal axis indicates how much sulfuric acid corresponding to the volume of the chelating agent is passed.

  In addition, in the measurement of the indium ion concentration in the previous section, the product of the indium ion concentration at each time point until the indium ion was not recognized in the sulfuric acid after the liquid flow and the liquid flow rate during that time zone was eluted at each time point. In addition to calculating the amount of indium, the total value is calculated as the total amount of indium eluted, and the value obtained by dividing the total amount of indium eluted by the amount of indium eluted at each time point is the elution rate at each time point (adsorbed to the chelating agent) The ratio of indium that has been eluted by sulfuric acid) is defined and is also shown in FIG.

  From FIG. 3, when the indium adsorbed on the chelating agent is eluted by sulfuric acid, and the amount of sulfuric acid passing through reaches a predetermined amount (an amount corresponding to about 2.8 times the volume of the chelating agent), the chelating agent It can be seen that the indium adsorbed on is completely eluted. Further, it can be seen that the chelating agent adsorbed with indium can be effectively regenerated with sulfuric acid, and the metal adsorbed on the chelating agent can be effectively recovered with sulfuric acid.

  As mentioned above, although one Embodiment of this invention was described, the specific aspect which this invention can take is not limited to this at all.

  In the above example, the adsorption towers 32 and 33 for supplying the etching liquid L are alternately switched at a predetermined time interval. However, the present invention is not limited to this. For example, the substrate K etched by the substrate processing mechanism 12 is used. The adsorption towers 32 and 33 are controlled to be switched based on the number of the above and the adsorption towers 32 and 33 are controlled to be switched based on the indium ion concentration and the tin ion concentration in the etching solution L stored in the storage tank 11. It may be configured.

  When switching control is performed based on the number of etched substrates K, the substrate processing mechanism 12 is disposed at an appropriate position, for example, outside or inside the processing chamber 13, and the substrate K or the substrate K carried into the processing chamber 13 A sensor (not shown) for detecting the substrate K unloaded from the processing chamber 13 is further provided, and the first controller 28a counts the number of substrates K etched by the substrate processing mechanism 12. The number of substrates K loaded into the processing chamber 13 or the substrate K unloaded from the processing chamber 13 based on an output signal obtained from the sensor (not shown). In addition to the process of counting the number of sheets (the number of substrates K etched by the substrate processing mechanism 12) and the start signal and the end signal, the counted number is preset. And a process of transmitting a signal (switching signal) to that effect to the second control unit 28b when the number reaches the second number, and the second control unit 28b The adsorption tower 36 is controlled while switching the adsorption towers 32 and 33 to which the etching liquid L is supplied when the supply pump 36 and the switching valves 38, 39, 40 and 41 are controlled and the switching signal is received from the first control unit 28a. The etching liquid L in the storage tank 11 is supplied to one of 32 and 33 and circulated. The first control unit 28a is configured to reset the count value and count again to the preset number when the counted number reaches the preset number. Further, the second control unit 28b circulates the etching solution L by the second etching solution circulation mechanism 34 from the reception of the start signal to the reception of the end signal.

  If the substrate processing apparatus 1 is configured in this way, when the counted number reaches a preset number, that is, indium and tin adsorbed by the chelating agent (not shown) of the adsorption towers 32 and 33 are present. When the number of sheets estimated to reach a substantially saturated state is reached, the switching valves 38, 39, 40, and 41 are switched, and the adsorption towers 32 and 33 to which the etching liquid L is supplied are switched.

  Therefore, even if the substrate processing apparatus 1 is configured in this way, the adsorption capacity of indium ions and tin ions in the metal ion adsorption mechanism 31 is maintained constant, and the indium ion concentration and the tin ion concentration in the etching solution L are below a certain level. Since it can be suppressed, the same effect as described above can be obtained.

  On the other hand, when switching control is performed based on the indium ion concentration or the tin ion concentration, the etching solution processing apparatus 5 detects the indium ion concentration and / or the tin ion concentration in the etching solution L stored in the storage tank 11. The second control unit 28b controls the supply pump 36 and the switching valves 38, 39, 40, 41 of the second etching liquid circulation mechanism 34 by further including a concentration detection sensor (not shown). The adsorption towers 32 and 33 to which the etching solution L is supplied when the indium ion concentration and / or tin ion concentration detected by a metal ion concentration detection sensor (not shown) becomes higher than a preset reference value. While switching, the etching liquid L in the storage tank 11 is supplied to one of the adsorption towers 32 and 33 and circulated. That.

  If the substrate processing apparatus 1 is configured in this manner, indium and tin adsorbed to the chelating agents (not shown) of the adsorption towers 32 and 33 reach a substantially saturated state, and the adsorption capacity of indium ions and tin ions decreases. The indium ion concentration and / or tin ion concentration in the etching solution L stored in the storage tank 11 increases, and the indium ion concentration and / or tin ion concentration detected by a metal ion concentration detection sensor (not shown) is a predetermined reference value. Higher than that, the switching valves 38, 39, 40, 41 are switched, and the adsorption towers 32, 33 to which the etching solution L is supplied are switched.

  Therefore, even if the substrate processing apparatus 1 is configured in this way, the adsorption capacity of indium ions and tin ions in the metal ion adsorption mechanism 31 is maintained constant, and the indium ion concentration and the tin ion concentration in the etching solution L are below a certain level. Since it can be suppressed, the same effect as described above can be obtained. In addition, when the switching control of the adsorption towers 32 and 33 is performed based on the elapsed time or the number of etchings, indium or tin dissolved in the etching solution L depending on the etching conditions in the substrate processing mechanism 12 or the type of the substrate K to be etched. Since the amount of indium and tin adsorbed by the chelating agents (not shown) of the adsorption towers 32 and 33 are different from each other in time and the number of etched sheets are different, the switching time and the number of etched sheets are different. Although it is difficult to set, the switching control of the adsorption towers 32 and 33 is performed more efficiently by performing the switching control of the adsorption towers 32 and 33 based on the indium ion concentration and / or the tin ion concentration in the etching liquid L in the storage tank 11. Can be implemented automatically.

  In the above example, while the substrate processing mechanism 12 is etching the substrate K, the etching liquid L is continuously circulated through the adsorption towers 32 and 33. However, the present invention is not limited to this. When the elapsed time from the start of the process reaches a predetermined time, the etching number of the substrate K reaches a predetermined number, or the indium ion concentration or tin ion concentration in the etching solution L in the storage tank 11 exceeds a predetermined concentration In addition, the etching solution L may be circulated through the adsorption towers 32 and 33 in order to remove indium ions and tin ions.

  In the above example, the etching solution processing apparatus 5 is provided in the substrate processing apparatus 1. However, the present invention is not limited to this. For example, an etching solution processing apparatus 6 as shown in FIG. 4 may be used. The etching solution processing apparatus 6 includes a removal treatment storage tank 70, the removal mechanism 30, and the second control unit 28b. The storage tank 70 is attached to the substrate processing mechanism 12. The used etching solution L is appropriately collected from the etching storage tank 11. In the etching solution processing apparatus 6 shown in FIG. 4, the same components as those of the substrate processing apparatus 1 shown in FIG.

  In this case, the etching liquid L in the storage tank 70 is circulated between the storage tank 70 and one of the adsorption towers 32 and 33 by the second etching liquid circulation mechanism 34 under the control of the second control unit 28b. The indium ions and tin ions in the etching solution L are adsorbed and removed by a chelating agent (not shown) in the adsorption towers 32 and 33. At this time, the adsorption towers 32 and 33 to which the etching liquid L is supplied are switched alternately at predetermined time intervals, for example.

  Then, a certain period of time has passed since the etching liquid L in the storage tank 70 began to be supplied to the adsorption towers 32 and 33, or the indium ion concentration and tin ion concentration of the etching liquid L in the storage tank 70 are set in advance. If lower than that, the circulation of the etching solution L is stopped, and the removal process of indium ions and tin ions is completed. Thereafter, the etching solution L after the removal process in the storage tank 70 is appropriately returned to the etching storage tank 11.

  In addition, after the eluent is supplied by the eluent supply mechanism 42, the cleaning liquid is supplied by the cleaning liquid supply mechanism 54 to the adsorption towers 32 and 33 whose supply of the etching liquid L is stopped by switching the adsorption towers 32 and 33. The supplied eluent is recovered by the eluent recovery mechanism 48, and the supplied cleaning liquid is recovered by the cleaning liquid recovery mechanism 58.

  Such an etching solution processing apparatus 6 also adsorbs indium ions and tin ions in the etching solution L by circulating the etching solution L in the storage vessel 70 between the storage vessel 70 and the adsorption towers 32 and 33. Since the etching liquid L can be removed and reused, the cost of the etching liquid L can be suppressed by eliminating the purchase cost of the new etching liquid L and the disposal cost of the used etching liquid L. The cost for the etching process can be reduced.

  Further, since the etching liquid L in the storage tank 70 is circulated while switching the adsorption towers 32 and 33 to which the etching liquid L is supplied, the adsorption capacity of the adsorption towers 32 and 33 for the indium ions and tin ions is reduced. Indium ions and tin ions can be removed from the etching solution L, and indium ions and tin ions can be efficiently removed.

  In the above example, the etching solution L having an oxalic acid concentration of about 3% is used to perform an etching process on the substrate K having an indium tin oxide film formed on the upper surface, and indium and tin dissolved in the etching solution K are recovered. However, the type of the etchant L and the type of metal to be collected are not limited to these.

  In the above example, the substrate K is configured to perform the etching process. However, a development process, a cleaning process, and the like may be performed. The substrate K may include a semiconductor (silicon) wafer, a liquid crystal glass substrate, Various substrates K such as a photomask glass substrate and an optical disk substrate are included. Further, the metal ion adsorption mechanism 31 may be configured to include three or more adsorption towers 32 and 33.

  Furthermore, in the above example, the switching valves 38, 39, 40, 41 of the second etching liquid circulation mechanism 34, the supply unit 43 of the eluent supply mechanism 42, the eluent supply valve 45, and the switch valves 46, 47, The switching valves 51 and 52 and the eluent recovery valve 53 of the eluent recovery mechanism 48, the supply unit 54 of the cleaning liquid supply mechanism 54, the cleaning liquid supply valve 57 and the switching valves 46 and 47, and the switching valves 51 of the cleaning liquid recovery mechanism 58, 52, the operation control of the cleaning liquid recovery valve 61 is performed by the second control unit 28b. However, it may be configured such that the operator manually operates it.

  In the above example, the control device 28 includes the first control unit 28a and the second control unit 28b. However, the present invention is not limited to this, and the function of the first control unit 28a and the function of the second control unit 28b. May be provided in one control unit.

DESCRIPTION OF SYMBOLS 1 Substrate processing apparatus 5 Etching liquid processing apparatus 11 Reservoir 12 Substrate processing mechanism 20 1st etching liquid circulation mechanism 24 Concentration sensor 25 Concentration adjustment mechanism 28 Control apparatus 28a 1st control part 28b 2nd control part 30 Removal mechanism 31 Metal ion adsorption | suction Mechanism 32 First adsorption tower 33 Second adsorption tower 34 Second etching liquid circulation mechanism 35 Etching liquid supply pipe 36 Supply pump 37 Etching liquid recovery pipe 38, 39, 40, 41 Switching valve 42 Eluent supply mechanism 43 Supply section 44 Elution Liquid supply pipe 45 Eluent supply valve 46, 47 Switching valve 48 Eluent recovery mechanism 49 Recovery section 50 Eluent recovery pipe 51, 52 Switching valve 53 Eluent recovery valve 54 Cleaning liquid supply mechanism 55 Supply section 56 Cleaning liquid supply pipe 57 Cleaning liquid supply Valve 58 Cleaning liquid recovery mechanism 59 Recovery section 60 Cleaning liquid recovery pipe 61 Cleaning liquid recovery valve K group L etching solution

Claims (7)

A storage tank for storing a treatment liquid containing oxalic acid;
A processing means that includes a processing chamber and a nozzle body that is disposed in the processing chamber and that discharges the processing liquid, and that processes the substrate on which the indium tin oxide film is formed with the processing liquid discharged from the nozzle body. When,
A first supply pipe for supplying the processing liquid in the storage tank to the nozzle body, a first supply pump provided in the first supply pipe, and a first recovery for connecting the storage tank and the processing chamber. And a processing liquid in the storage tank is supplied to the nozzle body and discharged by the first supply pipe and the first supply pump, and the discharged processing liquid is supplied to the processing chamber by the first recovery pipe. The substrate processing circulation means for recovering in the storage tank and circulating the processing liquid between the storage tank and the processing means,
An adsorption means comprising at least two adsorption towers arranged side by side, each of the adsorption towers filled with a chelating agent that adsorbs indium ions and tin ions in the treatment liquid;
One end is connected to the storage tank, the other end is branched and connected to each adsorption tower, and a second supply pipe for supplying the treatment liquid in the storage tank to each adsorption tower; A second supply pump provided between one end of the supply pipe and the branch part; a first switching valve provided in the second supply pipe for controlling the supply of the processing liquid to each adsorption tower; A second recovery pipe for recovering the processing liquid flowing through each adsorption tower in the storage tank, and selecting one of the adsorption towers by switching the first switching valve A substrate processing apparatus comprising a removal processing circulation means for supplying and circulating the processing solution.   2. The substrate processing apparatus according to claim 1, further comprising control means for switching the first switching valve at a preset time interval. Counting means for counting the number of substrates processed by the processing means, and outputting a switching signal when the counted number reaches a preset number;
The substrate processing apparatus according to claim 1, further comprising a control unit that receives the switching signal output from the counting unit and switches the first switching valve. Concentration detection means for detecting the ion concentration of at least one of indium ions and tin ions in the treatment liquid stored in the storage tank;
2. The substrate according to claim 1, further comprising control means for switching the first switching valve when an ion concentration detected by the concentration detection means becomes higher than a preset reference value. Processing equipment. An eluent supply pipe for supplying the elution liquid eluting the indium and tin adsorbed by the chelating agent of each adsorption tower to each adsorption tower; and the eluent supply pipe; A second switching valve for controlling the supply of the eluent, and an eluent supply means for selectively supplying the eluent to any one of the adsorption towers by switching the second switch valve. When,
An eluent recovery means for recovering the eluent flowing through each of the adsorption towers;
When the control means switches the first switching valve, the control means switches the second switching valve to stop the supply of the processing liquid and to the adsorption tower in which the chelating agent has adsorbed indium and tin. 5. The substrate processing apparatus according to claim 2, wherein the substrate processing apparatus is configured to supply an eluent. A cleaning liquid supply pipe for supplying cleaning liquid for cleaning the inside of each adsorption tower to each adsorption tower, and a third switching valve provided in the cleaning liquid supply pipe for controlling the supply of the cleaning liquid to each adsorption tower. A cleaning liquid supply means for selectively supplying the cleaning liquid to any one of the adsorption towers by switching the third switching valve;
A cleaning liquid discharge pipe for discharging the cleaning liquid flowing through each of the adsorption towers to the outside;
The control means is configured to switch the third switching valve to supply the cleaning liquid to the adsorption tower after the supply of the eluent when the supply of the eluent is completed. 5. The substrate processing apparatus according to 5. Contributing component concentration detection means for detecting the concentration of the component contributing to the substrate processing in the processing liquid stored in the storage tank;
Concentration adjusting means for adjusting the concentration of the contributing component in the processing liquid stored in the storage tank based on the contribution component concentration detected by the contributing component concentration detecting means and maintaining the concentration within a preset range. 7. The substrate processing apparatus according to claim 1, further comprising a substrate processing apparatus.

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