JP4085987B2 - Recycle processing method of photoresist development waste liquid - Google Patents

Description

  The present invention relates to a photoresist generated in a manufacturing process of an electronic component such as a semiconductor device, a liquid crystal display (LCD), a printed board, and the like, and a method for recycling a photoresist developing waste liquid containing tetraalkylammonium ions.

  To manufacture electronic devices such as semiconductor devices, liquid crystal displays, and printed circuit boards, a negative or positive photoresist film is formed on a substrate such as a wafer, irradiated with light through a pattern mask, and then developed. Unnecessary photoresist is dissolved in a solution and developed, and after further processing such as etching, the insoluble photoresist film on the substrate must be peeled off. There are two types of photoresists: a positive type in which the exposed part is soluble and a negative type in which the exposed part is insoluble. Alkaline developer is the mainstream as the developer for positive type photoresist, and as the developer for negative type photoresist, Organic solvent-based developers are the mainstream, but some use alkaline developers.

As the alkali developer, an aqueous solution of tetraalkylammonium hydroxide (tetraalkylammonium hydroxide) is usually used. Therefore, the waste liquid discharged from the development step (referred to as “photoresist development waste liquid” or “photoresist alkali development waste liquid”) usually contains dissolved photoresist and tetraalkylammonium ions. Here, as is apparent from the above, the tetraalkylammonium ion is usually a hydroxide ion (OH ⁻ ) as a counter ion, but the waste liquid (waste water) varies depending on the factory. It does not know what is mixed in, and may be mixed with other waste water depending on the case, so that it may be in the form of a salt with other types of ions as counter ions. Therefore, in the general description in the present specification, the counter ion is not specified, but the concept of “ion” is used. However, since the tetraalkylammonium ion in the waste liquid is usually present as tetraalkylammonium hydroxide as described above, the present invention will be described mainly.

  Conventionally, as a method for treating such photoresist and a photoresist developing waste solution containing tetraalkylammonium ions, a method of collecting the whole amount by a supplier, a method of concentrating by an evaporation method or a reverse osmosis membrane method and a method of disposal (incineration or supplier taking) There is a method of biodegradation treatment with activated sludge and release. In addition, for the concentrated waste liquid obtained as described above or the concentrated waste liquid originally having a high concentration of tetraalkylammonium ions, tetraalkylammonium ions are preferably converted into a hydroxide form by electrodialysis or electrolysis. Attempts have been made to concentrate and recover it in the form of hydroxide) and reuse it.

In the method of concentrating by the evaporation method or the reverse osmosis membrane method, both the alkali-soluble photoresist and the tetraalkylammonium ions are concentrated, so that the waste liquid after treatment must be discarded. The method of biodegradation treatment with activated sludge has a poor biodegradability of tetraalkylammonium ions, and when other organic components are mixed in the waste liquid, the growth of microorganisms that decompose these other organic components is increased. Since the growth of microorganisms that decompose tetraalkylammonium ions becomes inactive and the biodegradability is further deteriorated, only low-concentration waste liquid can be treated, and a large-scale treatment facility is required. . Further, a method of concentrating and recovering tetraalkylammonium ions, preferably in the form of hydroxide, by electrodialysis or electrolysis is the best in terms of pollution control and effective use of resources. High purity is required when reused as a photoresist alkaline developer for the manufacture of electronic components such as liquid crystal displays and printed circuit boards. In this respect, a small amount of photoresist, Na ⁺ , K ⁺ , Ca ^2+, etc. It has been a problem that impurities such as cations (particularly Na ⁺ ) remain.

  Accordingly, an object of the present invention is to solve the above-mentioned disadvantages of the conventional processing method for a photoresist developing waste solution containing photoresist and tetraalkylammonium ions, and to provide a simple and effective method for recycling the photoresist developing waste solution. Is to provide.

The present invention, photoresist when processing a development waste, Te tiger alkylammonium ion form (TAA form) cation exchange resin or an anion exchange resin及beauty T AA type, containing mainly photoresist and tetraalkylammonium ions A photoresist comprising at least a step of adsorbing and removing impurities by contacting the cation exchange resin, and a step of concentrating and separating the treatment liquid obtained through the step by at least one of electrodialysis and electrolysis It is an object of the present invention to provide a method for regenerating a photoresist developing waste solution, which comprises reclaiming and recovering a high purity tetraalkylammonium hydroxide solution that can be reused as a photoresist developer from the developing waste solution.

  In the method of the present invention, a step of adsorbing and removing impurities is carried out by directly contacting a photoresist developing waste solution containing photoresist and tetraalkylammonium ions (hereinafter sometimes abbreviated as “developing waste solution”) with an ion exchange resin. Although it is easy to process by the electrodialysis and / or electrolysis concentration step, if necessary, the development waste solution or its concentrated solution (concentration by evaporation and / or reverse osmosis membrane treatment described later) is previously performed before these steps. Liquid) and solid-liquid separation to remove the photoresist to some extent, to obtain a neutralization treatment liquid mainly containing tetraalkylammonium ions having a reduced amount of photoresist, and passing through the above-described steps. This may be particularly preferable from the viewpoint of the exchange capacity of the anion exchange resin. However, in this case, in order to convert the tetraalkylammonium ion into a hydroxide (OH) form, an electrolysis process is usually required.

  Note that a developing waste solution containing tetraalkylammonium hydroxide and a photoresist usually exhibits an alkaline pH of 12 to 14, and the photoresist is dissolved in the alkaline solution. The present invention can be applied to such an alkaline developing waste liquid as it is. Alkali-soluble photoresists have carboxyl groups and the like, and these groups become tetraalkylammonium salts during development and the photoresist dissolves in the developer. Below, preferably at a pH of 8 or less (which may be acidic), it becomes a carboxyl group again, and most of the photoresist becomes insoluble, so that most of the photoresist can be removed by solid-liquid separation methods such as centrifugation and filtration. Become. In the present specification, a processing solution obtained by neutralizing development waste solution and the like and removing the photoresist to some extent by a solid-liquid separation method such as centrifugation or filtration is referred to as a “neutralization processing solution”.

Cations such as Na ⁺ , K ⁺ , and Ca ²⁺ originally present in the developer waste liquid are, for example, Na ⁺ is 10 ppb or less in the tetramethylammonium hydroxide product as the developer, and in the developer waste liquid after use. In some cases, 100 ppb or more may be present, and anions such as Cl ⁻ , NO ₃ ⁻ , SO ₄ ²⁻ , HCO ₃ ⁻ , and CO ₃ ²⁻ may also be present.

  When the anion exchange resin is in the OH form, tetraalkylammonium ions are advantageously present in the form of tetraalkylammonium hydroxide in the anion exchange treatment solution. Further, when it is brought into contact with a cation exchange resin, the cation component is also adsorbed and removed.

  Whether to use only a cation exchange resin or both an anion exchange resin and a cation exchange resin as the ion exchange resin, the solution in relation to the application of the solution of the regenerated tetraalkylammonium hydroxide What is necessary is just to decide by the tolerance of various impurities, such as a photoresist, anions, and cations remaining in it. However, for example, as described above, in order to use a regenerated tetraalkylammonium hydroxide solution as a developer for the production of electronic components such as semiconductor devices, liquid crystal displays, and printed circuit boards, both anion exchange resins and cation exchange resins are used. It is desirable to use

As the anion exchange resin, an anion exchange resin such as a styrene type or an acrylic type such as fibrous or granular is preferable in terms of processing efficiency, or a plurality of these types are mixed or laminated at an arbitrary ratio. However, as will be described later, a styrene-based anion exchange resin is particularly preferable from the viewpoint of photoresist removal efficiency. The acrylic anion exchange resin is obtained by crosslinking (meth) acrylic acid or esters thereof with divinylbenzene (DVB) or the like. In addition, strong basic anion exchange resins are preferable in terms of photoresist removal efficiency, but weak basic anion exchange resins also have a photoresist removal effect, particularly on the neutral or acidic side, and these multiple types can be arbitrarily selected. They may be mixed or laminated at a ratio of Further, the counter ion of the anion exchange resin, OH ^- but Cl ^- may be a such, Cl ^- pair when using an anion exchange resin Cl shape such that the counter ion and the like tetraalkylammonium ions ions of at least one it means that the change to such, OH ^{- -} part is Cl preferable to use OH Katachikage ion exchange resin to counterion. When a weakly basic anion exchange resin is used on the neutral or acidic side, or when an anion exchange resin such as Cl-type using Cl 2 ⁻ or the like as a counter ion is used, tetraalkylammonium ions are added to water. In order to obtain a tetraalkylammonium oxide form, electrolysis may be performed later.

  As the cation exchange resin, a cation exchange resin such as a styrene type or an acrylic type such as fibrous or granular is preferable from the viewpoint of processing efficiency, and either a weak acid cation exchange resin or a strong acid cation exchange resin may be used. Alternatively, a plurality of these types may be mixed or laminated at an arbitrary ratio.

Cation exchange resins are typically commercially available in hydrogen ion form (H form) or sodium ion form (Na form), and such cation exchange resins (preferably H form) can be used prior to their use. By using the tetraalkylammonium form (TAA form) in advance, tetraalkylammonium hydroxide is adsorbed on the cation exchange resin at the beginning of the passage through the cation exchange resin, and its concentration in the treatment liquid decreases. It is possible to prevent the occurrence of the phenomenon. That is, the cation exchange resin, Ru used as Te tiger alkyl ammonium form (TAA form). However, it may not be a complete TAA type cation exchange resin, but may be partially H type, and H type cation exchange resin and TAA type cation exchange resin may be mixed or laminated at any ratio. May be used.

  Needless to say, it is preferable to use an ion exchange resin (cation exchange resin, or anion exchange resin and cation exchange resin) that has been sufficiently washed with ultrapure water so that there is no eluate in use.

  When both an anion exchange resin and a cation exchange resin are used as an ion exchange resin, they may be used as a mixed ion exchange resin in which an anion exchange resin and a cation exchange resin are mixed and packed in a column or tower. The anion exchange resin is preferably packed in a column or a column on the upstream side and the cation exchange resin is used on the downstream side. However, when only a small amount of photoresist originally exists in the waste liquid, a cation exchange resin may be disposed on the upstream side and an anion exchange resin may be disposed on the downstream side. Alternatively, an anion exchange resin can be packed in an upstream column or tower, and a cation exchange resin can be packed in a downstream column or tower and used separately. As a result, the exchange capacity can be reduced, or only the deteriorated ion exchange resin can be easily replaced, which is convenient.

  The advantage of placing an anion exchange resin on the upstream side and a cation exchange resin on the downstream side is that the trace amount of amines can be eluted from the anion exchange resin, so the cation exchange resin on the downstream side. It is that this eluting amine can be capture | acquired by arrange | positioning. In addition, since the photoresist, which is a polymer substance, is adsorbed on the surface of the cation exchange resin and may reduce the activity of the cation exchange, an anion exchange resin is disposed on the upstream side in advance. It is advantageous to remove the photoresist sufficiently.

  Further, at least before the electrodialysis and / or electrolysis step, a step of further concentrating the photoresist developing waste solution or its processing solution (neutralization processing and / or ion exchange processing solution) by evaporation and / or reverse osmosis membrane treatment. Preferably included. Such evaporation and / or reverse osmosis membrane treatment steps may be performed before or after the neutralization treatment step and / or the ion exchange treatment step or at any stage between the two.

  Advantages of carrying out this evaporation and / or reverse osmosis membrane treatment process include improvement in current efficiency in electrodialysis and electrolysis, miniaturization of electrodialysis equipment and / or electrolysis equipment and reduction in running cost due to a decrease in the amount of liquid to be treated. Reduction, applied voltage reduction, and tetraalkylammonium ion recovery rate.

  As described above, evaporation and reverse osmosis membrane treatment also concentrate impurities such as photoresist in the concentrated solution, but these concentrated impurities are preferably ion exchange treatment at least after the evaporation or reverse osmosis membrane treatment. And at least by electrodialysis and / or electrolysis, there is no particular problem.

  Note that condensed water for evaporation and permeated water for reverse osmosis membrane treatment contain almost no photoresist or tetraalkylammonium ions, and can be used as process water or the like. In the case of the reverse osmosis membrane treatment, it is preferable to carry out the treatment at a pH of 9 to 12 from the viewpoint of reducing the deterioration of the reverse osmosis membrane.

  Comparing evaporation and reverse osmosis membrane treatment, the former has the advantage that the running cost is high but the concentration factor can be easily increased, and the latter has the advantage that the running cost is low, but the concentration factor has a limit, and the concentration is deliberate. In order to increase the magnification, a large-sized high-pressure pump for overcoming the osmotic pressure is necessary, and the upper limit of the tetraalkylammonium ion concentration of the practical concentrated liquid is about several percent. Therefore, whether to select evaporation or reverse osmosis membrane treatment or a combination thereof may be determined from characteristics such as tetraalkylammonium ion concentration of the photoresist developing waste solution.

  Further, a membrane processing apparatus may be installed at or near the last stage, and in this case, fine particles originally present in the developing waste liquid can be removed, and from an electrodialysis apparatus and / or an electrolysis apparatus, a pump, an ion exchange resin, etc. Even if fine particles are mixed in, it is preferable because it can be surely removed.

  Examples of the membrane treatment apparatus include a membrane treatment apparatus using a polypropylene (PP) filter or a polytetrafluoroethylene (PTFE) filter having a pore diameter of about 0.03 to 1 μm, an ultrafiltration membrane apparatus, and the like. It is possible to select and use an appropriate film processing apparatus in accordance with the purpose.

  The treatment liquid as a high-purity tetraalkylammonium hydroxide solution thus obtained may be further concentrated (electrodialysis, electrolysis) by a method such as evaporation, reverse osmosis, or a combination thereof. In this case, when processing is performed by the above-described film processing apparatus, the order of each processing operation can be any order. However, in view of the purpose of processing by the film processing apparatus is removal of fine particles, The processing by the processing device is preferably performed at the last stage.

  When the tetraalkylammonium ions are concentrated by electrodialysis or electrolysis after the contact with the ion exchange resin, at least one of electrodialysis and electrolysis may be performed by a circulation system or a multistage system. The tetraalkylammonium ion concentration and purity of the liquid can be increased.

  Tetraalkylammonium ions in photoresist alkaline developer wastewater are tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide as alkalis used in photoresist developers used in the manufacture of various electronic components. , Tetrabutylammonium hydroxide, methyltriethylammonium hydroxide, trimethylethylammonium hydroxide, dimethyldiethylammonium hydroxide, trimethyl (2-hydroxyethyl) ammonium hydroxide, triethyl (2-hydroxyethyl) ammonium hydroxide, dimethyldihydroxide (2-hydroxyethyl) ammonium, diethyldi (2-hydroxyethyl) ammonium hydroxide, methyltri (2-hydroxyethyl) ammonium hydroxide, hydroxy acid Ethyltri (2-hydroxyethyl) ammonium, tetra (2-hydroxyethyl) ammonium and the like (in particular, the former two) derived from tetraalkyl ammonium hydroxide.

As described above, the counter ion of the tetraalkylammonium ion in the development waste liquid is usually a hydroxide ion (OH ⁻ ). However, depending on the factory, and when neutralization is performed, the counter ion of fluoride ion (OH ⁻ ) Inorganic anions such as fluoride ion, chloride ion, bromide ion, carbonate ion, bicarbonate ion, sulfate ion, hydrogen sulfate ion, nitrate ion, phosphate ion, hydrogen phosphate ion, dihydrogen phosphate ion, formate ion, acetic acid In general, at least one selected from organic anions such as ions and oxalate ions is at least a part of a counter ion of a tetraalkylammonium ion. In particular, carbonate ions and hydrogen carbonate ions are often present in a small amount as carbon dioxide in the air dissolves in the developing waste solution. In the concentrated solution obtained by electrolysis, hydroxide ions are usually counter ions of tetraalkylammonium ions, which hinders reuse of the resulting tetraalkylammonium hydroxide solution as a photoresist alkali developer. When the amount of the above counter ions other than hydroxide ions is so large that at least the step of electrolysis is included in the method of the present invention.

  In ordinary photoresist development waste liquid, the photoresist is dissolved as an anionic polymer due to carboxyl groups and the like, while tetraalkylammonium hydroxide is a cation tetraalkylammonium ion and anion. Dissociated into hydroxide ions.

  By contacting such waste liquid with the anion exchange resin, the photoresist in the waste liquid can be adsorbed on the anion exchange resin and removed.

  Alkali developed photoresists are mainly composed of a novolak resin as a base resin, and this novolak resin has a large number of benzene rings. When an anion exchange resin having a styrene-based benzene ring is used as an anion exchange resin, it is highly selective due to the affinity (hydrophobic) interaction between benzene rings in addition to electrostatic interaction. It is considered that the photoresist can be removed.

  If the photoresist developer waste solution is contact-treated with an anion exchange resin as described above before concentration by electrodialysis and / or electrolysis, the photoresist removal is easy because the concentration of tetraalkylammonium hydroxide in the developer waste solution is low. Done. Therefore, a tetraalkylammonium hydroxide solution containing almost no photoresist is concentrated by electrodialysis and / or electrolysis, so that when the cation impurities are removed by contacting with a cation exchange resin, the resulting treatment solution has a high purity. Can be recycled and reused as a developer.

  For development waste liquid containing a high concentration of photoresist, from the viewpoint of the ion exchange capacity of the anion exchange resin, neutralization is performed as a pretreatment to insolubilize the photoresist, and solid liquid such as centrifugation or filtration After separation and removal by the separation method, it is advantageous to remove the residual photoresist by contacting the anion exchange resin as described above and adsorbing the remaining photoresist on the anion exchange resin. Thus, at least a part of the tetraalkylammonium hydroxide becomes a tetraalkylammonium salt. Contact with the cation exchange resin to remove cation impurities. If the solution containing the tetraalkylammonium salt thus obtained (neutralizing solution) is concentrated by electrodialysis or electrolysis, a high-purity tetraalkylammonium salt (in the case of electrodialysis) or tetraalkylammonium hydroxide (electrolytic In the case). In the case of electrolysis, the electrodialysis can be regenerated as a tetraalkylammonium hydroxide by further electrolysis. The resulting processing solution can be regenerated and reused as a high purity developer.

The photoresist process for regeneration of waste developer of the present invention, with respect tetraalkylammonium ions containing photoresist development waste containing at least photoresist, T AA type cation exchange resin or an anion exchange resin及beauty T AA type, Impurities such as photoresist and other ionic components can be sufficiently removed by performing at least the contact step with cation exchange resin and electrodialysis and / or electrolysis step, and can be reused as a photoresist alkaline developer. A high-purity tetraalkylammonium hydroxide-containing solution can be obtained.

  If the evaporation and / or reverse osmosis membrane treatment step is performed at least before the electrodialysis and / or electrolysis step, the electrodialysis device and / or electrolysis accompanying the improvement of the current efficiency in electrodialysis and electrolysis and the reduction of the amount of the liquid to be treated. Advantages such as downsizing of the apparatus and reduction of running cost, reduction of applied voltage, and improvement of recovery rate of tetraalkylammonium ions occur, and total processing cost can be reduced.

  Examples of the best mode for carrying out the present invention as described above include the following embodiments, but it goes without saying that the present invention is not limited to these embodiments.

<1> At least one of photoresist development waste with an anion exchange resin及beauty T AA type cation exchange resin comprising the steps of contacting for adsorbing and removing impurities, electrodialysis and electrolysis treatment solution obtained by the above step And a method of regenerating and recovering a photoresist developing waste solution, comprising at least a step of regenerating and recovering a high-purity tetraalkylammonium hydroxide solution that can be reused as a photoresist developer. .

<2> photoresist development waste is neutralized, and a step of separating and removing the photoresist became insoluble, neutralized solution an anion exchange resin及beauty T AA type cation-exchange resin obtained by the above step High purity, which can be reused as a photoresist developer, comprising at least a step of adsorbing and removing impurities by contacting the substrate and a step of concentrating and separating the processing solution obtained through the above two steps by electrodialysis and electrolysis or by electrolysis A method for regenerating a photoresist developing waste solution, comprising regenerating and recovering a tetraalkylammonium hydroxide solution.

  As described above, in the methods <1> and <2> described above, it is preferable to perform the film treatment at or near the last stage. In the above methods <1> and <2>, at least before the electrodialysis and / or electrolysis step, the photoresist developing waste liquid or its processing liquid (neutralization processing and / or ion exchange processing liquid) is evaporated and / or Alternatively, as described above, it is preferable to further include a step of concentrating by a reverse osmosis membrane treatment.

As a photoresist developer, an aqueous solution having a tetramethylammonium hydroxide (hereinafter abbreviated as “TMAH”) concentration of 2.38% by weight is most commonly used. When the photoresist is developed with this developer, a development waste solution containing the photoresist and TMAH is usually generated. Cationic metal ions such as Na ⁺ , K ⁺ , Ca ²⁺ , Fe ²⁺ , Fe ³⁺ , Cu ²⁺ , and Al ³⁺ are added to the developer waste liquid due to contamination from chemicals and elution from piping materials. In general, these metal ions may adversely affect the production of electronic components. Therefore , it is treated with at least one cation exchange resin of TAA type (in this case, TMA type).

Next, the principle of electrodialysis when electrodialysis is performed in the processing method for developing waste liquid according to the present invention will be described with reference to FIG. Tetraalkylammonium ion (hereinafter abbreviated as “TAA ion”) is a hydroxide ion (OH ⁻ , hereinafter abbreviated as “OH ion”) and its counter ion is tetraalkylammonium hydroxide (hereinafter referred to as “TAAH”). A normal case in the form of "abbreviated") will be described.

As shown in FIG. 1, a cation exchange membrane (cation exchange membrane) 3 and an anion exchange membrane (anion exchange membrane) 4 are alternately arranged between the cathode 1 and the anode 2 to form a plurality of cells. ing. In the raw waste solution containing TAAH and photoresist sent to the cell (treatment liquid obtained through ion exchange resin treatment, or treatment liquid obtained through evaporation and / or reverse osmosis membrane treatment and ion exchange resin treatment) Since TAAH is dissociated into TAA ions (TAA ⁺ ) as cations and OH ions as anions, when a direct current is applied between the cathode 1 and the anode 2, the TAA ions pass through the cation exchange membrane 3. It moves to the cathode side through, but is almost blocked by the next anion exchange membrane 4, while OH ions move to the anode side through the anion exchange membrane 4, but is almost blocked by the next cation exchange membrane. Therefore, TAAH is concentrated in a certain cell, and TAAH is decreased in a cell adjacent to the cell. That is, the cell (A) having the anion exchange membrane 4 on the side facing the cathode 1 functions as a concentration cell. Here, TAAH is concentrated to become a concentrated solution, and the side on which the anion exchange membrane 4 faces the anode 2 is concentrated. The cell (B) contained in the cell functions as a desalting cell, where TAAH is reduced to a desalting solution. Since the photoresist in the raw waste liquid hardly passes through the ion exchange membrane, it passes through the concentration cell and the desalting cell as it is, and remains in the concentrated solution and the desalting solution.

  As is clear from the above description, when the raw waste liquid is passed through both the desalting cell and the concentration cell as shown in FIG. 1, the photoresist remains in the concentrated solution as it is, Since only the TAAH is concentrated on the concentration cell side and the photoresist is not concentrated, the concentration of the photoresist in the concentrated solution is almost the same as the concentration in the raw waste solution. In this respect, electrodialysis is not limited to TAAH. This is clearly different from the evaporation method and the reverse osmosis membrane method in which the photoresist is also concentrated at the same time.

  In the present invention, since the purpose is to regenerate and recover a high-purity TAAH solution that can be reused as a photoresist alkaline developer, it is preferable to obtain a concentrated solution almost free of photoresist by electrodialysis. The raw waste solution is passed through the desalting cell side, and the ultrathin pure water or low-concentration TAAH solution that does not contain photoresist [for example, a small amount of new TAAH is dissolved in the (super) pure water] It is preferable to pass an electrolyte solution such as [liquid]. However, when the raw waste liquid is also sent to the concentration cell, it is advantageous in that the amount (volume) of waste water discharged as a desalting liquid is reduced.

As the electrodialysis apparatus, those commonly used can be used, and the ion exchange membrane used for this is not particularly limited as long as it can selectively separate cations and anions, for example, Aciplex [Asahi Kasei Kogyo Co., Ltd.], Selemion [Asahi Glass Co., Ltd.], Neoceptor [Tokuyama Soda Co., Ltd.] and the like can be mentioned. Further, the characteristics of the ion exchange membrane may be general, and for example, the thickness may be 0.1 to 0.6 mm and the resistance may be about 1 to 10 Ω · cm ² .

  The structure of the electrodialyzer is not particularly limited. For example, a cation exchange membrane and an anion exchange membrane are provided with an inflow hole and an outflow hole for a liquid to be desalted and an inflow hole and an outflow hole for a liquid to be concentrated. A plurality of cells may be formed by alternately laminating a plurality of gaskets with appropriate intervals, and an electrodialysis apparatus may be configured by sandwiching both ends with a pair of electrodes.

  Here, instead of the anion exchange membrane, a neutral membrane such as polyvinyl alcohol having alkali resistance superior to that of the anion exchange membrane may be used. Neutral membranes are simply polymer membranes without ionic functional groups, but they can pass TAA ions, but their permeability is lower than that of cation exchange membranes. Thus, concentration by electrodialysis can be performed. However, when a neutral membrane is used instead of an anion exchange membrane, the current efficiency is worse than in the case of an anion exchange membrane.

  Examples of the electrodialysis process include a circulation system as shown in FIG. 2 and a multistage treatment system as shown in FIG.

  In the circulation system shown in FIG. 2, the raw waste liquid is sent from the waste liquid tank 6 containing the raw waste liquid containing TAAH and photoresist to the desalting liquid tank 7 by the pump 9, and a direct current is supplied from the desalting liquid tank 7 by the pump 10. The desalted solution sent to the desalting cell of the applied electrodialyzer 5 is returned to the desalted solution tank 7 for circulation. On the other hand, the concentrated liquid tank 8 is a raw waste liquid or a low-concentration TAAH solution that does not contain (ultra) pure water or a photoresist (for example, a liquid in which a small amount of new TAAH is dissolved in (ultra) pure water). The electrolyte solution is charged, sent to the concentration cell of the electrodialysis apparatus 5 by the pump 11, and the concentrated solution flowing out from the concentration cell is returned to the concentrated solution tank 8 and circulated. The electrical conductivity of the desalted liquid in the desalted liquid tank 7 is measured with an electric conductivity meter 12, and when the salt is desalted to a certain desalting rate, a part of the desalted liquid in the desalted liquid tank 7 is removed. The waste liquid is discharged out of the tank, and the raw waste liquid is sent from the waste liquid tank 6 into the desalted liquid tank 7 by the discharged amount. On the other hand, when the TAAH concentration in the concentrate tank 8 reaches a predetermined concentration, the concentrate is taken out from the concentrate tank 8. The concentrated liquid taken out is sent to a membrane treatment process or reuse.

  In the multistage treatment method shown in FIG. 3, the desalted liquid obtained by electrodialyzing the raw waste liquid sent from the waste liquid tank 14 by the pump 15 with the first electrodialysis apparatus 13-1 is used as the second electrodialysis apparatus 13. -2 with a pump 16 and electrodialyzed to concentrate and recover TAAH remaining in the desalted solution. The concentrated solution obtained by electrodialyzing the second electrodialyzer 13-2 and concentrating TAAH is subjected to the third electrodialysis together with the concentrated solution electrodialyzed by the first electrodialyzer 13-1 and transported by the pump 17. TAAH is concentrated to a higher concentration by electrodialysis with the device 13-3. The concentrated solution dialyzed by the third electrodialyzer 13-3 is sent to the membrane treatment process, reuse, etc., and the desalted solution treated by the third electrodialyzer 13-3 is sent to the pump 18 by the pump 18. 2 is sent back to the electrodialyzer 13-2, and the residual TAAH is concentrated and recovered by electrodialysis with the desalted liquid obtained by the first electrodialyzer 13-1. The desalted solution flowing out from the second electrodialyzer 13-2 is mostly a photoresist and has a low TAAH concentration, so it is discharged out of the system.

  Although not shown in FIG. 3, a low-concentration TAAH solution containing no (super) pure water or photoresist on the concentration cell side of the first electrodialyzer 13-1 [for example, a new product in (ultra) pure water. An electrolyte solution such as a solution in which a small amount of TAAH is dissolved] may be passed, and a concentrated solution with higher purity can be obtained. However, when the raw waste liquid is also sent to the concentration cell in both the systems shown in FIGS. 2 and 3, it is advantageous in that the amount (volume) of waste water discharged as the desalted liquid is reduced.

  Next, the principle of electrolysis in the case of performing electrolysis in the processing method for developing waste liquid according to the present invention will be described with reference to FIG. In addition, TAA ion demonstrates the normal case where the counter ion is OH ion and is the form of TAAH.

As shown in FIG. 4, a cation exchange membrane 23 is arranged between the cathode 21 and the anode 22 to constitute a cathode cell (C) and an anode cell (D). In theory, the cation exchange membrane allows only cations to pass through (actually, a slight amount of anions pass through). Through the anode cell (D), the raw waste liquid (treatment liquid obtained through ion exchange resin treatment or treatment liquid obtained through evaporation, reverse osmosis membrane treatment and ion exchange resin treatment) is passed through, and the cathode cell (C) For example, an electrolyte solution such as (ultra) pure water or a low-concentration TAAH solution (for example, a solution obtained by dissolving a small amount of new TAAH in (ultra) pure water) is passed through. Since TAAH in the raw waste liquid is dissociated into TAA ions (TAA ⁺ ) and OH ions (OH ⁻ ), when a direct current is applied between the cathode 21 and the anode 22, the TAA ions are positive ions, so the cathode ( -) Moves to the side, passes through the cation exchange membrane 23 and enters the cathode cell (C). On the cathode 21, hydrogen ions (H ⁺ ) of water (H ₂ O ← → H ⁺ + OH ⁻ ) receive electrons (e ⁻ ), generate hydrogen gas (H ₂ ), and the remaining anions, OH ions ( OH ⁻ ) becomes a counter ion of TAA ions that have entered the cathode cell (C) from the anode cell (D) and generates TAAH. Accordingly, as electrolysis proceeds, TAAH is concentrated in the cathode cell (C). In this sense, the cathode cell (C) functions as a concentration cell. On the other hand, on the anode 22, the OH ions (OH ⁻ ) of TAAH release electrons (e ⁻ ) to become oxygen gas (O ₂ ) and water. In this sense, the anode cell (D) functions as a desalting cell and produces a desalting solution (a “dilute” in which TAA ions are diluted).

Incidentally, Cl in the original waste ^- and Br ^- and the like of OH ^- from the electrolyzed easily ion species are included such as Cl ₂ or Br ₂ gas occurs. In this case, if the anode cell is further divided by an anion exchange membrane and an alkaline substance such as ammonium hydroxide is added to the anode side division cell, generation of gases such as Cl ₂ and Br ₂ can be prevented by neutralization. . Since hard than is electrolyzed, OH ^{- -} in the case of OH ^- SO ₄ ^2- and NO ₃ in it is then O ₂ is electrolysis occurs, H ₂ SO ₄ or HNO _3, etc. are left.
JP-A-57-155390

Also, instead of using a cation exchange membrane, use two neutral membranes such as porous Teflon (registered trademark) membrane that have been hydrophilized, and provide an anode chamber, an intermediate chamber, and a cathode chamber. Electrolysis can also be performed through.
Japanese Patent Laid-Open No. 60-247461

  If you want to obtain a TAAH concentrate with higher purity, place multiple (preferably two) cation exchange membranes between the cathode and anode, and pass the raw waste solution through the anode side cell (anode cell). In addition, the cathode side cell (cathode cell) and the intermediate cell have (ultra) pure water or a low-concentration TAAH solution that does not contain a photoresist [for example, a solution of a small amount of new TAAH in (ultra) pure water] When an electrolyte solution such as this is passed, TAAH is purified in multiple stages, and a high-purity TAAH concentrate is obtained from the cathode cell.

  The configuration used in the electrodialysis system of FIGS. 2 and 3 can be applied as it is to electrolysis.

  Here, “concentrated liquid” and “desalted liquid” are terms that are selectively used depending on whether the TAAH content increases or decreases, and do not indicate which TAAH concentration is higher or lower.

FIG. 1 is an explanatory diagram of the principle of electrodialysis when electrodialysis is performed in the method of the present invention. FIG. 2 is a flowchart for explaining an example of a process for carrying out electrodialysis in a circulating manner. FIG. 3 is a flowchart for explaining an example of a process for carrying out electrodialysis in a multistage processing system. FIG. 4 is an explanatory diagram of the principle of electrolysis when electrolysis is performed in the method of the present invention.

Explanation of symbols

1 Cathode 2 Anode 3 Cation exchange membrane (cation exchange membrane)
4 Anion exchange membrane (anion exchange membrane)
5 Electrodialyzer 6 Waste liquid tank 7 Desalted liquid tank 8 Concentrated liquid tank 9, 10, 11 Pump 12 Electric conductivity meter 13-1 First electrodialyzer 13-2 Second electrodialyzer 13-3 Third electrodialyzer Apparatus 14 Waste liquid tank 15, 16, 17, 18 Pump 21 Cathode 22 Anode 23 Cation exchange membrane

Claims (9)

In processing a photoresist development waste containing mainly photoresist and tetraalkylammonium ions, a cation exchange resin or cation exchange of the anion-exchange resin及beauty T AA type, Te tiger alkylammonium ion form (TAA type) A step of removing impurities from contact with a resin; and a step of concentrating and separating the processing liquid obtained through the above-described process by at least one of electrodialysis and electrolysis. A method for regenerating a photoresist developing waste solution, comprising reclaiming and recovering a solution of a high-purity tetraalkylammonium hydroxide that can be reused as a resist developer. The photoresist development waste is neutralized, and a step of separating and removing the photoresist became insoluble, neutralized solution T AA type cation-exchange resin obtained by the above process or an anion-exchange resin及beauty, It comprises at least a step of adsorbing and removing impurities by contacting with a TAA-type cation exchange resin, and a step of concentrating and separating the treatment liquid obtained through the two steps by electrodialysis and electrolysis or by electrolysis. The method for regenerating a photoresist developing waste liquid according to claim 1.   The method further includes the step of concentrating the photoresist developing waste solution or the processing solution thereof (or the neutralizing solution) by evaporating and / or reverse osmosis membrane treatment at least before the electrodialysis and / or electrolysis step. The method for reclaiming a photoresist developing waste liquid according to claim 1 or 2, characterized in that:   The method for regenerating a photoresist developing waste liquid according to any one of claims 1 to 3, wherein the anion exchange resin and the cation exchange resin are used as a mixed ion exchange resin.   The regeneration process of a photoresist developing waste liquid according to any one of claims 1 to 3, wherein the anion exchange resin is used as a laminated ion exchange resin in which the anion exchange resin is laminated on the upstream side and the cation exchange resin is laminated on the downstream side. Method.   4. The photo according to claim 1, wherein the anion exchange resin layer (column, tower) is disposed upstream of the cation exchange resin layer (column, tower). 5. A method for recycling resist developing waste liquid.   7. The photoresist development according to claim 1, wherein the anion exchange resin is a hydroxide ion form (OH form, that is, a hydroxide form) strongly basic anion exchange resin. Waste liquid recycling method. The method for processing a photoresist developing waste liquid according to any one of claims 1 to 7 , wherein at least one selected from electrodialysis and electrolysis is performed by a circulation system or a multistage system. The regeneration of a photoresist developing waste solution according to any one of claims 1 to 8 , wherein a film processing apparatus is disposed at or near the end to remove fine particles from a solution of high-purity tetraalkylammonium hydroxide. Processing method.

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