JP3656338B2 - Photoresist development waste liquid processing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a photoresist generated in the manufacturing process of electronic parts such as semiconductors, liquid crystals, and printed circuit boards, and a method for treating a photoresist developing waste solution containing tetraalkylammonium ions.
[0002]
[Prior art]
To manufacture electronic parts such as semiconductors, liquid crystals, and printed circuit boards, a negative or positive photoresist film is formed on a substrate such as a wafer, irradiated with light, etc. through a pattern mask, and then undesired by development. After dissolving and developing the photoresist, and further performing a process 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.
[0003]
As the alkali developer, an aqueous solution of 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 clear from the above, the tetraalkylammonium ion is usually in the form of a hydroxide having a hydroxide ion 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 wastewater 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 present specification, the counter ion is not specified, and the concept of “ion” is used. However, since the tetraalkylammonium ion in the waste liquid usually exists as a tetraalkylammonium hydroxide as described above, the present invention will be described mainly.
[0004]
Conventionally, in order to treat such photoresist and a photoresist developing waste solution containing tetraalkylammonium ions, a method of concentrating by an evaporation method or a reverse osmosis membrane method and disposal (incineration or taking over by a contractor), a biodegradation treatment by activated sludge There are known methods for release. In addition, the concentrated waste liquid obtained as described above or the concentrated waste liquid originally having a high tetraalkylammonium ion concentration is preferably converted to a tetraalkylammonium ion by the electrodialysis method or the electrolysis method in the form of a hydroxide (necessarily in the electrolysis method). Attempts have been made to recover and reuse it in the form of a hydroxide).
[0005]
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. . In addition, in a method of recovering tetraalkylammonium ions, preferably in the form of hydroxide by electrodialysis or electrolysis (which is necessarily in the form of hydroxide in the electrolysis method), high purity is required for reuse as a developer. However, there is a problem that a small amount of photoresist remains.
[0006]
[Problems to be solved by the invention]
Accordingly, an object of the present invention is to provide a simple and effective method for treating a photoresist developing waste solution by eliminating the disadvantages of conventional processing methods for photoresist developing waste solution containing photoresist and tetraalkylammonium ions. is there.
[0007]
[Means for Solving the Problems]
  The present invention relates to a processing method of a photoresist developing waste liquid containing a photoresist and tetraalkylammonium ions.SaidPhotoresist development wasteElectrodialysis or electrolysis to obtain a concentrate mainly containing tetraalkylammonium ions, andConcentrateStrongly basicAnion exchangeresinContact withRemaining in the concentratePhotoresistStrongly basicAnion exchangeresinA method for treating a photoresist developing waste liquid, comprising a step of removing the photoresist by adsorbing to a photoresistIn the processing method of a photoresist developing waste solution containing photoresist and tetraalkylammonium ions, the photoresist developing waste solution is contacted with a strongly basic anion exchange resin, and the photoresist is adsorbed on the strongly basic anion exchange resin. A process for obtaining a photoresist developing waste solution, and a process for concentrating tetraalkylammonium ions by electrodialyzing or electrolyzing the treated water, and a photoresist and In the processing method of a photoresist developing waste solution containing tetraalkylammonium ions, the step of neutralizing the photoresist developing waste solution and separating and removing the insoluble photoresist to obtain a neutralized processing solution, the neutralizing solution In contact with a strongly basic anion exchange resin Photoresist development comprising: a step of obtaining a processing solution removed by adsorbing a photoresist on a strongly basic anion exchange resin; and a step of electrolyzing the processing solution to concentrate tetraalkylammonium hydroxide. Waste liquid treatment methodIs to provide.
[0008]
  In the method of the present invention, a photoresist alkaline developer waste solution containing photoresist and tetraalkylammonium ions (hereinafter sometimes abbreviated as “developer waste solution”) is directly subjected to anion exchange.resinAs described in detail below, the developer waste solution is concentrated in advance by electrodialysis or electrolysis to obtain a concentrate mainly containing tetraalkylammonium ions having a reduced amount of photoresist, and this is negatively affected. Ion exchangeresinOr by neutralizing the development waste solution in advance to remove the photoresist to some extent, to obtain a neutralization treatment solution mainly containing tetraalkylammonium ions with a reduced amount of photoresist, ExchangeresinAnion exchange is in contact withresinFrom the viewpoint of the exchange capacity. In addition, the development waste liquid containing a tetraalkylammonium hydroxide and a photoresist usually exhibits an alkaline property of pH 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, etc., and during development these form tetraalkylammonium salts that dissolve the photoresist in the developer. When the pH is 10 or less, preferably 8 or less (which may be acidic), it becomes a carboxyl group again and the photoresist becomes insoluble, and most of the photoresist can be removed by a method such as filtration. In this specification, a processing solution obtained by neutralizing the development waste solution and removing the photoresist to some extent by a method such as filtration is referred to as a “neutralization processing solution”.
[0009]
  In the present invention, a strongly basic anion exchange resin is used in terms of photoresist removal efficiency.From the viewpoint of processing efficiency, an organic anion exchange resin such as fibrous or granular styrene or acrylic is preferable, and a styrene anion exchange resin is particularly preferable from the viewpoint of photoresist removal efficiency, as will be described later. The acrylic anion exchange resin is obtained by crosslinking (meth) acrylic acid or its ester with divinylbenzene (DVB) or the like.. MaIn addition, the counter ion form of the anion exchange resin is OH^- But Cl^- Etc., but Cl^- When an anion exchange resin of the form is used, the counter ion of tetraalkylammonium is at least partially Cl^- OH^- It is preferable to use an anion exchange resin in the form.
[0010]
  Anion exchange of developing waste liquid, concentrated liquid or neutralized liquidresinThe treatment solution obtained by contacting with the solution may be further concentrated by electrodialysis, electrolysis, evaporation, reverse osmosis, or a combination of these, and anion exchangeresinWhen concentration is not performed before contact with the developer (development waste solution or neutralized solution is anion exchanged)resinIn the case of contact with (a), it is particularly preferable to perform such concentration from the viewpoint of recovery and reuse of tetraalkylammonium ions. In the case of electrolysis, the counter ion of the tetraalkylammonium ion is a hydroxide ion (OH^- ), The counter ion of the tetraalkylammonium ion in the concentrate is OH^- Therefore, the electrolysis after the neutralization is particularly convenient for reuse as a photoresist developer.
[0011]
  Anion exchangeresinWhen concentrating tetraalkylammonium ions by electrodialysis or electrolysis, before or after contact with the aqueous solution, from the viewpoint of the purity of the resulting tetraalkylammonium ion concentrate, at least one of electrodialysis or electrolysis is performed in multiple stages. Preferably it is done. In particular, when the recovered concentrated solution is reused as a developer, multistage electrodialysis or electrolysis is preferable.
[0012]
Tetraalkylammonium ions in photoresist alkaline developer wastewater are tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutyl used in photoresist developers used in the production of various electronic components. Ammonium hydroxide, methyltriethylammonium hydroxide, trimethylethylammonium hydroxide, dimethyldiethylammonium hydroxide, trimethyl (2-hydroxyethyl) ammonium hydroxide, triethyl (2-hydroxyethyl) ammonium hydroxide, dimethyldi (2-hydroxyethyl) Ammonium hydroxide, diethyldi (2-hydroxyethyl) ammonium Derived from tetraalkylammonium hydroxides such as peroxide, methyltri (2-hydroxyethyl) ammonium hydroxide, ethyltri (2-hydroxyethyl) ammonium hydroxide, tetra (2-hydroxyethyl) ammonium hydroxide, etc. To do.
[0013]
The counter-ion of tetraalkylammonium ion in the development waste liquid or the counter-ion of tetraalkylammonium ion in the concentrated or neutralized solution is usually a hydroxide ion as described above. Depending on the neutralization, fluoride ion, chloride ion, bromide ion, carbonate ion, bicarbonate ion, sulfate ion, hydrogen sulfate ion, nitrate ion, phosphate ion, hydrogen phosphate ion, phosphate In general, at least one selected from inorganic anions such as dihydrogen ions and organic anions such as formate ion, acetate ion, and oxalate ion is a counter ion of 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 electrolyzed treated water, hydroxide ions are usually counter ions of tetraalkylammonium ions.
[0014]
In ordinary photoresist development waste, the photoresist is dissolved as an anionic polymer due to carboxyl groups and the like, while the tetraalkylammonium hydroxide is a cation, a tetraalkylammonium ion and an anion. Dissociated into hydroxide ions.
[0015]
  Such waste liquidStrongly basicAnion exchangeresinThe photoresist in the waste liquid.Strongly basicAnion exchangeresinIt can be adsorbed and removed.
[0016]
  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. Anion exchangeresinEspecially with styrenic benzene ringsStrongly basicWhen an anion exchange resin or the like is used, it is considered that the photoresist can be removed with high selectivity by the affinity (hydrophobic) interaction between benzene rings in addition to the electrostatic interaction.
[0017]
  For this reason, it goes without saying that the tetraalkylammonium hydroxide concentration is low, and even when the tetraalkylammonium hydroxide concentration is high, a large amount of competing hydroxide ions (derived from tetraalkylammonium hydroxide) in the waste liquid. In spite of coexistence with the above, the photoresist is effectively and selectively used as described above.Strongly basicAnion exchangeresinIt can be adsorbed and removed.
[0018]
  That is, the tetraalkylammonium hydroxide solution (concentrated solution) recovered by electrodialysis or electrolysis of the photoresist development waste liquid has a relatively high tetraalkylammonium hydroxide concentration.Strongly basicAnion exchangeresinCan be removed and removed as a high-purity developer and reused.
[0019]
  Prior to concentration by electrodialysis or electrolysis, remove the photoresist developer waste as described above.Strongly basicAnion exchangeresinWhen the contact treatment is performed, the photoresist is easily removed because the concentration of tetraalkylammonium hydroxide in the developing waste solution is low. Therefore, in this case, since the tetraalkylammonium hydroxide solution containing almost no photoresist is concentrated by electrodialysis or electrolysis, the resulting treated water can be recycled and reused as a high-purity developer.
[0020]
  Anion exchange for developer waste containing high concentrations of photoresistresinFrom the viewpoint of the ion exchange capacity, after neutralizing as a pretreatment, the photoresist is insolubilized and separated and removed by a method such as filtration.resinAnion exchange of residual photoresistresinThe neutralization of the tetraalkylammonium hydroxide into a tetraalkylammonium salt is advantageous. When the solution (neutralizing solution) mainly containing the tetraalkylammonium salt thus obtained is concentrated by electrodialysis or electrolysis, a high-purity tetraalkylammonium salt (in the case of electrodialysis) or tetraalkylammonium hydroxide ( In the case of electrolysis). In the case of electrolysis, or in the case of electrodialysis, it can be further electrolyzed and recovered in the form of tetraalkylammonium hydroxide, which can be recycled and reused as a high-purity developer.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
Examples of the embodiment of the present invention as described above can include the following embodiments, but it goes without saying that the present invention is not limited to these embodiments.
[0024]
  <1>A tetraalkylammonium ion concentrate obtained by electrodialysis of a photoresist development waste solution containing photoresist and tetraalkylammonium ions,Strongly basicAnion exchangeresinThe photoresist remaining in the concentrated solution.Strongly basicAnion exchangeresinA method for treating a photoresist developing waste liquid which is removed by adsorbing to a photoresist.
[0025]
  <2>Photoresist development waste solution containing photoresist and tetraalkylammonium ions,Strongly basicAnion exchangeresinIn contact with the photoresistStrongly basicAnion exchangeresinA method for treating a photoresist developing waste solution, which is removed by adsorbing to a solution and then concentrated by electrodialysis with tetraalkylammonium ions.
[0026]
  <3>Tetraalkylammonium ions (in the case of electrolysis, in the form of a hydroxide having a hydroxide ion as a counter ion) concentrate obtained by electrolyzing a photoresist developing waste solution containing photoresist and tetraalkylammonium ions TheStrongly basicAnion exchangeresinThe photoresist remaining in the concentrated solution.Strongly basicAnion exchangeresinA method for treating a photoresist developing waste liquid which is removed by adsorbing to a photoresist.
[0027]
  <4>Photoresist development waste solution containing photoresist and tetraalkylammonium ions,Strongly basicAnion exchangeresinIn contact with the photoresistStrongly basicAnion exchangeresinA method for treating a photoresist developing waste solution, which is removed by adsorbing to a photocatalyst and then concentrated by electrolysis with a tetraalkylammonium ion (in the case of electrolysis, it is in the form of a hydroxide having a hydroxide ion as a counter ion).
[0028]
  <5>After neutralizing the photoresist developing waste solution containing the photoresist and tetraalkylammonium hydroxide and separating and removing the insoluble photoresist,Strongly basicAnion exchangeresinThe residual photoresist.Strongly basicAnion exchangeresinA method for treating a photoresist developing waste solution, which is removed by adsorbing to a water and concentrating tetraalkylammonium hydroxide by electrolysis.
[0029]
  ElectricWhen the counter ion of tetraalkylammonium ion after air dialysis is an ion other than hydroxide ion and forms a salt, the concentrated solution obtained by electrodialysis is further concentrated as tetraalkylammonium hydroxide by electrolysis. This is convenient for reuse as a photoresist developer.
[0030]
An example in the case where the development waste solution is regenerated and reused as a photoresist developer by the embodiment of the present invention using the electrodialysis method will be described more specifically. As a photoresist developer, an aqueous solution having a tetramethylammonium hydroxide concentration of 2.38% by weight is most commonly used. When the photoresist is developed with this developer, a development waste solution containing a photoresist and tetramethylammonium hydroxide is usually generated. This development waste solution is concentrated by electrodialysis to obtain a tetramethylammonium hydroxide concentrated solution. The concentrated solution is contacted with an anion exchange resin to remove the photoresist remaining in the concentrated solution by adsorbing the anion exchange resin, and if necessary, the treatment solution is further concentrated by electrodialysis. In this case, the developer waste solution contains Na due to contamination from chemicals and elution from piping materials.⁺, K⁺, Ca²⁺, Fe²⁺, Fe³⁺, Cu²⁺, Al³⁺In general, these metal ions are not removed by electrodialysis, but are concentrated instead. Therefore, when the obtained concentrated solution is used as a regenerated developer as it is, these metal ions may adversely affect the production of electronic components. Therefore, it is not concentrated to an aqueous solution having a tetramethylammonium hydroxide concentration of 2.38% by weight by electrodialysis, but is concentrated to an aqueous solution having a tetramethylammonium hydroxide concentration of about 1% by weight, When the concentration of tetramethylammonium hydroxide is adjusted to 2.38% by weight with a concentrated aqueous solution of about 20% by weight ammonium hydroxide and reused as a photoresist developer, the concentration of the above metal ions is kept low. This is convenient.
[0031]
Next, the principle in the case of performing electrodialysis in the processing method of the developing waste liquid of the present invention will be described with reference to FIG. In addition, the tetraalkylammonium ion will explain the normal case where the counter ion is a hydroxide ion and is in the form of a hydroxide.
[0032]
  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. Raw waste solution (development waste solution or anion exchange) containing tetraalkylammonium hydroxide and photoresist sent to the cellresinTetraalkylammonium hydroxide in the waste liquid after treatment with tetraalkylammonium ion (TAA) as a cation.⁺ ) And hydroxide ions as anions (hereinafter referred to as “hydroxide ions”) (OH^- Therefore, when a direct current is applied between the cathode 1 and the anode 2, the tetraalkylammonium ions move to the cathode side through the cation exchange membrane 3, but are blocked by the next anion exchange membrane. On the other hand, since the hydroxide ions move to the anode side through the anion exchange membrane 4 but are blocked by the next cation exchange membrane, in some cells, the tetraalkylammonium hydroxide is concentrated and adjacent to the cell. In this cell, tetraalkylammonium hydroxide is reduced. That is, the cell (A) having the anion exchange membrane 4 on the side facing the cathode 1 functions as a concentration cell. Here, the tetraalkylammonium hydroxide is concentrated to become a concentrated solution, and the anion exchange membrane 4 is converted into the anode 2. The cell (B) on the side facing the surface functions as a desalting cell, where tetraalkylammonium hydroxide 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.
[0033]
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 tetraalkylammonium hydroxide 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 that in the raw waste solution. This is clearly different from the evaporation method and reverse osmosis membrane method in which not only the oxide but also the photoresist is concentrated at the same time.
[0034]
When obtaining a concentrated solution containing almost no photoresist, the raw waste solution is passed through the desalting cell side, and pure water or a low-concentration tetraalkylammonium hydroxide solution containing no photoresist (for example, pure water) An electrolyte solution such as a solution in which a small amount of a new tetraalkylammonium hydroxide is dissolved in water may be passed, and this is convenient when the concentrated solution is reused as a photoresist developer.
[0035]
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, for example, the thickness is 0.1 to 0.6 mm, and the resistance is 1 to 10 Ω · cm.²It is sufficient if it is of the order.
[0036]
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.
[0037]
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 pass tetraalkylammonium ions, but their permeability is lower than that of cation exchange membranes. Concentration of tetraalkylammonium ions 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.
[0038]
Examples of the electrodialysis process include a circulation system as shown in FIG. 2 and a multistage treatment system as shown in FIG.
[0039]
  In the circulation system shown in FIG. 2, the raw waste liquid is sent from a waste liquid tank 6 containing a raw waste liquid containing a tetraalkylammonium hydroxide and a photoresist to a desalting liquid tank 7 by a pump 9 and from the desalting liquid tank 7 to a pump 10. Is sent to the desalting cell of the electrodialysis apparatus 5 to which a direct current is applied, and the desalting solution flowing out from the desalting cell is returned to the desalting solution tank 7 for circulation. On the other hand, the raw waste liquid is also charged in the concentrated liquid tank 8 and sent to the concentrated cell of the electrodialyzer 5 by the pump 11, and the concentrated liquid flowing out is returned to the concentrated liquid 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 tetraalkylammonium hydroxide concentration in the concentrated liquid tank 8 reaches a predetermined concentration, the concentrated liquid is taken out from the concentrated liquid tank 8. The extracted concentrate is anion exchangeresinIt is used for contact process and reuse.
[0040]
  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 by a pump 16 and electrodialyzed to concentrate and recover the tetraalkylammonium hydroxide remaining in the desalted solution. The concentrated solution obtained by electrodialysis in the second electrodialysis apparatus 13-2 and concentrated in the tetraalkylammonium hydroxide is mixed with the concentrated liquid electrodialyzed in the first electrodialysis apparatus 13-1 and transported by the pump 17. The tetraalkylammonium hydroxide is further concentrated to a high concentration by electrodialysis with the electrodialysis apparatus 13-3. The concentrated solution electrodialyzed by the third electrodialyzer 13-3 is anion exchanged.resinThe desalted liquid that has been used in the contact process and reuse, etc., and processed by the third electrodialysis apparatus 13-3 is sent to the second electrodialysis apparatus 13-2 by the pump 18, and the first electrodialysis apparatus is used. Concentration and recovery of the remaining tetraalkylammonium hydroxide by electrodialysis with the desalted solution obtained in the apparatus 13-1. Most of the desalted solution flowing out from the second electrodialyzer 13-2 is a photoresist, and since the concentration of tetraalkylammonium hydroxide is low, it is discharged out of the system.
[0041]
Next, the principle in the case of performing electrolysis in the processing method of the developing waste liquid of the present invention will be described with reference to FIG. In addition, the tetraalkylammonium ion will explain the normal case where the counter ion is a hydroxide ion and is in the form of a hydroxide.
[0042]
  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). Raw waste liquid (development waste liquid or anion exchange) in anode cell (D)resinWaste solution after treatment with a low-concentration tetraalkylammonium hydroxide solution containing no pure water or photoresist (for example, a small amount of new tetraalkylammonium hydroxide in pure water). An electrolyte solution such as a dissolved solution is passed through. Tetraalkylammonium hydroxide in the raw liquid waste is tetraalkylammonium ion (TAA).⁺ ) And hydroxide ions (OH)^- Therefore, when a direct current is applied between the cathode 21 and the anode 22, the tetraalkylammonium ions move to the cathode (−) side through the cation exchange membrane 23 because they are cations. Enter (C). On the cathode 21, water (H₂ O ← → H⁺ + OH^- ) Hydrogen ion (H⁺ ) Is an electron (e^- ) And receive hydrogen gas (H₂ ) And the remaining anion, the hydroxide ion (OH^- ) Becomes a counter ion of the tetraalkylammonium ion that has entered the cathode cell (C) from the anode cell (D), and produces a tetraalkylammonium hydroxide. Accordingly, as the electrolysis proceeds, tetraalkylammonium hydroxide 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, a hydroxide ion of tetraalkylammonium hydroxide (OH^- ) Is an electron (e^- ) And oxygen gas (O₂ ) And water. In this sense, the anode cell (D) functions as a desalting cell.
[0043]
In the raw waste liquid, Cl^-And Br^-OH etc.^-Cl containing ionic species that are more easily electrolyzed₂And Br₂Gas is produced. In this case, as disclosed in JP-A-57-155390, when 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, Cl due to neutralization₂And Br₂Generation of such gases can be prevented. SO_Four ^2-Or NO_Three ^-In the case of OH^-OH^-Is electrolyzed and O₂Occurs and H₂SO_FourAnd HNO_ThreeEtc. remain.
[0044]
If you want to obtain a highly pure tetraalkylammonium hydroxide concentrate, place multiple (preferably two) cation exchange membranes between the cathode and anode, and use the raw waste solution in the anode cell (anode cell). Let the cell on the cathode side (cathode cell) and the intermediate cell contain pure water or a low-concentration tetraalkylammonium hydroxide solution containing no photoresist (for example, a small amount of new tetraalkylammonium hydroxide in pure water) When an electrolyte solution such as a dissolved solution is passed, tetraalkylammonium hydroxide is purified in multiple stages, and a highly pure tetraalkylammonium hydroxide concentrate is obtained from the cathode cell.
[0045]
【Example】
EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, it cannot be overemphasized that this invention is not what is limited to these Examples.
[0046]
referenceExample 1
  A photoresist developing waste solution containing photoresist and tetramethylammonium hydroxide (TMAH) discharged from the liquid crystal manufacturing process was used. As for the water quality of this waste liquid, the TMAH concentration was 3000 mg / L, the photoresist-derived TOC was 65 mg / L, and the pH was 12. The TMAH concentration was measured by ion chromatography analysis, and the photoresist concentration was measured by absorptiometric analysis.
[0047]
  Anion exchangeresinAs an ion exchange resin column using a OH form of strong basic anion exchange resin Amberlite IRA-402BL (Rohm and Haas) and packed in a column of length 300 mm x diameter 25 mm and height 150 mm Prepared. 500 ml of the waste liquid was passed through this ion exchange resin column at a flow rate of 20 ml / min, and the TMAH concentration and the photoresist concentration in the treatment liquid were measured. The TMAH concentration was 3000 mg / L, and the photoresist concentration was TOC 0.5 mg / L. Where anion exchangeresinAs the above, other than the above ion exchange resin may be used. However, when reusing as a developer, clean anion exchange with less eluateresinIs preferably used. The above-described treatment can be applied to all alkali developing waste liquids of tetraalkylammonium hydroxide such as tetraethylammonium hydroxide.
[0048]
Example1
  the abovereferenceTMAH was concentrated using an electrodialyzer using the processing solution of Example 1 (TMAH concentration: 3000 mg / L, photoresist concentration: 0.5 mg / L with TOC) as a sample solution. The electrodialysis apparatus uses a micro-acylator G3 manufactured by Asahi Kasei Kogyo Co., Ltd. In this apparatus, cation exchange membrane Aciplex K-501 (manufactured by Asahi Kasei Kogyo Co., Ltd.) and anion exchange membrane Aciplex A-201 [ Asahi Kasei Kogyo Co., Ltd.] was used. Here, other ion exchange membranes may be used, and neutral membranes such as Aciplex PVA # 100 (manufactured by Asahi Kasei Kogyo Co., Ltd.) may be used instead of the anion exchange membrane. There is no problem.
[0049]
Current-carrying area 40cm²Effective membrane area 400cm²Then, circulation concentration was performed for 1 hour under the conditions of a voltage of 12 V, a sample solution of 2000 ml, and a concentrated solution (starting with pure water to make a concentrated solution) of 200 ml. The obtained concentrated solution had a TMAH concentration of 18000 mg / L, a photoresist concentration of TOC of 0.1 mg / L or less, and a pH of 13. This could be used sufficiently as a developer.
[0050]
Example2
  referenceElectrodialysis apparatus for concentrating TMAH under the same conditions as in Example 2 using the same photoresist development waste solution as in Example 1 (TMAH concentration: 3000 mg / L, TOC derived from photoresist: 65 mg / L, pH: 12) as a sample solution It was performed using. The obtained concentrated solution had a TMAH concentration of 18000 mg / L, a photoresist concentration of TOC of 8 mg / L, and a pH of 13.
[0051]
  Anion exchangeresinAs an ion exchange resin column using a OH form of strong basic anion exchange resin Amberlite IRA-402BL (Rohm and Haas) and packed in a column of length 300 mm x diameter 25 mm and height 150 mm Prepared. 500 ml of the concentrated solution was passed through this ion exchange resin column at a flow rate of 20 ml / min, and the TMAH concentration and the photoresist concentration in the processing solution were measured. The TMAH concentration was 18000 mg / L, and the photoresist concentration was TOC of 0.1 mg / L or less. This could be used sufficiently as a developer.
[0052]
【The invention's effect】
  In the method for treating a photoresist developing waste solution of the present invention, a tetraalkylammonium ion-containing solution (developing waste solution) containing at least a photoresist.Or by electrodialysis or electrolysisConcentrated solution or neutralized solution)Strongly basicAnion exchangeresinRemove the photoresist by contacting withIn some cases, further electrodialysis and electrolysis are performed.A highly pure tetraalkylammonium ion-containing solution can be obtained.
[Brief description of the drawings]
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 by a circulation method.
FIG. 3 is a flowchart for explaining an example of a process for carrying out electrodialysis in a multistage processing method.
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 Desalination tank
8 Concentrated liquid tank
9, 10, 11 Pump
12 Electric conductivity meter
13-1 First electrodialysis machine
13-2 Second electrodialysis machine
13-3 Third electrodialysis machine
14 Waste liquid tank
15, 16, 17, 18 Pump
21 Cathode
22 Anode
23 Cation exchange membrane

Claims (6)

In the photoresist processing method development waste containing photoresist and tetraalkylammonium ions, the photoresist development waste by electrodialysis or electrolysis to obtain a concentrate containing mainly a tetraalkylammonium ion, and the concentrate It is contacted with a strongly basic anion exchange resin, photoresist processing method of development waste, which comprises a step of removing by adsorption of photoresist remaining in the concentrate to a strongly basic anion exchange resin . In the processing method of a photoresist developing waste solution containing photoresist and tetraalkylammonium ions, the photoresist developing waste solution is brought into contact with a strongly basic anion exchange resin, and the photoresist is adsorbed on the strongly basic anion exchange resin. A method for treating a photoresist developing waste solution, comprising: obtaining a treatment solution removed by the step of: and concentrating tetraalkylammonium ions by electrodialysis or electrolysis of the treatment solution . In the processing method of a photoresist development waste containing photoresist and tetraalkylammonium ions, the photoresist development waste was neutralized to obtain a neutralize treatment liquid photoresist became insoluble separated and removed in the abovementioned the sum processing solution is contacted with a strongly basic anion exchange resin, to obtain a treating liquid was removed by adsorbing the residual photoresist strongly basic anion exchange resin, and, by electrolysis of the treatment liquid tetra method of processing full photoresists development waste you comprising the step of concentrating the alkyl ammonium hydroxide oxide. The strongly basic anion exchange resin is OH ^- 4. The method for processing a photoresist developing waste liquid according to claim 1, wherein the processing method is a shape.   The counter ion of tetraalkylammonium ion in the photoresist developing waste liquid, or the counter ion of tetraalkylammonium ion in the concentrated or neutralized solution is a hydroxide ion, fluoride ion, chloride ion, bromide ion, From inorganic anions such as carbonate ion, bicarbonate ion, sulfate ion, hydrogen sulfate ion, nitrate ion, phosphate ion, hydrogen phosphate ion, dihydrogen phosphate ion and organic anions such as formate ion, acetate ion, oxalate ion 5. The method for processing a photoresist developing waste liquid according to claim 1, wherein the processing method is at least one selected. Method of processing a photoresist development waste according to any one of claims 1 to 5, characterized in that performing at least one multi-stage selected from the electrolyte and the electrodialysis.

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