JP2005215627A - Method and apparatus for regenerating resist-peeling waste liquid - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and an apparatus for regenerating a resist-peeling waste liquid by which a high-quality regenerated resist peeling liquid can be obtained from a resist-peeling waste liquid, and at least the service life for regeneration and reuse of the waste liquid can be extended. <P>SOLUTION: In the process of regenerating a resist-peeling waste liquid, essentially containing a resist, alkanolamine and organic solvent to obtain a regenerated resist-peeling liquid, the resist-peeling waste liquid or a processed liquid derived from the resist-peeling waste liquid, is brought into contact with an ion exchange resin to remove metals and/or ionic impurities. Alternatively the resist peeling waste liquid or a processed liquid derived from the resist-peeling waste liquid is brought into contact with a dewatering agent or a deaeration membrane to reduce the water content; or both of these treatments are carried out. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a resist generated mainly from a manufacturing process of a semiconductor device, a flat panel display such as a liquid crystal display (LCD) or a plasma display panel (PDP), or an electronic component such as a printed circuit board, a resist mainly containing an alkanolamine and an organic solvent. The present invention relates to a method and an apparatus for regenerating a resist stripping waste liquid that regenerates the stripping waste liquid to obtain a recycled resist stripping solution.

  The manufacturing process of electronic components such as semiconductor devices, flat panel displays, and printed circuit boards includes a photolithography process. In this step, a photoresist film is formed on a substrate such as a wafer or glass substrate, light is irradiated on a predetermined portion thereof, and then unnecessary photoresist is dissolved and developed with a developer to form a resist pattern. Further, after further processing such as etching, the insoluble resist film on the substrate is peeled off. There are two types of photoresist: a positive type in which an exposed portion is soluble in a developer and a negative type in which an exposed portion is insoluble. In the field of manufacturing electronic components such as semiconductor devices and flat panel displays, positive photoresists are mainly used. In the above stripping step, a resist stripping solution is used to strip the insoluble resist film on the substrate. This stripping solution is generally composed of an organic solvent, an alkanolamine, water (0.5% by weight or less), and the like. In addition, additives such as corrosion inhibitors, chelating agents, and organic acids may be mixed in the resist stripping solution in order to prevent corrosion on electronic components due to trace amounts of metals present in the resist stripping solution. . The resist film on the substrate is dissolved using a resist stripping solution and stripped from the substrate. As a result, a resist stripping waste liquid containing a dissolved resist is generated.

As a method for regenerating the resist stripping waste liquid and regenerating the resist stripping liquid, methods disclosed in the following patent documents are known.
Japanese Patent No. 2602179 JP 2003-167358 A

  In the method disclosed in Japanese Patent No. 2602179, the concentration of the organic solvent, alkanolamine, and dissolved resist in the resist stripping waste liquid is measured with an absorptiometer, and the organic solvent and alkanolamine are supplied based on the measured concentration. It is a simple method of adjusting and reproducing the component concentration. The method disclosed in Japanese Patent Application Laid-Open No. 2003-167358 includes an organic solvent and an alkanolamine obtained by mainly removing a resist from a resist stripping waste liquid by a membrane separation process using a nanofiltration membrane (NF membrane). This is a method in which the concentration of each component of the permeate contained is adjusted by supplying an organic solvent and / or alkanolamine, and regenerated and reused in a state substantially equivalent to the original (new) resist stripper.

  In these regeneration processing methods, the removal rate of various impurities such as resists and other anions, metals such as Na, K, Ca, Fe, and Al, and cations is poor. From this point of view, it is difficult to say that the regenerated resist stripping solution is almost equivalent to the original (new) resist stripping solution, and this may cause a problem especially when it is reused for manufacturing electronic parts. Furthermore, by repeating reuse, the various impurities as described above are gradually concentrated to a high concentration. Therefore, when the concentration of various impurities increases to a certain value, it is necessary to terminate the reuse and replace the entire amount. is there.

  The water content of the resist stripping solution is usually required to be 0.5% by weight or less from the viewpoint of the stripping effect. In any of the above recycling methods, it is difficult to remove moisture mixed in the resist stripping waste liquid from the resist stripping process, etc., and the water content in the recycled resist stripping solution increases as the recycling process is repeated. The resist stripping waste liquid, which has been increased to a certain moisture content as in the case of the various impurities described above, can be reused by recycling. It is necessary to finish and replace the whole quantity.

  The waste liquids having high impurity concentrations and / or high water content generated in this manner are usually incinerated and carbon dioxide gas is released into the atmosphere along with this, which is not preferable in consideration of the environment. Moreover, in any of the above-described regeneration processing methods, it is necessary to periodically supply a new resist stripping solution, which increases the running cost.

  The present invention makes it possible to obtain a high-quality recycled resist stripping solution from a resist stripping waste solution, extending at least the recycling and recycling life, and supplying the main components and additives of a new resist stripping solution as needed. It is an object of the present invention to provide a method and an apparatus for regenerating a resist stripping waste liquid that can sufficiently reduce the above.

  In the process of regenerating a resist stripping waste liquid mainly containing a resist, an alkanolamine and an organic solvent to obtain a recycled resist stripping liquid, the resist stripping waste liquid or a processing liquid derived from the resist stripping waste liquid is contacted with an ion exchange resin. By removing the metals and / or ionic impurities, and by bringing the resist stripping waste liquid or the processing liquid derived from the resist stripping waste liquid into contact with the moisture removing agent and / or the degassing membrane. A method for regenerating a resist stripping waste liquid comprising one or both of water removal processing steps for reducing the content, and a resist stripping waste liquid mainly containing a resist, an alkanolamine, and an organic solvent. To obtain a recycled resist stripping solution, which is a resist stripping waste liquid or Ion exchange treatment equipment that removes metals and / or ionic impurities by bringing the treatment liquid derived from the resist stripping waste liquid into contact with the ion exchange resin, and water removal from the resist stripping waste liquid or the processing liquid derived from the resist stripping waste liquid The present invention provides a resist stripping waste liquid regeneration processing apparatus including one or both of a water removal processing apparatus that reduces the water content by contacting with an agent and / or a degassing membrane. . Here, the “ion exchange resin” is a concept including a chelate resin in addition to the anion exchange resin and the cation exchange resin. In addition, the “treatment liquid derived from the resist stripping waste liquid” means that when one of the ion exchange treatment and moisture removal treatment is performed and the other step is performed thereafter, the treatment liquid obtained in the one step is In the other step, it becomes “a treatment liquid derived from the resist stripping waste liquid”, and a processing liquid such as a permeate by a membrane separation process described later can also be “a processing liquid derived from the resist stripping waste liquid”.

  The resist stripping solution contains alkanolamine and an organic solvent as main components. Specific examples of the alkanolamine include monoethanolamine, diethanolamine, triethanolamine, N, N-dimethylethanolamine, N, N-diethylethanolamine, aminoethylethanolamine, N-methyl-N, N-diethanolamine, N , N-dibutylethanolamine, N-methylethanolamine, 3-amino-1-propanol and the like. The organic solvent is an organic solvent different from the alkanolamine, and specific examples thereof include a dimethyl sulfoxide-based stock solution, an N-methylpyrrolidone-based stock solution, and a glycol ether-based stock solution. In addition, additives such as corrosion inhibitors, chelating agents, and organic acids may be mixed in the resist stripping solution.

  The resist stripping waste liquid is a waste liquid generated by using the above resist stripping liquid for stripping the resist film on the substrate. Among them, resist, other anions, Na, K, Ca, Fe, Al, etc. In addition to various impurities originally included in chemicals (new resist stripping solution, alkanolamines, organic solvents, additives, etc.) There are also various impurities that are included by elution from piping materials. In addition to the water originally contained in chemicals (new resist stripping solution, alkanolamine, organic solvent, additive, etc.), there is also water that is mixed into the resist stripping waste solution from the resist stripping process. It is a feature of the present invention to remove these various impurities and / or moisture. Whether to remove various impurities or moisture, or both, may be determined in consideration of the properties of the resist stripping waste liquid and the quality required for the recycled resist stripping liquid in relation to the cost. Note that it is not always clear in what form the metals are removed.

  As the ion exchange resin used in the ion exchange treatment step, it is preferable to use an anion exchange resin and / or a cation exchange resin and / or a chelate resin of at least one of hydrogen ion type and alkanolamine type. Whether an anion exchange resin, a cation exchange resin, or a chelate resin is used alone, or a combination of two or three is used as an ion exchange resin, whether resist, other anions, metals, cation What is necessary is just to decide by the residual allowance of these impurities in relation to the kind and density | concentration of impurities, such as ions, and also the kind of electronic parts manufactured in the process using the resist stripping solution to be regenerated. However, in order to obtain a regenerated resist stripping solution with less impurities and to extend the life of recycle reuse as much as possible, it is necessary to use at least two kinds of anion exchange resin and cation exchange resin and / or chelate resin. preferable. Anion exchange resin removes anionic impurities including resist and reduces its concentration, and cation exchange resin does not remove enough metals and cationic impurities even after membrane separation treatment described later (Especially Na ions, etc.) is removed to reduce its concentration, and the chelate resin specifically removes metal ions to reduce its concentration.

In particular, in the electronic component manufacturing process, it is required to use a resist stripping solution in which the content of each metal impurity is suppressed to a lower level. Depending on the type of electronic component, at least the content of each metal impurity Is required to be less than 10 ppb, and therefore the same is required for the recycled resist stripper. In addition, additives such as a corrosion inhibitor, a chelating agent, and an organic acid may be used for the resist stripping solution in order to prevent metal adhesion and corrosion on the electronic component in the resist stripping process. As described in Japanese Patent No. 228635, these additives generally have a high content of metal impurities, and can be a source of metal impurities and prevent it as the metal content must be reduced in advance. Therefore, if the metal content reduction treatment is performed on the additive in advance, the cost is increased. Therefore, by contacting the cation exchange resin and / or chelate resin, reducing the content of metals mixed in from the resist stripping process or additives, a metal corrosion inhibitor for dealing with metal contamination, It is not necessary to reduce or use the amount of some additives such as chelating agents, and the cost can be reduced.
JP 2001-228635 A

  As the anion exchange resin, a granular or porous filtration membrane-like hydroxide ion type anion exchange resin such as styrene or acrylic is preferable, and in terms of resist removal efficiency, a styrene anion exchange resin is particularly preferable. Moreover, although a strongly basic anion exchange resin is preferable, it is not limited to these. The resist has an anionic group such as a phenolic hydroxyl group and is removed by contact with the anion exchange resin. Therefore, the ion exchange using the anion exchange resin can be performed without the membrane separation process described later. If the processing step is carried out, the resist concentration of the processing solution will decrease, but it is better to bring the permeate obtained from the membrane separation processing step described later (or a processing solution such as its water removal processing) into contact with the anion exchange resin. This is preferable because the load of the ion exchange treatment is reduced. In addition, if an anion exchange resin is used, a small amount of residual resist in the permeate (or a treatment liquid such as its water removal treatment) can be removed even when the membrane separation process described later is performed. It is also possible to achieve a low resist concentration to the extent that almost no resist remains in the solution. If an anion exchange resin is used, other anions can be removed depending on the type and concentration.

  The cation exchange resin is preferably a cation exchange resin in the form of hydrogen ion or alkanolamine, such as styrene or acrylic, or a porous filtration membrane, in terms of processing efficiency, and a weakly acidic cation exchange resin. Or a strongly acidic cation exchange resin. The use of a cation exchange resin in the form of a hydrogen ion is preferable because it is industrially simple. However, a cation exchange resin preliminarily made into an alkanolamine form is an alkanolamine in the initial stage of liquid passage in the case of a hydrogen ion type cation exchange resin. Is preferable in that it can be prevented from being adsorbed by the cation exchange resin and reducing its concentration in the treatment liquid. Even if a part of the cation exchange resin is in the alkanolamine form and the other part is in the hydrogen ion form, the resins in both forms may be mixed or laminated at an arbitrary ratio. The hydrogen ion type cation exchange resin becomes an alkanolamine type with the passage of time of the resist stripping solution or the processing solution derived from it, so that after a certain amount of time, the alkanolamine type cation exchange resin is substantially reduced. An ion exchange resin is used.

  As the chelating resin, granular or porous filtration membrane resins having a chelating group such as iminodiacetic acid type, aminophosphoric acid type, polyamine type, and glucamine type can be preferably used.

  When using at least two kinds of granular anion exchange resin, cation exchange resin, and chelate resin, they may be mixed (as a mixed bed), stacked, or used in another column. You may fill and connect and use. In the case of porous filtration membrane resins, they can be used as modules (or elements). When two or more kinds are used in a stack or in another column, or when used in another module (or element), the order is not basically limited, and any order can be adopted. However, when two or more types of granular resin and porous filtration membrane resin are used in combination, the porous filtration membrane resin is placed in the latter stage in terms of removing fine particles that may be generated from the granular resin. It is preferable to do this. When the resist concentration of the liquid to be treated (resist stripping waste liquid or treatment liquid derived therefrom) is high at the inlet of the ion exchange treatment apparatus, it is preferable to use an anion exchange resin and a cation exchange resin and / or a chelate resin. In this case, it is preferable to use an anion exchange resin by laminating a cation exchange resin and / or a chelate resin on the upstream side, or arranging another column or another module (or element). Further, after contacting with an anion exchange resin and then contacting with a cation exchange resin and / or a chelate resin, the solution is further passed through a mixed resin of an anion exchange resin and a cation exchange resin (such as a mixed bed cartridge polisher). This is preferable because a treatment liquid with a further reduced impurity concentration can be obtained and a good regenerated resist stripping liquid can be obtained. The reason why it is preferable to arrange the anion exchange resin on the upstream side and the cation exchange resin and / or the chelate resin on the downstream side is that the resist, which is a polymer substance, is adsorbed on the surface of the cation exchange resin and becomes a cation exchange resin. In addition, since the activity of the chelate resin may be reduced, it is advantageous to remove the resist in advance by contact with the anion exchange resin. In this case, when both the cation exchange resin and the chelate resin are used, either one may be arranged on the upstream side, or a mixture of both may be used. A granular resin is excellent in terms of processing efficiency, and a porous filtration membrane-like resin is preferable in that fine particles are not generated.

  Specific examples of the anion exchange resin include Amberlite 900Cl, IRA400Cl, IRA402BLCl, Amberjet 4400Cl, IRA96SB, XT6050RF, IRA478RFCl, and Amberlyst A26 manufactured by Rohm and Haas. Specific examples of the cation exchange resin include Amberlite IR124, IR120B, 200CT, IRC76, AmberJet 1060, and Amberlist 15JWET manufactured by Rohm and Haas. Specific examples of the chelate resin include Amberlite IRC748, IRC747, and IRA743 manufactured by Rohm and Haas.

  Examples of the water removal agent (drying agent) that may be used in the water removal treatment step include dry ion exchange resin, molecular sieve, silica gel, zeolite, and the like. In this case, as the moisture removal processing apparatus, for example, a column filled with such a moisture removal agent can be preferably used. The moisture content of the dry ion exchange resin is preferably 30% by weight or less, more preferably 15% by weight or less, still more preferably 10% by weight or less, and particularly preferably 1% by weight or less. preferable. Here, the dry ion exchange resin can serve both as a function of removing metals and ionic impurities and a function of removing water as a water removing agent. It is preferable in that it can be performed. In this case, the ion exchange treatment step and the water removal treatment step are actually performed in one step, and the ion exchange treatment device and the water removal treatment device actually constitute one device. Specific examples of the dry ion exchange resin include Amberlyst 15DRY (cation exchange resin) manufactured by Rohm and Haas, Amberlyst MSP · DRY (mixed bed ion exchange resin) manufactured by Organo Corporation, and Amberlyst B20. -HG · DRY (anion exchange resin), Amberlyst 15JS-HG · DRY (cation exchange resin), molecular sieve 3A as a specific example of molecular sieve, and Kanto Chemical Co., Ltd. as a specific example of silica gel As a specific example of zeolite, Zeorum A-3 manufactured by Tosoh Corporation may be mentioned.

  Examples of the deaeration film that may be used in the water removal treatment step include Liquicel manufactured by Celgard, Inc., SEPAREL manufactured by Dainippon Ink, Inc., and the like. When the resist stripping waste liquid or the treatment liquid derived therefrom is brought into contact with the degassing membrane, water having a low boiling point vaporizes and permeates the degassing membrane, and has a high boiling point and an alkanolamine that does not substantially permeate the degassing membrane. It can be separated and removed from the organic solvent. In this case, as the moisture removal processing device, for example, a membrane deaeration processing device using a deaeration membrane module (or element) can be used. A water removal agent column and a membrane degassing apparatus can be used in combination. For example, the ion exchange and moisture removal treatment process is performed with a dry ion exchange resin column, and the moisture is further removed with a membrane deaeration treatment apparatus.

  When performing both the ion exchange treatment step and the water removal treatment step, the order is not particularly limited, but when using a water removal agent containing a metal component such as molecular sieve or zeolite, it is better to perform the ion exchange treatment step in the latter stage. desirable.

  Normally, the resist stripping waste liquid and the rinse waste liquid generated from the cleaning water (rinsing water) used after resist stripping are handled separately, so alkanolamine and organic components that are components of the resist stripping waste liquid before and after ion exchange treatment and moisture removal treatment The ratio of the solvent does not change that much and is often the same as the resist stripping solution. Therefore, if the resist concentration is an acceptable value even if the resist stripping waste liquid is subjected to ion exchange treatment or moisture removal processing, the recycled resist stripping is possible. In some cases, it can be used as a liquid. However, ion separation treatment is performed on the permeate obtained by removing the resist stripping waste liquid with a membrane separation processing device and removing the resist to the concentrated liquid side at least to some extent (or processing liquid such as water removal treatment). It is preferable to use for a process. In this case, a certain amount of metals and ionic impurities including the resist are removed to the concentrated liquid side of the membrane separation process, and the permeate has a small load on the ion exchange process, particularly the anion exchange process. On the other hand, it is preferable that the water removal treatment step is performed after the membrane separation treatment in terms of avoiding contamination of the water removing agent and the degassing membrane with the resist. As the membrane separation processing apparatus, an NF membrane separation processing apparatus or a general reverse osmosis membrane separation processing apparatus can be used, but an NF membrane separation processing apparatus is preferable. When performing the membrane separation treatment step and the ion exchange treatment step, with respect to the order of the steps, the order of “membrane separation treatment such as NF membrane separation treatment → ion exchange treatment” described above is performed with metals and / or ionic impurities. Although it is preferable in terms of removal as much as possible, there is a certain effect in the order of “ion separation treatment → membrane separation treatment such as NF membrane separation treatment”, and there is a possibility that it will occur when granular ion exchange resin is used. Since certain fine particles can be removed by membrane separation, the present invention does not exclude the reverse method and apparatus. In the case of performing the membrane separation treatment step and the water removal treatment step, it is usually preferable to carry out in this order. However, depending on the type of the moisture removal agent (molecular sieve, zeolite, etc.), the water removal treatment step may be performed before the membrane separation treatment step. It may be preferable to carry out with.

  The NF membrane used in the NF membrane separation treatment apparatus has a sodium chloride rejection (removal rate) of 90% or less when the 0.2% (weight / volume) sodium chloride aqueous solution is used as a liquid to be treated at 25 ° C. The separation membrane has the following characteristics, and it is preferable that the molecular weight cutoff is within the range of 100 to 1500 if expressed in terms of the molecular weight cutoff. However, the concentrated liquid in which impurities such as resist are concentrated, alkanolamine and organic As long as it has a function of separating into a permeate containing mainly a solvent, it is not necessarily limited to this range. The molecular weight cutoff is more preferably from 200 to 1200, still more preferably from 400 to 1000. Alkanolamine and the organic solvent pass through the NF membrane and most of them enter the permeate, but the resist hardly or hardly passes through the NF membrane, and most of it remains on the concentrate side and is concentrated. Thus, a concentrated liquid mainly containing impurities such as a resist and a permeated liquid mainly containing alkanolamine and an organic solvent can be obtained. An NF membrane separation treatment apparatus that performs a membrane separation treatment step using an NF membrane is preferable in that it is relatively low cost and easy to operate, and the alkanolamine and the organic solvent can be purified to a considerable extent.

Examples of the NF membrane that can be used in the NF membrane separation treatment apparatus that may be used in the present invention include NTR-7410, NTR-7450, NTR-725HF, NTR-7250, NTR-729HF, manufactured by Nitto Denko Corporation, NTR-769SR, SU-200S, SU-500, SU-600 manufactured by Toray Industries, Inc., NF-45, NF-70, NF-90 manufactured by Filmtec, and “Sel RO ^™ manufactured by Coke Membrane Systems, Inc. MPS / T-20, MPS / T-21, MPS / T-31, MPS / T-34, MPS / T-36, MPS / T-44, MPS / T-50, MPS / T-60 Etc. Among these, “Sel RO ^™ ” series NF membranes manufactured by Cork Membrane Systems are preferable in that they have excellent alkali resistance and can be used in the entire pH range.

  In order to avoid the possibility of clogging due to fine particle impurities or the like of the NF film, it is preferable to provide a safety filter in the previous stage (preferably immediately before) of the NF film.

  As described above, the ratio of the alkanolamine, which is a component of the resist stripping waste liquid, and the organic solvent before and after the ion exchange treatment and water removal treatment does not change so much, and is often almost the same as the resist stripping solution. When purification is performed only by treatment, only moisture removal treatment, or both treatments, the treatment solution may be used without adjusting the concentration. However, in some cases, due to external factors, or when a membrane separation process such as an NF membrane separation process is performed and the ratio of the resist stripping solution is different, the ion exchange process and / or moisture removal is performed. It is preferable to further perform a step of adjusting the concentration of the alkanolamine and the organic solvent in the treatment liquid obtained through at least the treatment step. In order to perform this concentration adjustment step, a treatment liquid obtained through at least an ion exchange treatment device and / or a water removal treatment device is stored, and a concentration adjustment for adjusting the concentrations of alkanolamine and organic solvent in the treatment solution. It is preferable to use a resist stripping waste liquid regeneration treatment apparatus configured to further include a tank, an alkanolamine supply means for supplying alkanolamine to the concentration adjustment tank, and an organic solvent supply means for supplying an organic solvent to the concentration adjustment tank. This is preferable because the concentration can be easily adjusted. The concentration detector for measuring the concentration of each component for adjusting the concentration is not particularly limited as long as the concentration of each component can be measured. However, the absorption detector absorbs light having absorption wavelengths specific to resist, alkanolamine, and organic solvent. It is simple and preferable to use a photometer.

  According to the present invention, metals and / or ionic impurities and / or moisture that could not be removed by the conventional resist stripping waste liquid recycling method are ion-exchanged by an ion-exchanger using an ion-exchange resin. Since it is removed by the process and / or the water removal treatment process by the water removal treatment apparatus using a water removal agent or a degassing film, a regenerated resist stripping solution suitable for reuse can be obtained. In addition, according to the present invention, in the conventional resist stripping waste recycling method, resist stripping that has been increased to a certain metal and / or ionic impurity concentration and / or a certain moisture content by repeated recycling and reuse. While it is necessary to replace the entire amount of waste liquid after recycling by recycling or replace a certain amount with a new resist stripping solution, at least the frequency of such total amount replacement or constant amount replacement can be reduced.

  Furthermore, the membrane separation process using a membrane separation treatment device such as an NF membrane separation treatment device is performed in addition to the ion exchange treatment step and the water removal treatment step (which may be used as both steps), and concentration adjustment is performed as necessary. By adjusting the concentration of alkanolamine and organic solvent in the tank, it is possible to prepare a high-quality recycled resist stripper that is almost equivalent to the original (new) resist stripper. The resist stripping solution can be regenerated and reused from the waste solution.

  Furthermore, in the present invention, when at least a cation exchange resin and / or a chelate resin is used in the ion exchange treatment apparatus and brought into contact with the resist stripping waste liquid or a processing liquid derived therefrom, metals or cations in the regenerated resist stripping liquid are used. Since the concentration of the chemicals is always kept at a low level, additional amounts of additives such as corrosion inhibitors, chelating agents and organic acids, and sometimes even initial amounts can be reduced, and in some cases The advantage is that no additional addition of additives is required.

  Next, the best mode for carrying out the invention will be described with reference to the drawings, but the present invention is not limited thereto.

  FIG. 1 is a flowchart showing an example of a resist stripping waste liquid recycling treatment apparatus of the present invention that can carry out the method of the present invention. The resist on the substrate such as a wafer or a glass substrate is dissolved and peeled with a new or regenerated resist stripping solution sent from the concentration adjusting tank 25 by the resist stripping apparatus 1. The resist stripping waste liquid generated from this is temporarily stored in the resist stripping waste liquid storage tank 3 through the line 2. A part of the resist stripping waste liquid stored in the resist stripping waste liquid storage tank 3 may be discharged (drained) out of the system through the line 4 in some cases. When it is considered unsuitable for regeneration, the entire amount may be drained out of the system. The pump 7 is driven, and the resist stripping waste liquid is sent from the resist stripping waste liquid storage tank 3 to the concentrated liquid tank 8 through the line 6 and merged with the concentrated liquid returned from the NF membrane separation processing apparatus 11. With the valves 13 and 24 opened, the flow rate adjusting pump 10 is driven, and the mixture of the resist stripping waste liquid and the concentrated liquid is sent to the NF membrane separation processing apparatus 11 through the line 9 to obtain the concentrated liquid and the permeated liquid. The obtained concentrated liquid is returned to the concentrated liquid tank 8 through the line 12 and circulated. At this time, the flow rate of the concentrated liquid returned by the flow meter 14 is monitored.

  The obtained permeate is sent to the ion exchange treatment device 21 through the line 20, where anions such as residual resist, metals such as Na, K, Ca, Al, Fe, and cations are removed. [When dry ion exchange resin is used, moisture is also removed and functions as an ion exchange and moisture removal treatment device, and a moisture removal treatment using a moisture remover or a degassing membrane instead of the ion exchange treatment device] In some cases, the apparatus may be arranged, or the moisture removal treatment apparatus and the ion exchange treatment apparatus may be connected in series (the order may be in this order or the reverse order). The obtained ion exchange treatment liquid is sent to the concentration adjustment tank 25 through the line 23 and the flow meter 22. The flow meter 22 may be disposed on the line 20 between the NF membrane separation processing apparatus 11 and the ion exchange processing apparatus 21 instead of being installed at the subsequent stage of the ion exchange processing apparatus 21 as shown in the figure. The flow rate of the ion exchange treatment liquid obtained from the permeate is monitored by the flow meter 22 and is used for managing the operation of the NF membrane separation processing apparatus 11 (particularly the permeate recovery rate) together with the flow rate value of the flow meter 14. The concentration adjustment tank 25 is provided with a drain line 26 and a valve 27 to adjust the amount of liquid in the concentration adjustment tank 25 and the like. A filtration membrane treatment device (not shown) such as a microfiltration membrane treatment device for removing fine particles may be provided in the line immediately before or after the concentration adjusting tank 25.

  The pump 31 is driven, alkanolamine is added to the concentration adjusting tank 25 from the alkanolamine storage tank 32 through the lines 33 and 30, and a control valve 34 is used to adjust the amount of addition. Similarly, an organic solvent is added to the concentration adjusting tank 25 from the organic solvent storage tank 35 through the line 36 and the line 30, and a control valve 37 is used to adjust the addition amount.

  The regenerated resist stripping solution whose concentration is adjusted by driving the pump 40 is sent to the resist stripping apparatus 1 through the line 41. The flow rate of the recycled resist stripping solution to be sent is adjusted by the control valve 42. The recycled resist stripping solution is not always supplied to the resist stripping apparatus 1. When not supplied, the valve 42 is closed, and the recycled resist stripping solution is returned to the concentration adjusting tank 25 through the line 49 branched from the line 41 and circulated. The supply to the sampling line 43 branched from the line 41 is not stopped. Through this sampling line 43, a small amount of the regenerated resist stripping solution is supplied to a first absorptiometer 44 as an alkanolamine concentration detector and a second absorptiometer 45 as an organic solvent concentration detector, and then to a line 41 through a line 46. return. However, the first absorptiometer 44 and the second absorptiometer 45 may be installed directly on the main line. The concentration value data of the alkanolamine and the organic solvent obtained by the first absorptiometer 44 and the second absorptiometer 45 are transmitted to the controller 47, and the controller 47 adjusts the opening degree of the control valves 34 and 37, Adjust alkanolamine addition amount and organic solvent addition amount. As described above, as the alkanolamine concentration detector and the organic solvent concentration detector, it is preferable to use an absorptiometer as a simple measuring device as described above. However, as long as the concentration of these components can be detected, the absorptiometer It is not limited. Although not shown, if necessary, an additive supply device consisting of a concentration detector for an additive such as a corrosion inhibitor, a chelating agent, and an organic acid, a storage tank, a line, and a valve may be provided in the same manner. Good.

  In the resist stripping waste liquid regeneration processing apparatus of FIG. 1, as a preferred mode, the permeate from the NF membrane separation processing apparatus 11 (at least the first stage permeate if the NF membrane separation processing apparatus 11 is multi-stage) is passed through the valve 51. A line 50 that opens and drains outside the system, and a return line 52 that opens the valve 53 and returns to the resist separation waste liquid storage tank 3 in the front stage of the NF membrane separation processing apparatus 11 in the case of FIG. When the amount of resist stripping solution used decreases due to a decrease in the operation rate of the production line, etc., the amount of resist stripping waste fluid sent from the resist stripping device 1 decreases, and the processing capacity of the resist stripping waste liquid recycling processing device is sent out. Exceeds the amount of resist stripping waste liquid. At this time, the resist stripping waste liquid recycling apparatus is in an on / off operation state in which operation / standby is repeated. For example, in such an on / off operation state, during the standby of the NF membrane separation processing apparatus 11, impurities such as resist in the resist stripping waste liquid move to the permeate side of the NF membrane separation processing apparatus 11 due to diffusion, and restart initial stage In addition, the concentration of impurities in the permeate increases, causing problems such as poor quality of the regenerated resist stripping solution and an increase in the load of the ion exchange treatment apparatus at the subsequent stage. In order to avoid such a problem, the drain line 50 and the return line 52 may be provided only on one side, but it is preferable to provide both on the point that all situations can be handled. Also, the same problem can be avoided when pausing due to maintenance or device abnormality. When the NF membrane separation processing apparatus 11 is restarted after being stopped for a predetermined time or longer, the valve 51 or the valve 53 is opened, the valve 24 is closed, and a permeate containing a high concentration of impurities is passed through the line 50 for a predetermined amount or a predetermined time. In order to drain to the outside of the system or to return to the previous stage of the NF membrane separation processing apparatus 11 through the line 52, in the case of FIG. 1, to the resist stripping waste liquid storage tank 3, a timer or the like is used. Use, preferably a control device. Note that what has been described above is not limited to the NF membrane separation processing apparatus, and the same applies when other membrane separation processing apparatuses are used.

  Further, in the resist stripping waste liquid recycling apparatus of FIG. 1, as a preferred embodiment, a resist stripping waste liquid component concentration detector from the resist stripping waste liquid storage tank 3, in particular, a third absorptiometer 55 as a resist concentration detector, and A component concentration detector of the permeate from the NF membrane separation processing apparatus 11, particularly a fourth absorptiometer 56 as a resist concentration detector is provided via sampling lines 54 and 57 (however, a resist stripping waste liquid storage tank The component concentration detector of the resist stripping waste liquid from No. 3 may be omitted, and the component concentration detector may be installed directly on the main line without using the sampling line). The liquid used for concentration detection may be returned to the resist stripping waste liquid storage tank 3 through the sampling lines 54 and 57, or drained, but it is not necessary to provide both means for returning and draining as shown in the figure. Usually, only one means is required. Instead of a resist concentration detector, an alkanolamine concentration detector, an organic solvent concentration detector, or two or more of these three types of detectors may be used, but the resist concentration detector is usually the most effective and only Is enough. The processing performance of the NF film deteriorates in the medium to long term, and the quality of the permeated liquid (concentration of each component, particularly the resist concentration) changes. Since the liquid quality change of the permeate also affects the quality of the regenerated resist stripping solution, it is necessary to periodically replace the NF membrane module (or element) before the deterioration progresses. ) The degree of performance deterioration of the NF membrane module (or element) varies depending on the individuality of each product, operation history, resist stripping waste liquid composition, etc., so replacement at the optimal time is extremely difficult and the replacement time is delayed The quality of the regenerated resist stripping solution may deteriorate and affect the product yield. On the other hand, when the replacement is performed early with a margin, there is a problem that the cost (NF membrane purchase cost, replacement work cost, etc.) associated with the replacement of the NF membrane module (or element) increases. Further, at the time of replacement work, it is necessary to temporarily stop the resist stripping waste liquid regeneration processing apparatus for performing the NF film processing, and depending on the case, it is necessary to stop the developing device and the production line. In order to solve such problems, a third absorptiometer 55 and a fourth absorptiometer 56 are provided. That is, when the NF film deteriorates, its resist removal rate changes, and usually decreases, so that the resist concentration in the permeate changes (the concentration of other components may also change) and usually increases. It becomes a trend. Therefore, the range of the liquid quality management reference value is determined in advance, and the NF membrane module (or element) is replaced when the measured resist concentration value deviates from the range. In addition, since the third absorptiometer 55 is also provided in front of the NF membrane separation processing apparatus 11, the measured value and the measured value of the permeate are compared to determine the replacement time of the NF membrane module (or element). Judge more accurately. When the NF membrane separation processing apparatus is multistage, it is needless to say that it is desirable to have a configuration that can measure the component concentration of the permeate in each stage. Note that what has been described above is not limited to the NF membrane separation processing apparatus, and the same applies when other membrane separation processing apparatuses are used.

  The NF membrane separation processing apparatus may be, for example, a single-stage system that circulates the concentrate as described above with reference to FIG. As a multistage NF membrane separation processing apparatus, three modes will be described below with reference to the drawings. Here, the liquid to be treated is a resist stripping waste liquid or a processing liquid derived therefrom, and is usually a resist stripping waste liquid, but this is abbreviated as “raw waste liquid”.

<1> Two-stage system for high recovery rate (see Fig. 2)
From the raw waste liquid tank 61 containing the raw waste liquid, the liquid is fed through the safety filter 63 by the pump 62 and further to the first nanofilter 65 by the pump 64. And a permeate mainly containing alkanolamine and an organic solvent (hereinafter referred to as “NF permeate”). The NF concentrate is sent to the second nanofilter 67 by the pump 66, while the NF permeate is sent to the NF permeate tank 68.

  In the second nanofilter 67, the NF concentrate is subjected to NF membrane separation treatment, and the alkanolamine and the organic solvent in the NF concentrate are further recovered on the NF permeate side, and this NF permeate is passed through the NF permeate line 69. It may be returned via and mixed in the raw waste liquid. On the other hand, the NF concentrate obtained from the second nanofilter 67 is discharged out of the system as a waste liquid through the drain line 70, for example. When the resist concentration of the NF permeate obtained from the second nanofilter 67 is relatively low, at least a part thereof is sent to the NF permeate tank 68 through the NF permeate line 71 and obtained from the first nanofilter 65. You may make it merge with NF permeation | transmission liquid. Whether the NF permeate obtained from the second nanofilter 67 is returned to the raw waste liquid or at least part of the NF permeate is combined with the NF permeate obtained from the first nanofilter 65 depends on the purity and the like. And the valve 73. The NF permeate in the NF permeate tank 68 is sent to an ion exchange processing device not shown. The NF permeate tank 68 may be omitted.

<2> Two-stage system for high purity (see Fig. 3)
The raw waste liquid tank 81 containing the raw waste liquid is passed through the safety filter 83 by the pump 82, and further sent to the first nanofilter 85 by the pump 84, where the NF concentrated liquid and the alkanol in which impurities such as resist are concentrated by the NF film. Separated into an NF permeate mainly containing an amine and an organic solvent. For example, the NF concentrate is discharged out of the system as a waste liquid through a drain line 86. On the other hand, the NF permeate is sent to the second nanofilter 88 by the pump 87, where it is further purified mainly containing NF concentrate, alkanolamine, and organic solvent in which impurities such as residual resist are concentrated by the NF film. The NF permeate is separated. Since this NF concentrate is relatively clean, it is returned via the NF concentrate line 89 and mixed into the raw waste liquid. On the other hand, the NF permeate obtained from the second nanofilter 88 is sent to the NF permeate tank 90, and then sent to an ion exchange processing apparatus not shown. The NF permeate tank 90 may be omitted.

<3> Combination method of the above two methods (see FIG. 4)
Raw waste tank 91, pump 92, safety filter 93, pump 94, first nanofilter 95, pump 96, second nanofilter 97, NF permeate lines 98 and 99, valves 100 and 101, and drain line 102 are <1> substantially the same system as the two-stage system (FIG. 2). In addition, the raw waste liquid tank 91, the pump 92, the safety filter 93, the pump 94, the first nanofilter 95, the pump 103, the third nanofilter 104, the NF concentrated liquid line 105, and the NF permeated liquid tank 106 are the above-mentioned <2>. A system substantially similar to the two-stage system (FIG. 3) is configured. However, instead of discharging the NF concentrate obtained from the first nanofilter 85 through the drain line 86 in FIG. 3 to the outside of the system, the NF concentrate obtained from the first nanofilter 95 in FIG. 4, instead of the NF concentrate line 89 in FIG. 3, the NF concentrate obtained from the third nanofilter 104 branches to the NF concentrate lines 105 and 107 in FIG. 4. It is configured such that it can be combined with the raw waste liquid through the line 105 or can be combined with the NF concentrated liquid obtained from the first nanofilter via the NF concentrated liquid line 107 and sent to the second nanofilter 97. The systems in both figures are different. Whether the NF concentrate obtained from the third nanofilter 104 is returned to the raw waste liquid or at least part of the NF concentrate is joined with the NF concentrate obtained from the first nanofilter 95 is determined by considering the purity and the like. And valve 109. The NF permeate in the NF permeate tank 106 is sent to an ion exchange processing apparatus not shown. The NF permeate tank 106 may be omitted.

  In such a multi-stage system, of course, each two-stage system of <1> or <2> can be configured as a system of three or more stages.

  EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited to an Example.

  The test was performed using the resist stripping waste liquid discharged from the LCD manufacturing process. The properties of the resist stripping waste liquid were as follows: resist = 524 ppm, Na = 1900 ppb, Al = 2430 ppb, Fe = 93 ppb, moisture = 4 wt%. In this example, resist was quantified by absorptiometry, Na, Al, and Fe were quantified by atomic absorption, and moisture was quantified using a Karl Fischer moisture meter.

NTR-7450 (4-inch module) manufactured by Nitto Denko Corporation was used as the NF membrane, and the above resist stripping waste liquid was subjected to membrane separation treatment at an operating filtration pressure = 10 kgf / cm ² and a permeate recovery rate = 33%. Got.

  Dry strong basic anion exchange resin Amberlyst B20-HG · DRY (water content: 10% by weight) and dry strong acid cation exchange resin Amberlyst 15JS-HG · DRY (water content: 0.5% by weight) Each was passed through another column packed in this order under the condition of SV = 5 to obtain an ion exchange treatment solution. Table 1 shows changes in liquid properties.

  The NF membrane separation treatment is quite effective for resist removal, but is insufficient for removing metals such as Na, Al, Fe and the like, and it is impossible to remove moisture. You can see from the data. It can be seen that when the NF permeate is further subjected to ion exchange treatment, the resist, metals, and moisture are removed extremely effectively.

  According to the present invention, it is possible to obtain a high-quality recycled resist stripping solution from the resist stripping waste solution, and at least extend the life of the recycling and reuse, and supply the main components and additives of the new resist stripping solution sufficiently. A method and apparatus for regenerating a resist stripping waste liquid that can be reduced to a low level is provided. Therefore, the reclaimed resist stripping liquid obtained is a flat panel display such as a semiconductor device, a liquid crystal display (LCD) or a plasma display panel (PDP), It can be reused as a resist stripping solution in a photolithography process in the production of electronic components such as printed boards.

FIG. 1 is a flowchart showing an example of a resist stripping waste liquid recycling treatment apparatus of the present invention that can carry out the method of the present invention. FIG. 2 is a flowchart showing an example of a two-stage NF membrane separation processing apparatus that may be used in the present invention. FIG. 3 is a flowchart showing another example of a two-stage NF membrane separation processing apparatus that may be used in the present invention. FIG. 4 is a flowchart showing another example of a multistage NF membrane separation treatment apparatus that may be used in the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Resist peeling apparatus 11 NF membrane separation processing apparatus 21 Ion exchange processing apparatus (There may be an ion exchange and water removal processing apparatus etc.)
25 Concentration adjustment tank

Claims (10)

  In the process of regenerating a resist stripping waste liquid mainly containing a resist, an alkanolamine and an organic solvent to obtain a recycled resist stripping liquid, the resist stripping liquid or a processing liquid derived from the resist stripping liquid is brought into contact with an ion exchange resin to form a metal. The moisture content is reduced by bringing an ion exchange treatment step to remove the ionic impurities and / or ionic impurities, and contacting the resist stripping waste liquid or the processing liquid derived from the resist stripping waste liquid with a moisture removing agent and / or a degassing membrane. A method for regenerating a resist stripping waste liquid, comprising one or both of the steps of removing moisture.   2. The resist stripping waste liquid according to claim 1, wherein the ion exchange resin is an anion exchange resin and / or a cation exchange resin and / or a chelate resin of at least one of a hydrogen ion type and an alkanolamine type. Playback processing method.   3. The method for recycling a resist stripping waste liquid according to claim 1, wherein the ion exchange resin is a dry ion exchange resin having a water content of 30% by weight or less.   It further includes a membrane separation treatment step for obtaining a permeate mainly containing an alkanolamine and an organic solvent that can be a treatment liquid derived from the resist stripping waste liquid together with the concentrate obtained by concentrating the resist by the membrane separation treatment apparatus. A method for recycling a resist stripping waste liquid according to any one of claims 1 to 3.   5. The method according to claim 1, further comprising a step of adjusting concentrations of the alkanolamine and the organic solvent in the treatment liquid obtained through at least the ion exchange treatment step and / or the water removal treatment step. Process for recycling resist stripping waste liquid.   An apparatus for regenerating a resist stripping waste liquid mainly containing a resist, an alkanolamine, and an organic solvent to obtain a recycled resist stripping liquid, wherein the resist stripping waste liquid or a processing liquid derived from the resist stripping waste liquid is brought into contact with an ion exchange resin. The moisture content of an ion exchange treatment device that removes metals and / or ionic impurities by contact with a moisture removal agent and / or a degassing membrane with a resist removal waste solution or a treatment solution derived from a resist removal waste solution A device for regenerating a resist stripping waste liquid, comprising one or both of a water removal processing device for reducing water content.   7. A membrane separation processing apparatus for obtaining a permeate mainly containing an alkanolamine and an organic solvent that can be a processing liquid derived from the resist stripping waste liquid together with the concentrated resist concentrate. The resist stripping waste liquid recycling treatment apparatus described.   A concentration adjustment tank for storing a treatment liquid obtained through at least an ion exchange treatment apparatus and / or a water removal treatment apparatus and adjusting the concentrations of alkanolamine and organic solvent in the treatment liquid, and alkanolamine in the concentration adjustment tank The apparatus for regenerating a resist stripping waste liquid according to claim 6 or 7, further comprising an alkanolamine supply means for supplying the organic solvent and an organic solvent supply means for supplying an organic solvent to the concentration adjusting tank.   A line for draining the permeate from the membrane separation processing apparatus to the outside of the system and / or a line for returning the permeate to the front stage of the membrane separation processing apparatus when the membrane separation processing apparatus has multiple stages. The resist stripping waste liquid recycling apparatus according to claim 7 or 8, characterized in that is provided.   10. The resist stripping waste liquid regeneration processing apparatus according to claim 7, further comprising a component concentration detector for the permeated liquid from the membrane separation processing apparatus.

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