Combination of slurry copper waste and concentrated copper waste for the treatment of azole, metal, and silica solids in wastewater.

Abstract

The disclosed method for removing organic compounds from a copper-containing solution includes generating a copper-containing solution from a mixture of wastewater from a copper chemical mechanical polishing (CMP) operation at a semiconductor fabrication facility and a concentrated copper waste stream (CCW) from the semiconductor fabrication facility, and introducing an oxidizing agent to the copper-containing solution, wherein the copper catalyzes the production of hydroxyl radicals from the oxidizing agent that react with the organic compounds.

Description

[Technical Field]

[0001] Aspects and embodiments disclosed herein relate to systems and methods for the treatment of wastewater, such as copper chemical mechanical polishing (CMP) wastewater containing organic contaminants such as azoles. The methods disclosed herein provide for the destruction of organic contaminants in the wastewater using a modified Fenton's reagent that utilizes copper as a catalytic agent from the combined waste stream of a semiconductor manufacturing facility. Summary of the Invention

[0002] According to one aspect, a method for removing organic compounds from a copper-containing solution is provided, the method comprising the steps of generating a copper-containing solution from a mixture of wastewater from a copper chemical mechanical polishing (CMP) operation at a semiconductor fabrication facility and a concentrated copper waste stream (CCW) from the semiconductor fabrication facility, and introducing an oxidizing agent to the copper-containing solution, wherein the copper catalyzes the generation of hydroxyl radicals from the oxidizing agent that react with the organic compounds.

[0003] In some embodiments, the method further comprises maintaining the pH of the copper-containing solution in the container at a level at which the copper catalyzes the production of hydroxyl radicals from the oxidizing agent.

[0004] In some embodiments, the method further comprises maintaining a pH of the copper-containing solution in the container between about 2 and about 4.

[0005] In some embodiments, the method further comprises maintaining the temperature of the copper-containing solution in the vessel at about 55°C to about 65°C.

[0006] In some embodiments, the step of introducing an oxidizing agent to the copper-containing solution comprises introducing hydrogen peroxide to the copper-containing solution.

[0007] In some embodiments, the method further comprises maintaining a concentration of hydrogen peroxide in the copper-containing solution in the container at 250 mg / L or greater.

[0008] In some embodiments, the method further comprises obtaining hydrogen peroxide from a waste stream from a semiconductor manufacturing facility.

[0009] In some embodiments, the step of producing the copper-containing solution comprises mixing at least 1 part CCW with 25 parts CMP wastewater, or mixing at least 1 part CCW with 10 parts CMP wastewater.

[0010] In some embodiments, the step of removing organic compounds from the copper-containing solution comprises removing one or more azole compounds from the copper-containing solution.

[0011] In some embodiments, the step of generating the copper-containing solution includes mixing CCW with CMP wastewater in an amount sufficient to provide 20 parts by weight of copper per 1 part by weight of the one or more azole compounds.

[0012] In some embodiments, removing organic compounds from the copper-containing solution comprises removing one or more of 1,2,4-triazole, 1H-benzotriazolepyrazole, benzotriazole, 5-methyl 1H-benzotriazole (tolutriazole), or 3-amino 1,2,4-triazole from the copper-containing solution.

[0013] According to another aspect, a system for removing organic compounds from wastewater from a semiconductor fabrication facility is provided, the system including: a vessel fluidly connectable to a wastewater source; a copper source configured to introduce copper into the wastewater in the vessel, the copper source comprising a concentrated copper waste stream from the semiconductor fabrication facility; an oxidant source configured to introduce an oxidant into the wastewater in the vessel; and a pH-adjusting chemical source configured to introduce a pH-adjusting chemical into the wastewater in the vessel.

[0014] In some embodiments, the system further comprises a pH monitor disposed within the vessel and a controller configured to control the pH-adjusting chemical source to introduce a pH-adjusting chemical into the wastewater in the vessel in an amount and at a rate sufficient to maintain the pH of the wastewater at a level at which copper catalyzes the production of hydroxyl radicals from the oxidizing agent.

[0015] In some embodiments, the controller is configured to control the pH-adjusting chemical source to introduce the pH-adjusting chemical into the wastewater in the vessel in an amount and at a rate sufficient to maintain the pH of the wastewater at about 2 to about 4.

[0016] In some embodiments, the system further comprises a heater, and the controller is further configured to control the heater to maintain a temperature of the wastewater in the vessel between about 55°C and about 65°C.

[0017] In some embodiments, the oxidant source is a hydrogen peroxide source, and the controller is further configured to control the oxidant source to maintain a concentration of hydrogen peroxide in the wastewater in the vessel at or above 250 mg / L.

[0018] In some embodiments, the hydrogen peroxide source comprises a waste stream from a semiconductor manufacturing facility.

[0019] In some embodiments, the wastewater contains one or more copper corrosion inhibitors, and the system is configured such that the copper acts as a catalyst for the production of hydroxyl radicals, and the hydroxyl radicals produced from the oxidizing agent decompose the copper corrosion inhibitors.

[0020] In some embodiments, the wastewater contains one or more azole compounds, and the system is configured such that the copper acts as a catalyst for the generation of hydroxyl radicals, and the hydroxyl radicals generated from the oxidant decompose the one or more azoles.

[0021] In some embodiments, the wastewater contains one or more of 1,2,4-triazole, 1H-benzotriazolepyrazole, benzotriazole, 5-methyl-1H-benzotriazole (tolutriazole), or 3-amino-1,2,4-triazole, and the system is configured such that the copper acts as a catalyst for the generation of hydroxyl radicals, and the hydroxyl radicals generated from the oxidant degrade the one or more of 1,2,4-triazole, 1H-benzotriazolepyrazole, benzotriazole, tolutriazole, or 3-amino-1,2,4-triazole.

[0022] In some embodiments, the wastewater source is a unit operation in a semiconductor manufacturing facility.

[0023] In some embodiments, the wastewater source is a copper CMP operation in a semiconductor manufacturing facility.

[0024] In some embodiments, the copper source comprises a copper plating operation in a semiconductor manufacturing facility.

[0025] The accompanying drawings are not intended to be drawn to scale. In the drawings, each identical or nearly identical component is designated by a like numeral. For clarity, not all components may be labeled. [Brief explanation of the drawings]

[0026] [Figure 1] 1 illustrates an example of a system disclosed herein. DETAILED DESCRIPTION OF THE INVENTION

[0027] The chemical mechanical polishing (CMP) planarization process involves removing and / or etching semiconductor wafers during the manufacturing process using a polishing slurry containing oxidizers, abrasives, complexing agents, and additives. Polishing is performed using a polishing pad to remove excess copper from the semiconductor wafer. Silicon, copper, and various trace metals are removed from the silicon structure via the polishing slurry. The polishing slurry is introduced in combination with the polishing pad to the silicon wafer on the planarization table. Oxidizers and etchants are introduced to control material removal. Deionized water rinses are generally used to remove debris from the silicon wafer. UPW, demineralized water, and polishing water from reverse osmosis (RO) can also be used to rinse silicon wafers in semiconductor manufacturing facility equipment.

[0028] An oxidizer, hydrogen peroxide (H2O2), is typically used to help dissolve copper from the microchips, so levels of about 300 ppm or more of hydrogen peroxide (H2O2) may also be present in the by-product polishing slurry wastewater.

[0029] In the manufacturing process of semiconductor devices, the CMP step for polishing copper surfaces when mounting copper wiring generates a large amount of wastewater containing copper corrosion inhibitors, and therefore, treatment of the wastewater is desirable to prevent the release of undesirable pollutants into the environment.

[0030] Among copper corrosion inhibitors, azole-type copper corrosion inhibitors in particular have excellent corrosion inhibitory effects. However, azole-type copper corrosion inhibitors usually have a chemically stable structure and are not easily biodegradable. For this reason, in the treatment of wastewater containing azole-type copper corrosion inhibitors discharged from processes, the azole-type copper corrosion inhibitors are decomposed using an oxidizing agent with high oxidizing power, such as ozone, ultraviolet light, or hydrogen peroxide, or an advanced oxidation process using a combination of these oxidizing agents, and the treated water is then discharged or recovered.

[0031] However, as mentioned above, because azole-type copper corrosion inhibitors are chemically stable, even when a highly oxidizing agent such as ozone is used, the oxidative decomposition of the azole-type copper corrosion inhibitor requires the addition of a large amount of the oxidizing agent, which poses a significant problem from the viewpoint of cost. In particular, in recent years, with the increasing integration of semiconductor devices, the number of fine polishing steps has increased, and the amount of polishing wastewater discharged has also increased. Therefore, the increased cost due to the increased capacity of wastewater treatment facilities has become a problem.

[0032] Fenton's reagent is often used to treat organic compounds. It can be made by adding 10 parts peroxide to 1 part ferrous peroxide (ferrous sulfate) for every 0.3 parts of organic compound.

[0033] Fenton's reagent is effective in treating some azoles, such as pyrazoles. However, laboratory tests have shown that other forms of azoles, such as 1,2,4-triazoles, are not degraded by exposure to Fenton's reagent.

[0034] As mentioned above, azoles are often used as corrosion inhibitors in facilities that manufacture computer chips. These facilities also typically have high copper-containing wastewater from the CMP process, which is treated and disposed of at the facility's expense after use. In one embodiment, azole compounds in the wastewater are treated and decomposed by substituting a waste copper stream for iron in Fenton's reagent (a Fenton-like reagent). Testing has shown that 1,2,4-triazole, 1H-benzotriazole, and methylbenzotriazole:4,5-tolyltriazole can all be treated using copper-substituted Fenton's reagent. In one test, waste hydrogen peroxide (containing the azole to be treated) and waste copper sulfate, which can be used in place of iron sulfate in the Fenton reaction, were used to produce an oxidant-containing solution that effectively decomposed the azole.

[0035] In some embodiments, copper replaces iron in a modified Fenton reaction, or reaction referred to herein as a Fenton-like reaction. A waste copper stream from a semiconductor manufacturing facility can be used as a copper source. Waste copper can be present in the effluent of a copper CMP process, referred to herein as slurry copper waste (SCW). More specifically, in some aspects and embodiments, a combination of SCW and a concentrated copper waste (CCW) stream can be used as a copper source to produce azoles, metals (e.g., copper, cobalt, and iron), and a Fenton-like reagent (using Cu as a catalyst to generate hydroxyl radicals from H2O2 instead of iron in traditional Fenton reagent) for the treatment of silica solids in the wastewater. In some embodiments, the two wastewaters are mixed at a ratio of 1:25 (CCW:SCW) or greater, e.g., 1:10 (CCW:SCW) or greater. In some embodiments, additional copper, e.g., in the form of a copper sulfate solution, can be added to the combined CCW / SCW to provide additional copper to act as a catalyst in the Fenton-like reaction. In some embodiments, the combined CCW / SCW or combined CCW / SCW after administration of additional copper may contain 5,000 mg / L or more of dissolved copper, e.g., 6,000 mg / L or 7,000 mg / L or more of dissolved copper, or a copper:azole weight ratio in the wastewater being treated of up to 10:1, 15:1, or 20:1.

[0036] As mentioned above, wastewater from semiconductor manufacturing facilities or other industrial sources can contain high levels of azoles, for example, from about 20 mg / L up to about 200 mg / L or more, which are used as corrosion inhibitors for copper during wafer planarization and polishing processes. Wastewater from these processes can also contain heavy metals, additional organic compounds such as alcohols, and / or surfactants such as ammonium salts and inorganic abrasives such as colloidal silica, all of which should be removed before discharge. These additional contaminants can be present at levels of about 0.01 wt% to about 1 wt%. The wastewater also has high background total organic carbon (TOC) concentrations, with total azoles comprising a portion of the TOC. For example, oxidizers such as hydrogen peroxide (H2O2), commonly used to dissolve copper from microchips, can be present in CMP wastewater at concentrations exceeding 1,000 mg / L or 0.1 wt%.

[0037] Although azoles are not currently regulated by U.S. regulatory agencies at maximum contaminant levels (MCLs), they may present adverse environmental impacts when discharged into open waterways. Recent evidence indicates bioaccumulation of azoles in fish and toxicity in naturally occurring algal blooms, necessitating their removal from process waters prior to discharge.

[0038] As described in U.S. Patent No. 8,801,937, the entire disclosure of which is incorporated herein by reference, azole compounds are widely used in the semiconductor industry as corrosion inhibitors for copper during silicon wafer processing. Examples of such azole compounds include, but are not limited to, imidazole, pyrazole, oxazole, isoxazole, thiazole, isothiazole, selenazole, 1,2,3-triazole, 1,2,4-triazole, 1,2,5-oxadiazole, 1,3,4-oxadiazole, 1,2,3-thiadiazole, 1,2,4-thiadiazole, 1,3,4-thiadiazole, tetrazole, 1,2,3,4-thiatriazole, and any of their derivatives, amine salts, metals, etc. Examples of azole derivatives include compounds having a condensed ring such as an azole ring and a benzene ring, such as indazole, benzimidazole, benzotriazole, and benzothiazole, as well as alkylbenzotriazoles (e.g., benzotriazole, o-tolyltriazole, m-tolyltriazole, p-tolyltriazole, 5-ethylbenzotriazole, 5-n-propylbenzotriazole, 5-isobutylbenzotriazole, and 4-methylbenzotriazole), alkoxybenzotriazoles (e.g., 5-methoxybenzotriazole), alkylaminobenzotriazoles, and alkylaminosulfonylbenzotriazoles. and derivatives thereof, such as arylbenzotriazole, mercaptobenzotriazole, hydroxybenzotriazole, nitrobenzotriazole (e.g., 4-nitrobenzotriazole), halobenzotriazole (e.g., 5-chlorobenzotriazole), hydroxyalkylbenzotriazole, hydrobenzotriazole, aminobenzotriazole, (substituted aminomethyl)tolyltriazole, carboxybenzotriazole, N-alkylbenzotriazole, bisbenzotriazole, naphthatriazole, mercaptobenzothiazole, and aminobenzothiazole, as well as amine salts and metal salts thereof.

[0039] One embodiment of a system for treating azole-containing wastewater from a semiconductor fabrication facility is shown schematically in Figure 1. A semiconductor fabrication facility 110 typically contains hundreds of unit operations, three of which are shown in Figure 1. The unit operations shown in Figure 1 are a copper CMP unit operation 120, a unit operation 130 that produces high-concentration dissolved copper-containing wastewater, such as a copper plating operation, and a unit operation 140 that produces high-concentration hydrogen peroxide-containing wastewater, such as one of the wafer cleaning unit operations within the semiconductor fabrication facility 110. The disclosed system is used to decompose organic contaminants, such as azoles, present in the wastewater from the copper CMP unit operation 120 using a Fenton-like reaction that uses copper to catalyze the production of hydroxyl radicals from hydrogen peroxide. The hydroxyl radicals oxidatively decompose the organic contaminants, converting them into more harmless byproducts, such as nitrogen dioxide (NO2 / NO3), carbon dioxide, and water.

[0040] Wastewater from CMP unit operation 120 is directed to vessel 150, e.g., by pump P1. An oxidant, e.g., hydrogen peroxide from oxidant source 160, is added to the wastewater in vessel 150, e.g., using another pump P4, in an amount and rate sufficient to maintain a desired concentration of hydrogen peroxide in the vessel, e.g., 300 mg / L or greater, to promote the degradation of organic compounds in the wastewater. In some embodiments, the addition of oxidant from oxidant source 160 can be supplemented by the addition of hydrogen peroxide-containing wastewater from unit operation 140, e.g., using pump P3. If the hydrogen peroxide-containing wastewater from unit operation 140 contains sufficient hydrogen peroxide, it can be used as the sole source of hydrogen peroxide to be added to the wastewater in vessel 150.

[0041] In other embodiments, persulfates, such as ammonium persulfate, potassium persulfate, and / or sodium persulfate, may be utilized as the oxidizing agent. The aspects and embodiments disclosed herein are not limited by the type of oxidizing agent added to the treatment system. Peroxides generate hydroxyl and hydroperoxyl radicals when reacting with dissolved copper in vessel 150, and persulfates generate persulfate radicals.

[0042] A pH adjusting chemical source 170, e.g., a sulfuric acid and / or sodium hydroxide source, may add pH adjusting agents to the wastewater in vessel 150 in an amount and at a rate sufficient to maintain the pH of the wastewater in the vessel at a desired level, e.g., 2-4 or about 3, and promote the decomposition reaction of organic compounds in the wastewater.

[0043] A heater or heat exchanger 210 may also be present within the vessel and may be used to maintain the temperature of the wastewater within the vessel at a temperature suitable to promote the decomposition of organic compounds, such as azoles, in the wastewater via a Fenton-like reaction within a desired time period, which may be, for example, 55°C to 65°C or about 60°C.

[0044] The wastewater from CMP unit operation 120 may contain sufficient copper, for example, in the form of copper sulfate, to catalyze the production of hydroxyl radicals from hydrogen peroxide in vessel 150 in a Fenton-like reaction in which one or more organic species in the wastewater in vessel 150 are decomposed. Decomposition by-products of organic contaminants, such as nitrogen dioxide (NO2 / NO3) and carbon dioxide, may be vented from vessel 150 via vent V. The one or more organic species may include one or more azoles, such as 1,2,4-triazole, 1H-benzotriazole, or methylbenzotriazole:4,5-tolyltriazole, which may be present in the wastewater from CMP unit operation 120. The Fenton-like reagent used to decompose the azoles may contain 500 mg / L to 3,000 mg / L of an oxidant, such as hydrogen peroxide or persulfate, in a mixture of 50 mg / L to 300 mg / L of a soluble copper compound, such as copper sulfate (Cu 2+ )) to form the compound.

[0045] The Fenton-like reaction can proceed according to the following chemical formulas (1) to (3). JPEG2026505255000002.jpg53153

[0046] Cu 2+ Oxide of Cu 3+The persulfates and hydroxyl radicals, hydroperoxyl radicals, and persulfate radicals formed by the reduction of azoles react with the azoles in the CMP wastewater and decompose into primarily nitrogen dioxide (NO2 / NO3), carbon dioxide, and water. Without wishing to be bound by theory, the decomposition of nitrogenous organic molecules such as azoles may proceed according to the reaction shown in equation (4). JPEG2026505255000003.jpg20153

[0047] One or more sensors or monitors, e.g., temperature, pH, ORP, chemical concentration sensors, etc., collectively referred to as "S," may be provided in contact with the wastewater in vessel 150. The one or more sensors S may be in communication with controller 190. Controller 190 may be a conventional computer, e.g., equipped with an Intel Core® processor and running a conventional operating system, such as any version of Microsoft Windows®, and may be programmed to perform the functions disclosed herein. If desired, the controller may be or include a specially programmed controller, such as an application-specific integrated circuit (ASIC), programmed to perform the functions disclosed herein. Controller 190 is programmed or configured to control pH-adjusting chemical source 170 to introduce pH-adjusting chemical into vessel 150 in an amount and at a rate sufficient to maintain the pH of the wastewater in the vessel at a level at which copper catalyzes the production of hydroxyl radicals from the oxidizing agent. Controller 190 may also control the operation of heat exchanger or heater 210 and optional pumps P1-P7, such as controlling the introduction of wastewater from CMP unit operation 120, oxidant from oxidant source 160, CCW from unit operation 130, hydrogen peroxide-containing wastewater from unit operation 140, auxiliary copper solution from source 200, and removal of treated wastewater from vessel 150.

[0048] In some embodiments, the wastewater (SCW) from CMP unit operation 120 may not contain enough copper to catalyze the production of sufficient hydroxyl radicals to degrade organic contaminants in the wastewater from CMP unit operation 120 to a desired low level. Therefore, additional copper may be added to the wastewater in vessel 150 via pump P2 operated by controller 190, for example, from unit operation 130 having a high dissolved copper-containing wastewater (CCW). As noted above, in some embodiments, the two wastewaters may be mixed or introduced into vessel 150 in a ratio of 1:25 (CCW:SCW) or greater, for example, 1:10 (CCW:SCW) or greater. In some embodiments, additional copper, for example, in the form of a copper sulfate solution, may be added to the combined CCW / SCW from source 200, for example, via another pump P7, to provide additional copper to act as a catalyst in the Fenton-like reaction. In some embodiments, the combined CCW / SCW or combined CCW / SCW after administration of additional copper may contain 5,000 mg / L or more, e.g., 6,000 mg / L or 7,000 mg / L or more of dissolved copper, or a copper:azole weight ratio in the treated wastewater of up to 10:1, 15:1, 20:1 or more.

[0049] As disclosed herein, the wastewater from which organic compounds have been degraded and removed by the Fenton-like reaction in vessel 150 may be discharged from the vessel and directed, for example, by pump P6, to post-treatment system 180. Post-treatment system 180 may be used to remove residual copper and other unwanted components from the partially treated wastewater discharged from vessel 150 using methods known to those skilled in the art, producing treated water that may be discharged to the environment, recycled, or sent for further treatment or disposal.

[0050] Aspects and embodiments disclosed herein also relate to a method for removing organic compounds, e.g., one or more azoles, from a copper-containing solution, e.g., wastewater from a chemical mechanical polishing unit operation in a semiconductor manufacturing facility, using a Fenton-like reagent. The copper-containing solution may be produced from a mixture of wastewater from a copper chemical mechanical polishing (CMP) operation in the semiconductor manufacturing facility and a concentrated copper waste stream (CCW) from the semiconductor manufacturing facility. The method may include introducing an oxidizing agent into the copper-containing solution, where the copper catalyzes the production of hydroxyl radicals from the oxidizing agent, as the oxidizing agent reacts with the organic compounds. The pH of the copper-containing solution in the vessel may be maintained at a level, e.g., 2 to 4, at which the copper catalyzes the production of hydroxyl radicals from the oxidizing agent. The temperature of the copper-containing solution in the vessel may be maintained at about 55°C to about 65°C. The step of introducing the oxidizing agent into the copper-containing solution may include introducing hydrogen peroxide into the copper-containing solution. The concentration of hydrogen peroxide in the copper-containing solution in the vessel may be maintained at 250 mg / L or greater. The hydrogen peroxide may be obtained from a waste stream from the semiconductor manufacturing facility. Producing the copper-containing solution may include mixing at least 1 part CCW with 25 parts CMP wastewater or at least 1 part CCW with 10 parts CMP wastewater. Producing the copper-containing solution may include combining CCW with CMP wastewater in an amount sufficient to provide 10 parts by weight of copper per 1 part by weight of the one or more azole compounds. Removing organic compounds from the copper-containing solution may include removing one or more of 1,2,4-triazole, 1H-benzotriazole, or methylbenzotriazole:4,5-tolyltriazole from the copper-containing solution. [Example]

[0051] Analysis of CMP slurry wastewater (slurry copper wastewater: SCW) and wastewater with high concentrations of Cu (concentrated copper waste: CCW), as well as a 25:1 mixture of SCW and CCW, from a semiconductor manufacturing facility, has revealed the presence of the contaminants listed in Table 1 below.

[0052] [Table 1]

[0053] Tests were conducted to determine whether copper in a 25:1 mixture of SCW and CCW was present in sufficient amounts to catalyze the production of enough hydroxyl radicals to decompose the 1,2,4-triazole present in the mixture. Test conditions and results are detailed in Table 2 below.

[0054] [Table 2]

[0055] The pH of the combined sample (962 mL SCW + 38 mL CCW) was 3.0. A cumulative HO dose of 1,680 mg / L over a 120-minute reaction time resulted in 90% TOC removal and 0.38 mg / L azole residual (99% removal). These results were achieved without added iron, demonstrating that copper, already present in wastewater streams from semiconductor manufacturing facilities, can be utilized as a catalyst in a Fenton-like reaction to effectively remove organic pollutants, including azoles, from the same wastewater stream. [Example]

[0056] Further testing was conducted to evaluate whether the Fenton-like reaction disclosed herein could successfully degrade organic compounds, such as azoles, in wastewater from a semiconductor manufacturing facility under conditions that simulate worst-case contaminant concentrations in the wastewater. 1,2,4-triazole was further added to 25:1 SCW:CCW and 10:1 SCW:CCW wastewater mixtures to yield wastewater mixtures with copper and azole concentrations as shown in Table 3 below.

[0057] [Table 3]

[0058] The test conditions and results for TOC removal from wastewater simulating the worst case are shown in Table 4 below.

[0059] [Table 4]

[0060] The 10:1 mixture removed more TOC than the 25:1 mixture, but still only 32% TOC removal. An additional Fenton-like reaction test was performed to determine the copper-to-azole ratio that would correspond to approximately 70% TOC removal, i.e., greater than 90% azole removal. Extrapolating the copper to azole ratio versus TOC removal from these results, the required copper concentration was determined to be approximately 7,000 mg / L, or approximately 20 copper / azole by weight.

[0061] This Fenton-like reaction test was performed on a 25:1 mixture containing 690 mg / L Cu, with 6,330 mg / L Cu (9,582 mg / L CuSO4) added. The results are shown in Table 5, along with the results of the same mixture without added copper for comparison.

[0062] [Table 5]

[0063] The addition of copper at the start of the test significantly improved the TOC removal rate, suggesting that a copper / azole ratio of 20 or higher may be able to effectively decompose organic compounds in mixed SCW:CCW wastewater via a Fenton-like reaction.

[0064] The phrases and terms used herein are for descriptive purposes and should not be construed as limiting. As used herein, the term "plurality" refers to two or more items or components. Terms such as "comprise," "include," "hold," "have," "contain," "involve," and the like, whether in the specification or claims, are open-ended terms, i.e., meaning "including, but not limited to." Thus, the use of such terms is intended to encompass the subsequently listed items and their equivalents, as well as additional items. Only the transitional phrases "consisting of" and "consisting essentially of," respectively, are closed or semi-closed transitional phrases in the claims. The use of ordinal numbers such as "first," "second," and "third" to modify claim elements in the claims does not, in and of itself, imply that one claim element has a priority, precedence, or order in which method actions are performed relative to other claim elements, but is used merely as a label to distinguish one claim element having a particular name from another element having the same name (but using an ordinal number).

Claims

1. 1. A method for removing organic compounds from a copper-containing solution, comprising: generating the copper-containing solution from a mixture of wastewater from a copper chemical mechanical polishing (CMP) operation at a semiconductor fabrication facility and a concentrated copper waste stream (CCW) from the semiconductor fabrication facility; introducing an oxidizing agent into the copper-containing solution; A method for removing organic compounds from a copper-containing solution, wherein the copper catalyzes the production of hydroxyl radicals from the oxidizing agent that react with the organic compounds.

2. 10. The method of claim 1, further comprising the step of maintaining a pH of the copper-containing solution in a container at a level at which the copper catalyzes the production of the hydroxyl radicals from the oxidizing agent.

3. 3. The method of claim 2, further comprising maintaining the pH of the copper-containing solution in the vessel in the range of about 2 to about 4.

4. 10. The method of claim 1, further comprising maintaining the temperature of the copper-containing solution at about 55°C to about 65°C.

5. The method of claim 1 , wherein the step of introducing an oxidizing agent to the copper-containing solution comprises introducing hydrogen peroxide to the copper-containing solution.

6. 6. The method of claim 5, further comprising the step of maintaining a concentration of hydrogen peroxide in the copper-containing solution in the vessel at 250 mg / L or greater.

7. 6. The method of claim 5, further comprising obtaining the hydrogen peroxide from a waste stream from the semiconductor manufacturing facility.

8. 10. The method of claim 1, wherein the step of producing the copper-containing solution comprises mixing at least 1 part of the CCW with 25 parts of the CMP wastewater.

9. 10. The method of claim 1, wherein removing the organic compounds from the copper-containing solution comprises removing one or more azole compounds from the copper-containing solution.

10. 10. The method of claim 9, wherein the step of producing the copper-containing solution comprises mixing the CCW with the CMP wastewater in an amount sufficient to provide 20 parts by weight of copper per 1 part by weight of the one or more azole compounds.

11. 10. The method of claim 9, wherein removing the organic compounds from the copper-containing solution comprises removing one or more of 1,2,4-triazole, 1H-benzotriazolepyrazole, benzotriazole, 5-methyl-1H-benzotriazole (tolutriazole), or 3-amino-1,2,4-triazole from the copper-containing solution.

12. 1. A system for removing organic compounds from wastewater from a semiconductor manufacturing facility, the system comprising: a container fluidly connectable to a source of said wastewater; a copper source configured to introduce copper into the wastewater in the vessel, the copper source comprising a concentrated copper waste stream from the semiconductor fabrication facility; an oxidant source configured to introduce the oxidant into the wastewater in the vessel; a pH-adjusting chemical source configured to introduce a pH-adjusting chemical into the wastewater in the vessel.

13. a pH monitor disposed within the vessel; a controller configured to control the pH adjusting chemical source to introduce the pH adjusting chemical into the wastewater in the vessel in an amount and at a rate sufficient to maintain the pH of the wastewater in the vessel at a level at which the copper catalyzes the production of hydroxyl radicals from the oxidizing agent; The system of claim 12 further comprising:

14. 14. The system of claim 13, wherein the controller is configured to control the pH-adjusting chemical source to introduce the pH-adjusting chemical into the wastewater in the vessel in an amount and at a rate sufficient to maintain the pH of the wastewater at about 2 to about 4.

15. The system of claim 13 , further comprising a heater, wherein the controller is further configured to control the heater to maintain a temperature of the wastewater in the vessel between about 55° C. and about 65° C.

16. 14. The system of claim 13, wherein the oxidant source is a hydrogen peroxide source, and the controller is further configured to control the oxidant source to maintain a concentration of hydrogen peroxide in the wastewater in the vessel at or above 250 mg / L.

17. 17. The system of claim 16, wherein the source of hydrogen peroxide comprises a waste stream from the semiconductor manufacturing facility.

18. 13. The system of claim 12, wherein the wastewater contains one or more copper corrosion inhibitors, and the system is configured such that the copper acts as a catalyst for the generation of hydroxyl radicals, and the hydroxyl radicals generated from the oxidizing agent decompose the copper corrosion inhibitors.

19. 13. The system of claim 12, wherein the wastewater contains one or more azole compounds, and the system is configured such that the copper acts as a catalyst for the generation of hydroxyl radicals, and the hydroxyl radicals generated from the oxidizing agent decompose the one or more azoles.

20. 13. The system of claim 12, wherein the wastewater contains one or more of 1,2,4-triazole, 1H-benzotriazolepyrazole, benzotriazole, 5-methyl-1H-benzotriazole (tolutriazole), or 3-amino-1,2,4-triazole, and the system is configured such that the copper acts as a catalyst for the generation of hydroxyl radicals, and the hydroxyl radicals generated from the oxidant decompose the one or more of 1,2,4-triazole, 1H-benzotriazolepyrazole, benzotriazole, tolutriazole, or 3-amino-1,2,4-triazole.

21. 13. The system of claim 12, wherein the wastewater source is a unit operation of the semiconductor manufacturing facility.

22. 13. The system of claim 12, wherein the wastewater source is a copper CMP operation of the semiconductor manufacturing facility.

23. 13. The system of claim 12, wherein the copper source comprises a copper plating operation of the semiconductor manufacturing facility.

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